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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM10-K


ý

ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF1934OF 1934
For the fiscal year ended December 31, 2020
or

For the fiscal year ended December 31, 2017

or

o

TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from                                        to                                         

For the transition period from              to              
Commission File Number:001-35358

TC PipeLines, LP
(Exact name of registrant as specified in its charter)

Delaware
52-2135448
State or other jurisdiction

of incorporation or organization
52-2135448
(I.R.S. Employer

Identification No.)

700 Louisiana StreetSuite 700
77002-2761
Houston,Texas
(Zip code)
(Address of principal executive offices)
877-290-2772
(Registrant’s telephone number, including area code)
Securities registered pursuant to Section 12(b) of the Act:

77002-2761
(Zip code)

877-290-2772
(Registrant's telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Title of each class
Common units representing limited partner interestsClass

Trading Symbol

Name of each exchange on which registered
New York Stock Exchange

Securities registered pursuant to Section 12(g) of the Act:
NoneCommon units representing limited partner interests
TCPNYSE

Securities registered pursuant to Section 12(g) of the Act:
None
Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.Yes ýxNo o

¨

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes o¨No ý

x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.Yes ýxNo o

¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).Yes ýxNo o

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not contained herein, and will not be contained, to the best of registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.    ý

¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large“large accelerated filer," "accelerated” “accelerated filer," "smaller” “smaller reporting company"company” and "emerging“emerging growth company"company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer ýAccelerated FilerxAccelerated filero¨Non-accelerated filer o
(Do not check if a small reporting company)
¨Smaller Reporting Company o
Emerging Growth Company o

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o

¨


Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. x
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes oNo ý

x

The aggregate market value of the common units of the registrant held by non-affiliates as of June 30, 20172020 was approximately $2.9$ 2.2 billion.

As of February 22, 2018,19, 2021, there were 71,306,396 common units of the registrant outstanding.





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DOCUMENTS INCORPORATED BY REFERENCE

None



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TC PIPELINES, LP


TABLE OF CONTENTS

Page No.

Page No.
Business7
25
42
Properties42
42
43

PART II




44
45
Management's46
72
74
74
74
75

PART III




75
80
83
84
88

PART IV




90

Signatures




95

All amounts are stated in United States dollars unless otherwise indicated.

TC PipeLines, LPAnnual Report2017     2020     3


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DEFINITIONS

The abbreviations, acronyms, and industry terminology used in this annual report are defined as follows:

2013 AcquisitionAcquisition of an additional 45 percent membership interest in each of GTN and Bison by the Partnership to increase ownership to 70 percent on July 1, 2013

2013 Term Loan Facility


TC PipeLines, LP'sLP’s $500 million term loan credit facility under a term loan agreement as amended on September 29, 2017

2015 GTN Acquisition


Partnership's acquisition of the remaining 30 percent interest in GTN on April 1, 2015

2015 Term Loan Facility


TC PipeLines, LP'sLP’s $170 million term loan credit facility under a term loan agreement as amended on September 29, 2017

2016 PNGTS Acquisition


Partnership's acquisition of a 49.9 percent interest in PNGTS, effective January 1, 2016

2017 Acquisition


Partnership'sPartnership’s acquisition of an additional 11.81 percent interest in PNGTS and 49.34 percent in Iroquois on June 1, 2017

2017 Great Lakes Settlement

Stipulation and Agreement of Settlement for Great Lakes regarding its rates and terms and conditions of service approved by FERC on February 22, 2018

2017 Northern Border Settlement

Stipulation and Agreement of Settlement for Northern Border regarding its rates and terms and conditions of service approved by FERC on February 23, 2018

2017 Tax Act

H.R.1, originallyPublic Law No. 115-97, commonly known as the Tax Cuts and Jobs Act, enacted on December 22, 2017.2017

AFUDC


2018 FERC ActionsFERC’s 2018 issuance of Revised Policy Statement on Treatment of Income Taxes (Revised Policy Statement) and a Final Rule that established a schedule by which interstate pipelines must either (i) file a new uncontested rate settlement or (ii) file a one-time report, called FERC Form No. 501-G, that quantified the rate impact of the 2017 Tax Act on FERC regulated pipelines and the impact of the Revised Policy Statement on pipelines held by an MLP
2018 GTN SettlementStipulation and Agreement of Settlement for GTN regarding its rates and terms and conditions of service approved by FERC on November 30, 2018
2019 Iroquois SettlementAn uncontested settlement filed by Iroquois with FERC to address the issues contemplated by the 2017 Tax Act and the 2018 FERC Actions via an amendment to its prior 2016 settlement approved by FERC on May 2, 2019
2019 Tuscarora SettlementAn uncontested settlement filed by Tuscarora with FERC to address the issues contemplated by the 2017 Tax Act and the 2018 FERC Actions via an amendment to its prior 2016 settlement approved by FERC on May 2, 2019
ADITAccumulated Deferred Income Tax
Adjusted EBITDAEBITDA, less (1) earnings from our equity investments, plus (2) distributions from our equity investments, and plus or minus (3) certain non-recurring items (if any) that are significant but not reflective of our underlying operations
AFUDCAllowance for funds used during construction

ASC


ANRANR Pipeline Company
ASCAccounting Standards Codification

ASU


Accounting Standards Update

ATM program


At-the-market Equity Issuance Program

Bison


BIABureau of Indian Affairs
BisonBison Pipeline LLC

C2C Contracts

PNGTS'PNGTS’ Continent-to-Coast Contracts with several shippers for a term of 15 years for approximately 82,000 Dth/day

Canadian Mainline

TransCanada'sTC Energy’s Mainline, a natural gas transmission system extending from the Alberta/Saskatchewan border east to Quebec

Carty Lateral


GTN lateral pipeline in north-central Oregon that delivers natural gas to a power plant owned by Portland General Electric Company

Certificate Policy Statement NOI
FERC Notice of Inquiry issued on April 19, 2018
Class B DistributionAnnual distribution to TC Energy based on 30 percent of GTN’s annual distributions as follows: (i) 100 percent of distributions above $20 million through March 31, 2020; and (ii) 25 percent of distributions above $20 million thereafter
Class B ReductionApproximately 35 percent reduction applied to the estimated annual Class B Distribution beginning in 2018, which is equivalent to the percentage by which distributions payable to the common units were reduced in 2018. The Class B Reduction will continue to apply for any particular calendar year until distributions payable in respect of common units for such calendar year equal or exceed $3.94 per common unit
Consolidated Subsidiaries

GTN, Bison, North Baja, Tuscarora and PNGTS

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COVID-19Coronavirus 2019
Delaware Act

Delaware Revised Uniform Limited Partnership Act

DOT


DOTU.S. Department of Transportation

DSUsDeferred Share Units
Dth/day

Dekatherms per day

DSUs


Deferred Share Units

EBITDA


Earnings Before Interest, Tax, Depreciation and Amortization

EPA


EPAU.S. Environmental Protection Agency

FASB


ExC ProjectIroquois Enhancement by Compression project that involves upgrading its compressor stations along the pipeline and provide approximately 125,000 Dth/day of additional firm transportation service to meet current and future gas supply needs of utility customers
FASBFinancial Accounting Standards Board

FERC


FERCFederal Energy Regulatory Commission

GAAP


GAAPU.S. generally accepted accounting principles

General Partner

TC PipeLines GP, Inc.

GHG


GHGGreenhouse Gas

4    TC PipeLines, LPAnnual Report2017



Great Lakes

Great Lakes Gas Transmission Limited Partnership

GTN


GTNGas Transmission Northwest LLC

HCAs


GTN XPressGTN's projects designed to both increase the reliability of existing transportation service including 100,000 Dth/day of existing transportation service on GTN and provide for a total of 150,000 Dth/day of incremental transportation capacity, primarily through facility replacements and additions of existing brownfield compression sites.
HCAsHigh consequence areas

IDRs


IDRsIncentive Distribution Rights

IRS


IroquoisIroquois Gas Transmission System, L.P.
IRSInternal Revenue Service

Joint Facilities

Pipeline facilities jointly owned with MNE on PNGTS

KPMG


KPMG LLP

LDCsKPMG

KPMG LLP

LDCsLocal Distribution Companies

LIBOR


LIBORLondon Interbank Offered Rate

LNG


LNGLiquefied Natural Gas

MNE


MLPsMaster limited partnerships
MNEMaritimes and Northeast Pipeline LLC, a subsidiary of Enbridge Inc.

MNOC


MNOCM&N Operating Company, LLC, a wholly owned subsidiary of MNE

NGA


Moody'sMoody's Investors Service
NGANatural Gas Act of 1938

North Baja

North Baja Pipeline, LLC

North Baja XPressNorth Baja project to transport additional volumes of natural gas of approximately 495,000 Dth/day between Ehrenberg, Arizona and Ogilby, California
Northern Border

Northern Border Pipeline Company

NYSE


NYSENew York Stock Exchange

Our pipeline systems

Our ownership interests in GTN, Northern Border, Bison, Great Lakes, North Baja, Tuscarora, PNGTS and Iroquois

Partnership


PartnershipTC PipeLines, LP, including its subsidiaries, as applicable
TC PipeLines, LP Annual Report 2020     5

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Partnership Agreement

ThirdFourth Amended and Restated Agreement of Limited Partnership of the Partnership

PHMSA


PHMSAU.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration

PNGTS


PNGTSPortland Natural Gas Transmission System

PXP


PXPPortland XPress Project of PNGTS to re-contract certain system capacity set to expire in 2019 as well as construct incremental compression facilities within PNGTS’ existing footprint in Maine

SEC


Revised Policy StatementFERC's Revised Policy Statement on Treatment of Income Taxes
ROEReturn on equity
SECSecurities and Exchange Commission

Securities ActSecurities Act of 1933, as amended
Senior Credit Facility

TC PipeLines, LP'sLP’s senior facility under revolving credit agreement as amended and restated, dated September 29, 2017

TQM


S&PStandard & Poor's
TC EnergyTC Energy Corporation, formerly known as TransCanada Corporation
TC Energy Merger AgreementTC Energy's definitive agreement with the Partnership to acquire all outstanding common units of the Partnership not beneficially owned by TC Energy via stock exchange whereby the Partnership's common unitholders would receive 0.70 common shares of TC Energy for each issued and outstanding publicly-held Partnership common unit.
TC Energy MergerThe merger of TCP Merger Sub, LLC with and into the Partnership, with the Partnership continuing as the sole surviving entity and an indirect, wholly owned subsidiary of TC Energy.
TQMTransQuebec and Maritimes Pipeline

TransCanada


TransCanada Corporation and its subsidiaries

TransCanada PXP ExpendituresTuscarora


TransCanada's latest estimate of $107 million of upstream capacity capital expenditures that PNGTS may be responsible for in the event the Portland Express Project does not proceed.

Tuscarora


Tuscarora Gas Transmission Company

Tuscarora Settlement


Stipulation and Agreement of Settlement for Tuscarora regarding its rates and terms and conditions of service approved by FERC on September 22, 2016

U.S.Tuscarora XPress

Tuscarora's expansion project through additional compression capability at an existing Tuscarora facility and provide up to 15,000 Dth/day of additional firm transportation service

Unaffiliated TCP UnitholdersHolders of the outstanding Partnership common units, other than TC Energy and its affiliates
U.S.United States of America

WCSB


WCSBWestern CanadaCanadian Sedimentary Basin

Wholly-owned
Westbrook XPressWestbrook XPress Project of PNGTS that is part of a coordinated offering to transport incremental Western Canadian Sedimentary Basin natural gas supplies to the Northeast U.S. and Atlantic Canada markets through additional compression capability at an existing PNGTS facility
Wholly owned subsidiaries

GTN, Bison, North Baja, and Tuscarora
WHOWorld Health Organization

Unless the context clearly indicates otherwise, TC PipeLines, LP and its subsidiaries are collectively referred to in this annual report as "we," "us," "our"“we,” “us,” “our”, TC PipeLines and "the“the Partnership." We use "our“our pipeline systems"systems” and "our pipelines"“our pipelines” when referring to the Partnership'sPartnership’s ownership interests in Gas Transmission Northwest LLC (GTN), Northern Border Pipeline Company (Northern Border), Bison Pipeline LLC (Bison), Great Lakes Gas Transmission Limited Partnership (Great Lakes), North Baja Pipeline, LLC (North Baja), Tuscarora Gas Transmission Company (Tuscarora), Portland Natural Gas Transmission System (PNGTS) and Iroquois Gas Transmission System, LP (Iroquois).

6     TC PipeLines, LPAnnual Report2017    5

 2020

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PART I

FORWARD-LOOKING STATEMENTS AND CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION


This report includes certain forward-looking statements.statements, including statements regarding the potential TC Energy Merger and the Partnership, such as any statements regarding the expected timetable for completing the transaction. Forward-looking statements are identified by words and phrases such as: "anticipate," "estimate," "expect," "project," "intend," "plan," "believe," "forecast," "should," "predict," "could," "will," "may,"“anticipate,” “assume,“ “estimate,” “expect,” “project,” “intend,” “plan,” “believe,” “forecast,” “should,” “predict,” “could,” “will,” “may,” and other terms and expressions of similar meaning. The absence of these words, however, does not mean that the statements are not forward-looking. These statements are based on management'smanagement’s beliefs and assumptions and on currently available information and include, but are not limited to, statements regarding anticipated financial performance, future capital expenditures, liquidity, dropdown opportunities, market or competitive conditions, regulations, organic or strategic growth opportunities, contract renewals and ability to market open capacity, business prospects, outcome of regulatory proceedings and cash distributions to unitholders.


Forward-looking statements involve risks and uncertainties that may cause actual results to differ materially from the results predicted. Factors that could cause actual results and our financial condition to differ materially from those contemplated in forward-looking statements include, but are not limited to:

the ability of our pipeline systems to sell available capacity on favorable terms and renew expiring contracts which are affected by, among other factors:

demand for natural gas;

changes in relative cost structures and production levels of natural gas producing basins;

natural gas prices and regional differences;

weather conditions;

availability and location of natural gas supplies in Canada and the United States (U.S.) in relation to our pipeline systems;

competition from other pipeline systems;

natural gas storage levels; and

rates and terms of service;

the performance by therefusal or inability of our customers, shippers ofor counterparties to perform their contractual obligations on our pipeline systems;

with us, whether justified or not and whether due to financial constraints (such as reduced creditworthiness, liquidity issues or insolvency), market constraints, legal constraints (including governmental orders or guidance), the exercise of contractual or common law rights that allegedly excuse their performance (such as force majeure or similar claims) or other factors;
the outcome and frequency of rate proceedings or settlement negotiations on our pipeline systems;

the impact of the 2017 Tax Act enacted on December 22, 2017 on our future operating performance;

other potential changes in the taxation of master limited partnership (MLP) investments by state or federal governments such as the elimination of pass-through taxation or tax deferred distributions;

increases in operational or compliance costs resulting from changes in laws and governmental regulations affecting our pipeline systems, particularly regulations issued by the Federal Energy Regulatory Commission (FERC), U.S. Environmental Protection Agency (EPA) and U.S. Department of Transportation (DOT);

the impact of downward changes in oil and natural gas prices, including the effects on the creditworthiness of our shippers;

our ongoing ability to grow distributions through acquisitions, accretive expansionsshippers or other growth opportunities, including the timing, structure and closureavailability of further potential acquisitions;

associated gas in a low commodity price environment;
potential conflicts of interest between TC PipeLines GP, Inc., our general partner (General Partner), TransCanadaTC Energy Corporation (TC Energy) and us;

failure of the Partnership or our pipeline systems to comply with debt covenants, some of which are beyond our control;
the ability to maintain secure operation of our information technology including management of cybersecurity threats, acts of terrorism and related distractions;

6    TC PipeLines, LPAnnual Report2017


the expected impactimplementation of future accounting changes and ultimate outcome of commitments and contingent liabilities (if any);

the impact of any impairment charges;

changes in the political environment;

operating hazards, casualty losses and other matters beyond our control;

the overall increase in the allocated management and operational expenses to our pipeline systems for services performed by TransCanada; and

TC Energy; 
TC PipeLines, LP Annual Report 2020     7

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ability of our pipeline systems to renew rights-of-way at a reasonable cost;
the level of our indebtedness including(including the indebtedness of our pipeline systems, increasesystems), increases in interest rates, our level of interest rates,operating cash flows and the availability of capital.

capital;

the impact of a potential slowdown in construction activities or a delay in the completion of our capital projects including increases in costs and availability of labor, equipment and materials;
the impact of litigation and other opposition proceedings on our ability to begin work on projects and the potential impact of an ultimate court or administrative ruling to a project schedule or viability;
uncertainty surrounding the impact of global health crises that reduce commercial and economic activity, including the COVID-19 pandemic, on our business;
the impact of market disruptions relating to global supply and demand for oil and natural gas;
the impact of TC Energy's planned acquisition of all the Partnership's outstanding common units not beneficially owned by TC Energy; and
the timing and ability of TC Energy or the Partnership to consummate the TC Energy Merger.
These and other risks are described in greater detail in Part I, Item 1A. "Risk“Risk Factors." Given these uncertainties, you should not place undue reliance on these forward-looking statements. All forward-looking statements attributable to us or persons acting on our behalf are expressly qualified in their entirety by these factors. All forward-looking statements are made only as of the date made and except as required by applicable law, we undertake no obligation to update any forward-looking statements to reflect new information, subsequent events or other changes.

Item 1. Business

NARRATIVE DESCRIPTION OF BUSINESS

General

GENERAL
We are a publicly traded Delaware master limited partnership. Our common units trade on the New York Stock Exchange (NYSE) under the symbol TCP."TCP". We were formed by TransCanada CorporationTC Energy and its subsidiaries (TransCanada) in 1998 to acquire, own and participate in the management of energy infrastructure businesses in North America. Our pipeline systems transport natural gas in the U.S.

We are managed by our General Partner, which is an indirect, wholly-ownedwholly owned subsidiary of TransCanada.TC Energy. At December 31, 2017,2020, subsidiaries of TransCanada ownTC Energy owned approximately 24.224 percent of our common units, 100 percent of our Class B units, 100 percent of our incentive distribution rights (IDRs) and an effectivehold a two percent general partner interest in us. See Part II, Item 5. "Market“Market for Registrant'sRegistrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities"Securities” for more information regarding TransCanada'sTC Energy's ownership in us.

Recent Business Developments

Cash Distribution – Our annual cash distribution declared per

RECENT BUSINESS DEVELOPMENTS
Planned merger with TC Energy:

On October 5, 2020, the Partnership announced receipt of a non-binding offer from TC Energy to acquire all of its outstanding common unit increasedunits not beneficially owned by six percent from $3.71 perTC Energy, or its affiliates, in exchange for common unit in 2016shares of TC Energy. Under the initial proposal, holders of the outstanding TC PipeLines common units, other than TC Energy and its affiliates, (the Unaffiliated TCP Unitholders) would receive 0.65 common shares of TC Energy for each issued and outstanding publicly-held Partnership common unit.
The offer was made to $3.94 per common unit in 2017.

On April 25, 2017, the board of directors of the General Partner (TC PipeLines Board). As the general partner of the Partnership is an indirect wholly owned subsidiary of TC Energy, a conflicts committee composed of independent directors of the TC PipeLines Board (the Conflicts Committee) was formed to consider the offer pursuant to the Fourth Amended and Restated Agreement of Limited Partnership of the Partnership (Partnership Agreement).

On December 14, 2020, the Partnership, the General Partner, TC Energy, TransCan Northern Ltd., a Delaware corporation (TC Northern), TransCanada PipeLine USA Ltd., a Nevada corporation (TC PipeLine USA), and TCP Merger Sub, LLC, a Delaware limited liability company and an indirect wholly owned subsidiary of TC Energy (Merger Sub), entered into an Agreement and Plan of Merger (the TC Energy Merger Agreement). Pursuant to the TC Energy Merger Agreement, Merger Sub will be merged with and into the Partnership (TC Energy Merger), with the Partnership continuing as the sole surviving entity and an indirect wholly owned subsidiary of TC Energy.
Subject to the terms and conditions set forth in the TC Energy Merger Agreement, at the effective time of the TC Energy Merger, each common unit representing a fractional part of the limited partner interests in the Partnership issued and outstanding immediately prior to the effective time of the TC Energy Merger held by an Unaffiliated TCP Unitholder, will be cancelled in exchange for 0.70 shares of TC Energy’s common shares.
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The Conflicts Committee has approved the TC Energy Merger Agreement and the transactions contemplated thereby and recommended that the Board direct that the TC Energy Merger Agreement be submitted to a vote of the limited partners for their approval at a special meeting and recommended that the Board recommend to the limited partners of the Partnership that the limited partners approve the TC Energy Merger Agreement and the TC Energy Merger.
Based upon such recommendation, the Board has directed that the TC Energy Merger Agreement and the transactions contemplated thereby, including the TC Energy Merger, be submitted to the limited partners for their approval at a special meeting, to be held at 10:00 a.m. Central Time, on February 26, 2021. See Part I, Item 1A. “Risk Factors” for a discussion of the risks related to the TC Energy Merger. For additional information regarding the TC Energy Merger Agreement and the TC PipeLines Board’s process and rationale for the TC Energy Merger, please see the definitive proxy statement filed with the Securities Exchange Commission on January 26, 2021 and other documents filed with the Securities and Exchange Commission when they become available.

COVID-19

On March 11, 2020, the WHO declared COVID-19, a global pandemic. As the primary operator of our pipelines, TC Energy’s business continuity plans remain in place across the organization and TC Energy continues to effectively operate our assets, conduct commercial activities and execute on projects with a focus on health, safety and reliability. Our business is broadly considered essential in the United States given the important role our infrastructure plays in providing energy to North American markets. We believe that TC Energy’s robust continuity and business resumption plans for critical teams, including gas control and commercial and field operations, will continue to ensure the safe and reliable delivery of energy that our customers depend upon.
Our pipeline assets are largely backed by long-term, take-or-pay contracts resulting in revenues that are materially insulated from short-term volatility associated with fluctuations in volume throughput and commodity prices. More importantly, a significant portion of our long-term contract revenue is with investment-grade customers and we have not experienced any material collection issues on our receivables to date. Aside from the impact of maintenance activities and normal seasonal factors, to date we have not seen any material changes in the utilization of our assets. Additionally, to date, we have not experienced any significant impacts on our supply chain. While it is too early to ascertain any long-term impact that the COVID-19 pandemic may have on our capital growth program, we note that we could experience some delay in construction and other related activities.
Capital market conditions in 2020 were significantly impacted by COVID-19 resulting in periods of extreme volatility and reduced liquidity. Despite these challenges, our liquidity remains strong, underpinned by stable cashflow from operations, cash on hand and full access to our $500 million Senior Credit Facility. The recently concluded transactions described below demonstrate our continued access to the debt capital markets at attractive levels:
During the second quarter of 2020, GTN's $100 million senior notes due in June 2020 were refinanced through a Note Purchase Agreement whereby GTN issued $175 million of 10-year Series A Senior Notes with a coupon rate of 3.12% with the incremental $75 million of proceeds to be used to fund the GTN XPress Project through the balance of 2020. Additionally, GTN entered into a 3-year private shelf agreement for a further $75 million which will be used to finance a portion of the GTN XPress Project into 2023;
During the third quarter of 2020, Tuscarora's $23 million unsecured term loan due in August 2020 was extended for one year to August 2021 under generally the same terms; and
During the fourth quarter of 2020, PNGTS entered into a Note Purchase Agreement whereby PNGTS issued $125 million 10-year Series A Senior Notes with a coupon rate of 2.84%, the proceeds of which were primarily used to repay the outstanding balance of PNGTS' revolving credit facility. The remaining proceeds were used for general partnership purposes, including the funding of the Portland XPress project (PXP) and the Westbrook XPress project. PNGTS also entered into a 3-year private shelf agreement for an additional $125 million which will be used to finance the remaining capital spending required for the Westbrook XPress project into 2021.
We continue to conservatively manage our financial position, self-fund our ongoing capital expenditures and maintain our debt at prudent levels and we believe we are well positioned to fund our obligations through a prolonged period of disruption, should it occur. Based on current expectations, we believe our business will continue to deliver consistent financial performance going forward and support our current quarterly distribution level of $0.65 per common unit.

The full extent and lasting impact of the COVID-19 pandemic on the global economy is uncertain but to date has included extreme volatility in financial markets and commodity prices, a significant reduction in overall economic activity and widespread extended shutdowns of businesses along with supply chain disruptions. The degree to which the COVID-19 pandemic has a more significant longer-term impact on our operations and growth projects will depend on future developments, policies and actions which remain highly uncertain. Additional information regarding risks and impacts on our business can be found throughout this section, including Part I, Item 1A - "Risk Factors" and Part II, Item 7A - "Quantitative and Qualitative Disclosures About Market Risk."

Impairment considerations:

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Under U.S. GAAP, we evaluate our goodwill related to Tuscarora and North Baja for impairment at least annually or more frequently if any indicators of impairment are evident. Our long-lived assets and equity investments are evaluated whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable.

On a quarterly basis during 2020, we evaluated changes within our business and the external environment including considerations regarding whether such changes are permanent, to determine whether a triggering event had occurred. This analysis included the quarterly assessment of the impact of COVID-19 to our reporting units and equity investments. Through our quarterly analyses, no triggering events were identified.
The following factors were considered in our analysis specific to the Partnership:
a significant amount of our pipeline assets’ revenue is tied to long-term take-or-pay, fixed-price contracts which have a low correlation to short-term changes in demand;
we have not experienced any material customer defaults to date and we hold collateral, as appropriate, to support our contracts;
we evaluated the multiples and discount rate assumptions within the current economic environment and compared to the previous quantitative model used for our North Baja and Tuscarora reporting units. The multiples and discount rates identified for the current year used in our qualitative model are reflective of the long-term outlook for Tuscarora and North Baja, in line with their underlying asset lives;
while we may experience a slowdown in some of our construction activities, our current growth projects are materially on track, and we do not anticipate any significant changes in outlook, delays or inability to proceed due to financing requirements; and
our businesses are broadly considered essential in the United States given the important role these pipeline infrastructure assets play in delivering energy to the market areas we serve.
While the issues described above continue to persist, we continue to believe no impairment exists on our goodwill, equity investments or long-lived assets. However, future adverse changes to our key considerations could change our conclusion.
Growth Projects Update:
PNGTS’ Portland XPress Project (PXP) - PXP was initiated in 2017 in order to expand deliverability on the PNGTS system to Dracut, Massachusetts through re-contracting and construction of incremental compression within PNGTS’ existing footprint in Maine. PXP was designed to be phased in over a three-year time period. Phases I and II were placed into service in 2018 and 2019, respectively, with the final Phase III placed into service during the fourth quarter of 2020. Beginning in 2021, PXP is expected to generate approximately $50 million in annual revenue for PNGTS. The total final volume of the project is approximately 183,000 Dth/day; 40,000 Dth/day from Phase I, 118,400 Dth/day from Phase II, which includes re-contracting and renewal of expiring contracts, and 24,600 Dth/day from Phase III. PXP is secured by long-term agreements and now that all phases of the project are in service, PNGTS is effectively fully contracted until 2032.
Additionally, in connection with PXP, PNGTS entered into an arrangement with TC Energy regarding the construction of certain facilities on the TC Energy system (TransQuebec and Maritimes Pipeline (TQM) and TC Energy’s Canadian Mainline natural gas transmission system (Canadian Mainline)) that were required to fulfill PXP contracts on the PNGTS system. In the event the Canadian system expansions had terminated prior to their in-service dates, PNGTS could have been required to reimburse TC Energy for an amount up to the total outstanding costs incurred to the date of the termination. As a result of placing the TC Energy facilities associated with the Phases I, II and III volumes in service, PNGTS' reimbursement obligation to TC Energy relating to this project has been extinguished.
PNGTS' Westbrook XPress Project (Westbrook XPress) - Westbrook XPress is an estimated $125 million multi-phase expansion project that is expected to generate approximately $35 million in revenue for PNGTS on an annualized basis when fully in service. It is part of a coordinated offering to transport incremental Western Canadian Sedimentary Basin (WCSB) natural gas supplies to the Northeast U.S. and Atlantic Canada markets through additional compression capability at an existing PNGTS facility. Westbrook XPress is designed to be phased in over a four-year period which began on November 1, 2019 with Phase I. On June 18, 2020, FERC issued a certificate of public convenience and necessity for Phases II and III for this project. On January 9, 2021, construction crews and equipment were mobilized to the existing Westbrook Compressor Station following the authorization received from FERC by PNGTS on January 6, 2021. Phases II and III have estimated in-service dates of November 2021 and 2022, respectively. These three Phases will add incremental capacity of approximately 43,000 Dth/day, 69,000 Dth/day, and 18,000 Dth/day, respectively. Westbrook XPress, together with PXP, will increase PNGTS’ capacity by 90 percent from 210,000 Dth/day to approximately 400,000 Dth/day. The Westbrook XPress contracts expire between 2036 and 2042.
Iroquois Gas Transmission ExC Project - In 2019, Iroquois initiated the “Enhancement by Compression” project (Iroquois ExC Project) which will optimize the Iroquois system to meet current and future gas supply needs of utility customers while minimizing the environmental impact through enhancements at existing compressor stations along the pipeline. In February 2020, Iroquois filed an application with FERC to authorize the construction of the project. On September 30, 2020, FERC issued its Environmental Assessment (EA) for the Iroquois ExC Project. The EA concluded that approval of the project, with appropriate mitigating measures, would not constitute a major federal action significantly affecting the quality of the human environment. The
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project’s total design capacity is approximately 125,000 Dth/day with an estimated cost of $250 million and in-service date of November 2023. This project will be 100 percent underpinned with 20-year contracts.

North Baja XPress Project (North Baja XPress) - North Baja XPress is an estimated $90 million project to transport additional volumes of natural gas along North Baja’s mainline system. The project was initiated in response to market demand to provide firm transportation service of approximately 495,000 Dth/day between Ehrenberg, Arizona and Ogilby, California. The binding open season for the project was concluded in April of 2019. In December 2019, North Baja filed an application with FERC to authorize the construction of this project. On September 8, 2020, FERC issued its Environmental Assessment (EA) for the North Baja XPress Project. The EA concluded that approval of the project, with appropriate mitigating measures, would not constitute a major federal action significantly affecting the quality of the human environment. North Baja XPress was subject to a Final Investment Decision (FID) by Sempra LNG International, LLC, (Sempra LNG) regarding the development, construction and operation of a Liquified Natural Gas (LNG) terminal in Baja California, Mexico and on November 17, 2020, Sempra LNG reached a positive FID on the project. North Baja XPress has an estimated in-service date of February 2023 and is still subject to regulatory approvals and other requirements of the project.

Great Lakes Long-term Contracts Related to ANR's Alberta XPress Project - On February 12, 2020, TC Energy approved the Alberta XPress Project, an expansion project on its ANR Pipeline system with an estimated in-service date of 2022. This project utilizes existing capacity on the Great Lakes system (of which we own 46.45 percent) and TC Energy’s Canadian Mainline systems to connect growing natural gas supply from the WCSB to U.S. Gulf Coast LNG export markets. In 2018, Great Lakes entered into long-term transportation capacity contracts with ANR for approximately 900,000 Dth/day of aggregate capacity for a term of 15 years. In connection with the approval of the Alberta XPress Project, such contracts have been reduced to provide for approximately 168,000 Dth/day of aggregate capacity for a term of 20 years at maximum rates for a total contract value of $182 million starting in 2022. The contract contains reduction options (i) at any time on or before October 1, 2022 for any reason and (ii) at any time, if ANR is not able to secure the required regulatory approval related to its anticipated expansion projects. Any remaining unsubscribed capacity on Great Lakes will be available for contracting in response to developing marketing conditions. In June 2020, ANR filed an application with FERC to authorize construction of the project. On December 4, 2020, FERC issued its Environmental Assessment (EA) for the Alberta XPress Project. The EA concluded that approval of the project, with appropriate mitigating measures, would not constitute a major federal action significantly affecting the quality of the human environment. In the first quarter of 2021, Alberta XPress has been modified to reflect revised shipper commitments. ANR has not exercised its contract reduction rights as a result of the revised shipper commitments on Alberta XPress. In the event of a contract reduction, the remaining unsubscribed capacity on Great Lakes will be available for contracting.

GTN XPress Project– In March 2020, GTN filed applications with FERC to authorize the replacement of certain facilities on the GTN system. Once in service, the replacements will increase the reliability of existing transportation service including 100,000 Dth/day of existing, long-term, full-haul system capacity. In 2021, GTN will file an application with FERC for the installation of an additional compressor at a brownfield compressor site and other related work. Once in service, this work will increase GTN's long-term system capacity by an incremental 150,000 Dth/day. The estimated total project cost of this integrated reliability and expansion project is $335 million. The project’s reliability work is anticipated to be in service by the end of 2021 and will account for more than three quarters of the total project cost. These costs are expected to be recovered in recourse rates. The project’s expansion work is anticipated to be commercially phased into service through November 2023. GTN XPress’ expansion work is 100 percent underpinned by fixed rate negotiated contracts with an average term in excess of 30 years. The incremental capacity is expected to generate approximately $25 million in revenue annually when fully in service.
Laws and Regulation

2020 PIPES Act – On December 27, 2020, the Protecting Our Infrastructure of Pipelines and Enhancing Safety Act of 2020 (2020 PIPES Act) was signed into law as part of a broader federal spending and COVID-19 relief package. In addition to authorizing funding for PHMSA’s pipeline safety programs through fiscal year 2023, the 2020 PIPES Act provides several substantive amendments to the federal pipeline safety statutes, including requiring PHMSA to provide public notice of enforcement hearings and ensuring that formal hearings are open to the public, issue new rules implementing a leak detection and repair program, and determine whether to proceed with rulemaking to update class location requirements. President Biden's administration will have responsibility for implementing the 2020 PIPES Act and we are in the process of assessing impacts associated with this new legislation. See also Part I, Item 1. “Business- Government Regulation-Pipeline Safety Matters” for more information relating to PHSMA regulation of gas pipelines.

NEPA Final Rule On July 16, 2020, the Council on Environmental Quality (CEQ), under former President Trump's administration, published a final rule modifying the National Environmental Policy Act (NEPA). The modified final rule establishes a time limit of two years for preparation of environmental impact statements and one year for the preparation of environmental assessments. The modified rule also eliminates the responsibility to consider cumulative effects of a project. The final rule is being widely criticized by environmental and conservation groups and is facing court challenges. The Partnership sees these updates as positive for the industry, as CEQ streamlines the review process. However, the updated rules may be delayed due to congressional review or litigation or President Biden's Administration may direct CEQ to reconsider or withdraw the rule.
FERC's Instant Final Rule – The Natural Gas Act (NGA) allows intervening parties to file requests for rehearing with FERC within thirty days after FERC issues an order granting a certificate of public convenience and necessity and prohibits any party from appealing such a certificate order to the courts without having received a final ruling from FERC. In lieu of following the statutory requirement of thirty days to respond to a rehearing request, FERC used “tolling orders” effectively granting itself more
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time. This prevented the requester from being able to appeal the certificate to the courts, while FERC continued to grant notices to proceed with construction (NTPs) with the requests for rehearing still pending.

Intervening parties recently challenged the tolling order practice in court. Prior to the court’s decision, on June 9, 2020, FERC issued an Instant Final Rule (IFR) prohibiting it from issuing NTPs while rehearing requests are pending. On June 30, 2020, the D.C. Circuit Court of Appeals issued an opinion prohibiting FERC from utilizing tolling orders without any substantive ruling.
The IFR and the D.C. Circuit Opinion together cause concern that potential delays may occur in the certification process given that FERC will need to issue decisions on rehearing requests in a much shorter timeframe.

The Partnership believes that under the current framework, these issuances will likely have a small impact on our pending and future projects, if any at all. Many of our projects in execution are largely compression-based and involve little-to-no greenfield construction, which have tended to be less likely to draw a rehearing request. However, certain avenues still exist for FERC to extend the time period longer, FERC continues to retain discretion over when to issue a notice to proceed, and the current framework may be modified by legislation (some of which has already been proposed) or a potential further appeal to the United States Supreme Court, therefore we cannot know the impact of FERC's IFR with certainty at this time.

Environmental (Water) U.S. Army Corps of Engineers (USACE) and EPA Rulemaking: In 2020, considerable steps were taken by the USACE and EPA, under former President Trump's administration, to define the scope of waters federally regulated under the Clean Water Act (CWA), known as Waters of the United States (WOTUS), as well as the framework and implementation of CWA permitting and certification programs that Partnership projects are regulated under. For example, while constructing, maintaining, repairing, and/or replacing our pipelines and related facilities, our activities may discharge dredged or fill material into WOTUS and, in effect, may require a CWA Section 401 water quality certification and CWA Section 404 general permit, such as Nationwide Permit (NWP) 12. On June 22, 2020 a revised, narrower, definition of WOTUS, as proposed by the EPA and USACE, became effective. On September 11, 2020, EPA’s rule clarifying various aspects of the CWA Section 401 water quality certification process, became effective. The final WOTUS and Section 401 certification rules, which are both very favorable to our permitted activities and business, were subsequently challenged in federal courts, with litigation still pending.

Additionally, the CWA Section 404 NWP Program has been under increased national scrutiny since April 15, 2020, when a Montana federal District Court ruled against TC Energy’s use of an allegedly invalid NWP 12 for the performance of construction activities affecting WOTUS in Montana for its Keystone XL oil pipeline project (the Presidential Permit for which was revoked on January 20, 2021 by executive order of President Biden) and enjoined the USACE from issuing NWP 12s to authorize any and all utility projects nationwide (later narrowed to only oil and gas pipeline construction projects) until the USACE resolved the Court’s identified compliance issue. The scope of the District Court ruling, the ensuing appeal of the ruling to higher courts, and subsequent lawsuits against other pipeline projects’ use of NWP 12 on similar grounds, have created a great deal of uncertainty around the continued use of NWP 12 for projects. Additionally, rulemaking undertaken by the USACE in 2020 to reissue or renew the 2017 NWPs, which are set to expire in 2022, may have increased the uncertainty surrounding the use of NWP 12. The final rule, which reissued 12 existing NWPs, included a restructured NWP 12 that separated utilities covered under the permit into three NWPs, with the more contentious oil and gas pipelines isolated from the rest. The reissuance also did not rectify the ESA non-compliance at the center of the legal dispute in the Keystone XL NWP litigation. The USACE’s final rule will become effective in March 2021. The uncertainty surrounding NWP 12 as a result of the pending litigation and USACE may materially affect the Partnership’s business, particularly with the arrival of President Biden's administration. For further discussion on environmental matters, see Part I, Item 1 “Government Regulation” – “Environmental Matters”.

Environmental (Species) –The U.S. Fish and Wildlife Service (USFWS), under former President Trump, spent 2020 developing a rule which notably clarifies that criminal liability under the Migratory Bird Treaty Act (MBTA) will apply only to actions “directed at” migratory birds, its nests, or its eggs and not those lawful activities, such as pipeline facility construction, maintenance, repair, and related activities, which inadvertently result in the “incidental take” of migratory birds. This controversial rulemaking is beneficial to the Partnership, but if reversed by President Biden’s administration, the Partnership may continue being subject to the criminal liability associated with the "incidental take" of migratory birds, their nests, and their eggs under the MBTA, which may have a material effect on the Partnership. Additionally, former President Trump's administration also finalized two notable Endangered Species Act (ESA) rules in December 2020. One rule established a definition for “habitat” for the limited purpose of designating critical habitat and another rule which established the process and factors to be considered when determining whether to exclude certain lands from critical habitat designations, controversially including economic impacts. For further discussion on environmental matters, see Part I, Item 1 “Government Regulation” – “Environmental Matters”.

Environmental (Air) – Federal and State Climate Change Regulations –The trend towards increased regulation of GHG emissions in the oil and natural gas sector to combat climate change was evident in federal and state agency rulemaking in 2020, predominantly at the state level. On August 13, 2020, the EPA issued policy and technical amendments to lessen the administrative and compliance cost burden on the oil and gas industry related to the New Source Performance Standards (NSPS). One of the rules, imposing policy amendments and dated to be effective on September 14, 2020, notably removed the transmission and storage sector from the source category and rescinded methane and Volatile Organic Compound (VOC) requirements for remaining sources. The amendments are currently being challenged in federal court. Notwithstanding these legal challenges, President Biden issued an executive order on January 20, 2021 that specifically directed the EPA to review the technical amendments and to propose revisions to existing source standards. The more controversial policy amendment is expected to be addressed soon. Additionally, on December 27, 2020, former President Trump signed into law the 2020 PIPES Act, which includes a requirement for PHMSA to regulate methane emissions from pipelines, joining EPA as one of two federal
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regulators of GHG emissions. State and local governments are also increasingly regulating GHGs, potentially leading to additional compliance costs and operating restrictions. For example, Oregon is undertaking rulemaking to develop a carbon cap and reduce program at the direction of its Governor. Local governments in those states are also moving towards building electrification, cutting demand for hydrocarbon energy sources. For further discussion on environmental matters, see Part I, Item 1 “Government Regulation” – “Environmental Matters”.

Cash Distributions to Common Units and our General Partner
Our quarterly declared cash distributions in 2020 remained the same as in 2019, which was $0.65 per common unit or $2.60 per common unit in total for the year. Please read Note 14 within Part IV, Item 15. “Exhibits and Financial Statement Schedules” for more information.
On April 21, 2020, the TC PipeLines Board declared the Partnership'sPartnership’s first quarter 20172020 cash distribution in the amount of $0.94$0.65 per common unit, payablewhich was paid on May 15, 201712, 2020 to unitholders of record as of May 5, 2017.1, 2020. The declared distribution totaled $68$47 million and was paid in the following manner: $65$46 million to common unitholders (including $5$4 million to the General Partner as a holder of 5,797,106 common units and $11$7 million to another subsidiary of TransCanadaTC Energy as holder of 11,287,725 common units) and $3$1 million to our General Partner which included $1 million for its effective two percent general partner interest and $2 million in respect of its IDRs.

interest.

On July 20, 2017,23, 2020, the board of directors of our General PartnerTC PipeLines Board declared the Partnership'sPartnership’s second quarter 20172020 cash distribution in the amount of $1.00$0.65 per common unit, payablewhich was paid on August 11, 201714, 2020 to unitholders of record as of August 1, 2017.3, 2020. The declared distribution totaled $74$47 million and was paid in the following manner: $69$46 million to common unitholders (including $6$4 million to the General Partner as a holder of 5,797,106 common units and $11$7 million to another subsidiary of TransCanadaTC Energy as holder of 11,287,725 common units) and $5$1 million to our General

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Partner which included $2 million for its effective two percent general partner interest and $3 million in respect of its IDRs.

interest.

On October 24, 2017,21, 2020, the board of directors of our General PartnerTC PipeLines Board declared the Partnership'sPartnership’s third quarter 20172020 cash distribution in the amount of $1.00$0.65 per common unit, payablewhich was paid on November 14, 201713, 2020 to unitholders of record as of November 3, 2017.2, 2020. The declared distribution totaled $74$47 million and was paid in the following manner: $70$46 million to common unitholders (including $6$4 million to the General Partner as a holder of 5,797,106 common units and $11$7 million to another subsidiary of TransCanadaTC Energy as holder of 11,287,725 common units) and $4$1 million to our General Partner which included $1 million for its effective two percent general partner interest and $3 million in respect of its IDRs.

interest.

On January 23, 2018,19, 2021, the board of directors of our General PartnerTC PipeLines Board declared the Partnership'sPartnership’s fourth quarter 20172020 cash distribution in the amount of $1.00$0.65 per common unit, payablewhich was paid on February 13, 201812, 2020 to unitholders of record as of February 2, 2018. ThisJanuary 29, 2020. The declared distribution totaled $47 million and was paid in the following manner: $46 million to ourcommon unitholders (including $4 million to the General Partner includedas a $2holder of 5,797,106 common units and $7 million distributionto another subsidiary of TC Energy as a holder of 11,287,725 common units) and $1 million to the General Partner for its effective two percent general partner interest and an IDR payment of $3 million for a total distribution of $5 million.

interest.

Incentive distributions are paid to our General Partner if quarterly cash distributions on the common units exceed levels specified in the ThirdFourth Amended and Restated Agreement of Limited Partnership of the Partnership (as amended, the Partnership Agreement). The Partnership paid a total of $10 milliondistributions declared during 2020 did not reach the specified levels for any period and, therefore, the General Partner did not receive any distributions in respect of theits IDRs to our General Partner on the distributions declared from the first to the fourth quarter of 2017.in 2020. See Part II, Item 7 "Management's“Management’s Discussion and Analysis of Financial Condition and Results of Operations – Cash Distribution Policy of the Partnership"Partnership” for further information regarding the Partnership'sPartnership’s distributions.

Pipeline updates

To date, there has been no annual Class B distribution for 2021. In 2020, the Class B distribution paid was $8 million. Please read Note 11 within Part IV, Item 15. “Exhibits and Financial Statement Schedules” for more detailed disclosure on the Class B units.
Other Business Developments

Northern Border complaint - On March 31, 2020, BP Canada Energy Marketing Corp., Oasis Petroleum Marketing LLC and Tenaska Marketing Ventures (the Alliance for Open Markets) filed a complaint with FERC (Docket No. RP20-745-000) against Northern Border alleging that Northern Border violated Sections 4 and 5 of the NGA FERC policy, and other regulations by (i) failing to post capacity as available on a long-term basis before entering into a prearranged transaction for six agreements with ONEOK Rockies Midstream, L.L.C.; (ONEOK Midstream) and (ii) structuring the prearranged transaction open season in a manner that denied other shippers a meaningful opportunity to bid on the capacity. On April 2, 2020, ConocoPhillips Company, Shell Energy North America (US), L.P. and XTO Energy Inc. (the Indicated Shippers, together with the Alliance for Open Markets, the Complainants) filed a second complaint with FERC (Docket No. RP20-767-000) against Northern Border containing similar allegations regarding the prearranged transaction open season. The Complainants have requested that FERC (a) unwind the six prearranged contracts; (b) require Northern Border to hold an open season for the capacity such that all interested parties are on equal footing; and (c) direct Northern Border to cease from engaging in prearranged transactions where the unsubscribed capacity has not been publicly posted as generally available.

The prearranged contracts range in volume from 40,000 to 269,732 Dth/day for terms ranging from 10 months to 10 years, two of which began on June 1, 2020. Northern Border filed a motion to consolidate the two complaint dockets and filed its response to the complaints on May 1, 2020. On June 1,2020, updated tariff sheets reflecting the contract price were filed by Northern Border with FERC for the two contracts set to begin June 1, 2020. On July 1, 2020, FERC issued an order and accepted the tariff sheets, subject to the outcome of complaint proceedings.

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On October 15, 2020, FERC issued an order on the complaints and directed Northern Border to (1) refrain from making similar, discriminatory awards of capacity in the future, (2) rescind the pre-arranged deals with ONEOK Midstream, effective October 15, 2020, and (3) hold a new open season without a pre-arranged shipper. In addition, FERC directed Northern Border to file revisions to its tariff requiring it to post capacity on its website before entering a pre-arranged deal. FERC did not order Northern Border to refund any of the revenue earned from the pre-arranged transactions with ONEOK Midstream.

Northern Border held an open season from October 21 to 28, 2020 to remarket the capacity. Final bids were evaluated and the successful bids reflect a revenue that approximates Northern Border’s maximum recourse rates, a reduction from the pre-arranged contract rate.

Great Lakes Contracting501-G Proceeding - On May 11, 2020, FERC terminated Great Lakes’ 501-G proceeding and Settlement – On April 24, 2017,ruled that Great Lakes had complied with the one-time reporting requirement, designated as FERC Form No. 501-G related to the rate effect of the Tax Cuts and Jobs Act (2017 Tax Act). Additionally, FERC also stated that rate reductions provided for in Great Lakes' 2017 settlement and the 2.0% rate reduction from the Limited Section 4 Rate Reduction proceeding have provided substantial rate relief for Great Lakes’ shippers and as a result, FERC will not exercise its right to institute a NGA Section 5 investigation to determine if Great Lakes is over-recovering on its current tariff rates.

Commercial system purchase- On August 1, 2020, GTN, Great Lakes, Tuscarora and North Baja entered into a purchase agreement with a TC Energy affiliate to purchase an internally developed customer-facing commercial natural gas transmission information technology (IT) application that maintains and manages customer contracts, natural gas capacity release, customer nominations, metering and billings. The total value of the transaction was $51 million and the Partnership's proportionate share of the cost was $38 million. Prior to the transaction close, GTN, Great Lakes, Tuscarora and North Baja each paid the affiliate for the use of this system as part of their ongoing operating expenses. As a result of the capital purchase, the amount paid by each pipeline will be added to its respective rate base and utilized in the calculation of maximum allowable rates.

Iroquois' Wright Interconnect Project - During the first quarter of 2020, Iroquois received a notice of termination of its precedent agreement with Constitution pipeline related to its Wright Interconnect Project. In April 2020, Iroquois exercised its contractual right for reimbursement through a guarantee from Williams Partners, L.P., a 41 percent owner of the Constitution pipeline project. During the third quarter of 2020, the parties reached an agreement for a $48.5 million reimbursement of project costs, recovering all but $3 million of capital expenditures spent by Iroquois on the termsproject. The proceeds received by Iroquois were distributed to its partners, of which the Partnership's proportionate share was approximately $24 million. The proceeds received by the Partnership were treated as a newreturn of capital and used for general partnership purposes.

Great Lakes' Contract with TC Energy's Canadian Mainline - As noted in our 2019 Annual Report on Form 10-K for the year 2019 (2019 Annual Report), a significant portion of Great Lakes’ total contract portfolio is contracted by its affiliates including its long-term transportation capacity contractagreement with its affiliate, TransCanada. The contract, which was subject to Canada's National Energy Board (NEB) approval, isTC Energy’s Canadian Mainline (Canadian Mainline) that commenced on November 1, 2017 for a term of 10 years andten-year period that allows TransCanada the abilityTC Energy to transport up to 0.711 billion cubic feet (equivalent to about 722,000 Dth/day) of natural gas per day on the Great Lakes system from the Manitoba/U.S. border to the U.S. border near Dawn Ontario. On September 21, 2017, TransCanada received approval from the NEB and assystem. This contract contained a result, the contract commenced on November 1, 2017. The contract contains volume reduction optionsoption up to full contract quantity beginning in year three.

until November 1, 2020. During the latter half of 2017 andfourth quarter, the early part of 2018, Great Lakes sold all of its available 2017-2018 firm winter capacity. This level of contracting is significantly higher than that seen on this pipeline in recent years, and indicates a favorable shift in market dynamics for this asset.

On October 30, 2017, Great Lakes filed a rate settlement with FERC to satisfy its obligations from its 2013 rate settlement for new rates to be in effect by January 1, 2018 (2017 Great Lakes Settlement). The 2017 Great Lakes Settlement, which was approved by FERC on February 22, 2018, decreased Great Lakes' maximum transportation rates by 27 percent effective October 1, 2017. Great Lakes expects that, notwithstanding the decrease in rates, the impact from other changes, including: the recent long-term transportation contract with TransCanada as described above, other revenue opportunitiesCanadian Mainline requested an extension on the system and the elimination of the revenue sharing mechanism with its customers, will more than offset the full year impact of thevolume reduction in Great Lakes' rates beginning in 2018. The 2017 Great Lakes Settlement does not contain a moratorium provisionoption deadline and Great Lakes extended the option expiry to November 16, 2020 and then again until November 20, 2020.


On November 20, 2020, both parties came to an agreement. Effective November 1, 2021 the original contract rate will be requiredreduced with no changes in the contracted volume. Additionally, after November 20, 2020, the Canadian Mainline shall have the right to filereduce the contracted volume or terminate the full contract, effective November 1st of the applicable year, provided that 349 days’ prior written notice has been given to Great Lakes. As of February 24, 2021, no further changes to this contract have been made. The future revenue reduction on Great Lakes from the revised contract is not expected to have a material impact on the Partnership's expected distributions from Great Lakes.
Financing and Credit Ratings

GTN financing- On June 1, 2020, GTN’s $100 million 5.29 percent Senior Notes matured and were refinanced through a Note Purchase and Private Shelf Agreement whereby GTN issued $175 million of 10-year Series A Senior Notes with a fixed coupon rate of 3.12 percent per annum and entered into a three-year private shelf agreement for an additional $75 million. The new rates no later than March 31, 2022, with new ratesSeries A Senior Notes do not require any principal payments until maturity on June 1, 2030. Proceeds from the Series A Senior Note issuance were used to be effective October 1, 2022.

Northern Border Contracting – Northern Border revenues are substantially supportedrepay the outstanding balance of the 5.29 percent Senior Notes and to fund the GTN XPress capital expenditures through the balance of 2020. GTN expects to draw the remaining $75 million available under the 3-year private shelf agreement for an additional $75 million of Senior Notes (GTN Private Shelf Facility) by firm transportation contracts through the end of 2020. The continued successful renewals of these contracts provide a strong indication of Northern Border's competitive position.

GTN Incremental Contracting – GTN had successful open seasons during late 2017 and2023, the early part of 2018 generally in line with increasing available upstream capacity following the debottlenecking activities on TransCanada's pipelines. As a result, GTN has sold all its available firm capacity beginning mid-2020. GTN continues to provide a key

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transportation service delivering natural gas out of Western Canada to downstream markets in the Pacific Northwest and California.

Continent to Coast (C2C) Project – In the fourth quarter of 2017, PNGTS filed to increase its FERC-certificated capacity to accommodate the period during which the approximately 82,000 Dth/day of long-term contracts (C2C contracts) overlap with certain of its original contracts which mature in 2019. On November 28, 2017, PNGTS received the approval from FERC to increase its capacity up to approximately 210,000 Dth/day effective December 1, 2017. The C2C contracts were effective December 1, 2017 and they mature in 2032.

Portland XPress Project – PNGTS has executed precedent agreements (PAs) with several local distribution companies (LDCs) in New England and Atlantic Canada (PXP contracts) to re-contract certain system capacity set to expire in 2019 as well as construct incremental compression facilities within PNGTS' existing footprint in Maine (Portland Xpress Project or "PXP"). The PXP contracts, together with the C2C contracts, will provide transportation service of natural gas in the New England area of up to 0.3 Bcf/d by November 1, 2020, effectively utilizing all of PNGTS' expanded capacity through 2032. The in-service dates of PXP will be phased-in over a three-year period beginning November 1, 2018.

PNGTS expects the capital cost of PXP to be approximately $80 million, which PNGTS expects to finance through a new credit facility. Concurrently with PXP, TransCanada will perform upstream capacity expansions of approximately $107 million (TransCanada PXP Expenditures), the majority of which is expected to be incurred following the anticipated receipt dates of required regulatory approvals. In connection with the TransCanada expansions, PNGTS signed a precedent agreement with TransCanada that contemplates the execution of a firm transportation agreement for each of the three phases of PXP, which will be assigned to the LDCs at theestimated completion of each phase. Prior to assignment of the TransCanada transportation agreements to its customers, PNGTS is obligated for the TransCanada PXP Expenditures in the event PXP does not proceed as anticipated.

Northern Border Settlement – Northern Border's 2013 settlement agreement required Northern Border to file for new rates no later than January 1, 2018. On December 4, 2017, Northern Border filed a rate settlement with FERC which precluded the need to file a general rate case by January 1, 2018 (2017 Northern Border Settlement). The 2017 Northern Border Settlement, which was approved by FERC on February 23, 2018, provides for tiered rate reductions effective January 1, 2018, with no change to the underlying rate design. The 2017 Northern Border Settlement does not contain any moratorium and unless superseded by a subsequent rate case or settlement, recourse rates in effect at December 31, 2017, will decrease by 5.0% on January 1, 2018; by an additional 5.5% on April 1, 2018; and by a further 2.0% beginning January 1, 2020 through December 31, 2023, when Northern Border will be required to establish new rates. This equates to an overall rate reduction of 12.5% by January 1, 2020 from the recourse rates in effect at December 31, 2017.

Acquisitions and Financing

Debt Offering – On May 25, 2017, the Partnership closed a $500 million public offering of senior unsecured notes bearing an interest rate of 3.90 percent maturing May 25, 2027. The net proceeds of $497 million were used to fund a portion of the 2017 Acquisition.

2017 Acquisition – On June 1, 2017, the Partnership completed the acquisition of a 49.34 percent interest in Iroquois from subsidiaries of TransCanada and an option to acquire a further 0.66 percent interest in Iroquois, together with an additional 11.81 percent interest in PNGTS that results in the Partnership owning a 61.71 percent interest in PNGTS. The total purchase price of the 2017 Acquisition was $765 million plus final purchase price adjustments amounting to approximately $50 million. The purchase price consisted of: (i) $710 million for the Iroquois interest (less $164 million, which reflected the Partnership's 49.34 percent share of Iroquois' outstanding debt at the time of the 2017 Acquisition); (ii) $55 million for the additional 11.81 percent interest in PNGTS (less $5 million, which reflected our 11.81 percent share in PNGTS' outstanding debt at the time of the 2017 Acquisition); (iii) final working capital adjustments for Iroquois and PNGTS amounting to $19 million and $3 million, respectively; and (iv) additional consideration of $28 million for the surplus cash (discussed below) on Iroquois' balance sheet. The Partnership funded the cash portion

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of the 2017 Acquisition through a combination of proceeds from the May 25, 2017 public debt offering and borrowing under its Senior Credit Facility.

As of the date of the 2017 Acquisition, there was significant cash on Iroquois' balance sheet. Pursuant to the Purchase and SaleGTN XPress Project. The GTN Private Shelf Agreement associated with the acquisition of the Iroquois interest, as amended, the Partnership agreed to pay $28 million plus interest to TransCanada on August 1, 2017 for its 49.34 percent share of the cash determined to be surplus to Iroquois' operating needs.

Iroquois' partners adopted a distribution resolution to address the surplus cash on Iroquois' balance sheet post-closing. The Partnership expects to receive the $28 million of unrestricted cash as part of its quarterly distributions from Iroquois over 11 quarters under the terms of the resolution, which began with Iroquois' second quarter 2017 distribution on August 1, 2017. As of February 26, 2018 the Partnership has received approximately $7.8 million of the expected $28 million, of which $5.2 million was received in 2017 and $2.6 million was received on February 1, 2018.

Tuscarora Refinancing – On August 21, 2017, Tuscarora refinanced all of its outstanding debt by amending its existing Unsecured Term Loan Facility and issuing a new $25 million variable rate term loan that will require yearly principal payments beginning September 1, 2018 and will mature on August 21, 2020. Tuscarora's Unsecured Term Loan contains a covenant that requires Tuscaroralimits total debt to maintain a debt service coverage ratio (cash available from operations divided by the sum of interest expense and principal payments) ofno greater than or equal to 3.00 to 1.00. As65 percent of December 31, 2017, the ratio was 11.09 to 1.00.

2013GTN’s total capitalization.


Tuscarora financing- On July 23, 2020, Tuscarora's $23 million Unsecured Term Loan Facility – On September 29, 2017, the Partnership's variable rate $500 million Term loan facility that was due on July 1, 2018August 21, 2020 was amended to extend the maturity period throughdate to August 20, 2021 under generally the same terms.

PNGTS financing- On October 2, 2022. As8, 2020, PNGTS entered into a resultNote Purchase and Private Shelf Agreement whereby PNGTS issued $125 million of this extension,10-year Series A Senior Notes with a coupon of 2.84% per annum and entered into a three-year private shelf agreement for an additional $125 million Senior Notes. The PNGTS Series A Notes do not require any principal payments
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until maturity on October 8, 2030. Proceeds from the Partnership implementedSeries A Senior Note issuance were used to repay the outstanding balance of PNGTS' revolving credit facility and for general partnership purposes including funding of growth capital. PNGTS expects to draw the remaining $125 million available under the 3-year private shelf agreement for an interest rate hedging strategy duringadditional $125 million of Senior Notes (PNGTS Private Shelf Facility) by the fourthend of third quarter of 2021 to refinance amounts funded on its revolving credit facility for costs associated with the Westbrook XPress Project. The PNGTS Private Shelf Facility contains a covenant that limits total debt to no greater than 65 percent of PNGTS’ total capitalization and hedgedrequires PNGTS to maintain a leverage ratio of no greater than 5.00 to 1.00.
GTN credit rating affirmation-On January 21, 2021, Moody's Investors Service (Moody's) affirmed GTN's A3 credit rating and revised GTN's outlook to stable from negative primarily in connection with the entire $500 million untilrevision of TC Energy's outlook to stable from negative.
Great Lakes' credit rating upgrade- On June 21, 2020, Standard & Poor's (S&P) upgraded Great Lakes' credit rating by two notches from BBB-/Stable to BBB+/Stable primarily due to an improvement in Great Lakes' financial risk profile resulting from its October 2, 2022 maturity using forward starting swaps atincreased long-term contracting levels.

PNGTS credit rating upgrade- On July 24, 2020, Fitch upgraded PNGTS' credit rating by one notch from BBB/Stable to BBB+/Stable primarily due to an average rate of 3.26 percent. At December 31, 2017, the 2013 $500 million Term loan facility was hedged by fixed interest rate swap arrangements at an effective interest rate of 2.31 percent, expiring Julyimprovement in PNGTS' financial risk profile resulting from placing is PXP Phase II Project in-service on November 1, 2018.

2015 Term Loan Facility2019.


Northern Border credit rating upgradeOn September 29, 2017,3, 2020, S&P affirmed Northern Border’s credit rating at BBB+ and upgraded the outlook from Stable to Positive based on strong recontracting, continued stable cash flows, conservative leverage, solid shipper base and strong sponsors.

Credit rating affirmation- On September 30, 2020, S&P affirmed the Partnership's $170 million Term loan facility that was due on October 1, 2018 was amendedBBB/Stable credit rating. S&P continues to extendconsider the maturity period through October 1, 2020.

2017 US Tax Reform – On December 22, 2017,Partnership's business risk profile to be a key strength underpinned by its highly contracted, long-term, take-or-pay contracts with creditworthy counterparties. S&P further recognizes the President ofPartnership's strong basin diversification and benefits associated with its strategic relationship with TC Energy despite the United States signed into law H.R. 1 (the "Tax Cuts and Jobs Act" or the "2017 Tax Act"). The 2017 Tax Act resulted in major changes to U.S. tax law, including a decrease in the U.S. corporate federal tax rate from 35 percent to 21 percent effective January 1, 2018. Although we are not a federally taxable entity, we expect the lower tax rates to impact future rate-setting processes on our pipeline systemsexpected higher leverage due to the FERC-regulated naturefunding of our business.its growth projects. On October 30, 2020, Moody's also affirmed the Partnership's credit rating at Baa2/Stable.


On October 6, 2020 S&P revised the Partnership's outlook from Stable to Creditwatch Positive in connection with TC Energy's offer to acquire the Partnership's outstanding common units. The FERC approves our pipelines' rates on a cost-of-service basis which includes a recovery of our ultimate taxable owners' income tax expense as a componentCreditwatch reflects S&P's opinion that TC Energy's offer to acquire all of the rates chargedoutstanding units will increase the level of parental support from TC Energy. Tuscarora was also placed on Creditwatch Positive.
$350 million Senior Notes redemption-The Partnership's $350 million aggregate principal amount of 4.65 percent Unsecured Senior Notes mature on June 15, 2021. On February 12, 2021, the Partnership exercised its option to customers. Over time, we expect these changes will impact our future performance through changes inredeem the Unsecured Senior Notes on March 15, 2021 at a redemption price equal to 100% of the principal amount of the notes then outstanding, plus unpaid interest accrued to March 15, 2021. Partial funding for the redemption is expected to be provided using cash flows generated by our subsidiarieson hand, and distributions from our equity investments.

Please refer also to Note 4borrowings under the Partnership's consolidated financial statements included in Part IV within Item 15. "Exhibits and Financial Statement Schedules" and Part II- Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations-Critical Accounting Estimates for more information.)

Partnership’s $500 million Senior Credit Facility.

Business Strategies

Our strategy is focused on generating long-term, steady and predictable distributions to investour unitholders by investing in long-life critical energy infrastructure that provides reliable transportationdelivery of energy to customers.

Our investment approach is to develop or acquire assets that provide stable cash distributions and opportunities for new capital additions, while maintaining a low-risk profile. We are opportunistic and disciplined in our approach when identifying new investments.

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Our goal is to maximize distributable cash flows over the long-term through efficient utilization of our pipeline systems and appropriate business strategies, while maintaining a commitment to safe and reliable operations.

Understanding the Natural Gas PipelineInfrastructure Business

Natural gas pipelines moveinfrastructure moves natural gas from major sources of supply or upstream pipelinesgathering facilities to downstream pipelines or locations or markets that use natural gas to meet their energy needs. PipelineInfrastructure systems include meter stations that record how much natural gas comes on to the pipeline and how much exits at the delivery locations; compressor stations that act like pumps to move the large volumes of natural gas along the pipeline; and the pipelines themselves that transport natural gas under high pressure.

Regulation, rates and cost recovery

Interstate natural gas pipelines are regulated by FERC. FERC approves the construction of new pipeline facilities and regulates aspects of our business including the maximum rates that are allowed to be charged. Maximum rates are based on operating costs, which include allowances for operating and maintenance costs, income and property taxes, interest on debt, depreciation expense to recover invested capital and a return on the capital invested. During 2018, FERC issued a revised policy statement that changed its long-standing policy on the treatment of income taxes for rate-making purposes for MLP-owned pipelines. The revised policy statement had a significant impact on MLPs in general and on their respective natural gas pipeline assets. (See also Part I, Item 1. “Business- Government Regulation- 2018 FERC Actions for” more information).
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Although FERC regulates maximum rates for services, interstate natural gas pipelines frequently face competition and therefore may choose to discount their services in order to compete.

Because FERC rate reviews are periodic and not annual, actual revenues and costs typically vary from those projected during a rate case. If revenues no longer provide a reasonable opportunity to recover costs, a pipeline can file with FERC for a determination of new rates, subject to any moratoriums in effect. FERC also has the authority to initiate a review to determine whether a pipeline'spipeline’s rates of return are just and reasonable. SometimesIn some cases, a settlement or agreement with the pipelinepipeline’s shippers is achieved, precluding the need for FERC to conduct a rate case, which may include mutually beneficial performance incentives. A settlement is ultimately subject to FERC approval.

Contracting

New pipelineinfrastructure projects are typically supported by long-term contracts. The term of the contracts is dependent on the individual developer'sdeveloper’s appetite for risk and is a function of expected rates of return, stability and certainty of returns. Transportation contracts expire at varying times and underpin varying amounts of capacity. As existing contracts approach their expiration dates, efforts are made to extend and/or renew the contracts. If market conditions are not favorable at the time of renewal, transportation capacity may remain uncontracted, be contracted at lower rates or be contracted on a shorter-term basis. Unsold capacity may be recontracted if and when market conditions become more favorable. The ability to extend and/or renew expiring contracts and the terms of such subsequent contracts will depend upon the overall commercial environment for natural gas transportation and consumption in the region in which the pipeline is situated.

Business environment

The North American natural gas pipelineinfrastructure network has been developed to connect supply basins to market. Use and growth of this infrastructure isthe systems are affected by changes in the location, relative cost of natural gas supply and changing market demand.

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The map below shows the location of certain North American basins in relation to our pipeline systems together with those of our General Partner TransCanada Corporation.

and TC Energy.


tcp-20201231_g1.jpg

Supply

Natural gas is primarily transported from producing regions and, in limited circumstances, from liquefied natural gas (LNG) import facilities to market hubs or interconnects for distribution to natural gas consumers. The ongoing development of shale and other unconventional gas reserves has resulted in increases in overall North American natural gas production and economically recoverable reserves.

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There has been an increase in production from the development of shale gas reserves that are located close to traditional markets, particularly in the Northeastern U.S. This has increased the number of supply choices for natural gas consumers and has contributed to the decline of higher-cost sources of supply (such as certain offshore gas production from Atlantic Canada) resulting in changes to historical natural gas pipeline flow patterns.

The supply of natural gas in North America is expected to continue increasing significantly over the next decade and over the long-term for a number of reasons, including the following:

use of technology, including horizontal drilling in combination with multi-stage hydraulic fracturing, is allowing companies to access unconventional resources economically. This is increasing the technically accessible resource base of existing and emerging gas basins; and

application of these technologies to existing oil fields where further recovery of the existing resource is now possible. There is often associated natural gas discovered in the exploration and production of liquids-rich hydrocarbons (for example the Bakken oil fields), which also contributes to an increase in the overall natural gas supply for North America.

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Other factors that can influence the overall level of natural gas supply in North America include:

the price of natural gas – low prices in North America may increase demand but reduce drilling activities that in turn diminish production levels, particularly in dry natural gas fields where the extra revenue generated from the associated liquids is not available. High natural gas prices may encourage higher drilling activities but may decrease the level of demand;

producer portfolio diversification – large producers often diversify their portfolios by developing several basins, but this is influenced by actual costs to develop the resource as well as economic access to markets and cost of pipeline transportation services. Basin-on-basin competition impacts the extent and timing of a resource development that, in turn, drives changing dynamics for pipeline capacity demand; and

regulatory and public scrutiny – changes in regulations that apply to natural gas production and consumption could impact the cost and pace of development of natural gas in North America.

Demand

The natural gas pipeline business ultimately depends on a shipper'sshipper’s demand for pipeline capacity and the price paid for that capacity. Demand for pipeline capacity is influenced by, among other things, supply and market competition, economic activity, weather conditions, natural gas pipeline and storage competition and the price of alternative fuels.

The growing supply of natural gas has resulted in relatively low natural gas prices in North America which has supported increased demand for natural gas particularly in the following areas:

natural gas-fired power generation;

petrochemical and industrial facilities;

the production of Alberta'sthe Marcellus, Alberta’s oil sands, and the Bakken and shale deposits, although new greenfield projects that have not begun construction may be delayed in the current oil price environment;

exports to Mexico to fuel electric power generation facilities; and

exports from North America to global markets through a number of proposed LNG export facilities.

Commodity Prices

In general, the profitability of the natural gas pipelines business is not directly tied to commodity prices given we are a transporter of the commodity and the transportation costs are not tied to the price of natural gas. However, the cyclical supply and demand nature of commodities and its price impact can have a secondary impact on our business where our shippers may choose to accelerate or delay certain projects. This can impact the timing for the demand of transportation services and/or new gas pipeline infrastructure.

Competition

Competition among natural gas pipelines is based primarily on transportation rates and proximity to natural gas supply areas and consuming markets. Changes in supply locations and regional demand have resulted in changes to pipeline flow dynamics. Where pipelines historically transported natural gas from one or two supply sources to their markets under long-term contracts, today many pipelines transport gas in multiple directions and under shorter contract terms. Some pipelines have even reversed their flows in order to adapt to changing sources of supply. Competition among pipelines to attract supply and new or existing markets to their systems has also increased across North America.

Our Pipeline Systems

Natural Gas Infrastructure

We have ownership interests in eight natural gas interstate pipeline systems that are collectively designed to transport approximately 10.411.3 billion cubic feet per day of natural gas from producing regions and import facilities to market hubs and consuming markets primarily in the Western, Midwestern and Eastern U.S. All of our pipeline systems, except Iroquois and the pipeline facilities jointly owned with Maritimes and Northeast Pipeline LLC (MNE) on PNGTS joint facilities,(Joint Facilities), are operated by
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subsidiaries of TransCanada.TC Energy. The Iroquois pipeline system is operated by Iroquois Pipeline Operating Company, a wholly owned subsidiary of Iroquois. The PNGTS Joint Facilities (see below) are operated by MNOC, M&N Operating Company, LLC (MNOC),a subsidiary of MNE. MNE is a subsidiary of Enbridge Inc.

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Our pipeline systems include:






PipelineLengthDescriptionOwnership

Pipeline
LengthDescriptionOwnership
Gas Transmission Northwest LLC (GTN)GTN1,377 milesExtends betweenfrom an interconnection near Kingsgate, British Columbia, Canada at the Canadian border to a point near Malin, Oregon at the California border and delivers natural gas to the Pacific Northwest and to California.100 percent
Bison Pipeline LLC (Bison)303 milesExtends from a location near Gillette, Wyoming to Northern Border'sBorder’s pipeline system in North Dakota. Bison can transport natural gas from the Powder River Basin to Midwest markets.100 percent
North Baja Pipeline, LLC (North Baja)86 milesExtends betweenfrom an interconnection with the El Paso Natural Gas Company pipeline near Ehrenberg, Arizona andto an interconnection with a natural gas pipeline near Ogilby, California on the Mexican border transporting natural gas in the southwest. North Baja is a bi-directional pipeline.100 percent
Tuscarora Gas Transmission Company (Tuscarora)305 milesExtends betweenfrom the terminus of the GTN pipeline near Malin, Oregon to its terminus near Reno, Nevada and delivers natural gas in northeastern California and northwestern Nevada.100 percent
Northern Border Pipeline Company (Northern Border)1,412 milesExtends betweenfrom the Canadian border near Port of Morgan, Montana to a terminus near North Hayden, Indiana, south of Chicago. Northern Border is capable of receiving natural gas from Canada, the Bakken, the Williston Basin and the Rocky Mountain area for deliveries to the Midwest. ONEOK Partners, L.P.Northern Border Pipeline Company Holdings LLC owns the remaining 50 percent of Northern Border.50 percent
Portland Natural Gas Transmission System (PNGTS)PNGTS295 milesConnects with the TQM pipeline at the Canadian border to deliver natural gas to customers in the U.S. northeast. Northern New England Investment Company, Inc. owns the remaining 38.29 percent of PNGTS. The 295-mile pipeline includes 107 miles of jointly owned pipeline facilities (the Joint Facilities) with Maritimes and Northeast Pipeline LLC (MNE).MNE. The Joint Facilities extend from Westbrook, Maine to Dracut, Massachusetts and PNGTS owns approximately 32%32 percent of the undivided ownership interest based on contractually agreed upon percentages.Joint Facilities.61.71 percent(a)
Great Lakes Gas Transmission Limited Partnership (Great Lakes)2,115 milesConnects with the TransCanadaTC Energy Mainline at the Canadian border points near Emerson, Manitoba, Canada and St. Clair, Michigan, near Detroit. Great Lakes is a bi-directional pipeline that can receive and deliver natural gas at multiple points along its system. TransCanadaTC Energy owns the remaining 53.55 percent of Great Lakes.46.45 percent
Iroquois Gas Transmission System, L.P (Iroquois)416 milesExtends from the TransCanadaTC Energy Mainline system near Waddington, New York to deliver natural gas to customers in the U.S. northeast. The remaining 50.66 percent is owned by TransCanadaby: TC Energy (0.66 percent), Dominion Midstream (25.93Berkshire Hathaway Energy (Berkshire Hathaway) (50 percent) and Dominion Resources (24.07 percent).49.34 percent(b)
(a)
On June 1, 2017, the Partnership acquired an additional 11.81 percent interest from TransCanada resulting in 61.71 percent ownership in PNGTS. (Refer to Note 7 of the Partnership's consolidated financial statements included in Part IV within Item 15. "Exhibits and Financial Statement Schedules")

(b)
Effective June 1, 2017 (Refer to Note 7 of the Partnership's consolidated financial statements included in Part IV within Item 15. "Exhibits and Financial Statement Schedules")

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The map below shows the location of our pipeline systems.

tcp-20201231_g2.jpg

Customers, Contracting and Demand

Our customers are generally large utilities, LDCs,Local Distribution Companies (LDCs), major natural gas marketers, producing companies and other interstate pipelines, including affiliates. Our pipelinessystems generate revenue by charging rates for transporting natural gas. Natural gas transportation service is provided pursuant to long-term and short-term contracts on a firm or interruptible basis. The majority of our pipeline systems' natural gas transportation services are provided through firm service transportation contracts with a reservation or demand charge that reserves pipeline capacity, regardless of use, for the term of the contract. The revenues associated with capacity reserved under firm service transportation contracts are not subject to
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fluctuations caused by changing supply and demand conditions, competition or customers. Customers with interruptible service transportation agreements may utilize available capacity after firm service transportation requests are satisfied.

Our pipeline systems actively market their available capacity and work closely with customers, including natural gas producers, LDCs, marketers and end users, to ensure our pipelines are offering attractive services and competitive rates. Approximately 74 percent of our long-term contract revenues are with customers who have an investment grade rating or who have provided guarantees from investment grade parties. We have obtained financial assurances as permitted by FERC and our tariffs for the remaining long-term contracts. See Part I, Item 1A. "Risk“Risk Factors."

One

Transactions with our major customers that are at least 10 percent of our consolidated revenues can be found under Note 16-Transactions with major customers Anadarko Energy Services Company accounted forwithin Part IV, Item 15. “Exhibits and Financial Statement Schedules," which information is incorporated herein by reference. Additionally, our equity investee Great Lakes earns a significant portion of ourits revenue from TC Energy and comprised 11 percent of the Partnership's revenues in 2017.

its affiliates as disclosed under Note 17-Related party transactions within Part IV, Item 15. “Exhibits and Financial Statement Schedules,” which information is incorporated herein by reference.

GTN – GTN'sGTN’s revenues are substantially supported by long-term contracts through the end of 2023 with its remaining contracts extending between 2024 and 2045. These contracts, which have historically been renewed on a long-term

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basis upon expiration, are primarily held by residential and commercial LDCs and power generators that use a diversified portfolio of transportation options to serve their long-term markets and marketers contracting under a variety of contract terms. A portion of GTN's contract portfolio is contracted by industrial shippers and producers. We expect GTN to continue to be an important transportation component of these diversified portfolios. Incremental transportation opportunities are based on the difference in value between Western Canadian natural gas supplies and deliveries to Northern California.

Currently, GTN is benefitting from an increase in the volumes of natural gas it transports as

Upstream debottlenecking activities occur on upstream pipeline systemsTC Energy's NGTL System, which deliverdelivers natural gas to GTN. These upstream activities are continuing and as a result, we are in the process of signingGTN, has allowed GTN to sign over 700,000 Dth/day in long-term contracts of which 348,000 Dth/day will result in additional volumes flowing onto GTN as early as mid-2018 with the remainder from 2019 toin-service dates between 2018 and 2020. The majority of these contracts have terms of at least 15 years.


During the fourth quarter of 2019, we announced the GTN XPress Project, the largest organic growth opportunity in the Partnership's 20-year history. This project includes a horsepower replacement program and a brownfield expansion. The reliability work will enable increased firm natural gas transportation on GTN, which together with the growth component of the project, will sum to 250,000 Dth/d in additional long-term contracts on the pipeline system. See Part I, Item 1. “Business- Recent Business Developments-Growth Projects Update” for more information.
In early 2019, GTN’s largest customer, Pacific Gas and Electric Company (Pacific Gas), filed for Chapter 11 bankruptcy protection. On July 1, 2020, Pacific Gas emerged from its bankruptcy proceedings. Pacific Gas accounted for approximately seven percent of the Partnership’s consolidated revenues in 2020 (2019 - seven percent). As a utility company, Pacific Gas serves residential and industrial customers in the state of California and has an ongoing obligation to serve its customers. We have not experienced collection issues to date and expect this to continue going forward.
Northern Border – Northern Border is a highly competitive pipeline system and is fully contracted with its revenues substantially supported by firm transportationa weighted average remaining contract length of approximately 5 years. Northern Border contracts through the end of 2020. Northern Border's contractsthat include renewal rights and expiring contracts have typically been renewed for terms of five years. A significant portion of Northern Border’s contract portfolio is contracted by utilities, marketers and industrial load. In addition, Northern Border sells seasonal transportation services which have traditionally been strongest during peak winter months to serve heating demand and peak spring/summer months to serve electric cooling demand and storage injection.

Great Lakes – Great Lakes' revenue is derived from both short-haul and long-haul transportation services. The majority of its contracts are with TransCanadaTC Energy and affiliates on multiple paths across its system. Great Lakes' ability to sell its available and future capacity will depend on future market conditions which are impacted by a number of factors including weather, levels of natural gas in storage, the capacity of upstream and downstream pipelines and the availability and pricing of natural gas supplies. Demand for Great Lakes' services has historically been highest in the summer to fill the natural gas storage complexes in Ontario and Michigan in advance of the upcoming winter season. During the winter, Great Lakes serves peak heating requirements for customers in Minnesota, Wisconsin, Michigan and the upper Midwest of the U.S. During the latter half
A significant portion of 2017 and the early part of 2018, Great Lakes sold all ofLakes’ total contract portfolio is contracted by its available 2017-2018 firm winter capacity. This level of contracting is significantly higher than that seen on this pipeline in recent years, indicative of a favorable shift in market dynamics for Great Lakes.

During 2017, Great Lakes benefited from TransCanada's new long-term fixed price service onaffiliates including its Canadian Mainline. Concurrent with the launch of this new service, Great Lakes entered into a long-term transportation agreement with TransCanada'sTC Energy’s Canadian Mainline for 0.711 billion of cubic feet that commenced on November 1, 2017 for a ten-year period and contains volume reduction optionsthat allows TC Energy to transport up to fullabout 0.711 billion cubic feet of natural gas per day on the Great Lakes system. This contract quantity beginningwas a direct benefit from TC Energy’s long-term fixed price service on its Canadian Mainline that was launched in year three. This2017. TC Energy’s long-term fixed price service provides long-term capacity to TransCanada'sTC Energy’s shippers for the transportation of WCSB natural gas to markets in Eastern Canada and the U.S.

See Part I, Item 1. “Business- Recent Business Developments-Other Business Developments” for more information.


In early 2020, TC Energy approved the Alberta XPress Project, an expansion project on its ANR Pipeline system with an estimated in-service date of 2022. This project utilizes existing aggregate capacity on Great Lakes System of approximately 168,000 Dth/day for a term of 20 years at maximum rates for a total contract value of $182 million starting in 2022.
This contract, which has a full quantity reduction option at any time before October 1, 2022, is dependent on ANR's ability to secure the required regulatory approvals and other requirements of the project associated with these volumes. See Part I, Item 1. “Business- Recent Business Developments- Growth Projects Update” for more information.

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PNGTSPNGTS'PNGTS’ revenues are primarily generated from transportation agreements with LDCs throughout New England.England and Canada’s Atlantic provinces. The majority of PNGTS'PNGTS’ current revenue stream is supported by long-term contracts.contracts entered into via a series of open seasons for long-term capacity held by PNGTS in recent years. Long-term contractcontracts with several shippers involving commitments of approximately 82,000 Dth/day from thePNGTS’ Continent-to-Coast Contracts for a term of 15 years (the C2C open seasonContracts) began December 1, 2017, necessitating an increase in PNGTS'PNGTS’ certificated capacity up to approximately 210,000 Dth/day. The C2C contractsContracts mature in 2032 and replaced some expiring short-term and long-term contracts.

2032.

In addition to the C2C contracts,Contracts, in 2017, as a result of its PXP open season, PNGTS executed 20-year PAsprecedent agreements with several LDCs in New England and Atlantic Canada to re-contract certain system capacity set to expire in 2019 as well as expand the PNGTS system to bring its certificated capacity up tosystem. PXP Phases I, II and III were placed into service during the fourth quarter of 2018, 2019 and 2020, respectively. The total final volume of the project is approximately 0.3 Bcf/183,000 Dth/day: 40,000 Dth/day by November 1, 2020, effectively utilizing allfrom Phase I, 118,400 Dth/day from Phase II, which includes re-contracting and renewal of PNGTS' expanded capacity through 2032.

PXP will proceed concurrently with upstream capacity expansions on the Trans Quebec & Maritimes Pipeline (TQM)expiring contracts, and TransCanada's Canadian Mainline systems. The in-service dates of PXP are being phased-in over a three-year period beginning November 1, 2018.24,600 Dth/day from Phase III. PXP, together with the C2C expansion brings additional, natural gas supply options to markets in New England and Atlantic Canada in response to the growing need for natural gas transportation capacity in the region.

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PXP is fully subscribed with no uncontracted firm capacity to meet incremental market demand in this region. In response, PNGTS developed a second expansion project. In early 2019, PNGTS announced the Westbrook XPress Project which is an independent project that is designed to be phased in over a four-year period beginning November 1, 2019 with Phase I. Phases II and III have estimated in-service dates of November 2021 and 2022, respectively. Westbrook XPress will add incremental capacity for Phases I, II and III of approximately 43,000 Dth/day, 69,000 Dth/day, and 18,000 Dth/day, respectively. Westbrook XPress, together with PXP, will increase PNGTS’ capacity by 90 percent from 210,000 Dth/day to approximately 400,000 Dth/day. The Westbrook XPress contracts expire between 2036 and 2042. See Part I, Item 1. “Business- Recent Business Developments-Growth Projects Update” for more information about PXP and Westbrook XPress.
Iroquois – Iroquois transports natural gas under long-term contracts that expire between 20182021 and 20262032 and extends from TransCanada'sTC Energy’s Canadian Mainline system at the U.S. border near Waddington, New York to markets in the U.S. northeast, including New York City, Long Island and Connecticut. Iroquois provides service to local gas distribution companies, electric utilities and electric power generators, as well as marketers and other end users, directly or indirectly, through interconnecting pipelines and exchanges throughout the northeastern U.S. Iroquois also earns discretionary transportation service revenues which can have a significant earnings impact. Discretionary transportation service revenues include short-term firm transportation service contracts with less than one-year terms as well as standard interruptible transportation service contracts. In 2017,2020, Iroquois earned approximately 1112 percent of its revenues from discretionary services.

Bison

During the second quarter of 2019, Iroquois initiated the ExC Project to meet current and future gas supply needs of utility customers by upgrading its compressor stations along the pipeline. This project will be 100 percent underpinned with 20-year contracts and is subject to the receipt of necessary permits and approvals. This project has an estimated in-service date of November 2023. See Part I, Item 1. “Business- Recent Business Developments-Growth Projects Update” for more information.
North BajaNaturalThe North Baja pipeline system is an 86-mile bi-directional natural gas pipeline transporting gas between Arizona, California and the Mexican border since 2002. North Baja’s historical steady financial performance is due to its strong contracting levels, having a weighted average remaining firm contract length of about 7 years. North Baja currently has a design capacity of 500 mcf/d of southbound transportation and is capable of transporting 600 mcf/d in a northbound direction.
In April 2019, we concluded a successful binding open season for North Baja XPress Project to transport approximately 495,000 Dth/day of additional volumes of natural gas along North Baja’s mainline system between Arizona and California. The estimated in-service date of the project is February 2023, subject to regulatory approvals and other requirements of the project. See Part I, Item 1. “Business- Recent Business Developments-Growth Projects Update” for more information.
Bison – As previously disclosed, natural gas is currently not flowing on the Bison system in response to the recent relative cost advantage of WCSB-WCSB and Bakken -sourcedsourced gas versus Rockies production. From its in-service date in 2011 up to the fourth quarter of 2018, Bison has not experienced a decrease in its revenue as it iswas fully contracted on a ship-or-pay basisbasis. During the fourth quarter of 2018, through a Permanent Capacity Release Agreement, Tenaska Marketing Ventures (Tenaska) assumed Anadarko Energy Services Company’s (Anadarko) ship-or-pay contract obligation on Bison, the largest contract on Bison. After assuming the transportation obligation, Bison accepted an offer from Tenaska to terminate this contract. Following the amendment of its tariff to enable this transaction, another customer executed a similar agreement to terminate its contract on Bison. At the completion of the contracts, Bison was released from performing any future services with the two customers and as such, the amounts received were recorded in revenue in 2018.
The two customers represented approximately 60 percent of Bison’s revenue in 2018 and accordingly, in 2019 and 2020, Bison’s revenue was reduced by approximately $47 million and $49 million, respectively, in comparison to 2018 revenues when Bison was fully contracted. Its remaining contracts in the system expire in January 2021.
Based on this development and other qualitative factors, the Partnership evaluated the remaining carrying value of 2021.

Other PipelinesBison’s property, plant and equipment at December 31, 2018 and concluded that the entire amount was no longer recoverable, resulting in a non-cash impairment charge during the fourth quarter of 2018. We continue to explore alternative transportation-related options for Bison and we believe commercial potential exists to allow natural gas transported on Bison to flow in both directions, with the southwest direction involving deliveries onto third party pipelines and ultimately connecting into the Cheyenne hub. In any event, Bison will continue to incur costs related to property tax and operating and maintenance costs of approximately $6 million per year. See also Part II, Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations - Critical Accounting Estimates” for more information.

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TuscaroraNorth Baja and TuscaroraTuscarora’s revenues are substantially supported by long-term contracts with a weighted average remaining contract length of approximately 5 years. We expect Tuscarora to continue be fully contracted on a long-term basis when its current contracts expire.
During the fourth quarter of 2019, we announced that we are proceeding with the Tuscarora XPress Project, which is an estimated $13 million expansion project through 2020additional compression capability at an existing Tuscarora facility. Tuscarora XPress is 100 percent underpinned by a 20-year contract and beyond.

will transport approximately 15,000 Dth/day of additional volumes when completed in November 2021. Tuscarora XPress is expected to generate approximately $2 million in revenue on an annualized basis when fully in service.


Competition

Overall, our pipeline systems generate a substantial portion of their cash flow from long-term firm contracts for transportation services and are therefore insulated from competitive factors during the terms of the contracts. If these long-term contracts are not renewed at their expiration, our pipeline systems face competitive pressures which influence contract renewals and rates charged for transportation services.

GTN and Northern Border, through their respective connections with TransCanada's FoothillTC Energy's Foothills systems, and Great Lakes and Iroquois, through their respective connections with TransCanada'sTC Energy's Canadian Mainline, compete with each other for WCSB natural gas supply as well as with other pipelines, including the Alliance pipeline and the Westcoast pipeline. Northern Border and Great Lakes compete in their respective market areas for natural gas supplies from other basins as well, such as the Bakken, Rocky Mountain area, Mid-Continent, Gulf Coast, Utica and Marcellus basins. GTN primarily competes with pipelines supplying natural gas into California and Pacific Northwest markets.

Bison competes for deliveries with other pipelines that transport natural gas supplies within and away from the Rocky Mountain area.

area, and gas from the Rocky Mountains that is delivered into the Midwest must compete with gas sourced from the Bakken and Western Canada.

North Baja'sBaja’s southbound pipeline capacity competes with deliveries of LNG received at the Costa Azul terminal in Mexico. WhenIf LNG shipments are received at Costa Azul, North Baja'sBaja’s northbound capacity competes with pipelines that deliver Rocky Mountain area, Permian and San Juan basin natural gas into the Southernsouthern California area.

Tuscarora competes for deliveries primarily into the northern Nevada natural gas market with natural gas from the Rocky Mountain area.

PNGTS connects with the TQM pipeline at the Canadian border and shares facilities with the MNE from Westbrook, Maine to a connection with the Tennessee Gas Pipeline System near Boston, Massachusetts. PNGTS competes with LNG supplies and gas flows from Canada and with LNG delivered into Boston. Tennessee Gas Pipeline and Algonquin Gas Transmission also compete with PNGTS for gas deliveries into New England markets.

As noted above, Iroquois, through its connection with TransCanada'sTC Energy’s Canadian Mainline System, competes for WCSB natural gas supply with other pipelines. Iroquois connects at five locations with three interstate pipelines (Tennessee Gas, CNG Gas Transmission and Algonquin Gas Transmission) and TransCanada'sTC Energy’s Canadian Mainline System near Waddington, New York and provides a link between WCSB natural gas deliveries to markets in the states of Connecticut, Massachusetts, New Hampshire, New Jersey, New York, and Rhode Island.

Additionally, our pipeline assets face competition from other pipeline companies seeking opportunities to invest in greenfield natural gas pipeline development opportunities. This competition could result in fewer projects being

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available that meet our pipeline systems'systems’ investment hurdles or projects that proceed with lower overall financial returns.

Relationship with TransCanada

TransCanadaTC Energy

TC Energy is the indirect parent of our General Partner and at December 31, 2017,2020, owns, through its subsidiaries, approximately 24.224 percent of our common units, 100 percent of our Class B units, 100 percent of our IDRs and an effectivehas a two percent general partner interest in us. TransCanadaTC Energy is a major energy infrastructure company, listed on the Toronto Stock Exchange and NYSE, with more than 65 years of experience in the responsible development and reliable operation of energy infrastructure in North America. TransCanada'sTC Energy’s business is primarily focused on natural gas and oilliquids transmission and power generation services. TransCanadaservices, delivering the energy millions of people rely on to power their lives in a sustainable way. TC Energy consists of investments in 57,100approximately 58,000 miles of natural gas pipelines, approximately 3,000 miles of wholly-owned oilliquids pipelines and 653535 billion cubic feet of natural gas storage capacity. TransCanadaTC Energy also owns or has interests in over 6,100approximately 4,200 megawatts of power generation.

TransCanada TC Energy operates most of our pipeline systems and, in some cases, contracts for pipeline capacity. We have purchased assets from TransCanada and jointly participated with TransCanada in acquiring assets from third parties, including acquisitions that we would have been unable to pursue on our own. TransCanada views


On December 14, 2020 the Partnership, as a core element of its strategythe General Partner, TC Energy, TC Northern, TC PipeLine USA, and considersMerger Sub, entered into the dropdown of assetsTC Energy Merger Agreement. Pursuant to the TC Energy Merger Agreement, Merger Sub will be merged with and into the Partnership, with the Partnership continuing as the sole surviving entity and an indirect, wholly owned subsidiary of TC Energy.

Subject to the terms and conditions set forth in the TC Energy Merger Agreement, at the effective financing option as it executestime of the TC Energy Merger, each common unit representing a fractional part of the limited partner interests in the Partnership issued and outstanding immediately prior to the effective time of the TC Energy Merger, other than common units owned by TC Energy and its capital growth program, subject to actual funding needs and market conditions. There can be no assurance as to when and on what terms these assets affiliates,
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will be offered to the Partnership.cancelled in exchange for 0.70 shares of TC Energy common shares. See also Part III,I, Item 13. "Certain Relationships and Related Transactions, and Director Independence"1. “Business- Recent Business Developments - Planned Merger with TC Energy" for more information on our relationshipMerger Agreement with TransCanada.

TC Energy.

Government Regulation

Federal Energy Regulatory Commission

All of our pipeline systems are regulated by FERC under the Natural Gas Act of 1938 (NGA)NGA and Energy Policy Act of 2005, which gives FERC jurisdiction to regulate virtuallyeffectively all aspects of our business, including:

transportation of natural gas in interstate commerce;

rates and charges;

terms of service and service contracts with customers, including counterparty credit support requirements;

certification and construction of new facilities;

extension or abandonment of service and facilities;

accounts and records;

depreciation and amortization policies;

acquisition and disposition of facilities;

initiation and discontinuation of services; and

standards of conduct for business relations with certain affiliates.

Our pipeline systems'systems’ operating revenues are determined based on rate options stated in our tariffs which are approved by FERC. Tariffs specify the general terms and conditions for pipeline transportation service including the rates that may be charged. FERC, either through hearing a rate case or as a result of approving a negotiated rate settlement, approves the maximum rates permissible for transportation service on a pipeline system which are designed to recover the pipeline'spipeline’s cost-based investment, operating expenses and a reasonable return for its investors. Once maximum rates are set, a pipeline system is not permitted to adjust the maximum rates to reflect changes in costs or contract demand until new rates are approved by FERC. Pipelines are permitted to charge rates lower than the maximum tariff rates in order to

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compete. As a result, earnings and cash flows of each pipeline system depend on a number of factors including costs incurred, contracted capacity and transportation path, the volume of natural gas transported, and rates charged.

Regulatory

2018 FERC Actions
Background:
During the latter part of 2018, the Partnership completed its regulatory filings to address the issues contemplated by Public Law No. 115-97, commonly known as the 2017 Tax Act and Rate Proceedings

certain FERC actions that began in March of 2018, namely FERC’s Revised Policy Statement on Treatment of Income Taxes (Revised Policy Statement) and a Final Rule that established a schedule by which interstate pipelines must either (i) file a new uncontested rate settlement or (ii) file a one-time report, called FERC Form No. 501-G, that quantified the rate impact of the 2017 Tax Act on FERC-regulated pipelines and the impact of the Revised Policy Statement on pipelines held by MLPs (collectively, the 2018 FERC Actions).

Impact of the 2018 FERC Actions to the Partnership:
The 2018 FERC Actions directly addressed two components of our pipeline systems’ cost-of-service based rates: the allowance for income taxes and the inclusion of ADIT in their rate base. The 2018 FERC Actions also noted that precise treatment of entities with more ambiguous ownership structures must be separately resolved on a case-by-case basis, such as those partially owned by corporations including Great Lakes, Northern Border, Iroquois and PNGTS. Additionally, any FERC-mandated rate reduction did not affect negotiated rate contracts. Prior to the 2018 FERC Actions, none of the Partnership’s pipeline systems had a requirement to file or adjust their rates earlier than 2022 as a result of their existing rate settlements. However, several of our pipeline systems accelerated such adjustments as a result of the 2018 FERC Actions. The resulting impact from the actions taken by our pipelines to address the 2018 FERC Actions requirements are outlined below:
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2018 FERC Actions Impact on Maximum RatesMoratorium, Mandatory
Filing Requirements and
Other Considerations
Great Lakes2.0% rate reduction effective February 1, 2019No moratorium in effect; comeback provision with new rates to be effective by October 1, 2022
GTNA refund of $10 million to its firm customers in 2018; 10.0% rate reduction effective January 1, 2019; additional rate reduction of 6.6% effective January 1, 2020 through December 31, 2021; these reductions will replace the 8.3% rate reduction in 2020 agreed to as part of the last settlement in 2015Moratorium on rate changes until December 31, 2021; comeback provision with new rates to be effective by January 1, 2022; Settlement agreement reflected an elimination of income tax allowance and ADIT
Northern Border2.0% rate reduction effective February 1, 2019 to December 31, 2019 extended until July 1, 2024 unless superseded by a subsequent rate case or settlementNo moratorium in effect; comeback provision with new rates to be effective by July 1, 2024
BisonNo rate changes proposedNo moratorium or comeback provisions
Iroquois3.25% rate reduction effective March 1, 2019; additional 3.25% rate reduction effective April 1, 2020Moratorium on rate changes until September 1, 2020; comeback provision with new rates to be effective by March 1, 2023
PNGTSNo rate changesNo moratorium or comeback provisions
North Baja10.8% rate reduction effective December 1, 2018No moratorium or comeback provisions; approximately 90 percent of North Baja’s contracts are negotiated; 10.8% reduction is on maximum rate contracts only
Tuscarora1.7% rate reduction effective February 1, 2019; additional rate reduction of 10.8% effective August 1, 2019Moratorium on rate changes until January 31, 2023; comeback provision with new rates to be effective by February 1, 2023; Settlement agreement reflected an elimination of income tax allowance and ADIT
The Final Rule allowed pipelines owned by MLPs and other pass through entities to remove the ADIT liability from their rate bases, and thus increase the net recoverable rate base, partially or in some cases wholly mitigated the loss of the tax allowance in cost-of-service based rates. Following the elimination of the tax allowance and the ADIT liability from rate base, rate settlements and related filings of all pipelines held wholly or in part by the Partnership summarized above, the estimated impact of the tax-related changes to our revenue and cash flow is a reduction of approximately $30 million per year on an annualized basis beginning in 2019.
In 2019 and 2020, the estimated impact of the tax-related changes to our revenue and cashflow have been largely mitigated by additional revenue generated from continued strong natural gas flows mainly out of WCSB and from solid contracting levels across the Partnership pipeline assets. See Part II, Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations” for more information.
Existing rate settlements:
GTN On October 16, 2018, GTN operates underfiled an uncontested settlement with FERC to address the changes proposed by the 2018 FERC Actions on its rates established pursuantvia an amendment to its prior 2015 settlement (the 2018 GTN Settlement). The 2018 GTN Settlement reflects an elimination of the tax allowance previously recovered in rates along with ADIT for rate-making purposes (see details of the 2018 GTN Settlement in the table above).
Tuscarora On March 15, 2019, Tuscarora filed an uncontested settlement with FERC to address the issues contemplated by the 2017 Tax Act and 2018 FERC Actions via an amendment to its prior 2016 settlement (the 2019 Tuscarora Settlement).
Among the terms of the 2019 Tuscarora Settlement, Tuscarora agreed to reduce its existing maximum system rates by 1.7 percent effective February 1, 2019 through to July 31, 2019, followed by an additional decrease of 10.8 percent for the period August 1, 2019 through the term of the settlement. Tuscarora is required to have new rates in effect on February 1, 2023. Tuscarora and its customers also agreed on a settlementmoratorium on rate changes until January 31, 2023. The 2019 Tuscarora Settlement, which was approved by FERC on May 2, 2019, will also reflect an elimination of the tax allowance previously recovered in June 2015. Effective Julyrates along with ADIT for rate-making purposes.
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Iroquois – On February 28, 2019, Iroquois filed an uncontested settlement with FERC to address the issues contemplated by the 2017 Tax Act and 2018 FERC Actions via an amendment to its prior 2016 settlement (the 2019 Iroquois Settlement). Among the terms of the 2019 Iroquois Settlement, Iroquois agreed to reduce its existing maximum system rates by 6.5 percent to be implemented in two phases, (i) effective March 1, 2015,2019, a 3.25 percent rate reduction and (ii) effective April 1, 2020, an additional 3.25 percent rate reduction, which will conclude the rates were reducedtotal 6.5 percent rate reduction from the 2016 settlement rates. The 2019 Iroquois Settlement, which was approved by three percent. In JanuaryFERC on May 2, 2019, preserved the 2016 GTN's rates decreased by asettlement moratorium on further 10 percent and will continue in effect through December 31, 2019.rate changes until September 1, 2020. Unless superseded by a subsequent rate case or settlement, GTN's rates will decrease an additional eight percent for the period January 1, 2020 through December 31, 2021 when GTNIroquois will be required to establishhave new rates.

rates in effect by March 1, 2023.

Great Lakes On October 30,Great Lakes operates under a settlement approved by FERC effective January 1, 2018 (the 2017 Great Lakes filed a rate settlement with FERC to satisfy its obligations from its 2013 rate settlement for new rates to be in effect by January 1, 2018.Settlement). The 2017 Great Lakes Settlement which wasdid not contain a moratorium and eliminated its revenue sharing mechanism with customers. Great Lakes is required to file new rates effective October 1, 2022. Effective February 1, 2019, FERC approved an additional 2 percent rate reduction and elimination of its tax allowance and ADIT liability from rate base pursuant to Great Lakes’ limited NGA Section 4 filing. The removal of ADIT increased net recoverable rate base and mitigated the loss of Great Lakes’ tax allowance.
Northern Border Northern Border operates under a settlement approved by FERC on February 22, 2018, decreased Great Lakes' maximum transportation rates by 27 percent effective October 1, 2017. The 2017 Great Lakes Settlement does not contain any moratorium and Great Lakes will be required to file for new rates no later than March 31, 2022, with new rates to be effective October 1, 2022.

Northern Border – Northern Border's 2013 settlement agreement required Northern Border to file for new rates no later than January 1, 2018. On December 4, 2017, Northern Border filed a rate settlement with FERC precluding the need to file a general rate case by January 1, 2018 (2017(the 2017 Northern Border Settlement). The 2017 Northern Border Settlement which was approved by FERC on February 23, 2018, providesprovided for tiered rate reductions beginningfrom January 1, 2018 with no change to the underlyingDecember 31, 2019 that equate to an overall rate design.reduction of 12.5 percent when compared to 2017 rates by January 1, 2020 (10.5 percent by December 31, 2019 and additional two percent by January 1, 2020). The 2017 Northern Border Settlement doesdid not contain a moratorium provision and Northern Border is required to file new rates effective July 1, 2024. Effective February 1, 2019, FERC approved an additional two percent rate reduction and elimination of its tax allowance and ADIT liability from rate base pursuant to Northern Border’s limited NGA Section 4 filing. On April 4, 2019, Northern Border filed an amended settlement agreement that extended the two percent rate reduction implemented on February 1, 2019 to July 1, 2024 effective January 1, 2020 unless superseded by a subsequent rate case or settlement. On May 24, 2019, FERC approved the amended settlement recourse rates in effect at December 31, 2017, will decrease by 5.0% on January 1, 2018; by an additional 5.5% on April 1, 2018;agreement and by an additional 2.0% beginning January 1, 2020 through December 31, 2023, when Northern Border will be required to establish new rates. This equates to an overallBorder’s 501-G proceeding was terminated. The removal of ADIT increased net recoverable rate reductionbase and mitigated the loss of 12.5% by January 1, 2020 from the recourse rates in effect at December 31, 2017.

Bison – Northern Border’s tax allowance.

Bison continues to operateBison operates under the rates approved by FERC in connection with Bison's initial construction and has no requirement to file a new rate proceeding.

North Baja – 

North Baja continues to operateNorth Baja operates under the rates approved by FERC in its original certificate proceeding in 2001 and has no requirement to file a new rate proceeding. On January 6, 2017, North Baja notified FERC that current market conditions do not support the replacement of the compression that was temporarily abandoned in 2013 and requested authorization to permanently abandon two compressor units and a nominal volume of unsubscribed firm capacity.Effective December 1, 2019, FERC approved the permanent abandonment request on February 16, 2017. The requested abandonments will not have any impact on existing firm transportation service.

Tuscarora – Tuscarora operates under rates establisheda 10.8 percent rate reduction and elimination of its tax allowance and ADIT liability from rate base pursuant to a settlement approved by FERC in September 2016. UnderNorth Baja’s limited NGA Section 4 filing. The removal of ADIT increased net recoverable rate base and partially mitigated the settlement, Tuscarora's system-wide unit rate initially decreased by 17 percent, effective August 1, 2016. Unless superseded by a subsequent rate case or settlement, this rate will remain in effect until July 31, 2019, after which time the unit rate will decrease by an additional seven percent from August 1, 2019 through July 31, 2022. The settlement does not contain a rate moratorium provision and requires Tuscarora to file to establish new rates no later than August 1, 2022.

loss of North Baja’s tax allowance.

PNGTS PNGTS continues to operateoperates under the rates approved by FERC in PNGTS'PNGTS’ most recent rate proceeding, effective December 1, 2010. PNGTS has no requirement to file a new rate proceeding.

Iroquois – Iroquois operates under


Policy Statement on Return on Equity

FERC issued a Policy Statement on May 21, 2020, regarding the determination of the return on equity (ROE) to be used in designing natural gas and oil pipeline rates. In the Policy Statement, FERC determined that its analysis of the ROE component of a pipeline’s rates established pursuantshould be determined by averaging the results of the Discounted Cash Flow model and the Capital Asset Pricing Model. FERC determined that it will not use the Risk Premium Model. Our pipelines are subject to a settlement approvedrate regulation by FERC and any future rate cases we file are subject to the determinations in October 2016. Under the settlement, Iroquois rates decreased ratably during the phase-in period from September 2016 through 2018 with an overall reduction of approximately 20 percent beginning September 2018. The settlement also containsthis Policy Statement. We do not expect changes in this policy to affect us in a rate moratorium until September 1, 2020. Unless superseded by a subsequent rate case or settlement, Iroquois will be required to establish new rates no latermaterially different manner than September 1, 2022.

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The 2017 Tax Act and FERC's Income Tax Recovery Inquiry

On December 22, 2017, the President ofother similarly sized natural gas pipeline companies operating in the United States signed into law the Tax Cuts and Jobs Act. This legislation provides for major changes to U.S. tax law with the most significant change being the reduction of the corporate federal income tax rate from 35 percent to 21 percent. As mentioned in the section Narrative Description of Business – General and Note 2 of the Partnership's consolidated financial statements included in Part IV within Item 15. "Exhibits and FinancialStates.


NOI on Certificate Policy Statement Schedules", we are a non-taxable master limited partnership, and income taxes owed as a result of our earnings are the responsibility of our partners. However, all of our pipeline systems are regulated by the FERC, which approves the systems' rates on a cost-of-service basis and includes a recovery of our ultimate taxable owners' income tax expense as a nominal component of the maximum allowable rates that may be charged to customers. Ultimate rates charged to customers are typically reached through negotiation without ascribing specific elements of costs of service such as income taxes.

In December 2016,


FERC issued a Notice of Inquiry Regarding the Commission'son April 19, 2018 (Certificate Policy for RecoveryStatement NOI), thereby initiating a review of Income Tax Costs (Docket No. PL17-1-000) requesting Initial Comments regarding how to address any double recovery resulting from FERC's current income tax allowance and rate of return policies that are in effect since 2005.

Docket No. PL17-1-000 is a direct response toUnited Airlines, Inc., et al. v. FERC, a decision issued by the U.S. Court of Appeals for the District of Columbia Circuit in July 2016 in which the D.C. Circuit directed FERC to explain how a pass-through entity such as a master limited partnership receiving a tax allowance and a return on equity derived from the discounted cash flow (DCF) methodology did not result in double recovery of taxes.

Various comments have been received by FERC and most recently, comments on how the 2017 Tax Act will affect the income tax recovery allowed on regulated pipelines.

There is not likely to be a definitive resolution of these issues for some time. The ultimate outcome of Docket No. PL17-1-000 is not certain and could result in changes going forward to FERC's treatment of income tax allowances in the cost of service or to the discounted cash flow return on equity. Depending upon the resolution of these issues, the cost of service rates of any of our interstate natural gas pipelines could be affected to the extent the pipeline proposes new rates or changes to its existing rates or if its rates are subject to complaint or challenged by FERC which would ultimately impact our future operating performance.

Review of FERC Natural Gas Pipelines Policy

The current FERC Chairman announced in December 2017 that FERC will review its policies on certification of natural gas pipelines, including an examination of its long-standing Policy Statement on Certification of New Interstate Natural Gas Pipeline Facilities, issued in 1999, that is used to determine whether to grant certificates for new pipeline projects. We are unable to predict what, if any, changes may be proposed as a result of the Certificate Policy Statement NOI that will affect our natural gas pipeline business or when such proposals, if any, might become effective. No further action has occurred since the Certificate Policy Statement NOI was issued. We do not expect that any changechanges in this policy wouldto affect us in a materially different manner than any other similarly sized natural gas pipeline entitycompanies operating in the United States.

Environmental

Matters


Our pipelinesassets are subject to a variety of stringent and complexU.S. federal, tribal, state and local environmental laws and regulations governing environmental protection, includingrelating to air emissions,quality, biodiversity, wastewater discharges, waste management, water management, and water quality. SuchThese laws and regulations generally require natural gas pipelinespipeline companies to obtain and comply with a wide variety of environmental registrations,
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licenses, permits and other approvalsauthorizations required for construction and operations. Certain violationsConsequences of noncompliance with these laws, regulations, or authorizations include, but are not limited to, the following: administrative, civil, and/or criminal penalties; imposition of investigatory, remedial, and/or corrective actions; delay in obtaining necessary authorizations; denial or termination of project authorizations; imposition of restrictions or limitations on project authorizations; addition or removal of conditions or terms in project authorizations; and/or the issuance of orders limiting or prohibiting operations or construction. Violations of certain environmental laws and regulations can result in the imposition of strict, joint and several liability. Failure to comply with these laws
Federal Environmental Laws and regulations may result in the assessment of sanctions, including administrative, civil and/or criminal penalties, the imposition of investigatory, remedial and corrective action requirements, the occurrence of delays or restrictions in the permitting or performance of projects and/or the issuance of orders limiting or prohibiting operations in affected areas.

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The following is a discussion of some of the applicableRegulations

Federal environmental laws, and their related regulations, each as amended from time to time, that relate tomost significantly impact our business.

pipeline operations include:
Thethe Clean Air Act (CAA) – The CAA and comparable state laws regulate emissions, which regulates air pollution on a national level by restricting the emission of air pollutants from various industrialstationary and mobile sources including compressor stations, and impose variousimposes an array of pre-construction, operational, monitoring, and reporting requirements. The CAA authorizes the EPA to adopt climate change regulatory initiatives relating to greenhouse gas (GHG) emissions;
the Federal Water Pollution Control Act, also known as the Clean Water Act (CWA), which regulates discharges of pollutants from facilities into state and in some cases, control requirements. Such lawsfederal waters and regulations may require pre-approval forestablishes the construction or modification of certain facilities expectedextent to produce air pollutants or result in an increase of existing air pollutants. Such facilities must also comply with air permits containing various emission and operational limitations, or requiring the use of emission control or abatement technologies, which could result in the imposition of substantial costs on our operations.

The Endangered Species Act (ESA) – The ESA restricts activities that may affect endangered or threatened species or their habitats. The presence of threatened or endangered species, including the designation of previously unidentified or threatened species, could cause us to incur additional costs or become subject to operating restrictions or bans in the affected areas.

Solid Wastes and Hazardous Substance and Wastes Statutes – The operations of our pipeline systemswaterways are subject to federal jurisdiction and analogous state statutes that regulaterulemaking as protected “Waters of the handling, management, storageUnited States” (WOTUS);
the Oil Pollution Act of 1990 (OPA), which subjects owners and disposaloperators of solid wastes, including hazardous wastesvessels, onshore facilities, and hazardous substances. These include the Resource Conservationpipelines, as well as lessees or permittees of areas in which offshore facilities are located, to liability for removal costs and Recovery Act the Solid Waste Disposal Act and damages arising from an oil spill in WOTUS;
the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA), which imposes liability on generators, transporters, disposers and arrangers of hazardous substances at sites where hazardous substance releases have occurred or are threatening to occur;
the federal levelResource Conservation and comparable state statutes. These statutes subject our operations to rigorous waste managementRecovery Act (RCRA), which governs the generation, treatment, storage, transport, and disposal practices to ensure compliance. In addition, of solid wastes, including hazardous wastes;
the improper disposal or a release of wastes or hazardous substance could result in the imposition of investigatory or remedial obligations.

Toxic Substances Control Act (TSCA) – The TSCA addresses, which governs the production, importation, use and disposal of specific chemicals and provides the EPA with authority to require reporting, record-keeping and testing requirements, and restrictions relating to chemical substances and mixtures. These includemixtures, including polychlorinated biphenyls (PCBs), asbestos, radon, and lead-based paint.

paint;
The Clean Waterthe Emergency Planning and Community Right-to-Know Act (CWA)(EPCRA), which requires facilities to implement a safety hazard communication program and disseminate information to employees, local emergency planning committees, and response departments on toxic chemical uses and inventories;
the Oil PollutionEndangered Species Act of 1990 (OPA) – The CWA, OPA(ESA), which restricts activities that may affect federally identified endangered and comparable state laws impose strict controls with respect to the discharge of pollutants, including spills and leaks of oil and other substances, intothreatened species or adjacent to state waters and waters of the U.S. The discharge of pollutants into regulated waters is generally prohibited, except in accordance with the terms of a permit issuedtheir habitats by the EPAimplementation of operating restrictions or a delegated statetemporary, seasonal, or federal agency. The CWApermanent ban in affected areas; and federal regulations also prohibit
the discharge of dredge and fill material into regulated waters, including wetlands, unless authorized by an appropriately issued permit. The EPA and the U.S. Army Corps of Engineers (Corps) released a final rule in May 2015 that attempted to clarify federal jurisdiction under the CWA over waters of the U.S. This interpretation by the EPA may constitute an expansion of federal jurisdiction over waters of the U.S. Implementation of the rule has been stayed nationwide, and in January 2017, the U.S. Supreme Court accepted review of the rule to determine whether jurisdiction over the challenge to the rule rests with the federal district or appellate courts. In February 2017, President Trump issued an executive order directing the EPA and the Corps to review and, consistent with applicable law, initiate a rulemaking to rescind or revise the rule. The EPA and the Corps proposed in June 2017 to repeal the June 2015 rule, announced their intent to issue a new rule defining the CWA's jurisdiction, and published a proposed rule in November 2017 that would stay implementation of the June 2015 rule for two years. The Supreme Court ruled in January 2018 that jurisdiction to decide challenges to the rule rests with federal district courts. Consequently, while implementation of the 2015 rule remains stayed, the previously-filed district court cases challenging the scope of rule will be allowed to proceed. As a result of these developments, future implementation of the June 2015 rule is uncertain at this time, but to the extent that this rule or any subsequent replacement rule expands the scope of the CWA's jurisdiction, pipeline construction and expansion projects could face increased costs and delays with respect to obtaining permits for dredge and fill activities in wetland areas.

National Environmental Policy Act (NEPA) – Natural gas transportation activities over federally-managed land or involving federal approval can be subject to review under NEPA, or analogous state requirements. NEPAwhich requires federal agencies including the Department of the Interior or FERC, to evaluate governmentalthe environmental effects of major agency actions having the potential to significantly impact the environment. In the course of such evaluations, an agency willand prepare an

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Regional, State, Tribal, and Local Environmental Laws and Regulations

In addition to the numerous environmental laws and regulations at the federal level, there exist regional, state, tribal, and local environmental laws and regulations that sometimes make permitting, development, or expansion of certain projects more extensive and complex. For example, some of our pipeline systems, as well as any proposed plansprojects may require the acquisition of permits from more than one level of government. Additionally, regional, state, tribal, or local laws and regulations may be more stringent than their federal counterparts. The existence of environmental laws at various levels of government also provide more opportunities for future activities, on federal lands are subjectcitizens’ suits or other forms of opposition to new developmental projects or the requirementsexpansion of NEPA in connection with any new approval that is required for construction, operation or use on or of federal lands. NEPA reviews can take a significant amount of time and are subject to challenge and appeal by environmental groups, who have frequently used the NEPA process to challenge pipeline construction projects over the past several years, and therefore,existing projects. These factors all have the potential to substantially restrict or delay currentproject permitting, development, or expansion of projects and future naturalincrease costs to gas transportation activities.

National Historic Preservation Act (NHPA) – The NHPA restricts activities that may affect culturalpipeline companies, including the Partnership, in the process.

Judicial Decisions, Enforcement Policies, Executive Actions

In addition to the adoption and historic resources through the implementation of procedural protections that require identificationfederal and protection of cultural and historic resources of national, state tribal and local significance. The presence of cultural and historic resources, including the designation of previously unidentified resources or sites have the potential to delay current and future natural gas transportation activities.

We have not incurred and do not anticipate incurring material costs to comply with existing environmental laws and regulations, judicial decisions interpreting those laws and regulations, enforcement policies as well as the issuance of executive actions at all levels of government can also significantly increase operational or compliance costs for gas pipeline companies. Uncertainty surrounding the interpretation of certain laws and regulations due to conflicting rulings on environmental issues in a given court system may be an added burden on operations and compliance-related decision-making.


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Notably, President Biden issued several executive orders on his first day in office on January 20, 2021, including an Executive Order (EO) for Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis. The EO directs agencies to review agency actions promulgated, issued, or adopted between January 20, 2017 and January 20, 2021, for consistency with the public health and environmental protection policy goals of the EO. If inconsistent, the EO directs agencies to consider suspending, revising, or rescinding the agency actions. Several federal environmental regulations of interest to our business, and which are discussed in this section, are subject to review under the EO, including the Navigable Waters Protection Rule and air/GHG emissions regulations. WeSpecifically, the EO directed EPA to review its recent methane technical amendment to the NSPS for stationary sources and to propose revisions to existing source standards by September 2021.

The new Administration’s chief of staff also issued a memorandum regarding a Regulatory Freeze Pending Review on January 20, 2021, to the heads of executive departments and agencies. Notably, the regulatory freeze asks department and agency heads to consider postponing the effective date of rules which have already been published in the Federal Register, and subsequently opening a comment period and reconsidering the rule as needed. The USACE’s reissuance of the NWPs and the USFWS’s new MBTA rule are subject to reconsideration under this memorandum.

Notable Water-Related Environmental Developments Potentially Impacting the Partnership

While constructing, maintaining, repairing, and/or replacing pipelines and related facilities, there may be a discharge of pollutants and/or dredged or fill material into WOTUS. Such activities are regulated under the CWA and may require special authorization from the EPA, USACE and/or States such as a CWA Section 401 water quality certification, CWA Section 402 National Pollutant Discharge Elimination System (NPDES) permit, and/or a CWA Section 404 permit for discharge of dredge or fill material, such as Nationwide Permit (NWP) 12.In 2020, the CWA was in the national spotlight with numerous high-profile regulatory actions and litigation related to the definition of WOTUS (the scope of waters federally regulated under the CWA), CWA Section 404’s NWP program, and the CWA Section 401 water quality certification process. The reversal in whole or in part of any of these regulatory actions may have a material impact on the Partnership’s business through, for example, increased compliance-related costs, project permitting delays, and more.

The Navigable Waters Protection Rule, issued under former President Trump’s administration and the most recent regulation defining the scope of waters under CWA jurisdiction, WOTUS, became effective on June 22, 2020. This rule replaces the 2015 Clean Water Rule issued under former President Obama’s administration by narrowing the definition of WOTUS and significantly reducing the number of federally regulated bodies of water. The expansion and narrowing of the definition of WOTUS has been a controversial and longstanding issue. A narrowing of the definition is favorable for the pipeline industry since it reduces the number of pipeline projects subject to burdensome and costly CWA regulation and permitting programs by limiting affected waters subject to protection under the CWA. This rule is currently being challenged in high profile cases in federal courts throughout the country. While the new rule is favorable to our industry, it’s tenure may be curtailed if there are successful court challenges and President Biden's administration, with its robust environmental protection agenda, chooses to again expand the definition of WOTUS through rulemaking.

While constructing, maintaining, repairing, and/or replacing our pipelines and related facilities, our activities may discharge dredged or fill material into WOTUS and, in effect, may require a USACE CWA Section 404 individual or general permit. NWPs are general permits issued by USACE to streamline the authorization of activities that result in no more than minimal individual and cumulative adverse environmental effects. If the environmental impact is not accruedminimal, the regulated community may need to apply for anythe more time-consuming and burdensome individual permits that evaluate discharge activities on a case-by-case basis. Historically, NWP 12 has been specifically used by utilities, including oil and gas pipelines, telecommunications lines, sewage lines, water lines, and more. The CWA Section 404 NWP Program has been under the national spotlight since April 15, 2020, when a Montana federal District Court ruled against TC Energy’s use of an allegedly invalid NWP 12 for its Keystone XL project and enjoining the USACE from issuing NWP 12s for utility activities nationwide. The Court believed the USACE violated the ESA when it renewed NWP 12 in 2017 and remanded NWP 12 back to the USACE to remedy the identified issue. The U.S. Supreme Court granted an emergency stay of the district court’s order, except as it applied to Keystone XL, while the decision’s merits were being appealed in the Ninth Circuit Court of Appeals by the federal defendants. This ongoing litigation has created tremendous uncertainty within the pipeline industry regarding the scope of pipeline activities still allowed to use NWP 12 and concern over the potential material, long-term harms to pipeline projects throughout the country if the appeal of the district court’s order in the Ninth Circuit is unsuccessful. In response to the uncertainty, many pipeline companies, including ourselves, had to reconsider permitting strategies for projects that were depending on the use of NWP 12. For example, companies have incurred additional costs and project delays by switching to alternative nationwide permits or the significantly more time-consuming individual permits. In some cases, companies have had to assume some risk in continuing to use NWP 12, particularly for those projects already in the construction phase. Other pipeline companies have also been challenged in federal courts throughout the country on similar NWP 12 grounds, indicating an increasing litigation risk to the Partnership’s continued use of NWP 12, and potentially other NWPs.

After the Keystone XL NWP 12 District Court decision, the USACE began rulemaking to reissue or renew the 2017 NWPs, including NWP 12, which are set to expire in 2022. On January 13, 2021, a final rule was published reissuing and modifying 12 of the existing NWPs, including NWP 12, and issuing four new NWPs. The rulemaking notably did not remedy the District Court’s identified ESA non-compliance that was central to the legal dispute. The reissuance also included a restructured NWP 12 that separated utilities covered under the permit into three NWPs, with the more contentious oil and gas pipelines isolated from the rest.
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The rule is effective March 15, 2021. Under President Biden's administration, the NWP reissuance rulemaking and the underlying issues in the Keystone XL NWP 12 litigation may be reconsidered in an unfavorable manner to the oil and gas pipeline industry. Additionally, the NWP reissuance may be subject to the regulatory freeze pending the review described in the Biden Administration’s January 20, 2021 memorandum. With uncertainty surrounding the use of NWP 12 for pipeline projects nationwide, particularly growth projects, the Partnership may be materially affected by experiencing project permitting delays and increased vulnerability to lawsuits. However, TC Energy continues to explore creative permitting strategies to minimize and mitigate the additional risks posed by the current regulatory uncertainty.

Furthermore, the EPA’s final rule amending regulations implementing Section 401 of the CWA, which requires states and/or authorized tribes to grant, deny, or waive a water quality certification for major federal licenses and permits, became effective on September 11, 2020. The new rule clarifies various aspects of the current Section 401 regulations, and notably narrows the scope of state and tribal review to preclude them from considering issues other than water quality in their certifications of permits and to curtail delays in decision-making. This rule is very beneficial for the permitting of our pipeline projects but is another such rule that, as expected, is being challenged heavily in court. It is imperative that the Section 401 certification process not cause additional uncertainty and delays that may cause additional material compliance costs to the Partnership and make execution of our various projects more difficult. The success of this final rule is important for our business and is something that will continue to be monitored so that the extent of the impacts to our business can be better understood.

Notable Species-Related Environmental Developments Potentially Impacting the Partnership – Environment (Species)

In 2020, the USFWS developed a rule which notably clarifies that criminal liability under the MBTA will apply only to actions “directed at” migratory birds, its nests, or its eggs and not lawful activities, such as pipeline facility construction, maintenance, repair, and related activities, which inadvertently result in the “incidental take” of migratory birds. This controversial rulemaking is very beneficial to pipeline companies, including the Partnership, since it reduces regulatory burdens, pipeline construction complications and obstacles, and mitigates criminal liability from construction activities which unintentionally impact migratory birds. The rule was finalized in December 2020 and will be effective February 8, 2021. However, it is one of the agency actions that may be subject to the regulatory freeze pending the review described in President Biden's Administration’s January 20, 2021 memorandum. The Partnership may be materially affected if the administration reverts back to the original interpretation that incidental take is not free of liability, in addition to expanding the lists of protected threatened and endangered wildlife and plants under the ESA. Additionally, in December 2020, former President Trump's administration finalized two noteworthy ESA rules. In one rule, the USFWS and NMFS established a definition for “habitat” for the sole purpose of designating critical habitat. In another rule, the USFWS identified several factors that may be considered when determining whether to exclude certain lands from critical habitat designations, including economic impacts. The latter rule allows an area to be excluded from critical habitat designation if the benefits of exclusion outweigh the benefits of inclusion for that area (as long as the exclusion does not cause species extinction). While this rule is favorable to industry, particularly pipeline companies, it is also expected to be reconsidered by President Biden's administration.

Notable Air-Related Environmental Developments Potentially Impacting the Partnership

Federal and State non-GHG Air Pollutant Regulations

In 2020, the EPA, under former President Trump's administration proposed and promulgated several air-related rules under the federal CAA that were met with significant opposition from environmental liabilities.

advocacy groups as well as state and local governments. For example, the EPA made the controversial decision in 2020 to retain, without revision the National Ambient Air Quality Standards (NAAQS) for ground level Ozone and Particulate Matter, that were established in 2015 by former President Obama's administration. The decision to not make these standards more stringent were highly criticized by environmental advocacy groups as well as state and local governments and are currently being challenged in federal court. President Biden's administration is likely to reconsider the rulemaking and could make the standards more stringent. There was similar opposition to EPA’s November 2020 withdrawal of the “Once in Always in” policy requiring sources of hazardous air pollutants (HAPs) that were once considered a “major source” of HAPs to be subject to the more stringent emissions standards even if the source reduces its emissions below the “major source” threshold later. These EPA actions are very beneficial to industry since they reduce our regulatory burdens and compliance-related costs, however the rules, in their current form, may not be permanent with the pending litigation challenging the rules and President Biden's aggressive climate protection agenda. These air regulations are subject to review under the January 20, 2021 EO.


Furthermore, the State of Oregon’s development and implementation of its 2021 air quality protection plan in furtherance of the federal Regional Haze Rule may have a material impact on the Partnership. The EPA’s Regional Haze Rule requires states to improve visibility in national parks and wilderness within their jurisdictions by identifying sources of emissions and reasonable control methods to improve visibility. In the development phase of its state plan, the Oregon Department of Environmental Quality (ODEQ) has identified two GTN stations with turbines that may require GTN to incur material capital expenditures related to installation of emissions controls under the final state plan.

Federal Climate Change and Greenhouse Gas (GHG) Emissions

Climate Regulation


The threat of climate change continues to attract considerable public, governmentalattention in the U.S. and scientific attention. Asthroughout the globe. The spotlight on GHG regulation as a result, numerous proposals have been made and are likelymeans to combat climate change is expected to continue to be made atincrease compliance, construction, and operating costs for pipeline companies, including the international, national,Partnership, particularly under President Biden's aggressive climate change
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agenda, which included the issuance of a slate of executive orders within his first week in office demonstrating an unprecedented commitment to climate policy. Federal, state and state levels of governmentlocal governments are using tools like executive orders, legislation, regulatory actions, and more to regulate emissions of greenhouse gases (GHGs).GHGs. At the federal level, no comprehensive climate change legislation has been implemented to date, but thefor example, EPA has determined that emissions of GHGs present an endangerment to public health and the environment and subsequently has adopted regulations under existing provisions of the CAA that, among other things, establish construction and operating permit reviews regarding GHGs for certain large stationary sources that are already potential major sources of conventional pollutant emissions. The EPA has also promulgated regulations requiring the monitoring and reporting of GHGs and limiting GHGs directly from certain sources of emissions. Governmental, scientific, and public concern over GHG emissions from amongthe oil and gas industry, in particular, is growing considerably. President Biden’s new executive orders included a pause on new oil and gas leasing on federal lands, a revocation of the Keystone XL Presidential Permit, and more. Furthermore, while the EPA has historically been the sole federal regulator of GHGs, on December 27, 2020, former President Trump signed into law the 2020 PIPES Act, which notably made PHMSA another federal regulator of methane emissions from pipeline facilities. While we cannot predict the extent of the impact on the Partnership and the rest of the oil and gas industry from the increased GHG regulation, we can be sure that it will be material.

In recent years, there has been a particular focus on the regulation of the specific GHG, methane. Methane is the primary component of the natural gas flowing through our pipelines and is sometimes release into the atmosphere through pipeline leaks and blowdowns during pipeline maintenance, repair, testing, and other such activities. Natural gas companies and trade organizations are proactively evaluating the impact of methane to the climate crisis, approaches to measuring methane releases more accurately, and methane leak monitoring, reporting, detection, and mitigation practices and available technology. This research and analysis is not only important to understanding how to cost-effectively comply with the ever-increasing regulation of methane, but also to prove to fossil fuel opponents that the value of natural gas far outweigh the impact on climate.

Since the climate crisis is now regularly used to challenge the construction of natural gas pipeline projects, anytime methane regulations were relaxed under former President Trump's administration, particularly for the oil and gas industry, they were swiftly challenged in court, including a notable methane regulation in 2020. On August 13, 2020, the EPA, under former President Trump's administration issued policy and technical amendments to the NSPS, for stationary sources certain onshoreof air emissions. The policy amendments, (Methane Policy Rule), effective September 14, 2020, notably removed the transmission and storage sector from the regulated source category and rescinded methane and VOC requirements for the remaining sources that were established by former President Obama's administration. The technical amendment included changes to fugitive emissions monitoring and repair schedules for gathering and boosting compressor stations and low-production wells, recordkeeping and reporting requirements, and more. The Partnership sees the amendments as positive for the industry since it eliminates NSPS for natural gas transmission pipelines. However, it is important to note that the Partnership is still committed to many of the NSPS requirements for pipelines. This is important because, as expected, the amendments were immediately challenged in federal court. Moreover, President Biden's January 20, 2021 EO for Protecting Public Health and storage facilities, including gatheringthe Environment and boosting facilitiesRestoring Science to Tackle the Climate Crisis specifically directed EPA to review the technical amendment by September 2021. A reconsideration of the more controversial policy amendment is expected to follow. The same EO directed EPA to also propose existing source standards by September 2021. The extent to which these directives will impact the Partnership remains unknown.

State GHG Regulation

In the absence of consistency and blowdownspredictability in GHG emissions legislation, regulation and policies at the federal level, state and local governments have increasingly and more aggressively pursued GHG regulation within their own jurisdictions. This trend is likely to continue to grow under President Biden's leadership. A bipartisan coalition of natural gas transmission pipelines between compressor stations ingovernors from twenty-five states and U.S. territories have established the U.S. on an annual basis.

Additionally, whileClimate Alliance to combat climate change through the implementation of state policies that are consistent with the U.S. Congress has from timegoal of the Paris Agreement. Many of these policies are currently affecting or expected to time consideredaffect our assets residing in those specific states and increase our compliance-related costs, the extent of which is yet unknown.


In addition to issuing executive orders, legislation, and promulgating regulations for GHG emissions, states and local governments in California, Oregon, and Washington have taken advantage of tools like cap-and-trade programs, carbon taxes, and GHG reporting and tracking programs. For example, the Governor of Oregon issued an executive order in March 2020 to reduce emissions ofand regulate GHGs in the absencestate through the establishment of any significant activitynew annual GHG emissions reduction goals that must be met through the development of a new carbon cap and reduce program and enhanced clean fuel standards, which take effect no later than January 1, 2022. Rulemaking to implement the executive order has been ongoing since Spring 2020. The Northwest Gas Association, a trade organization of the Pacific Northwest Gas Industry, is representing the interests of interstate pipeline company members, including TC Energy, on the Rulemaking Advisory Committee for the development of the program. The extent to which GTN assets in Oregon will be impacted remains unknown, as the program is not expected to be proposed until Summer 2021. Additionally, the Washington Department of Ecology began rulemaking in 2020 to implement the Governor’s order to strengthen and standardize the consideration of climate change risks, vulnerability, and impacts in environmental assessments for certain major industrial and fossil fuel projects. During Washington’s 2020 legislative session, legislators also passed a law committing the State to becoming carbon-neutral by Congress2050 and strengthening intermediate reduction goals. In addition to California’s climate change plan that includes a GHG cap-and-trade program and methane leak regulations for oil and gas sites, the Governor issued an executive order in recent yearsSeptember 2020 requiring all new cars and light trucks sold in the state to adoptbe zero emission by 2035 and heavy and medium trucks to be zero emission by 2045. The promotion of electrification and use of legal tools for GHG regulation is also gaining traction at the local level. For example, in November 2020 a carbon tax was proposed to the Portland City Commission and in December 2020, the Governor of Washington and Mayor of Seattle followed in the footsteps of local government in California by introducing proposals that would cut demand for natural gas through building
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electrification ordinances. As such, legislation,the increasing state and local GHG regulation and promotion of electrification may materially affect our business, financial condition, demand for our systems and services, operations, compliance-related costs, and more.

Political Risks, Litigation Risks, Financial Risks

The political risks to the Partnership’s business for the immediate future is expected to be higher than it has been under former President Trump's administration. President Biden touted a comprehensive and aggressive environmental protection plan during his campaign that he promised to begin implementing immediately after taking office. Within his first week in the White House, President Biden took unprecedented executive actions in furtherance of human health and environmental protection, as well as environmental justice. Having identified climate change as one of his administration’s top four priorities, President Biden signed a number of state and regional efforts have emerged that are aimed at tracking and/or reducing GHG emissions by means of cap and trade programs.

Recent federal rulemakings have focused on the emission of methane, which is considered by the EPA as a GHG. In June 2016, the EPA published New Source Performance Standards, known as Subpart OOOOa, that require certain new, modified or reconstructed facilities in the oil and natural gas sector to reduce these methane gas and volatile organic compound emissions. These Subpart OOOOa standards will expand previously issued New Source Performance Standards published by the EPA in 2012, known as Subpart OOOO, by using certain equipment-specific emissions control practices, requiring additional controls for modified pneumatic controllers and pumps as well as compressors and imposing leak detection and repair requirements for natural gas compressor and booster stations that are modified through an increase in horsepower. However, over the past year the EPA has taken several steps to delay implementation of the methane rules. In June 2017, EPA proposed to stay the Subpart OOOOa standards for a period of two years and a separate 90-day stay of the standards to provide time for the 2-year stay to take effect while EPA reconsiders implementation of the Subpart OOOOa standards in their entirety. The EPA has not yet finalized the June 2017 proposed rulemaking and, as a result, the June 2016 rule remains in effect but future implementation of the 2016 rules is uncertain at this time.

In November 2017, the EPA published two Notices of Data Availability (NODAs) for Subpart OOOOa in the Federal Register and initiated a 30-day public comment period. One NODA relates to the June 2017 two year stay to reconsider the rule and the other NODA relates to the EPA's 90-day stay to cover the 60-day time-period between final publication of the 2-year stay in the Federal Register and the time the proposed 2-year stay takes effect. We do not believe that complianceexecutive actions, starting with the Subpart OOOOa regulations will have a material adverse effect on our operations even if the stay is ultimately vacated in court and the rule is fully implemented. However, given the uncertainty of policy and rulemaking regarding this rule the future effects on our pipelines cannot be predicted.

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On an international level, in June 2017, the U.S. Federal government announced its intent to withdraw from the 2015 international climate change agreement known asrejoining the Paris Agreement, the largest international effort to combat climate change, which former President Trump had officially withdrawn the U.S. from on November 4, 2020. Similarly, President Biden issued an executive order on January 27, 2021, directing the Secretary of the Interior to pause, to the extent consistent with applicable law, the issuance of new oil and gas leases on federal public lands and offshore waters pending completion of a comprehensive review and reconsideration of federal oil and gas permitting and leasing practices. President Biden's robust climate change plan includes a pledge to achieve a clean energy economy by 2050 by implementing a number of initiatives through executive orders, legislation, and regulations. His climate agenda includes methane regulation, promotion of electrification, and more. The political risk to the Partnership's business is further increased by climate change-related pledges made by candidates seeking public office at the local, state, and federal levels. During former President Trump's administration, Democratic Party-sponsored legislative initiatives, such as the Clean Leadership and Environmental Action for our Nation’s (CLEAN) Future Act and the U.S. State Department formally notifiedClimate Crisis Action Plan, were proposed in 2020 but did not advance beyond the United Nations in August 2017House. Now, the likelihood of passing comprehensive climate change legislation at the United States' intentfederal level has significantly increased. President Biden's climate agenda could require us or our customers to withdraw from the agreement. The Paris Agreement requires member countriesincur increased, potentially significant, costs to review and "represent a progression" in their intended nationally determined contributions, which setcomply with new, more stringent GHG emission reduction goals every five years beginning in 2020. Following the U.S. Federal government announcement to withdraw fromregulations. Additionally, entry into the Paris Agreement a number of U.S. State governments announced their commitment to the Paris Agreement. It is not possible at this time to predict how legislation or new regulations that may be adopted to address GHG emissions would impact our business. However, any such future laws and regulations that limit emissions of GHGs could adversely affect demand for the production of oil and natural gas that exploration and, production operators produce, some of whom are our customers, which could therebythus, reduce demand for the services we provide to our naturalcustomers.


Litigation Risk

Over the years, litigation risks have steadily increased as environmental protection, and particularly climate change, has garnered a great deal of attention on the global stage. Large interstate pipeline projects, in particular, have been challenged in court on various environmental grounds including water protection, endangered species and habitat protection, and climate change. Litigation risk for the Partnership increased in 2020 when environmental groups and various governments took issue with former President Trump's relaxation of burdensome regulation of industry. While environmental regulation under President Biden's administration is expected to be more stringent and thus more burdensome on industry, increased litigation will likely be due to industry challenging certain environmental regulations, legislation and executive directives. As mentioned earlier, there is a high litigation risk from those who want to oppose pipeline projects on the grounds they are using invalid NWP 12s and/or other NWPs.

Financial Risk

There are also growing financial risks as stakeholders of fossil fuel companies become increasingly concerned about the potential effects of climate change and consider shifting some or all of their investments into non-fossil fuel energy related sectors. Additionally, some institutional lenders, who provide financing to fossil-fuel energy companies, have become more attentive to sustainable lending practices and may elect not to provide funding for fossil fuel energy companies. Additionally, the expected increase in the regulation of oil and gas transportation services.

companies under President Biden, particularly on the basis of climate change, will likely materially increase compliance-related costs, costs to litigate regulatory actions, and more. Finally, it should be noted that many scientists have concluded that increasing concentrations of GHGs in the Earth's atmosphere may produce climate changesclimatic events like storms and floods which may have a material adverse effect on the financial condition and results of operations on us and our customers.


Waste Remediation Related Environmental Issues Potentially Impacting the Partnership
We own, lease, or operate numerous properties that have significant physical effects,been used for natural gas pipeline operations for many years. Additionally, some of our properties have been operated by third parties or by previous owners or operators whose treatment and disposal of hazardous substances, wastes, or petroleum hydrocarbons was not under our control. Under environmental laws such as increased frequencyTSCA, CERCLA, and severityRCRA, we could incur strict joint and several liability due to damages to natural resources as well as for remediating hydrocarbons, hazardous substances or wastes disposed of storms, droughtsor released by us or prior owners or operators. For example, during routine maintenance activities of our pipelines and floodsrelated facilities, we may discover historical hydrocarbon or PCB contamination. Discovery of such contaminants would require prompt notification to the appropriate governmental authorities and corrective actions to timely mitigate the contamination. Moreover, an accidental release of materials into the environment during our operations may cause us to incur significant costs and liabilities. Remedial costs, penalties from governmental agencies, and other climatic events. Significant changesdamages could have a material adverse effect on our liquidity, results of operations, and financial condition. We also could incur costs related to the clean-up of third-party sites to which we sent regulated substances for disposal and for damages to natural resources or other claims related to releases of regulated substances at or from such third-party sites.

Total Financial Impact of Compliance with Environmental Laws and Regulations
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Currently, the ultimate financial impact of complying with U.S. environmental laws and regulations is indeterminable. Compliance obligations can result in temperaturesignificant costs associated with installing and other weather eventsmaintaining pollution controls, fines and penalties resulting from any regulatory violations, and potential limitations on operations. Remediation obligations can result in significant costs associated with the investigation and remediation of contaminated facilities, and with damage claims arising from the contamination. The timing and complete extent of future expenditures related to environmental matters is difficult to estimate accurately because (1) interpretation and enforcement of environmental laws and regulations are constantly changing or evolving; (2) new claims can be brought against our existing or discontinued assets; (3) our pollution control and clean-up cost estimates may change, especially when our current estimates are based on preliminary site investigations or agreements; (4) new contaminated facilities and sites may be found, or what we know about existing sites and facilities could change; and (5) where there is potentially more than one responsible party involved in litigation, we cannot estimate our joint and several liability with certainty.

We have incurred and will continue to incur operating and capital expenditures costs, some of which could be material, as environmental laws and regulations continue to evolve, change, and become stricter and more robust. Additional regulatory restrictions continue to be placed on activities that may have a detrimental effect on the environment. For this reason, new laws and regulations, amendments and reinterpretations, and stricter enforcement permitting programs result in compliance and remediation obligations that can have many effectsa material adverse effect on our operations and financial position now and in the future. Historically, our environmental compliance costs have not had a material adverse effect on our results of operations; however, there can be no assurance that such costs will not be material in the future or that such future compliance will not have a material adverse effect on our business ranging from an impact on demand, availability and commodity prices, to efficiency and output capability.

U.S. Department of Transportation operational results.


Pipeline and Hazardous Materials Safety Administration (PHMSA)

Matters


Our gas pipeline systems are subject to federal pipeline safety statutes, such as the Natural Gas Pipeline Safety Act of 1968 (NGPSA), the Pipeline Safety Improvement Act of 2002 (the PSI Act), the Pipeline Inspection, Protection, and Enforcement Act of 2006 (the PIPES Act), the Pipeline Safety, Regulatory Certainty, and Job Creation Act of 2011 (the 2011 Pipeline Safety Act) and the Protecting Our Infrastructure of Pipelines and Enhancing Safety Act of 2016 (the 2016 Pipeline Safety Act), as well as regulations promulgated and administered by the PHMSA.U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration (PHMSA). The NGPSA regulates safety requirements in the design, construction, operation and maintenance of natural gas pipeline facilities. Pursuant to the authority granted under the NGPSA, PHMSA has promulgated regulations governing pipeline design, installation, testing, maximum operating pressures, pipeline patrols and leak surveys, minimum depth requirements and emergency procedures, as well as other matters intendedfacilities to ensure adequate protection for the public and to prevent accidents and failures. The PSI Act established mandatory inspections for all U.S. natural gas transportation pipelines, and some gathering lines in high consequence areas (HCAs), which are areas where a release could have the most significant adverse consequences, including high population areas. The PIPES Act required mandatory inspections for certain natural gas transmission pipelines in HCAs and required that rulemaking be issued for,Pursuant to this act, PHMSA has promulgated regulations governing, among other things, maximum operating pressures, pipeline control room management. Pursuant to the authority granted under the NGPSA, as amended,patrols and leak surveys, public awareness, operation and maintenance procedures, operator qualification, minimum depth requirements and emergency procedures. Additionally, PHMSA has established a series of rulespromulgated regulations requiring pipeline operators such as our operator, TransCanada, Iroquois and MNOC to develop and implement integrity management programs to comprehensively evaluate certain relatively higher risk areas, known as HCAs and moderate consequence areas (MCAs) along pipelines and take additional safety measures to protect people and property in these areas in the event of a pipeline leak or rupture. The HCAs for naturalgas pipelines are predicated on high-population areas, which may include Class 3 and Class 4 areas. An MCA for gas pipelines is also based on population totals in addition to the existence of certain principal, high-capacity roadways, but an MCA does not meet the relative higher population totals of an HCA and therefore are located outside of HCA coverages.
Historically, our pipeline safety compliance costs have not had a material adverse effect on our results of operations; however, there can be no assurance that such costs will not be material in the future or that such future compliance will not have a material adverse effect on our business, financial condition or results of operations.

Moreover, changes to pipeline safety laws by Congress and regulations by PHMSA that result in more stringent or costly safety standards could have a significant adverse effect on us and similarly situated midstream operators. For instance, several years after publishing the gas mega proposed rulemaking, PHMSA elected to split the proposed rulemaking into three rules, also known as the "Gas Mega Rule" with the first of these rules, relating to onshore gas transmission pipelines, published as a final rule in HCAsOctober 2019. The October 2019 final rule relates specifically to gas transmission pipelines and, among other things, updates reporting and records retention standards for covered pipelines and expands the level of required integrity assessments that requiremust be completed on certain pipeline segments outside of high consequence areas (HCAs). The October 2019 final rule also requires operators to review maximum allowable operating pressure records and perform specific remediation activities where records are not available. The Partnership will continue to assess the performanceoperational and financial impact related to the October 2019 final rule over its 15-year implementation window that began July 1, 2020 and seek to optimize recovery of frequent inspectionsthose costs. The remaining rulemakings comprising the Gas Mega Rule are expected to be issued in 2021. On January 11, 2021, PHSMA finalized a published June 2020 proposed a rulemaking that would seek to ease regulatory burdens on gas transmission, distribution and other precautionary measures. PHMSA may assess penalties for violations of these and other requirements imposed by its regulations. The 2011gathering lines. However, we expect President Biden's administration to reconsider this rulemaking or possibly have it withdrawn.

Congress enacted the 2016 Pipeline Safety Act, also increaseswhich reauthorized PHMSA’s hazardous liquid and gas pipeline programs only through federal Fiscal Year 2019. On December 27, 2020, the maximum penalty2020 PIPES Act was signed into law and authorizes general funding for violationPHMSA as well as prescribes a number of priorities for PHMSA through federal fiscal year 2023. Key items include: additional due process protections for operators during enforcement proceedings; updating the federal safety standards for the operation and maintenance of large-scale liquefied natural gas facilities; clarifying the applicability of the pipeline safety regulations to idle pipelines; and reviewing each operator’s operation and maintenance plan within two years. The 2020 Pipes
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Act also established a new three-year program for advancing pipeline safety technologies, testing, and operational practices and increasing the number of PHMSA inspection and enforcement personnel by 20%.

Other proposed rules:

Valve Installation and Minimum Rupture Detection Standards- On February 6, 2020 PHMSA published a Notice of Proposed Rulemaking (NPRM) entitled Pipeline Safety: Valve Installation and Minimum Rupture Detection Standards. The NPRM proposes to revise existing regulation for gas transmission pipelines to address congressional mandates, incorporate recommendations from $100,000the National Transportation Safety Board, and to $200,000 per violation per dayreduce the consequences of violationlarge-volume, uncontrolled releases of natural gas pipeline ruptures. Specifically, the NPRM seeks to set requirements for the placement, function, and maintenance of automatic shut off and/or remote-control mainline valves to mitigate the effects of a pipeline rupture. The NPRM also seeks to set time requirements for the identification of, and response to, pipeline ruptures.

Class Location Change Requirements- On October 14, 2020, PHMSA, published an NPRM entitled Class Location Change Requirements. PHMSA is proposing to revise the Federal Pipeline Safety Regulations to amend the requirements for gas transmission pipeline segments that experience a change in class location. Under the existing regulations, pipeline segments located in areas where the population density has significantly increased must perform one of the following actions: reduce the pressure of the pipeline segment, pressure test the pipeline segment to higher standards, or replace the pipeline segment. This proposed rule would add an alternative set of requirements operators could use, based on implementing integrity management principles and pipe eligibility criteria, to manage certain pipeline segments where the class location has changed from $1 milliona Class 1 location to $2 milliona Class 3 location. Through required periodic assessments, repair criteria, and other extra preventive and mitigative measures, PHMSA expects this alternative approach would provide long-term safety benefits consistent with the current natural gas pipeline safety rules while also providing cost savings for pipeline operators.

While the above rulemaking process is expected to be lengthy, efforts to modernize the existing PHMSA regulations could have a related series of violations. Effective April 27, 2017, to account for inflation, those maximum civil penalties were increased to $209,002 per violation per day,material effect on our costs.

Compliance with a maximum of $2,090,022 for a series of violations.

The ongoingexisting pipeline safety laws and implementing regulations could cause our pipeline systems to incur significant and unanticipated capital and operating expenditures for repairs or upgrades deemed necessary to ensure their continued safe and reliable operation and to comply with the federal pipeline safety statutes and regulations.

Additional rule makings The promulgation of new laws and rulemaking regarding pipeline safety are likely. In June 2016,likely and, despite compliance with applicable laws and regulations, our pipelines may experience leaks and ruptures that could impact the 2016 Pipeline Safety Act was passed, extending PHMSA's statutory mandate through 2019surrounding population and among other things, requiring PHMSA to complete certain of its outstanding mandates under the 2011 Act. As aenvironment. This may result in May 2016, PHMSA proposed new rules for natural gas transmissioncivil and/or criminal fines and gathering lines that would, if adopted, impose more stringent inspection, reporting,penalties or third-party property damage claims and integrity management requirements on operators. However, to date, no further action has been taken with respect to this

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proposed rulemaking. The safety enhancement requirements and other provisions of the 2011 Pipeline Safety Act as further amended by the 2016 Pipeline Safety Act, as well as any implementation of PHMSA rules or any issuance or reinterpretation of guidance by PHMSA or any other state agencies with respect thereto, could require usadditional testing or upgrades on the pipeline system unrelated to install newthe incident. It is possible that these costs may not be covered by insurance or modified safety controls, pursue additional capital projects, conduct maintenance programs on an accelerated basis, or result in a temporary or permanent reduction in maximum allowable operating pressure, which would reduce available capacity on our pipelines, any or all of which could result in our incurring increased operating costs that could be significant, and have a material adverse effect on our results of operations or financial condition.

recoverable through rate increases. There can be no assurance that future compliance with the requirements will not have a material adverse effect on our pipeline systems and the Partnership's financial position, operational costs, cash flow and our ability to maintain current distribution levels to the extent the increased costs are not recoverable through rates.

From time to time, despite compliance with applicable rules and regulations, our pipelines may experience incidents that result in leaks and ruptures that may impact the surrounding population and environment. This may result in enforcement by regulatory agencies that may seek civil and/or criminal fines and penalties or third party property damage claims, and could require our pipelines to conduct testing of the pipeline system or upgrade segments of a pipeline unrelated to the incident which costs may not be covered by insurance or recoverable through rate increases.

U.S. Occupational Safety and Health Administration (OSHA)

Our pipelines are also subject to the requirementsa number of the OSHA and other federal and state agencies that address employee healthlaws and safety. In general, we believe that TransCanada's, Iroquois'regulations, including the federal Occupational Safety and MNOC's programsHealth Act and costs incurred are addressing the OSHA requirements and protectingcomparable state statutes, whose purpose is to protect the health and safety of employees. Basedworkers. The OSHA and analogous state agencies oversee the implementation of these laws and regulations. Additionally, the OSHA hazard communication standard, the EPA community right-to-know regulations under Title III of the federal Superfund Amendment and Reauthorization Act and comparable state statutes require that information be maintained concerning hazardous materials used or produced in our operations and that this information be provided to employees, state and local government authorities and citizens.

Historically, worker safety and health compliance costs have not had a material adverse effect on new regulatory developments,our results of operations; however, there can be no assurance that such costs will not be material in the future or that such future compliance will not have a material adverse effect on our business and operational results. While pipeline operators may increase expenditures in the future to comply with higher industry and regulatory safety standards. However,standards, such increases in costs of compliance, and the extent to which they might be recoverable through our pipeline'spipeline’s rates, cannot be estimated at this time.

Cyber security

We rely on our information technology to process, transmit and store electronic information, including information pipeline operators use to safely operate our assets. We, our operators and other energy infrastructure companies in jurisdictions where we do business continue to face cyber security risks. Cyber security events could be directed against companies in the energy infrastructure industry.

A breach in the security of our information technology could expose our business to a risk of loss, misuse or interruption of critical information and functions. This could affect our operations, damage our assets and result in safety incidents, damage to the environment, reputational harm, competitive disadvantage, regulatory enforcement actions and potential litigation, which could have a material adverse effect on our operations, financial position and results of operations.

TransCanada,

TC Energy, the indirect parent of our General Partner and the operator of most of our assets, has a cyber security strategy which aligns with industry and recognized standards for cyber security. This strategy includes cyber security risk assessments, preventions, continuous monitoring of networks and other information sources for threats to the organization, comprehensive
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incident response plans/processes and a cyber security awareness program for employees. TransCanadaAlthough TC Energy also has insurance which covers reasonably foreseeablemay cover losses due tofrom physical damage to our facilities and losses incurred by others, as a result of a cyber security event. These polices do not, however, cover losses that may result from a cyber security event, that prevents TransCanada from operating our facilities butthe insurance does not resultcover all events in any physical damage.all circumstances. There is no certainty that costs incurred related to securing against these threats will be recovered through rates.

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EMPLOYEES


HUMAN CAPITAL RESOURCES

We do not have any employees. WeWhile human capital is necessary for us to operate our business, we are managed and operated by our General Partner.Partner, therefore we do not directly make decisions regarding our service providers. Subsidiaries of TransCanadaTC Energy operate most of our pipelines systems pursuant to operating agreements, with the exception of the Iroquois pipeline system and the PNGTS joint facilities.Joint Facilities. The Iroquois pipeline system is operated by a wholly owned subsidiary of Iroquois. The PNGTS joint facilitiesJoint Facilities are operated by MNOC, a wholly owned subsidiary of MNE. MNE is a subsidiary of Enbridge Inc.

AVAILABLE INFORMATION

We make available free of charge on or through our website (www.tcpipelineslp.com) our annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and any amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended (the Exchange Act), as soon as reasonably practicable after we electronically file the material with, or furnish it to, the Securities and Exchange Commission (SEC). Copies of our Code of Business Conduct and Ethics, Corporate Governance Guidelines and the Audit Committee Charter of our General Partner are also available on our website under "Corporate“Corporate Governance." We will also provide copies of these documents at no charge upon request. The information contained on our website is not part of this report.

Item 1A. Risk Factors


Limited partner interests are inherently different from the capital stock of a corporation, although many of the business risks to which we are subject are similar to those that would be faced by a corporation engaged in a similar business. Realization of any of the risks described below could have a material adverse effect on our business, financial condition, including valuation of our equity investments, results of operations and cash flows, including our ability to make distributions to our unitholders. Investors should review and carefully consider all of the information contained in this report, including the following discussion of risks when making investment decisions relating to our Partnership.

RISKS RELATED TO THE PARTNERSHIP

The amount of cash we have available for distribution to holders of our common units depends primarily on our cash flow, financial reserves and working capital borrowings, rather than on our profitability, which may prevent us from making distributions, even during periods in which we earn net income.


The amount of cash we have available for distribution depends primarily upon our cash flows and not solely on profitability, which will be affected by non-cash items. As a result, we may make cash distributions during periods when losses are incurred and may not make cash distributions during periods when we earn net income.

Our ability to make cash distributions is dependent primarily on our cash flow, financial reserves and working capital borrowings.

The amount of cash we can distribute on our units principally depends upon the amount of cash we generate from our operations, which will fluctuatefluctuates based on, among other things:

the rates we charge for our transmission and changes in demand for our transportation services;

legislative or regulatory action affecting the demand for natural gas, the supply of natural gas, the rates we can charge, how we contract for services, our existing contracts, operating costs and operating flexibility;

the commodity price of natural gas, which could reduce the quantities of natural gas available for transport;

the creditworthiness of our customers;

TC PipeLines, LPAnnual Report2017    25


changes in, or new, statutes, regulations or governmental policies by federal, state and local authorities with respect to protection of the environment;

changes in accounting rules and/or tax laws or their interpretations;

nonperformance or force majeure by, or disputes with or changes in contract terms with, major customers, suppliers, dealers, distributors or other business partners; and

changes in, or new, statutes, regulations, governmental policies and taxes, or their interpretations.

Significant changes in energy prices could impact supply and demand balances for natural gas.

Prolonged low oil and natural gas prices cancould result in supply and demand imbalances that impact availability of natural gas for transportation on our pipeline systems.

In early March 2020, the market experienced a precipitous decline in crude oil prices in response to oil oversupply and demand concerns due to the economic impacts of the COVID-19 pandemic. Additionally, in April 2020, extreme shortages of
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transportation and storage capacity caused the New York Mercantile Exchange (NYMEX) West Texas Intermediate oil futures price to go as low as approximately negative $37. This negative pricing resulted from the holders of expiring front month oil purchase contracts being unable or unwilling to take physical delivery of crude oil and accordingly forced to make payments to purchasers of such contracts in order to transfer the corresponding purchase obligations.

Although oil prices have partially recovered from what was experienced in April, the COVID-19 pandemic and economic downturn could further negatively impact domestic and international demand for crude oil and natural gas and a positive impact on demand but canprolonged period of low crude oil and natural gas prices would negatively impact exploration and development of new crude oil and natural gas supplies thatsupplies. In response to the sharp decline in oil and natural gas prices, many producers have announced cuts or suspension of exploration and production activities and some state regulators are considering mandating the proration of production of hydrocarbons. A drilling reduction could impact the availability of natural gas to be transported by our pipelines. Similarly, high commodity prices can increase levels of exploration and development but can reduce demand for natural gas leading to reduced demand for transportation services. Sustained low or high oil and natural gas prices could also impact shippers'counterparties’ creditworthiness that could impactand their ability to meet their transportation service cost obligations.

Such developments could have an adverse effect on our assets, liabilities, business, financial condition, results of operations and cash flow.

Capital projects or future acquisitions that appear to be accretive may fail to materialize as anticipated or nevertheless reduce our cash available for distributions.

If we do notcannot successfully identifyfinance and complete expansioncapital projects or make and integrate acquisitions that are accretive, we may not be able to continue tomaintain or grow our cash distributions.

Our strategy is to continue to grow the cash distributions on our common units by expanding our business. Our ability to grow depends on our ability to undertake acquisitions and organic growth projects, the ability of our pipeline systems to complete expansion projects and make and integrate acquisitions that result in an increase in cash per common unit generated from operations. Our ability to complete successful, accretive expansion projects or acquisitions is dependent upon many factors, including our ability to secure necessary rights-of-way or regulatory approvals, our ability to finance such expansion projects or acquisitions on economically acceptable terms and the degree to which our assumptions about volumes, reserves, revenues, costs and customer commitments materialize. In addition, many U.S. environmental laws provide for citizen suits, and environmental groups frequently use these provisions to challenge environmental reviews and permits issued in connection with pipeline infrastructure projects, resulting in costly delays. Acquisitions may not be available to the Partnership or occur at the prices, terms, with the same structure or on the schedule consistent with historical transactions.

TransCanada may offer to sell its assets to the Partnership, subject to TransCanada's funding needs and market conditions. There can be no assurance, however, as to when and on what terms these assets will be offered to the Partnership.

In addition, we face competition for acquisitions from investment funds, strategic buyers and commercial finance companies. These companies may have higher risk tolerances or different risk assessments that permit them to offer higher prices that we may be unwilling to match.

Expansion projects or future acquisitions that appear to be accretive may nevertheless reduce our cash from operations on a per unit basis.

Even if we complete expansioncapital projects or make acquisitions that we believe will be accretive, these expansioncapital projects or acquisitions may nevertheless reduce our cash from operations on a per-unit basis. Any expansioncapital project or acquisition involves potential risks, including:

an inability to complete expansioncapital projects on schedule or within the budgeted cost due to, among other factors, the unavailability of required construction personnel, equipment or materials and the risk of cost overruns resulting from inflation or increased costs of materials, labor and equipment;

a decrease in our liquidity as a result of using a significant portion of our available cash or borrowing capacity to finance the project or acquisition;

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an inability to receive cash flows from a newly built or acquired asset until it is operational; and

unforeseen difficulties operating in new business areas or new geographic areas.

As a result, our new facilities may not achieve expected investment returns, which could adversely affect our results of operations, financial position or cash flows. If any completed expansioncapital projects or acquisitions reduce our cash from operations on a per unitper-unit basis, our ability to make distributions may be reduced.

Exposure to variable interest rates and general volatility in the financial markets and economy could adversely affect our business, our common unit price, results of operations, cash flows and financial condition.

As of December 31, 2017, $435 million of our total $2,415 million of consolidated debt was subject to variable interest rates. As a result, our results of operations, cash flows and financial condition could be adversely affected by significant increases in interest rates. From time to time, we may enter into interest rate swap arrangements which may increase or decrease our exposure to variable interest rates but there is no assurance that these will be sufficient to offset rising interest rates. As of December 31, 2017, the $500 million 2013 Term Loan Facility was hedged by fixed interest rate swap and forward starting swap arrangements.

For more information about our interest rate risk, see Part II, Item 7A. "Quantitative and Qualitative Disclosures About Market Risk – Market Risk."

Our indebtedness may limit our ability to obtain additional financing, make distributions or pursue business opportunities.


The amount of the Partnership'sPartnership’s current or future debt could have significant consequences to the Partnership including the following:

our ability to obtain additional financing, if necessary, for working capital, acquisitions, payment of distributions or other purposes may be impaired, or such financing may not be available on favorable terms;

credit rating agencies may view our debt level negatively;

covenants contained in our existing debt arrangements will require us to continue to meet financial tests that may adversely affect our flexibility in planning for and reacting to changes in our business;

our need for cash to fund interest payments on the debt reduces the funds that would otherwise be available for operations, future business opportunities and distributions to our unitholders; and

our flexibility in responding to changing business and economic conditions may be limited.

In addition, our ability to access capital markets to raise capital on favorable terms will be affected by our debt level, our operating and financial performance, the amount of our current maturities and debt maturing in the next several years and by prevailing market conditions. Moreover, if the rating agencies were to downgrade our credit ratings, then we could experience an increase in our borrowing costs, face difficulty accessing capital markets or incurring additional indebtedness, be unablelack the ability to receive open credit from our suppliers and trade counterparties, be unable to benefit from swings in market prices and shifts in market structure during periods of volatility in the oil and gas markets or suffer a reduction in the market price of our common units. If we are unable to access the capital markets on favorable terms at the time a debt obligation becomes due in the future, we may refinance some of our debt obligations through bank credit, as opposed to long-term public debt securities or equity securities, or sell assets. The price and terms upon which we might receive such extensions or additional bank credit, if at all, could be more onerous than those contained in existing debt agreements. Any such arrangements could, in turn, increase the risk that our leverage may adversely affect our future financial and operating flexibility and thereby impact our ability to pay cash distributions at expected rates.

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If we are unable to obtain needed capital or financing on satisfactory terms to fund expansioncapital projects or future acquisitions, our ability to make quarterly cash distributions may be diminished or our financial leverage could increase.

The prolonged low oil and natural gas prices in the energy industry


Over time, our industry’s fundamentals have historically made and will likely continue to make it difficult for some entities to obtain funding. In order to fund our expansionsome capital project expenditures, we willmay be required to use cash from our operations, incur borrowings or sell additional common units or other limited partner interests. Using cash from operations will reduce distributable cash flow to our common unitholders. Our ability to obtain bank financing or to access the capital markets for future equity or debt offerings may be limited by our financial condition at the time of any such financing or offering, the covenants in our debt agreements, general economic conditions and contingencies and uncertainties that are beyond our control. Even if we are successful in obtaining funds for expansion capital project expenditures through equity or debt financings, the terms thereof may be less favorable to us and could limit our ability to pay distributions to our common unitholders. In addition, incurring additional debt may significantly increase our interest expense and financial leverage, and issuing additional limited partner interests may result in significant common unitholder dilution and increase the aggregate amount of cash required to maintain the then-current distribution rate, which could materially decrease our ability to pay distributions at the then-current distribution rate. If funding is not available to us when needed, or is available only on unfavorable terms, we may be unable to execute our business plans, complete acquisitions or otherwise take advantage of business opportunities or respond to competitive pressures, any of which could have a material adverse effect on our financial condition, credit ratings, results of operations, cash flows and ability to make quarterly cash distributions to our unitholders.

An

Any impairment of anour goodwill, long-lived assets or equity investment, a long-lived asset or goodwill couldinvestments will reduce our earnings orand could negatively impact the value of our common units.


Consistent with GAAP,U.S. Generally Accepted Accounting Principles (GAAP), we evaluate our goodwill for impairment at least annuallyannually. Our long-lived assets and our equity investments, and long-lived assets, including intangible assets with finite useful lives, are evaluated whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. For the investments we account for under the equity method, the impairment test requires us to consider whether the fair value of the equity investment, as a whole, not just that of the underlying net assets, has declined and whether that decline is other than temporary. If we determine that impairment is indicated, we would be required to take an immediate noncashnon-cash charge to earnings with a correlativecorresponding effect on equity and balance sheet leverage as measured by debt to total capitalization.
For example, in the fourth quarter of 2018, we recognized impairment charges on Tuscarora’s goodwill balance amounting to $59 million and Bison’s long-lived assets totaling $537 million.
The risk of future impairments related to our goodwill, long-lived assets or equity investments, will continue to exist. If underlying business assumptions change, there can be no assurance that a future impairment charge will not be made with respect to our remaining balances of our goodwill, equity investments and long-lived assets. This could have a negative impact on the common unit price.

As an example, in 2015, we recognized an impairment charge on our equity investment in Great Lakes amounting to $199 million and in 2016, our analysis on Tuscarora's goodwill balance indicated that the excess of its fair value over the carrying value, including goodwill was less than 10 percent.

There is a risk of future impairments related to our equity investments, goodwill or long-lived assets. If assumptions relied upon change, there can be no assurance no future impairment charge will be made with respect to our equity investments, goodwill and long-lived assets.

For more information, see Part II, Item 6 “Selected Financial Data” for summary of impairments recognized on our equity investments, goodwill and long-lived assets in the last 5 years. See also Part II, Item 7. "Management's"Management’s Discussion and Analysis of Financial Condition and Results of Operations – Critical Accounting Estimates - Impairment of Equity Investments, Goodwill, and Long-Lived Assets and Equity Investments."

We do not own a controlling interest in our Equity Investmentsequity investments in Northern Border, Great Lakes and Iroquois, which limits our ability to control these assets.


We do not own a controlling interest in our Equity Investmentsequity investments in Northern Border, Great Lakes and Iroquois and are therefore unable to cause certain actions to occur without the agreement of the other owners. As a result, we may be unable to control the amount of cash distributions received from these assets or the cash contributions required to fund our share of their operations. The major policies of these assets are established by their management committees, which consist of individuals who are designated by each of the partners and including us. These management committees generally require at least the

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affirmative vote of a majority of the partners'partners’ percentage interests to take any action. Because of these provisions, without the concurrence of other partners, we would be unable to cause these assets to take or not to take certain actions, even though those actions may be in the best interests of the Partnership or these assets. Further, these assets may seek additional capital contributions. Our funding of these capital contributions would reduce the amount of cash otherwise available for distribution to our unitholders. In the event we electeddo not to,elect or wereare unable to make a capital contribution to these assets;assets, our ownership interest would be diluted.

Any disagreements with the other owners of these assets could adversely affect our ability to respond to changing economic or industry conditions, which could have a material adverse effect on our business, results of operations, financial condition and ability to make cash distributions to unitholders.


RISKS RELATED TO THE TC ENERGY MERGER

Because the market value of TC Energy common shares that Unaffiliated TCP Unitholders will receive in the TC Energy Merger may fluctuate, Unaffiliated TCP Unitholders cannot be sure of the market value of the merger consideration that they will receive in the TC Energy Merger.
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As merger consideration, Unaffiliated TCP Unitholders will receive a fixed number of TC Energy common shares, not a number of shares that will be determined based on a fixed market value. The market value of TC Energy common shares and the market value of TC PipeLines common units at the effective time may vary significantly from their respective values on the date that the TC Energy Merger Agreement was executed or at other dates, such as the date of this Annual Report on Form 10-K or the date of the special meeting. Stock price changes may result from a variety of factors, including changes in TC Energy’s or the Partnership’s respective businesses, operations or prospects, regulatory considerations and general business, market, industry or economic conditions. The exchange ratio will not be adjusted to reflect any changes in the market value of TC Energy common shares, the comparative value of the Canadian dollar and U.S. dollar or market value of the TC PipeLines common units. Therefore, the aggregate market value of the TC Energy common shares that an Unaffiliated TCP Unitholder is entitled to receive at the time that the TC Energy Merger is completed could vary significantly from the value of such shares on the date of this Annual Report on Form 10-K, the date of the special meeting or the date on which an Unaffiliated TCP Unitholder actually receives its TC Energy common shares.

Upon completion of the TC Energy Merger, TC PipeLines unitholders will become TC Energy shareholders, and the market price for TC Energy common shares may be affected by factors different from those that historically have affected TC PipeLines.

Upon completion of the TC Energy Merger, TC PipeLines unitholders will become TC Energy shareholders. TC Energy’s businesses differ from those of the Partnership, and accordingly, the results of operations of TC Energy will be affected by some factors that are different from those currently affecting the results of operations of the Partnership.

The TC Energy Merger Agreement may be terminated in accordance with its terms and there is no assurance when or if the TC Energy Merger will be completed.

The completion of the TC Energy Merger is subject to the satisfaction or waiver of a number of conditions as set forth in the TC Energy Merger Agreement, including, among others, (i) the adoption of the TC Energy Merger Agreement by an affirmative vote of the holders of a majority of all of the outstanding TC PipeLines common units entitled to vote at the special meeting, (ii) the approval in connection with the TC Energy Merger for listing on the NYSE and the Toronto Stock Exchange of the TC Energy common shares to be issued to TC PipeLines unitholders in connection with the TC Energy Merger, subject to official notice of issuance, (iii) the expiration or early termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 and any required approval or consent under any other applicable antitrust law must have been obtained, (iv) no governmental entity of competent jurisdiction shall have enacted, issued, promulgated, enforced or entered any law or governmental order (whether temporary, preliminary or permanent) that is in effect and restrains, enjoins, makes illegal or otherwise prohibits the consummation of the transactions contemplated by the TC Energy Merger Agreement, (v) the registration statement having been declared effective by the SEC and (vi) other customary closing conditions, including the accuracy of each party’s representations and warranties (subject to specified materiality qualifiers), and each party’s material compliance with its covenants and agreements contained in the TC Energy Merger Agreement. There can be no assurance as to when these conditions will be satisfied or waived, if at all, or that other events will not intervene to delay or result in the failure to complete the TC Energy Merger.

In addition, the Partnership will be obligated to (i) pay TC Energy a termination fee equal to $25 million or (ii) pay TC Energy an expense reimbursement amount equal to $4 million. The TC Energy Merger Agreement also provides that upon termination of the TC Energy Merger Agreement under certain circumstances TC Energy will be obligated to pay the Partnership an expense reimbursement amount equal to $4 million.

Failure to complete, or significant delays in completing, the TC Energy Merger could negatively affect the trading prices of the TC PipeLines common units or the future business and financial results of TC PipeLines.

The completion of the TC Energy Merger is subject to certain customary closing conditions and there is no certainty that the various closing conditions will be satisfied and that the necessary approvals will be obtained. If these or other conditions are not satisfied or if there is a delay in the satisfaction of such conditions, then TC Energy and TC PipeLines may not be able to complete the TC Energy Merger timely or at all, and such failure or delay may have other adverse consequences. If the TC Energy Merger is not completed or is delayed, TC Energy and TC PipeLines will be subject to a number of risks, including:

TC Energy and the Partnership may experience negative reactions from the financial markets, including negative impacts on the market price of TC PipeLines common units, particularly to the extent that their current market price reflects a market assumption that the TC Energy Merger will be completed;
TC Energy and the Partnership will not realize the expected benefits of the combined company; and
some costs relating to the TC Energy Merger, such as investment banking, legal and accounting fees, and financial printing and other related charges, must be paid even if the TC Energy Merger is not completed.
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The Partnership and TC Energy will incur substantial transaction fees and costs in connection with the TC Energy Merger.

The Partnership and TC Energy have incurred and expect to incur additional material non-recurring expenses in connection with the TC Energy Merger and completion of the transactions contemplated by the TC Energy Merger Agreement, including costs relating to obtaining required approvals. The Partnership and TC Energy have incurred significant legal, advisory and financial services fees in connection with the process of negotiating and evaluating the terms of the TC Energy Merger. Additional significant unanticipated costs may be incurred in the course of coordinating the businesses of the Partnership and TC Energy after completion of the TC Energy Merger. Even if the TC Energy Merger is not completed, the Partnership and TC Energy will need to pay certain costs relating to the TC Energy Merger incurred prior to the date the TC Energy Merger was abandoned, such as legal, accounting, financial advisory, filing and printing fees. Such costs may be significant and could have an adverse effect on the parties’ future results of operations, cash flows and financial condition. In addition to its own fees and expenses, each of TC PipeLines and TC Energy may be required to reimburse the other party for its reasonable out-of-pocket expenses incurred in connection with the TC Energy Merger Agreement, subject to a cap of $4 million, in the event the TC PipeLines unitholders or TC Energy shareholders, respectively, do not approve the matters required to be voted upon by TC PipeLines unitholders or TC Energy shareholders, respectively, and the TC Energy Merger Agreement is terminated.

President Biden’s revocation of the federal permit for the Keystone XL will negatively affect TC Energy's earnings.

On January 20, 2021, President Biden signed an executive order revoking the existing Presidential Permit for the Keystone XL pipeline. As a result, TC Energy has suspended advancement of the project while it reviews the decision, assesses its implications and considers its options. TC Energy has ceased capitalizing costs, including interest during construction, effective January 20, 2021, and is evaluating the carrying value of its investment in the pipeline, net of project recoveries. TC Energy expects to record a substantive, predominantly non-cash, after-tax charge to its earnings in first quarter 2021, which will be excluded from comparable earnings. Additionally, accounting implications in first quarter 2021 and beyond, will depend on the assessment and consideration of options, including the impacts that this has had on contractual arrangements. As a result, TC Energy cannot quantify the magnitude of the impairment charge and related recoveries at this time. These steps, absent intervening events, will negatively affect TC Energy's earnings and could have a negative impact on TC Energy’s stock price.


RISKS RELATED TO OUR PIPELINE SYSTEMS

We may experience changes in demand for our transportation services which may lead to an inability of our pipelines to charge maximum rates or renew expiring contracts.


Our primary exposure to market risk and competitive pressure occurs at the time existing shipper contracts expire and are subject to renegotiation and renewal. The valueMajority of our pipeline systems’ revenue is generated from long-term, fixed fee transportation services dependsagreements. Depending on a shipper's demandmarket conditions at the time of contract expiration and renewal, shippers may be unwilling to renew their contracts for pipeline capacity and the price paid for that capacity.long terms or at favorable rates. The inability of our pipelinespipeline systems to extend or replace expiring contracts on comparable terms could have a material adverse effect on our business, financial condition, results of operations and our ability to make cash distributions. Our ability to extend and replace expiring contracts, particularly long-term firm contracts, on terms comparable to priorexisting contracts, depends on many factors beyond our control, including:

changes in upstream and downstream pipeline capacity, which could impact the pipeline'spipeline’s ability to contract for transportation services;

the availability and supply of natural gas in Canada and the U.S.;

competition from alternative sources of supply;

competition from other existing or proposed pipelines;

contract expirations and capacity on competing pipelines;

changes in rates upstream or downstream of our pipeline systems, which can affect our pipeline systems'systems’ relative competitiveness;

basis differentials between the market location and location of natural gas supplies;

the liquidity and willingness of shippers to contract for transportation services;services on a long-term fixed fee basis; and

regulatory developments.

Natural gas on Bison is currently not flowing as a resultthe impact of a change inregulations, public policy and consumer demand for its services. There can be no assurance that we will be able to replace Bison's existing contracts and maintain its current revenues which could significantly reduce our earnings and cash flows.

Natural gasrenewal energy on Bison is currently not flowing in response to the relative cost advantage of WCSB – and Bakken-sourced gas versus Rockies production. Bison has not experienced a decrease in its revenue as it is fully contracted on a ship-or-pay basis through January of 2021. However, we may not be able to renew or contract for this capacity if this market condition continues to persist.

While we are currently working on other strategic alternatives to maximize the value of this asset which include discussions with producers in the area to determine the best use for Bison, including if the asset can be reversed, redirected or repurposed, there is a risk that options available at this time will not bring back the same level of revenue Bison currently generates. More importantly, Bison's revenues comprise approximately 19 percent of our consolidated revenues and if we are unsuccessful in securing contracts for Bison in the future or the options available to us do not

TC PipeLines, LPAnnual Report2017    29


materialize, there could be a significant reduction in our earnings and cash flows and ultimately, an impairment on Bison's long lived assets.

shipper contracting practices.

Rates and other terms of service for our pipeline systems are subject to approval and potential adjustment by FERC, which could limit theirthe ability to recover all costs of capital and operations and negatively impact their rate of return, results of operations and cash available for distribution.


Our pipeline systems are subject to extensive regulation over virtuallyeffectively all aspects of their business, including the types and terms of services they may offer to their customers, construction of new facilities, creation, modification or abandonment of
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services or facilities, and the rates that they can charge to shippers. Under the NGA, their rates must be just, reasonable and not unduly discriminatory. Actions by FERC, (see Item 1. "Business – Government Regulation")such as refusing to honor existing moratoria on rate changes, could adversely affect our pipeline systems'systems’ ability to recover all of their current or future costs and could negatively impact their rate of return, results of operations and cash available for distribution.

For example, in December 2016, FERC issued a Notice of Inquiry Regarding the Commission's Policy for Recovery of Income Tax Costs (Docket No. PL17-1-000) requesting Initial Comments regarding how to address any double recovery resulting from FERC's current income tax allowance and rate of return policies that are in effect since 2005.

Various comments have been received by FERC and most recently, comments on how the 2017 Tax Act will affect the income tax recovery allowed on regulated pipelines. While the outcome of the inquiry is still pending, we believe that there is not likely to be a definitive resolution of these issues for some time. However, the outcome This could result in changes going forward to FERC's treatment of income tax allowances in the cost of service or to the discountedlower than anticipated distributable cash flow return on equity that could have an impact on the rates of any of our interstate natural gas pipelines.

We are dependent on the continued availability of and demand for, natural gas in relation to our pipeline systems.

As the long-term contracts on our pipeline systems expire, the demand for transportation service on our pipeline systems will depend on the availability of supplynecessitate a distribution reduction from the basins connected to our systems and the demand for natural gas in the markets we serve. Natural gas availability from basins depends upon numerous factors including basin production costs, production levels, environmental regulation, availabilitycurrent quarterly level of storage and natural gas prices. Our pipeline systems are also dependent on the continued demand for natural gas in their market areas. If supply and/or demand should significantly fall, our pipeline systems may be at risk for loss of contracting or contracting at discounted rates which could impact our revenues.

Our pipeline systems' business systems could be negatively impacted by security threats, including cyber security threats, and related disruptions.

In 2012, the U.S. Department of Homeland Security issued public warnings that indicate that pipelines and other assets might be specific targets of terrorist organizations or "cyber security" events. During 2016, PHMSA posted warnings to all pipeline owners and operators of the importance of safeguarding and securing their pipeline facilities and monitoring their supervisory control and data acquisition (SCADA) systems for abnormal operations and/or indications of unauthorized access or interference with safe pipeline operations based on recent incidents involving environmental activists.

These potential security events might include our pipeline systems or operating systems and may result in damage to our pipeline facilities and affect our ability to operate or control our pipeline assets; their operations could be disrupted and/or customer information could be stolen.

We depend on the secure operation of our physical assets to transport the energy we deliver and our information technology to process, transmit and store electronic information, including information TransCanada uses to safely operate our pipeline systems. Security breaches could expose our business to a risk of loss, misuse or interruption of critical physical assets or information and functions that affect the pipeline operations. Such losses could result in operational impacts, damage to our assets, public or personnel safety incidents, damage to the environment,

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reputational harm, competitive disadvantage, regulatory enforcement actions, litigation and a potential material adverse effect on our operations, financial position and results of operations. There is no certainty that costs incurred related to securing against threats will be recovered through rates.

$0.65 per common unit.

If our pipeline systems do not make additional capital expenditures sufficient to offset depreciation expense, our rate base will decline and our earnings and cash flow could decrease over time.


Our pipeline systems are allowed to collect from their customers a return on their assets or "rate base"“rate base” as reflected in their financial records, as well as recover a portion of that rate base over time through depreciation. In the absence of additions to the rate base through capital expenditures, the rate base will decline over time, and in the event of a rate proceeding, this could result in reductions in revenue, earnings and cash flows of our pipeline systems.

Our pipeline systems'systems’ indebtedness and commitments may limit their ability to borrow additional funds, make distributions to us or capitalize on business opportunities.


Our pipeline systems'systems’ respective debt levels and commitments could have negative consequences to each of them and the Partnership, including the following:

their ability to obtain additional financing, if necessary, for working capital, capital expenditures, acquisitions or other purposes may be impaired, or such financing may not be available on favorable terms;

their need for cash to fund interest payments on the debt reduces the funds that would otherwise be available for operations, future business opportunities and distributions to us;

their debt level may make them more vulnerable to competitive pressures or a downturn in their business or the economy generally; and

their debt level may limit their flexibility in responding to changing business and economic conditions.

Our pipeline systems'systems’ ability to service their respective debt will depend upon, among other things, future financial and operating performance which will be affected by prevailing economic conditions and financial, business, regulatory and other factors, many of which are beyond their control.

In the event the PXP project does not proceed, PNGTS may be responsible for the reimbursement of TransCanada's upstream capital expenditures on the related Canadian system expansions, which could have a negative impact on PNGTS' ability to make cash distributions to its partners.

In connection with PXP, PNGTS has entered into an arrangement with TransCanada regarding the construction of certain facilities on its system that will be required to fulfill future contracts on the PNGTS' system. In the event the TransCanada expansions terminate prior to the in-service date of the final phase of PXP, PNGTS could be required to reimburse TransCanada for up to the amount of TransCanada PXP Expenditures incurred to date of termination, the majority of which is expected to be incurred following the anticipated receipt dates of required regulatory approvals, prior to the end of phase II of the project. As of December 31, 2017, the total incurred was approximately $3 million. If PNGTS were required to reimburse TransCanada for TransCanada PXP Expenditures, it would reduce cash available for distributions to us and therefore reduce our cash available for distributions to unitholders. A project construction plan is in place to minimize expenditures until certain regulatory approvals are received.

See also Part I, Item 1. "Business-Recent Business Developments" for further information on the PXP Project.

Our pipeline systems are subject to operational hazards and unforeseeable interruptions that may not be covered by insurance.


Our pipeline systems are subject to inherent risks including, among other events,such as, ruptures, earthquakes, adverse weather conditions, and other natural disasters;disasters, terrorist activity, civil disobedience or acts of aggression; damage to a pipeline by a third party;aggression, third-party activity, and pipeline or equipment failures. Eachfailure. Any of these risks could result incause damage to one of our pipeline systems, business interruptions, a release of pollution or contaminants into the environment andor other

TC PipeLines, LPAnnual Report2017    31



environmental hazards, or injuries to persons and property. These risksThe Partnership could cause us to suffer a substantial loss of revenue and incur significant costs to the extent they are not covered by insurance under our pipeline systems'systems’ shipper contracts, as applicable. In addition,Additionally, if one of our pipeline systems was to experience a serious pipeline failure, a regulator could require our pipelinesus to conduct testing of the pipeline system or upgrade segments of a pipeline unrelated to the failure, whichresulting in potential costs may not be covered by insurance or recoverable through rate increases. We could also face a potential reduction in operational parameters which could reduce the capacity available for sale.

Our pipelines could be subjectpipeline systems may experience significant costs and liabilities related to penalties and fines if they fail to complycompliance with FERC regulations and pipeline safety laws and regulations.


Our pipelines are subjectedsubject to substantial penalties and fines if FERC findsin the event that our pipeline systems have failed to comply with all applicable FERC-administered statutes, rules, regulations and orders, or the terms of their tariffs on file with FERC. Under the Energy Policy Act of 2005, FERC has civil penalty authority under the NGA and NGPAthe Natural Gas Policy Act of 1978 to impose penalties for violations of up to approximately $1.2$1.31 million per day for each violation, to revoke existing certificate authority and to order disgorgement of profits associated with any violation.

Our pipeline systems may experience significant costs and liabilities related to compliance with pipeline safety laws and regulations.

Our

Additionally, our pipeline systems are subject to pipeline safety statutes and regulations administered by PHMSA whichthat require pipeline operators to develop integrity management programs.

Thecompliance with stringent operational and safety standards. For example, the ongoing implementation of the pipeline integrity management programs could cause our pipeline systems to incur significant and unanticipated capital and operating expenditures for repairs or upgrades deemed necessary to ensure their continued safe and reliable operation andoperation. Additionally, we are subject to pipeline safety requirements that may impose more stringent safety obligations, require installation of new or modified safety controls, or perform capital or operating projects on an accelerated basis. Failure to comply with the federal pipeline safety statutes and regulations. Additionally, any failure to comply with PHMSA'sPHMSA’s regulations could subject our pipeline systems to penalties, fines or restrictions on our pipeline systems'systems’ operations. New legislation or regulations adopted by PHMSA may impose more stringent requirements applicable to integrity management programs and other pipeline safety aspects of our operations, which could cause us to incur increased operating and capital costs and result in operational delays and costs of operations. For example,delays.


Our compliance with these applicable PHMSA has adopted or proposed pipeline safety regulations in 2011 and, more recently, in 2016 in response to legislation passed by the U.S. Congress that, among other things, increased the penalties for safety violations, established additional safety requirements for newly constructed pipelines and required studies of safety issues that could result in the adoption of new regulatory requirements by PHMSA for existing pipelines, and empowered PHMSA to address imminent hazards by imposing emergency restrictions, prohibitions and safety measures on owners and operators of regulated pipeline facilities without prior notice or an opportunity for a hearing.

The cost of new PHMSA regulations to our pipeline systems could have a material adverse effect on our operations, financial position, cash flows, and our ability to maintain current distribution levels to the extent the increased costs

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are not recoverable through rates.

For further discussion on pipeline safety matters, see Part I, Item 1 “Government Regulation” – “Pipeline Safety Matters.”

Our pipeline systems are regulated by federal, state and local laws and regulations that could impose costs for compliance with environmental protection requirements.

Each of our pipeline systems is subject to federal, state and local environmental laws and regulations that could impose significant compliance-related costs and enforcement policies. Potential liabilities, may arise relatedor make the execution of our growth projects uneconomic or impossible.


Owing to protectionthe nature of the environment and natural resources. New environmental laws, regulations or enforcement policies could be implemented that significantly increase our pipeline systems' compliance costs. As an example, under the Clean Air Act the 2015 revisionsoperations, we are subject to the National Ambient Air Quality Standards for ozone may result in the addition of non-attainment designations in additional counties in which our pipeline systems operate. States have submitted their initial non-attainment designations to the EPA and the agency expects to issue final non-attainment designation in 2018. Depending upon State Implementation Plans and the outcome of any legal challenges to such designations, additional permitting delays and expenditures for pollution control equipment could occur. This example illustrates the uncertainty to which proposed laws, regulations or reforms, if any, will be adopted and what impact they might ultimately have on our operations or financial results.

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Under certainstringent environmental laws and regulations we maythat compel compliance with numerous obligations that are applicable to our operations including acquisition of permits or other approvals before conducting regulated activities, restrictions on the types, quantities and concentration of materials that can be exposedreleased into the environment; limitation or prohibition of construction and operating activities in environmentally sensitive areas such as wetlands, urban areas, wilderness regions and other protected areas; requiring capital expenditures to comply with pollution control requirements, and imposition of substantial liabilities for pre-existing contamination that arisepollution resulting from our operations. Failure to comply with these laws and regulations or any newly adopted laws or regulations may result in assessment of sanctions including administrative, civil and criminal penalties, the imposition of investigatory, remedial and corrective action obligations or the incurrence of capital expenditures; the occurrence of restrictions, delays or cancellations in the permitting or performance of projects, and the issuance of orders enjoining or conditioning performance of some or all of our operations in a particular area. Environmental compliance and enforcement costs and liabilities in connection with our past or current operations. For example, during routine maintenance activities, we may discover historical hydrocarbon or polychlorinated biphenyl contamination, which may require notification to the appropriate governmental authorities and corrective action to address.

There also exist legal initiatives directly affecting our customers that could indirectly affect our operations by reducing the need for our services. Such developments could cause our customers to incur potentially significant added costs to comply with such requirements and experience delays or curtailment in the pursuit of exploration, development or production activities, which subsequently could reduce demand for our transportation services.

Current and future emissions regulation legislation or regulations restricting emissions of GHG could result in increased operating costs.

There have been a number of legislative initiatives to regulate GHG emissions; however, uncertainty exists regarding the impact of new and proposed GHG laws and regulations. Moreover, implementation of GHG regulations is the subject of significant litigation which has created uncertainty in compliance requirements with both the regulatory agencies and industry. Recent federal rulemakings have focused on the emission of methane, which is considered by the EPA as a GHG. For example, in June 2016, the EPA published New Source Performance Standards, known as Subpart OOOOa, that require certain new, modified or reconstructed facilities in the oil and natural gas sectorpipelines may come, for example, from air emissions and product-related discharges, impacts to reduce these methane gasregulated water bodies and volatile organic compound emissions. These Subpart OOOOa standards will expand previously issued New Source Performance Standards published by the EPA in 2012 and known as Subpart OOOO, by using certain equipment-specific emissions control practices, requiring additional controls for modified pneumatic controllers and pumpsthreatened or endangered species as well as compressorshistorical industry operations and imposing leak detectionwaste disposal practices. For example, an accidental release from one of our facilities could subject us to substantial liabilities arising from environmental cleanup and repair requirementsrestoration costs, claims made by neighboring landowners and other third parties for personal injury, natural gas compressorresource and booster stations that are modified through an increase in horsepower. However, overproperty damages and fines or penalties for related violations of environmental laws or regulations. Moreover, the past year the EPA has taken several steps to delayadoption and implementation of these methane standards,new environmental laws, regulations, judicial decisions, and enforcement policies could potentially increase our compliance-related costs, particularly in the realm of climate change and GHG regulation. Some high-profile federal environmental laws and regulations that may impose significant compliance related costs and make the execution of our pipeline projects more difficult include the uncertainty surrounding the use of the USACE’s NWPs, specifically NWP 12, for utility construction, maintenance, repair, and relocation activities affecting WOTUS. The ever-changing definition of WOTUS, amendments made to the CWA Section 401 water quality certification process, the criminalization of the “incidental take” of migratory birds, its nests, or its eggs under the MBTA, policy and technical amendments made to NSPS for stationary sources of air emissions, the “Once in Always in” HAPs policy, and the agency proposed a rulemakingnew authority given to PHMSA to regulate methane emissions from pipelines are additional examples of federal actions that will likely impose additional compliance-related costs and make project execution more difficult.


Furthermore, the Partnership may be specifically burdened by compliance-related costs at the state level in June 2017Oregon due to stay the requirements for a period of two years and revisit implementation of the Subpart OOOOa rulesEPA’s Regional Haze Rule. In 2020, the State of Oregon identified two GTN Stations as significant sources of regional haze precursor emissions to Class I areas in their entirety. The EPA has not yet published a final rule and the June 2016 rule remains in effect, but future implementationOregon. This identification was made as part of the 2016 Subpart OOOOa standardsState’s development of its 2021 air quality protection plan implementing the federal Regional Haze Rule that requires states to improve visibility in national parks and wilderness. The Rule required ODEQ to identify sources of emissions that could be reduced with reasonable control methods to improve visibility in Class I areas under its state plan. The identification of the two GTN stations triggered the need to submit a four-factor analysis for five turbines at the stations. A four-factor analysis under the Regional Haze Rule is uncertain at this time. Although itused to determine if there are “reasonable” controls available for reducing the visibility impairing emissions, primarily Nitrogen Oxides (NOx) for the GTN facilities. Based on the four-factor analyses ODEQ removed one turbine from consideration for additional controls. If GTN is not possible at this timeultimately required to predict how legislation or new regulationsinstall NOx controls on the four remaining units under review in Oregon’s final state implementation plan, the capital expenditures that maywill be adopted to address GHG emissions would impact our business, any such future laws and regulationsincurred by GTN could result in increasedbe material.

Increased compliance costs, or additional operating restrictions,the incurrence of remedial costs, penalties from governmental agencies, and other damages could have a material adverse effect on our liquidity, results of operations, and financial condition. For further discussion on environmental matters, see Part I, Item 1 “Government Regulation” – “Environmental Matters”.


Our operations are subject to a series of risks arising from the threat of climate change that could lead to increased construction and operating costs and could also potentially reduce demand for our systems and services.

Climate change continues to attract considerable public, governmental, and scientific attention in the United States and internationally. The Partnership, along with the greater oil and gas industry, has a vested interest in the climate change debate since increased scrutiny on the cause of climate change subjects our operations to various regulatory, political, litigation, and financial risks. These risks may lead to material adverse effects on our business, financial condition, and results of operations. In the United States, no comprehensive federal climate change legislation has been implemented but President Biden taking office and Democratic control of the U.S. House of Representatives and Senate, the adoption of such legislation is very likely in the coming years. President Biden's administration has made efforts to combat climate change one of its top four priorities and, as promised, took immediate action within President Biden's first week in office by issuing a number of executive actions addressing climate change. These early executive actions included an executive order to rejoin the Paris Agreement, and directive to heads of federal departments and agencies to review agency actions promulgated, issued, or adopted between January 20, 2017 and January 20, 2021, for consistency with public health and environmental protection policy goals of the EO. If inconsistent, the EO directs agencies to consider suspending, revising, or rescinding the agency actions. Notably, the EO includes directives related
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to the establishment of the social cost of GHGs and specifically directs EPA to review its recent methane technical amendment to the NSPS for stationary sources and to propose revisions to existing source standards by September 2021. The new Administration also revoked the Keystone XL presidential permit and put a pause on new oil and gas leases on federal lands. Moreover, the EPA and numerous state and local governments have pursued legal initiatives to reduce GHG emissions using tools like cap-and-trade programs, carbon taxes, GHG reporting and tracking programs, and regulations that require monitoring and reporting of GHG emissions and limiting GHGs directly from certain sources. The general trend towards increased regulation of GHG emissions in the oil and natural gas sector as a means to combat climate change, supported by President Biden's administration’s climate agenda, could increase the Partnership’s costs of regulatory compliance and/or reduce demand for our systems and services due to regulations and policies incentivizing consumer use of alternative energy sources (such as wind, solar geothermal, tidal and biofuels), and imposing limitations and restrictions on fossil fuel-related activities that reduce demand for GHG-intensive fossil fuels. Litigation and financial risks as a result of climate change may also adversely impact fossil fuel activities by our customers that, in turn, could have an adverse effect on the demand for our service. These political, litigation, and financial risks may result in our customers restricting or cancelling production activities, incurring liability for infrastructure damages as a result of climatic changes, or impairing their ability to continue to operate in an economic manner, which also could reduce demand for our services financial condition, results of operations and cash flows.

The Cap and Invest Legislation (HB 4001 and SB 1507) that is scheduled to be proposed during the 2018 Oregon legislative session could result in higher cost of operating the GTN pipeline system

The Oregon Legislature is considering several GHG proposals that would regulate GHG emissions through a "cap-and-invest" program. The Cap and Invest Legislation (HB 4001 and SB 1507) is scheduled to be proposed during the 2018 Oregon legislative session that, in its current form, would provide GHG allowances to be allotted and sold by various entities. The information provided has not allowed us to reasonably anticipate or estimate the outcome of this proposed legislation at this time. Additionally, the Oregon Department of Environmental Quality are considering proposed rules to amend existing air quality rules. Comments to the proposed "Cleaner Air Oregon" rulemaking was scheduled for early 2018. At this time, we cannot reasonably estimate the impact of the proposed amended rules in its final form; however, it is expected that these rules will become finalized in 2018.

Recent pipeline safety legislation and proposed regulations could result in more stringent requirements on our facilities and systems that could trigger significant capital and operating costs.

The 2016 Pipeline Safety Act requires that PHMSA publish periodic updates on the status of those mandates outstanding from the 2011 Pipeline Safety Act, of which numerous initiatives remain to be completed. The mandates yet to be acted upon include requiring certain shut-off valves on transmission lines, mapping all high consequence areas, and shortening the deadline for accident and incident notifications.

TC PipeLines, LPAnnual Report2017    33


In March 2016, PHMSA announced a proposed rulemaking that would impose new or more stringent requirements for certain natural gas lines and gathering lines. Additional requirements proposed by this proposed rulemaking would increase PHMSA's integrity management requirements for natural gas pipelines. To date, no further action with respect to this proposed rulemaking has been taken. We continue to monitor proposed rulemaking developments and evaluate its potential impact, if any, of 2016 Pipeline Safety Act, in light of the many PHMSA initiatives and mandates. At this time, we cannot predict the ultimate impact of this legislation, and subsequent revisions to regulations on our operations; however, the adoption of any new legislation or regulations regarding increased pipeline safety could cause us to incur increased capital and operating costs, which costs could be significant.

We are exposed to credit risk when a customer fails to perform its contractual obligations.

Our pipeline systems are subject to a risk of loss resulting from the nonperformance by a customer of its contractual obligations. Our exposure generally relates to receivables for services provided and future performance over the remaining contract terms under firm transportation contracts. Our pipelines' FERC approved tariffs limit the amount of credit support that they may require in the event that a customer's creditworthiness is or becomes unacceptable. If a significant customer has financial problems, which results in a delay or failure to pay for services provided by them or contracted for with them, it could have a material adverse effect on the Partnership’s business and operations. For further discussion on environmental matters, see Part I, Item 1 “Government Regulation” – “Legal Initiatives to Combat Climate Change and Restrict Greenhouse Gas (GHG) Emissions”.


Certain chemical substances in the natural gas pipeline systems could cause damage or affect the ability of our pipeline systems or third-party equipment to function properly, which may result in increased preventative and corrective action costs.
The presence of a chemical substance, dithiazine, has been discovered at several facilities on the GTN system, as well as some upstream and downstream connecting pipelines. Dithiazine is a byproduct of triazine which is a liquid chemical scavenger used in the natural gas production industry to remove hydrogen sulfide (H2S) from natural gas streams. None of our pipelines utilize triazine in the facilities or operations, however, dithiazine may drop out of gas streams, under certain conditions, in a powdery form at certain points of pressure reduction. The powdered dithiazine has the potential to interfere with equipment functionality if a sufficient quantity of the material accumulates in certain appurtenances, leading to increased preventative and corrective action costs.
GTN and TC Energy are working collaboratively with customers, producers, vendors, federal and state regulators, trade associations, and other stakeholders to address the matter. GTN has also taken steps, incurred costs and made capital expenditures to address the matter. Between 2018 and 2020, GTN has spent capital expenditures of approximately $20 million and has incurred operating costs of approximately $3 million. Unless the issue is resolved, GTN expects to spend approximately $3 million in capital expenditures and $1 million in operating costs in 2021 to further resolve the matter. There is no assurance that significant additional costs will not be incurred in the future or that dithiazine or other substances will not be identified on our other pipeline systems.

The operation of portions of our pipeline systems requires easements or rights-of-way across land owned by Native American tribes, governmental authorities and other third parties, the cost or denial of which could result in disruption to operations and higher costs that adversely affect our business, financial condition and results of operations.

We do not own the


The majority of the land on which our pipeline systems are located which could result in higher costs and disruptionsis leased pursuant to our operations, particularly with respect to easements and rights-of-way across Indian tribal lands.

We do not own the majority of the land on which our pipeline systems are located. We obtain easements, rights-of-way and other land use rights to construct and operate our pipeline systems from individual landowners, Native American tribes, governmental authorities and other third parties. Someparties, the majority of these rights expire after a specified period of time. As a result, wewhich are subject to the possibility of more onerous termsperpetual and increased costs to renew expiring easements, rights-of-way and other land use rights. While we generally are able to obtain these rightsobtained through agreementagreements with land owners or legal process, if necessary, rights-of-way across Indiannecessary. Certain rights, however, are subject to renewal and, with respect to tribal land require approval of the applicable tribal governing authority andheld in trust by the Bureau of Indian Affairs (the "BIA"). If efforts(BIA), approval by the applicable tribal governing authorities and the BIA. The cost of obtaining or renewing rights-of-way across tribal land can be significantly high. The inability to retain existing land use rightsrenew a right-of-way on tribal land at a reasonable cost are unsuccessful, ourcould require capital expenditures for removal and relocation of portions of pipeline systems could also be subject to a disruption of operations and increaseddisrupt operations. Such costs to re-route the applicable portion of our pipeline system located on tribal land. Increased costs associated with renewing or obtaining new easements or rights-of-way and any disruption of operations could negatively impact the results of operations and cash available for distribution offrom our pipeline systems.

Our Great Lakes pipeline system has rights-of-way expiring during


During the second quarter of 2018, onrights-of-way expired for approximately 7.6 miles of our Great Lakes pipeline acrosson tribal land located within the Fond du Lac Reservation (Fond Du Lac) and Leech Lake Reservation (Leech Lake) in Minnesota and the Bad River Reservation (Bad River) in Wisconsin. WeGreat Lakes subsequently received a demand letter in April 2019 from the Fond Du Lac Tribal Chairman to immediately cease operation of the Great Lakes pipeline and begin the process of removing all infrastructure from tribal land. Following receipt of the demand letter, Great Lakes executed a Memorandum of Agreement with Fond Du Lac relating to the negotiation of a new right-of-way. Great Lakes continues to negotiate with Fond Du Lac and are negotiatingin advanced discussions with Bad River. In late 2020, Great Lakes has reached an agreement with Leech Lake subject to renewfurther approval from the rights-of-way withBIA.

While Great Lakes has progressed on the tribal authorities.renewal process, we cannot predict the full outcome of these negotiations. If we are unable to reach agreement regarding these rights-of way prior to expirationobtain new easements or rights-of-way across all or a portion of the existing easements, we expect to continue operating thetribal lands at reasonable rates, or at all, Great Lakes pipeline while continuing good faith negotiations with the tribal authorities to obtain the necessary rights. If these discussions ultimately are unsuccessful, we couldmay be required to remove pipe fromacquire the tribal landsnecessary rights at significant cost or remove and re-route the applicable portionportions of the Great Lakes pipeline system. While the outcome of these negotiations or the abilityat significant capital expense and disruption to reach agreement prior to expiration of the existing rights is uncertain, the impact of a disruption of operations or significantly increased costs to renew the rights-of-waythat could have a material adverse effect on our financial condition, results of operations and cash flows.

RISKS RELATED TO OUR PARTNERSHIP STRUCTURE

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We do not have the same flexibility as corporations to accumulate cash and equity to protect against illiquidity in the future.


We are required by our Partnership Agreement to make quarterly distributions to our unitholders of all available cash, reduced by any amounts of reserves for commitments and contingencies, including capital and operating costs and debt

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service requirements. The value of our units and other limited partner interests may decrease in direct correlation with decreases in the amount we distribute per common unit. Accordingly, if we experience a liquidity shortfall in the future, we may not be able to recapitalize by issuing more equity.


Common unitholders have limited voting rights and are not entitled to elect our General Partner or its board of directors.

directors and cannot remove our General Partner without its consent.


The General Partner is our manager and operator. Unlike the stockholders in a corporation, holders of our common units have only limited voting rights on matters affecting our business. Unitholders have no right to elect our General Partner or its board of directors. The members of the board of directors of our General Partner, including the independent directors, are appointed by its parent company and not by the unitholders.

Common unitholders cannot remove

Additionally, our General Partner without its consent.

Our General Partner may not be removed except by the vote of the holders of at least 662/3 percent of the outstanding common units. These required votes would include the votes of common units owned by our General Partner and its affiliates. TransCanada'sTC Energy's ownership of 24.2approximately 24 percent of our outstanding common units at December 31, 2017,2020, has the practical effect of making removal of our General Partner difficult.

In addition, the Partnership Agreement contains some provisions that may have the effect of discouraging a person or group from attempting to remove our General Partner or otherwise change our management. If our General Partner is removed as our general partner under circumstances where cause does not exist and common units held by our General Partner and its affiliates are not voted in favor of that removal:

any existing arrearages in the payment of the minimum quarterly distributions on the common units will be extinguished; and

our General Partner will have the right to convert its general partner interests and its incentive distribution rights into common units or to receive cash in exchange for those interests.

Our Partnership Agreement restricts voting and other rights of unitholders owning 20 percent or more of our common units.


The Partnership Agreement contains provisions limiting the ability of unitholders to call meetings of unitholders or to acquire information about our operations, as well as other provisions limiting the unitholders'unitholders’ ability to influence the manner or direction of management. Further, if any person or group other than our General Partner or its affiliates or a direct transferee of our General Partner or its affiliates acquires beneficial ownership of 20 percent or more of any class of common units then outstanding, that person or group will lose voting rights with respect to all of its common units. As a result, unitholders have limited influence on matters affecting our operations and third parties may find it difficult to attempt to gain control of us or influence our activities.

We may issue additional common units and other partnership interests, without unitholder approval, which would dilute the existing unitholders'unitholders’ ownership interests. In addition, issuance of additional common units or other partnership interests may increase the risk that we will be unable to maintain the quarterly distribution payment at current levels.


Subject to certain limitations, we may issue additional common units and other partnership securities of any type, without the approval of unitholders.

Based on the circumstances of each case, the issuance of additional common units or securities ranking senior to, or on parity with, the common units may dilute the value of the interests of the then-existing holders of common units in the net assets of the Partnership. In addition, the issuance of additional common units may increase the risk that we will be unable to maintain the quarterly distribution payment at current levels.

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Our common unitholders'unitholders’ liability may not be limited if a court finds that unitholder action constitutes control of our business.


A general partner generally has unlimited liability for the obligations of a limited partnership, except for those contractual obligations of the partnership that are expressly made without recourse to the general partner. We are organized under Delaware law and conduct business in a number of other states. The limitations on the liability of holders of limited partner interests for the obligations of a limited partnership have not been clearly established in some states. Our unitholders could be liable for any and all of our obligations as if our unitholders were a general partner if a court or government agency determined that:

the Partnership had been conducting business in any state without compliance with the applicable limited partnership statute; or

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the right, or the exercise of the right, by the unitholders as a group to remove or replace our General Partner, to approve some amendments to the Partnership Agreement or to take other action under the Partnership Agreement constituted participation in the "control"“control” of the Partnership'sPartnership’s business.

In addition, under some circumstances, such as an improper cash distribution, a unitholder may be liable to the Partnership for the amount of a distribution for a period of three years from the date of the distribution.

Our General Partner has a limited call right that may require common unitholders to sell their common units at an undesirable time or price.


If at any time our General Partner and its affiliates own 80 percent or more of the common units, the General Partner will have the right, but not the obligation, which it may assign to any of its affiliates or us, to acquire all of the remaining common units held by unaffiliated persons at a price generally equal to the then current market price of the common units. As a consequence, unitholders may be required to sell their common units at a time when they may not desire to sell them or at a price that is less than the price they would desire to receive upon sale. Unitholders may also incur a tax liability upon a sale of their units. As of December 31, 2017,2020, the General Partner and its affiliates own approximately 24.224 percent of our outstanding common units.

Our Partnership Agreement replaces our general partner'spartner’s fiduciary duties to holders of our common units with contractual standards governing its duties.


The Partnership Agreement contains provisions that eliminate the fiduciary standards to which the General Partner would otherwise be held by state fiduciary duty law and replaces those duties with several different contractual standards. For example, our Partnership Agreement permits our General Partner to make a number of decisions in its individual capacity, as opposed to in its capacity as our General Partner, free of any duties to us and our unitholders other than the implied contractual covenant of good faith and fair dealing, which means that a court will enforce the reasonable expectations of the partners where the language in the Partnership Agreement does not provide for a clear course of action. This provision entitles our General Partner to consider only the interests and factors that it desires and relieves it of any duty or obligation to give any consideration to any interest of, or factors affecting, us, our affiliates or our limited partners. Examples of decisions that our General Partner may make in its individual capacity include:

how to allocate corporate opportunities among us and its other affiliates;

whether to exercise its limited call right;

whether to seek approval of the resolution of a conflict of interest by the conflicts committee of the Board of Directors;

whether to elect to reset target distribution levels;

whether to transfer the incentive distribution rights to a third party; and

whether or not to consent to any merger or consolidation of the Partnership or amendment to the Partnership Agreement.

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By purchasing a common unit, a common unitholder agrees to become bound by the provisions in the Partnership Agreement, including the provisions discussed above.

The NYSE does not require a publicly traded limited partnership like us to comply with certain of its corporate governance requirements.


Our common units are listed on the NYSE. Because we are a publicly traded limited partnership, the NYSE does not require us to have, and we do not intend to have, a majority of independent directors on our Board of Directors or to establish a nominating and corporate governance committee. Accordingly, unitholders will not have the same protections afforded to certain corporations that are subject to all of the NYSE corporate governance requirements.

The credit and business risk profiles of our General Partner and TransCanadaTC Energy could adversely affect our credit ratings and profile.

The credit and business risk profiles of our General Partner and TransCanadaTC Energy may be factors in credit evaluations of a master limited partnership because our General Partner can exercise control over our business activities, including our cash distribution and acquisition strategy and business risk profile. Other factors that may be considered are the financial conditions of our General Partner and TransCanada,TC Energy, including the degree of their financial leverage and their dependence on cash flows from us to service their indebtedness.

Costs reimbursed to our General Partner are determined by our General Partner and reduce our earnings and cash available for distribution.


Prior to making any distribution on the common units, we reimburse our General Partner and its affiliates, including officers and directors of the General Partner, for all expenses incurred by our General Partner and its affiliates on our behalf. During the year ended December 31, 20172020, we paid fees and reimbursements to our General Partner in the amount of $4 million (2016(2019 and 2015 – $3 million)2018- $4 million each). Our General Partner, in its sole discretion, determines the amount of these expenses. In addition, our General Partner and its affiliates may provide us with services for which we will be charged reasonable fees as determined by
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the General Partner. The reimbursement of expenses and the payment of fees could adversely affect our ability to make distributions.

Changes in TransCanada'sTC Energy’s costs or their cost allocation practices could have an effect on our results of operations, financial position and cash flows.


Under the Partnership Agreement, the Partnership'sPartnership’s pipeline systems operated by TransCanadaTC Energy are allocated certain costs of operations at TransCanada'sTC Energy’s sole discretion. Accordingly, revisions in the allocation process or changes to corporate structure may impact the Partnership'sPartnership’s operating results. TransCanadaTC Energy reviews any changes and their prospective impact for reasonableness, however there can be no assurance that allocated operating costs will remain consistent from period to period.


TAX RISKS

Our tax treatment depends on our status as a partnership and exemption from entity level taxes for U.S. federal, state and local income tax purposes, as well as us not being subject to a material amount of entity-level taxation by individual states.purposes. If the Internal Revenue Service (IRS)we were to treat usbe treated as a corporation for U.S. federal income tax purposes, or if we were tootherwise become subject to a material amount of entity level taxation for U.S. federal, state and local tax purposes, then our cash available for distribution wouldto unitholders and the value of our common units could be substantially reduced.


The anticipated after-tax benefit of an investment in us depends largely on our classification as a partnership for U.S. federal income tax purposes.

Despite the fact that we are organized as a limited partnership under Delaware law, we would be treated as a corporation for U.S. federal income tax purposes unlessif the Internal Revenue Service (IRS) were to determine that we fail to satisfy a "qualifying income"“qualifying income” requirement. Based upon our

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current operations, we believe we satisfy the qualifying income requirement. We have not requested, and do not plan to request, a ruling from the IRS on this or any other tax matter affecting us. Failing to meet the qualifying income requirement or aany legislative, administrative or judicial change in current law could cause us to be treated as a corporation for U.S. federal income tax purposes or otherwise subject us to taxation as an entity.

at the entity level.

If we were treated as a corporation for U.S. federal income tax purposes, we would pay U.S. federal income taxes on our taxable income at the applicable corporate tax rate, and we would likely have to pay state income taxes at varying rates. Distributions to our unitholders (to the extent of our earnings and profits) would generally be taxed again to unitholders as corporate dividends, and no income, gains, losses, deductions or credits would flow through to our unitholders. BecauseIn the event of a tax imposed upon us as a corporation, the cash available for distribution to our unitholders wouldcould be substantially reduced. Any tax treatment of us as a corporation wouldreduced and result in a material reduction in the anticipated cash flow and after-tax return to unitholders, and thuswhich in turn would likely result inhave a substantial reduction innegative impact on the value of theour common units.

At the state level, several states have been evaluating ways to subject partnerships to entity-level taxation through the imposition of state income, franchise or other forms of taxation. Our Partnership Agreement provides that, if a law is enacted or existing law is modified or interpreted in a manner that subjects us to taxation as a corporation or otherwise subjects us to entity level taxation for U.S. federal, state, or local income tax purposes, then specified provisions of the Partnership Agreement relating to distributions will be subject to change. These changes would include a decrease in cash distributions to reflect the impact of that law on us.

unitholders.

The tax treatment of publicly traded partnerships or an investment in our units could be subject to potential legislative, judicial or administrative changes or differing interpretations, possibly applied on a retroactive basis.


The present U.S. federal income tax treatment of publicly traded partnerships, including us, or an investment in our common units, may be modified by administrative, legislative or judicial changes or differing interpretations at any time. From time to time, membersMembers of the U.S. Congress have frequently proposed and considered substantive changes to the existing U.S. federal income tax laws that would affect publicly traded partnerships, including proposals that would eliminate our ability to qualify for partnership tax treatment.
In addition, the Treasury Department has issued, and in the future may issue, regulations interpreting those laws that affect publicly traded partnerships. AlthoughThere can be no assurance that there is no current legislative proposal, a prior legislative proposal would have eliminated the qualifying income exception for all publicly traded partnerships upon which we rely for our treatment as a partnership forwill not be further changes to U.S. federal income tax purposes.

In addition, on January 24, 2017, final regulations (the Final Regulations) regarding which activities give rise tolaws or the Treasury Department’s interpretation of the qualifying income within the meaning of Section 7704 of the Internal Revenue Code of 1986, as amended (the Code) were publishedrules in the Federal Register. We do not believe the Final Regulations affecta manner that could impact our ability to be treatedqualify as a partnership for U.S. federalin the future. We believe the income tax purposes.

However, anythat we treat as qualifying satisfies the requirements under current regulations.

Any modification to the U.S. federal income tax laws may be applied retroactively and could make it more difficult or impossible for us to meet the exception for certain publicly traded partnerships to be treated as partnerships for U.S. federal income tax purposes. We are unable to predict whether any of these changes or other proposals will ultimately be enacted. Any suchfuture legislative changes could negatively impact the value of an investment in our common units.

Unitholders are urged to consult with tax advisors with respect to the status of regulatory or administrative developments and proposals and their potential effect on their investment in our common units.

If the IRS were to contest the federal income tax positions we take, it may adversely impact the market for our common units, and the costs of any such contest would reduce our cash available for distribution to our unitholders.


We have not requested a ruling from the IRS with respect to anyour treatment as a partnership for U.S. federal income tax matter affecting us.purposes. The IRS may adopt positions that differ from the positions we take. It may be necessary to resort to administrative or court proceedings in an effort to sustain some or all of the positions we take. Any contestA court may not agree with some or all of the IRS, and the outcome of anypositions we take. Any contest with the IRS may materially and adversely impact the market for our common units and the price at which the common unitsthey trade. In addition,
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Moreover, the costs of any contest withbetween us and the IRS will result in a reduction in our cash available for distribution to our unitholders and thus will be borne directly or indirectly by the unitholders and the General Partner.

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our unitholders.

If the IRS makes audit adjustments to our income tax returns for tax years beginning after December 31, 2017, it (and some states) may assess and collect any taxes (including any applicable penalties and interest) resulting from such audit adjustment directly from us, in which case our cash available for distribution to our unitholders might be substantially reduced and our current and former unitholders may be required to indemnify us for any taxes (including any applicable penalties and interest) resulting from such audit adjustments that were paid on such unitholders'unitholders’ behalf.


Pursuant to the Bipartisan Budget Act of 2015, for tax years beginning after December 31, 2017, if the IRS makes audit adjustments to our income tax returns, it (and some states) may assess and collect any taxes (including any applicable penalties and interest) resulting from such audit adjustment directly from us. Under our limited Partnership Agreement, our general partner is permitted to make elections under the new rules to either pay the taxes (including any applicable penalties and interest) directly to the IRS or, if we are eligible, issue a revised information statement to each unitholder and former unitholder with respect to an audited and adjusted return. Although our general partner may elect to have our unitholders and former unitholders take such audit adjustment into account and pay any resulting taxes (including applicable penalties or interest) in accordance with their interests in us during the tax year under audit, there can be no assurance that such election will be practical, permissible or effective in all circumstances. As a result, our current unitholders may bear some or all of the tax liability resulting from such audit adjustment, even if such unitholders did not own our common units in us during the tax year under audit. If, as a result of any such audit adjustment, we are required to make payments of taxes, penalties and interest, our cash available for distribution to our unitholders might be substantially reduced and our current and former unitholders may be required to indemnify us for any taxes (including any applicable penalties and interest) resulting from such audit adjustments that were paid on such unitholders'unitholders’ behalf. These rules are not applicable for tax years beginning on or prior to December 31, 2017.

Unitholders may be required to pay taxes on income from us even if they receive no cash distributions.


Because unitholders are treated as partners to whom we allocate taxable income which could be different in amount than the cash distributed, unitholders may be required to pay U.S. federal income taxes and, in some cases, state and local income taxes on their allocable share of our income, whether or not they receive cash distributions from us. Unitholders may not receive cash distributions equal to their allocable share of our taxable income or even the tax liability that results from that income.

Tax gains or losses on the disposition of common units could be different than expected.

If unitholders sell their common units, they will recognize a taxable gain or loss equal to the difference between the amount realized and their adjusted tax basis in those common units. Prior distributions in excess of the total net taxable income that a unitholder was allocated for a common unit, which distributions decreased the unitholder's tax basis in that common unit, will, in effect, become taxable income if the common unit is sold at a price greater than theirits adjusted tax basis in that common unit, even if the price is less than the original cost. A substantial portion of the amount realized on the sale of common units, whether or not representing a gain, may be ordinary income to unitholders due to certain items such as potential depreciation recapture. Thus, a unitholder may recognize both ordinary income and capital loss from the sale of units if the amount realized on a sale of such units is less than such unitholder’s adjusted basis in the units. Net capital loss may only offset capital gains and, in the case of individuals, up to $3,000 of ordinary income per year. In the taxable period in which a unitholder sells its units, such unitholder may recognize ordinary income from our allocations of income and gain to such unitholder prior to the sale and from recapture items that generally cannot be offset by any capital loss recognized upon the sale of units. If the IRS were to successfully contest some conventions we use, unitholders could recognize more taxable gain on the sale of common units than would be the case under those conventions without the benefit of decreased taxable income in prior years.

Unitholders may be subject to limitation on their ability to deduct interest expense incurred by us.


In general, our unitholders are entitled to a deduction for the interest we have paid or accrued on indebtedness properly allocable to our trade or business during our taxable year. However, subject to certain exceptions in the Coronavirus Aid, Relief, and Economic Security Act (the CARES Act, discussed below) under the 2017 Tax Act, for taxable years beginning after December 31, 2017, our deduction for "business interest" is“business interest” may be limited to the sum of our business interest income and 30% of our "adjusted“adjusted taxable income."” For the 2020 taxable year, the CARES Act generally increases the 30% adjusted taxable income limitation to 50%. For the purposes of this limitation, adjusted taxable income is computed without regard to any business interest expense or business interest income, and in the case of taxable years beginning before January 1, 2022, any deduction allowable for depreciation, amortization, or depletion. Althoughdepletion to the extent such depreciation, amortization or depletion is not capitalized into cost of goods sold with respect to inventory. The interest limitation does not apply to certain regulated pipeline businesses application ofand, therefore, we believe that our interest expense is fully deductible. If the interest limitation to tiered

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businesses like ours that hold interests in regulated businesses is not clear. PendingIRS contests this position or if further guidance specificis issued contrary to this issue, we are not able to determine the impactpositions taken, the limitation could have on our unitholders'unitholder’s ability to deduct ourthis interest expense but it is possible that our unitholders' interest expense deduction willcould be limited.


Tax-exempt entities face unique tax issues from owning our common units that may result in adverse tax consequences to them.


Investment in our common units by tax-exempt entities, such as employee benefit plans and individual retirement accounts (known as IRAs) raises issues unique to them. For example, virtually all of our income allocated to organizations that are exempt from U.S. federal income tax, including IRAs and other retirement plans, will be unrelated business taxable income and will be taxable to them. Further, with respect to taxable years beginning after December 31, 2017, a tax-exempt entity with more than one unrelated trade or business (including by attribution from investment in a partnership such as ours that is engaged in one or more unrelated trade or business) is required to compute the unrelated business taxable income of such tax-exempt entity separately with respect to each such trade or business (including for purposes of determining any net operating loss deduction). As a result, for years beginning after December 31, 2017, it may not be possible for tax-exempt entities to utilize losses from an investment in our partnership to offset unrelated business taxable income from another unrelated trade or business and vice versa. Tax-exempt entities should consult a tax advisor before investing in our common units.

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Non-U.S. Unitholdersunitholders will be subject to U.S. taxes and withholding with respect to their income and gain from owning our common units.


Non-U.S. unitholders are generally taxed and subject to income tax filing requirements by the United States on income effectively connected with a U.S. trade or business ("effectively connected income").business. Income allocated to our unitholders and any gain from the sale of our common units will generally be considered to be "effectively connected"“effectively connected” with a U.S. trade or business. As a result, distributions to a Non-U.S.non-U.S. unitholder will be subject to withholding at the highest applicable effective tax rate and a Non-U.S.non-U.S. unitholder who sells or otherwise disposes of a common unit will also be subject to U.S. federal income tax on the gain realized from the sale or disposition of that common unit.

The 2017 Tax Act imposes a withholding obligation of 10% of


Moreover, the amount realized upon a Non-U.S. unitholder's sale or exchangetransferee of an interest in a partnership that is engaged in a U.S. trade or business. However, duebusiness is generally required to challengeswithhold 10% of administeringthe amount realized by the transferor unless the transferor certifies that it is not a foreign person. While the determination of a partner’s amount realized generally includes any decrease of a partner’s share of the partnership’s liabilities, recently issued Treasury regulations provide that the “amount realized” on a transfer of an interest in a publicly traded partnership, such as our common units, will generally be the amount of gross proceeds paid to the broker effecting the applicable transfer on behalf of the transferor, and thus will be determined without regard to any decrease in that partner’s share of a publicly traded partnership’s liabilities. The Treasury regulations further provide that withholding obligation applicableon a transfer of an interest in a publicly traded partnership will not be imposed on a transfer that occurs prior to open market trading and other complications, the IRS has temporarily suspended the application of this withholding rule to open market transfersJanuary 1, 2022. For a transfer of interests in a publicly traded partnerships pending promulgation of regulationspartnership that is effected through a broker on or other guidance that resolvesafter January 1, 2022, the challenges. Itobligation to withhold is not clear if or when such regulations or other guidance will be issued. Non-U.S.imposed on the transferor’s broker. Prospective foreign unitholders should consult atheir tax advisor before investingadvisors regarding the impact of these rules on an investment in our common units.

We treat a purchaser of our common units as having the same tax benefits without regard to the actual common units purchased. The IRS may challenge this treatment, which could adversely affect the value of the common units.


Because we cannot match transferors and transferees of common units, we have adopted depreciation and amortization conventions that may not conform to all aspects of specified Treasury Regulations. A successful challenge to those conventions by the IRS could adversely affect the amount of tax benefits available to unitholders or could affect the timing of tax benefits or the amount of taxable gain from the sale of common units and could have a negative impact on the value of the common units or result in audit adjustments to unitholders'unitholders’ tax returns.

We generally prorate our items of income, gain, loss and deduction between transferors and transferees of our common units each month based upon the ownership of our common units on the first day of each month, instead of on

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the basis of the date a particular unit is transferred. The IRS may challenge this treatment, which could change the allocation of items of income, gain, loss and deduction among our unitholders.


We generally prorate our items of income, gain, loss and deduction between transferors and transferees of our common units each month based upon the ownership of our common units on the first day of each month (the Allocation Date), instead of on the basis of the date a particular unit is transferred. Similarly, we generally allocate certain deductions for depreciation of capital additions, gain or loss realized on a sale or other disposition of our assets and, in the discretion of the general partner, any other extraordinary item of income, gain, loss or deduction based upon ownership on the Allocation Date. Final Treasury Regulations allow a similar monthly simplifying convention, but such regulations do not specifically authorize all aspects of our proration method. If the IRS were to challenge our proration method, we may be required to change the allocation of items of income, gain, loss and deduction among our unitholders.

A unitholder whose common units are the subject of a securities loan (e.g., a loan to a "short seller"“short seller” to cover a short sale of units) may be considered to have disposed of those units. If so, he would no longer be treated for tax purposes as a partner with respect to those common units during the period of the loan and may recognize gain or loss from the disposition.


Because there are no specific rules governing the U.S. federal income tax consequence of loaning a partnership interest, a unitholder whose common units are the subject of a securities loan may be considered as having disposed of the loaned units. In that case, the unitholder may no longer be treated for tax purposes as a partner with respect to those common units during the period of the loan to the short seller and the unitholder may recognize gain or loss from such disposition. Moreover, during the period of the loan, any of our income, gain, loss or deduction with respect to those common units may not be reportable by the unitholder and any cash distributions received by the unitholder as to those common units could be fully taxable as ordinary income. Unitholders desiring to assure their status as partners and avoid the risk of gain recognition from a securities loan are urged to consult a tax advisor to determine whether it is advisable to modify any applicable brokerage account agreements to prohibit their brokers from borrowing their units.

We have adopted certain valuation methodologies that may result in a shift of income, gain, loss and deduction between the General Partner and the unitholders. The IRS may challenge this treatment, which could adversely affect the value of the common units.


In determining the items of income, gain, loss and deduction allocable to our unitholders, we must routinely determine the fair market value of our assets.

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Although we may, from time to time, consult with professional appraisers regarding valuation matters, we make many fair market value estimates using a methodology based on the market value of our common units as a means to measure the fair market value of our assets. The IRS may challenge these valuation methods and the resulting allocations of income, gain, loss and deduction.

Pursuant to the Bipartisan Budget Act of 2015, the IRS can isolate the resulting allocation adjustments that increase tax from those that decrease tax and assess tax at the partnership level, without netting the adjustments. Such a result would reduce the cash available for distribution by the partnership.

A successful IRS challenge to these methods, calculations or allocations could adversely affect the timing or amount of taxable income or loss being allocated to our unitholders. It also could affect the amount or character of taxable gain from our unitholders'unitholders’ sale of common units and could have a negative impact on the value of the common units or result in audit adjustments to our unitholders'unitholders’ tax returns without the benefit of additional deductions.

Unitholders will likely be subject to state and local taxes and return filing requirements in states where they do not live as a result of an investment in our common units.


In addition to U.S. federal income taxes, unitholders will likely be subject to other taxes, including state and local taxes, unincorporated business taxes and estate, inheritance or intangible taxes that are imposed by the various jurisdictions in which we do business or own property now or in the future, even if they do not live in any of those jurisdictions. We may be required to withhold income taxes with respect to income allocable or distributions made to our unitholders. In addition, unitholders may be required to file state and local income tax returns and pay state and local income taxes in

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some or all of the jurisdictions in which we do business or own property and may be subject to penalties for failure to comply with those requirements.

We currently own assets in multiple states. Manystates, many of these stateswhich currently impose a personal income tax on individuals. Generally, these states also impose income taxes on corporations and other entities. As we make acquisitions or expand our business, we may own assets or conduct business in additional states that impose a personal income tax. It is the unitholders' responsibility to file all required U.S. federal, state and local tax returns.

returns and pay any taxes due in these jurisdictions. Unitholders should consult with their own tax advisors regarding the filing of such tax returns, the payment of such taxes, and the deductibility of any taxes paid.

GENERAL RISKS RELATED TO THE PARTNERSHIP

We face various risks and uncertainties beyond our control, such as recent public health concerns related to the COVID-19 pandemic, which could have a materially adverse impact on our business, financial condition and results of operation.

On March 11, 2020, the WHO declared COVID-19, a global pandemic. In addition, the spread of the COVID-19 virus across the globe has impacted financial markets and global economic activity. These impacts include supply chain disruptions, massive unemployment and a decrease in commercial and industrial activity around the world. The impact of the COVID-19 pandemic, compounded by the recent collapse in crude oil markets, has resulted in significant market disruption.

Our ability to access the debt market or borrowings under our debt agreements to fund our significant capital expenditures could be negatively impacted due to uncertainty in the current market environment. The COVID-19 pandemic could also lead to a general slowdown in construction activities related to our capital projects. However, there is no information available at this time that would allow us to quantify the impact such delay may have on the completion of our capital projects. Finally, if COVID-19 were to impact a location where we have a high concentration of business and resources, our local workforce could be affected by such an occurrence or outbreak which could also significantly disrupt our operations and decrease our ability to service our customers.

While we have not seen any material impact of the COVID-19 pandemic on our business to date, it is difficult to predict how significant the impact of the COVID-19 virus, including any responses to it, will be on the global economy and our business or for how long any disruptions are likely to continue. The extent of such impact will depend on future developments, which are highly uncertain, including new information which may emerge concerning the severity of the COVID-19 pandemic and additional actions which may be taken to contain the further spread of the COVID-19 virus. Even after the COVID-19 pandemic has subsided, our business may be adversely impacted by the economic downturn or a recession that has occurred or may occur in the future. The COVID-19 pandemic could also increase or trigger other risks as discussed in detail in this section, any of which could have a materially adverse impact on our business, financial condition and results of operation.

Our pipeline systems’ business systems could be negatively impacted by security threats, including cyber security threats, and related disruptions.

Cyber-attacks are becoming more sophisticated, and U.S. government warnings have indicated that infrastructure assets, including pipelines, may be specifically targeted by certain groups. In fact, PHMSA has posted warnings to all pipeline owners and operators of the importance of safeguarding and securing their pipeline facilities and monitoring their supervisory control and data acquisition (SCADA) systems for abnormal operations and/or indications of unauthorized access or interference with safe pipeline operations based on recent incidents involving environmental activists.
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These potential security events might include our pipeline systems or operating systems and may result in damage to our pipeline facilities and affect our ability to operate or control our pipeline assets; their operations could be disrupted and/or customer information could be stolen.

We depend on the secure operation of our physical assets to transport the energy we deliver and our information technology to process, transmit and store electronic information, including information TC Energy uses to safely operate our pipeline systems. Security breaches could expose our business to a risk of loss, misuse or interruption of critical physical assets or information and functions that affect the pipeline operations. Such losses could result in operational impacts, damage to our assets, public or personnel safety incidents, damage to the environment, reputational harm, competitive disadvantage, regulatory enforcement actions, litigation and a potential material adverse effect on our operations, financial position and results of operations. There is no certainty that costs incurred related to securing against threats will be recovered through rates.

We are exposed to credit risk when a customer fails to perform its contractual obligations.

Our pipeline systems are subject to a risk of loss resulting from the nonperformance by a customer of its contractual obligations. Our exposure generally relates to receivables for services provided and future performance over the remaining contract terms under firm transportation contracts. Our pipelines’ FERC approved tariffs limit the amount of credit support that they may require in the event that a customer’s creditworthiness is or becomes unacceptable. If a significant customer has financial problems, which result in a delay or failure to pay for services provided by them or contracted for with them, it could have a material adverse effect on our business and results of operations.

Item 1B. Unresolved Staff Comments

None.

Item 2. Properties

We believe that we hold satisfactory rights, title

Please read Item 1. Business for a description of our principal physical properties and interests ina map showing the properties owned or used bylocations of our pipeline systems. With respect to real property, our pipeline systems own or lease sites for compressor stations, meter stations, pipeline field offices and microwave towers. Our pipeline systems are constructed and operated on landproperty owned by individuals, governmental authorities, Native American tribes (as further discussed below) and other third parties pursuant to leases, easements, rights-of-way, permits and licenses, the majority of which are perpetual. Our pipeline systems also own or lease land for compressor stations, meter stations and pipeline field offices. Certain land use rights, in particular rights-of-way on tribal land held in trust by the BIA, are subject to periodic renewal.renewal, periodic payments, encumbrances and/or restrictions. We believe that we generally have sufficient rights, title and interest in the properties needed to operate our pipeline systems' properties are adequatesystems and suitable forconduct our business and that such periodic renewals, rental payments, encumbrances and restrictions should not materially detract from the conductvalue of our pipeline systems or materially interfere with the operation of their business in the future.

Northern Border – Approximately 90 miles of our Northern Border pipeline system is located within the boundaries of the Fort Peck Indian Reservation in Montana. Northern Border has a pipeline right-of-way lease with the Assiniboine and Sioux Tribes of the Fort Peck Indian Reservation, the term of which expires in 2061. In conjunction with obtaining right-of-way access across tribal lands located within the exterior boundaries of the Fort Peck Indian Reservation, Northern Border also obtained right-of-way access across allotted lands located within the reservation boundaries. With the exception of one tract subjectbusiness.

See Part I, Item 1A “Risk Factors-Risks Related to a right-of-way grant expiring in 2035, the allotted lands are subjectOur Pipeline Systems” for further information regarding risks related to a perpetual easement granted by the Bureau of Indian Affairs (BIA) for and on behalf of the individual allottees.

Great Lakes – Approximately 74 miles of our Great Lakes pipeline system is located within the boundaries of three Indian reservations: the Leech Lake Reservation and the Fond du Lac Reservation in Minnesota, and the Bad River Reservation in Wisconsin. Great Lakes has right-of-way access across allotted and tribal lands located within each reservation's boundaries that expire in the second quarter of 2018. Great Lakes is in discussions with tribal authorities for the renewal of approximately 7.6 miles of rights-of-way access prior to their expiration. The Great Lakes pipeline also crosses approximately 1,000 feet in two tracts under perpetual easement located within the Chippewa Indian Reservation in Lower Michigan.

property rights.

Item 3. Legal Proceedings

We aremay be involved in various legal proceedings from time to time that arise in the ordinary course of business, as well as proceedings that we consider material under federal securities regulations.business. Information regarding our pipeline systems'systems’ rate proceedings is described in Item 1. "Business – Government Regulation – Regulatory and Rate Proceedings" is incorporated herein by reference. We are also a party to the followingInformation on our legal proceeding:

Great Lakes v. Essar Steel Minnesota LLC, et al.proceedings can be found under Note 2On October 29, 2009, Great Lakes filed suit in the U.S. District Court, District of Minnesota, against Essar Minnesota LLC (Essar Minnesota)Contingencies within Part IV, Item 15. “Exhibits and certain Foreign Essar Affiliates (collectively, Essar) for breach of its monthly payment obligation under its transportation services agreement with Great Lakes. Great Lakes sought to recover approximately $33 million for past and future payments due under the agreement. On September 16, 2015, following a jury trial, the federal district court judge entered a judgment in the amount of

42    TC PipeLines, LPAnnual Report2017



$32.9 million in favor of Great Lakes. On September 20, 2015, Essar appealed the decision to the United States Court of Appeals for the Eighth Circuit (Eighth Circuit) based on an allegation of improper jurisdiction and a number of other rulingsFinancial Statement Schedules,” which information is incorporated herein by the federal district judge. Essar was required to post a performance bond for the full value of the judgment pending appeal. The Eighth Circuit heard the appeal on October 20, 2016. A decision on the appeal was received in December 2016 and the Eighth Circuit vacated Great Lakes' judgment against Essar finding that there was no federal jurisdiction. Great Lakes filed a Request for Rehearing with the Eighth Circuit and it was denied in January 2017. Before the Circuit Court issued its decision, Essar Minnesota filed for bankruptcy in July 2016. The Foreign Essar Affiliates have not filed for bankruptcy. Following the Circuit Court's decision, the performance bond was released into the bankruptcy court proceedings. Great Lakes filed a claim against Essar Minnesota in the bankruptcy court and its case against the Foreign Essar Affiliates in Minnesota state court remains pending. In April 2017, after Great Lakes agreement with creditors on an allowed claim, the bankruptcy court approved Great Lakes' claim in the amount of $31.5 million. On May 20, 2017, the federal district court awarded Essar Minnesota approximately $1.2 million for costs, including recovery of the performance bond premium, to be paid by Great Lakes. Great Lakes filed a motion with the bankruptcy court to offset the $1.2 million award of costs against its claim against Essar Minnesota in the bankruptcy proceeding but was unsuccessful. As a result, Great Lakes accrued the $1.2 million in its books. Great Lakes is unable to estimate the timing or the extent to which its claim will be recoverable in the bankruptcy proceedings.

reference.

Item 4. Mine Safety Disclosures

None.

TC PipeLines, LPAnnual Report2017    43


PART II

Item 5.   Market for Registrant'sRegistrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

As of February 22, 2018,19, 2021, there were approximately 3526 holders of record of our common units. Our common units trade on the NYSE under the symbol "TCP".

“TCP.”

46     TC PipeLines, LP Annual Report 2020

Table of Contents
As of February 22, 2018,19, 2021, the Partnership had 71,306,396 common units outstanding, of which 54,221,565 were held by non-affiliates and 17,084,831 common units were held by subsidiaries of TransCanada,TC Energy, including 5,797,106 common units held by our General Partner. Additionally, TransCanada,TC Energy, through our General Partner, owns 100 percent of our IDRs and an effectivea two percent general partner interest in the Partnership. TransCanadaTC Energy also holds 100 percent of our 1,900,000 outstanding Class B units. There is no established public trading market for our IDRs and Class B units.

The following table sets forth, for the periods indicated, the high and low sale prices per common unit, as reported by the NYSE, and the amount of cash

Further details regarding our distributions declared per common unit with respect to the corresponding periods. Cash distributions are paid within 45 days after the end of each quarter to unitholders of record as of the record date.

  
Price Range

 Cash Distributions
Declared per
 
  High Low Common Unit 

2017       
First Quarter $65.03 $57.02 $0.94 
Second Quarter $61.74 $51.06 $1.00 
Third Quarter $59.30 $49.83 $1.00 
Fourth Quarter $55.59 $48.55 $1.00 

2016

 

 

 

 

 

 

 
First Quarter $55.00 $34.25 $0.89 
Second Quarter $60.48 $46.50 $0.94 
Third Quarter $58.66 $50.24 $0.94 
Fourth Quarter $59.12 $47.12 $0.94 

On February 13, 2018, we paid a cash distribution of $76 million to common unitholders and the General Partner, representing a cash distribution of $1.00 per common unit for the quarter ended December 31, 2017. The distribution was allocated in the following manner: $71 million to the common unitholders as of the close of business on February 2, 2018 (including approximately $17 million to TransCanada as holder of 17,084,831 common units), and $5 million to the General Partner, which included $2 million for its effective two percent general partner interest and $3 million for its IDRs. In 2017, the Partnership made cash distributions to common unitholders and the General Partner that amounted to $284 million compared to $250 million in 2016.

Cash Distribution Policy

Pursuant to the Partnership Agreement, the General Partner receives two percent of all cash distributions in regard to its general partner interest and is also entitled to incentive distributions as described below. The unitholders receive the remaining portion of the cash distribution. Our quarterly cash distributions to the unitholders comprise all of our Available Cash. Available Cash is defined in the Partnership Agreement and generally means, with respect to any quarter, all cash on hand at the end of a quarter less the amount of cash reserves that are necessary or appropriate, in the reasonable discretion of the General Partner, to:

provide for the proper conduct of our business (including reserves for future capital expenditures and anticipated credit needs);

comply with applicable laws or any debt instrument or other agreement to which we are subject; and

44    TC PipeLines, LPAnnual Report2017


provide funds for cash distributions to unitholders and the General Partner in respect of any one or more of the next four quarters.

Incentivecan be found under Note 14-Cash Distributions

The incentive distribution provisions of the Partnership Agreement provide that the General Partner receives 15 percent of quarterly amounts distributed in excess of $0.81 per common unit, and a maximum of 25 percent of quarterly amounts distributed in excess of $0.88 per common unit, provided the balance has been first distributed to unitholders on a pro rata basis. The amounts that trigger incentive distributions at various levels are subject to adjustment in certain events, as described in the Partnership Agreement.

Incentive distributions are paid to our General Partner if quarterly cash distributions on the common units exceed levels specified in the Partnership Agreement. See Part II, Item 7 "Management's Discussion and Analysis of Financial Condition and Results of Operations – Cash Distribution Policy of the Partnership" for further information regarding IDRs.

In 2017, we paid incentive distributions to our General Partner of approximately $10 million (2016 – $6 million).

Distributions to Class B units

On January 23, 2018, the board of directors of our General Partner declared distributions to Class B unitholders in the amount of $15 million which amount was paid on February 13, 2018. In 2017, the Class B distribution was $22 million. The Class B distribution represents an amount based upon 30 percent of GTN's distributable cash flow exceeding certain annual thresholds.

Please read Notes 7, 10, 13 and 14 within Part IV, Item 15. "Exhibits“Exhibits and Financial Statement Schedules" for more detailed disclosures on the Class B units.

Schedules,” which information is incorporated herein by reference.

Item 6. Selected Financial Data

The selected financial data should be read in conjunction with the financial statements, including the notes thereto, and Part II, Item 7. "Management's“Management’s Discussion and Analysis of Financial Condition and Results of Operations."

(millions of dollars, except per common unit amounts) 2017 2016(a) 2015(a) 2014(a) 2013(a)(b) 

 
Income Data (for the year ended December 31)         
Transmission revenues 422 426 417 410 410 
Equity earnings(c) 124 97 97 88 67 
Impairment of equity-method investment(d)   (199)  
Net income 263 263 58 241 221 
Net income (loss) attributable to controlling interests 252 248 37 195 174 
Basic and diluted net (loss) income per common unit $3.16 $3.21(e)$(0.03)(e)$2.67(e)$2.13(e)

 
Cash Flow Data (for the year ended December 31)         
Cash distribution declared per common unit $3.94 $3.71 $3.51 $3.33 $3.21 

 
Balance Sheet Data (at December 31)         
Total assets 3,559 3,354 3,459(f)3,802(f)3,867(f)
Long-term debt (including current maturities) 2,403 1,911 1,971(f)1,778(f)1,679(f)
Partners' equity 1,068 1,272 1,391 1,818 2,013 
(millions of dollars, except per common unit amounts)20202019201820172016(a)
Income Data (for the year ended December 31)
Transmission revenues399 403 549 (d)422 426 
Equity earnings(b)
170 160 173 124 97 
Impairment of goodwill(c)
  59 — — 
Impairment of long‑lived assets(d)
  537 — — 
Net income (loss)301 297 (165)263 263 
Net income (loss) attributable to controlling interests284 280 (182)252 248 
Basic and diluted net (loss) income per common unit$3.90 $3.74 $(2.68)$3.16 $3.21 (e)
Cash Flow Data (for the year ended December 31)
Cash distribution declared per common unit$2.60 $2.60 $2.60 $3.94 $3.71 
Balance Sheet Data (at December 31)
Total assets3,145 2,853 2,899 3,559 3,354 
Long‑term debt, net1,768 1,880 2,072 2,352 1,859 
Partners’ equity833 760 699 1,068 1,272 
(a)
Recast information to consolidate PNGTS for all periods presented as a result of an additional 11.81 percent in PNGTS that was acquired from a subsidiary of TransCanadaTC Energy on June 1, 2017. Prior to this transaction, the Partnership owned a 49.9 percent interest in PNGTS that was acquired from TransCanadaTC Energy on January 1, 2016. Please read Note 2 – Significant Accounting policies-Basis of Presentation section of the Notes to the Consolidated Financial Statements included in Part IV Item 15. "Exhibits and Financial Statement Schedules"

TC PipeLines, LPAnnual Report2017    45


(b)
Recast information to consolidate GTN and Bison for all periods presented as a result of additional 45 percent membership interests in each of GTN and Bison that were acquired from subsidiaries of TransCanada in 2013 resulting in a 70 percent ownership in each. Please read Note 2,Policies – Basis of Presentation section of the Notes to the Consolidated Financial Statements included in Part IV Item 15. "Exhibits“Exhibits and Financial Statement Schedules"

(c)
Schedules”.
(b)Equity earnings represent our share in investee'sinvestee’s earnings and do not include any impairment charge on our equity investments.

(d)
During the fourth quarter of 2015, we recognized an impairment charge on our investment in Great Lakes amounting to $199 million. No other impairment was recognized during the periods presented. The equity earnings as presented in 2015 did not include this impairment charge.
(c)Please read Note 5-Equity Investments,4 – Goodwill and Regulatory, Notes to the Consolidated Financial Statements included in Part IV Item 15. "Exhibits“Exhibits and Financial Statement Schedules"

Schedules” for more information.
(d)Please read Note 7 – Property, plant and Equipment, Notes to the Consolidated Financial Statements included in Part IV, Item 15. “Exhibits and Financial Statement Schedules” for more information.
(e)
Represents basic and diluted net income per common unit prior to recast.

(f)
As a resultrecast


TC PipeLines, LP Annual Report 2020     47

Table of the application of Accounting Standards Update (ASU) No. 2015-03 "Interest-Imputation of Interest" and similar to the presentation of debt discounts, debt issuance costs previously reported as other assets in the balance sheet were reclassified as an offset against their respective debt liabilities.Contents

Item 7. Management'sManagement’s Discussion and Analysis of Financial Condition and Results of Operations

Management's Discussion and Analysis (MD&A) is intended to give our unitholders an opportunity to view the Partnership through the eyes of our management. We have done so by providing management's current assessment of, and outlook of the business of the Partnership. This MD&A should be read in conjunction together with Part I Item 1. “Business” and the accompanying December 31, 20172020 audited financial statements and notes included in Part IV, within Item 15. "Exhibits“Exhibits and Financial Statement Schedules".Schedules.” Our discussion and analysis includes the following:

BASIS OF PRESENTATION;

EXECUTIVE OVERVIEW;

HOW WE EVALUATE OUR OPERATIONS;

RESULTS OF OPERATIONS;

LIQUIDITY AND CAPITAL RESOURCES;

CRITICAL ACCOUNTING ESTIMATES;

CONTINGENCIES; and

RELATED PARTY TRANSACTIONS.

BASIS OF PRESENTATION

See Note 2 of the Partnership's consolidated financial statements included in Part IV within Item 15. "Exhibits and Financial Statement Schedules", for important information on the content and comparability of our historical financial statements.

The initial acquisition of a 49.9 percent interest in PNGTS on January 1, 2016 and additional 11.81 percent on June 1, 2017 (collectively, the PNGTS Acquisitions) were accounted for as transaction between entities under common control, which are required to be accounted for as if the PNGTS Acquisitions had occurred at the beginning of the year, with financial statements for prior periods recast to furnish comparative information. Accordingly, the accompanying historical financial information has been recast, except net income (loss) per common unit, to consolidate PNGTS for all periods presented.

Also, on June 1, 2017, the Partnership acquired from subsidiaries of TransCanada a 49.34 percent interest in Iroquois (Refer to Note 7 of the Partnership's consolidated financial statements included in Part IV within Item 15. "Exhibits and Financial Statement Schedules"). This transaction was accounted prospectively and formed part of the accompanying financial information effective June 1, 2017.

46    TC PipeLines, LPAnnual Report2017


EXECUTIVE OVERVIEW

Net

Financial Performance Highlights
Our 2020 highlights are summarized as follows:
Generated net income attributable to controlling interests was $252of $284 million or $3.16$3.90 per common unit compared to $280 million or $3.74 per common unit in 20172019
Generated adjusted earnings of $284 million or $3.90 per common unit compared to income of $248$280 million or $3.21$3.74 per common unit in 2016. Net income attributable to controlling interests increased by $42019
Generated EBITDA and Adjusted EBITDA of $479 million and $488 million in 20172020, respectively compared to 2016. Cash$460 million and $517 million in 2019, respectively
Declared and paid cash distributions declaredtotaling $2.60 per common unit, increased by six percent from $3.71or $0.65 per quarter, for both 2020 and 2019
Generated Distributable Cash Flow of $255 million compared to $340 million in 2019
S&P and Moody's affirmed the Partnership's credit rating of BBB/Stable and Baa2/Stable, respectively

Please see the “How We Evaluate Our Operations" section for more information on our non-GAAP financial measures: EBITDA, Adjusted EBITDA, Adjusted earnings and Adjusted earnings per common unit in 2016 to $3.94 per common unit in 2017.

Our EBITDA increased by three percent to $445 million and Distributable cash flow decreased by one percent to $310 million. Please see "Non-GAAP Financial Measures: EBITDA, Adjusted EBITDA and Distributable Cash Flow"Flows.

Planned Merger with TC Energy
On December 14, 2020, the Partnership entered into the TC Energy Merger Agreement pursuant to which TC Energy will acquire all the outstanding common units of the Partnership not beneficially owned by TC Energy or its affiliates, in exchange for 0.70 TC Energy common share for each outstanding Partnership common unit.

The transaction is expected to close late in the first quarter of 2021 subject to the approval by the holders of a majority of outstanding common units of the Partnership and customary regulatory approvals. Upon closing, the Partnership will be an indirect, wholly-owned subsidiary of TC Energy and will cease to be a publicly traded master limited partnership.

(Please see also “Item 1. Business- Recent Business Developments” for more information.

Outlook of Our Business

TransCanada, the ultimate parent company of our General Partner, is currently advancing CAD $23 billion of near-term capital projects, together with a number of other larger, commercially secured initiatives. TransCanada continues to view us as a core element of its strategy and we continue to expect to play a meaningful role in funding a portion of TransCanada's near-term capital growth program depending on market conditions and TransCanada's financing needs.

Our focus remains on the optimization of our asset portfolio and may include organic growth over time. We will continue to advance business opportunities over time that fit within our geographic footprint and invest in the ongoing safe and reliable operations of our pipeline assets.

Over the near term, we expect our assets to perform consistently due to high contract levels, positive market fundamentals and regulatory stability. The recent long-term contract between Great Lakes and TransCanada provides long-term contract stability for Great Lakes. Other opportunities for recontracting and expansion exist throughout our portfolio, including further benefits on GTN from upstream debottlenecking activities on related TransCanada pipelines. Continued high rates of utilization of our pipelines may require somewhat higher levels of investment in maintenance compared to recent years, but we expect that these investments will be reflected in rates in future years.

)

HOW WE EVALUATE OUR OPERATIONS

We use certain non-GAAP financial measures that do not have any standardized meaning under GAAP as we believe they each enhance the understanding of our operating performance. We use the following non-GAAP financial measures:

EBITDA

We use EBITDA as an approximate measure of our operating cash flow and current operating profitability. It measures our earnings from our pipeline systems before certain expenses are deducted.


Adjusted EBITDA

Adjusted EBITDA is our EBITDA, less (1) earnings from our equity investments, plus (2) distributions from our equity investments, and plus or minus (3) certain non-recurring items (if any) that are significant but not reflective of our underlying operations (see also discussion below). We provide Adjusted EBITDA as an additional performance measure of the current operating profitability of our assets.
48     TC PipeLines, LP Annual Report 2020

Table of Contents
Adjusted EBITDA, Adjusted earningsEarnings and Adjusted earningsEarnings per common unit

During 2015, we have evaluated

The evaluation of our financial performance and position from the perspective of earnings, and EBITDA is inclusive of the following 2018 items which are one-time or non-cash in nature:
Bison’s contract termination proceeds amounting to $97 million recognized as revenue;
the $537 million impairment charge related to our investment in Great Lakes recognized during Bison’s remaining balance of property, plant and equipment; and
the fourth quarter 2015. $59 million impairment charge related to Tuscarora’s goodwill.
However, we do not believe itthis is not reflective of the results ofour underlying operations during the period.periods presented. Therefore, in 2015, we have presented Adjusted EBITDA, Adjusted earnings and Adjusted earnings per common unit as non-GAAP financial measures that excludedexclude the impact2018 impacts of the $199$596 million non-cash impairment charge.

Forcharges and the years ended December 31, 2017 and 2016, we do not have anyone-time $97 million revenue item relating to Bison’s contract terminations. We had no similar adjustments in EBITDA, earnings or earnings per common unit. Accordingly, for the years ended December 31, 20172020 and 2016, our EBITDA is the same as Adjusted EBITDA and our GAAP earnings and GAAP earnings per common unit were not adjusted.

TC PipeLines, LPAnnual Report2017    47


2019 periods.

Distributable Cash Flows

Total distributable cash flow and distributable cash flow provide measures of distributable cash generated during the current earnings period.

Our distributable cash flow includes Adjusted EBITDA and therefore excludes 2018’s $596 million non-cash impairment charges and the one-time $97 million revenue item from receipt of proceeds relating to Bison’s contract terminations.

Please see "Non-GAAP“Non-GAAP Financial Measures: EBITDA, Adjusted EBITDA and Distributable Cash Flow"Flow” for more information.

RESULTS OF OPERATIONS

The ownership interests we have in our pipeline assets were our only material sources of income during the periods presented. Therefore, our results of operations and cash flows were influenced by, and reflect the same factors that influenced, our pipeline systems.

Year Ended December 31, 20172020 Compared with the Year Ended December 31, 2016

(unaudited)
(millions of dollars, except per common unit amounts)
 2017 2016(a) $
Change(d)
 %
Change(c)
 

 
Transmission revenues 422 426 (4)(1)
Equity earnings 124 97 27 28 
Operating, maintenance and administrative (103)(92)(11)(12)
Depreciation (97)(96)(1)(1)
Financial charges and other (82)(71)(11)(15)

 
Net income before taxes 264 264   
Income taxes (1)(1)  

 
Net Income 263 263   

 
Net income attributable to non-controlling interests 11 15 4 27 

 
Net income attributable to controlling interests 252 248 4 2 

 
          

 
Net income per common unit 3.16 3.21(b)(0.05)(2)

 
2019
(unaudited)$%
(millions of dollars, except per common unit amounts)20202019
Change(b)
Change(b)
Transmission revenues399 403 (4)(1)
Equity earnings170 160 10 
Operating, maintenance and administrative(100)(105)
Depreciation(89)(78)(11)(14)
Financial charges and other(73)(83)10 12 
Net income (loss) before taxes307 297 10 
Income taxes(6)(7)*
Net income (loss)301 298 
Net income attributable to non‑controlling interests17 18 (1)(6)
Net income (loss) attributable to controlling interests284 280 
Adjusted earnings (a)
284 280 
Net income (loss) per common unit3.90 3.74 0.16 
Adjusted earnings per common unit (a)
3.90 3.74 0.16 
(a)
Financial information was recast to consolidate PNGTS for all periods presented. Please see "Basis of Presentation" section for more information.

(b)
Net incomeAdjusted earnings and Adjusted earnings per common unit priorare non-GAAP financial measures for which reconciliations to recast.

(c)
the appropriate GAAP measures are provided below.
(b)Positive number represents a favorable change; bracketed or negative number represents an unfavorable change.

Net

*    Change is greater than 100 percent.
For the year ended December 31, 2020, the Partnership generated net income attributable to controlling interests increased by $4and adjusted earnings of $284 million to $252 million in 2017 compared to $248$280 million for the same period in 2016,2019, resulting in a net income per common unit during the year of $3.16 after allocations$3.90 compared to the General Partner and to the Class B units. Overall, 2017 is comparable to 2016$3.74 per common unit in 2019. This increase was primarily due to the net effect of:

Transmission revenues - The $4 million decrease was largely the net result of the following:

Transmission

lower revenue on GTN due to (i) its scheduled 6.6 percent rate decrease effective January 1, 2020; (ii) lower discretionary services sold primarily due to moderate weather conditions in early 2020 compared to colder weather experienced in early 2019; (iii) additional sales in 2019 related to regional supply constraints from a force majeure event
TC PipeLines, LP Annual Report 2020     49

experienced by a neighboring pipeline that were not repeated in 2020; and (iv) lower opportunity for the sale of discretionary services given the increased natural gas storage injection rates upstream of GTN;
lower revenue on Tuscarora due to its scheduled 10.8 percent rate decrease effective August 1, 2019;
higher revenue at PNGTS as a result of new revenues – from its PXP Phase II and Westbrook XPress Phase I projects,     both of which entered into service in November 2019, and from PXP Phase III, which entered into service in November 2020 partially offset by lower discretionary services sold by PNGTS in 2020 compared to 2019 due to more moderate weather conditions in early 2020;
lower revenue from short-term discretionary services sold by North Baja; and
lower revenue on Bison as a result of the expiration of one of its legacy contracts at the end of January 2019.

Equity Earnings - The $4$10 million increase was largely due to the following
one time result of higher earnings from our equity investment in Northern Border primarily related to certain pre-arranged contracts with ONEOK Midstream entered into by Northern Border that resulted in incremental revenue on the pipeline during the third quarter of 2020. As noted under "Recent Business Developments" within Item 1, the pre-arranged contracts were cancelled by FERC effective October 15, 2020. The capacity was remarketed, and awarded under terms that approximate Northern Border’s maximum recourse rates, which are lower than the pre-arranged contract rates and more consistent with historical results; and
higher earnings from our equity investment in Great Lakes primarily due to lower operating costs associated with its compliance programs and a decrease in TC Energy's allocated personnel costs.
Operating, maintenance and administrative costs - The $5 million decrease was primarily due to lower contracted and discretionary revenues on PNGTS and lower transportation rates on Tuscarora as a result of the settlement reached with its customers effective August 1, 2016decrease in TC Energy's allocated costs related to personnel partially offset by higher discretionary revenues on short-term services sold byoperating costs related to our pipeline systems' compliance programs and costs incurred related to the planned TC Energy Merger.
Depreciation and amortization - The $11 million increase is related to increased maintenance capital expenditures at GTN and North Baja.

Equity earnings – negative salvage allowance recorded for PNGTS during the period.

Financial charges and other - The $27$10 million decrease was primarily attributable to the following:
generally lower weighted average interest costs despite an increase in our overall debt balance; and
higher AFUDC primarily due to continued spending on our expansion projects and higher maintenance capital spending.

Income Taxes - The $7 million increase was primarily due to the addition of equity earnings from Iroquois, effective June 1, 2017.

48    TC PipeLines, LPAnnual Report2017


Operating, maintenance and administrative costs – The $11 millionan increase was mainly attributable to higher pipeline integrity costs on GTN and overall higher allocated management and operational expenses on our pipeline systems as performed by TransCanada.

Financial charges and other – The $11 million increase was mainly attributable to additional borrowings to finance the 2017 Acquisition.

Net-income attributable to non-controlling interests – The Partnership had a net decrease amounting to $4 million primarilyin PNGTS' deferred taxes due to lower earnings from PNGTS as a result ofchange in New Hampshire's Business Profits Tax rate effective in 2021 and an increase in PNGTS' current income taxes due to its lower revenues.

higher net income before taxes.


Year Ended December 31, 20162019 Compared with the Year Ended December 31, 2015

(unaudited)
(millions of dollars, except per common unit amounts)
 2016(a) 2015(a) $
Change(d)
 %
Change(d)
 

 
Transmission revenues 426 417 9 2 
Equity earnings 97 97   
Impairment of equity-method investment  (199)199 100 
Operating, maintenance and administrative (92)(97)5 5 
Depreciation (96)(95)(1)(1)
Financial charges and other (71)(63)(8)13 

 
Net income before taxes 264 60 204 * 
Income taxes (1)(2)1 50 

 
Net Income 263 58 205 * 

 
Net income attributable to non-controlling interests 15 21 6 29 

 
Net income attributable to controlling interests 248 37 211 * 

 
Adjusted earnings(b) 248 236 12 5 
Net income (loss) per common unit(c) 3.21 (0.03)3.24 * 

 
Adjusted earnings per common unit(b) 3.21 3.03 0.18 6 

 
(a)
Financial information was recast to consolidate PNGTS. Please see "Basis2018
(unaudited)
(millions of dollars, except per common unit amounts)
20192018
$
Change(b)
%
Change(b)
Transmission revenues403 549 (146)(27)
Equity earnings160 173 (13)(8)
Impairment of long-lived assets (537)537 100 
Impairment of goodwill (59)59 100 
Operating, maintenance and administrative(105)(101)(4)(4)
Depreciation(78)(97)19 20 
Financial charges and other(83)(92)10 
Net income (loss) before taxes297 (164)461 *
Income taxes1 (1)*
Net income (loss)298 (165)463 *
Net income attributable to non‑controlling interests18 17 
Net income (loss) attributable to controlling interests280 (182)462 *
Adjusted earnings(a)
280 317 (37)(12)

Net income (loss) per common unit3.74 (2.68)6.42 *
Adjusted earnings per common unit(a)
3.74 4.18 (0.44)(11)
50     TC PipeLines, LP Annual Report 2020

Table of Presentation" section for more information.

(b)
Contents
(a)Adjusted earnings and Adjusted earnings per common unit are non-GAAP financial measures for which reconciliations to the appropriate GAAP measures are provided for below.

(c)
Net income (loss) per common unit prior to recast.

(d)
(b)Positive number represents a favorable change; bracketed or negative number represents an unfavorable change.

*
Change is greater than 100 percent.

Net

For the year ended December 31, 2019, the Partnership generated net income attributable to controlling interests increased by $211of $280 million to $248 million in 2016 compared to $37a loss of $182 million for the same period in 2015,2018, resulting in a net income per common unit during the year of $3.21 after allocations$3.74 compared to the General Partner and to the Class B units. This increasea loss $2.68. The loss in 2018 was primarily the result ofdue to the recognition of a $199non-cash impairments relating to Bison’s property, plant and equipment and Tuscarora’s goodwill partially offset by the $97 million non-cash impairment charge to our investmentrevenue proceeds from Bison’s contract terminations in Great Lakes inthe fourth quarter 2015 which lowered our net income attributable to controlling interests in 2015. (Seeof 2018. See Part II, Item 7. "Management’s Discussion and Analysis of Financial Condition and Results of Operations – Critical Accounting Estimates – Impairment of Equity Investments, Goodwill, and Long-Lived Assets and Equity InvestmentsInvestments" section for more information.)

TC PipeLines, LPAnnual Report2017    49


The Partnership's details.

Adjusted earnings were higherwas lower by $12$37 million in 2016 compared to 2015, an increasefor the year ended December 31, 2019, a decrease of $0.18$0.44 per common unit mainly due to the following:

Transmission revenues – increase of $9 millionunit. This decrease was primarily due to the net effect of:

higher discretionary
Transmission revenues – Excluding the non-recurring $97 million revenue proceeds from Bison’s contract terminations in 2018 noted above, revenues for 2019 were lower by $49 million due largely to the decrease in revenue from Bison. As a result of early contract pay out, Bison was only approximately 40 percent contracted beginning in 2019 compared to 100 percent contracted in 2018, resulting in decreased revenue of approximately $48 million.
Revenue from GTN, North Baja, Tuscarora and PNGTS was largely comparable to prior year. The scheduled rate decreases on GTN from short-term services sold to its customers;

lower discretionary revenues on PNGTS from short-term services sold to its customers;

full year of revenues from GTN's Carty lateral system which was placed into service in October 2015; and

lower transportation rates on GTNour pipelines as a result of the settlement reached with its customers effective July 1, 2015.

Operating, maintenance and administrative – generally lower expenses in 20162018 FERC Actions were primarily offset by increased discretionary revenue as a result of lower operational costs onstrong natural gas flows mainly out of WCSB and solid contracting across our consolidated entities. Additionally, dropdown costs were incurred in 2015 related to the acquisition of the initial 49.9 percent interest in PNGTS.

Financial charges and otherConsolidated Subsidiaries. See also Part I, Item 1. “Business$8Government Regulations – 2018 FERC Actions.”

Equity Earnings – The $13 million increasedecrease was primarily due to the net effect of:

additional borrowings to fund a portion of our recent acquisitions

the following:
lower interest incurred by PNGTSdecrease in Iroquois’ equity earnings as a result of a decrease in its 2016 principal payments onrevenue. The sustained cold temperatures in the first quarter of 2018 resulted in incremental seasonal winter sales that were not achieved in the same period of 2019. Additionally, a scheduled reduction of Iroquois’ existing rates as part of the 2019 Iroquois Settlement went into effect; and
decrease in Great Lakes’ equity earnings as a result of a decrease in its long term debt

no interestrevenue and increase in its operating costs. The sustained cold temperatures in the first quarter of 2018 resulted in incremental seasonal winter sales for Great Lakes that were not achieved in the same period of 2019. Additionally, there was incurredan increase in 2016 on PNGTS' rate refund liability dueits operating costs related to the payment of all of PNGTS' outstanding rate refund liability on April 15, 2015. (Referits compliance programs, estimated costs related to Note 2right-of-way renewals and an increase in TC Energy's allocated management and corporate support functions expenses and common costs such as insurance.
Operation and maintenance expensesSignificant Accounting Policies – Revenue Recognition section, Notes to Consolidated Financial Statements includedThe increase in Part IV within Item 15. "Exhibitsoperation and Financial Statement Schedules")

Net income attributable to non-controlling interests – $6 million decreasemaintenance expenses was primarily due to the Partnership's 100 percent ownershipoverall net impact of the following:

increase in GTN effective April 1, 2015.

operational costs related to our pipeline systems' compliance programs;

increase in TC Energy's allocated costs related to corporate support functions and common costs such as insurance; and
decrease in overall property taxes primarily due to lower taxes assessed on Bison.
Depreciation – The decrease in depreciation expense in 2019 was a direct result of the long-lived asset impairment recognized during the fourth quarter of 2018 on Bison which effectively eliminated the depreciable base of the pipeline.
Financial charges and other – The $9 million decrease in financial charges and other expenses was primarily attributable to the repayment of our $170 million Term Loan during the fourth quarter of 2018 and repayment of borrowings under our Senior Credit Facility during the first quarter of 2019.
Non-GAAP Financial Measures: Adjusted earnings and Adjusted earnings per common unit

Reconciliation of Net income attributable to controlling interests to Adjusted earnings

(millions of dollars)
Year ended December 31
 2017 2016 2015

Net income attributable to controlling interests 252 248 37
 Add: Impairment of equity-method investment   199

Adjusted earnings 252 248 236

Reconciliation of Net income per common unit to Adjusted earnings per common unit

Year ended December 31 2017 2016 2015 

 
Net income (loss) per common unit-basic and diluted(b) 3.16 3.21(a)(0.03)(a)
 Add: per unit impact of impairment of equity-method investment(c)   3.06 

 
Adjusted earnings per common unit 3.16 3.21 3.03 

 
(a)
Net income per common unit prior to recast.

50    

Reconciliation of Net income (loss) attributable to controlling interests to Adjusted earnings
(millions of dollars)
Year ended December 31202020192018
Net income attributable to controlling interests284 280 (182)
Add: Impairment of goodwill — 59 
Add: Impairment of long-lived assets — 537 
Less: Revenue proceeds from Bison’s contract terminations — (97)
Adjusted earnings284 280 317 
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 2020     51

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(b)
Reconciliation of Net income (loss) per common unit to Adjusted earnings per common unit
Year ended December 31202020192018
Net income (loss) per common unit ‑ basic and diluted(a)
3.90 3.74 (2.68)
Add: per unit impact of impairment of goodwill — 0.81 (b)
Add: per unit impact of impairment of long-lived assets — 7.38 (c)
Less: per unit impact of revenue proceeds from Bison’s contract terminations — (1.33)(d)
Adjusted earnings per common unit3.90 3.74 4.18 
(a)See also Note 1314 of the Partnership'sPartnership’s consolidated financial statements included in Part IV. Item 15. 'Exhibits"Exhibits and Financial Statement Schedules"Schedules” for details of the calculation of net income (loss) per common unit.

(c)
(b)Computed by dividing the $199$59 million impairment charge, after deduction of amounts attributable to the General Partner with respect to its effective two percent interest, by the weighted average number of common units outstanding during the period.

(c)Computed by dividing the $537 million impairment charge, after deduction of amounts attributable to the General Partner with respect to its two percent interest, by the weighted average number of common units outstanding during the period.
(d)Computed by dividing the $97 million revenue, after deduction of amounts attributable to the General Partner with respect to its two percent interest, by the weighted average number of common units outstanding during the period.
LIQUIDITY AND CAPITAL RESOURCES

Overview

The Partnership strives to maintain financial strength and flexibility in all parts of the economic cycle. Our principal sources of liquidity and cash flows currently include distributions received from our equity investments, operating cash flows from our subsidiaries public offerings of debt and equity, term loans and our bank credit facility.facilities. The Partnership funds its operating expenses, debt service and cash distributions (including those distributions made to TransCanadaTC Energy through our General Partner and as holder of all our Class B units) primarily withfrom operating cash flow. Long-term capital needs may be met through the issuance of
Overall Current Financial Condition
Cash and Debt position - Our overall long-term debt balance increased by approximately $188 million primarily as result of the financing put in place during the period for our expansion projects. The increase included an excess $20 million of liquidity from utilization of PNGTS's revolving credit facility during the fourth quarter to fund forecasted capital spending on Westbrook XPress.
The $20 million excess liquidity as noted above, together with the $24 million return of capital special distribution we received during the third quarter from Iroquois representing our 49.34% share of the reimbursement proceeds received by Iroquois from its terminated Wright Interconnect Project, and net excess cash generated by our solid operating cash flows resulted in an increase in the balance of our cash and cash equivalents to $200 million at December 31, 2020 compared to our position at December 31, 2019 of approximately $83 million.
Working capital position - At December 31, 2020, our current assets totaled $257 million and current liabilities amounted to $487 million, leaving us with a working capital deficit of $230 million compared to a deficit of $14 million at December 31, 2019. Our working capital deficiency is considered normal course for our business and is managed through:
our ability to generate predictable and growing cash flows from operations;
cash on hand and full access to our $500 million Senior Credit Facility; and
our access to debt capital markets, facilitated by our strong investment grade ratings, allowing us the ability to renew and/or equity. Overall,refinance the current portion of our long-term debt.
We continue to be financially disciplined by using our available cash to fund ongoing capital expenditures and maintaining debt at prudent levels and we believe that our pipeline systems' ability to obtain financing at reasonable rates, together with a history of consistent cash flow from operating activities, provide a solid foundation to meet future liquidity and capital requirements. We expect to be ablewe are well positioned to fund our liquidity and capital resource requirements, includingobligations as required.
We believe our distributions and required debt repayments, at the Partnership level over the next 12 months utilizing our(1) cash flow and, if required, our existing Senior Credit Facility. The following table sets forth theon hand, (2) operating cash-flows, (3) $500 million available borrowing capacity under the Partnership'sour Senior Credit Facility:

(unaudited)
(millions of dollars)
December 31
 2017 2016 2015

Total capacity under the Senior Credit Facility 500 500 500
 Less: Outstanding borrowings under the Senior Credit Facility 185 160 200

Available capacity under the Senior Credit Facility 315 340 300

Facility at February 24, 2021 and (4) if needed, subject to customary lender approval upon request, an additional $500 million capacity that is available under the Senior Credit Facility's accordion feature, are sufficient to fund our short-term liquidity requirements, including distributions to our unitholders, ongoing capital expenditures, required debt repayments and other financing needs such as capital contribution requests from our equity investments without the need for additional common equity.

Our Pipeline Systems' Current Financial Condition
The Partnership's source of operating cashflows emanates from (1) operating cash generated by GTN, North Baja, Tuscarora, PNGTS and Bison, our consolidated subsidiaries, and (2) distributions received from our equity investments in Great Lakes, Northern Border and Iroquois.
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Our pipeline systems'systems’ principal sources of liquidity are cash generated from operating activities, long-term debt offerings, bank credit facilities and equity contributions from their owners. OurExcept as noted below, our pipeline systems have historically fundedexpect to fund their respective expansion projects primarily with debt. Except as noted below, our pipeline systems' normal recurring operating expenses, maintenance capital expenditures, debt service and cash distributions toare primarily funded with their owners primarily with operating cash flow. However, sinceflows.

Since the fourth quarter of 2010, however, Great Lakes has funded its debt repayments with cash calls to its owners. Additionally, on September 1, 2017,owners and we have contributed approximately $10 million each for 2020 and 2019 and $9 million for 2018.
In December 2020 and August 2019, the Partnership made an equity contribution to Northern BorderIroquois of $83 million.approximately $2 million and $4 million, respectively. This amount representsrepresented the Partnership's 50Partnership’s 49.34 percent share of a onecash call from Iroquois to cover costs of regulatory approvals related to their ExC Project.
From time $166 millionto time, Northern Border requests equity contributions from or makes returns of capital contribution requestdistributions to its partners to manage its preferred capitalization levels. In June 2019, we received a return of capital distribution from Northern Border amounting to reduce$50 million and used those proceeds to partially repay our 2013 Term Loan Facility due in 2021.
Bison’s remaining contracts continued in effect until January of 2021. In 2019 and 2020, Bison generated revenues of $32 million and $31 million, respectively. We continue to explore alternative transportation-related options for Bison and we believe commercial potential exists to allow for the outstanding balanceflow of its revolver debtnatural gas on Bison in both directions, with the southwest direction involving deliveries onto third party pipelines and ultimately connecting into the Cheyenne hub. In any event, Bison will continue to increase its available borrowing capacity.

Capitalincur costs related to property tax and operating and maintenance costs of approximately $6 million per year.


Maintenance and expansion capital expenditures are funded by a variety of sources, including cash generated from operating activities, borrowings under bank credit facilities, issuance of senior unsecured notes or equity contributions from our pipeline systems' owners.as noted above. The ability of our pipeline systems to access the debt capital markets under reasonable terms depends onupon their financial positioncondition and generalprevailing market conditions.


The Partnership'sPartnership’s pipeline systems monitor the creditworthiness of their customers and have credit provisions included in their tariffs which, although limitedgoverned by FERC, allow them to request a certain amount of credit support as circumstances dictate.

TC PipeLines, LPAnnual Report2017    51


Summarized Cash Flow

Year Ended December 31,
(millions of dollars)
 2017 2016(a) 2015(a) 

 
Net cash provided by (used in):       
 Operating activities 376 417 260 
 Investing activities (761)(230)(326)
 Financing activities 354 (178)(32)

 
Net increase in cash and cash equivalents (31)9 (98)
Cash and cash equivalents at beginning of the period 64 55 153 

 
Cash and cash equivalents at end of the period 33 64 55 

 
(a)
Financial information was recast to consolidate PNGTS. Please see "Basis of Presentation" section for more information.

Year Ended December 31,
(millions of dollars)
202020192018
Net cash provided by (used in):
Operating activities413 412 540 
Investing activities(262)(32)(35)
Financing activities(34)(330)(505)
Net increase in cash and cash equivalents117 50 — 
Cash and cash equivalents at beginning of the period83 33 33 
Cash and cash equivalents at end of the period200 83 33 
Cash Flow Analysis for the Year Ended December 31, 20172020 compared to Same Period in 2016

2019

Operating Cash Flows

Net cash provided


The Partnership's operating cashflows for the twelve months ended December 31, 2020 compared to the same period in 2019 were comparable primarily due to the net effect of the positive impact of certain working capital items offset by a slight decrease in distributions received from operating activities decreasedof equity investments. The slight decrease in distributions from operating activities of equity investments was due to the net impact of the following:

no distributions from Great Lakes during the third quarter as it used the cash it generated during that period to fund a one-time commercial IT system purchase from a TC Energy affiliate on August 1, 2020; and

the timing of receipt of Iroquois' third quarter 2019 distributions from its operating activities, which we would ordinarily have received during the fourth quarter of 2019 but were instead received early in the first quarter of 2020, offset by $41additional surplus cash distribution received from Iroquois in the third quarter of 2019 as a result of the cash it accumulated during the previous year's earnings.
Investing Cash Flows

During the twelve months ended December 31, 2020, the Partnership’s cash used in our investing activities increase by $230 million compared to the same period in 2019 primarily due to the net impact of the following:
higher maintenance capital expenditures at GTN for its overhaul projects together with continued capital spending on our GTN XPress, PXP and Westbrook XPress projects;
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$29 million return of capital distribution received from Iroquois, compared to only $8 million in 2019, primarily due to the $24 million extra distribution we received in 2020 representing our 49.34% share of the reimbursement proceeds received by Iroquois from the termination of its Wright Interconnect Project; and
$50 million distribution received from Northern Border during the second quarter of 2019 that was considered a return of investment.
Financing Cash Flows

The change in cash used for financing activities was primarily due to the net debt issuance of $186 million in the twelve months ended December 31, 20172020 compared to a net debt repayment of $106 million for the same period in 2016 primarily due to:

lower cash generated from operating activities of our subsidiaries primarilythe prior year, largely due to its lower revenues and higher operating costs as discussed in "Results of Operations" section;

higher financing costs incurred as a result ofexecuted for the 2017 Acquisition; and

lower distributions from Great Lakes and Northern Border in 2017 partially offset by distributions received from Iroquois, resulting from the addition of Iroquois to our portfolio of assets effective June 1, 2017. Distributions received in the first quarter of 2016 from Great Lakes were higher than distributions received in the first quarter of 2017 on a run-rate basis due to the resolution of certain regulatory proceedings in the fourth quarter of 2015 which inflated its results during that period and resulted in higher cash flow. The increase in cash flow was paid to the Partnership in the first quarter of 2016 and was not applicable in the first quarter of 2017. Additionally, the Partnership received lower distributions from Northern Border in 2017 compared to the same period in 2016 primarily due to higher maintenance capital expenditures during the current 2017 period together with the change in Northern Border's distribution policy during 2016 from a lagged quarterly distribution to a more timely monthly distribution that resulted in a larger distribution in the second quarter of 2016.

Investing Cash Flows

Net cash used in investing activities increased by $531 million in the twelve months ended December 31, 2017 compared to the same period in 2016. On June 1, 2017, we invested $593 million to acquire a 49.34 percent interest in Iroquoison our GTN XPress, PXP and $53 million to acquire an additional 11.81 percent of PNGTS. Additionally, on September 1, 2017, we contributed $83 million to Northern Border representing our 50 percent share of a requested capital contribution to reduce the outstanding balance of its revolving credit facility. During 2017, we also received a $5 million distribution from Iroquois as a return of surplus cash on their balance sheet. Together, these transactions resulted in the net increase of $531 million compared to 2016 where we invested $193 million on January 1, 2016 to acquire a 49.9 percent interest in PNGTS.

Financing Cash Flows

The net change in cash from our financing activities was approximately $532 million in the twelve months ended December 31, 2017 compared to the same period in 2016 primarily due to the net effect of:

$552 million increase in net issuances of debt in 2017 primarily to finance the 2017 Acquisition;

$34 million increase in distributions paid to our common units and to our General Partner in respect of its two percent general partner interest and IDRs;

52    TC PipeLines, LPAnnual Report2017


$10 million increase in distributions paid to Class B units in 2017 as compared to 2016;

$9 million increase in our At-the-market (ATM) equity issuances in 2017 as compared to 2016;

$7 million decrease in distributions paid to non-controlling interest due to lower revenues on PNGTS compared to the previous periods; and

$8 million decrease in distributions paid to TransCanada as the former parent of PNGTS primarily due to the Partnership's acquisition of a 49.9 percent interest in PNGTS effective January 1, 2016 and additional 11.81 percent effective June 1, 2017.

Westbrook XPress expansion projects.

Cash Flow Analysis for the Year Ended December 31, 20162019 compared to Same Period in 2015

2018

Operating Cash Flows

Net

In the twelve months ended December 31, 2019, the Partnership's net cash provided by operating activities increaseddecreased by $157$128 million compared to the same period in 2018 primarily due to the net effect of:
lower net cash flow from operations of our Consolidated Subsidiaries due to lower revenue from Bison as a result of the contract terminations in 2018 (60 percent of Bison contracts bought out in 2018) and an overall increase in our operating expenses as discussed in more detail in “Results of Operations” above; and
increase in distributions received from operating activities of equity investments primarily as a result of:
lower maintenance capital spending during 2019 on Northern Border; and
an increase in distributions from Iroquois related to an increase in its cash generated from strong discretionary revenues in prior years.
Investing Cash Flows
During the twelve months ended December 31, 2019, the Partnership’s cash used in our investing activities decreased by $3 million compared to the same period in 2018 primarily due to the net impact of the following:
higher maintenance capital expenditures on GTN for major compressor equipment overhauls and pipe integrity projects, initial spending on our GTN XPress Project and continued capital spending on our PXP and Westbrook XPress projects and other growth projects;
equity contribution to Iroquois of approximately $4 million representing the Partnership’s 49.34 percent share of a $7 million capital call from Iroquois to cover costs of regulatory approvals related to their capital project; and
$50 million distribution received from Northern Border that was considered a return of investment during the second quarter of 2019.
Financing Cash Flows
The Partnership's net cash used for financing activities was $175 million lower in the twelve months ended December 31, 20162019 compared to the same period in 20152018 primarily due to the net effect of:

higher earnings as discussed$191 million decrease in more detailnet debt repayments;
$29 million decrease in the "Results of Operations" section.

higher distributed earnings received from equity investments in 2016distributions paid to common unitholders as a result of additional revenues from new contracts with ANR Pipeline Company (ANR), a related party

payment of all of PNGTS' outstanding rate refund liabilitylower per unit declaration beginning in 2015, including interest as a result of its rate case settlement approved by FERC on February 2015. Total refunds accumulated to $114 million, including $8 million of interest, and were paid to customers on April 15, 2015. (Refer to Note 2 – Significant Accounting Policies – Revenue Recognition section, Notes to Consolidated Financial Statements includedsecond quarter 2018 in Part IV within Item 15. "Exhibits and Financial Statement Schedules") and

timing of working capital changes. The majority of the timing impact relatesresponse to the settlement of our accounts payable and accrued liabilities.

Investing Cash Flows

Net cash used in investing activities decreased by $96 million in the twelve months ended December 31, 2016 compared to the same period in 2015 as we invested a lesser amount on our initial 49.9 percent acquisition of interest in PNGTS compared to our investment during the same period in 2015. In 2015, we paid $264 million to acquire the remaining 30 percent interest in GTN compared to $193 million paid for the acquisition of a 49.9 percent interest in PNGTS in 2016. Additionally, we had higher capital expenditures in 2015 due to expenditures related to the construction of the Carty Lateral.

Financing Cash Flows

Net cash used in financing activities increased by $146 million in the twelve months ended December 31, 2016 compared to the same period in 2015 primarily due to the net effect of:

2018 FERC Actions;
$254 million decrease in net issuances of debt in 2016 as compared with 2015;

$123 million increase in our ATM equity issuances in 2016 as compared with 2015;

$228 million increase in distributions paid to our common units including our General Partner's effective two percent share and its related IDRs;

non-controlling interests during 2019 as a result of increased income generated by PNGTS;
$122 million ofdecrease in distributions paid to Class B units in 2016;

2019 as compared to 2018; and
$940 million decrease in distributions paid to non-controlling interest due to the Partnership's 100 percent ownershipcash from equity issuances in GTN effective April 1, 2015; and

$10 million decrease in distributions paid to TransCanada2019 as the former parentAt-the-market Equity Issuance program (ATM program) was suspended during the first quarter of PNGTS due to the Partnership's acquisition of a 49.9 percent interest in PNGTS effective January 1, 2016.

TC PipeLines, LPAnnual Report2017    53


2018.

Capital spending

The Partnership'sPartnership’s share in capital spending for maintenance of existing facilities and growth projects was as follows:

Year Ended December 31
(millions of dollars)
(unaudited)
 2017 2016(a) 2015(a)

Maintenance 63 31 21
Growth 3 5 54

Total(b) 66 36 75

(a)
Financial information was recast to reflect our 61.71 percent share
54     TC PipeLines, LP Annual Report 2020

Table of PNGTS' capital spending for all periods presented however, PNGTS did not incur significant capital expenditures in 2016 and 2015. Please see "Basis of Presentation" section for more information.

(b)
Contents
Year Ended December 31
(millions of dollars)
(unaudited)202020192018
Maintenance156 76 60 
Growth165 26 
Total(a)
321 102 67 
(a)Total maintenance and growth capital expenditures as reflected in this table include AFUDC and amounts attributable to the Partnership'sPartnership’s proportionate share of maintenance and growth capital expenditures of the Partnership'sPartnership’s equity investments, which are not reflected in our total capital expenditures as presented in our consolidated statement of cash flows. Additionally, our proportionate share includes accrued capital expenditures during the period.

Year Ended December 31, 20172020 Compared with the Year Ended December 31, 2016

2019


Maintenance capital spending increased by $32$80 million in 20172020 compared to 20162019 mainly due to overhaulsincreased normal-course maintenance spending at GTN along with the one-time purchase of a commercial IT system by several of our pipelines. The increased maintenance capex at GTN on its compressor fleet resulted from higher throughput, operating hours and pipeline integrity projects on GTN in addition to continuingstrong demand for natural gas transportation. Additionally, there were also higher normal course compressor station overhauls that began in 2016overhaul spending on Northern Border.

The commercial IT system purchase will reduce future operating costs and overall, these maintenance capital expenditures will increase our pipelines’ respective rate bases and we anticipate will generate a return on and of capital in future rates.


Capital expenditures on growth projects were comparableincreased by $140 million between 20172020 and 2016.

2019 due to our continued spending on PXP and initial costs incurred on our GTN XPress, Iroquois’ ExC and Westbrook XPress projects.


Year Ended December 31, 20162019 Compared with the Year Ended December 31, 2015

2018


Maintenance capital spending increased by $10$16 million in 20162019 compared to 20152018 mainly due to increases in major equipment overhauls conducted in 2016and pipe integrity projects on GTN, as a result of higher transportation volumes of natural gas during the year. The higher maintenance projects costs were offset by lower compressor overhaul spending on Northern Border and Great Lakes andBorder. Additionally, in 2018, PNGTS incurred costs relatedon upgrading one of its existing meter communication systems to pipe integrity on Great Lakes and North Baja.

In 2015, The Partnership incurred significant spending related to the construction of Carty Lateral.meet current commercial pressure obligations. No such significant project occurred in 2016.

2019.

Capital expenditures on growth projects increased by $19 million between 2018 and 2019 due to our continued spending on PXP and initial costs incurred on our GTN XPress, Iroquois’ ExC and Westbrook XPress projects.
Cash Flow Outlook

Operating Cash Flow Outlook

During the first quarter of 2021, the Partnership received or expects to receive the following distributions from our equity investments:
Northern Border declared its December 20172020 distribution of $15$16 million on January 8, 2018,15, 2021, of which the Partnership received its 50 percent share or $7$8 million on January 31, 2018.

29, 2021.

Northern Border declared its January 20182021 distribution of $17$18 million on February 14, 2018,16, 2021, of which the Partnership will receive its 50 percent share or $9 million on February 28, 2018.

26, 2021.

Great Lakes declared its fourth quarter 20172020 distribution of $20$23 million on January 10, 2018,13, 2021, of which the Partnership received its 46.45 percent share or $9$11 million on February 1, 2018.

January 29, 2021.

Iroquois declared its fourth quarter 20172020 distribution of $29$22 million on January 22, 2018,February 18, 2021, of which the Partnership receivedwill receive its 49.34 percent share or $14$11 million on February 1, 2018.

March 24, 2021.

Investing Cash Flow Outlook

The Partnership expects to make a $9$14 million contribution in 20182021 to Great Lakes to fund debt repayments of Great Lakes which is consistent with prior years.

54    TC PipeLines, LPAnnual Report2017


The Partnership expects to make a $4 million contribution in 2021 to Iroquois to fund growth projects.

The Partnership expects to make a $4 million contribution in 2021 to Iroquois, representing our 49.34 percent share of a cash call from Iroquois to cover capital costs required on their Exc Project.
In 2018,2021, our pipeline systems expect to invest approximately $76$145 million in maintenance ofcapital for existing facilities, of which the Partnership’s share will be $109 million. The Partnership’s estimated capital maintenance costs do not include any costs related to our GTN XPress Project (see further discussion below). Maintenance capital expenditures are added to our pipelines’ respective rate bases and are expected to earn a return on and of capital over time through the regulatory rate-making process.
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Our pipeline systems also expect to invest approximately $27$306 million in growth projects in 2021, of which the Partnership'sPartnership’s share wouldwill be $53$265 million. 2021 growth capital expenditures will include an estimated $145 million of Phase I GTN XPress Project costs, which are reliability and horsepower replacement expenditures expected to be fully recoverable in GTN’s recourse rates commencing in 2022, along with other ongoing growth projects as discussed in Part 1, Item 1. “Business - Recent Business Developments.” As of December 31, 2020 and 2019, we have incurred approximately $83 million and $15$5 million, respectively. respectively of Phase 1 GTN XPress Project costs, which were included in the tabular summary above.
GTN XPress is essentially a modernization program designed to replace and upgrade aging compressor infrastructure, increase reliability and integrate cutting-edge technology at sites along its route. This will help GTN reduce greenhouse gas emissions while ensuring the integrity of existing assets. The project will modernize the existing system and also grow capacity and, as such, is a hybrid project which is more like growth capital than maintenance capital.
Our maintenance and growth projects are funded from a combination of cash from operations and debt at both the asset and Partnership levels.

Our consolidated entities have commitments of $4$86 million as of December 31, 20172020 in connection with various maintenance and general plant projects over the next two years.
Please read Part 1, Item 1. “Business” for more details regarding these projects.

Financing Cash Flow Outlook

On January 23, 2018,19, 2021, the board of directors of our General Partner declared the Partnership'sPartnership’s fourth quarter 20172020 cash distribution in the amount of $1.00$0.65 per common unit which was paid on February 13, 201812, 2021 to unitholders of record as of February 2, 2018.January 29, 2021. The total amount of cash distribution paid to common unitholders and General Partner was $76$47 million.

On January 23, 2018,19, 2021, after reviewing GTN's 2020 distributable cashflows, the board of directors of our General Partner declaredTC PipeLines Board did not declare distributions to Class B unitholders in the amount of $15 million which was paid on February 13, 2018.as certain thresholds for a distribution to be made were not exceeded. The Class B distribution represents an amount equal to 30 percent of GTN'sGTN’s distributable cash flow during the year ended December 31, 20172020 less the threshold level of $20 million. For 2018,million and other adjustments that would further reduce the threshold levelamount attributed to Class B unitholders. Beginning in 2021, we expect the impact of the Class B distribution on our cashflows to be significantly lower compared to previous periods.

Debt refinancing:

The Partnership's $350 million aggregate principal amount 4.65 percent Unsecured Senior Notes mature on June 15, 2021. On February 12, 2021, the Partnership exercised its option to redeem the Unsecured Senior Notes on March 15, 2021 at a redemption price equal to 100% of the principal amount of the notes then outstanding, plus unpaid interest accrued to March 15, 2021. Partial funding for the redemption is expected to be provided using cash on hand, and borrowings under the samePartnership’s $500 million Senior Credit Facility.

The Partnership’s $500 million Senior Credit Facility is due in November 2021 and we anticipate such thresholdexpect any outstanding balance will be exceeded inrepaid if the third quarterTC Energy Merger closes, or refinanced or extended prior to maturity if the TC Energy Merger does not close.

It is expected that Tuscarora will refinance its maturing unsecured term loan through an extension of 2018.

the existing facility including the potential to increase the size of the facility to include the financing required for Tuscarora XPress.


It is expected that North Baja will refinance its maturing term loan facility through an extension of the existing facility including the potential to increase the size of the facility to include the financing required for North Baja XPress Project.
Please read Notes 7,8, 10, 13 and 14, Notes to Consolidated Financial Statements included in Part IV, within Item 15. "Exhibits“Exhibits and Financial Statement Schedules".

Schedules.”

The approximately $80 million PXP project,majority of the capital for our growth projects as further discussed in Part 1, Item 1. Business-Recent Business Developments,the "Investing Cash Flow Outlook" section above is expected to be financed through a new credit facility at PNGTS.

debt.

As of February 24, 2021, the available borrowing capacity on our Senior Credit Facility was $500 million.
Non-GAAP Financial Measures: EBITDA, Adjusted EBITDA, and Distributable Cash Flow,

Adjusted Earnings and Adjusted Earnings per Common Unit


EBITDA is an approximate measure of our operating cash flow during the current earnings period and reconciles directly to the most comparable measure of net income. It measures our earnings before deducting interest, taxes, depreciation and amortization,income, which includes net income attributable to non-controlling interests, and it includes earnings from our equity investments.

It measures our net income before deducting interest, depreciation and amortization and taxes.


Adjusted EBITDA is our EBITDA, less (1) earnings from our equity investments, plus (2) distributions from our equity investment, and plus or minus (3) certain non-recurring items (as noted further below) that are significant but not reflective of our underlying operations.

Our Adjusted EBITDA in 2015 excludes the 2018 impact of the $199following non-recurring items:
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Bison’s contract termination proceeds amounting to $97 million non-cashrecognized as revenue during the fourth quarter of 2018;
the $537 million net long-lived asset impairment charge we recognized on our investment in Great Lakes. to Bison’s current carrying value; and
the $59 million impairment charge related to Tuscarora’s goodwill.
We believe the charge isthese items are significant but not reflective of our underlying operations. For the years ended December 31, 20172020 and 2016,2019, we do not have any similarnon-recurring adjustments in our Adjusted EBITDA. Accordingly,
Beginning the first quarter of 2020, the Partnership revised its calculation of Adjusted EBITDA to include distributions from our equity investments, net of equity earnings from our investments as described above, which were previously excluded from such measure. The presentation of Adjusted EBITDA for the yearstwelve months ended December 31, 20172019 and 20162018 was recast to conform with the current presentation. The Partnership believes the revised presentation more closely aligns with similar non-GAAP financial measures presented by our EBITDA ispeers and with the same as Adjusted EBITDA.

Partnership’s definitions of such measures.

Total distributable cash flow and distributable cash flow provide measures of distributable cash generated during the current earnings period and reconcile directly to the net income amount presented.

Total distributable cash flow does not factor in any growth capital spending. It includes our Adjusted EBITDAplus:

EBITDA:
less:
Distributions from our equity investments
AFUDC,
Earnings from our equity investments,

Equity allowance for funds used during construction (Equity AFUDC),

Interest expense,

IncomeCurrent income taxes,

Distributions to non-controlling interests,

and
Distributions to TransCanada as former parent of PNGTS, and

Maintenance capital expenditures.

TC PipeLines, LPAnnual Report2017    55



Distributable cash flow is computed net of distributions declared to the General Partner and any distributions allocable to Class B units. Distributions declared to the General Partner are based on its effective two percent interest plus, if applicable, an amount equal to incentive distributions. Distributions allocable to the Class B units in 2020 equal 30 percent of GTN'sGTN’s distributable cash flow forless $20 million, the yearsresidual of which is further multiplied by 43.75 percent. (Class B Distribution) (2019 and 2018 - less $20 million only).

For the year ended December 31, 20172020, the Class B Distribution was further reduced by 35 percent, which is equivalent to the percentage by which distributions payable to the common units were reduced in 2018 (Class B Reduction). The Class B Reduction was implemented during the first quarter of 2018 following the Partnership’s common unit distribution reduction of 35 percent and December 31, 2016, less $20 million (2015 – less $15 million).

will apply to any calendar year during which distributions payable in respect of common units for such calendar year do not equal or exceed $3.94 per common unit.


Distributable cash flow, EBITDA and Adjusted EBITDA are performance measures presented to assist investors in evaluating our business performance. We believe these measures provide additional meaningful information in evaluating our financial performance and cash generating performance.

capacity.


The non-GAAP financial measures described above are provided as a supplement to GAAP financial results and are not meant to be considered in isolation or as substitutes for financial informationresults prepared in accordance with GAAP. Additionally, these measures as presented may not be comparable to similarly titled measures of other companies.

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 2020     57

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Reconciliations of Net Income (Loss) to EBITDA, Adjusted EBITDA and Distributable Cash Flow

The following table presents a reconciliation of the non-GAAP financial measures of EBITDA, Adjusted EBITDA and Distributable Cash Flow, to the GAAP financial measure of net income.

Year Ended December 31
(unaudited)
(millions of dollars)
 2017 2016(a) 2015(a) 

 
Net income 263 263 58 

 
Add:       
Interest expense(b) 84 73 68 
Depreciation and amortization 97 96 95 
Income taxes 1 1 2 

 
EBITDA 445 433 223 
Impairment of equity investment   199 
ADJUSTED EBITDA 445 433 422 
Add:       
Distributions from equity investments(c)       
 Northern Border 82 91 91 
 Great Lakes 38 34 40 
 Iroquois 41(d)  

 
  161 125 131 
Less:       
Equity earnings:       
 Northern Border (67)(69)(66)
 Great Lakes (31)(28)(31)
 Iroquois (26)  

 
  (124)(97)(97)
Less:       
Equity AFUDC   (1)
Interest expense(b) (84)(73)(68)
Income taxes (1)(1)(2)
Distributions to non-controlling interests(e) (14)(18)(29)
Distributions to TransCanada as PNGTS' former parent(f) (2)(6)(30)
Maintenance capital expenditures(g) (38)(16)(16)

 
  (139)(114)(146)
Total Distributable Cash Flow 343 347 310 
General Partner distributions declared(h) (18)(12)(8)
Distributions allocable to Class B units(i) (15)(22)(12)

 
Distributable Cash Flow 310 313 290 

 
Year Ended December 31
(unaudited)
(millions of dollars)
202020192018
Net income (loss)301 298 (165)
Add (Less):
Interest expense(a)
83 85 94 
Depreciation and amortization89 78 97 
Income tax expense (benefit)6 (1)
EBITDA479 460 27 
Add (less):
Non-recurring items
Impairment of goodwill — 59 
Impairment of long‑lived assets — 537 
Bison contract terminations — (97)
Less:
Equity earnings:
Northern Border(76)(69)(68)
Great Lakes(56)(51)(59)
Iroquois(38)(40)(46)
(170)(160)(173)
Add:
Distributions from equity investments(b)
Northern Border90 93 85 
Great Lakes43 55 66 
Iroquois(c)
46 69 56 
179 217 207 
ADJUSTED EBITDA488 517 560 
Less:
AFUDC(11)(2)(1)
Interest expense(a)
(83)(85)(94)
Current income taxes (d)
(3)(1)(1)
Distributions to non‑controlling interests(e)
(22)(21)(20)
Maintenance capital expenditures(f)
(110)(56)(36)
(229)(165)(152)
Total Distributable Cash Flow259 352 408 
General Partner distributions declared(g)
(4)(4)(4)
Distributions allocable to Class B units(h)
 (8)(13)
Distributable Cash Flow255 340 391 
(a)
Financial information was recast to consolidate PNGTS. Please see "Basis of Presentation" section for more information.

(b)
Interest expense as presented includes net realized loss related to the interest rates swaps and amortization of realized loss on PNGTS'PNGTS’ derivative instruments and does not include amortization of debt issuance and discount costs (Refer to Notes 12 and 19, Notes to Consolidated Financial Statements included in Part IV, within Item 15. "Exhibits“Exhibits and Financial Statement Schedules"Schedules”).

(c)
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(b)These amounts are calculated in accordance with the cash distribution policies of these entities. Distributions from each of our equity investments represent our respective share of these entities' quarterlyentities’ distributable cash during the current reporting period.

TC PipeLines, LPAnnual Report2017    57


(d)
(c)This amount represents our proportional 49.34 percent share of the distribution declared by our equity investee, Iroquois, fromfor the second to fourth quartercurrent reporting period and excludes any distributions received that are considered return of 2017 andinvestment. It also includes our 49.34 percent share of the Iroquois unrestricted cash distribution amounting to approximately $8$10 million for the seven monthsboth years ended December 31, 2017.2019 and December 31, 2018 (2020 - none). In 2020 and 2019, we also received an additional distribution of $4 million and $15 million, respectively related to the increase in the cash Iroquois generated from its higher income in 2017 (post acquisition) to 2020. (Refer to Notes 5 and 7, Notes to Consolidated Financial Statements included in Part IV, within Item 15. "Exhibits“Exhibits and Financial Statement Schedules"Schedules”).

(d)Beginning with the year ended December 31, 2019, we reduced our distributable cashflows by current income tax expense which approximates net cash paid during the current period. The change did not materially impact comparability to prior periods. Additionally, beginning in 2020, the Partnership became subject to a corporate activity tax in Oregon. Current income tax expense includes taxes paid by PNGTS on its New Hampshire state taxes and taxes paid by the Partnership on its Oregon corporate activity tax. For the year ended December 31, 2020, the Partnership recognized $0.6 million for the Oregon corporate activity tax..
(e)
Distributions to non-controlling interests represent the respective share of our consolidated entities'entities’ distributable cash not owned by us during the periods presented.

(f)
Distributions to TransCanada as PNGTS' former parent represent TransCanada's respective share of PNGTS' distributable cash not owned by us during the periods presented.

(g)
The Partnership'sPartnership’s maintenance capital expenditures include expenditures made to maintain, over the long term, our assets'assets’ operating capacity, system integrity and reliability. Accordingly, this amount represents the Partnership'sPartnership’s and its consolidated subsidiaries'Consolidated Subsidiaries’ maintenance capital expenditures and does not include the Partnership'sPartnership’s share of maintenance capital expenditures on our equity investments. Such amounts are reflected in "Distributions“Distributions from equity investments"investments” as those amounts are withheld by those entities from their quarterly distributable cash.

Please read the Capital spending section for more information regarding the Partnership'sPartnership’s total proportionate share of maintenance capital expenditures from our consolidated entities and equity investments.

(h)
(g)Distributions declared to the General Partner for the year ended December 31, 2017 included an2020, 2019 and 2018 did not include any incentive distribution of approximately $12 million (2016 – $7 million; 2015 – $3 million).

(i)
During the twelve months ended December 31, 2017, 30 percent of GTN's total distributions was $35 million; therefore, the distributionsdistributions.
(h)Distributions allocable to the Class B units was $15 million, representing the amount that exceeded the threshold level of $20 million. During the twelve months ended December 31, 2016,is based on 30 percent of GTN's total distributions was $42 million; therefore,GTN’s distributable cashflow during the distributions allocable to the Class B units was $22 million, representing the amount that exceeded the threshold level of $20 million. During the twelve months ended December 31, 2015, 30 percent of GTN's total distributions was $27 million; therefore, the distributions allocable to the Class B units was $12 million, representing the amount that exceeded the threshold level of $15 million. The Class B distribution is determinedcurrent reporting period but declared and payable annually.

On January 23, 2018, the board of directors of our General Partner declared distributions to Class B unitholderspaid in the amount of $15 million which was paid on February 13, 2018. The 2016 Class B distribution amounting to $22 million was paid by the Partnership on February 14, 2017. Please read Notes 7,10,13 and 14, Notes to Consolidated Financial Statements forsubsequent reporting period. During the year ended December 31, included2020, no distributions were declared as certain thresholds in Part IV within Item 15. "Exhibits and Financial Statement Schedules".

the agreement were not met. Beginning in 2021, we expect the impact of Class B distribution on our distributable cashflow to be significantly lower compared to previous periods.

Year Ended December 31, 20172020 Compared with the Year Ended December 31, 2016

2019


Our EBITDA and Adjusted EBITDA was $12higher for the year ended December 31, 2020 compared to the same period in 2019. The $19 million higherincrease was primarily due to the addition oflower operating costs and higher equity earnings, from Iroquois effective June 1, 2017partially offset by lower revenues and an increase in operational costs on ourrevenue from consolidated subsidiaries as discussed in more detail under the "Results“Results of Operations"Operations” section.


Our Adjusted EBITDA was lower for the year ended December 31, 2020 compared to the same period in 2019. The $29 million decrease was primarily due to:
lower operating costs partially offset by lower revenue from consolidated subsidiaries as discussed in more detail under the “Results of Operations” section;
no distributions from Great Lakes during the third quarter as it used the cash generated during the period to fund a one-time commercial IT system purchase from a TC Energy affiliate on August 1, 2020. This will reduce future operating costs and will increase Great Lakes’ rate base and we anticipate will generate a return on and of capital in future rates; and
lower distributions from Iroquois as Iroquois satisfied its final surplus cash distribution obligation of $2.6 million per quarter in the fourth quarter of 2019; and in the third quarter of 2019, we received an additional one-time $15 million distribution representing our proportionate share of the excess cash accumulated by Iroquois between 2018 and 2019 from its earnings.

Our distributable cash flow fordecreased by $85 million during the twelve monthsyear ended December 31, 2017 was comparable2020 compared to the same period in 20162019 due to the net effect of:


lower Adjusted EBITDA;
one-time cash impact related to the additionfunding of a commercial IT system purchase by GTN, Tuscarora and North Baja from a TC Energy affiliate on August 1, 2020. These expenditures will reduce future operating costs and increase our 49.34 percent sharepipelines’ respective rate bases and we anticipate will generate a return on and of distributions declared by Iroquois from the second to fourth quarter of 2017;

lower revenues from our subsidiaries and increasescapital in their operational costs as previously discussed above in "Results of Operations";

future rates; and
higher financing costsmaintenance capital expenditures at GTN as a result of increased spending on major equipment overhauls at several compressor stations and certain system upgrades.
Year Ended December 31, 2019 Compared with the 2017 Acquisition;

Year Ended December 31, 2018

Our EBITDA was $433 million higher in 2019 compared to 2018 due to the 2018 goodwill impairment of $59 million for Tuscarora and the long-lived asset impairment for Bison of $537 million, partially offset by the additional $97 million in revenue recognized for the Bison contract terminations.

Our Adjusted EBITDA was lower by $43 million due to the net effect of:
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significantly lower revenues from Bison from being 100 percent fully contracted in 2018 to only approximately 40 percent in 2019 and an overall increase in our operating expenses from our consolidated subsidiaries as discussed in more detail in the Results of Operations Section;
higher distributions from our equity investment in Northern Border primarily due to lower capital spending related to compressor station maintenance costs;
lower distributions from Great Lakes resulting from decreased earnings and increased maintenance capital spending;
additional distribution received from Iroquois due to the surplus cash accumulated from previous years' higher net income;

Our distributable cash flow decreased by $51 million for the year ended December 31, 2019 compared to the same period in 2018 due to the net effect of:
lower Adjusted EBITDA as a result of lower revenues and higher operating expenses from consolidated subsidiaries offset by higher distributions from our equity investments as discussed above
higher maintenance capital expenditures related to major compression equipment overhauls and pipe integrity costs on GTN's pipeline system;

lower distributable cash flow from Northern Border primarily due to its higher operating costs and higher maintenance capital expenditures;

higher distributions declared in respect of our IDRs during 2017; and

lower distributions allocable to the Class B units during 2017.

58    TC PipeLines, LPAnnual Report2017


Year Ended December 31, 2016 Compared with the Year Ended December 31, 2015

EBITDA increased by $210 million to $433 million in 2016 compared to $223 million in 2015. The increase was primarily the result of the recognition of a $199 million non-cash impairment charge in 2015 to our investment in Great Lakes which lowered EBITDA in 2015 accordingly (See Critical Accounting Estimates – Impairment of Equity Investments, Goodwill and Long-Lived Assets – Equity Investments section for more information.)

Adjusted EBITDA increased by $11 million compared to the same period in 2015 mainly due to higher transmission revenues as discussed in more detail in the Results of Operations section.

Distributable cash flow increased by $23 million in the twelve months ended December 31, 2016 compared to the same period in 2015 primarily due to the net effect of:

the cash impact of higher Adjusted EBITDA;

lower distributable cash flow from our equity investmentsGTN as a result of higher maintenance capital in 2016 as discussed in more detail on the "Capital Spending" section;

transportation volumes of natural gas;
lower distributions paid to non-controlling interestsinterest expense due to the Partnership owning 100 percentfull repayment of GTN effective April 1, 2015;

the $170 million Term Loan during the fourth quarter of 2018 and the partial repayment of borrowings under our Senior Credit Facility in the first quarter of 2019; and
lower Class B allocation due to lower distributable cash flow allocable to TransCanada as the former parent of PNGTS due to the Partnership's acquisition of 49.9 percent interest in PNGTS from TransCanada effective January 1, 2016;

higher interest expense related to higher borrowings as a result of the recent acquisitions offset by;

higher General Partner distributions due to higher IDRs in the current period; and

higher distributions allocable to the Class B units during the current period.

TC PipeLines, LPAnnual Report2017    59


generated by GTN.

The Partnership’s Contractual Obligations

The Partnership's Contractual Obligations

The Partnership'sPartnership’s contractual obligations as of December 31, 20172020 included the following:

    
Payments Due by Period

 
(unaudited)
(millions of dollars)
 Total Less than
1 Year
 1-3
Years
 4-5
Years
 More than
5 Years
 Weighted
Average
Interest
Rate for the
Year
Ended
December 31,
2017
 

 
TC PipeLines, LP             
Senior Credit Facility due 2021 185   185  2.41% 
2013 Term Loan Facility due 2022 500   500  2.33% 
2015 Term Loan Facility due 2020 170  170   2.22% 
4.65% Senior Notes due 2021 350   350  4.65%(a)
4.375% Senior Notes due 2025 350    350 4.375%(a)
3.90% Senior Notes due 2027 500    500 3.90%(a)
GTN             
5.29% Unsecured Senior Notes due 2020 100  100   5.29%(a)
5.69% Unsecured Senior Notes due 2035 150    150 5.69%(a)
Unsecured Term Loan Facility due 2019 55 20 35   2.02% 
PNGTS             
5.90% Senior Secured Notes due 2018 30 30    5.90%(a)
Tuscarora             
Unsecured Term Loan due 2020 25 1 24   2.27% 

 
  2,415 51 329 1,035 1,000   

 
Payments Due by Period
(unaudited)
(millions of dollars)
Total
Less than
1 Year
1‑3 Years4‑5 Years
More than
5 Years
Weighted Average Interest Rate for the Year Ended December 31,
2020
TC PipeLines, LP
Senior Credit Facility due 2021— — — — — — 
2013 Term Loan Facility due 2022450 — 450 —��— 1.87 %
4.65% Senior Notes due 2021350 350 — — — 4.65 %(a)
4.375% Senior Notes due 2025350 — — 350 — 4.375 %(a)
3.90% Senior Notes due 2027500 — — — 500 3.90 %(a)
GTN
5.69% Unsecured Senior Notes due 2035150 — — — 150 5.69 %(a)
3.12% Unsecured Senior Notes due 2030175 — — — 175 3.12 %(a)
PNGTS
Revolving Credit Facility due 202325 — 25 — — 1.88 %
2.84% Unsecured Senior Notes due 2030125 — — — 125 2.84 %(a)
Tuscarora— 
Unsecured Term Loan due 202123 23 — — — 2.13 %
North Baja
Unsecured Term Loan due 202150 50 — — — 1.70 %
Partnership (TC PipeLines, LP and its subsidiaries)
Interest on debt obligations(b)
428 71 112 93 152 
Operating leases— — — 
2,627 495 587 443 1,102 
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(a)
Fixed Raterate debt

(b)
InterestFuture interest payments on floating-rateour fixed rate debt are based on scheduled maturities. Future interest payments on floating rate debt are estimated using debt levels and interest rates effective as of December 31, 2017.

TC PipeLines, LP

On November 10, 2016, the Partnership's Senior Credit Facility was amended to extend the maturity period through November 10, 2021. The Facility consists of a $500 million senior revolving credit facility with a banking syndicate, under which $185 million was outstanding at December 31, 2017 (December 31, 2016 – $160 million), leaving $315 million available for future borrowing.

At the Partnership's option, the2020 and are therefore subject to change beyond 2020. Future interest payments on floating rate debt do not include potential obligation related to our interest rate onswaps.

Additional information regarding the outstanding borrowings under the Senior Credit Facility may be lenders' base rate or the London Interbank Offered Rate (LIBOR) plus, in either case, an applicable margin that is based on the Partnership's long-term unsecured credit ratings. The Senior Credit Facility permits the Partnership to specify the

60    TC PipeLines, LPAnnual Report2017



portion of the borrowings to be covered by specificPartnership’s debt and interest rate options and, for LIBOR-based borrowings, to specify the interest rate period. The Partnership is required to pay a commitment fee based on its credit rating and on the unused principal amount of the commitments under the Senior Credit Facility. The Senior Credit Facility has a feature whereby at any time, so long as no event of default has occurred and is continuing, the Partnership may request an increase in the Senior Credit Facility of up to $500 million, but no lender has an obligation to increase their respective share of the facility.

The LIBOR-based interest rate on the Senior Credit Facility was 2.62 percent at December 31, 2017 (December 31, 2016 – 1.92 percent).

On July 1, 2013, the Partnership entered into a term loan agreement with a syndicate of lenders for a $500 million term loan credit facility (2013 Term Loan Facility). On July 2, 2013, the Partnership borrowed $500 million under the 2013 Term Loan Facility, to pay a portion of the purchase price of the 2013 Acquisition, maturing originally on July 1, 2018. On September 29, 2017, the Partnership's 2013 Term Loan Facility was amended to extend the maturity period through October 2, 2022. The 2013 Term Loan Facility bears interest based, at the Partnership's election, on the LIBOR or the base rate plus, in either case, an applicable margin. The base rate equals the highest of (i) SunTrust Bank's prime rate, (ii) 0.50 percent above the federal funds rate and (iii) 1.00 percent above one-month LIBOR. The applicable margin for the term loan is based on the Partnership's senior debt rating and ranges between 1.125 percent and 2.00 percent for LIBOR borrowings and 0.125 percent and 1.00 percent for base rate borrowings.

As of December 31, 2017, the variable interest rate exposure related to 2013 Term Loan Facility was hedged by fixed interest rate swap arrangements and our effective interest rate was 2.31 percent (2016-2.31 percent). Prior to hedging activities, the LIBOR-based interest rate was 2.62 percent at December 31, 2017 (December 31, 2016 – 1.87 percent).

On September 30, 2015, the Partnership entered into an agreement for a $170 million term loan credit facility (2015 Term Loan Facility). The Partnership borrowed $170 million under the 2015 Term Loan Facility to refinance its Short-Term Loan Facility which matured on September 30, 2015. On September 29, 2017, the Partnership's 2015 Term Loan Facility that was due on October 1, 2018 was amended to extend the maturity period through October 1, 2020. The LIBOR-based interest rate on the 2015 Term Loan Facility was 2.51 percent at December 31, 2017 (December 31, 2016 – 1.77 percent).

The 2013 Term Loan Facility and the 2015 Term Loan Facility (Term Loan Facilities) and the Senior Credit Facility require the Partnership to maintain a certain leverage ratio (debt to adjusted cash flow [net income plus cash distributions received, extraordinary losses, interest expense, expense for taxes paid or accrued, and depreciation and amortization expense less equity earnings and extraordinary gains]) no greater than 5.00 to 1.00 for each fiscal quarter, except for the fiscal quarter and the two following fiscal quarters in which one or more acquisitions has been executed, in which case the leverage ratio is to be no greater than 5.50 to 1.00. The leverage ratio was 4.70 to 1.00 as of December 31, 2017.

The Senior Credit Facility and the Term Loan Facilities contain additional covenants that include restrictions on entering into mergers, consolidations and sales of assets, granting liens, material amendments to the Partnership Agreement, incurrence of additional debt by the Partnership's subsidiaries and distributions to unitholders. Upon any breach of these covenants, amounts outstanding under the Senior Credit Facility and the Term Loan Facilities may become immediately due and payable.

On March 13, 2015, the Partnership closed a $350 million public offering of senior unsecured notes bearing an interest rate of 4.375 percent maturing March 13, 2025. The net proceeds of $346 million were used to fund a portion of the 2015 GTN Acquisition (refer to Note 7) and to reduce the amount outstanding under our Senior Credit Facility. The indenture for the notes contains customary investment grade covenants.

On May 25, 2017, the Partnership closed a $500 million public offering of senior unsecured notes bearing an interest rate of 3.90 percent maturing May 25, 2027. The net proceeds of $497 million were used to fund a portion of the 2017 Acquisition (Refer to Note 7). The indenture for the notes contains customary investment grade covenants.

TC PipeLines, LPAnnual Report2017    61


PNGTS

PNGTS' Senior Secured Notes are secured by the PNGTS long-term firm shipper contracts and its partners' pledge of their equity and a guarantee of debt service for six months. PNGTS is restricted under the terms of its note purchase agreement from making cash distributions unless certain conditions are met. Before a distributionswaps can be made, the debt service reserve account must be fully fundedfound under Note 8 - Debt and PNGTS' debt service coverage ratio for the precedingCredit Facilities and succeeding twelve months must be 1.30 or greater. At December 31, 2017, the debt service coverage ratio was 1.72 for the twelve preceding monthsNote 19 - Fair Value measurements, respectively within Part IV, Item 15. “Exhibits and 1.53 for the twelve succeeding months. Therefore, PNGTS was not restricted to make any cash distributions.

GTN

On June 1, 2015, GTN entered into a $75 million unsecured variable rate term loan facility (Unsecured Term Loan Facility),Financial Statement Schedules,” which requires yearly principal payments until its maturity on June 1, 2019. The variable interestinformation is based on LIBOR plus an applicable margin. The LIBOR-based interest rate on the Unsecured Term Loan Facility was 2.31 percent at December 31, 2017 (December 31, 2016 – 1.57 percent). GTN's Unsecured Senior Notes, along with this new Unsecured Term Loan Facility contain a covenant that limits total debt to no greater than 70 percent of GTN's total capitalization. GTN's total debt to total capitalization ratio at December 31, 2017 is 44.6 percent.

Tuscarora

On August 21, 2017, Tuscarora refinanced all of its outstanding debtincorporated herein by amending its existing Unsecured Term Loan Facility and issuing a new $25 million variable rate term loan that will require yearly principal payments and will mature on August 21, 2020. Tuscarora's Unsecured Term Loan contains a covenant that requires Tuscarora to maintain a debt service coverage ratio (cash available from operations divided by a sum of interest expense and principal payments) of greater than or equal to 3.00 to 1.00. As of December 31, 2017, the ratio was 11.09 to 1.00.

The LIBOR-based interest rate on the Tuscarora's Unsecured Term Loan Facility was 2.49 percent at December 31, 2017 (December 31, 2016 – 1.90 percent).

Partnership (TC PipeLines, LP and its subsidiaries)

At December 31, 2017, the Partnership was in compliance with its financial covenants, in addition to the other covenants which include restrictions on entering into mergers, consolidations and sales of assets, granting liens, material amendments to the Partnership Agreement, incurring additional debt and distributions to unitholders.

The fair value of the Partnership's long-term debt is estimated by discounting the future cash flows of each instrument at estimated current borrowing rates. The estimated fair value of the Partnership's long-term debt at December 31, 2017 was $2,475 million. As of February 26, 2018, the Partnership had $170 million outstanding under the Senior Credit Facility.

62    TC PipeLines, LPAnnual Report2017


reference.

Summary of Northern Border'sBorder’s Contractual Obligations

Northern Border'sBorder’s contractual obligations as of December 31, 20172020 included the following:

    
Payments Due by Period(a)

(unaudited)
(millions of dollars)
 Total Less than
1 Year
 1-3
Years
 4-5
Years
 More than
5 Years
  

7.50% Senior Notes due 2021 250   250   
$200 million Credit Agreement due 2020 15  15    
Interest payments on debt 74 20 39 15   
Other commitments(b) 53 3 5 5 40  

  392 23 59 270 40  

Payments Due by Period(a)
(unaudited)
(millions of dollars)
Total
Less than
1 Year
1‑3
Years
4‑5
Years
More than
5 Years
$200 million Credit Agreement due 2024130 — — 130 — 
7.50% Senior Notes due 2021 (b)
250 250 — — — 
Interest payments on debt (c)
20 15 — 
Other commitments(d)
47 32 
447 268 10 137 32 
(a)
Represents 100 percent of Northern Border'sBorder’s contractual obligations.

(b)
Expected to have the financing arranged to repay this debt at maturity.
(c)Future interest payments on our fixed rate debt are based on scheduled maturities. Future interest payments on floating rate debt are estimated using debt levels and interest rates at December 31, 2020 and are therefore subject to change.
(d)Future minimum payments for office space and rights-of-way commitments.

Northern Border has commitments of $7$15 million as of December 31, 20172020 in connection with various pipeline, metering and overhaul projects.

At December 31, 2017, the aggregate estimated fair value of Northern Border's long-term debt was approximately $294 million (2016 – $464 million). In 2017, interest expense related to the senior notes was $19 million (2016 – $23 million; 2015 – $25 million).

Senior Notes

Northern Border'sBorder’s outstanding debt securities are senior unsecured notes. The indentures for the notes do not limit the amount of unsecured debt Northern Border may incur but do restrict secured indebtedness. At December 31, 2017,2020, Northern Border was in compliance with all of its financial covenants.

Credit Agreement

Northern Border'sBorder’s credit agreement consists of a $200 million revolving credit facility. On October 1, 2019, the credit agreement was extended to mature on October 1, 2024. At December 31, 2017, $152020, $130 million was outstanding leaving $185 million available for future borrowings.on this facility. At Northern Border'sBorder’s option, the interest rate on the outstanding borrowings may be the lenders' base rate or LIBOR plus, in either case, an applicable margin that is based on Northern Border'sBorder’s long-term unsecured credit ratings. The interest rate on Northern Border'sBorder’s credit agreement at December 31, 20172020 was 2.121.28 percent (2016(20191.902.82 percent). At December 31, 2017,2020, Northern Border was in compliance with all of its financial covenants.

Please read Part II Item 7A- "Quantitative and Qualitative Disclosures About Market Risk." for information about LIBOR phase-out.

Summary of Great Lakes'Lakes’ Contractual Obligations

Great Lakes'Lakes’ contractual obligations as of December 31, 20172020 included the following:

    
Payments Due by Period(a)

(unaudited)
(millions of dollars)
 Total Less than
1 Year
 1-3
Years
 4-5
Years
 More than
5 Years
  

6.73% series Senior Notes due 2016 to 2018 9 9     
9.09% series Senior Notes due 2016 to 2021 40 10 20 10   
6.95% series Senior Notes due 2019 to 2028 110  22 22 66  
8.08% series Senior Notes due 2021 to 2030 100   20 80  
Interest payments on debt 120 20 34 26 40  

  379 39 76 78 186  

Payments Due by Period(a)
(unaudited)
(millions of dollars)
Total
Less than
1 Year
1‑3
Years
4‑5
Years
More than
5 Years
9.09% series Senior Notes due 202110 10 — — — 
6.95% series Senior Notes due 2021 to 202888 11 22 22 33 
8.08% series Senior Notes due 2021 to 2030100 10 20 20 50 
Interest payments on debt (b)
66 14 22 16 14 
Right-of-way commitments— — — 
265 45 64 58 98 
(a)
Represents 100 percent of Great Lakes'Lakes’ contractual obligations.

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(b)Future interest payments on our fixed rate debt are based on scheduled maturities
Great Lakes has commitments of $3$6 million as of December 31, 20172020 in connection with compressor overhaul projects.

Long-Term Financing

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All of Great Lakes'Lakes’ outstanding debt securities are senior unsecured notes with similar terms except for interest rates, maturity dates and prepayment premiums.

Great Lakes is required to comply with certain financial, operational and legal covenants. Under the most restrictive covenants in the senior note agreements, approximately $139$107 million of Great Lakes' partners'Lakes’ partners’ capital was restricted as to distributions as of December 31, 2017 (2016 – $1502020 (2019 - $118 million). Great Lakes was in compliance with all of its financial covenants at December 31, 2017.

The aggregate estimated fair value of Great Lakes' long-term debt was $335 million at December 31, 2017 (2016 – $354 million). The aggregate annual required repayment of senior notes is $19 million for 2018, $21 million for each year 2019 and 2020, $31 million for 2021 and $21 million for 2022. Aggregate required repayments of senior notes thereafter total $146 million. In 2017, interest expense related to Great Lakes' senior notes was $21 million (2016 – $22 million; 2015 – $24 million).

Other

Great Lakes has a cash management agreement with TransCanada whereby Great Lakes' funds are pooled with other TransCanada affiliates. The agreement also gives Great Lakes the ability to obtain short-term borrowings to provide liquidity for Great Lakes' operating needs. At December 31, 2017 and 2016, Great Lakes has an outstanding receivable from this arrangement amounting to $64 million and $27 million, respectively.

2020.

Summary of Iroquois'Iroquois’ Contractual Obligations

Iroquois'

Iroquois’ contractual obligations as of December 31, 20172020 included the following:

    
Payments Due by Period(a)

(unaudited)
(millions of dollars)
 Total Less than
1 Year
 1-3
Years
 4-5
Years
 More than
5 Years
  

6.63% series Senior Notes due 2019 140  140    
4.84% series Senior Notes due 2020 150  150    
6.10% series Senior Notes due 2027 39 4 9 7 19  
Interest payments on debt 43 19 18 3 3  
Transportation by others(b) 15 3 6 6   
Operating leases 7 1 3 1 2  
Pension contributions(c) 1 1     

  395 28 326 17 24  

Payments Due by Period(a)
(unaudited)
(millions of dollars)
Total
Less than
1 Year
1‑3
Years
4‑5
Years
More than
5 Years
4.12% series Senior Notes due 2034140 — — — 140 
4.07% series Senior Notes due 2030150 — — — 150 
6.10% series Senior Notes due 202726 
Interest payments on debt (b)
141 13 26 25 77 
Transportation by others(c)
— — 
Operating leases10 
Pension contributions(d)
— — — 
474 23 38 35 378 
(a)
Represents 100 percent of Iroquois'Iroquois’ contractual obligations.

(b)
Future interest payments on our debt are based on scheduled maturities.
(c)Rates are based on known 20182020 levels. Beyond 2018,2021, demand rates are subject to change.

(c)
(d)Pension contributions cannot be reasonably estimated by Iroquois beyond 2018.

2021.

Iroquois has no commitments of $2 million as of December 31, 20172020 relative to procurement of materials on its expansion project.

During the third quarter of 2017, Iroquois' partners adopted a distribution resolution to address the surplus cash on Iroquois' balance sheet. Under the terms of the resolution, Iroquois is expected to distribute approximately $57.6 million of unrestricted cash to its partners over 11 quarters, which began with Iroquois' second quarter 2017 distribution on August 1, 2017. As of February 26, 2018, Iroquois has distributed approximately $15.7 million of the expected $57.6 million, of which our proportionate share was approximately $7.8 million. Please read Note 7, Notes to Consolidated Financial Statements included in Part IV within Item 15. "Exhibits and Financial Statement Schedules"

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capital expenditures.

Iroquois is restricted under the terms of its note purchase agreement from making cash distributions to its partners unless certain conditions are met. Before a distribution can be made, the debt/capitalization ratio must be below 75%75 percent and the debt service coverage ratio must be at least 1.25 times for the four preceding quarters. At December 31, 2017,2020, the debt/capitalization ratio was 47.4%57.7 percent and the debt service coverage ratio was 5.527.08 times, therefore, Iroquois was not restricted from making any cash distributions.

Cash Distribution Policy of the Partnership

The following table illustrates the percentage allocations of available cash from operating surplus between the common unitholders and our General Partner after providing for Class B distributions based on the specified target distribution levels. The percentage interests set forth below for our General Partner include its IDRs and two percent general partner interest and IDRs, and assume our General Partner has contributed any additional capital necessary to maintain its two percent general partner interest. The distributionpercentage interest distributions to the General Partner illustrated below other than in its capacity as a holder of 5,797,106 common units that are in excess of its effective two percent general partner interest representsrepresent the IDRs.

    
Marginal Percentage
Interest in Distribution

  
  Total Quarterly Distribution
Per Unit Target Amount
 Common
Unitholders
 General
Partner
  

Minimum Quarterly Distribution $0.45 98% 2%  
First Target Distribution above $0.45 up to $0.81 98% 2%  
Second Target Distribution above $0.81 up to $0.88 85% 15%  
Thereafter above $0.88 75% 25%  

The following table provides information about

Marginal Percentage
Interest in Distribution
Total Quarterly Distribution
Per Unit Target Amount
Common
Unitholders
General
Partner
Minimum Quarterly Distribution$0.4598 %%
First Target Distributionabove $0.45 up to $0.8198 %%
Second Target Distributionabove $0.81 up to $0.8885 %15 %
Thereafterabove $0.8875 %25 %

Our quarterly declared cash distributions in 2020 remained the same as in 2019, which was $0.65 per common unit or $2.60 per common unit in total for the year. Incentive distributions (IDRs) are paid to our General Partner if quarterly cash distributions (in millions, except per unit distributions amounts)on the common units exceed levels specified in the Fourth Amended and Restated Agreement of Limited Partnership of the Partnership (as amended, the Partnership Agreement).

      Limited Partners

 General Partner

    

Declaration
Date
 
Payment
Date
 
Per Unit
Distribution
 
Common
Units
 
Class B
Units(c)
 
2%
 
IDRs(a)
 
Total Cash
Distribution
  

1/22/2015 2/13/2015 $0.84 $54 $– $1 $– $55  
4/23/2015 5/15/2015 $0.84 $54 $– $1 $– $55  
7/23/2015 8/14/2015 $0.89 $56 $– $2 $1 $59  
10/22/2015 11/13/2015 $0.89 $57 $– $1 $1 $59  
1/21/2016 2/12/2016 $0.89 $57 $12(d)$1 $1 $71  
4/21/2016 5/13/2016 $0.89 $58 $– $1 $1 $60  
7/21/2016 8/12/2016 $0.94 $62 $– $1 $2 $65  
10/20/2016 11/14/2016 $0.94 $63 $– $1 $2 $66  
1/23/2017 2/14/2017 $0.94 $64 $22(e)$2 $2 $90  
4/25/2017 5/15/2017 $0.94 $65 $– $1 $2 $68  
7/20/2017 8/11/2017 $1.00 $69 $– $2 $3 $74  
10/24/2017 11/14/2017 $1.00 $70 $– $1 $3 $74  
1/23/2018(b)2/13/2018(b)$1.00 $71 $15(f)$2 $3 $91  

(a)
The distributions paiddeclared during 2020 did not reach the year ended December 31, 2017 included incentive distributions tospecified levels for any period and, therefore, the General Partner did not receive any distributions in respect of $10 million (2016 – $6 million, 2015 – $2 million).

(b)
On February 13, 2018, weits IDRs in 2020. To date, there has been no annual Class B distribution for 2021. In 2020, the Class B distribution paid a cash distribution of $1.00 per unit on our outstanding common units to unitholders of record at the close of business on February 2, 2017. Please readwas $8 million. For more information, please see Note 14 Notes to Consolidated Financial Statements included in Part IV within Item 15. "Exhibits and Financial Statement Schedules"

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(c)
The Class B units issued by us on April 1, 2015 represent limited partner interests in us and entitle TransCanada to an annual distribution which is an amount based on 30 percent of GTN's annual distributions after exceeding certain annual thresholds. Please read Notes 7, 10 and 13, Notes to Consolidated Financial Statements included in Part IV within Item 15. "Exhibits and Financial Statement Schedules".

(d)
On February 12, 2016, we paid TransCanada $12 million representing 30 percent of GTN's total distributable cash flows for the nine months ended December 31, 2015 less $15 million. Please read Notes 7, 10 and 13- Cash Distributions within Part IV, Item 15. "Exhibits“Exhibits and Financial Statement Schedules" for more detailed disclosures on the Class B units.

(e)
On February 14, 2017, we paid TransCanada $22 million representing 30 percent of GTN's total distributable cash flows for the year ended December 31, 2016 less $20 million Please read Notes 7, 10 and 13, Notes to Consolidated Financial Statements included in Part IV within Item 15. "Exhibits and Financial Statement Schedules".

(f)
On February 13, 2018, we paid TransCanada $15 million representing 30 percent of GTN's total distributable cash flows for the year ended December 31, 2017 less $20 million Please read Notes 10 and 25, Notes to Consolidated Financial Statements included in Part IV within Item 15. "Exhibits and Financial Statement Schedules".

Schedules.”

Distribution Policies of Our Pipeline Systems

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Distributions of available cash are made to partners on a pro rata basis according to each partner'spartner’s ownership percentage, approximately one month following the end of a quarter. Our pipeline systems'systems’ respective management committees determine the amounts and timing of cash distributions, where the amounts of such distributions are based on distributable cash flow as determined by a prescribed formula. Any changes to, or suspension of our pipeline systems'systems’ cash distribution policies requires the unanimous approval of their respective management committees.

GTN, Bison, PNGTS and North Baja'sBaja’s distribution policies require the pipelines to distribute 100 percent of distributable cash flow based on earnings before depreciation and amortization less allowance for funds used during construction (AFUDC)AFUDC and maintenance capital expenditures. This defined formula is subject to management committee approval and can be modified to ensure minimum cash balances, equity balances and ratios are maintained.

Tuscarora's

Tuscarora’s distribution policy requires the distribution of 100 percent of distributable cash flow based on earnings before depreciation and amortization less debt repayment, AFUDC and maintenance capital expenditures. This defined formula is subject to management committee approval and can be modified to ensure minimum cash balances, equity balances and ratios are maintained.

PNGTS

Iroquois and IroquoisPNGTS distribute their available cash less any required reserves that are necessary to comply with debt covenants and/or appropriately conduct their respective businesses, as determined and approved by their management committees. While PNGTS'PNGTS’ and Iroquois'Iroquois’ debt repayments are not funded with cashcapital calls to their owners, PNGTS and Iroquois have historically funded scheduled debt repayments by adjusting cash available cash for distribution, which effectively reduces the amount of cash available for distributions.

Northern Border'sBorder’s distribution policy requires Northern Border to distribute on a monthly basis, 100 percent of the distributable cash flow based on earnings before interest, taxes, depreciation and amortization less interest expense and maintenance capital expenditures. Northern Border adopted certain changes related to equity contributions that defined minimum equity to total capitalization ratios to be used by the Northern Border management committee to determine the amount of required equity contributions, timing of the required contributions and for any shortfall due to the inability to refinance maturing debt to be funded by equity contributions.

Great Lakes'Lakes’ distribution policy requires the distribution of 100 percent of distributable cash flow based on earnings before income taxes, depreciation, AFUDC less capital expenditures and debt repayments not funded with cash calls to its partners. This defined formula is subject to management committee approval and can be modified to ensure minimum cash balances, equity balances and ratios are maintained.

CRITICAL ACCOUNTING ESTIMATES

The preparation of financial statements in accordance with GAAP requires us to make estimates and assumptions with respect to values or conditions which cannot be known with certainty, that affect the reported amount of assets and

66    TC PipeLines, LPAnnual Report2017



liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements. Such estimates and assumptions also affect the reported amounts of revenue and expenses during the reporting period. Although we believe these estimates and assumptions are reasonable, actual results could differ.

We believe our critical accounting estimates discussed in the following paragraphs require us to make the most significant assumptions when preparing our financial statements and changes in these assumptions could have a material impact on the financial statements. These critical accounting estimates should be read in conjunction with our accounting policies summarized on Notes 2 and 3, Notes to Consolidated Financial Statements included in Part IV within Item 15. "Exhibits“Exhibits and Financial Statement Schedules".

Schedules."

Regulation

Our pipeline systems'systems’ accounting policies conform toAccounting Standards Codification (ASC) 980 – Regulated Operations. As a result, our pipeline systems record assets and liabilities that result from the regulated ratemakingrate-making process that may not be recorded under GAAP for non-regulated entities. Regulatory assets generally represent incurred costs that have been deferred because such costs are probable of future recovery in customer rates. Regulatory liabilities generally represent obligations to make refunds to customers or for instances where the regulator provides current rates that are intended to recover costs that are expected to be incurred in the future. Our pipeline systems consider several factors to evaluate their continued application of the provisions of ASC 980 such as potential deregulation of their pipelines; anticipated changes from cost-based ratemakingrate-making to another form of regulation; increasing competition that limits their ability to recover costs; and regulatory actions that limit rate relief to a level insufficient to recover costs.

Certain assets that result from the ratemakingrate-making process are reflected on the balance sheets of our pipeline systems. If it is determined that future recovery of these assets is no longer probable as a result of discontinuing application of ASC 980 or other regulatory actions, our pipeline systems would be required to write off the regulatory assets at that time.

Due to the impairment recognized on Bison during the fourth quarter of 2018 (discussed in more detail below under “Long-Lived Assets”), ASC 980 on Bison was discontinued as the future recovery of costs is no longer probable. The impact of ASC 980 discontinuance on Bison was immaterial to the consolidated results of the Partnership.

At December 31, 2020, the Partnership had no regulatory assets or regulatory liabilities reported as part of other current assets or accounts payable and accrued liabilities on the balance sheet, respectively.
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As of December 31, 2017,2020, our equity investees have regulatory assets amounting to $17$14 million (2016 – $15(2019 - $13 million).

As of December 31, 2017,2020, our equity investees have regulatory liabilities amounting to $28$45 million (2016 – $27(2019 - $39 million).

At December 31, 2017, the Partnership had nil million regulatory assets reported as part of other current assets on the balance sheet representing volumetric fuel tracker assets that are settled with in-kind exchanges with customers continually (2016 – $1 million).

As of December 31, 2017,2020, the Partnership had regulatory liabilities of $26$38 million mostlylargely related to estimated costs associated with future removal of transmission and gathering facilities or allowed by FERC to be collected by FERC in depreciation rates (also known as "negative salvage"“negative salvage”) (2016(2019 - $29 million).
Impairment of Goodwill, Long-Lived Assets and Equity Investments
Goodwill
We test goodwill for impairment annually based on ASC 350$25 million).

The 2017 Tax Act

On December 22, 2017,Intangibles – Goodwill and Other, or more frequently if events or changes in circumstances lead us to believe it might be impaired. We can initially assess qualitative factors to determine whether events or changes in circumstances indicate that the Presidentgoodwill might be impaired and, if we conclude that there is not a greater than 50 percent likelihood that the fair value of the United States signed into lawreporting unit is greater than its carrying value, will then perform the 2017 Tax Act.quantitative goodwill impairment test. We can also elect to proceed directly to the quantitative goodwill impairment test for any of its reporting units. If the quantitative goodwill impairment test is performed, the Partnership compares the fair value of the reporting unit to its carrying value, including its goodwill. If the carrying value of a reporting unit including its goodwill exceeds its fair value, goodwill impairment is measured at the amount by which the reporting unit’s carrying value exceeds its fair value.

We base these valuations on our projection of future cash flows which involves making estimates and assumptions about:
discount rates and multiples;
commodity and capacity prices;
market supply and demand assumptions;
growth opportunities;
output levels;
competition from other companies;
regulatory changes; and
regulatory rate action or settlement.
If our assumptions are not appropriate, or future events indicate that our goodwill is impaired, our net income would be impacted by the amount by which the carrying value exceeds the fair value of reporting unit, to the extent of the balance of goodwill.
Under U.S. GAAP, we evaluate our goodwill related to Tuscarora and North Baja for impairment at least annually and if any indicators of impairment are evident.
In 2018, our analysis resulted in the estimated fair value of Tuscarora not exceeding its carrying value, including goodwill that primarily resulted from the 2019 Tuscarora Settlement as part of the 2018 FERC Actions. As a result, we recorded a goodwill impairment charge amounting to $59 million against Tuscarora’s goodwill balance of $82 million.

In 2019, based on our analysis of Tuscarora and North Baja’s current market conditions, we believed there was a greater than 50 percent likelihood that Tuscarora and North Baja’s estimated fair value exceeded their carrying value. As a result, at December 31, 2019, we did not identify an impairment on the $71 million of goodwill related to the Tuscarora ($23 million) and North Baja ($48 million) reporting units.

During our interim process we evaluated changes within our business and the external environment to assess whether a triggering event had occurred. This legislation provides for majoranalysis included the interim assessment of the impact of COVID-19 to our reporting units. Through this interim analysis, no triggering events were identified. Additionally, our annual impairment analysis on goodwill, resulted in a conclusion that there was a greater than 50 percent likelihood that both Tuscarora’s and North Baja’s estimated fair values would continue to exceed their carrying values. Therefore, no impairment exists on our goodwill. Adverse changes to U.S. corporate federal tax law. As mentionedour key considerations could, however, result in the section "Narrative Description of Business-Generalfuture impairments on our goodwill. See Item 1. "Business – Recent Business Developments – COVID-19" and Note 2 of the Partnership's consolidated financial statements included in4- Goodwill within Part IV, within Item 15. "Exhibits“Exhibits and Financial Statement Schedules", we are a non-taxable limited partnership,Schedules” which information is incorporated herein by reference

Long-Lived Assets
We assess our long-lived assets for impairment based on ASC 360-10-35 Property, Plant and income taxes owedEquipment – Overall – Subsequent Measurement when events or changes in circumstances indicate that the carrying value may not be recoverable. If the total of the estimated undiscounted future cash flows expected to be generated by that asset or asset group is less than the carrying value of the assets, an impairment charge is recognized for the excess of the carrying value over the fair value of the assets. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals as a resultconsidered necessary.
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Our management evaluates changes in our business and economic conditions and their implications for recoverability of our earnings arelong-lived assets’ carrying values when assessing these assets for impairments. The development of fair value estimates requires significant judgement in estimating future cash flows. In order to determine the responsibilityestimated future cash flows, management must make certain estimates and assumptions, which include the same factors we consider in our annual impairment test of goodwill such as:
discount rates and multiples;
commodity and capacity prices;
market supply and demand assumptions;
growth opportunities;
output levels;
competition from other companies;
regulatory changes; and
regulatory rate action or settlement.
Any changes we make to these estimates and assumptions could materially affect future cash flows, which could result to the recognition of an impairment loss in our partners, thereforeConsolidated statement of operations.
As of December 31, 2020, there were no indicators of impairment on our long-lived assets.
2018 Impairment on Bison’s long-lived assets
During the fourth quarter of 2018, Bison received an unsolicited offer from a customer regarding the termination of its contract, which represented approximately 60 percent of Bison’s contracted revenues. Bison and the customer mutually agreed to terms which included a cash payment to Bison of $95.4 million in December 2018 in exchange for the termination of all its contract obligations with Bison. Following the amendment of its tariff to enable this transaction, another customer executed a similar agreement to terminate its contract on Bison in exchange for a lump sum payment to Bison of approximately $2.0 million in December 2018. At the termination of the contracts, Bison was released from performing any future services with the two customers and as such, the amounts have beenreceived were recorded in revenue in 2018 and the Partnership's financial statementscash payments were used by the Partnership, together with other cash to pay in full its 2015 Term Loan Facility.
As disclosed under Part 1, Item 1. Business - Customers, Contracting and Demand section, natural gas is currently not flowing on Bison as a result of the 2017 Tax Act.

Our pipeline systems are regulated by the FERC, which approves the systems' rates onrelative cost advantage of WCSB and Bakken sourced gas versus Rockies production. Since its inception in January 2011, Bison has not experienced a cost-of-service basis and provides for a recoverydecrease in its revenue as its original ten-year contracts included ship-or-pay terms that resulted in payment to Bison regardless of our ultimate taxable owners' income tax expense and related balance sheet accounts as components of the maximum recourse rates that may be charged to customers. As a non-taxable entity,gas flows. In 2018, the Partnership does not recognize federal income tax expense nor has it established the related federal deferred income tax assets or liabilities. Income tax related expenses, benefits, assets, and liabilities attributable to regulated operations are the responsibility of the ultimate taxable owners of the Partnership and any adjustment to income tax accounts following the 2017 Tax Act must be evaluated by those owners.

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Any changes to the maximum recourse rates charged by our pipeline systems following the 2017 Tax Act will be reflected as those rates are revised through future rate proceedings individually unless superseded through other possible future action by the FERC. The Partnership cannot predict the ultimate impact of the 2017 Tax Act on future revenues of our pipeline systems.

At December 31, 2017, the Partnership considers its assessment of the impact of the 2017 Tax Act to be its best interpretation of available guidance. Should additional guidanceexpected a significant erosion on the impact of the 2017 Tax Act on non-taxable partnerships be provided by regulatory, tax and accounting authorities or other sourcescash flows Bison will generate in the future as a result of the advanced payments to Bison and related cancellation of the above contracts. The customer contract cancellations coupled with the persistence of unfavorable market conditions which have inhibited system flows prompted management to re-evaluate the carrying value of Bison’s long-lived assets.

Although the Partnership continues to explore alternative transportation-related options for Bison, management is currently unable to quantify the future cash flows of a viable operating plan beyond the remaining customer contracts’ expiry in January 2021, and accordingly the Partnership evaluated for impairment the carrying value of its property, plant and equipment on Bison at December 31, 2018. The Partnership will reviewcontinue to maintain Bison to stand ready for redevelopment and has concluded that the approach usedremaining obligations of Bison, primarily in the form of property tax obligations and adjust as appropriate.

operating and maintenance costs, exceed the net cash inflows that management currently considers probable and estimable.

Based on these factors, during the fourth quarter of 2018, the Partnership recognized a non-cash impairment charge of $537 million relating to the remaining carrying value of Bison’s property, plant and equipment after determining that it was no longer recoverable. The non-cash charge was recorded under the Impairment of long-lived assets line on the Consolidated statement of operations.
Equity Investments Goodwill and Long-Lived Assets

Equity Investments

We review our equity method investments when a significant event or change in circumstances has occurred that may have an adverse effect on the fair value of each investment. When such events or changes occur, we compare the estimated fair value to the carrying value of the related investment. We calculate the estimated fair value of an investment in an equity method investee using an income approach and market approach. The development of fair value estimates requires significant judgment including estimates of future cash flows which is dependent on internal forecasts, estimatesare determined using the same factors we consider in our annual impairment test of the long-termgoodwill such as:
discount rates and multiples;
commodity and capacity prices;
market supply and demand assumptions;
growth opportunities;
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output levels;
competition from other companies;
regulatory changes; and
regulatory rate of growth for the investee, estimates of the useful life over which cash flows will occur, and determination of weighted average cost of capital. The estimates used to calculate the fair value of an investee can change from year to year based on operating results and market conditions. action or settlement.
Changes in these estimates and assumptions could materially affect the determination of fair value and our assessment as to whether an investment in an equity method investee has suffered impairment.

If the estimated fair value of an investment is less than its carrying value, we are required to determine if the decline in fair value is other than temporary. This determination considers the aforementioned valuation methodologies, the length of time and the extent to which fair value has been less than carrying value, the financial condition and near-term prospects of the investee, including any specific events which may influence the operations of the investee, the intent and ability of the holder to retain its investment in the investee for a period of time sufficient to allow for any anticipated recovery in market value, and other facts and circumstances. If the fair value of an investment is less than its carrying value and the decline in value is determined to be other than temporary, we record an impairment charge.

Northern Border

Northern Border's 2013 settlement agreement required Northern Border to file for new rates no later than January 1, 2018. On December 4, 2017, Northern Border filed a rate settlement with FERC which precluded the need to file a general rate case by January 1, 2018. The 2017 Northern Border Settlement, which was approved by FERC on February 23, 2018, provides for tiered rate reductions beginning January 1, 2018, with no change to the underlying rate design. The 2017 Northern Border Settlement does not contain any moratorium and unless superseded by a subsequent rate case or settlement, recourse rates in effect at December 31, 2017, will decrease by 5.0% on January 1, 2018; by an additional 5.50% on April 1, 2018; and by an additional 2.0% beginning January 1, 2020 through December 31, 2023, when Northern Border will be required to establish new rates. This equates to an overall rate reduction of 12.5% by January 1, 2020 from the recourse rates in effect at December 31, 2017.

The 2017 Northern Border Settlement will provide Northern Border with rate stability over the longer term. We do not believe that the rate reduction as described above will have a material impact on the Partnership's results and, therefore, we do not believe the settlement outcome has negatively impacted the underlying value of our investment in Northern Border. The overall long-term market fundamentals of Northern Border continue to be positive due to its strategic footprint. Northern Border remains a key competitive pipeline and continues to operate at full capacity connecting major supply basins with communities in the Midwestern U.S. Accordingly, no impairment has been identified on our investment in Northern Border.

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Great Lakes

During the fourth quarter of 2015, we recorded an impairment charge of $199 million on our investment in Great Lakes. The impairment charge was the result of our determination that our investment in Great Lakes' long-term value had been adversely impacted by the changing natural gas flows in its market region and that other strategic alternatives to increase its utilization or revenue were no longer feasible. The impairment charge reduced the difference between the carrying value of our investment in Great Lakes and the underlying equity in the net asset to $260 million, and the difference represented the equity method goodwill remaining in our investment in Great Lakes relating to the Partnership's February 2007 acquisition of a 46.45 percent general partner interest in Great Lakes.

On October 30, 2017, Great Lakes filed a rate settlement with FERC to satisfy its obligations from its 2013 rate settlement for new rates to be in effect by January 1, 2018. The 2017 Great Lakes Settlement does not contain a moratorium provision and Great Lakes will be required to file for new rates no later than March 31, 2022, with new rates to be effective October 1, 2022. The 2017 Great Lakes Settlement, which was approved by FERC on February 22, 2018, decreased Great Lakes' maximum transportation rates by 27 percent effective October 1, 2017. At December 31, 2017, the estimation of fair value on our remaining equity investment in Great Lakes was completed and we concluded the fair value of our investment in Great Lakes has not materially changed from 2015.

The assumptions we used in the analysis related to the estimated fair value of our remaining equity investment in Great Lakes included the reduction in Great Lakes' rates effective October 1, 2017. The reduction in rates was offset by expected cash flows from the long-term transportation contract with the TransCanada, other revenue opportunities on the system and the settlement's elimination of the revenue sharing mechanism with its customers. Although evolving market conditions and other factors relevant to Great Lakes' long term financial performance have been positive, there is a risk that reductions in future cash flow forecasts or adverse changes in other key assumptions could result in an additional future impairment of the carrying value of our investment in Great Lakes.

Our key assumptions could be negatively impacted by near and long-term conditions including:

future regulatory rate action or settlement,

valuation of Great Lakes in future transactions,

changes in customer demand at Great Lakes for pipeline capacity and services,

changes in North American natural gas production in the major producing basins,

changes in natural gas prices and natural gas storage market conditions,

discount rates and multiples used, and

changes in other long-term strategic objectives.

As of December 31, 2017,2020, no impairment charge has been recorded related to any of our other equity investments.

Goodwill

We test goodwill for impairment annually based onASC 350 See also Item 1. "BusinessIntangiblesRecent Business DevelopmentsGoodwillCOVID-19" and Other, or more frequently if events or changes in circumstances lead us to believe it might be impaired. We assess qualitative factors to determine whether events or changes in circumstances indicate that goodwill might be impaired,Note 5- Equity Investments within Part IV, Item 15. “Exhibits and if we do not conclude that itFinancial Statement Schedules” which information is more likely than not that the fair value of the reporting unit is greater than the carrying value, we use a two-step process to test for impairment:

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We base these valuations on our projection of future cash flows which involves making estimates and assumptions about:

discount rates and multiples;

commodity and capacity prices;

market supply and demand assumptions;

growth opportunities;

output levels;

competition from other companies;

regulatory changes; and

regulatory rate action or settlement.

If our assumptions are not appropriate, or future events indicate that our goodwill is impaired, our net income would be impacted by the amount by which the carrying value exceeds the fair value of reporting unit, to the extent of the balance of goodwill.

At December 31, 2017 and 2016, we had $130 million of goodwill recorded on our consolidated balance sheet related to the North Baja and Tuscarora acquisitions. No impairment of goodwill existed at December 31, 2017.

Long-Lived Assets

We assess our long-lived assets for impairment based onASC 360-10-35 Property, Plant, and Equipment – Overall – Subsequent Measurement when events or changes in circumstances indicate that the carrying value may not be recoverable. If the total of the estimated undiscounted future cash flows expected to be generated by that asset or asset group is less than the carrying value of the assets, an impairment charge is recognized for the excess of the carrying value over the fair value of the assets. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals as considered necessary.

Our management evaluates changes in our business and economic conditions and their implications for recoverability of our long-lived assets' carrying values when assessing these assets for impairments. The development of fair value estimates requires significant judgement in estimating future cash flows. In order to determine the estimated future cash flows, management must make certain estimates and assumptions, which include, but are not limited to, demand, competition, contract renewals and other factors.

Any changes we make to these estimates and assumptions could materially affect future cash flows, which could result to the recognition of an impairment loss in our statement of income.

As of December 31, 2017, there were no indicators of impairment for our long-lived assets.

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reference.

Contingencies

Our pipeline systems'systems’ accounting for contingencies covers a variety of business activities, including contingencies forthat could arise from legal and environmental liabilities. Our pipeline systems accrue for these contingencies when their assessments indicate that it is probable that a liability has been incurred or an asset will not be recovered and an amount can be reasonably estimated in accordance withASC 450 – Contingencies.Contingencies. Our pipeline systems base their estimates on currently available facts and their estimates of the ultimate outcome or resolution. Actual results may differ from our pipeline systems'estimates or additional facts and circumstances cause us to revise our estimates resulting in an impact, positive or negative, on earnings and cash flow.

CONTINGENCIES

Legal

Various legal actions or governmental proceedings involving


As of December 31, 2020, our pipeline systemsequity investees are not aware of any contingent liabilities that have arisen in the ordinary course of business are pending. Our pipeline systems believe that the resolution of these issues will not have a material adverse impact on their results of operations or financial position. Please read Part I, Item 3. "Legal Proceedings" for additional information.

Environmental

We do not believe that compliance with existing environmental laws and regulations willwould have a material adverse effect on our pipeline systems. Becausetheir financial condition, results or operations or cash flows.

At December 31, 2020, the Partnership is not aware of any contingent liabilities that would have a material adverse effect on the inherent uncertainties as to the final outcome of proposed environmental regulations and legislation, we cannot estimate the range of possible costs, if any, from the proposals. Please read Part I, Item 1. "Business – Government Regulation" for additional information.

Greenhouse Gas Regulation

Through the EPA, the U.S. Government has imposed various measures related to GHG emissions, including emission monitoring and reporting requirements, preconstruction and operating permits for certain large stationary sources. The EPA has also proposed rules requiring the control of methane emissions from and leak detection and repair requirements for certain oil and natural gas production, processing, transmission and storage activities, though future implementation of these rules is uncertain at this time as a result of the recent change in U.S. Presidential Administrations. In any event, several states are also pursuing measures to regulate the emissions of GHGs, including implementation of cap and trade programs or carbon taxes. These final and proposed rules, as well as additional legislation or regulations for the control of GHG emissions could materially increase our operating costs, including our cost of environmental compliance by requiring us to install additional equipment and potentially purchase emission allowances or offset credits. The regulation or restriction of GHG emissions could also result in changes to the consumption and demand for natural gas. This could have either positive or adverse effects on our pipeline systems, ourPartnership’s financial position,condition, results of operations and future prospects. Please read Part I, Item 1. "Business – Government Regulation" for additional information.

or cash flows.


RELATED PARTY TRANSACTIONS

Please read Part III, Item 13. "Certain“Certain Relationships and Related Transactions, and Director Independence"Independence” and Note 17 within Part IV, Item 15. "Exhibits“Exhibits and Financial Statement Schedules"Schedules” for more information regarding related party transactions.

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Item 7A. Quantitative and Qualitative Disclosures About Market Risk

OVERVIEW

The Partnership and our pipeline systems are exposed to market risk, counterparty credit risk and liquidity risk. Our exposure to market risk discussed below includes forward-looking statements and is not necessarily indicative of actual results, which may not represent the maximum possible gains and losses that may occur, since actual gains and losses will differ from those estimated, based on actual market conditions.

Our primary risk management objective is to mitigate the impact of these risks on earnings and cash flow, and ultimately, unitholder value. We do not use financial instruments for trading purposes.

We record derivative financial instruments on the balance sheet as assets and liabilities at fair value. We estimate the fair value of derivative financial instruments using available market information and appropriate valuation techniques. Changes in the fair value of derivative financial instruments are recognized in earnings unless the instrument qualifies as a hedge and meets specific hedge accounting criteria. Qualifying derivative financial instruments'instruments’ gains and losses may offset the hedged items'items’ related results in earnings for a fair value hedge or be deferred in accumulated other comprehensive income for a cash flow hedge.

MARKET RISK

From time to time, and in order to finance our business and that of our pipeline systems, the Partnership and our pipeline systems issue debt to invest in growth opportunities and provide for ongoing operations. The issuance of floating rate debt exposes the Partnership and our pipeline systems to market risk from changes in interest rates which affect earnings and the value of the financial instruments we hold.


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Market risk is the risk that changes in market interest rates may result in fluctuations in the fair values or cash flows of financial instruments. We regularly assess the impact of interest rate fluctuations on future cash flows and evaluate hedging opportunities to mitigate our interest rate risk.


Certain of our financial instruments and contractual obligations with variable rate components, including the Partnership’s term loans, revolving credit facilities and the interest rate swap agreements that we use to manage our interest rate exposure, reference LIBOR, certain terms of which may cease to be published at the end of 2021 with full cessation expected by mid-2023. We continue to monitor developments and are preparing to address any necessary system and contractual changes while assessing the adoption of the standard market-proposed reference rates. We currently do not expect the impact to be material.

As of December 31, 2017,2020, the Partnership'sPartnership’s interest rate exposure resulted from our floating rate Senior Credit Facility, 2015 Term Loan Facility, GTN's Unsecured Term Facilityon North Baja’s unsecured term loan facility, PNGTS’ revolving credit facility and Tuscarora's Unsecured Term Facility, Tuscarora’s unsecured term loan facility, under which $435$98 million, or 184 percent, of our outstanding debt was subject to variability in LIBOR interest rates (2016 – $405(December 31, 2019 - $112 million or 216 percent).


As of December 31, 2017,2020, the variable interest rate exposure related to our 2013 Term Loan Facility was hedged by fixed interest rate swap arrangements and our effective interest rate was 2.313.26 percent. If interest rates hypothetically increased (decreased) on these facilities by one percent 100(100 basis points,points), compared with rates in effect at December 31, 2017, The Partnership's2020, our annual interest expense on its remaining debt with variable interest exposure would increase (decrease) and net income would decrease (increase) by approximately $4$1 million.


As of December 31, 2017, $152020, $130 million, or 634 percent, of Northern Border'sBorder’s outstanding debt was at floating rates (2016 – $181 million or 42 percent).rates. If interest rates hypothetically increased (decreased) by one percent 100(100 basis points,points), compared with rates in effect at December 31, 2017,2020, Northern Border'sBorder’s annual interest expense would increase (decrease) and its net income would decrease (increase) by approximately nil$1 million.

GTN's Unsecured


Northern Border’s and Iroquois’ Senior Notes, Northern Border's and Iroquois' Senior Notes, and all of Great Lakes'Lakes’ and GTN' s Notes, and the PNGTS' Series A Notes, represent fixed-rate debt;debt, and are therefore they are not exposed to market risk due to floating interest rates. Interest rate risk does not apply to Bison, and North Baja, as they currently doBison does not have any debt.

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The Partnership and our pipeline systems use derivatives as part of our overall risk management policy to assist in managing exposures to market risk resulting from these activities within established policies and procedures. We do not enter into derivatives for speculative purposes. Derivative contracts used to manage market risk generally consist of the following:


Swaps - contractual agreements between two parties to exchange streams of payments over time according to specified terms.

Options - contractual agreements to convey the right, but not the obligation, for the purchaser to buy or sell a specific amount of a financial instrument at a fixed price, either at a fixed date or at any time within a specified period.

The Partnership and our pipeline systems enter into interest rate swaps and option agreements to mitigate the impact of changes in interest rates.

The For details regarding our current interest rate swaps are structured such that the cash flows of the derivative instruments match those of the variable rate of interest on the 2013 Term Loan Facility. The Partnership hedged interest payments on the variable-rate 2013 Term Loan Facility with interest rate swaps maturing July 1, 2018, at a weighted average fixed interest rate of 2.31 percent. At December 31, 2017, the fair value of the interest rate swaps accounted for as cash flow hedges was an asset of $5 million (on both gross and net basis). At December 31, 2016, the fair value of the interest rate swaps accounted for as cash flow hedges was an asset of $1 million and a liability of $1 million (on a gross basis) and an asset of nil million (on a net basis). The Partnership did not record any amounts in net incomeother agreements related to ineffectiveness formitigation of impact on changes in interest rate hedges for the years ended December 31, 2017, 2016 and 2015. The net change in fair value of interest rate derivative instruments recognized in other comprehensive income was a gain of $5 million for the year ended December 31, 2017 (2016 - gain $2 million, 2015 – nil million). In 2017, the net realized loss related to the interest rate swaps was nil, and was included in financial charges and other (2016 – $3 million, 2015 – $2 million).

As discussed inrates, see Note 819- Fair Value Measurements within Part IV, Item 15. Exhibits“Exhibits and Financial Statement Schedules, the Partnership's 2013 Term Loan that was due July 1, 2018, was amended to extend the maturity period through October 2, 2022. As a result of this extension, the Partnership implemented an interest rate hedging strategy after the extension of maturity period and hedged the entire $500 million until its October 2, 2022 maturity using forward starting swaps at an average rate of 3.26 percent.

The Partnership has no master netting agreements, however, its contracts contain provisions with rights of offset. The Partnership has elected to present the fair value of derivative instruments with the right to offset on a gross basis in the balance sheet. Had the Partnership elected to present these instruments on a net basis, there would be net asset of $5 million as of December 31, 2017 and there would be no effect on the consolidated balance sheet as of December 31, 2016.

In anticipation of a debt refinancing in 2003, PNGTS entered into forward interest rate swap agreements to hedge the interest rate on its Senior Secured Notes due in 2018. These interest rate swaps were used to manage the impact of interest rate fluctuations and qualified as derivative financial instruments in accordance with ASC 815,Derivatives and Hedging. PNGTS settled its position with a payment of $20.9 million to counterparties at the time of the refinancing and recorded the realized loss in AOCI as of the termination date. The previously recorded AOCI" which information is currently being amortized against earnings over the life of the PNGTS' 5.90% Senior Secured Notes. At December 31, 2017, our 61.71 percent proportionate share of net unamortized loss on PNGTS included in AOCI was $1 million (2016 – $2 million). For the year ended December 31, 2017, 2016 and 2015, our 61.71 percent proportionate share of the amortization of realized loss on derivative instruments was $0.8 million for each year.

incorporated herein by reference.

COMMODITY PRICE RISK
The Partnership is influenced by the same factors that influence our pipeline systems. None of our pipeline systems own any of the natural gas they transport; therefore, they do not assume any of the related natural gas commodity price risk with respect to transported natural gas volumes.

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COUNTERPARTY CREDIT RISK AND LIQUIDITY RISK

Counterparty credit risk represents the financial loss that the Partnership and our pipeline systems would experience if a counterparty to a financial instrument failed to meet its obligations in accordance with the terms and conditions of the financial instruments with the Partnership or its pipeline systems.

The Partnership has exposure to counterparty credit risk in a number of areas including:
cash and cash equivalents;
accounts receivable and other receivables; and
the fair value of derivative assets
At December 31, 2020, we had no significant credit losses, no significant credit risk concentration and no significant amounts past due or impaired. Additionally, during year ended December 31, 2020 and at December 31, 2020, no customer accounted for more than 10 percent of our consolidated revenue and accounts receivable, respectively.
The Partnership and our pipeline systems have significant credit exposure to financial institutions as they hold cash deposits and provide committed credit lines and critical liquidity in the interest rate derivative market, as well as letters of credit to mitigate exposures to non-creditworthy customers.
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The Partnership closely monitors the creditworthiness of our counterparties, including financial institutions. However, we cannot predict to what extent our business would be impacted by uncertainty in energy commodity prices, including possible declines in our customers' credit worthiness.

Our maximum counterparty credit exposure with respect to financial instruments at the balance sheet date consists primarily of the carrying amount, which approximates fair value, of non-derivative financial assets, such as cash and cash equivalents and receivables, as well as the fair value of derivative financial assets. We review ourinstitutions, reviews accounts receivable regularly and, recordif needed, records allowances for doubtful accounts using the specific identification method. At December 31, 2017,However, we hadare not incurred any significantable to predict with certainty the extent to which our business could be impacted by the uncertainty surrounding the COVID-19 pandemic or the prolonged impact of low commodity prices, including possible declines in our counterparties' creditworthiness. Refer to Note 16 - Transactions with major customers within Part IV, Item 15. “Exhibits and Financial Statement Schedules” for more information. See also Part I, Item 1. "Business Customers, Contracting and Demand” section for more information on certain customers.


The factors described above have been incorporated by the Partnership as part of the "Measurement of credit losses on financial instruments" accounting standard that became effective on January 1, 2020 as described in more detail under Note 3 - Accounting pronouncements within Part IV, Item 15. “Exhibits and had no significant amounts past due or impaired. At December 31, 2017, we hadFinancial Statement Schedules”. The Partnership believes the factors as described above are considered to have a credit risk concentration on onenegligible impact considering the portfolio of counterparties in connection with our customers, Anadarko Energy Services Company, who owed us $4 million. This amount represented approximately 10 percent of our trade accounts receivable.

pipeline assets.

Liquidity risk is the risk that the Partnership and our pipeline systems will not be able to meet our financial obligations as they become due. Our approach to managingWe manage our liquidity risk isby continuously forecasting our cash flow on a regular basis to ensure that we always have sufficientadequate cash balances, cash flow from operations and credit facility availabilityfacilities to meet our operating, financing and capital expenditure obligations when due, under both normal and stressed conditions, without incurring unacceptable losses or damageconditions. Refer to "Liquidity and Capital Resources" section for more information about our reputation. liquidity.
At December 31, 2017,2020, the Partnership had a Senior Credit Facility of $500 million maturing in 2021 with anno outstanding balance. At December 31, 2020, PNGTS has a $125 million Revolving Credit Facility maturing in 2023 and has outstanding balance on this facility of $185 million. In addition,$25 million and, finally, at December 31, 2017,2020, Northern Border had a committed revolving bank line of $200 million maturing in 20202024 and $15$130 million was drawn. Both the Partnership'sThe Partnership’s Senior Credit Facility, PNGTS' revolving credit facility and the Northern Border $200 millionBorder’s credit facility have accordion features for additional capacity of $500 million, $50 million and $100$200 million respectively, subject to lender consent.

Item 8. Financial Statements and Supplementary Data

The financial statements required by this item are included in Part IV, Item 15 of this report on page F-1 and are incorporated herein by reference.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

None.

Item 9A. Controls and Procedures

EVALUATION OF DISCLOSURE CONTROLS AND PROCEDURES

As required by Rule 13a-15(e) under the Exchange Act, the management of our General Partner, including the principal executive officer and principal financial officer, evaluated as of the end of the period covered by this report the effectiveness of our disclosure controls and procedures. There are inherent limitations to the effectiveness of any system of disclosure controls and procedures, including the possibility of human error and the circumvention or overriding of the controls and procedures. The Partnership'sPartnership’s disclosure controls and procedures are designed to provide reasonable assurance of achieving their objectives. Based upon and as of the date of the evaluation, the management of our General Partner, including the principal executive officer and principal financial officer, concluded that the Partnership'sPartnership’s disclosure controls and procedures as of the end of the year covered by this annual report were effective to provide

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reasonable assurance that the information required to be disclosed by the Partnership in the reports that it files or submits under the Securities Exchange Act, of 1934, as amended (the "Exchange Act"), is (a) recorded, processed, summarized and reported within the time periods specified in the SEC'sSEC’s rules and forms and (b) accumulated and communicated to the management of our General Partner, including the principal executive officer and principal financial officer, to allow timely decisions regarding required disclosure.

Changes in Internal Control Over Financial Reporting

During the quarteryear ended December 31, 2017,2020, there was no change in the Partnership'sPartnership’s internal control over financial reporting that has materially impacted or is reasonably likely to materially impact our internal control over financial reporting.

MANAGEMENT'S

MANAGEMENT’S ANNUAL REPORT ON INTERNAL CONTROL OVER FINANCIAL REPORTING

Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Rule 13a-15(f) promulgated under the Securities Exchange Act of 1934.Act. Internal control over financial reporting, no matter how well designed, has inherent limitations and can only provide reasonable assurance with respect to the preparation and fair presentation of published financial statements. Under the supervision and with the participation of our management, including
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our principal executive officer and principal financial officer, we conducted an evaluation of the effectiveness of our internal control over financial reporting based on the framework in Internal Control – Integrated Framework issued in 2013 by the Committee of Sponsoring Organizations of the Treadway Commission.

Based on our assessment according to the above framework, management has concluded that our internal control over financial reporting was effective as of December 31, 2017 to provide2020 at providing reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with GAAP. ThereNo material weaknesses were no material weaknesses.

identified.

Our independent registered public accounting firm, KPMG LLP (KPMG), independently assessed the effectiveness of the Partnership'sPartnership’s internal control over financial reporting. KPMG has issued an attestation report concurring with management'smanagement’s assessment, which is included starting on page F-2 of the financial statements included in this Form 10-K.

Item 9B. Other Information

None.

Part

PART III

Item 10. Directors, Executive Officers and Corporate Governance

The Partnership is a limited partnership and as such has no officers, directors or employees. Set forth below is certain information concerning the directors and officers of the General Partner who manage the operations of the Partnership. Each director holds office for aPartnership as of February 24, 2021. Directors are appointed by the General Partner’s sole stockholder to serve one-year termterms or until his or her successor is earliertheir successors are appointed. All officers of the General Partner serve at the discretion of the board of directors of the General Partner which is an indirect wholly-owned subsidiary of TransCanada.

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Energy.
NameAge
NameAgePosition with General Partner

Karl JohannsonStanley G. Chapman, III5557Chair and Director
Jack F. Stark7067Independent Director
Malyn K. Malquist6865Independent Director
Walentin (Val) MiroshPeggy A. Heeg6172Independent Director
Brandon M. AndersonNathaniel A. Brown4445President, Principal Executive Officer and Director
M. Catharine DavisNadine E. Berge4853Director
Joel E. HunterGloria L. Hartl4851Director
Janine M. Watson5148Vice-President and General Manager
NathanielAlisa Williams37Vice-President, Taxation
Jon A. BrownDobson5441Secretary
Burton D. Cole46Controller
William C. Morris58Principal Financial Officer,
Nancy F. Priemer59Vice-President, Taxation
Jon A. Dobson51Secretary
William C. Morris55Vice-President and Treasurer

Mr. Johannson was appointedChapman has served as a director and Chair of the Board of Directors of the General Partner in March 2013.since January 1, 2019. Mr. Johannson'sChapman’s principal occupation is Executive Vice-President and President, CanadaU.S. and Mexico Natural Gas Pipelines andof TC Energy, for TransCanada a positionwhere he has heldled the U.S. natural gas business since May 1, 2017.April 2017 and the Mexico natural gas business since September 2020. He is accountableresponsible for TransCanada'sall pipeline operations and commercial activities across TC Energy's FERC-regulated transmission and storage assets as well as certain unregulated businesses. Mr. Chapman joined TC Energy as part of its acquisition of the Columbia Pipeline Group (Columbia) in July 2016 and served as Senior Vice President and General Manager of TC Energy’s FERC-regulated US natural gas pipelines and natural gas storagepipeline business in Canada and Mexico. Sincefrom July 2016 to April 2017. Prior to joining TransCanada in 1994,TC Energy, Mr. Johannson hasChapman held several other positions of increasing responsibility,at Columbia from December 2011 to July 2016, most recently as Executive Vice-President and President, Natural Gas PipelinesChief Commercial Officer. Before joining Columbia, Mr. Chapman held various positions of increasing responsibility with El Paso Corp and Tenneco Energy and was responsible for TransCanada from November 2012 to May 2017. Mr. Johannson has extensive senior management experience in the pipelinesvarious marketing and energy industriescommercial operations, as a result of his servicewell as an executive of TransCanadasupply, regulatory, business development and its affiliates.optimization activities. His experience in his prior roles at TransCanada provides him with intimate knowledge of the Partnership, including its strategies, operations and markets. Mr. Johannson's industry knowledge, management experience and leadership skills are highly valuable in assessingdeveloping and implementing our business strategies and assessing accompanying risks.

Mr. Stark was appointedhas served as a director and member of the audit and conflicts committee of the board of directors of the General Partner insince July 1999. Mr. Stark currently serves as the Chief Financial Officer of Generate Capital Inc., a clean energy financing company. He previously served as Chief Financial Officer of Imergy Power Systems, formerly Deeya Energy, an energy storage systems company, from December 2013 to July 2016. Mr. Stark was the Chief Financial Officer of BrightSource Energy Inc., a provider of technology for use in large-scale solar thermal power plansplants, from May 2007 to November 2013 and Chief Financial Officer of Silicon Valley Bancshares, a diversified financial services provider, from April 2004 to May 2007. Prior
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to May 2007, Mr. Stark held chief financial officer positions at Itron Inc., Silicon Energy Corporation and GATX Capital as well as senior management roles at PG&E Corporation for more than 20 years. Mr. Stark previously served as a director, Chairman of the Board and member of the audit committee of the board of directors of Washington Gas Light Company, a regulated natural gas utility. He also currently serves on the board of directors of ASUS,AltaGas Services (U.S.) Inc. (ASUS), a wholly-ownedwholly owned subsidiary of Alta Gas Services.AltaGas Ltd., and AltaGas Utility Holdings (U.S.) Inc., a wholly owned subsidiary of ASUS. From November 2015 to October 2017, he served as a director of TerraForm Power, Inc. and TerraForm Global, Inc., where he also served on the Compensationcompensation and Audit Committeesaudit committees of both companies. Through his roles as chief financial officer of numerous companies, Mr. Stark brings valuable financial expertise and management experience, including extensive knowledge regarding financial operations, investor relations, finance, energy risk management, regulatory affairs and knowledge of the natural gas industry. Mr. Stark'sStark’s prior audit committee experience further enhances his qualifications to serve as a member of our Board and our Audit Committee. His valuable management and financial expertise includes an understanding
Mr. Malquist has served as a director, Chair of the accountingaudit committee and financial matters thatmember of the Partnership and industry address on a regular basis.

Mr. Malquist was appointed a directorconflicts committees of the board of directors of the General Partner insince April 2011. Mr. Malquist is an executive with more than 30 years of experience serving in a variety of business, operations and financial roles. Mr. Malquist served on the Boardboard of Directorsdirectors and Audit Committeeaudit committee of Headwaters Incorporated ("Headwaters")(Headwaters), an NYSE-listed company that provides products, technologies and services in the light building products, heavy construction materials and energy industries, from January 2003 to May 2017, when Headwaters was acquired by Boral, Ltd. From September 2002 to March 2009, Mr. Malquist held various senior executive positions with Avista Corporation (Avista), an energy production, transmission and distribution company, including Senior Vice President from September 2002 to May 2006, Executive Vice President from May 2006 to March 2009, Mr. Malquist served as Executive Vice-President of Avista Corporation (Avista), energy production, transmission and distribution company. He also served as Chief Financial Officer of Avista from November 2002 to September 2008 and Treasurer from February 2004 to January 2006 and Senior Vice-President from September 2002 to May 2006. Prior to his employment at Avista, Mr. Malquist held various positions at Sierra Pacific Resources, (electricity provider), including President, Chief Executive Officer and Chief Operating Officer from January 1998 to April 2000 and

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various Senior Vice-President positions from 1994 to 1998. Through his extensive prior management experience, including serving as chief financial officer and chief executive officer of various energy companies, Mr. Malquist brings extensive knowledge regarding financial operations, energy risk management and knowledge of the energy industry to the Board of Directors and the Audit Committee. His valuable management and financial expertise includesinclude an understanding of the accounting and financial matters that the Partnership and industry address on a regular basis. In addition, Mr. Malquist'sMalquist’s experience in the energy industry is beneficial to the service he provides to the Board of Directors.

Mr. Mirosh


Ms. Heeg was appointed as a director and member of the audit and conflicts committee of the board of directors of the General Partner on September 15, 2020 to fill the vacancy created by the retirement of Walentin Mirosh from the TC PipeLines Board in August 2020. Ms. Heeg has over 30 years of experience in the energy and legal industries and government service. From November 2017 to January 2021, Ms. Heeg was a partner with, and member of the Executive Committee of, Reed Smith LLP, an international law firm with approximately 2,000 lawyers, providing strategic advice on a broad range of energy, complex governance, regulatory and business matters. From January 2004 to October 2017, she was a partner with Norton Rose Fulbright US LLP, a 3,800-attorney international law firm, practicing energy and corporate governance law and serving on the firm’s Executive Committee. Before joining Norton Rose, Ms. Heeg held several leadership roles at El Paso Corporation, most recently as Executive Vice President and General Counsel as well as a legal advisor to the Federal Energy Regulatory Commission. Ms. Heeg currently serves on the Board of WhiteWater Midstream, LLC, a private natural gas transmission company. She previously served as an independent director on the Boards of Directors of Eagle Rock Energy Partners, where she chaired the Nomination and Governance Committee and served on the Audit and Conflicts Committees, and Columbia Pipeline Partners LP, where she served on the Audit and Conflicts Committees. Ms. Heeg also previously served as a director of El Paso Tennessee Pipeline Company and as a commissioner on the Texas Lottery Commission, where she provided strategic, financial, risk and regulatory oversight of the agency. Ms. Heeg obtained a Bachelor of Arts degree and Juris Doctorate from the University of Louisville. She is a member of the State Bar of Texas, the American Bar Association and the Energy Bar Association.
Mr. Brown has served as President, Principal Executive Officer and a director of the General Partner in September 2004. Mr. Mirosh's principal occupation is President of Mircan Resources Ltd., (private consulting company), a position he has held since 2009. From April 2008 to December 2009, he was Vice-President and Special Advisor to the President and Chief Operating Officer of NOVA Chemicals Corporation (a commodity chemicals and plastics company). From July 2003 to April 2008, Mr. Mirosh was President of Olefins and Feedstocks, a division of NOVA Chemicals Corporation. Mr. Mirosh is also a director of Superior Plus Income Fund (energy services, specialty chemicals and construction products distribution) and Murphy Oil Corporation (an international oil and gas company). Mr. Mirosh's extensive experience in the natural gas transmission sector enhances the knowledge of the Board in this area of the industry. As a current and former executive and director of various companies, his breadth of experience is applicable to many of the matters routinely facing the Partnership. Moreover, Mr. Mirosh's experience and industry knowledge, complemented by an engineering and legal educational background, enable Mr. Mirosh to provide the Board of Directors and Audit Committee with executive counsel on a full range of business, financial, technical and professional matters.

Mr. Anderson was appointed President, Principal Executive Officer and a Director of the General Partner in January 2016. Mr. Anderson's principal occupation is Senior Vice President, U.S. Commercial for TransCanada and has main accountability on marketing, business development, rates, commercial operations, regulatory strategy, gas storage and asset optimization of all U.S Natural Gas assets. From July 2016- April 2017, Mr. Anderson was Senior Vice-President and General Manager, U.S. Natural Gas Storage, Midstream for TransCanada. From July 2015 to July 2016, Mr. Anderson was Senior Vice-President and General Manager, U.S. Natural Gas Pipelines for TransCanada. Mr. Anderson has over 20 years of energy industry experience and, since joining TransCanada in 2002, has held a variety of leadership positions in energy marketing and trading, business development, electricity, gas storage and TransCanada's Mexico pipeline operations. Mr. AndersonMay 1, 2018. He previously served as Senior Vice President and General Manager, Mexico Gas and Power from May 2013 to July 2015, Senior Vice President, Western Power and Gas Storage from January 2011 to May 2013 and Vice President, Gas Storage from March 2006 to January 2011.

Ms. Davis was appointed a director of the General Partner in April 2014. Ms. Davis' principal occupation is Vice-President, Law, Natural Gas Pipelines for TransCanada, a position she has held since October 2015. Ms. Davis is responsible for the regulatory, compliance, commercial, safety, environment, and business development law services provided to TransCanada's existing and proposed natural gas pipelines in Canada, the U.S., and Mexico. She is Chief Compliance Officer for the TransCanada Mainline and NGTL systems. From November of 2012 to October of 2015, Ms. Davis was the Vice-President, Law, Canadian Pipelines, Corporate Services Division for TransCanada, responsible for the regulatory, commercial, Aboriginal, land, safety, and environment law services provided to TransCanada's existing and proposed oil pipelines both in Canada and the U.S., and to its existing and proposed Canadian natural gas pipelines. From February 2007 to November 2012, Ms. Davis was Chief Compliance Officer and Associate General Counsel, and later Vice President, U.S. Pipelines Law for TransCanada's U.S. natural gas pipelines and storage companies. Prior to joining TransCanada in February 2007, Ms. Davis held various legal positions at Great Lakes Gas Transmission Company, most recently as Associate General Counsel and Chief Compliance Officer. Prior to 1992, she worked in the Federal Energy Regulatory Commission's Office of Administrative Law Judges, as a law clerk.

Mr. Hunter was appointed a director of the General Partner in April 2014. Mr. Hunter's principal occupation is Senior Vice-President, Capital Markets for TransCanada, a position he had held since December 2017. In his current position, Mr. Hunter is responsible for Corporate Finance, Corporate Planning, Trading and Financial Risk Management, Cash Management, Investor Relations and Financial Communication, and Treasury. Since joining TransCanada in 1997, Mr. Hunter has held a number of positions of increasing responsibility, most recently as Vice-President, Finance and Treasurer from July 2010 to December 2017 and Director of Corporate Finance from January 2008 to July 2010.

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Ms. Watson was appointed Vice-President and General Manager for the General Partner in October 2015. Her principal occupation is Director, LP Management & Pricing for TransCanada, a position she has held since October 2015. Ms. Watson has served in progressively senior positions in the natural gas pipeline and energy business segments of TransCanada since 1997. Prior to joining TransCanada, Ms. Watson was an attorney at the Calgary office of McCarthy Tétrault and clerked at the Alberta Court of Appeal.

Mr. Brown was appointed the Controller and Principal Financial Officer of the General Partner infrom May 2014.2014 to May 2018. His principal occupation is Vice-President, U.S. Natural Gas Pipelines Financial Services of TransCanada in whichUSA Services Inc., an indirect wholly owned subsidiary of TC Energy (TC USA), a position he has held since February 2018. In this position, he is responsible for the accounting, financial reporting, planning and budgeting of TransCanada'sTC Energy’s U.S. natural gas pipelines. Mr. Brown also served as Director of Financial Services for TC Energy’s U.S. Pipelines from May 2014 to February 2018 and Manager of accountingAccounting for TransCanada'sTC Energy’s U.S. Pipelines West from November 2009 to May 2014 and as Director of Financial Services for TransCanada's U.S. Pipelines from May 2014 to February 2018. In that capacity, Mr. Brown was responsible for accounting, financial reporting, planning and budgeting. He also provided regulatory accounting support for rate filings, settlement negotiations, and other regulatory proceedings.2014. Prior to joining TransCanada,TC Energy, Mr. Brown spent eight years in public accounting, most recently as an audit manager for Grant Thornton LLP and Ernst &Young.

& Young.

Ms. PriemerBerge has been a director of the General Partner since May 2018. Ms. Berge's principal occupation is Director, Corporate Compliance and Legal Operations with TC Energy, a position she has held since December 2014. Ms. Berge has served in several positions of increasing responsibility in the legal department since joining TC Energy in May 2005. Ms. Berge is responsible for directing the corporate compliance area across Canada, the US and Mexico, as well as leadership of operational matters for the TC Energy legal department in all three jurisdictions. Prior to joining TC Energy, Ms. Berge spent five years practicing law in the area of energy regulation. Ms. Berge brings valuable legal skills and experience to the Board of Directors.

Ms. Hartl, was appointed to the TC PipeLines Board on November 9, 2020, to fill the vacancy created by the retirement of Sean Brett from the Board in August 2020. Ms. Hartl's principal occupation is Vice-President, Risk Management of TC Energy, a position she has held since February 2019. In her current position, Ms. Hartl is responsible for oversight of risk management, including Canadian and U.S. insurance risk, counterparty risk, contract risk, market analytics and reporting. Since joining TC
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Energy as a Commercial Risk Specialist in January 2007, Ms. Hartl has held several positions of increasing responsibility, most recently as Director, Corporate Planning. We believe Ms. Hartl brings valuable skills and experience to the Board of Directors.
Ms. Watson has served as Vice-President and General Manager for the General Partner since October 2015. Her principal occupation is Director, LP Management & Pricing for TC Energy, a position she has held since October 2015. Ms. Watson joined TC Energy in 1997 and has served in progressively senior positions in the natural gas pipeline and energy business segments of TC Energy prior to her current position, most recently as Associate General Counsel, Energy Law. Prior to joining TC Energy, Ms. Watson practiced law at the Calgary office of McCarthy Tétrault and clerked at the Alberta Court of Appeal.
Ms. Williams has served as Vice-President, Taxation of the General Partner in February 2016. Ms. Priemer'ssince July 2019. Her principal occupation is Director, U.S. Natural Gas PipelinesIncome Taxation of TransCanada, a positionTC USA, in which role she has held sinceleads the U.S. tax group and is responsible for providing tax administration, tax planning, regulatory and accounting support for TC Energy’s U.S. subsidiaries. Ms. Williams joined TC Energy in July 2009. Prior to this position Ms. Priemer2018 as the Manager of Tax Reporting until she was a Taxappointed Director, of an affiliate locatedUS Taxation in Michigan, a position she held since 1998.July 2019. Prior to joining TransCanada,TC Energy, Ms. PriemerWilliams spent 18 yearsmore than a decade in both public accounting and industry.

private industry, most recently as Manager, Federal Income Tax for CITGO Petroleum Corporation from April 2018 to July 2018 and as Tax Manager, Income Tax Services for Enbridge Inc. (formerly Spectra Energy Corp) from May 2011 to April 2018.

Mr. Dobson was appointedhas served as Secretary of the General Partner insince May 2014, prior to which he served as Assistant Secretary of the General Partner sincefrom April 2012. Mr. Dobson'sDobson’s principal occupation is Director, U.S., Governance and Corporate and Securities Law of TC USA and Corporate Secretary for TransCanada'sTC Energy’s U.S. subsidiaries. Prior to joining TransCanadaTC Energy in January 2011, Mr. Dobson spent 18 years practicing law in various corporate and law firm positions, including Vice President and Assistant General Counsel of Nash Finch Company; Vice President, General Counsel and Secretary of BMC Industries, Inc.; and associate attorney at Lindquist & Vennum, PLLP.

Mr. Cole has served as Controller of the General Partner since July 2019. His principal occupation is Director, U.S. Accounting of TC USA, a position he has held since November 2018 and in which he leads the accounting and financial reporting group and supports the commercial, compliance and regulatory functions for TC Energy’s U.S. natural gas pipelines. Prior to joining TC Energy, Mr. Cole spent more than two decades in public accounting and private industry positions, including Vice President, Chief Accounting Officer of Talos Energy Inc. from April 2018 to September 2018, Vice President, Finance of Speargrass Oil & Gas, LLC from April 2017 to March 2018 and various positions of increasing responsibility at Spectra Energy Corp, most recently as General Manager, Credit and Enterprise Risk from January 2014 to March 2017 and Corporate Controller from March 2011 to January 2014.
Mr. Morris was appointedhas served as Vice-President, Principal Financial Officer and Treasurer of the General Partner since February 2018. Mr. Morris previously served as Vice President and Treasurer of the General Partner infrom November 2017. Mr. Morris served2017 to February 2018 and as Treasurer of the General Partner since 2012.from 2012 to November 2017. Mr. Morris'Morris’ principal occupation is Director, Finance and Assistant Treasurer of TransCanada,TC Energy, a position he has held since November 2015,2012. In this role, he is responsible for the development, execution and previous to that as Director, Corporate Finance since November 2012. From 2001 to 2012,monitoring of TC Energy’s financing strategy. Mr. Morris wasjoined TC Energy in 1996 and has held various positions of increasing responsibility, including manager, Risk Management, and Director of Risk Management for TransCanada and Manager, Risk Management for TransCanada for the previous five years.Management. Prior to joining TransCanada,TC Energy, Mr. Morris spent 12 years in both the public accounting and banking industries.

GOVERNANCE MATTERS

We are a limited partnership and a 'controlled company'‘controlled company’ as that term is used in NYSE Rule 303A.00, because all of our voting shares are owned by the General Partner. As such, the NYSE listing standards do not require that we or the General Partner have a majority of independent directors or a nominating or compensation committee of the General Partner'sPartner’s board of directors.

The NYSE listing standards require our principal executive officer to annually certify that he is not aware of any violation by the Partnership of the NYSE corporate governance listing standards. ThisThe most recent certification was provided to the NYSE on March 29, 2017.

July 14, 2020.

AUDIT COMMITTEE FINANCIAL EXPERT

The board of directors of the General Partner has determined that Malyn Malquist and Jack Stark are "audit“audit committee financial experts," are "independent"“independent” and are "financially sophisticated"“financially sophisticated” as defined under applicable SEC rules and NYSE Corporate Governance Standards. The board'sboard’s affirmative determination for both Malyn Malquist and Jack Stark was

78    TC PipeLines, LPAnnual Report2017



based on their respective education and extensive experience as chief financial officers for corporations that presented a breadth and level of complexity of accounting issues that are generally comparable to those of the Partnership.

CODE OF ETHICS AND CORPORATE GOVERNANCE GUIDELINES

The Partnership believes that director, management and employee honesty and integrity are important factors in ensuring good corporate governance. The directors, officers, employees and contractors of the General Partner are subject to TransCanada'sTC Energy’s Code of Business Ethics (COBE), which also has been adopted for the Partnership by our General Partner. Our COBE is published on our website at www.transcanada.com.www.tcpipelineslp.com. If any substantive amendments are made to the COBE for senior officers or if any waivers are granted, the amendment or waiver will be published on the Partnership'sPartnership’s website or filed in a report on Form 8-K.

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We also have a statement of Corporate Governance Guidelines that sets forth the expectation of how our Board of Directors should function and its position with respect to key corporate governance issues. A copy of the Corporate Governance Guidelines is available on our website at www.tcpipelineslp.com. If any amendments are made to the Corporate Governance Guidelines, the amendment will be published on the Partnership'sPartnership’s website or filed in a report on Form 8-K.

AUDIT COMMITTEE

The General Partner of the Partnership has a separately designated audit committee consisting of three independent Board members. The members of the committeeAudit Committee are Malyn Malquist, as Chair, Jack Stark and Walentin (Val) Mirosh.Peggy Heeg. All members of the Audit Committee meet the criteria for independence as set forth under the rulesand experience requirements of the SECNYSE and those of the NYSE.Exchange Act. None of the Audit Committee members have participated in the preparation of the financial statements of the Partnership or any of its subsidiaries at any time during the past three years. In addition, all members of the Audit Committee are able to read and understand fundamental financial statements, including a company's balance sheet, income statement and cash flow statement.

financially literate.

The Audit Committee has adopted a charter which specifically provides that it is responsible for the appointment, compensation, retention and oversight of the independent public accountants engaged in preparing and issuing the Partnership'sPartnership’s audit report, that the committeeAudit Committee has the authority to engage independent counsel and other advisors as it determines necessary to carry out its duties and for the committee to be responsible for establishing procedures for the receipt, retention and treatment of complaints regarding accounting, internal accounting controls or auditing matters, including procedures for the confidential, anonymous submission by employees of the General Partner of concerns regarding questionable accounting or auditing matters. The committeeAudit Committee has adopted TransCanada'sTC Energy’s Ethics Help-Line in fulfillment of its responsibility to establish a confidential and anonymous whistle blowing process. The toll freetoll-free Ethics Help-Line number and the audit committee'sAudit Committee’s charter are published on the Partnership'sPartnership’s website at www.tcpipelineslp.com.

COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION
The Board of Directors of our General Partner does not have a separate compensation committee, nor does it make any determination with respect to the amount of compensation to be paid to our executive officers.
EXECUTIVE SESSIONS OF NON-MANAGEMENT DIRECTORS

The independent directors of the General Partner meet at regularly scheduled executive sessions without management.management and non-independent directors. Jack Stark serves as the presiding director at those executive sessions. Persons wishing to communicate with the General Partner'sPartner’s independent directors may do so by writing in care of Secretary, Board of Directors, TC PipeLines, GP, Inc., 700 Louisiana Street, Suite 700, Houston, TX 77002, or via fax at 1.508.871.7047.

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SECTION 16(a) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE

Section 16(a) of the Exchange Act, as amended, requires the General Partner's directors and executive officers, and persons who beneficially own more than ten percent of the common units, to file reports of ownership and changes in ownership with the SEC and to furnish us with copies of all such reports. Based solely upon a review of the copies of the reports received by us, we believe that all such filing requirements were satisfied during 2017.

77002.

Item 11. Executive Compensation

COMPENSATION DISCUSSION AND ANALYSIS

We are a master limited partnership and are managed by the executive officers of our General Partner. We do not directly employ any of the individuals responsible for managing or operating our business. The executive officers of our General Partner are compensated directly by TransCanada.

TC Energy.

The compensation policies and philosophy of TransCanadaTC Energy govern the types and amount of compensation granted to each of the named executive officers. Since these policies and philosophy are those of TransCanada,TC Energy, we refer you to a discussion of those items as set forth in the Executive Compensation"Executive Compensation" section of the TransCanada "ManagementTC Energy “Management Information Circular"Circular” on the TransCanadaTC Energy website at www.tcpipelineslp.com.www.tcenergy.com. The TransCanada "ManagementTC Energy “Management Information Circular"Circular” is prepared by TransCanadaTC Energy pursuant to applicable Canadian securities regulations and is not incorporated into this document by reference or deemed furnished or filed by us under the Securities Exchange Act of 1934, as amended;Act; rather the reference is to provide our investors with an understanding of the compensation policies and philosophy of the ultimate parent of our General Partner.

The Board of Directors of our General Partner does not have a separate compensation committee, nor does it make any determination with respect to the amount of compensation to be paid to our executive officers. The Board of our General Partner does have responsibility for evaluating and determining the reasonableness of the total amount we are chargedcosts allocated to us for managerial, administrative and operational support provided by TransCanadaTC Energy and its affiliates, including our General Partner. We are allocated and reimburse TransCanadaTC Energy for a percentage of the compensation, including base salary and certain benefit and incentive compensation expenses related to the officers of our General Partner and employees of TransCanadaTC Energy who perform services on our behalf. The total compensation that are allocable to us vary for each officer or employee performing services on our behalf and are based on the estimated amount of time an employee devotes to matters related to our business as compared to the amount of time such employee devotes to matters related to the business of TransCanadaTC Energy and its other affiliates. The Board of Directors of our General Partner specifically approves the percentage allocation to the Partnership of the compensation of the executive officers of the General Partner on an annual basis. Please read Part III, Item 13. "Certain“Certain Relationships and Related Transactions, and Director Independence"Independence” for more information regarding this arrangement.

Compensation Committee Report

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Neither we, nor our General Partner, have a compensation committee. The board of directors of our General Partner has reviewed and discussed the Compensation"Compensation Discussion and AnalysisAnalysis" set forth above and based on this review and discussion has approved it for inclusion in this Form 10-K.

The board of directors of TC PipeLines GP, Inc:

    Brandon Anderson
    M. Catharine Davis
    Joel

Nadine E. Hunter
    Karl R. Johannson
Berge
Gloria L. Hartl
Nathaniel A. Brown
Stanley G. Chapman, III
Malyn K. Malquist

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    Walentin (Val) Mirosh

Peggy Heeg
Jack F. Stark

The following table summarizes the allocation percentages and amounts of the base salary allocatedand benefits charged to the Partnership in 2020, 2019 and paid by us in 2017, 2016 and 20152018, as applicable, for the individuals serving as our President and Principal Executive Officer, Controller andOfficers during 2020, Vice President, Principal Financial Officer and Treasurer and other executive officers of our General Partner for whom the salaries and benefits of more than $100,000 were allocatedallocations to us.

us exceeded $100,000.

Summary Compensation Table


Name and Principal Position
 
Year
 
Approximate
Percentage of
Time Devoted to
the Partnership
 
Total
Compensation
allocated to the
Partnership(a)
(in US dollars)
 

Brandon Anderson(b) 2017 30% 209,135 
President and Principal Executive Officer 2016 30% 199,920 

Janine Watson(c)(d) 2017 50% 170,244 
Vice-President and General Manager 2016 50% 155,782 

Nathan A. Brown 2017 35% 121,737 
Controller and Principal Financial Officer 2016 35% 112,663 
  2015 35% 114,098 

Jon A. Dobson 2017 60% 253,793 
    Secretary 2016 60% 239,226 
  2015 50% 208,051 

William C. Morris(d) 2017 50% 163,891 
Vice-President and Treasurer 2016 50% 152,956 
  2015 50% 162,881 

Name and Principal PositionYearApproximate
Percentage of
Time Devoted to
the Partnership
Total
Compensation
allocated to the
Partnership(a)
(in US dollars)
Nathaniel A. Brown(b)
202035 %176,594 
President and Principal Executive Officer201935 %177,755 
201835 %156,986 
William C. Morris (c) (e)
202050 %167,318 
Vice‑President, Principal Financial Officer and Treasurer201950 %172,165 
201850 %169,280 
Janine Watson(e)
202050 %180,388 
Vice‑President and General Manager201950 %185,613 
201850 %182,504 
Jon A. Dobson202053 %229,372 
Secretary201960 %238,074 
201860 %268,024 
Burton D. Cole(d)
202035 %133,216 
Controller and Principal Accounting Officer201935 %134,693 
2018— — 
(a)
Amounts presented are based on the Partnership's allocated portionamount of compensation paidreimbursement made by TransCanadathe Partnership to TC Energy representing base salary and benefits rate allocations from TC Energy to the named executive officerPartnership for the year indicated and is based on the percentage of the applicable officer’s time devoted to the Partnership.

The benefit reimbursement is based on the total monthly or annual base salary allocated to the Partnership multiplied by a factor applicable to benefits of US and Canadian employees.
(b)
Appointed as President and Principal Executive Officer effective May 1, 2018. The total compensation allocated to the Partnership in 2018 includes salary as Controller and Principal Financial Officer of the Partnership from January 1, 2016.

2018 - April 30, 2018.
(c)
Appointed as Vice – PresidentVice-President, Principal Financial Officer and Treasurer effective May 1, 2018. The total compensation allocated to the Partnership in October 2015.

2018 includes salary as Vice-President and Treasurer of the Partnership from January 1, 2018 - April 30, 2018.
(d)
Appointed as Controller, Principal Accounting Officer effective July 1, 2019. The total compensation presented here is his total compensation allocated to the Partnership in for the full year of 2019.
(e)Amounts presented have been converted to U.S. Dollars from Canadian dollars using the average exchange rate for the applicable year.

TC PipeLines, LP Annual Report 2020     73

Independent Director Compensation(a)



For the year ended December 31, 2017
(in dollars)
 
Cash
 
Deferred
Share Unit
Awards(b)
 
Total
   

Malyn K. Malquist(c)  177,500 177,500   
Jack F. Stark(d) 107,500 70,000 177,500   
Walentin (Val) Mirosh(e) 92,500 70,000 162,500   
For the year ended December 31, 2020
(in dollars)
Fees Earned
or Paid in
Cash
Deferred
Share Unit
Awards(b)
Total
Malyn K. Malquist(c)
95,000 80,000 175,000 
Jack F. Stark(d)
95,000 80,000 175,000 
Walentin (Val) Mirosh(e)
47,609 47,778 95,387 
Peggy Heeg(f)
23,261 23,261 46,522 
(a)
Employee directors do not receive any additional compensation for serving on the board of directors of our General Partner; therefore, no amounts are shown for Karl R. Johannson, Brandon Anderson, M. Catharine Davis and Joel E. Hunter.employee directors. Amounts paid as reimbursable business expenses to each director for attending board functions are not reflected in this table. Our General Partner does not consider the

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(b)
Amounts presented reflect the compensation expense recognized pursuant to FASB ASC Topic 718 related to the deferred share units (DSU)s(DSUs) granted during 20172020 under the DSU Plan.TC PipeLines GP, Inc. Deferred Share Unit Plan for Non-Employee Directors (2013) (DSU Plan). All of the DSUs granted to Messrs. Malquist, Stark and MiroshHeeg were outstanding at December 31, 2017.



2020.
At December 31, 2017,2020, Mr. Malquist, Mr. Stark and Mr. MiroshMs. Heeg held 13,028, 20,39724,381, 33,687 and 13,778809 DSUs, respectively. The fair market value of the DSUs held by Mr. Malquist, Mr. Stark and Mr. MiroshMs. Heeg at December 31, 20172020 was $691,766, $1,083,075$718,014, $992,076 and $731,615,$23,838, respectively. Amounts alsoThese amounts include amountsdistribution like payments credited to each independent director'sdirector’s DSU account equal to the distributions payable on the Partnership’s common units multiplied by the number of DSUs previously granted or credited.in the director’s account. In this regard, Mr. Malquist was credited 7401,668 DSUs, Mr. Stark was credited 1,3062,352 DSUs, and Mr. Mirosh was credited 8651,199 DSUs and Ms. Heeg was credited 3 DSUs. All DSUs credited during 20172020 were outstanding at December 31, 2017.

2020, except those that were credited to Mr. Mirosh.
As noted above, Mr. Mirosh retired from the TC PipeLines Board effective August 4, 2020. As a result, on September 2, 2020, the outstanding 23,329 DSUs at the time of retirement was paid to Mr. Mirosh amounting to $707,107.40.
(c)
Chair of the Audit Committee. Cash payments to Mr. Malquist elected to receive DSUs in lieu ofinclude the $55,000$70,000 annual cash retainer, the $15,000 Audit Committee Chair cash retainer and cash meeting attendance fees in 2017.

$10,000 of committee member retainer.
(d)
Lead Independent Director and Chair of the Conflicts Committee. Cash payments to Mr. Stark include the $55,000$70,000 annual cash retainer, $15,000 Conflicts Committee Chair retainer and $22,500$10,000 of meeting attendance fees.

committee member retainer.
(e)
Cash payments to Mr. Mirosh include the $55,000$70,000 annual cash retainer and $22,500$10,000 of meeting attendance fees.

committee member retainer. The amounts presented here represent Mr. Mirosh's prorated share in 2020.

(f)Cash payments to Ms. Heeg include the $70,000 annual cash retainer, and $10,000 of committee member retainer. The amounts presented here represent Ms. Heeg's prorated share in 2020.
Cash Compensation

In 2017,2020, each director who was not an employee of TransCanada,TC Energy, the General Partner or its affiliates (independent director) was entitled to a directors'directors’ retainer fee of $125,000$150,000 per annum, of which $70,000$80,000 was automatically granted in DSUs (see DSUsDeferred Share Units section below). The independent director appointed as Lead Independent Director and chairChair of the Conflicts Committee and the independent director appointed as chairChair of the Audit Committee were each entitled to an additional fee of $15,000 per annum, respectively.annum. Each independent director was also paid a feecommittee member retainer of $1,500$5,000 for attendance atparticipating in each meeting of the board of directors and a fee of $1,500 for attendance at each meeting of a committee of the board.committee. The independent directors are reimbursed for out-of-pocket expenses incurred in the course of attending such meetings. All fees are paid by the Partnership on a quarterly basis. The independent directors are permitted to elect to receive any portion of their cash fees in the form of DSUs pursuant to the DSU Plan.

Deferred Share Units

The DSU Plan was established in 2007 with the first grant occurring in January 2008. The DSU Plan was amended and restated in its entirety effective as of January 1, 2014. In 2017,2020, as part of the retainer fee, each independent director received anquarterly automatic grantgrants of DSUs withvalued at $20,000 each for a total annualized grant value of $70,000, which was paid quarterly.

$80,000.

At the time of grant, the value of a DSU is equal to the market value of aone common unit of the Partnership at the time the independent directorDSU is credited withto the units.independent director’s account. The value of a DSU when redeemed is equivalent to the market value of aone common unit of the Partnership at the time the redemption takes place. DSUs cannot be redeemed until the director ceases to be a member of the Board. Directors may redeem DSUs for cash or common units at their option. DSUs redeemed for common units would be purchased by the Partnership in the open market.

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market through a broker at their option.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

The following table sets forth information as of February 22, 201819, 2021 regarding the (i) beneficial ownership of our common units and shares of TransCanadaTC Energy by the General Partner'sPartner’s directors, the named executive officers and directors and executive officers as a group and (ii) beneficial ownership of our common units by all persons known by the General Partner to own beneficially at least five percent of our common units.

  Amount and Nature of Beneficial Ownership

 
  TC Pipelines, LP TransCanada Corporation 

Name and Business Address
 
Number of
Units(a)
 
Per cent
of Class(b)
 
Common
Shares
 
Per cent
of class
 

TransCan Northern Ltd(c)
450-1st Street SW
Calgary, Alberta T2P 5H1
 11,287,725 15.8   

TC Pipelines GP, Inc.(d)
450-1st Street SW
Calgary, Alberta T2P 5H1
 5,797,106 8.1   

OppenheimerFunds, Inc.(e)
Two World Financial Center
225 Liberty Street
New York, NY 10281
 9,005,426 12.89   

ALPS Advisors, Inc.(f)
1290 Broadway, Suite 1100
Denver, CO 80203
 4,378,065 6.27   

First Trust Portfolios LP(g)
120 East Liberty Drive, Suite 400
Wheaton, Illinois 60187
 4,040,374 5.78     

Energy Income Partners, LLC(h)
10 Wright Street
Westport, Connecticut 06880
 5,752,864 8.2     

Malyn K. Malquist(i) 14,281 *   

Jack F. Stark(j) 21,083 *   

Walentin (Val) Mirosh(k) 14,046 * 995 * 

Karl R. Johannson(l)   580,758 * 

Brandon M. Anderson(m)   120,575 * 

M. Catharine Davis(n)   36,533 * 

Joel E. Hunter(o)   65,562 * 

Nathaniel A. Brown    * 

Jon A. Dobson(p)   376 * 

William C. Morris(q)   18,254 * 

Janine M. Watson(r)   2,547 * 

Directors and Executive officers as a Group(s) (11 people) 49,410 * 825,600 * 

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Amount and Nature of Beneficial Ownership
TC PipeLines, LPTC Energy Corporation
Name and Business Address
Number of
Units(a)
Per cent
of Class(b)
Common
Shares
Per cent
of class
TransCan Northern Ltd(c)
450-1st Street SW
Calgary, Alberta T2P 5H1
17,084,831 24.0 — — 
ALPS Advisors, Inc.(d)
1290 Broadway, Suite 1100
Denver, CO 80203
6,072,740 8.52 — — 
First Trust Portfolios LP(e)
120 East Liberty Drive, Suite 400
Wheaton, Illinois 60187
6,004,796 8.42 
Energy Income Partners, LLC(f)
10 Wright Street
Westport, Connecticut 06880
7,888,173 11.0 
Invesco Ltd.(g)
1555 Peachtree Street NE, Suite
1,800
Atlanta, GA 30309
5,474,826 7.7 
Harvest Fund Advisors LLC(h)
100 W. Lancaster Avenue, Suite 200
Wayne, PA 19087
3,594,992 5.0 
Malyn K. Malquist(i)
25,381 *— — 
Jack F. Stark(j)
33,977 *— — 
Peggy Heeg(k)
809 *— — 
Stanley G. Chapman, III (l)
— — 217,504 *
Nadine E. Berge(m)
— — 363 *
Gloria L. Hartl(n)
— — 12,803 *
Nathaniel A. Brown(o)
— — 18,078 *
Burton D. Cole(p)
— — 62 *
Jon A. Dobson (q)
— — 376 *
William C. Morris(r)
— — 20,660 *
Janine M. Watson(s)
— — 354 *
Directors and Executive officers as a Group(t) (12 people)
60,167 *270,200 *
(a)
A total of 71,306,396 common units are issued and outstanding. For certain beneficial owners, the number of common units includes DSUs, which are a bookkeeping entry, equivalent to the value of a Partnership common unit, and do not entitle the holder to voting or other unitholder rights, other than the accrual of additional DSUs for the value of distributions. A director cannot redeem DSUs until the director ceases to be a member of the Board. Directors can then redeem their units for cash or common units.

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(b)
Any DSUs shall be deemed to be outstanding for the purpose of computing the percentage of outstanding common units owned by such person, but shall not be deemed to be outstanding for the purpose of computing the percentage of common units by any other person.

(c)
TransCan Northern Ltd. is a wholly-owned indirect subsidiary of TransCanada.

(d)
TC Energy. TransCan Northern Ltd. beneficially owns, through TC PipeLines GP, Inc. is a wholly-owned indirect subsidiary of TransCanada and also, 5,797,106 common units, as well as 11,287,725 common units which TransCan Northern Ltd. owns an effective two percent general partner interest of the Partnership.

(e)
directly.
(d)Based on a Schedule 13G/A filed with the SEC on February 5, 2018 by OppenheimerFunds, Inc. In this Schedule 13G/A, OppenheimerFunds, Inc. disclaims beneficial ownership, and has shared power to vote and to dispose of the 9,005,426 common units.

(f)
Based on a Schedule 13G/A filed with the SEC on February 6, 20189, 2021 by ALPS Advisors, Inc. In this Schedule 13G13G/A ALPS Advisors, Inc. disclaims beneficial ownership, and has shared power to vote and to dispose of the 4,378,0656,072,740 common units.

(g)
(e)Based on a Schedule 13G13G/A filed with the SEC on January 26, 201825, 2021 jointly by First Trust Portfolios LP,L.P., First Trust Advisors L.P. and The Charger Corporation. In this Schedule 13G, First Trust Portfolios LP, First Trust Advisors L.P. and The Charger Corporation have shared power to vote 4,036,8365,991,341 common units and shared power to dispose of 4,040,3746,004,796 common units, and First Trust Portfolios L.P., First Trust Advisors L.P. and The Charger Corporation. disclaim beneficial ownership of all of said common units.

(h)
(f)Based on a Schedule 13G/A filed with the SEC on February 14, 201816, 2021 by Energy Income Partners, LLC. In this Schedule 13G,13G/A, Energy Income Partners LLC has shared power to vote and to dispose of the 5,752,8647,888,173 common units.

(g)Based on a Schedule 13G/A filed with the SEC on February 12, 2021 by Invesco Ltd. In this Schedule 13G/A Invesco Ltd. d has sole power to vote 5,474,826 common units and sole power to dispose of 5,431,529 common units.
(h)Based on a Schedule 13D filed with the SEC on October 26, 2020 jointly by Harvest Fund Advisors LLC, Harvest Fund Holdco L.P., Blackstone Harvest Holdco L.L.C., Blackstone Intermediary Holdco L.L.C., Blackstone Advisory Partners L.P., Blackstone Advisory Services L.L.C., Blackstone Holdings I L.P., Blackstone Holdings I/II GP L.L.C., The Blackstone Group Inc., Blackstone Group Management L.L.C. and Stephen A. Schwarzman (collectively, the "Harvest Group"). In this Schedule 13D, the Harvest Group has power to vote and to dispose of 3,594,992 common units. The principal business address of each of the entities named in this paragraph, excluding Harvest Fund Advisors LLC, is c/o The Blackstone Group Inc., 345 Park Avenue, New York, New York 10154. The principal business address of Harvest Fund Advisors LLC is 100 W. Lancaster Avenue, Suite 200, Wayne, PA 19087.
(i)
Includes 13,28124,381 DSUs and 1,000 common units of the Partnership.

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(j)
Includes 20,79333,687 DSUs and 290 common units of the Partnership.

(k)
Includes 14,046 DSUs and 995 TransCanada common shares.

809 DSUs.
(l)
Includes 549,018184,062 options exercisable within 60 days for TransCanadaTC Energy common shares and 31,740 TransCanada33,442 TC Energy common shares held directly by Mr. Chapman.
(m)Includes 363 TC Energy common shares held in her Employee Share Savings Plan account.
(n)Includes 8,737 options exercisable within 60 days for TC Energy common shares, 1,060 TC Energy common shares indirectly held in her Registered Retirement Savings Plan and 3,006 TC Energy common shares held in her Employee Share Savings Plan account.
(o)Includes 15,313 options exercisable within 60 days for TC Energy common shares, 1,029 TC Energy common shares indirectly held in his 401(k) Plan, 36 TC Energy common shares held in his Employee Share SavingsStock Purchase Plan account.

(m)
Includes 111,030 options exercisable within 60 days for TransCanada common shares, 6,014 TransCanadaaccount and 1,700 TC Energy common shares held directly and 3,531 TransCanadaby Mr. Brown.
(p)Includes 62 TC Energy common shares held in his Employee Share SavingsStock Purchase Plan accounts.

(n)
account.
(q)Includes 35,968 options exercisable within 60 days for TransCanada common shares and 565 TransCanada common shares held in her TransCanada 401(k) and Savings Plan.

(o)
Includes 64,621 options exercisable within 60 days for TransCanada common shares, 441 TransCanada376 TC Energy common shares held in his Employee Share SavingsStock Purchase Plan accounts and 500 TransCanada shares held by Mr. Hunter's parents.

(p)
account.
(r)Includes 376 TransCanada common shares held in his TransCanada 401K and Savings Plan account.

(q)
Includes 8,724 TransCanada10,844 TC Energy common shares held in his Employee Share Savings Plan account and 9,530 TransCanada9,816 TC Energy common shares held jointly with his spouse.

(r)
(s)Includes 793 TransCanada354 TC Energy common shares held in her Employee Share Savings Plan account and 1,754 TransCanada common shares held by her spouse.

(s)
account.
(t)Includes 48,12058,877 DSUs and 1,290 common units of the Partnership, 7,009 TransCanada35,142 TC Energy common shares held directly, 9,530 TransCanada9,816 TC Energy common shares held with a spouse, 760,637208,112 options exercisable within 60 days for TransCanadaTC Energy common shares, 2,254 TransCanada common shares owned by immediate family members of which beneficial ownership of no common shares is disclaimed, and 45,229 TransCanada14,567 TC Energy common shares held in the TransCanadaTC Energy Employee Share Savings Plan, and 941 TransCanada474 TC Energy common shares held in the 401KTC Energy Employee Stock Purchase Plan, 1,060 TC Energy common shares indirectly held in a Registered Retirement Savings Plan and Savings1,029 TC Energy common shares indirectly held in a 401(k) Plan.

*
Less than one percent.

Item 13. Certain Relationships and Related Transactions, and Director Independence

As of February 22, 2018,24, 2021, subsidiaries of TransCanadaTC Energy own 17,084,831, or 23.96approximately 24 percent, of our outstanding common units, including 5,797,106 common units held by the General Partner. In addition, the General Partner owns 100 percent of our IDRs and an effectivea two percent general partner interest in the Partnership through which it manages and operates the Partnership. TransCanadaTC Energy also owns 100 percent of our Class B units. For more details regarding the Class B units, see Notes 7,Note 10 13 and 14 within Part IV, Item 15. "Exhibits“Exhibits and Financial Statement Schedules."

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Distributions and Payments to Our General Partner and Its Affiliates

The following table summarizes the distributions and payments made or to be made by us to our General Partner and its affiliates, which includes TransCanada,TC Energy, in connection with the ongoing operation and, if applicable, upon liquidation of the Partnership. These distributions and payments were determined by and among affiliated entities and, consequently, are not the result of arms-length negotiations.

Operational Stage

Operational Stage
Distributions of average
Cash to our General Partner and its affiliates
We generally make cash distributions of 98 percent to common unitholders, including our general partner with its affiliates as holders of an aggregate of 17,084,831 common units, and the remaining 2two percent to our General Partner. Additionally, the Class B units entitle TransCanadaTC Energy to receive an annual distribution based on 30 percent of GTN'sGTN’s annual distributions exceeding certain thresholds.thresholds and adjustments, after the Class B Reduction.

Payments to our General Partner and its affiliatesIf distributions exceed the minimum quarterly distribution and other higher target levels, our General Partner will be entitled to increasing percentages of the distributions, up to 25 percent of the distributions above the highest target level. We refer to the rights to the increasing distributions as "incentive“incentive distribution rights".rights.” For further information about distributions, please read Part II Item 5. "Market“Market for Registrant'sRegistrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities."

Withdrawal or removal of our General PartnerIf our General Partner withdraws or is removed, its General Partner interest and its incentive distribution rights will either be sold to the new general partner for cash or converted into common units, in each case for an amount equal to the fair market value of those interests.

Liquidation Stage

Liquidation Stage

LiquidationUpon our liquidation, the partners, including our General Partner, will be entitled to receive liquidating distributions according to their particular capital account balances. The Class B units rank equally with common units upon liquidation.

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Reimbursement of Operating and General and Administrative Expense

The Partnership does not have any employees. The management and operating functions are provided by the General Partner. The General Partner does not receive a management fee in connection with its management of the Partnership. The Partnership reimburses the General Partner for all costs of services provided, including the costs of employee, officer and director compensation and benefits, and all other expenses necessary or appropriate to the conduct of the business of, and allocable to, the Partnership. Such costs include (i) overhead costs (such as office space and equipment) and (ii) out-of-pocket expenses related to the provision of such services. The Partnership Agreement provides that the General Partner will determine the costs that are allocable to the Partnership in any reasonable manner determined by the General Partner in its sole discretion. Total costs charged to the Partnership by the General Partner were $4 million for the year ended December 31, 2017.

2020.

Cash Management Programs

Great Lakes has a cash management agreement with TransCanadaTC Energy whereby its funds are pooled with other TransCanadaTC Energy affiliates. The agreement gives Great Lakes the ability to obtain short-term borrowings to provide liquidity

TC PipeLines, LPAnnual Report2017    85



for its operating needs. At December 31, 20172020 and 2016,2019, Great Lakes has anhad outstanding receivablereceivables from this arrangement amounting to $64$27 million and $27$34 million, respectively.

Transportation Agreements

Great Lakes

Great Lakes earns significant transportation revenues from TransCanada and its affiliates, some of which are provided at discounted rates, negotiated rates and some at maximum recourse rates. Most recently, during 2017, Great Lakes signed a significant long-term contract with TransCanada that would allow TransCanada the abilityRelated Party

Refer to transport up to 0.711 billion cubic feet of natural gas per day on the Great Lakes system from the Manitoba/U.S. border to the U.S. border near Dawn Ontario beginning November 1, 2017. (Please see Part 1, Item 1. Business – "Recent Business Developments" for further details).

For the year ended December 31, 2017, Great Lakes earned 57 percent of its transportation revenues from TransCanada and its affiliates (2016 – 68 percent; 2015 – 71 percent). Additionally, Great Lakes earned approximately one percent of its total revenues as affiliated rental revenue in 2017 (2016 – 1 percent and 2015 – 1 percent).

At December 31, 2017, $20 million was included in Great Lakes' receivables in regards to the transportation contracts with TransCanada and its affiliates (December 31, 2016 – $19 million).

In 2017, Great Lakes operated under a FERC approved 2013 rate settlement that includes a revenue sharing mechanism that requires Great Lakes to share with its customers certain percentages of any qualifying revenues earned above certain ROEs. A refund of $7 million was paid to shippers in 2017 relating to the year ended December 31, 2016, of which approximately 86 percent was made to affiliates of Great Lakes. For the year ended December 31, 2017, Great Lakes has recorded an estimated revenue sharing provision amounting to $40 million and Great Lakes expects that a significant percentage of the 2017 revenue sharing refund will be to its affiliates.

Under the terms of the 2017 Great Lakes Settlement, beginning 2018, the revenue sharing was eliminated. Additionally, effective October 1, 2017, Great Lakes still charged customers rates in effect prior to the 2017 Great Lakes Settlement but only recognized revenue up to the amount of the new rates in the 2017 Great Lakes Settlement. The difference between these two amounts was recognized as a provision for rate refund (liability) on Great Lakes' balance sheet amounting to $8 million. Great Lakes expects that a significant percentage of the provision for rate refund will be to its affiliates as well. See Note 5 on Part IV within Item 15. "Exhibits and Financial Statement Schedules").

PNGTS

In connection with the PXP project, PNGTS entered into a precedent agreement with TransCanada for capacity on its mainline system. Please see Part 1, Item 1. Business – "Recent Business Developments" for further details.

Acquisitions

We have participated in several business acquisitions with TransCanada that were accounted for as transactions between entities under common control. For more details regarding the transactions' size, structure and terms, see Notes 717 within Part IV, Item 15. "Exhibits“Exhibits and Financial Statement Schedules."

Schedules,” which information is incorporated herein by reference.

Operating Agreements with Our Pipeline Companies

Our pipeline systems are operated by TransCanadaTC Energy and its affiliates pursuant to operating agreements. Under these agreements, our pipeline systems are required to reimburse TransCanadaTC Energy for their costs including payroll, employee benefit costs, and other costs incurred on behalf of our pipeline systems. Costs for materials, services and other charges that are third-party charges are invoiced directly to each of our pipeline systems.

86    TC PipeLines, LPAnnual Report2017



Total costs charged to our pipeline systems for the years ended December 31, 2017, 20162020, 2019 and 20152018 by TransCanada'sTC Energy’s subsidiaries and amounts payable to TransCanada'sTC Energy’s subsidiaries at December 31, 20172020 and 20162019 are summarized in Note 17 within Part IV, Item 15. "Exhibits“Exhibits and Financial Statement Schedules."

Schedules,” which information is incorporated herein by reference.

Other Agreements

Our pipeline systems currently have interconnection, operational balancing agreements, transportation and exchange agreements and/or other inter-affiliate agreements with affiliates of TransCanada.TC Energy. In addition, each of our pipeline systems currently has other routine agreements with TransCanadaTC Energy that arise in the ordinary course of business, including agreements for services and other transportation and exchange agreementagreements and interconnection and balancing agreements.

Relationship with our General Partner and TransCanadaTC Energy and Conflicts of Interest Resolution

Our Partnership Agreement contains specific provisions that address potential conflicts of interest between our General Partner and its affiliates, including TransCanada,TC Energy, on one hand, and us and our subsidiaries, on the other hand. Whenever such a conflict of interest arises, our General Partner will resolve the conflict. Our General Partner may, but is not required to, seek the approval of such resolution from the conflicts committee of the board of directors of our General Partner (Special Approval), which is comprised of independent directors.

Any conflict of interest and any resolution of such conflict of interest shall be conclusively deemed fair and reasonable if such conflict of interest or resolution is approved by Special Approval:

on terms no less favorable to the Partnership than those generally being provided to or available from unrelated third parties; or

fair to us, taking into account the totality of the relationships between the parties involved, including other transactions that may be particularly favorable or advantageous to us.

The General Partner may also adopt a resolution or course of action that has not received Special Approval.

In acting for the Partnership, the General Partner is accountable to us and the unitholders as a fiduciary. Neither the Delaware Revised Uniform Limited Partnership Act (Delaware Act) nor case law defines with particularity the fiduciary duties owed by general partners to limited partners of a limited partnership. The Delaware Act does provide that Delaware limited partnerships may, in their partnership agreements, restrict or expand the fiduciary duties owed by a general partner to limited partners and the partnership.

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In order to induce the General Partner to manage the business of the Partnership, the Partnership Agreement contains various provisions restricting the fiduciary duties that might otherwise be owed by the General Partner. The following is a summary of the material restrictions of the fiduciary duties owed by the General Partner to the limited partners:

The Partnership Agreement permits the General Partner to make a number of decisions in its "sole“sole discretion." This entitles the General Partner to consider only the interests and factors that it desires and it shall have no duty or obligation to give any consideration to any interest of, or factors affecting, the Partnership, its affiliates or any limited partner. Other provisions of the Partnership Agreement provide that the General Partner'sPartner’s actions must be made in its reasonable discretion.

The Partnership Agreement generally provides that affiliated transactions and resolutions of conflicts of interest not involving a required vote of unitholders must be "fair“fair and reasonable"reasonable” to the Partnership. In determining whether a transaction or resolution is "fair“fair and reasonable"reasonable” the General Partner may consider interests of all parties involved, including its own. Unless the General Partner has acted in bad faith, the action taken by the General Partner shall not constitute a breach of its fiduciary duty.

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The Partnership Agreement specifically provides that it shall not be a breach of the General Partner'sPartner’s fiduciary duty if its affiliates engage in business interests and activities in competition with, or in preference or to the exclusion of, the Partnership. Further, the General Partner and its affiliates have no obligation to present business opportunities to the Partnership.

The Partnership Agreement provides that the General Partner and its officers and directors will not be liable for monetary damages to the Partnership, the limited partners or assignees for errors of judgment or for any acts or omissions if the General Partner and those other persons acted in good faith.

The Partnership is required to indemnify the General Partner and its officers, directors, employees, affiliates, partners, members, agents and trustees (collectively referred to hereafter as the General Partner and others), to the fullest extent permitted by law, against liabilities, costs and expenses incurred by the General Partner and others. This indemnification is required if the General Partner and others acted in good faith and in a manner, they reasonably believed to be in, or (in the case of a person other than the General Partner) not opposed to, the best interests of the Partnership. Indemnification is required for criminal proceedings if the General Partner and others had no reasonable cause to believe their conduct was unlawful. Please read Part III, Item 10. "Directors,“Directors, Executive Officers and Corporate Governance"Governance” for additional information.

Director Independence

Please read Part III, Item 10. "Directors,“Directors, Executive Officers and Corporate Governance"Governance” for information about the independence of our General Partner'sPartner’s board of directors and its committees, which information is incorporated herein by reference in its entirety.

Item 14. Principal Accountant Fees and Services

The following table sets forth, for the periods indicated, the fees billed by the principal accountants:

Year ended December 31(thousands of dollars) 2017 2016 2015  

Audit Fees(a)(b)(c) 861 1,071 1,067  
Audit Related Fees     
Tax Fees(d)     
All Other Fees     

Total 861 1,071 1,067  

Year ended December 31 (thousands of dollars)
20202019
Audit Fees994 1,185 
Audit Related Fees — 
Tax Fees(b)
 — 
All Other Fees — 
Total994 1,185 
(a)
$200 thousand of the 2017 audit fees relate to ATM equity financing (2016 – $320 thousand and 2015 – $200 thousand).

(b)
$65 thousand of the 2017 audit fees relate to issuance of senior unsecured notes (2016 – none, 2015 – $150 thousand)

(c)
$26 thousand of 2015 audit fees related to advisory services for Class B issuance.

(d)
The Partnership did not engage its external auditors for any tax or other services in 2017, 20162020 or 2015.

2019.

AUDIT FEES

Audit fees include fees for the audit of annual GAAP financial statements, reviews of the related quarterly financial statements and related consents and comfort letters for documents filed with the SEC. Before our independent registered public accounting firm is engaged each year for annual audit and any non-audit services, these services and fees are reviewed and approved by our Audit Committee.

88    TC PipeLines, LPAnnual Report2017


The Audit Committee has a policy to pre-approve the engagement fees and terms of all audit, audit-related, tax and other non-audit services provided to the Partnership by the independent registered public accounting firm. All of the fees in the table above were approved in accordance with this policy. As part of the pre-approval process, the Audit Committee also evaluates all non-audit services to be provided by the independent registered public accounting firm to ensure the provision of the non-audit services is compatible with maintaining the independence of the independent registered public accounting firm under applicable U.S. federal securities laws and stock exchange rules. Pre-approval is detailed as to the particular service or category of services
78     TC PipeLines, LP Annual Report 2020

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and is subject to a specific budget or fee structure. The Audit Committee may delegate to one of its members the authority to pre-approve the engagement of the independent registered public accounting firm for permitted non-audit services, provided that such member is required to present the pre-approval of any permitted non-audit service to the full Audit Committee at its next meeting following any such pre-approval.

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 2020     79

Table of Contents

PART IV

Item 15. Exhibits and Financial Statement Schedules

(a)
(1)   Financial Statements
See "Index“Index to Financial Statements"Statements” set forth on Page F-1.

(2)
Financial Statement Schedules

All schedules are omitted because they are either not applicable or the required information is shown in the consolidated financial statements or notes thereto.

(3)
Exhibits
The exhibit list required by this Item is incorporated by reference to the Exhibit Index that follows the financial statements files as a part of this report.

No.Description

No.
Description
2.1*+

2.2*


Agreement for purchase and sale of membership interest dated as of May 15, 2013 between TC Continental Pipeline Holdings Inc., as Seller, and TC PipeLines Intermediate Limited Partnership, as Buyer (Exhibit 2.2 to TC PipeLines, LP's Form 8-K filed on May 15, 2013).]


2.3*3.1*


Agreement for Purchase and Sale of Partnership Interest in Iroquois Gas Transmission System, L.P. by and between TCPL Northeast Ltd. and TransCanada Iroquois Ltd., as Sellers and TC Pipelines Intermediate Limited Partnership as Buyer dated as of May 3, 2017 (Incorporated by reference from Exhibit 2.1 to TC PipeLines, LP's Form 8-K filed May 3, 2017).


2.3.1*


First Amendment to Purchase and Sale Agreement by and between TCPL Northeast Ltd. and TransCanada Iroquois Ltd., as Sellers and TC Pipelines Intermediate Limited Partnership as Buyer dated as of May 31, 2017 (Incorporated by reference from Exhibit 2.1.1 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


2.4*


Option Agreement Relating to Partnership Interest in Iroquois Gas Transmission System, L.P. by and between TransCanada Iroquois Ltd. and TC Pipelines Intermediate Limited Partnership as dated as of May 3, 2017 (Incorporated by reference from Exhibit 2.2 to TC PipeLines, LP's Form 8-K filed May 3, 2017).


2.5*


Agreement for Purchase and Sale of Partnership Interest in Portland Natural Gas Transmission System, by and between TCPL Portland Inc., as Seller and TC Pipelines Intermediate Limited Partnership as Buyer dated as of May 3, 2017 (Incorporated by reference from Exhibit 2.3 to TC PipeLines, LP's Form 8-K filed May 3, 2017).


3.1*


Third Amended and Restated Agreement of Limited Partnership of TC PipeLines, LP dated April 1, 2015 (Incorporated by reference from Exhibit 3.1 to TC PipeLines, LP's Form 8-K filed April 1, 2015).


3.1.1*


Amendment No. 1 to Third Amended and Restated Agreement of Limited Partnership of TC PipeLines, LP dated December 13, 2017 (incorporated by reference from Exhibit 3.1 to TC PipeLines, LP's Form 8-K filed December 15, 2017).

90    TC PipeLines, LPAnnual Report2017



3.2*




4.1*

3.2*
4.1*

4.2*

4.2*


4.3*

4.3*


4.4*

4.4*


4.5*

4.5*


4.6*

4.6*


4.7*

4.7


4.8*

10.1*


4.9*


Iroquois Gas Transmission, L.P. Senior Note Purchase Agreement dated as of April 27, 2010(Incorporated by reference from Exhibit 4.3 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


4.10*


Indenture dated as of May 30, 2000, between Iroquois Gas Transmission System, L.P.LP, the Lenders, and The Chase ManhattanSunTrust Bank, (Incorporated by reference from Exhibit 4.4 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


4.10.1*


Second Supplemental Indenture dated as of August 13, 2002, between Iroquois Gas Transmission System, L.P. and JPMorgan Chase Bank (formerly known as The Chase Manhattan Bank) (Incorporated by reference from Exhibit 4.4.1 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


4.11*


Credit Agreement dated as of June 26, 2008, between Iroquois Gas Transmission System, L.P. and JPMorgan Chase Bank, N.A. as administrative agent (Incorporated by reference from Exhibit 4.5 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


4.11.1*


Amendment No. 1 to Credit Agreement dated as of June 25, 2009, between Iroquois Gas Transmission System, L.P. and JPMorgan Chase Bank, N.A. as administrative agent for the lenders (Incorporated by reference from Exhibit 4.5.1 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.1*


Operating Agreement by and between Portland Natural Gas Transmission System and PNGTS Operating Co., LLC dated October 2, 1996 (Incorporated by reference from Exhibit 10.1 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.2*


Amended and Restated Operating Agreement by and between PNGTS Operating Co., LLC and 9207670 Delaware Inc. dated January 1, 2012 (Incorporated by reference from Exhibit 10.2 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).

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10.3*


Amended and Restated Operating Agreement by and between PNGTS Operating Co., LLC and 1120436 Alberta Ltd., Inc. dated January 1, 2012 (Incorporated by reference from Exhibit 10.3 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4*


Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated March 1, 1996 (Incorporated by reference from Exhibit 10.4 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.1*


First Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated May 23, 1996 (Incorporated by reference from Exhibit 10.4.1 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.2*


Second Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated October 23, 1996 (Incorporated by reference from Exhibit 10.4.2 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.3*


Third Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated March 17, 1998 (Incorporated by reference from Exhibit 10.4.3 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.4*


Fourth Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated March 31, 1998 (Incorporated by reference from Exhibit 10.4.4 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.5*


Fifth Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated September 30, 1998 (Incorporated by reference from Exhibit 10.4.5 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.6*


Sixth Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated June 4, 1999 (Incorporated by reference from Exhibit 10.4.6 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.7*


Seventh Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated June 28, 2001 (Incorporated by reference from Exhibit 10.4.7 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.8*


Eighth Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated September 29, 2003 (Incorporated by reference from Exhibit 10.4.8 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.9*


Ninth Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated December 3, 2003 (Incorporated by reference from Exhibit 10.4.9 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.10*


Tenth Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated February 11, 2005 (Incorporated by reference from Exhibit 10.4.10 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.11*


Eleventh Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated March 17, 2008(Incorporated by reference from Exhibit 10.4.11 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.4.12*


Twelfth Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated January 1, 2016(Incorporated by reference from Exhibit 10.4.12 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).

92    TC PipeLines, LPAnnual Report2017



10.4.13*


Thirteenth Amendment to Portland Natural Gas Transmission System Amended and Restated Partnership Agreement dated June 1, 2017 (Incorporated by reference from Exhibit 10.4.13 to TC PipeLines, LP's Form 10-Q filed August 3, 2017).


10.5*


First Amended and Restated General Partnership Agreement of Northern Border Pipeline Company by and between Northern Border Intermediate Limited Partnership and TC Pipelines Intermediate Limited Partnership dated April 6, 2006Lenders (Incorporated by reference to Exhibit 3.1 to Northern Border Pipeline Company's Form 8-K filed on April 12, 2006).


10.6*


Third Amended and Restated Agreement of Limited Partnership Agreement of Iroquois Gas Transmission, L.P. (Incorporated by reference from Exhibit 10.610.21 to TC PipeLines, LP'sLP’s Form 10-Q10-K filed August 3,on February 28, 2017).


10.7*


Transportation Service Agreement FT18966 between Great Lakes Gas Transmission Limited Partnership and TransCanada Pipelines Limited, effective August 4, 2017 (Incorporated by reference from Exhibit 10.1 to TC PipeLines, LP's Form 10-Q filed November 6, 2017).


10.8*10.1.1*


Second Amendment to TC PipeLines LP's July 1, 2013 Term Loan Agreement, dated September 29, 2017 (Incorporated by reference from Exhibit 99.1 to TC PipeLines, LP's Form 8-K filed October 3, 2017).


10.9*


Amendment No. 1 to TC PipeLines LP's September 30, 2015 Term Loan Agreement, dated September 29, 2017 (Incorporated by reference from Exhibit 99.2 to TC PipeLines, LP's Form 8-K filed October 3, 2017).


10.10*


80     TC PipeLines, LP Annual Report 2020

Table of Contents


10.11*No.

Description

10.2*

10.11.1*

10.2.1*
10.2.2*

10.12*

10.3
10.4

12.1


Computation of Ratio of Earnings to Fixed Charges.


21.110.5


21.1
Registrant (Incorporated by reference to Exhibit 21.1 to TC PipeLines,LP's Annual Report on Form 10-K for the year ended December 31, 2019).

23.1

23.1


23.2

23.2


23.3

23.3


31.1

31.1


31.2

31.2


32.1

32.1

TC PipeLines, LPAnnual Report2017    93



32.2




99.1*

99.1*
99.2*
99.3*
99.4*

99.2*

TC PipeLines, LP Annual Report 2020     81

Table of Contents

No.Description
99.5*
99.6
99.7
1, 2021.

99.3*


Transportation Term Sheet between Great Lakes Gas Transmission Limited Partnership and TransCanada PipeLines Limited (Incorporated by reference to Exhibit 99.3 to TC PipeLines, LP's Form 10-Q filed on May 4, 2017).


99.4*99.8




99.5*


Transportation Service Agreement FT18659FT18150 between Great Lakes Gas Transmission Limited Partnership and ANR Pipeline Company, effective date April November 1, 2017. (Incorporated by reference from Exhibit 99.3 TC PipeLines, LP's Form 10-Q filed August 3, 2017).2021.


99.6*

99.9
99.10
99.11
99.12
99.13
99.14
99.15
99.16
99.17
99.18
99.19
99.20
99.21
101The following materials from Exhibit 99.1 to TC PipeLines, LP'sLP’s Annual Report on Form 10-Q filed November 6, 2017).10-K for the year ended December 31, 2020 formatted in iXBRL (Inline eXtensible Business Reporting Language): (i) the Consolidated Statements of Income, (ii) the Consolidated Statements of Comprehensive Income, (iii) the Consolidated Balance Sheets, (iv) the Consolidated Statement of Cash Flows, (v) the Consolidated Statement of Changes in Partners’ Equity, and (vi) the Notes to Consolidated Financial Statements (Audited)
82     TC PipeLines, LP Annual Report 2020

Table of Contents


101.INSNo.


XBRL Instance Document.

Description

101.SCH


XBRL Taxonomy Extension Schema Document.


101.CAL104


Cover Page Interactive Data File (embedded within the Inline XBRL Taxonomy Extension Calculation Linkbase Document.


101.DEF


XBRL Taxonomy Definition Linkbase Document.


101.LAB


XBRL Taxonomy Extension Label Linkbase Document.


101.PRE


XBRL Taxonomy Extension Presentation Linkbase Document.

document)
*
Indicates exhibits incorporated by reference.

#
Management contract or compensatory plan or arrangement.

94    


+ Certain schedules have been omitted pursuant to Item 601(b)(2) of Regulation S-K. A copy of any omitted schedule will be furnished supplementally to the SEC on request.

TC PipeLines, LPAnnual Report2017

 2020     83

Table of Contents

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized on this 2624th day of February 2018.

2021.
TC PIPELINES, LP

(A Delaware Limited Partnership)

by its General Partner, TC PipeLines GP, Inc.



By:

By:
/s/ Brandon Anderson
Brandon Anderson
Nathaniel A. Brown
Nathaniel A. Brown
President

TC PipeLines GP, Inc. (Principal Executive Officer)



By:

By:/s/ Nathaniel A. Brown
Nathaniel A. Brown
Controller
William C. Morris
William C. Morris
Vice President and Treasurer
TC PipeLines GP, Inc. (Principal Financial Officer)

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons in the capacities and on the dates indicated.

Signature
Title
Date


Signature


Title


Date
/s/ Karl R. Johannson
Karl R. Johannson
ChairFebruary 26, 2018

/s/ Brandon Anderson

Brandon AndersonStanley G. Chapman III


President and Principal Executive OfficerChair


February 26, 201824, 2021

Stanley G. Chapman III
/s/ Nathaniel A. Brown
Principal Executive Officer and PresidentFebruary 24, 2021
Nathaniel A. Brown

Controller and
/s/ William C. MorrisPrincipal Financial Officer, Vice President and Treasurer

February 26, 201824, 2021

/s/ M. Catharine Davis
M. Catharine DavisWilliam C. Morris


Director


February 26, 2018

/s/ Joel E. Hunter
Joel E. Hunter


Director


February 26, 2018

/s/ Walentin (Val) Mirosh
Walentin (Val) MiroshNadine E. Berge


Director


February 26, 201824, 2021

Nadine E. Berge
/s/ Gloria L. HartlDirectorFebruary 24, 2021
Gloria L. Hartl
/s/ Peggy A. HeegDirectorFebruary 24, 2021
Peggy A. Heeg
/s/ Jack F. Stark
DirectorFebruary 24, 2021
Jack F. Stark

Director


February 26, 2018

/s/ Malyn K. Malquist
DirectorFebruary 24, 2021
Malyn K. Malquist

Director


February 26, 2018

84     TC PipeLines, LPAnnual Report2017    95

 2020

Table of Contents

TC PIPELINES, LP
INDEX TO FINANCIAL STATEMENTS

Page No.
Page No.
CONSOLIDATED FINANCIAL STATEMENTS OF TC PIPELINES, LP
F-2
F-2
F-3
F-4
F-4
F-5
F-5
F-6
F-6
F-7
F-7
F-8
F-8
F-9

FINANCIAL STATEMENTS OF NORTHERN BORDER PIPELINE COMPANY

F-35
F-31
F-36
F-32
F-37
F-33
F-37
F-34
F-38
F-35
F-39
F-36
F-40
F-37

FINANCIAL STATEMENTS OF GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP

F-51
F-45
F-52
F-46
F-53
F-47
F-54
F-48
F-49
F-55



TC PipeLines, LPAnnual Report2017    2020F-1


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REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The


Report of Independent Registered Public Accounting Firm

To the Board of Directors and Unitholders
of TC PipeLines GP, Inc., the General Partner of TC PipeLines, LP, and Partners
TC PipeLines, LP:


Opinions on the Consolidated Financial Statements and Internal Control Over Financial Reporting


We have audited the accompanying consolidated balance sheets of TC PipeLines, LP (a Delaware limited partnership) and subsidiaries (the Partnership) as of December 31, 20172020 and 2016,2019, the related consolidated statements of income,operations, comprehensive income (loss), changes in partners'partners’ equity, and cash flows for each of the years in the three-year period ended December 31, 2017,2020, and the related notes (collectively, the consolidated financial statements). We also have audited the Partnership'sPartnership’s internal control over financial reporting as of December 31, 2017,2020, based on criteria established inInternal Control – Integrated Framework (2013)issued by the Committee of Sponsoring Organizations of the Treadway Commission.


In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Partnership as of December 31, 20172020 and 2016,2019, and the results of its operations and its cash flows for each of the years in the three-year period ended December 31, 2017,2020, in conformity with U.S. generally accepted accounting principles. Also in our opinion, the Partnership maintained, in all material respects, effective internal control over financial reporting as of December 31, 2017,2020 based on criteria established inin Internal Control – Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission.


Basis for Opinion

Opinions


The Partnership'sPartnership’s management is responsible for these consolidated financial statements, for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management'sManagement’s Annual Report on Internal Control over Financial Reporting. Our responsibility is to express an opinion on the Partnership'sPartnership’s consolidated financial statements and an opinion on the Partnership'sPartnership’s internal control over financial reporting based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Partnership in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.


We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud, and whether effective internal control over financial reporting was maintained in all material respects.


Our audits of the consolidated financial statements included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide a reasonable basis for our opinions.


Definition and Limitations of Internal Control Over Financial Reporting


A company'scompany’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company'scompany’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company'scompany’s assets that could have a material effect on the financial statements.


Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

/s/ KPMG LLP




F-2     TC PipeLines, LP Annual Report 2020

Table of Contents
Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of a critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Qualitative assessment over goodwill for the Tuscarora and North Baja reporting units

As discussed in Notes 2 and 4 to the consolidated financial statements, the Partnership performs goodwill impairment testing on an annual basis and whenever events and changes in circumstances indicate that the carrying value of goodwill might exceed the fair value of a reporting unit. The Partnership performed a qualitative assessment over goodwill for their identified reporting units to determine whether there was a greater than 50 percent likelihood that the fair value of the reporting unit was less than its carrying value. The goodwill balance at December 31, 2020 was $71 million and specifically the goodwill balances for the Tuscarora reporting unit and North Baja reporting unit were $23 million and $48 million, respectively.

We identified the evaluation of the qualitative assessment over goodwill for the Tuscarora and North Baja reporting units as a critical audit matter. The qualitative assessments, specifically the market changes associated with the multiples and discount rates, required complex auditor judgment as minor changes to those considerations could have a significant impact on the assessment of the carrying value of goodwill.

The following are the primary procedures we performed to address the critical audit matter. We evaluated the design and tested the operating effectiveness of certain internal controls over the Partnership’s goodwill impairment process, including controls related to the development of the multiples and discount rates used in the qualitative assessment. We involved a valuation professional with specialized skills and knowledge who assisted in:

evaluating the Partnership’s determination of multiples by comparing to independently observed recent market transactions of comparable assets and using publicly available market data for comparable entities

evaluating the Partnership’s determination of applicable discount rates by comparing management’s selected discount rates to a discount rate range that was independently developed using publicly available market data for comparable companies.
/s/ KPMG LLP
We have served as the Partnership'sPartnership’s auditor since 2011.

Houston, Texas
TX
February 26, 2018

F-2    24, 2021

F-3TC PipeLines, LPAnnual Report2017

2020

Table of Contents

TC PIPELINES, LP
CONSOLIDATED BALANCE SHEETS


December 31 (millions of dollars)
 
2017
 
2016(a)
  

ASSETS      
Current Assets      
 Cash and cash equivalents 33 64  
 Accounts receivable and other (Note 20) 42 47  
 Inventories 8 7  
 Other 7 7  

  90 125  

Equity investments (Note 5) 1,213 918  
Plant, property and equipment, net (Note 6) 2,123 2,180  
Goodwill 130 130  
Other assets 3 1  

  3,559 3,354  


LIABILITIES AND PARTNERS' EQUITY

 

 

 

 

 

 
Current Liabilities      
 Accounts payable and accrued liabilities 31 29  
 Accounts payable to affiliates (Note 17) 5 8  
 Accrued interest 12 10  
 Distributions payable 1 3  
 Current portion of long-term debt (Note 8) 51 52  

  100 102  
Long-term debt (Note 8) 2,352 1,859  
Deferred state income taxes (Note 24) 10 10  
Other liabilities (Note 9) 29 28  

  2,491 1,999  
Common units subject to rescission (Note 10)  83  

Partners' Equity (Note 10)

 

 

 

 

 

 
 Common units 824 1,002  
 Class B units 110 117  
 General partner 24 27  
 Accumulated other comprehensive income (loss) (AOCI) (Note 11) 5 (2) 

Controlling interests 963 1,144  
Non-controlling interest 105 97  
Equity of former parent of PNGTS  31  

  1,068 1,272  

  3,559 3,354  

December 31 (millions of dollars)
20202019
ASSETS
Current Assets
Cash and cash equivalents200 83 
Accounts receivable and other (Note 20)
40 43 
Distribution receivable from Iroquois (Note 5)
0 14 
Inventories11 10 
Other6 
257 156 
Equity investments (Note 5)
1,070 1,098 
Property, plant and equipment, net (Note 7)
1,747 1,528 
Goodwill (Note 4)
71 71 
TOTAL ASSETS3,145 2,853 
LIABILITIES AND PARTNERS’ EQUITY
Current Liabilities
Accounts payable and accrued liabilities46 28 
Accounts payable to affiliates (Note 17)
7 
Accrued interest11 11 
Current portion of long-term debt (Note 8)
423 123 
487 170 
Long-term debt (Note 8)
1,768 1,880 
Deferred state income taxes (Note 2)
10 
Other liabilities (Note 9)
47 36 
2,312 2,093 
Partners’ Equity (Note 10)
Common units637 544 
Class B units95 103 
General partner16 14 
Accumulated other comprehensive income (loss) (AOCI) (Note 11)
(13)(5)
Controlling interests735 656 
Non–controlling interest98 104 
833 760 
TOTAL LIABILITIES AND PARTNERS' EQUITY3,145 2,853 
Contingencies (Note 22)
Variable Interest Entities (Note 23)
(Note 2)
Subsequent Events (Note 25)

(a)
Recast to consolidate PNGTS (Refer to Notes 2 and 7).

(Note 21)

The accompanying notes are an integral part of these consolidated financial statements.

F-4     TC PipeLines, LPAnnual Report2017    F-3

 2020

Table of Contents

TC PIPELINES, LP
CONSOLIDATED STATEMENTS OF OPERATIONS
Year ended December 31 (millions of dollars except per common unit amounts)
202020192018
Transmission revenues, net (Note 6)
399 403 549 
Equity earnings (Note 5)
170 160 173 
Impairment of long-lived assets (Note 7)
0 (537)
Impairment of goodwill (Note 4)
0 (59)
Operation and maintenance expenses(64)(71)(67)
Property taxes(26)(26)(28)
General and administrative(10)(8)(6)
Depreciation and amortization(89)(78)(97)
Financial charges and other (Note 12)
(73)(83)(92)
Net income (loss) before taxes307 297 (164)
Income taxes (Note 2)
(6)(1)
Net Income (loss)301 298 (165)
Net income attributable to non-controlling interests17 18 17 
Net income (loss) attributable to controlling interests284 280 (182)
Net income (loss) attributable to controlling interest allocation (Note 13)
Common units278 267 (191)
General Partner6 (4)
Class B units0 13 
284 280 (182)
Net income (loss) per common unit (Note 13) basic and diluted
$3.90 $3.74 $(2.68)
Weighted average common units outstanding (millions) – basic and diluted
71.3 71.3 71.3 
Common units outstanding, end of year (millions)
71.3 71.3 71.3 
TC PipeLines, LP Annual Report 2020F-5

Table of Contents
TC PIPELINES, LP
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME


Year ended December 31 (millions of dollars except per common unit amounts)
 
2017
 
2016(a)
 
2015(a)
  

Transmission revenues 422 426 417  
Equity earnings (Note 5) 124 97 97  
Impairment of equity-method investment (Note 5)   (199) 
Operation and maintenance expenses (67)(58)(61) 
Property taxes (28)(27)(27) 
General and administrative (8)(7)(9) 
Depreciation (97)(96)(95) 
Financial charges and other (Note 12) (82)(71)(63) 

Net income before taxes 264 264 60  

Income taxes (Note 24) (1)(1)(2) 

Net Income 263 263 58  

Net income attributable to non-controlling interests 11 15 21  

Net income attributable to controlling interests 252 248 37  

Net income attributable to controlling interest allocation (Note 13)        
Common units 219 211 (2) 
General Partner 16 11 3  
TransCanada and its subsidiaries 17 26 36  

  252 248 37  

Net income per common unit (Note 13) – basic and diluted(b) $3.16 $3.21 $(0.03) 

Weighted average common units outstanding(millions) – basic and diluted 69.2 65.7 63.9  

Common units outstanding, end of year(millions) 70.6 67.4 64.3  

(LOSS)

Year ended December 31 (millions of dollars)
202020192018
Net income (loss)301 298 (165)
Other comprehensive income (loss)
Change in fair value of cash flow hedges (Notes 11 and 19)(16)(13)(2)
Reclassification to net income of gains and losses on cash flow hedges (Notes 11 and 19)
7 (1)
Amortization of realized loss on derivative instrument (Notes 11 and 19)0 
Other comprehensive income (loss) on equity investments (Note 11)
1 (1)
Comprehensive income (loss)293 285 (162)
Comprehensive income attributable to non-controlling interests17 18 17 
Comprehensive income (loss) attributable to controlling interests276 267 (179)
The accompanying notes are an integral part of these consolidated financial statements.

F-4

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 2020

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TC PIPELINES, LP
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME


Year ended December 31 (millions of dollars)
 
2017
 
2016(a)
 
2015(a)
  

Net income 263 263 58  
Other comprehensive income        
 Change in fair value of cash flow hedges (Notes 11 and 19) 5 3   
 Reclassification to net income of gains and losses on cash flow hedges (Note 11)  (2)  
 Amortization of realized loss on derivative instrument (Notes 11 and 19) 1 1 1  
 Other comprehensive income on equity investments (Note 11) 1    

Comprehensive income 270 265 59  

Comprehensive income attributable to non-controlling interests 11 16 21  

Comprehensive income attributable to controlling interests 259 249 38  

(a)
Recast to consolidate PNGTS (Refer to Notes 2 and 7).

(b)
Net income per common unit prior to recast (Refer to Note 2).

CASH FLOWS

Year ended December 31 (millions of dollars)
202020192018
Cash Generated from Operations
Net income (loss)301 298 (165)
Depreciation and amortization89 78 97 
Impairment of long-lived assets (Note 7)
537 
Impairment of goodwill (Note 4)
59 
Amortization of debt issue costs reported as interest expense2 
Amortization of realized loss on derivative instrument (Note 19)
Equity earnings from equity investments (Note 5)
(170)(160)(173)
Distributions received from operating activities of equity investments (Note 5)
196 200 188 
Change in other long-term liabilities1 (1)(2)
Equity allowance for funds used during construction(10)(2)(1)
Change in operating working capital (Note 15)
4 (3)(3)
413 412 540 
Investing Activities
Investment in Great Lakes (Note 5)
(10)(10)(9)
Investment in Iroquois (Note 5)
(2)(4)
Distribution received from Northern Border as return of investment (Note 5)
0 50 
Distribution received from Iroquois as return of investment (Note 5)
29 10 
Capital expenditures(278)(75)(40)
Other(1)(1)
(262)(32)(35)
Financing Activities
Distributions paid (Note 14)
(189)(189)(218)
Distributions paid to Class B units (Notes 10 and 14)
(8)(13)(15)
Distributions paid to non-controlling interests(23)(22)(14)
Common unit issuance, net (Note 10)
40 
Long-term debt issued, net of discount (Note 8)
385 30 219 
Long-term debt repaid (Note 8)
(199)(136)(516)
Debt issuance costs(1)
(34)(330)(505)
Increase/(decrease) in cash and cash equivalents117 50 
Cash and cash equivalents, beginning of year83 33 33 
Cash and cash equivalents, end of year200 83 33 
Interest payments paid75 87 94 
State income taxes paid1 
Supplemental information about non-cash investing and financing activities
Accrued capital expenditures, net8 
The accompanying notes are an integral part of these consolidated financial statements.

TC PipeLines, LPAnnual Report2017    F-5

2020F-7

Table of Contents

TC PIPELINES, LP
CONSOLIDATED STATEMENTS OF CASH FLOWS


Year ended December 31 (millions of dollars)
 
2017
 
2016(a)
 
2015(a)
  

Cash Generated From Operations        
Net income 263 263 58  
Depreciation 97 96 95  
Impairment of equity-method investment (Note 5)   199  
Amortization of debt issue costs reported as interest expense (Note 12) 2 2 1  
Amortization of realized loss on derivative instrument (Note 19) 1 1 1  
Accrual of costs related to acquisition of 49.9% interest in PNGTS (Note 7)   2  
Equity earnings from equity investments (Note 5) (124)(97)(97) 
Distributions received from operating activities of equity investments (Note 5) 140 153 119  
Provision for deferred state income taxes (Note 24)   4  
Provision for rate refund-PNGTS (Note 2)   (101) 
Equity allowance for funds used during construction (1) (1) 
Change in operating working capital (Note 15) (2)(1)(20) 

  376 417 260  

Investing Activities        
Investment in Northern Border (Note 5) (83)   
Investment in Great Lakes (Note 5) (9)(9)(9) 
Distribution received from Iroquois as return of investment (Note 5) 5    
Acquisition of a 49.34 percent in Iroquois and an additional 11.81 percent in PNGTS (Note 7) (646)   
Acquisition of 49.9 percent interest in PNGTS (Note 7)  (193)  
Acquisition of the remaining 30 percent interest in GTN (Note 7)   (264) 
Capital expenditures (29)(29)(54) 
Other 1 1 1  

  (761)(230)(326) 

Financing Activities        
Distributions paid (Note 14) (284)(250)(228) 
Distributions paid to Class B units (Note 10 and 14) (22)(12)  
Distributions paid to non-controlling interests (5)(12)(21) 
Distributions paid to former parent of PNGTS (1)(9)(19) 
Common unit issuance, net (Note 10) 176 84 44  
Common unit issuance subject to rescission, net (Note 10)  83   
Equity contribution by the General Partner (Note 7)   2  
Long-term debt issued, net of discount (Note 8) 802 209 618  
Long-term debt repaid (Note 8) (310)(270)(425) 
Debt issuance costs (2)(1)(3) 

  354 (178)(32) 

Increase/(decrease) in cash and cash equivalents (31)9 (98) 
Cash and cash equivalents, beginning of year 64 55 153  

Cash and cash equivalents, end of year 33 64 55  

Interest payments paid 79 66 59  
State income taxes paid 2 2 2  

Supplemental information about non-cash investing and financing activities

 

 

 

 

 

 

 

 
Accrued capital expenditures 9  10  
Issuance of Class B units to TransCanada (Note 10)   95  
(a)
Recast to consolidate PNGTS (Refer to Notes 2 and 7).

The accompanying notes are an integral part of these consolidated financial statements.

F-6    TC PipeLines, LPAnnual Report2017


TC PIPELINES, LP

CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS'PARTNERS’ EQUITY

 
  
 
  
  
 
  
  
 
Accumulated
Other
Comprehensive
Income
(Loss)(a)(c)

  
  
  
  
 
 
Limited Partners

  
  
  
  
  

(millions of units)
(millions of dollars)

 
General
Partner

 
Non-Controlling
Interest(d)

  
 
Total
Equity(d)

  
 
PNGTS(c)(d)

  
 Common Units
 Class B Units
  

Partners' Equity at
December 31, 2014(d)
 63.6  1,325    29 (5)323 146 1,818  
Issuance of Class B Units (Note 7 and 10)    1.9  95     95  
Net income (loss)(d)   (2)  12 3  21 24 58  
Other Comprehensive Loss, net(d)        1    1  
ATM Equity Issuance, net (Note 10) 0.7  43    1    44  
Acquisition of the remaining interest in GTN (Note 7)   (124)   (3) (232) (359) 
Equity Contribution (Note 7)       2    2  
Distributions(d)   (221)   (7) (21)(19)(268) 

Partners' Equity at December 31, 2015(d) 64.3  1,021 1.9  107 25 (4)91 151 1,391  

Net income(d)   211   22 11  15 4 263  
Other Comprehensive Income, net(d)        2 1  3  
Common unit issuance subject to rescission, net(b) (Note 10) 1.6  81    2     83  
Reclassification of common unit issuance subject to rescission, net(b) (Note 10)   (81)   (2)   (83) 
ATM Equity Issuance, net (Note 10) 1.5  82    2    84  
Acquisition of 49.9 percent interest in PNGTS (Note 7)   (72)   (1)    (73) 
Distributions(d)   (240)  (12)(10) (10)(4)(276) 
Former parent carrying amount of PNGTS(d)          (120)(120) 

Partners' Equity at
December 31, 2016(d)
 67.4  1,002 1.9  117 27 (2)97 31 1,272  

Net income   219   15 16  11 2 263  
Other comprehensive income        7   7  
ATM equity issuances, net (Note 10) 3.2  173    3    176  
Reclassification of common units no longer subject to rescission (Note 10)   81    2    83  
Acquisition of interests in PNGTS and Iroquois (Note 7)   (383)   (8)  (32)(423) 
Distributions   (268)  (22)(16) (3)(1)(310) 

Partners' Equity at
December 31, 2017(d)
 70.6  824 1.9  110 24 5 105  1,068  

LimitedPartnersGeneral
Partner
Accumulated
Other
Comprehensive
Income (Loss) (a)
Non-Controlling
Interest
Total
Equity
Common UnitsClass B Units
(millions of units)(millions of dollars)(millions of units)(millions of dollars)(millions of dollars)(millions of dollars)(millions of dollars)(millions of dollars)
Partners’ Equity at December 31, 201770.6 824 1.9 110 24 105 1,068 
Net income— (191)— 13 (4)— 17 (165)
Other comprehensive income— — — — — — 
ATM equity issuances, net (Note 10)
0.7 39 — — — — 40 
Distributions— (210)— (15)(8)— (14)(247)
Partners' Equity at December 31, 201871.3 462 1.9 108 13 108 699 
Net income (loss)— 267 — — 18 298 
Other comprehensive income— — — — — (13)— (13)
Distributions— (185)— (13)(4)— (22)(224)
Partners' Equity at December 31, 201971.3 544 1.9 103 14 (5)104 760 
Net income 278  0 6  17 301 
Other comprehensive income     (8) (8)
Distributions (185) (8)(4) (23)(220)
Partners' Equity at December 31, 202071.3 637 1.9 95 16 (13)98 833 
(a)
LossesGains / losses related to cash flow hedges reported in AOCIaccumulated other comprehensive income (loss) (AOCI) and expected to be reclassified to net income in the next 12 months are estimated to be $2a loss of $9 million. These estimates assumeThis estimate assumes constant interest rates over time; however, the amounts reclassified will vary based on actual value of interest rates at the date of settlement.

(b)
These units are treated as outstanding for financial reporting purposes.

(c)
Equity of Former Parent of PNGTS.

(d)
Recast to consolidate PNGTS (Refer to Notes 2 and 7).

The accompanying notes are an integral part of these consolidated financial statements.

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TC PIPELINES, LP
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

NOTE 1 ORGANIZATION

TC PipeLines, LP and its subsidiaries are collectively referred to herein as the Partnership. The Partnership, which owns its pipeline assets directly as noted in the table below, was formed by TransCanada PipeLines Limited, a wholly-ownedwholly owned subsidiary of TransCanadaTC Energy Corporation (TransCanada(TC Energy Corporation together with its subsidiaries collectively referred to herein as TransCanada)TC Energy), to acquire, own and participate in the management of energy infrastructure assets in North America.

The Partnership owns interests in the following natural gas pipeline systems through three intermediate limited partnerships (ILPs), TC GL Intermediate Limited Partnership, TC PipeLines Intermediate Limited Partnership and TC Tuscarora Intermediate Limited Partnership:






PipelineLengthDescriptionOwnership

Pipeline
LengthDescriptionOwnership
Gas Transmission Northwest LLC (GTN)GTN1,377 milesExtends between an interconnection near Kingsgate, British Columbia, Canada at the Canadian border to a point near Malin, Oregon at the California border and delivers natural gas to the Pacific Northwest and to California.100 percent

Bison Pipeline LLC (Bison)


Bison303 miles

Extends from a location near Gillette, Wyoming to Northern Border's pipeline system in North Dakota. Bison can transport natural gas from the Powder River Basin to Midwest markets.


100 percent


North Baja Pipeline, LLC (North Baja)

86 miles


Extends between an interconnection with the El Paso Natural Gas Company pipeline near Ehrenberg, Arizona and an interconnection with a natural gas pipeline near Ogilby, California on the Mexican border transporting natural gas in the southwest. North Baja is a bi-directional pipeline.


100 percent


Tuscarora Gas Transmission Company (Tuscarora)


Tuscarora305 miles

Extends between the GTN pipeline near Malin, Oregon to its terminus near Reno, Nevada and delivers natural gas in northeastern California and northwestern Nevada.


100 percent


Northern Border Pipeline Company (Northern Border)

1,412 miles


Extends between the Canadian border near Port of Morgan, Montana to a terminus near North Hayden, Indiana, south of Chicago. Northern Border is capable of receiving natural gas from Canada, the Bakken, the Williston Basin and Rocky Mountain area for deliveries to the Midwest. ONEOK Partners, L.P.Northern Border Pipeline Company Holdings LLC owns the remaining 50 percent of Northern Border.


50 percent


Portland Natural Gas Transmission System (PNGTS)


PNGTS295 miles

Connects with the TQM at the Canadian border to deliver natural gas to customers in the U.S. northeast. Northern New England Investment Company, Inc. owns the remaining 38.29 percent of PNGTS. The 295-mile pipeline includes a 107 miles of jointly owned pipeline facilities (the Joint Facilities) with MNE. The Joint Facilities extend from Westbrook, Maine to Dracut, Massachusetts and PNGTS owns approximately 32%32 percent of the undivided ownership interest based on contractually agreed upon percentages. The Joint Facilities are maintained and operated by MNOC, a wholly owned subsidiary of MNE. MNE is a subsidiary of Enbridge Inc.


61.71 percent(a)


Great Lakes Gas Transmission Limited Partnership (Great Lakes)

2,115 miles


Connects with the TransCanadaTC Energy Mainline at the Canadian border near Emerson, Manitoba, Canada and St. Clair, Michigan, near Detroit. Great Lakes is a bi-directional pipeline that can receive and deliver natural gas at multiple points along its system. TransCanadaTC Energy owns the remaining 53.55 percent of Great Lakes.


46.45 percent


Iroquois Gas Transmission System, L.P (Iroquois)


Iroquois416 miles

Extends from the TransCanadaTC Energy Mainline system near Waddington, New York to deliver natural gas to customers in the U.S. northeast. The remaining 50.66 percent is owned by TransCanadaby: TC Energy (0.66 percent), Dominion Midstream (25.93 percent) and Dominion Resources (24.07Berkshire Hathaway (50 percent). Iroquois is maintained and operated by a subsidiary of Iroquois.


49.34 percent(b)

(a)
On June 1, 2017, the Partnership acquired an additional 11.81 percent from TransCanada resulting in 61.71 percent ownership in PNGTS. (Refer to Note 7).

(b)
Effective June 1, 2017 (Refer to Note 7).

F-8    TC PipeLines, LPAnnual Report2017



The Partnership is managed by its General Partner, TC PipeLines GP, Inc. (General Partner), an indirect wholly-ownedwholly owned subsidiary of TransCanada.TC Energy. The General Partner provides management and operating services to the Partnership and is reimbursed for its costs and expenses. The General Partner owns 5,797,106 of our common units, 100 percent of our IDRsIncentive Distribution Rights (IDRs) and an effective twoa 2 percent general partner interest in the Partnership at December 31, 2017. TransCanada2020. TC Energy also indirectly holds an additional 11,287,725 common units, for a total ownership of 24.2approximately 24 percent of our outstanding common units and 100 percent of our Class B units at December 31, 20172020 (Refer to Note 10).

Planned Merger with TC Energy
On December 14, 2020, the Partnership, the General Partner, TC Energy, TransCan Northern Ltd., a Delaware corporation (TC Northern), TransCanada PipeLine USA Ltd., a Nevada corporation (TC PipeLine USA), and TCP Merger Sub, LLC, a Delaware limited liability company and an indirect wholly owned subsidiary of TC Energy (Merger Sub), entered into an Agreement and Plan of Merger (the TC Energy Merger Agreement). Pursuant to the TC Energy Merger Agreement, Merger Sub will be merged with and into the Partnership (TC Energy Merger), with the Partnership continuing as the sole surviving entity and an indirect, wholly owned subsidiary of TC Energy.
Subject to the terms and conditions set forth in the TC Energy Merger Agreement, at the effective time of the TC Energy Merger, each of the Partnership’s common units representing the limited partner interests in the Partnership issued and outstanding
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immediately prior to the effective time of the TC Energy Merger to Unaffiliated TCP Unitholders, will be cancelled in exchange for 0.70 shares of TC Energy’s common shares.
The transaction is expected to close late in the first quarter subject to the approval by the holders of a majority of outstanding common units of the Partnership and customary regulatory approvals. Upon closing, the Partnership will be wholly owned by TC Energy and will cease to be a publicly-held master limited partnership.

NOTE 2 SIGNIFICANT ACCOUNTING POLICIES

The accompanying consolidated financial statements and related notes have been prepared in accordance with United StatesU.S. generally accepted accounting principles (GAAP) and amounts are stated in U.S. dollars. The financial statements and notes present the financial position of the Partnership as of December 31, 20172020 and 20162019 and the results of its operations, cash flows and changes in partners'partners’ equity for the years ended December 31, 2017, 20162020, 2019 and 2015.

2018.

(a)Basis of Presentation

The Partnership consolidates variable interestits interests in entities (VIEs) forover which it is consideredable to be the primary beneficiary as well as voting interest entities in which it has a controlling financial interest.exercise control. To the extent there are interests owned by other parties, these interests are included in non-controlling interests. The Partnership uses the equity method of accounting for its investments in entities over which it is able to exercise significant influence.

The Partnership is considered to have a variable interest in Great Lakes, which is accounted as an equity investment since the Partnership is not the primary beneficiary (Refer to Note 5 for more details).

Acquisitions by the Partnership from TransCanadaTC Energy are considered common control transactions. When businesses that will be consolidated are acquired from TransCanadaTC Energy by the Partnership, the historical financial statements are required to be recast, exceptwith the exception of net income (loss) per common unit, to include the acquired entities for all periods presented.

When the Partnership acquires an asset or an investment from TransCanada,TC Energy, which will be accounted for by the equity method, the financial information is not required to be recast and the transaction is accounted for prospectively from the date of the acquisition.

On June 1, 2017, the Partnership acquired from a subsidiary of TransCanada an additional 11.81 percent interest in PNGTS, resulting in the Partnership owning 61.71 percent in PNGTS (Refer to Note 7). As a result of the Partnership owning 61.71 percent of PNGTS, the Partnership's historical financial information was recast, except net income (loss) per common unit, to consolidate PNGTS for all the periods presented in these consolidated financial statements. Additionally, this acquisition was accounted for as transaction between entities under common control, similar to pooling of interests, whereby the assets and liabilities of PNGTS were recorded at TransCanada's carrying value.

Also, on June 1, 2017, the Partnership acquired from subsidiaries of TransCanada a 49.34 percent interest in Iroquois (Refer to Note 7). Accordingly, this transaction was accounted for as a transaction between entities under common control, similar to pooling of interest, whereby the equity investment in Iroquois was recorded at TransCanada's carrying value and was accounted for prospectively.

On January 1, 2016, the Partnership acquired a 49.9 percent interest in PNGTS (2016 PNGTS Acquisition) from a subsidiary of TransCanada. The 2016 PNGTS Acquisition was accounted for as a transaction between entities under common control, similar to a pooling of interests, whereby the equity investment in PNGTS was recorded at TransCanada's carrying value and the total excess purchase price paid was recorded as a reduction in Partners' Equity. Accordingly, the equity investment on PNGTS is being eliminated as a result of consolidating PNGTS for all periods presented. Refer to Note 7 for additional disclosure regarding the PNGTS Acquisition.

On April 1, 2015, the Partnership acquired the remaining 30 percent interest in GTN from a subsidiary of TransCanada. This acquisition resulted in being wholly-owned by the Partnership. Prior to this transaction, the remaining 30 percent interest held by a subsidiary of TransCanada was reflected as non-controlling interest in the Partnership's consolidated financial statements. The acquisitions of this already-consolidated entity was accounted as a transaction between entities under common control, similar to a pooling of interests, whereby the acquired interests were recorded at TransCanada's carrying value and the total excess purchase price paid was recorded as a reduction in Partners' Equity. Refer to Note 7 for additional disclosures regarding these acquisitions.

(b)Use of Estimates

The preparation of financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Although management believes these estimates are reasonable, actual results could differ from these estimates.

TC PipeLines, LPAnnual Report2017    F-9


(c)Government Regulation
The Partnership's subsidiaries are subject to regulation by the Federal Energy Regulatory Commission (FERC). Under FERC's regulatory accounting principles, certain assets or liabilities that result from the regulated rate-making process may be recorded that would not be recorded under GAAP for non-regulated entities. The timing of recognition of certain revenues and expenses in our regulated business may differ from that otherwise expected under GAAP to appropriately reflect the economic impact of the regulators' decisions regarding revenues and rates. The Partnership regularly evaluates the continued applicability of regulatory accounting, considering such factors as regulatory changes, the impact of competition and the ability to recover regulatory assets. At December 31, 2020 and 2019, the Partnership had an immaterial amount of regulatory assets reported as part of other current assets in the balance sheet and an immaterial amount of regulatory liabilities reported on the balance sheet as part of accounts payable and accrued liabilities. Long-term regulatory liabilities that the Partnership has collected in its current rates related to future removal costs on its transmissions and gathering facilities are included in other long-term liabilities (refer to Note 9).
(d)Cash and Cash Equivalents

The Partnership'sPartnership’s cash and cash equivalents consist of cash and highly liquid short-term investments with original maturities of three months or less and are recorded at cost, which approximates fair value.

(d)    

(e)Trade Accounts Receivable

Trade accounts receivable are recorded at the invoiced amount and do not bear interest. We review our accounts receivable regularly and record allowances for doubtful accounts using the specific identification method.

(e)    

(f)Natural gas imbalances

Natural gas imbalances occur when the actual amount of natural gas delivered to or received from a pipeline system differs from the amount of natural gas scheduled to be delivered or received. The Partnership values these imbalances due to or from
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shippers and interconnecting parties at current index prices. Imbalances are settled in kind, subject to the terms of the pipelines'pipelines’ tariff.

Imbalances due from others are reported as trade accounts receivable or accounts receivable from affiliates under the caption accounts receivable and other on the balance sheets. Imbalances owed to others are reported on the balance sheets as accounts payable and accrued liabilities and accounts payable to affiliates. The determination of the asset or liability classification is based on the net position of the customer. In addition, the Partnership classifies all imbalances as current as the Partnership expects to settle them within a year.

(f)    

(g)Inventories

Inventories primarily consist of materials and supplies and are carried at the lower of weighted average cost or market.

(g)net realizable value.

(h)Property, Plant Property and Equipment

Plant, property

Property, plant and equipment are stated at original cost. Costs of restoring the land above and around the pipeline are capitalized to pipeline facilities and depreciated over the remaining life of the related pipeline facilities. Pipeline facilities and compression equipment have an estimated useful life of 20 to 77 years and metering and other equipment ranges from 5 to 77 years. Depreciation is calculated on a straight-line composite basis over the assets' estimated useful lives. Repair and maintenance costs are expensed as incurred. Costs that are considered a betterment are capitalized.

Pipeline facilities and compression equipment have an estimated useful life of 20 to 68 years and metering and other equipment ranges from 5 to 77 years. Depreciation of our subsidiaries’ assets is based on rates approved by FERC from the pipelines’ last rate proceeding and is calculated on a straight-line composite basis over the assets’ estimated useful lives. Under the composite method, assets with similar lives and characteristics are grouped and depreciated as one asset. Amounts included in construction work in progress are not depreciated until transferred into service. During the years ended December 31, 2020, 2019 and 2018, the Partnership incurred depreciation expenses of $88 million, $78 million and $97 million, respectively. Refer to Note 7 for further details regarding our Property, plant and equipment balance.

The Partnership'sPartnership’s subsidiaries capitalize a carrying cost on funds invested in the construction of long livedlong-lived assets. This carrying cost includes a return on the investment financed by debt and equity allowance for funds used during construction (AFUDC), calculated based on the average cost of debt and equity. Capitalized carrying costs for AFUDC debt and equity are reflected as an increase in the cost of property, plant property and equipment on the balance sheets. Amounts included

Both capitalized AFUDC debt and equity amounts are reported as part of Financial Charges and Other line item in construction workthe Consolidated Statements of Operations and broken out further in progress are not amortized until transferred into service.

(h)    Note 12. Capitalized AFUDC equity amounts during the years ended December 31, 2020, 2019 and 2018 were $10 million, $2 million and $1 million, respectively. Capitalized AFUDC Debt during the year ended December 31, 2020 was $1.3 million (2019 and 2018 - less than $1 million). Refer to Note 12.

(i)Impairment of Equity Method Investments

We review our equity method investments when a significant event or change in circumstances has occurred that may have an adverse effect on the fair value of each investment. When such events or changes occur, we compare the estimated fair value to the carrying value of the related investment. We calculate the estimated fair value of an investment in an equity method investee using an income approach and market approach. The development of fair value estimates requires significant judgment including estimates of future cash flows, which is dependent on internal forecasts, estimates of the long-term rate of growth for the investee, estimates of the useful life over which cash flows will occur, and determination of weighted average cost of capital. The estimates used to calculate the fair value of an investee can change from year to year based on operating results and market conditions. Changes in these estimates and assumptions could materially affect the determination of fair value and our assessment as to whether an investment in an equity method investee has suffered an impairment.


If the estimated fair value of an investment is less than its carrying value, we are required to determine if the decline in fair value is other than temporary. This determination considers the aforementioned valuation methodologies, the length of time and the extent to which fair value has been less than carrying value, the financial condition and near-term prospects of the investee, including any specific events which may influence the operations of the investee, the intent and ability of the holder to retain its investment in the investee for a period of time sufficient to allow for any anticipated recovery in market value, and other facts and circumstances. If the fair value of an investment is less than its carrying value and the decline in value is determined to be other than temporary, we record an impairment charge.

(i)    

(j)Impairment of Long-lived Assets

The Partnership reviews long-lived assets, such as property, plant property and equipment for impairment whenever events or changes in circumstances indicate the carrying value may not be recoverable. If the total of the estimated undiscounted future cash flows is less than the carrying value of the assets, an impairment loss is recognized for the excess of the carrying value over the fair value of the assets.

F-10    

(k)Partners’ Equity
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(j)    Partners' Equity

Costs incurred in connection with the issuance of units are deducted from the proceeds received.

(k)    

(l)Revenue Recognition

Transmission

The Partnership’s revenues are generated from contractual arrangements for committed capacity and from transportation of natural gas which are treated as a bundled performance obligation. Revenues earned from firm contracted capacity arrangements are recognized inratably over the period in whichterm of the contract regardless of the amount of natural gas that is transported. Transportation revenues for interruptible or volumetric-based services are recognized when the service is provided. Whenperformed. The Partnership utilizes the practical expedient of recognizing revenue as invoiced. Revenues are invoiced and paid on a rate casemonthly basis. The Partnership’s pipeline systems do not take ownership of the natural gas that is pending finaltransported for customers. Revenues from contracts with customers are recognized net of any taxes collected from customers, which are subsequently remitted to governmental authorities.
The Partnership's pipeline systems are subject to FERC approval,regulations and, as a result, a portion of the revenuerevenues collected ismay be subject to possible refund. As of December 31, 2017,refund if invoiced during an interim period when a rate proceeding is ongoing. Allowances for these potential refunds are recognized using management’s best estimate based on the Partnership has not recognized any transmission revenue that is subject to possible refund.

For the years ended December 31, 2014facts and in January 2015, as required by FERC, PNGTS was charging customers rates applied for in its 2008 and 2010 rate cases. Due to the uncertainty in the outcome of its two outstanding rate cases, PNGTS was only recognizing revenue up to the amountcircumstances of the interim FERC approved rates. The difference between these amounts wasproceeding. Any allowances that are recognized during the proceeding process are refunded or retained, as a provision (liability) for rate refund in the consolidated balance sheet. On February 19, 2015, FERC approved PNGTS' final rates and PNGTS was required to refund the customers within sixty days of the issuance of the final rates, including interestapplicable, at the quarterly average prime interest rate as prescribed by FERC. Total refunds accumulatedtime a regulatory decision becomes final. Refer to $114.3 million, including $8.0 million of interest, and were paid to customers on April 15, 2015.

(l)    Note 6 for detailed disclosures regarding the Partnership’s revenues.

(m)Debt Issuance Costs

Costs related to the issuance of debt are deferred and amortized using the effective interest rate method over the term of the related debt. Debt issuancesConsistent with debt discount, debt issuance costs are presented in the balance sheet as a direct deduction from the carrying amount of debt liabilities, consistent with debt discount and premiums.liabilities. The amortization of debt issuance costs is reported as interest expense.

(m)    

(n)Income Taxes

Federal

U.S. federal and certain state income taxes are the responsibility of the partners and are not reflected in these consolidated financial statements. The tax effect of the Partnership's activities accrues to its partners. The Partnership'sPartnership’s taxable income or loss, which may vary substantially from the net income or loss reported in the consolidatedConsolidated statement of income,operations, is includable in the U.S. federal income tax returns of each partner. The aggregate difference in the basis of the Partnership'sPartnership’s net assets for financial and income tax purposes cannot be readily determined because all information regarding each partner'spartner’s tax attributes related to the partnership is not available.

In instances where the Partnership is subject to state income taxes, the asset – liabilityasset-liability method is used to account for taxes. This method requires the recognition of deferred tax assets and liabilities for future tax consequences attributable to the differences between the financial statement carrying amount of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are classified as non-current on our balance sheet.

(n)    

State Income Taxes in Oregon

Beginning in 2020, the Partnership became subject to a corporate activity tax in Oregon which is measured on the commercial activity of a business and levied at the partnership level. The tax amounted to $0.6 million for the year ended December 31, 2020 and was included in current income tax expense.
State Income Taxes in New Hampshire
PNGTS is subject to the business profits tax (BPT) levied at the partnership level by the state of New Hampshire (NH). As a result of the BPT, PNGTS recognizes deferred taxes related to temporary differences between the financial statement carrying amount of existing assets and liabilities and their respective tax bases. The deferred taxes at December 31, 2020, 2019 and 2018 relate primarily to utility plant. The NH BPT effective tax rate was 3.0 percent for the year ended December 31, 2020 (2019 – 2.6 percent, 2018 – 3.5 percent) and was applied to PNGTS’ taxable income. During the year ended December 31, 2020 and 2018, PNGTS recorded state income tax expense amounting to $5 million and $1 million, respectively. In 2019, PNGTS recognized a state income tax benefit of $1 million.
(o)Acquisitions and Goodwill

The Partnership accounts for business acquisitions from third parties using the acquisition method of accounting and, accordingly, the assets and liabilities of the acquired entities are recorded at their estimated fair values at the date of acquisition. The excess of the purchase price over the fair value of net assets acquired is attributed to goodwill.
Goodwill is not amortized and is tested for impairment on an annual basis for impairment or more frequently if any indicators of impairment are evident. The Partnership can initially assessesassess qualitative factors to determine whether events or changes in circumstances indicate that the goodwill might be impaired. The factors the Partnership considers include, but are not limited to, macroeconomic conditions, industry and market considerations, cost factors, historical and forecasted financial results, and events specific to that reporting unit. If the Partnership doesconcludes there is not concludea greater than 50 percent likelihood that it is more likely than not thatthe fair value of the reporting unit is greater than its carrying value, the first stepPartnership will then perform the quantitative goodwill impairment test. The Partnership can
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also elect to proceed directly to the two-stepquantitative goodwill impairment test for any of its reporting units. If the quantitative goodwill impairment test is performed, by comparingthe Partnership compares the fair value of the reporting unit to its bookcarrying value, which includesincluding its goodwill. If the fair value is less than book value, an impairment is indicated and a second step is performed to measure the amount of the impairment. In the second step, the implied fair value of goodwill is calculated by deducting the recognized amounts of all tangible and intangible net assets of the reporting unit from the fair value determined in the initial assessment. If the carrying value of a reporting unit including its goodwill exceeds its fair value, goodwill impairment is measured at the calculated impliedamount by which the reporting unit’s carrying value exceeds its fair value.
We calculate the estimated fair value of the reporting unit using an income approach and market approach. The development of fair value estimates requires significant judgment including estimates of future cash flows, which is dependent on internal forecasts, estimates of the long-term rate of growth for the reporting unit, estimates of the useful life over which cash flows will occur, and a determination of weighted average cost of capital. The estimates used to calculate the fair value of the reporting unit can change from year to year based on operating results and market conditions. Changes in these estimates and assumptions could materially affect the determination of fair value and our assessment as to whether the goodwill in the reporting unit has suffered an impairment charge is recorded.

At December 31, 2017 and 2016, we had $130 million of goodwill recorded on our consolidated balance sheet related to the North Baja ($48 million) and Tuscarora ($82 million) acquisitions. No impairment of goodwill existed at December 31, 2017.

impairment.

The Partnership accounts for business acquisitions between itself and TransCanada,affiliates under TC Energy, also known as "dropdowns",“dropdowns,” as transactions between entities under common control. Using this approach, the assets and liabilities of the acquired entities are recorded at TransCanada'sTC Energy’s carrying value. In the event recasting is required, the Partnership'sPartnership’s historical financial information will be recast, exceptwith the exception of net income (loss) per common unit, to include the acquired entities for all periods presented. If the fair market value paid for the acquired entities is greater than the recorded net assets of the acquired entities, the excess purchase price paid is recorded as a reduction in Partners' Equity.Partners’ equity. Similarly, if the fair market value paid for the acquired entities is less than the recorded net assets of the acquired entities, the excess of assets acquired is recorded as an increase in Partners' Equity.

TC PipeLines, LPAnnual Report2017    F-11


(o)    Partners’ equity.

(p)Fair Value Measurements

For cash and cash equivalents, receivables, accounts payable, certain accrued expenses and short-term debt, the carrying amount approximates fair value due to the short maturities of these instruments. For long-term debt instruments and the interest rate swap agreements, fair value is estimated based upon market values (if applicable) or on the current interest rates available to us for debt with similar terms and remaining maturities. Considerable judgmentJudgment is required in developing these estimates.

(p)    

(q)Derivative Financial Instruments and Hedging Activities

The Partnership recognizes all derivative instruments as either assets or liabilities in the balance sheet at their respective fair values. For derivatives designated in hedging relationships, changes in the fair value are either offset through earnings against the change in fair value of the hedged item attributable to the risk being hedged or recognized in accumulated other comprehensive income, to the extent the derivative is effective at offsetting the changes in cash flows being hedged until the hedged item affects earnings.

The Partnership only enters into derivative contracts that it intends to designate as a hedge of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge). For all hedging relationships, the Partnership formally documents the hedging relationship and its risk management objective and strategy for undertaking the hedge, the hedging instrument, the hedged transaction, the nature of the risk being hedged, how the hedging instrument's effectiveness in offsetting the hedged risk will be assessed prospectively and retrospectively, and a description of the method used to measure ineffectiveness. The Partnership also formally assesses, both at the inception of the hedging relationship and on an ongoing basis, whether the derivatives that are used in hedging relationships are highly effective in offsetting changes in cash flows of hedged transactions. For derivative instruments that are designated and qualify as part ofIn a cash flow hedging relationship, the effective portionchange in the fair value of the gain or loss on thehedging derivative is reported as a component of other comprehensive income and reclassified into earnings as part of “financial charges and other” line in the Consolidated statement of operations in the same period or periods during which the hedged transaction affects earnings. Gains and losses onearnings or is reclassified immediately to net income when the derivative representing either hedge ineffectivenesshedged item is sold or hedge components excluded from the assessment of effectiveness are recognized in current earnings.

The Partnership discontinues hedge accounting prospectivelyterminated early, or when it determinesbecomes probable that the derivative is no longer effective in offsetting cash flows attributable to the hedged risk, the derivative expires or is sold, terminated, or exercised, the cash flow hedge is de-designated because a forecasted transaction is not probable of occurring, or management determines to remove the designation of the cash flow hedge.

In all situations in which hedge accounting is discontinued and the derivative remains outstanding, the Partnership continues to carry the derivative at its fair value on the balance sheet and recognizes any subsequent changes in its fair value in earnings. When it is probable that a forecastedanticipated transaction will not occur,occur.

In some instances, the Partnership discontinuesderivatives do not meet the specific criteria for hedge accounting and recognizes immediatelytreatment. In these instances, the changes in earnings gains and losses that were accumulatedfair value are recorded in other comprehensivenet income related toin the hedging relationship.

(q)    period of change.

(r)Asset Retirement Obligation

The Partnership recognizes the fair value of a liability for asset retirement obligations in the period in which it is incurred, when a legal obligation exists, and a reasonable estimate of fair value can be made. The fair value is added to the carrying amount of the associated asset and the liability is accreted through charges to operating expenses.

The Partnership has determined it has legal obligations associated with its natural gas pipelines and related transmission facilities. The obligations relate primarily to purging and sealing the pipelines if they are abandoned. The Partnership is also required to operate and maintain its natural gas pipeline system and intends to do so as long as supply and demand for natural gas exists, which the Partnership expects for the foreseeable future. Therefore, the Partnership believes its natural gas pipeline systemsystem’s assets have indeterminate lives and, accordingly, has recorded no0 asset retirement obligation as of December 31, 20172020 and 2016.

(r)    Government Regulation

2019.

(s)Contingencies
The Partnership's subsidiariesPartnership and its pipeline systems are subject to regulation by FERC. Under regulatoryvarious legal proceedings in the ordinary course of business. Our accounting principles, certain assetsfor contingencies covers a variety of business activities, including contingencies for legal and environmental liabilities. The Partnership accrues for these contingencies when the assessments indicate it is probable that a liability has been incurred or liabilities that result from the regulated ratemaking process may be recorded that wouldan asset will not be recorded under GAAP for non-regulated entities. The timingrecovered, and an amount can be reasonably estimated in accordance with ASC 450, Contingencies. We
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Table of recognitionContents
base these estimates on currently available facts and the estimates of certain revenues and expenses in our regulated businessthe ultimate outcome or resolution. Actual results may differ from estimates resulting in an impact, positive or negative, on earnings and cash flow. Contingencies that otherwise expected under GAAP to appropriately reflect the economic impact of the regulators' decisions regarding revenues and rates. The Partnership regularly evaluates the continued applicability of regulatory accounting, considering such factors as regulatory changes, the impact of competition, and the ability to recover regulatory assets. might result in a gain are not accrued in our consolidated financial statements.
At December 31, 2017,2020, the Partnership had regulatory assets amounting to nil reported as partis not aware of other current assets inany contingent liabilities that would have a material adverse effect on the balance sheet representing volumetric fuel tracker assets that are settled with in-kind exchanges with customers continually (2016 – $1 million). Regulatory liabilities are included in other long-term liabilities (refer to Note 9). AFUDC is capitalized and included in plant, property and equipment.

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Partnership’s financial condition, results of operations or cash flows.

NOTE 3 ACCOUNTING PRONOUNCEMENTS

Changes in Accounting Policies effective January 1, 2017

Inventory

2020


Measurement of credit losses on financial instruments

In July 2015, the FASB issued new guidance on simplifying the measurement of inventory. The new guidance specifies that an entity should measure inventory within the scope of this update at the lower of cost and net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. This new guidance was effective January 1, 2017, was applied prospectively and did not have a material impact on the Partnership's consolidated balance sheet.

Equity method and joint ventures

In MarchJune 2016, the FASBFinancial Accounting Standards Board (FASB) issued new guidance that simplifies the transition to equity method accounting.changes how entities measure credit losses for most financial assets and certain other financial instruments that are not measured at fair value through net income (loss). The new guidance eliminatesamends the requirement to retroactively applyimpairment model of financial instruments basing it on expected losses rather than incurred losses. These expected credit losses will be recognized as an allowance rather than as a direct write down of the equity method of accounting when an increase in ownership interest in an investment qualifies for equity method accounting.amortized cost basis. The new guidance isbecame effective January 1, 20172020 and was applied prospectively.using a modified retrospective approach. The applicationadoption of this new guidance did not have a material impact on the Partnership'sPartnership’s consolidated financial statements.


Consolidation


In October 2016,2018, the FASB issued new guidance on consolidation relatingfor determining whether fees paid to decision makers and service providers are variable interests for indirect interests held through related parties that are under common control. TheThis new guidance amends the consolidation requirements such that if a decision maker is required to evaluate whether it is the primary beneficiary of a variable interest entity (VIE), it will need to consider only its proportionate indirect interest in the VIE held through a common control party. The guidance wasbecame effective January 1, 2017,2020, and was applied retrospectively andon a retrospective basis. The adoption of this new guidance did not resulthave a material impact on the Partnership’s consolidated financial statements.

Reference rate reform

In March 2020, in any changeresponse to our consolidation conclusions.

Future accounting changes

Revenuethe expected cessation of the London Interbank Offered Rate (LIBOR) from contracts with customers

In 2014,late 2021 to mid-2023, the FASB issued new optional guidance on revenue from contracts with customers.that eases the potential burden of accounting for reference rate reform. The new guidance requiresprovides optional expedients for contracts and hedging relationships that an entity recognize revenue in accordance with a prescribed model. This model is used to depict the transfer of promised goods or services to customers in an amount that reflects the total consideration to which it expects to be entitled during the termare affected by reference rate reform, if certain criteria are met. Each of the contract in exchange for those goods or services. The new guidance also requires additional disclosures about the nature, amount, timing and uncertainty of revenue and the related cash flows. The Partnership will adopt the new standard on the effective dateexpedients can be applied as of January 1, 2018. There are two methods in which the new standard can be adopted: (1) a full retrospective approach with restatement of all prior periods presented, or (2) a modified retrospective approach with a cumulative-effect adjustment2020 through December 31, 2022. For eligible hedging relationships existing as of the date of adoption. The Partnership will adopt the guidance using the modified retrospective approach with the cumulative-effect of the adjustment recognized at the date of adoption, subject to allowableJanuary 1, 2020 and elected practical expedients.

Theprospectively, the Partnership has identified all existing customer contracts that are withinapplied the scope of the new guidance. The Partnership has completed its analysis and has not identified any material differences in the amount and timing of revenue recognition as a result of implementing the new guidance. The Partnership will not require a cumulative-effect adjustmentoptional expedient allowing an entity to opening partners' equity on January 1, 2018.

Although consolidated revenues will not be materially impacted by the new guidance, the Partnership will be required to add significant disclosures based on the prescribed requirements. These new disclosures will include information regarding the significant judgments used in evaluating when and how revenue is recognized and information related to contract assets and deferred revenues. In addition, the new guidance requiresassume that the Partnership's revenue recognition policy disclosure includes additional detail regarding the various performance obligations and the nature, amount, timing and estimateshedged forecasted transaction in a cash flow hedge is probable of revenue and cash flows generated from contracts with customers. The Partnership has developed draft disclosures required in the first quarter 2018 with a particular focus on the scope of contracts subject to disclosure of future revenues from remaining performance obligations. The Partnership has addressed system and process changes necessary to compile the information to meet the recognition and disclosure requirements of the new guidance.

Leases

In February 2016, the FASB issued new guidance on the accounting for leases. The new guidance amends the definition of a lease requiring the customer to have both (1) the right to obtain substantially all of the economic benefits from the use of the asset and (2) the right to direct the use of the asset in order for the arrangement to qualify as a lease. The new guidance also establishes a right-of-use (ROU) model that requires a lessee to recognize a ROU asset and corresponding lease liability on the balance sheet for all leases with a term longer than

TC PipeLines, LPAnnual Report2017    F-13



12 months. Leases will be classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The new guidance does not make extensive changes to lessor accounting.

The new guidance is effective on January 1, 2019, with early adoption permitted. A modified retrospective transition approach is required for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available. Theoccurring.The Partnership is continuing to identify and analyze existing lease agreements to determine the effect of adoption of the new guidancereference rate reform on its consolidated financial statements.statements The Partnership is also addressing systemwill continue to evaluate the timing and process changes necessarypotential impact of adoption of other optional expedients when deemed necessary.



NOTE 4 GOODWILL
Under U.S. GAAP, we evaluate our goodwill related to compileTuscarora and North Baja for impairment at least annually or more frequently if indicators of impairment are evident.

In 2018, our analysis resulted in the information to meet the recognition and disclosure requirements of the new guidance. The Partnership continues to monitor and analyze additional guidance and clarification provided by FASB.

Goodwill Impairment

In January 2017, the FASB issued new guidance on simplifying the test for goodwill impairment by eliminating the requirement to calculate the impliedestimated fair value of Tuscarora not exceeding its carrying value, including goodwill that primarily resulted from the 2019 Tuscarora Settlement as part of the 2018 FERC Actions. As a result, we recorded a goodwill impairment charge amounting to measure the impairment charge. Instead, entities will record$59 million against Tuscarora’s goodwill balance of $82 million.


In 2019, based on our analysis of Tuscarora and North Baja’s current market conditions, we believed there was a greater than 50 percent likelihood that Tuscarora and North Baja’s estimated fair value exceeded their carrying value. As a result, at December 31, 2019, we did not identify an impairment charge based on the excess$71 million of a reporting unit's carrying amount over its fair value. This new guidance is effective January 1, 2020 and will be applied prospectively, however, early adoption is permitted.

Hedge Accounting

In August 2017, the FASB issued new guidance on hedge accounting, making more financial and nonfinancial hedging strategies eligible for hedge accounting. The new guidance amends the presentation requirements relatinggoodwill related to the change in fair value ofTuscarora ($23 million) and North Baja ($48 million) reporting units.


On a derivative and additional disclosure requirements include cumulativequarterly basis adjustments for fair value hedgesduring 2020, we evaluated changes within our business and the effect of hedging on individual statement of income line items.external environment including considerations regarding whether such changes are permanent, to determine whether a triggering event had occurred. This new guidance is effective January 1, 2019 with early adoption permitted. The Partnership has elected to apply this guidance effective January 1, 2018. The Partnership has completed its analysis and does not expectincluded the application of this guidance to have a material impact on its consolidated financial statements.

NOTE 4    THE 2017 TAX ACT

On December 22, 2017, the President of the United States signed into law the 2017 Tax Act. This legislation provides for major changes to U.S. corporate federal tax law. As mentioned in Note 2, we are a non-taxable limited partnership, and income taxes owed as a result of our earnings are the responsibility of our partners, therefore no amounts have been recorded in the Partnership's financial statements as a result of the 2017 Tax Act.

Our pipeline systems are regulated by the FERC, which approves the systems' rates on a cost-of-service basis and provides for a recovery of our ultimate taxable owners' income tax expense and related balance sheet accounts as components of the maximum recourse rates that may be charged to customers. As a non-taxable entity, the Partnership does not recognize federal income tax expense nor has it established the related federal deferred income tax assets or liabilities. Income tax related expenses, benefits, assets, and liabilities attributable to regulated operations are the responsibility of the ultimate taxable owners of the Partnership and any adjustment to income tax accounts following the 2017 Tax Act must be evaluated by those owners.

Any changes to the maximum recourse rates charged by our pipeline systems following the 2017 Tax Act will be reflected as those rates are revised through future rate proceedings individually unless superseded through other possible future action by the FERC. The Partnership cannot predict the ultimate impact of the 2017 Tax Act on future revenues of our pipeline systems.

At December 31, 2017, the Partnership considers itsquarterly assessment of the impact of COVID-19 on our North Baja and Tuscarora reporting units. Through our quarterly analysis, no triggering events were identified.


The following factors were considered as part of our annual qualitative analysis specific to the 2017 Tax ActPartnership's Tuscarora and North Baja reporting units:
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Table of Contents



we evaluated the multiples and discount rate assumptions within the current economic environment and compared to be its best interpretationthe last quantitative model. The multiples and discount rates identified for the current year, used in our qualitative model, are reflective of available guidance. Should additional guidancethe long-term outlook for Tuscarora and North Baja, in line with their underlying asset lives;

at least 90 percent of Tuscarora's and North Baja's revenue is tied to long-term take-or-pay, fixed-price contracts which have a low correlation to short-term changes in demand;

Tuscarora and North Baja have not experienced any material customer defaults to date and hold collateral, as appropriate, in support of their contracts;

Tuscarora's expansion project, Tuscarora XPress and North Baja's expansion project, North Baja XPress, are materially on track, and we do not anticipate any significant changes in outlook or delay or inability to proceed due to financing requirements; and

Tuscarora and North Baja's businesses are broadly considered essential in the United States given the important role their infrastructures play in delivering energy to the market areas they serve.

Based on our qualitative analysis of Tuscarora and North Baja’s current market conditions we believe there is a greater than 50 percent likelihood that Tuscarora and North Baja’s estimated fair value exceeded their carrying value. As a result, at December 31, 2020, we have not identified an impairment on the impact$71 million of goodwill related to the 2017 Tax ActTuscarora ($23 million) and North Baja ($48 million) acquisitions. Adverse changes to our key considerations could, however, result in future impairments on non-taxable partnerships be provided by regulatory, tax and accounting authorities or other sources in the future, the Partnership will review the approach used and adjust as appropriate.

our goodwill.

NOTE 5 EQUITY INVESTMENTS

The Partnership has equity interests in Northern Border, Great Lakes and effective June 1, 2017, Iroquois. The pipeline systems owned by these entities are regulated by FERC. The pipeline systems of Northern Border and Great Lakes are operated by subsidiaries of TransCanada.TC Energy. The Iroquois pipeline system is operated by Iroquois Pipeline Operating Company, a wholly owned subsidiary of Iroquois. The Partnership uses the equity method of accounting for its interests in its equity investees. The Partnership's equity investments are held through our ILPs that are considered to be variable interest entities (VIEs). Refer to Note 23, Variable Interest Entities.

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Equity Earnings(b)

 
Equity Investments

 
  
 
Year ended December 31

 
December 31

 
 
Ownership
Interest at
December 31,
2017

(millions of dollars)
 
2017

 
2016(c)

 
2015

 
2017

 
2016(c)

 

Northern Border(a) 50.00% 67 69 66 512 444 
Great Lakes 46.45% 31 28 31 479 474 
Iroquois 49.34% 26   222  

    124 97 97 1,213 918 

Ownership
Interest at
Equity Earnings (b)
Equity Investments
December 31,
2020
Year ended December 31December 31
(millions of dollars)20202019201820202019
Northern Border(a)
50.00 %76 69 68 407 422 
Great Lakes46.45 %56 51 59 509 491 
Iroquois49.34 %38 40 46 154 185 
170 160 173 1,070 1,098 
(a)
Equity earnings from Northern Border is net of the 12-year amortization of a $10 million transaction fee paid to the operator of Northern Border at the time of the Partnership'sPartnership’s acquisition of an additional 20 percent in April 2006.

The fee was fully amortized in May 2018.
(b)
Equity Earnings represents our share in investee'san investee’s earnings and does not include any impairment charge on the equity method investment recorded as a reduction of carrying value of these investments. Accordingly, no0 impairment charge was recorded by the Partnership on its equity investees for all the periods presented here excepthere.
Impairment considerations
As noted under Note 2 - Significant accounting policies, our equity investments in Northern Border, Great Lakes and Iroquois are evaluated whenever events or changes in circumstances indicate that the $199 millioncarrying amounts may not be recoverable. We performed a qualitative analysis to determine if there was a non-temporary decline in our equity investments' fair value and no triggers were identified. As a result, we continue to believe no impairment recognized in 2015exists on our investmentequity investments. There is a risk that adverse changes in Great Lakes as discussed below.

(c)
Recastour analysis could result in additional quantitative steps to eliminateevaluate our equity earnings from PNGTS and consolidate PNGTS (Refer to Notes 2 and 7).

method investments.

Distributions from Equity Investments

As a result of adoption of FASB ASU 2016-15,Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments, the Partnership changed its method of accounting for the classification of distributions received from equity investments from cumulative earnings approach to nature of distributions approach effective January 1, 2014, as it is more representative of the nature of the underlying activities of the investees that generated the distributions. As a result, distributions received from equity method investees in 2015, amounting to $25 million, have been reclassified from investing activities to cash generated from operations in the consolidated statement of cash flows.

Distributions received from equity investments for the year ended December 31, 20172020 were $145$225 million (2016 – $153(2019 - $258 million; 2015 – $1192018 - $198 million) of which $5$29 million (2016(2019 - $58 million and 2015 – none)2018 - $10 million) was considered a return of capital and is included in Investing activities in the Partnership'sPartnership’s consolidated statement of cash flows. The return of capital was related to our investment in Northern Border and Iroquois (see further discussion below).

Northern Border

The Partnership, through its interest in

TC PipeLines, Intermediate Limited Partnership owns a 50 percent general partner interest in Northern Border. The other 50 percent partnership interest in Northern Border is held by ONEOK Partners, L.P., a publicly traded limited partnership.TC PipeLines Intermediate Limited Partnership, as oneLP Annual Report 2020F-15

Table of Contents
During the general partners, may be exposed to the commitments and contingencies of Northern Border. The Partnership holds a 98.9899 percent limited partnership interest in TC PipeLines Intermediate Limited Partnership.

On September 1, 2017,year ended December 31, 2020, the Partnership made an equity contribution toreceived distributions from Northern Border amounting to $91 million (2019 - $144 million; 2018 – $83 million. This amount representsmillion) The $144 million received in 2019 included the Partnership's 50 percent share of a $166 million capital contribution request fromthe Northern Border to reduce the outstanding balance of its$100 million distribution in June 2019. The $100 million distribution was 100 percent financed by borrowing on Northern Border's $200 million revolving credit facility to increase its available borrowing capacity.

facility. The $50 million of cash the Partnership received did not represent a distribution of operating cash flow during the period and, therefore, it was reported as a return of investment in the Partnership's consolidated statement of cash flows.

The Partnership recorded no0 undistributed earnings from Northern Border for the years ended December 31, 2017, 20162020, 2019 and 2015.2018. At December 31, 20172020 the Partnership had a $115 million (December 31, 2016 – $1162019 - $115 million) difference between the carrying value of Northern Border and the underlying equity in the net assets primarily resulting from the recognition and inclusion of goodwill in the Partnership'sPartnership’s investment in Northern Border relating to the Partnership'sPartnership’s April 2006 acquisition of an additional 20 percent general partnership interest in Northern Border.

Northern Border's 2013 settlement agreement required Northern Border to file for new rates no later than January 1, 2018. On December 4, 2017, Northern Border filed a rate settlement with FERC which precluded the need to file a general rate case by January 1, 2018. The 2017 Northern Border Settlement, which was approved by FERC on February 23, 2018, provides for tiered rate reductions beginning January 1, 2018, with no change to the underlying rate design. The 2017 Northern Border Settlement does not contain a moratorium provision and, unless superseded by a subsequent rate case or settlement, recourse rates in effect at December 31, 2017, will decrease by 5.0% on January 1, 2018; by an additional 5.50% on April 1, 2018; and by an additional 2.0% beginning January 1, 2020 through December 31, 2023, when Northern Border will be required to establish new rates. This equates to an overall rate reduction of 12.5% by January 1, 2020 from the recourse rates in effect at December 31, 2017.

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The 2017 Northern Border Settlement will provide Northern Border with rate stability over the longer term. We do not believe that the rate reduction as described above will have a material impact on the Partnership's results and, therefore, we do not believe the settlement outcome has negatively impacted the underlying value of our investment in Northern Border. The overall long-term market fundamentals of Northern Border continue to be positive due to its strategic footprint. Northern Border remains a key competitive pipeline and continues to operate at full capacity connecting major supply basins with communities in the Midwestern U.S. Accordingly, no impairment has been identified in our investment in Northern Border.

The summarized financial information provided to us by Northern Border is as follows:

December 31 (millions of dollars) 
2017
 
2016
  

Assets      
Cash and cash equivalents 14 14  
Other current assets 36 36  
Plant, property and equipment, net 1,063 1,089  
Other assets 14 14  

  1,127 1,153  

Liabilities and Partners' Equity      
Current liabilities 38 38  
Deferred credits and other 31 28  
Long-term debt, net(a) 264 430  
Partners' equity      
 Partners' capital 795 659  
 Accumulated other comprehensive loss (1)(2) 

  1,127 1,153  

Year ended December 31 (millions of dollars) 
2017
 
2016
 
2015
  

Transmission revenues 291 292 286  
Operating expenses (78)(72)(70) 
Depreciation (59)(59)(60) 
Financial charges and other (18)(21)(22) 

Net income 136 140 134  

December 31 (millions of dollars)
20202019
Assets
Cash and cash equivalents31 21 
Other current assets38 37 
Property, plant and equipment, net977 989 
Other assets12 12 
1,058 1,059 
Liabilities and Partners’ Equity
Current liabilities52 42 
Deferred credits and other42 39 
Long-term debt, net (a)
380 364 
Partners’ equity
Partners’ capital584 615 
Accumulated other comprehensive loss0 (1)
1,058 1,059 
Year ended December 31 (millions of dollars)
202020192018
Transmission revenues308 300 289 
Operating expenses(77)(82)(78)
Depreciation(62)(62)(60)
Financial charges and other(18)(18)(15)
Net income151 138 136 
(a)
NoIncludes current maturities of $250 million as of December 31, 2017 or 2016.

2020 for Northern Border's 7.50% Senior Notes (December 31, 2019 - NaN), net of unamortized debt issuance costs and debt discounts. At December 31, 2020, Northern Border was in compliance with all of its financial covenants.

Great Lakes,

a variable interest entity


The Partnership through its interest in TC GL Intermediate Limited Partnership, ownsis considered to have a 46.45 percent general partnervariable interest in Great Lakes. TransCanada ownsLakes, which is accounted for as an equity investment as we are not its primary beneficiary. A variable interest entity is a legal entity that either does not have sufficient equity at risk to finance its activities without additional subordinated financial support, is structured such that equity investors lack the other 53.55 percent partnership interest. TC GL Intermediate Limited Partnership, as oneability to make significant decisions relating to the entity’s operations through voting rights or do not substantively participate in the gains or losses of the general partners, may be exposedentity.
During the year ended December 31, 2020, the Partnership received distributions from Great Lakes amounting to $48 million (2019 - $59 million; 2018 - $58 million), all of which were reported as a return on investment in the commitments and contingenciesPartnership's consolidated statement of cash flows.
During the year ended December 31, 2020, the Partnership made equity contributions to Great Lakes. The Partnership holds a 98.9899 percent limited partnership interest in TC GL Intermediate Limited Partnership.

Lakes amounting to $10 million representing cash calls from Great Lakes to make scheduled debt payments (2019 - $10 million 2018 - $9 million)

The Partnership recorded no0 undistributed earnings from Great Lakes for the years ended December 31, 2017, 2016,2020, 2019, and 2015.

The Partnership made2018.

At December 31, 2020, the equity contributionsmethod goodwill related to Great Lakes amounted to $260 million (December 31, 2019 - $260 million). The equity method goodwill relates to the Partnership’s February 2007 acquisition of $4 million and $5 million in the first and fourth quarter of 2017, respectively. These amounts represent the Partnership'sa 46.45 percent sharegeneral partner
F-16     TC PipeLines, LP Annual Report 2020

Table of a $9 million and $10 million cash call fromContents
interest in Great Lakes to make scheduled debt repayments.

During the fourth quarter of 2015, we recorded an impairment charge of $199 million on our investment in Great Lakes. The impairment charge was the result of our determination that our investment in Great Lakes' long-term value had been adversely impacted by the changing natural gas flows in its market region and that other strategic alternatives to increase its utilization or revenue were no longer feasible. The impairment charge reducedis the difference between the carrying value of our investment in Great Lakes and the underlying equity in theGreat Lakes’ net assets, to $260 million and the difference represented the equity method goodwill remaining in our investment in Great Lakes relating to the Partnership's February 2007 acquisition of a 46.45 percent general partner interest in Great Lakes.

On October 30, 2017, Great Lakes filed a rate settlement with FERC to satisfy its obligations from its 2013 rate settlement for new rates to be in effect by January 1, 2018. The 2017 Great Lakes Settlement does not contain a moratorium provision and Great Lakes will be required to file for new rates no later than March 31, 2022, with new rates to be effective October 1, 2022. The 2017 Great Lakes Settlement, which was approved by FERC on February 22, 2018, decreased Great Lakes' maximum transportation rates by 27 percent effective October 1, 2017. At December 31, 2017, the estimation of fair value on the remaining equity investment in Great Lakes was completed and we concluded the fair value of our investment in Great Lakes has not materially changed from 2015.

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The assumptions we used in the analysis related to the estimated fair value of our remaining equity investment in Great Lakes included the reduction in Great Lakes' rates effective October 1, 2017. The reduction in rates was offset by expected cash flows from the long-term transportation contract with the TransCanada other revenue opportunities on the system and the settlement's elimination of the revenue sharing mechanism with its customers. Although evolving market conditions and other factors relevant to Great Lakes' long term financial performance have remained positive, there is a risk that reductions in future cash flow forecasts or adverse changes in other key assumptions could result in an additional future impairment of the carrying value of our investment in Great Lakes.

Our key assumptions could be negatively impacted by near and long-term conditions including:

future regulatory rate action or settlement,

valuation of Great lakes in future transactions,

changes in customer demand at Great Lakes for pipeline capacity and services,

changes in North American natural gas production in the major producing basins,

changes in natural gas prices and natural gas storage market conditions,

discount rates and multiples used, and

changes in other long-term strategic objectives.

assets.

The summarized financial information provided to us by Great Lakes is as follows:

December 31 (millions of dollars) 
2017
 
2016
 

Assets     
Current assets 107 66 
Plant, property and equipment, net 701 714 

  808 780 


Liabilities and Partners' Equity

 

 

 

 

 
Current liabilities 75 40 
Long-term debt, net(a) 259 278 
Other long term liabilities 1  
Partners' equity 473 462 

  808 780 

Year ended December 31 (millions of dollars) 
2017
 
2016
 
2015
  

Transmission revenues 181 179 177  
Operating expenses (66)(69)(59) 
Depreciation (29)(28)(28) 
Financial charges and other (20)(21)(23) 

Net income 66 61 67  

December 31 (millions of dollars)
20202019
Assets
Current assets66 72 
Property, plant and equipment, net716 685 
782 757 
Liabilities and Partners’ Equity
Current liabilities38 33 
Long-term debt, net (a)
198 219 
Other long-term liabilities9 
Partners’ equity537 499 
782 757 
Year ended December 31 (millions of dollars)
202020192018
Transmission revenues239 238 246 
Operating expenses(70)(79)(68)
Depreciation(33)(32)(32)
Financial charges and other(15)(16)(18)
Net income121 111 128 
(a)
Includes current maturities of $19$31 million as of December 31, 20172020 (December 31, 2016 – $192019 - $21 million).

Iroquois

On June 1, 2017, the Partnership, through its interest in TC PipeLines Intermediate Limited Partnership acquired a 49.34 percent interest in Iroquois.

For the year ended December 31, 2017, The2020, the Partnership received distributions from Iroquois amounting to $27$86 million (2019 - $55 million: 2018 - $56 million) which includes the Partnership'sPartnership’s 49.34 percent share of the Iroquois unrestricted cash distribution as part of its 2017 acquisition agreement with Iroquois amounting to approximately $5 million (Refer to Note 7)(2019 - $8 million) . This amount is

Also included in the $86 million distribution was the Partnership's receipt of (a) a $24 million one-time, non-recurring distribution from Iroquois, representing our 49.34 percent of the reimbursement proceeds received by Iroquois from a terminated project that was guaranteed by the customer and (b) an additional $4 million distribution representing our 49.34 percent of the excess cash generated by Iroquois' operating activities in 2020.

The 2020 unrestricted cash of $5 million (2019 - $8 million) and the $24 million non-recurring distributions do not represent a distribution of Iroquois’ cash from operations during the period and therefore were reported as distributions received asa return of investment in the Partnership'sPartnership’s consolidated statement of cash flows.

The Partnership made an equity contribution to Iroquois of $2 million and $4 million in December 2020 and August 2019, respectively. This amount represents the Partnership’s 49.34 percent share of a cash call from Iroquois to cover costs of regulatory approvals related to their capital project.
The Partnership recorded no0 undistributed earnings for the period from June 1, 2017, acquisition date throughyears ended December 31, 2017.2020, 2019 and 2018. At December 31, 2017,2020 and 2019, the Partnership had a $41$39 million and $40 million difference, respectively, between the carrying value of Iroquois and the underlying equity in the net assets primarily from TransCanada'sTC Energy’s carrying value and is due to theirthe fair value assessment of Iroquois'Iroquois’ assets at the time of its acquisition of interests from third parties (refer to Note 2-Acquisitions2 - Acquisitions and Goodwill for our accounting policy on acquisitions from TransCanada)

TC PipeLines, LPAnnual Report2017    F-17


Energy).

Distribution receivable from Iroquois
Iroquois declared its third quarter 2019 distribution of $28 million on November 1, 2019, and the Partnership received its 49.34 percent share or $14 million on January 6, 2020.
The summarized financial information provided to us by Iroquois, for the period from the June 1, 2017 acquisition date through December 31, 2017which is not considered a significant equity investee under Regulation SX-3-09, is as follows:


(millions of dollars)

At December 31,
2017

ASSETS
Cash and cash equivalents86
Other current assets36
Plant, property and equipment, net591
Other assets8

721


LIABILITIES AND PARTNERS' EQUITY



Current liabilities17
Net long-term debt, including current maturities(a)329
Other non-current liabilities9
Partners' equity366

721


Period of 7 months ended December 31 (millions of dollars)

2017 

Transmission revenues110 
Operating expenses(32)
Depreciation(17)
Financial charges and other(9)

Net income52 

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Table of Contents
December 31 (millions of dollars)
20202019
ASSETS
Cash and cash equivalents25 43 
Other current assets36 36 
Property, plant and equipment, net506 570 
Other assets20 16 
587 665 
LIABILITIES AND PARTNERS’ EQUITY
Current liabilities20 34 
Net long-term debt, net (a)
314 317 
Other non-current liabilities21 20 
Partners’ equity232 294 
587 665 
Year ended December 31 (millions of dollars)
202020192018
Transmission revenues183 180 194 
Operating expenses(59)(58)(57)
Depreciation(30)(29)(29)
Financial charges and other(15)(11)(14)
Net income79 82 94 
(a)
Includes current maturities of $4$5 million as of December 31, 2017.

2020 (December 31, 2019 -$3 million).

NOTE 6 REVENUES
Disaggregation of Revenues
For the year ended December 31, 2020, 2019 and 2018, effectively all of the Partnership’s revenues were from capacity arrangements and transportation contracts with customers as discussed under Note 2 - Significant Accounting Policies.
During the fourth quarter of 2018, Bison received an unsolicited offer from Tenaska Marketing Ventures (Tenaska) regarding the termination of its contract. Also, during 2018, through a Permanent Capacity Release Agreement, Tenaska assumed Anadarko Energy Services Company’s (Anadarko) ship-or-pay contract obligation on Bison, which was the largest contract on Bison. Bison and Tenaska mutually agreed to terms which included a non-refundable payment to Bison of $95.4 million in December 2018 in exchange for the termination of all its contract obligations with Bison. Following the amendment of its tariff to enable this transaction, another customer executed a similar agreement to terminate its contract on Bison in exchange for a non-refundable payment to Bison of approximately $2.0 million in December 2018. At the termination of the contracts, Bison was released from performing any future services with the 2 customers and as such, the amounts received were recorded in revenue in 2018. Accordingly, the $97 million we received from contract terminations was considered as revenue from capacity and transportation contracts with customers and therefore no further disaggregation of revenue is needed (See also related discussion under Note 7 - Plant Property and Equipment).
As noted under Note 2 - Significant Accounting Policies, a portion of our revenues collected may be subject to refund when a rate proceeding is ongoing or as part of a rate case settlement with customers. We use our best estimate based on the facts and circumstances of the proceeding to provide for allowances for these potential refunds in the revenue we recognized. Accordingly, as part of the 2018 GTN Settlement, in 2018, we issued a $10 million refund that was allocated amongst GTN's firm customers. The refund was recognized as an offset against revenue in the income statement for the year ended December 31, 2018.
Contract Balances
All of the Partnership’s contract balances pertain to receivables from contracts with customers amounting to $36 million at December 31, 2020 (December 31, 2019 - $37 million) and are recorded as Trade accounts receivable and reported as “Accounts receivable and other” in the Partnership’s consolidated balance sheet (Refer to Note 20).
Additionally, our accounts receivable represents the Partnership’s unconditional right to consideration for services completed which includes billed and unbilled accounts.
Right to invoice practical expedient
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Table of Contents
In the application of the right to invoice practical expedient, the Partnership’s revenues from regulated capacity arrangements are recognized based on rates specified in the contract. Therefore, the amount invoiced, which includes the capacity contracted and variable volume of natural gas transported, corresponds directly to the value the customer received. These revenues are recognized on a monthly basis once the Partnership’s performance obligation to provide capacity has been satisfied.
NOTE 7 PROPERTY, PLANT PROPERTY AND EQUIPMENT

The following table includes property, plant property and equipment of our consolidated entities:

  
2017
 
2016(a)

  
    
Accumulated
 
Net Book
   
Accumulated
 
Net Book
  
December 31 (millions of dollars) 
Cost
 
Depreciation
 
Value
 
Cost
 
Depreciation
 
Value
  

Pipeline 2,577 (962)1,615 2,540 (879)1,661  
Compression 533 (165)368 519 (148)371  
Metering and other 182 (54)128 205 (61)144  
Construction in progress 12  12 4  4  

  3,304 (1,181)2,123 3,268 (1,088)2,180  

20202019
December 31 (millions of dollars)
CostAccumulated
Depreciation
Net Book
Value
CostAccumulated
Depreciation
Net Book
Value
Pipeline1,910 (982)928 1,907 (929)978 
Compression730 (210)520 584 (202)382 
Metering and other (a)
208 (58)150 180 (56)124 
Construction in progress149  149 44 — 44 
2,997 (1,250)1,747 2,715 (1,187)1,528 
(a)
RecastIncludes the commercial system purchase described under Note 17 related to consolidate PNGTS (Refer to Notes 2 and 7).

NOTE 7    ACQUISITIONS

2017 Acquisition

On June 1, 2017, the Partnership acquired from subsidiaries of TransCanada a 49.34 percent interest in Iroquois, including an option to acquire a further 0.66 percent interest in Iroquois, together with an additional 11.81 percent interest in PNGTS resulting in the Partnership owning a 61.71 percent interest in PNGTS (the 2017 Acquisition). The total purchase price of the 2017 Acquisition was $765 million plus final purchase price adjustmentsour consolidated entities amounting to $50 million. The purchase price consisted of (i) $710 million for the Iroquois interest (less $164 million, which reflected our 49.34 percent share of Iroquois outstanding debt on June 1, 2017), (ii) $55 million for the additional

F-18    TC PipeLines, LPAnnual Report2017



11.81 percent interest in PNGTS (less $5 million, which reflected our 11.81% proportionate share in PNGTS' outstanding debt on June 1, 2017) (iii) final working capital adjustments for Iroquois and PNGTS amounting to $19$26 million and $3 million, respectively and (iv) additional consideration of $28 million for the surplus cash on Iroquois' balance sheet. Additionally, the Partnership paid $1,000 for the option to acquire TransCanada's remaining 0.66 percent interest in Iroquois. The Partnership funded the cashdoes not include our portion of the 2017 Acquisition through a combinationcapital expenditure related to our equity investment in Great Lakes, amounting to $12 million.

2018 Impairment of proceeds fromBison’s long-lived assets
At December 31, 2018, the May 2017 public debt offeringPartnership performed an impairment analysis on Bison’s long-lived assets in connection with the termination of certain customer transportation agreements (refer to Note 8)6 - Revenues).
With the loss of future cash flows resulting from the contract terminations described above and borrowing under our Senior Credit Facility.

At the datepersistence of unfavorable market conditions which inhibited systems flows on the 2017 Acquisition, there was significant cash on Iroquois' balance sheet. Pursuant topipeline during the Purchase and Sale Agreement associated with the acquisitionfourth quarter of the Iroquois interest, as amended, the Partnership agreed to pay $28 million plus interest to TransCanada on August 1, 2017 for its 49.34 percent share of the cash determined to be surplus to Iroquois' operating needs.

Iroquois' partners adopted a distribution resolution to address the surplus cash on its balance sheet post-closing. The Partnership expects to receive the $28 million of unrestricted cash as part of its quarterly distributions from Iroquois over 11 quarters under the terms of the resolution, which began with Iroquois' second quarter 2017 distribution on August 1, 2017. As of February 26, 2018, the Partnership has received approximately $7.8recognized an impairment charge of $537 million relating to the remaining carrying value of the expected $28 million, of which $5.2 millionBison’s property, plant and equipment after determining that it was received in 2017 and $2.6 million was received on February 1, 2018 (Refer to Note 25).

no longer recoverable. The acquisition of a 49.34 percent interest in Iroquois was accounted for as a transaction between entities under common control, whereby the equity investment in Iroquoisimpairment charge was recorded at TransCanada's carrying value andunder Impairment of long-lived assets line on the total excess purchase price paid was recorded as a reduction in Partners' Equity.

Iroquois' net purchase price was allocated as follows:

(millions of dollars)



Net Purchase Price(a)593
Less: TransCanada's carrying value of Iroquois at June 1, 2017223

Excess purchase price(b)370

(a)
Total purchase priceConsolidated statement of $710 million plus final working capital adjustment of $19 million and the additional consideration on Iroquois surplus cash amounting to approximately $28 million less the assumption of $164 million of proportional Iroquois debt by the Partnership.

(b)
The excess purchase price of $370 million was recorded as a reduction in Partners' Equity.

The acquisition of an additional 11.81 percent interest in PNGTS, which resulted in the Partnership owning 61.71 percent in PNGTS, was accounted for as a transaction between entities under common control, similar to a pooling of interests, whereby assets and liabilities of PNGTS were recorded at TransCanada's carrying value and the Partnership's historical financial information, except net income per common unit, was recast to consolidate PNGTS for all periods presented.

The PNGTS purchase price was recorded as follows:

(millions of dollars)



Current assets25
Property, plant and equipment, net294
Current liabilities(4)
Deferred state income taxes(10)
Long-term debt, including current portion(41)

264
Non-controlling interest(100)
Carrying value of pre-existing Investment in PNGTS(132)

TransCanada's carrying value of the acquired 11.81 percent interest at June 1, 201732
Excess purchase price over net assets acquired(a)21

Total cash consideration(b)53

(a)
The excess purchase price of $21 million was recorded as a reduction in Partners' Equity.

(b)
Total purchase price of $55 million plus the final working capital adjustment of $3 million less the assumption of $5 million of proportional PNGTS debt by the Partnership.

operations.


TC PipeLines, LPAnnual Report2017    2020F-19


2016 PNGTS Acquisition

On January 1, 2016, the Partnership acquired a 49.9 percent interest in PNGTS from a subsidiaryTable of TransCanada. The total purchase price of the PNGTS Acquisition was $228 million and consisted of $193 million in cash (including the final purchase price adjustment of $5 million) and the assumption of $35 million in proportional PNGTS debt.

The Partnership funded the cash portion of the transaction using proceeds received in 2015 from our ATM Program and additional borrowings under our Senior Credit Facility. The purchase agreement provides for additional payments to TransCanada ranging from $5 million up to a total of $50 million if pipeline capacity is expanded to various thresholds during the fifteen-year period following the date of closing.

The acquisition was accounted for as a transaction between entities under common control, whereby the equity investment in PNGTS was recorded at TransCanada's carrying value and the total excess purchase price paid was recorded as a reduction in Partners' Equity.

The net purchase price was allocated as follows:

(millions of dollars)



Net Purchase Price(a)193
Less: TransCanada's carrying value of PNGTS' net assets at January 1, 2016120

Excess purchase price(b)73

(a)
Total purchase price of $228 million less the assumption of $35 million of proportional PNGTS debt by the Partnership.

(b)
The excess purchase price of $73 million was recorded as a reduction in Partners' Equity.

2015 GTN Acquisition

On April 1, 2015, the Partnership acquired the remaining 30 percent interest in GTN from a subsidiary of TransCanada (2015 GTN Acquisition), which resulted in GTN being wholly-owned by the Partnership. The total purchase price of the 2015 GTN Acquisition was $446 million plus the final purchase price adjustment of $11 million, for a total of $457 million. The purchase price consisted of $264 million in cash (including the final purchase price adjustment of $11 million), the assumption of $98 million in proportional GTN debt and the issuance of 1,900,000 new Class B units to TransCanada valued at $50 each, representing a limited partner interest in the Partnership with a total value of $95 million.

The Partnership funded the cash portion of the transaction using a portion of the proceeds received on our March 13, 2015 debt offering (refer to Note 8). The Class B units entitle TransCanada to a distribution based on 30 percent of GTN's annual distributions as follows: (i) 100 percent of distributions above $20 million through March 31, 2020; and (ii) 25 percent of distributions above $20 million thereafter. Under the terms of the Third Amended and Restated Agreement of Limited Partnership of the Partnership (Partnership Agreement), the Class B distribution was initially calculated to equal 30 percent of GTN's distributable cash flow for the nine months ended December 31, 2015, less $15 million.

Prior to this transaction, the remaining 30 percent interest held by a subsidiary of TransCanada was reflected as a non-controlling interest in the Partnership's consolidated financial statements. The 2015 GTN Acquisition of this already-consolidated entity was accounted as a transaction between entities under common control, similar to a pooling of interests, whereby the acquired interest was recorded at TransCanada's carrying value and the total excess purchase price paid was recorded as a reduction in Partners' Equity.

The net purchase price was allocated as follows:

(millions of dollars)



Net Purchase Price(a)359
Less: TransCanada's carrying value of non-controlling interest at April 1, 2015232

Excess purchase price(b)127

(a)
Total purchase price of $457 million less the assumption of $98 million of proportional GTN debt by the Partnership.

(b)
The excess purchase price of $127 million was recorded as a reduction in Partners' Equity.

Our General Partner also contributed approximately $2 million to maintain its effective two percent interest in the Partnership.

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Contents

NOTE 8 DEBT AND CREDIT FACILITIES

(millions of dollars) 2017 Weighted Average
Interest Rate for the
Year Ended
December 31, 2017
 2016(b) Weighted Average
Interest Rate for the
Year Ended
December 31, 2016(b)
 

 
TC PipeLines, LP         
 Senior Credit Facility due 2021 185 2.41% 160 1.72% 
 2013 Term Loan Facility due 2022 500 2.33% 500 1.73% 
 2015 Term Loan Facility due 2020 170 2.22% 170 1.63% 
 4.65% Unsecured Senior Notes due 2021 350 4.65%(a)350 4.65%(a)
 4.375% Unsecured Senior Notes due 2025 350 4.375%(a)350 4.375%(a)
 3.90% Unsecured Senior Notes due 2027 500 3.90%(a)  
GTN         
 5.29% Unsecured Senior Notes due 2020 100 5.29%(a)100 5.29%(a)
 5.69% Unsecured Senior Notes due 2035 150 5.69%(a)150 5.69%(a)
 Unsecured Term Loan Facility due 2019 55 2.02% 65 1.43% 
PNGTS         
 5.90% Senior Secured Notes due 2018 30 5.90%(a)53 5.90%(a)
Tuscarora         
 Unsecured Term Loan due 2020 25 2.27% 10 1.64% 
 3.82% Series D Senior Notes due 2017   12 3.82%(a)

 
  2,415   1,920   
Less: unamortized debt issuance costs and debt discount 12   9   
Less: current portion 51(d)  52(c)  

 
  2,352   1,859   

 
(millions of dollars)2020Weighted Average Interest Rate for the Year Ended December 31, 20202019Weighted Average Interest Rate for the Year Ended December 31, 2019
TC PipeLines, LP
Senior Credit Facility due 20210 0 
2013 Term Loan Facility due 2022450 1.87 %450 3.52 %
4.65% Unsecured Senior Notes due 2021350 
(c)
4.65 %(a)350 4.65 %(a)
4.375% Unsecured Senior Notes due 2025350 4.375 %(a)350 4.375 %(a)
3.90% Unsecured Senior Notes due 2027500 3.90 %(a)500 3.90 %(a)
GTN
5.29% Unsecured Senior Notes due 20200 0 100 5.29 %(a)
5.69% Unsecured Senior Notes due 2035150 5.69 %(a)150 5.69 %(a)
3.12% Series A Senior Notes due 2030175 3.12 %(a)
PNGTS
Revolving Credit Facility due 202325 1.88 %39 3.47 %
2.84% Series A Senior Notes due 2030125 2.84 %(a)
Tuscarora
Unsecured Term Loan due 202123 2.13 %23 3.39 %
North Baja
Unsecured Term Loan due 202150 1.70 %50 3.34 %
2,198 2,012 
Less: unamortized debt issuance costs and debt discount7 
Less: current portion423 (b)123 
1,768 1,880 
(a)
Fixed interest rate.

(b)
Recast to consolidate PNGTS (Refer to Notes 2 and 7).

(c)
Includes the PNGTS portionPartnership's 4.65% Unsecured Senior Notes due June 15, 2021, Tuscarora’s Unsecured Term Loan due August 20, 2021 and North Baja's Unsecured Term Loan due December 19, 2021.
(c)Refer to Note 21- Subsequent events for more details on the Partnership's announcement on its intention to exercise its option to redeem this Unsecured Senior Notes at December 31, 2016 amounting to $5.5 million that was paid on January 3, 2017.

(d)
Includes the PNGTS portion due at December 31, 2017 amounting to $5.8 million that was paid on January 2, 2018.

March 15, 2021.

TC PipeLines, LP

On November 10, 2016, the Partnership's

The Partnership’s Senior Credit Facility was amended to extend the maturity period through November 10, 2021. The Facility consists of a $500 million senior revolving credit facility with a banking syndicate, under which $185 million was0 borrowings were outstanding at December 31, 2017 (December 31, 2016 – $160 million),2020, leaving $315$500 million available for future borrowing.

At the Partnership'sPartnership’s option, the interest rate on the outstanding borrowings under the Senior Credit Facility may be the lenders'lenders’ base rate or the London Interbank Offered Rate (LIBOR)LIBOR plus, in either case, an applicable margin that is based on the Partnership'sPartnership’s long-term unsecured credit ratings. The Senior Credit Facility permits the Partnership to specify the portion of the borrowings to be covered by specific interest rate options and, for LIBOR-based borrowings, to specify the interest rate period. The Partnership is required to pay a commitment fee based on its credit rating and on the unused principal amount of the commitments under the Senior Credit Facility. The Senior Credit Facility has a feature whereby at any time, so long as no event of default has occurred and is continuing, the Partnership may request an increase in the Senior Credit Facility of up to $500 million, but no lender has an obligation to increase their respective share of the facility.

The LIBOR-based interest rate on the Senior Credit Facility was 2.62 percent at December 31, 2017 (December 31, 2016 – 1.92 percent).

On July 1, 2013, the Partnership entered into a term loan agreement with a syndicate of lenders for a $500 million term loan credit facility (2013 Term Loan Facility). On July 2, 2013, the Partnership borrowed $500 million under the 2013 Term Loan Facility, to pay a portion of the purchase price of the 2013 Acquisition, maturing originally on July 1, 2018.

On September 29, 2017, the Partnership's 2013Partnership’s term loan credit facility under a term loan agreement (2013 Term Loan FacilityFacility) was amended to extend the maturity period through October 2, 2022. The 2013 Term Loan Facility bears interest based, at the Partnership'sPartnership’s election, on the LIBOR or the base rate plus, in either case, an applicable margin. The base rate equals the highest of (i) SunTrust Bank'sBank’s prime rate, (ii) 0.50 percent above the U.S. federal funds rate and (iii) 1.00 percent above one-month LIBOR. The applicable margin for the term loan is based on the Partnership'sPartnership’s senior debt rating and ranges between 1.125 percent and 2.00 percent for LIBOR borrowings and 0.125 percent and 1.00 percent for base rate borrowings.

TC PipeLines, LPAnnual Report2017    F-21


On June 26, 2019, the Partnership repaid $50 million of the principal balance under its 2013 Term Loan Facility using proceeds from Northern Border's additional distribution (see Note 5). Additionally, in conjunction with this repayment, the Partnership also terminated an equivalent amount in interest rate swaps that were used to hedge this facility at a rate of 2.81 percent. As of December 31, 2017,2020, the variable interest rate exposure related to 2013 Term Loan Facility was hedged by fixed interest rate swap arrangements and our effective interest rate was 2.313.26 percent (2016(20192.313.26 percent). Prior to hedging activities, the LIBOR-based interest rate was 2.621.40 percent at December 31, 20172020 (December 31, 201620191.872.94 percent).

On September 30, 2015, the Partnership entered into an agreement for a $170 million term loan credit facility (2015 Term Loan Facility).

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Table of Contents
The Partnership borrowed $170 million under the 2015 Term Loan Facility to refinance its Short-Term Loan Facility which matured on September 30, 2015. On September 29, 2017, the Partnership's 2015 Term Loan Facility that was due on October 1, 2018 was amended to extend the maturity period through October 1, 2020. The LIBOR-based interest rate on the 2015 Term Loan Facility was 2.51 percent at December 31, 2017 (December 31, 2016 – 1.77 percent).

The 2013 Term LoanSenior Credit Facility and the 20152013 Term Loan Facility (Term Loan Facilities) and the Senior Credit Facility require the Partnership to maintain a certain leverage ratio (debtdebt to adjusted cash flow [net income plus cash distributions received, extraordinary losses, interest expense, expense for taxes paid or accrued, and depreciation and amortization expense less equity earnings and extraordinary gains])leverage ratio of no greater than 5.00 to 1.00 for each fiscal quarter, except for the fiscal quarter and the two following fiscal quarters in which one or more acquisitions has been executed, in which case the leverage ratio is to be no greater than 5.50 to 1.00. The leverage ratio was 4.703.85 to 1.00 as of December 31, 2017.

2020.

The Senior Credit Facility and the 2013 Term Loan FacilitiesFacility contain additional covenants that include restrictions on entering into mergers, consolidations and sales of assets, granting liens, material amendments to the Partnership Agreement, incurrence of additional debt by the Partnership'sPartnership’s subsidiaries and distributions to unitholders. Upon any breach of these covenants, amounts outstanding under the Senior Credit Facility and the 2013 Term Loan FacilitiesFacility may become immediately due and payable.

On March 13, 2015, the Partnership closed a $350 million public offering of senior unsecured notes bearing an interest rate of 4.375 percent maturing March 13, 2025. The net proceeds of $346 million were used to fund a portion of the 2015 GTN Acquisition (Refer to Note 7) and to reduce the amount outstanding under our Senior Credit Facility. The indenture for the notes contains customary investment grade covenants.


On May 25, 2017, the Partnership closed a $500 million public offering of senior unsecured notes bearing an interest rate of 3.90 percent maturing May 25, 2027. The net proceeds of $497 million were used to fund a portion of the 2017 Acquisition (Refer to Note 7).acquisition of a 49.34 percent interest in Iroquois, together with an additional 11.81 percent interest in PNGTS. The indenture for the notes contains customary investment grade covenants.

PNGTS

On April 5, 2018, PNGTS entered into a revolving credit agreement under which PNGTS has the ability to borrow up to $125 million with a variable interest rate based on LIBOR. The credit agreement matures on April 5, 2023 and requires PNGTS to maintain a leverage ratio not greater than 5.00 to 1.00. The leverage ratio was 1.99 to 1.00 as of December 31, 2020. The facility is being utilized by PNGTS primarily to fund the costs of its expansion projects and for general partnership purposes. As of December 31, 2020, $25 million was drawn on the Revolving Credit Facility and the LIBOR-based interest rate was 1.28 percent (December 31, 2019 - 2.99 percent).

On October 8, 2020, PNGTS entered into a Note Purchase and Private Shelf Agreement whereby PNGTS issued $125 million 10-year Series A Senior Notes (PNGTS Series A Notes) with a coupon rate of 2.84% per annum and entered into a 3 year private shelf agreement for an additional $125 million of Senior Notes (PNGTS Private Shelf Facility). The PNGTS Series A Notes do not require any principal payments until maturity on October 8, 2030. Proceeds from the PNGTS' Senior Secured Notes are securedSeries A Note issuance were used to repay the outstanding balance of PNGTS' revolving credit facility and for general partnership purposes including funding growth capital expenditures. PNGTS expects to draw the remaining $125 million available under the PNGTS Private Shelf Facility by the end of the third quarter of 2021 to refinance amounts funded on its revolving credit facility for costs associated with the Westbrook XPress Project. The PNGTS long-term firm shipper contractsPrivate Shelf Facility and its partners' pledgePNGTS Series A Notes contain a covenant that limits total debt to no greater than 65 percent of their equityPNGTS’ total capitalization and requires PNGTS to maintain a guaranteeleverage ratio of no greater than 5.00 to 1.00. The ratio of debt service for six months. PNGTS is restricted underto capitalization was 37 percent and the termsleverage ratio was 1.99 to 1.00 as of its note purchase agreement from making cash distributions unless certain conditions are met. Before a distribution can be made, the debt service reserve account must be fully funded and PNGTS' debt service coverage ratio for the preceding and succeeding twelve months must be 1.30 or greater. At December 31, 2017, the debt service coverage ratio was 1.72 for the twelve preceding months and 1.53 for the twelve succeeding months. Therefore, PNGTS was not restricted to make any cash distributions.

2020.

GTN

On June 1, 2015,2020, GTN's $100 million 5.29% Unsecured Senior Notes became due and were refinanced through a Note Purchase and Private Shelf Agreement whereby GTN issued $175 million of 10-year Series A Senior Notes (GTN Series A Notes) with a coupon rate of 3.12% per annum and entered into a 3-year private shelf agreement for an additional $75 million unsecured variable rate term loan facility (Unsecured Term Loanof Senior Notes (GTN Private Shelf Facility), which requires yearly. The GTN Series A Notes do not require any principal payments until its maturity on June 1, 2019.2030. Proceeds from the GTN Series A Note issuance were used to repay the outstanding balance of the 5.29% Unsecured Senior Notes and the remaining proceeds is being used to fund the GTN XPress capital expenditures. GTN expects to draw the remaining $75 million available under the GTN Private Shelf Facility by the end of 2023, the estimated completion date of GTN XPress. The variable interest is based on LIBOR plus an applicable margin. The LIBOR-based interest rate on the Unsecured Term LoanGTN Private Shelf Facility was 2.31and GTN Series A Notes contain a covenant that limits total debt to no greater than 65 percent at December 31, 2017 (December 31, 2016 – 1.57 percent).of total capitalization. GTN's Unsecured Senior Notes along with this new Unsecured Term Loan Facility contain a covenant that limits total debt to no greater than 70 percent of GTN'sGTN’s total capitalization. GTN'sGTN’s total debt to total capitalization ratio at December 31, 2017 is 44.62020 was 36.8 percent.

Tuscarora


On August 21, 2017, Tuscarora refinanced all of its outstanding debt by amending its existingJuly 23, 2020, Tuscarora's $23 million variable rate Unsecured Term Loan Facility and issuing a new $25 million variable rate term loan that will require yearly principal payments and will mature on(Unsecured Term Loan) was amended to extend the maturity date to August 21, 2020. Tuscarora's20, 2021 under generally the same terms. Tuscarora’s Unsecured Term Loan contains a covenant that requires Tuscarora to maintain a debt service coverage ratio (cash available from operations divided by a sum of interest expense and principal payments) of greater than or equal to 3.00 to 1.00. As of December 31, 2017,2020, the ratio was 11.0931.16 to 1.00.

The LIBOR-based interest rate applicable to Tuscarora’s Unsecured Term Loan Facility was 2.15 percent at December 31, 2020 (December 31, 2019 - 2.82 percent).

North Baja
On December 19, 2018, North Baja entered into a $50 million unsecured variable rate term loan facility, which matures on December 19, 2021. The net proceeds were used for general partnership purposes. The variable interest rate is based on LIBOR plus an applicable margin. The LIBOR-based interest rate on the Tuscarora's Unsecured Term Loan Facilitythis term loan facility was 2.491.23 percent at December 31, 20172020 (December 31, 2016 – 1.902019 - 2.77 percent).

North Baja’s Term Loan Facility contains a covenant that limits total debt to no greater than 70 percent of North Baja’s total capitalization. North Baja’s total debt to total capitalization ratio at December 31, 2020 is 40.8 percent.



TC PipeLines, LP Annual Report 2020F-21

Partnership (TC PipeLines, LP and its subsidiaries)

At December 31, 2017,2020, the Partnership was in compliance with its financial covenants, in addition to the other covenants which include restrictions on entering into mergers, consolidations and sales of assets, granting liens, material amendments to the Partnership Agreement, incurring additional debt and distributions to unitholders.

F-22    TC PipeLines, LPAnnual Report2017


The principal repayments required by the Partnership on its consolidated debt are as follows:

(millions of dollars)
  
 

2018 51 
2019 36 
2020 293 
2021 535 
2022 500 
Thereafter 1,000 

  2,415 

(millions of dollars)
2021423 
2022450 
202325 
2024
2025350 
Thereafter950 
2,198 

NOTE 9 OTHER LIABILITIES


December 31 (millions of dollars)
 
2017
 
2016
 

Regulatory liabilities 26 25 
Other liabilities 3 3 

  29 28 

December 31 (millions of dollars)
20202019
Regulatory liabilities38 29 
Other liabilities9 
47 36 
The Partnership collects estimated future removal costs related to its transmission and gathering facilities in its current rates (also known as "negative salvage"“negative salvage”) and recognizes regulatory liabilities in this respect inon the balance sheet. Estimated costs associated with the future removal of transmission and gathering facilities are collected through depreciation as allowed by FERC. These amounts do not represent asset retirement obligations as defined by FASB ASCAccounting Standards Codification (ASC) 410,Accounting for Asset Retirement Obligations.

Obligations. (Refer to Note 2)

NOTE 10 PARTNERS'PARTNERS’ EQUITY

At December 31, 2017,2020, the Partnership had 70,573,42371,306,396 common units outstanding, of which 53,488,59254,221,565 were held by non-affiliates and 17,084,831 common units were held by subsidiaries of TransCanada,TC Energy, including 5,797,106 common units held by our General Partner. Additionally, TransCanada,TC Energy, through our General Partner, owns 100 percent of our IDRs and an effective twoa 2 percent general partner interest in the Partnership. TransCanadaTC Energy also holds 100 percent of our 1,900,000 outstanding Class B units.

ATM

At-the-Market Equity Issuance Program (ATM Program)

In August 2014,2018, the Partnership launchedissued 0.7 million common units under its $200 million ATM program pursuant toprevious At-the-Market Equity Issuance Program (ATM Program), which allowed the Partnership may from time to time to offer and sell, through sales agents, common units representing limited partner interests.

On August 5, 2016, the Partnership entered into a new $400 million Equity Distribution Agreement (EDA) with five financial institutions (the Managers). Sales of the common units will be issued pursuant to In 2018, the Partnership's shelf registration statement on Form S-3 (Registration No. 333-211907), which was declared effective by the SEC on August 4, 2016.

In 2017, the Partnership issued 3.2 million common units under the ATM Program generatinggenerated net proceeds of approximately $173$39 million, plus an additional $3$1 million from the General Partner to maintain its effective two2 percent interest. The commissions to our sales agents were approximately $2 million.immaterial. The net proceeds were used to repay a portion of the borrowings under the Senior Credit Facility and for general partnership purposes.

In 2016, the Partnership issued 3.1 million common units underAugust 2019, the ATM Program generating net proceedsexpired with 0 common unit issuances in 2019.
Issuance of approximately $164 million, plus an additional $3 million from the General PartnerClass B units
The Class B Units issued on April 1, 2015 to maintain its effective two percent interest. The commissions to our sales agents were approximately $2 million. The net proceeds were used to repayfinance a portion of the borrowings underPartnership’s acquisition of the Senior Credit Facility for the 2016 PNGTS Acquisitionremaining 30 percent interest of GTN from TC Energy represent a limited partner interest in us and for general partnership purposes. The 3.1entitles TC Energy to an annual distribution based on 30 percent of GTN’s annual distributions as follows: (i) 100 percent of distributions above $20 million common units issued include the 1.6through March 31, 2020; and (ii) 25 percent of distributions above $20 million common units subjectthereafter, which equates to rescission as discussed below.

In 2015, the Partnership issued 0.743.75 percent of distributions above $20 million common units under the ATM Program generating net proceeds of approximately $43 million, plus an additional $1 million from the General Partner to maintain its effective two percent interest. The commissions to our sales agents were approximately $0.4 million. The net proceeds were used for general partnership purposes.

TC PipeLines, LPAnnual Report2017    F-23


Common unit issuance subject to rescission

In connection with a late filing of an employee-related Form 8-K with the SEC in March 2016, the Partnership became ineligible to use the then effective shelf registration statement upon filing of its Annual Report on Form 10-K for the year ended December 31, 2015. As a result, it was determined that the purchasers of the 1.6 million common units that were issued from March 8, 2016 to May 19, 2016 under the Partnership's ATM program may have had a rescission right for an amount equal to the purchase price paid for the units, plus statutory interest and less any distributions paid, upon the return of such units to the Partnership. The Securities Act of 1933, as amended (Securities Act) generally requires that any claim brought for a violation of Section 5 of the Securities Act be brought within one year of violation.

At December 31, 2016, $83 million was recorded as common units subject to rescission on the consolidated balance sheet. The Partnership classified the 1.6 million common units that were sold under its ATM program from March 8, 2016 up to and including May 19, 2016, which may have been subject to rescission rights, outside of equity given the potential redemption feature which was not within the control of the Partnership. These units were treated as outstanding for financial reporting purposes.

No unitholder claimed or attempted to exercise any rescission rights prior to their expiry dates and the final rights related to the sales of such units expired on May 19, 2017. As a result of the expiration of these rights, the $83 million was reclassified back to partners' equity. At December 31, 2017, there were no outstanding common units subject to rescission on the Partnership's consolidated balance sheet.

Issuance of Class B units

On April 1, 2015, we issued Class B units to TransCanada to finance a portion of the 2015 GTN Acquisition. The Class B units entitle TransCanada to an annual distribution which is an amount based on 30 percent of cash distributions from GTN exceeding certain annual thresholds (refer to Note 7).2020. The Class B units contain no mandatory or optional redemption features and are also non-convertible, non-exchangeable, non-voting and rank equally with common units upon liquidation.

Additionally, the Class B Distribution was reduced by 35 percent, which is equivalent to the percentage by which distributions payable to the common units were reduced in 2018. The Class B units'Reduction was implemented during the first quarter of 2018 following the Partnership’s common unit distribution reduction of 35 percent from its fourth quarter 2017 distribution level of $1.00 per common unit. The Class B Reduction will continue to apply for any particular calendar year until distributions payable in respect of common units for such calendar year equal or exceed $3.94 per common unit.
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The Class B units’ equity account is increased by the excess of 30 percent of GTN's distributions over“Class B Distribution,” less the annual threshold“Class B Reduction,” if any, and until such amount is declared for distribution and paid everyin the first quarter of the subsequent year.

For the year ended December 31, 2020, there was 0 Class B Distribution as the thresholds noted above were not exceeded. For the years ended December 31, 2017, 20162019 and 2015,2018, the Class B units'units’ equity account was increased by $15 million, $22$8 million and $12$13 million, respectively. These amounts equal 30 percent of GTN's total distributable cash flow above the $20 million threshold in 2017 and 2016 and the $15 million threshold in 2015 (refer(Refer to Notes 13 and 14).

NOTE 11 ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)

The changes in accumulated other comprehensive income (loss) (AOCI)AOCI by component are as follows:


(millions of dollars)
 
Cash flow
hedges(a)
 
Equity
Investments
 
Total
  

Balance at December 31, 2014 (5) (5) 
Change in fair value of cash flow hedges     
Amounts reclassified from AOCI     
PNGTS' amortization of realized loss on derivative instrument (Note 19) 1  1  

Net other comprehensive income 1  1  

Balance at December 31, 2015 (4) (4) 
Change in fair value of cash flow hedges 3  3  
Amounts reclassified from AOCI (2) (2) 
PNGTS' amortization of realized loss on derivative instrument (Note 19) 1  1  

Net other comprehensive income 2  2  

Balance at December 31, 2016 (2) (2) 
Change in fair value of cash flow hedges 5  5  
Amounts reclassified from AOCI     
PNGTS' amortization of realized loss on derivative instrument (Note 19) 1  1  
Other comprehensive income – effects of Iroquois' retirement benefit plans  1 1  

Net other comprehensive income 6 1 7  

Balance as of December 31, 2017 4 1 5  

(a)
Recast to consolidate PNGTS (Refer to in Notes 2 and 7). Additionally, AOCI as presented here is net of non-controlling interest on PNGTS.

F-24    TC PipeLines, LPAnnual Report2017


(millions of dollars)Cash flow
hedges
Equity
Investments
Total
Balance at December 31, 20175 
Change in fair value of cash flow hedges(2)(2)
Amounts reclassified from AOCI5 
PNGTS’ amortization of realized loss on derivative instrument (Note 19)
1 
Other comprehensive income - effects of Iroquois’ retirement benefit plans(1)(1)
Net other comprehensive income(1)3 
Balance at December 31, 20188 
Change in fair value of cash flow hedges(13)(13)
Amounts reclassified from AOCI(1)(1)
Other comprehensive loss - effects of Iroquois’ retirement benefit plans1 
Net other comprehensive income (loss)(14)(13)
Balance as of December 31, 2019(6)(5)
Change in fair value of cash flow hedges(16)(16)
Amounts reclassified from AOCI7 
Other comprehensive income - effects of Iroquois’ retirement benefit plans1 
Net other comprehensive income (loss)(9)(8)
Balance as of December 31, 2020(15)(13)


NOTE 12 FINANCIAL CHARGES AND OTHER


Year ended December 31 (millions of dollars)
 
2017
 
2016(a)
 
2015(a)  
  

Interest expense(b) 83 69 65  
Net realized loss related to the interest rate swaps  3 2  
PNGTS' amortization of realized loss on derivative instrument (Note 19) 1 1 1  
Other (2)(2)(5) 

  82 71 63  

Year ended December 31 (millions of dollars)
202020192018
Interest expense(a)
78 88 95 
Net realized loss (gain) related to the interest rate swaps7 (1)(2)
PNGTS’ amortization of realized loss on derivative instrument (Note 19)
0 
AFUDC - Equity(10)(2)(1)
Other (b)
(2)(2)(1)
73 83 92 
(a)
Recast to consolidate PNGTS (Refer to Notes 2 and 7).

(b)
Interest expense includes amortization of debt issuance costs and discount costs.

costs amounting to approximately $2 million each year ended December 31, 2020, 2019 and 2018.

(b)Includes AFUDC Debt amounting to $1.3 million for the year ended December 31, 2020 (2019 and 2018 - less than $1 million).
NOTE 13 NET INCOME (LOSS) PER COMMON UNIT

Net income (loss) per common unit is computed by dividing net income (loss) attributable to controlling interests, after deduction of net income attributed to PNGTS' former parent, amounts attributable to the General Partner and Class B units, by the weighted average number of common units outstanding.

The amounts allocable to the General Partner equals an amount based upon the General Partner's effective twoPartner’s 2 percent general partner interest, plus an amount equal to incentive distributions. Incentive distributions are paid to the General Partner if quarterly cash distributions on the common units exceed levels specified in the Partnership Agreement (refer(Refer to Note 14).


The amount allocable to the Class B units in 20172020 equals an amount based upon 30 percent of GTN'sGTN’s distributable cash flow during the year ended December 31, 20172020 less $20 million, (2016 –the residual of which is further multiplied by 43.75 percent. This amount is further reduced by the estimated Class B Reduction for 2020, an approximately 35 percent reduction applied to the estimated annual Class B Distribution (December 31, 2019 and 2018 - $20 million; 2015 – $15million less Class B Reduction). During the year ended December 31, 2020, 0 amounts were allocated to the Class B units as the annual threshold was not exceeded (2019 - $8 million, 2018 - $13 million).

TC PipeLines, LP Annual Report 2020F-23

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Net income (loss) per common unit was determined as follows:


(millions of dollars, except per common unit amounts)
 
2017
 
2016
 
2015
  

Net income attributable to controlling interests(a) 252 248 37  
Net income attributable to PNGTS' former parent(a)(b) (2)(4)(24) 

Net income allocable to General Partner and Limited Partners 250 244 13  
Incentive distributions attributable to the General Partner(c) (12)(7)(3) 
Net income attributable to the Class B units(d) (15)(22)(12) 

Net income (loss) allocable to the General Partner and common units 223 215 (2) 
Net income allocable to the General Partner's two percent interest (4)(4)  

Net income (loss) attributable to common units 219 211 (2) 

Weighted average common units outstanding(millions) – basic and diluted 69.2 65.7(e)63.9  
Net income (loss) per common unit – basic and diluted(f) $3.16 $3.21 $(0.03) 

(millions of dollars, except per common unit amounts)202020192018
Net income (loss) attributable to controlling interests284 280 (182)
Amounts attributable to the Class B units (a)
0 (8)(13)
Net income (loss) allocable to the General Partner and common units284 272 (195)
Amounts attributable to General Partner's 2 percent interest(6)(5)
Net income (loss) attributable to common units278 267 (191)
Weighted average common units outstanding (millions) – basic and diluted
71.3 71.3 71.3 
Net income (loss) per common unit – basic and diluted$3.90 $3.74 $(2.68)

(a)
Recast to consolidate PNGTS for years ended December 2016 and 2015 (Refer to Note 2).

(b)
Net income allocable to General and Limited Partners excludes net income attributed to PNGTS' former parent as it was allocated to TransCanada and was not allocable to either the general partner, common units or Class B units.

(c)
Under the terms of the Partnership Agreement, for any quarterly period, the participation of the incentive distribution rights (IDRs) is limited to the available cash distributions declared. Accordingly, incentive distributions allocated to the General Partner are based on the Partnership's available cash during the current reporting period, but declared and paid in the subsequent reporting period.

(d)
As discussed in Note 10, the Class B units entitle TransCanadaTC Energy to a distribution which is an amount based on 30 percent of GTN'sGTN’s distributions after exceeding certain annual thresholds.thresholds and Class B Reduction. The distribution will be payable in the first quarter with respect to the prior year'syear’s distributions. ConsistentThere was 0 Class B Unit distribution declared for 2020. However, consistent with the application of Accounting Standards Codification (ASC) Topic 260 – "Earnings“Earnings per share",share,” the Partnership allocated the Class B units a distribution in an amount equal to 30 percent of GTN'sGTN’s total distributable cash flows during the year ended December 31, 20172019 less the threshold level of $20 million (2016 –(2018 - less $20 million; 2015 –million) and less $15 million). During the year ended December 31, 2017, 30 percent of GTN's total distributable cash flow was $35 million. As a result of exceeding the threshold level of

TC PipeLines, LPAnnual Report2017    F-25


(e)
Includes the common units subject to rescission. These units are treated as outstanding for financial reporting purposes (Refer to Note 10).

(f)
Net income (loss) per common unit prior to recast.

NOTE 14 CASH DISTRIBUTIONS

The Partnership makes cash distributions to its partners with respect to each calendar quarter within 45 days after the end of each quarter. Distributions are based on Available Cash,available cash, as defined in the Partnership Agreement, which includes all cash and cash equivalents of the Partnership and working capital borrowings less reserves established by the General Partner.

Pursuant to the Partnership Agreement, the General Partner receives two2 percent of all cash distributions in regard to its general partner interest and is also entitled to incentive distributions as described below. The unitholders receive the remaining portion of the cash distribution.

The following table illustrates the percentage allocations of available cash from operating surplus between the common unitholders and our General Partner after providing for Class B distributions based on the specified target distribution levels. The percentage interests set forth below for our General Partner include its twoIDRs and 2 percent general partner interest and IDRs, and assume our General Partner has contributed any additional capital necessary to maintain its two2 percent general partner interest. The distributionpercentage interest distributions to the General Partner illustrated below other than in its capacity as a holder of 5,797,106 common units that are in excess of its effective two2 percent general partner interest representsrepresent the IDRs.

    
Marginal Percentage
Interest in Distribution

  
Total Quarterly Distribution
Per Unit Target Amount
 
Common
Unitholders
 
General
Partner
  

Minimum Quarterly Distribution $0.45 98% 2%  
First Target Distribution above $0.45 up to $0.81 98% 2%  
Second Target Distribution above $0.81 up to $0.88 85% 15%  
Thereafter above $0.88 75% 25%  

Marginal Percentage
Interest in Distribution
Total Quarterly Distribution
Per Unit Target Amount
Common
Unitholders
General
Partner
Minimum Quarterly Distribution$0.4598 %%
First Target Distributionabove $0.45 up to $0.8198 %%
Second Target Distributionabove $0.81 up to $0.8885 %15 %
Thereafterabove $0.8875 %25 %
The following table provides information about our distributions (in millions except per unit distributions amounts).

      Limited Partners

 General Partner

    

Declaration Date
 
Payment Date
 
Per Unit
Distribution
 
Common
Units
 
Class B
Units(c)
 
2%
 
IDRs(a)
 
Total Cash
Distribution
  

1/22/2015 2/13/2015 $0.84 $54 $  – $1 $– $55  
4/23/2015 5/15/2015 $0.84 $54 $  – $1 $– $55  
7/23/2015 8/14/2015 $0.89 $56 $  – $2 $1 $59  
10/22/2015 11/13/2015 $0.89 $57 $  – $1 $1 $59  
1/21/2016 2/12/2016 $0.89 $57 $12(d)$1 $1 $71  
4/21/2016 5/13/2016 $0.89 $58 $  – $1 $1 $60  
7/21/2016 8/12/2016 $0.94 $62 $  – $1 $2 $65  
10/20/2016 11/14/2016 $0.94 $63 $  – $1 $2 $66  
1/23/2017 2/14/2017 $0.94 $64 $22(e)$2 $2 $90  
4/25/2017 5/15/2017 $0.94 $65 $  – $1 $2 $68  
7/20/2017 8/11/2017 $1.00 $69 $  – $2 $3 $74  
10/24/2017 11/14/2017 $1.00 $70 $  – $1 $3 $74  
1/23/2018(b)2/13/2018(b)$1.00 $71 $15(f)$2 $3 $91  

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Table of Contents
Limited PartnersGeneral Partner
Declaration DatePayment DatePer Unit
Distribution
Common
Units
Class B
Units(b)
%
IDRs(a)
Total Cash
Distribution
1/23/20182/13/2018$1.00 $71 $15 $$$91 
5/1/20185/15/2018$0.65 $46 $$$$47 
7/26/20188/15/2018$0.65 $46 $$$$47 
10/23/201811/14/2018$0.65 $46 $$$$47 
1/22/20192/11/2019$0.65 $46 $13 $$$60 
4/23/20195/13/2019$0.65 $46 $$$$47 
7/23/20198/14/2019$0.65 $46 $$$$47 
10/22/201911/14/2019$0.65 $46 $$$$47 
1/21/20202/14/2020$0.65 $46 $$$$55 
4/21/20205/12/2020$0.65 $46 $$$$47 
7/23/20208/14/2020$0.65 $46 $$$$47 
10/21/202011/13/2020$0.65 $46 $$$$47 
1/19/2021(c)
2/12/2021(c)
$0.65 $46 $$$$47 
(a)
The distributions paid during the year ended December 31, 20172020 and 2019 included 0 incentive distributions to the General Partner of $10 million (2016 – $6 million, 2015 – $2(2018 - $3 million).

(b)
On February 13, 2018, we paid a cash distribution of $1.00 per unit on our outstanding common units to unitholders of record at the close of business on February 2, 2018 (refer to Note 25).

F-26    TC PipeLines, LPAnnual Report2017


(c)
The Class B units issued by us on April 1, 2015 represent limited partner interests in us and entitle TransCanadaTC Energy to an annual distribution which is an amount based on 30 percent of GTN'sGTN’s annual distributions after exceeding certain annual thresholds and adjustments (refer to Note 7 and 10).

(d)
(c)On February 12, 2016,2021, we paid TransCanada $12 million representing 30 percenta cash distribution of GTN's total distributable cash flows for$0.65 per unit on our outstanding common units to unitholders of record at the nine months ended December 31, 2015 less $15 million.

(e)
On February 14, 2017, we paid TransCanada $22 million representing 30 percentclose of GTN's total distributable cash flows for the year ended December 31, 2016 less $20 millionbusiness on January 29, 2021 (refer to Note 10 and 25)21).

(f)
On February 13, 2018, we paid TransCanada $15 million representing 30 percent of GTN's total distributable cash flows for the year ended December 31, 2017 less $20 million (refer to Note 10 and 25).

NOTE 15 CHANGE IN OPERATING WORKING CAPITAL


Year Ended December 31 (millions of dollars)

 
2017

 
2016(b)

 
2015(b)

  

Change in accounts receivable and other 4 (4)6  
Change in other current assets 2 (4)(1) 
Change in accounts payable and accrued liabilities (7)(a)5(a)(2) 
Change in accounts payable to affiliates (3) (15)(a) 
Change in state income taxes payable   (5) 
Change in accrued interest 2 2 (3) 

Change in operating working capital (2)(1)(20) 

Year Ended December 31 (millions of dollars)
202020192018
Change in accounts receivable and other1 (6)
Change in inventory(1)(2)
Change in other current assets0 (1)
Change in accounts payable and accrued liabilities (a)
5 (11)
Change in accounts payable to affiliates(1)
Change in accrued interest0 (1)
Change in operating working capital4 (3)(3)
(a)
Excludes certain non-cash items primarily related to capital accruals and dropdown costs.

(b)
Recast to consolidate PNGTS (Refer to Notes 2 and 7).
credits.

NOTE 16 TRANSACTIONS WITH MAJOR CUSTOMERS

The following table shows revenues from

For the Partnership's major customers comprisingyear ended December 31, 2020 and 2019, no customer accounted for more than 10 percent of the Partnership's totalour consolidated recasted revenues (refer to Note 2) for the years ended December 31, 2017, 2016revenue and 2015:


Year Ended December 31 (millions of dollars)

 
2017

 

2016

 
2015

 

Anadarko Energy Services Company (Anadarko) 48 48 48 
Pacific Gas and Electric Company (Pacific Gas) 33(a)(b)36(a)42 

trade accounts receivable.

At December 31, 2017 and 2016, Anadarko2018, Tenaska owed the Partnership approximately $4 million, which iswas approximately 10 percent of our consolidated recasted trade accounts receivable (Referreceivable. As noted under Note 6, in 2018, Tenaska assumed Anadarko’s ship-or-pay contract obligation on Bison. After assuming the transportation obligation, Bison accepted an offer from Tenaska to Note 2).

(a)
Less than 10 percent of trade accounts receivable

(b)
Less than 10 percent ofterminate its contract. For the year ended December 31, 2018, revenues from both Anadarko and Tenaska amounted to $144 million, which was approximately 36 percentof our consolidated revenue
revenues.

NOTE 17 RELATED PARTY TRANSACTIONS

The Partnership does not have any employees. The management and operating functions are provided by the General Partner. The General Partner does not receive a management fee in connection with its management of the Partnership.
The Partnership reimburses the General Partner for all costs of services provided, including the costs of employee, officer and director compensation and benefits, and all other expenses necessary or appropriate to the conduct of the business of, and allocable to, the Partnership. Such costs include (i) overhead costs (such as office space and equipment) and (ii) out-of-pocket
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expenses related to the provision of such services. The Partnership Agreement provides that the General Partner will determine the costs that are allocable to the Partnership in any reasonable manner determined by the General Partner in its sole discretion. Total costs charged to the Partnership by the General Partner werewas $4 million for the year ended December 31, 2017 (2016 – $3 million, 2015 – $32020 (2019 - $4 million; 2018 - $4 million).

As operator of most of our pipelines (except Iroquois and the Pipeline facilities jointly owned with MNE on PNGTS joint facilities) TransCanada's(the Joint Facilities)), TC Energy’s subsidiaries provide capital and operating services to our pipeline systems. TransCanada'sTC Energy’s subsidiaries incur costs on behalf of our pipeline systems, including, but not limited to,

TC PipeLines, LPAnnual Report2017    F-27



employee salary and benefit costs, and property and liability insurance costs. The Iroquois pipeline system is operated by Iroquois Pipeline Operating Company, a wholly owned subsidiary of Iroquois. The PNGTS joint facilitiesJoint Facilities are operated by MNOC. Therefore, Iroquois and the PNGTS joint facilitiesJoint Facilities do not receive capital and operating services from TransCanada.

TC Energy.

Capital and operating costs charged to our pipeline systems, except for Iroquois, for the years ended December 31, 2017, 20162020, 2019 and 20152018 by TransCanada'sTC Energy's subsidiaries and amounts payable to TransCanada'sTC Energy's subsidiaries at December 31, 20172020 and 20162019 are summarized in the following tables:


Year ended December 31 (millions of dollars)
 
2017
 
2016
 
2015  
 

Capital and operating costs charged by TransCanada's subsidiaries to:       
 Great Lakes(a) 36 30 30 
 Northern Border(a) 43 32 36 
 PNGTS(a)(b) 9 8 8 
 GTN(a)(c) 34 27 30 
 Bison 6 2 4 
 North Baja 4 4 5 
 Tuscarora 4 5 4 
Impact on the Partnership's net income attributable to controlling interests:       
 Great Lakes 15 13 13 
 Northern Border 16 12 14 
 PNGTS(b) 5 5 5 
 GTN(c) 29 24 25 
 Bison 6 3 4 
 North Baja 4 4 5 
 Tuscarora 4 4 4 

December 31 (millions of dollars)
 
2017
 
2016  
 

Amount payable to TransCanada's subsidiaries for costs charged in the year by:     
 Great Lakes(a) 3 4 
 Northern Border(a) 4 4 
 PNGTS(a)(b) 1 1 
 GTN 3 3 
 Bison 1 1 
 North Baja  1 
 Tuscarora  1 
Year ended December 31 (millions of dollars)
202020192018
Capital and operating costs charged by TC Energy’s subsidiaries to:
Great Lakes (a)
66 47 44 
Northern Border(a)
39 39 36 
PNGTS (a)
6 
GTN68 45 34 
Bison2 
North Baja7 
Tuscarora6 
Impact on the Partnership’s net income attributable to controlling interests:
Great Lakes16 20 19 
Northern Border16 18 16 
PNGTS3 
GTN29 33 28 
Bison2 
North Baja3 
Tuscarora3 
December 31 (millions of dollars)
20202019
Amount payable to TC Energy’s subsidiaries for costs charged in the year by:
Great Lakes (a)
3 
Northern Border(a)
2 
PNGTS (a)
1 
GTN4 
Bison0 
North Baja0 
Tuscarora1 
(a)
Represents 100 percent of the costs.

(b)
Recast to consolidate PNGTS for years ended December 31, 2016 and 2015 (Refer to Note 2).

(c)
In 2015, the Partnership acquired the remaining 30 percent interest in GTN (Refer to Note 7).

Great Lakes

Great Lakes earns significant transportation revenues from TransCanadaTC Energy and its affiliates, some of which are provided at discounted rates, negotiated rates and some at maximum recourse rates.affiliates. For the year ended December 31, 2017,2020, Great Lakes earned 5773 percent of its transportation revenues from TransCanadaTC Energy and its affiliates (2016(20196873 percent; 201520187173 percent). Additionally, included in Great Lakes earned approximately oneLakes’ other revenues for 2018 and 2019 were cost recovery charges to affiliates for the use of office space in the building owned by Great Lakes. These revenues comprised less than 1 percent of its total revenues as affiliated rental revenue in 2017 (2016 – 1 percent; 2015 – 1 percent).

2018 and 2019. The building was sold to a third party in the third quarter of 2019.

At December 31, 2017, $202020, $17 million was included in Great Lakes'Lakes’ receivables in regardsregard to the transportation contracts with TransCanadaTC Energy and its affiliates (December 31, 20162019 – $19 million).

In 2017, Great Lakes operates under a FERC approved 2013 rate settlement that includes a revenue sharing mechanism that requires Great Lakes to share with its customers certain percentages of any qualifying revenues earned above certain ROEs. A refund of $7 million was paid to shippers in 2017 relating to the year ended December 31, 2016, of which approximately 86 percent was made to affiliates of Great Lakes. For the year ended December 31, 2017, Great Lakes has recorded an estimated revenue sharing provision amounting to $40 million and Great Lakes expects that a significant percentage of the 2017 revenue sharing refund will be to its affiliates.

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Under the terms of the 2017 Great Lakes Settlement, beginning 2018, the revenue sharing was eliminated (refer to Note 5. Additionally, effective October 1, 2017, Great Lakes still charged customers rates in effect prior to the 2017 Great Lakes Settlement but only recognized revenue up to the amount of the new rates in the 2017 Great Lakes Settlement. The difference between these two amounts was recognized as a provision for rate refund (liability) on Great Lakes' balance sheet amounting to $8 million. Great Lakes expects that a significant percentage of the provision for rate refund will be to its affiliates as well.

Great Lakes has a cash management agreement with TransCanadaTC Energy whereby Great Lakes'Lakes’ funds are pooled with other TransCanadaTC Energy affiliates. The agreement also gives Great Lakes the ability to obtain short-term borrowings to provide liquidity for Great Lakes' Lakes’
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operating needs. At December 31, 20172020 and 2016,2019, Great Lakes has anhad outstanding receivablereceivables from this arrangement amounting to $64$27 million and $27$34 million, respectively.

Effective

Great Lakes has a long-term transportation agreement with TC Energy's Canadian Mainline natural gas transmission system (Canadian Mainline) that commenced on November 1, 2014, Great Lakes executed contracts with an affiliate, ANR Pipeline Company (ANR), to provide firm service in Michigan and Wisconsin. These contracts were at the maximum FERC authorized rate and were intended to replace historical contracts. On December 3, 2014, FERC accepted and suspended Great Lakes' tariff records to become effective May 3, 2015, subject to refund. On February 2, 2015, FERC issued an Order granting a rehearing and clarification request submitted by Great Lakes, which allowed additional time for FERC to consider Great Lakes' request. Following extensive discussions with numerous shippers and other stakeholders, on April 20, 2015, ANR filed a settlement with FERC that included an agreement by ANR to pay Great Lakes the difference between the historical and maximum rates (ANR Settlement). Great Lakes provided service to ANR under multiple service agreements and rates through May 3, 2015 when Great Lakes' tariff records became effective and subject to refund. Great Lakes deferred an approximate $9 million of revenue related to services performed in 2014 and approximately $14 million of additional revenue related to services performed through May 3, 2015 under such agreements. On October 15, 2015, FERC accepted and approved the ANR Settlement. As a result, Great Lakes recognized the deferred transportation revenue of approximately $23 million in the fourth quarter of 2015.

On April 24, 2017 Great Lakes reached an agreement on the terms of a new long-term transportation capacity contract with its affiliate, TransCanada. The contract, which was subject to Canada's National Energy Board (NEB) approval, is for a term of 10 yearsten-year period and allows TransCanada the abilityTC Energy to transport up to 0.711 billion cubic feet of natural gas per day on the Great Lakes system from the Manitoba/U.S. border to the U.S. border near Dawn Ontario. On September 21, 2017, TransCanada received approval from the NEB and as a result, thissystem. This contract, commenced on November 1, 2017. This contractwhich contains volume reduction options up to full contract quantity beginning in year three.three, was a direct benefit from TC Energy’s long-term fixed price service on its Canadian Mainline that was launched in 2017. For the year ended December 31, 2017,2020, the total reservation revenue earned by Great Lakes on this contract was $13 million.

$75 million (2019 - $76 million; 2018 - $76 million). On November 20, 2020, this contract was revised. Effective November 1, 2021 the original contract rate will be reduced with no changes in the contracted volume. Additionally, after November 20, 2020, the Canadian Mainline shall have the right to reduce the contracted volume or terminate the full contract, effective November 1st of the applicable year, provided that 349 days’ prior written notice has been given to Great Lakes. As of February 24, 2021, no further changes to this contract have been made. The future revenue reduction on Great Lakes from the revised contract is not expected to have a material impact on the Partnership's expected distributions from Great Lakes.


In 2018, Great Lakes executed long-term transportation capacity contracts with its affiliate, ANR Pipeline Company (ANR) in anticipation of specific possible future needs. The original total contract value of these contracts was approximately $1.3 billion over a 15-year period. These contracts were subject to certain conditions and provisions, including a reduction option up to the full contract quantity if exercised up to a certain date. During the first quarter of 2020, several amendments were made to these contracts and ANR exercised the right to terminate a significant portion of the contracts amounting to approximately $1.1 billion. The remaining maximum rate contract, which has a total capacity of approximately 168,000 Dth/day and total contract value of $182 million over a term of 20 years, is expected to begin in late 2022. This contract, which has a full quantity reduction option at any time before October 1, 2022, is dependent on ANR being able to secure the required regulatory approvals and other requirements of the project associated with these volumes. Any remaining unsubscribed capacity on Great Lakes will be available for contracting in response to developing marketing conditions.

Northern Border
For the year ended December 31, 2020, Northern Border provided transportation service to TC Energy Marketing Inc., a subsidiary of TC Energy and earned revenues of $0.8 million in 2020 (2019 and 2018 - NaN). At December 31, 2020 and 2019, Northern Border had 0 outstanding receivables from TC Energy Marketing, Inc.
PNGTS

For the year ended December 31, 2020, PNGTS did not provide transportation services to TC Energy subsidiaries. For the years ended December 31, 2017, 20162019 and 2015,2018, PNGTS provided transportation servicesservice to a related party. Revenues from TransCanada Energy Ltd., a subsidiary of TransCanada, for 2017, 2016TC Energy and 2015 were approximatelyearned revenues of less than $1 million $2 million and $3$1 million, respectively. At December 31, 2017,2020 and 2019, PNGTS had nil million0 outstanding receivables from TransCanada Energy Ltd. in the consolidated balance sheets.


In connection with anticipated future commercial opportunities,the Portland XPress expansion project (PXP), which was designed to be phased in over a three-year time period, PNGTS has entered into an arrangement with its affiliates regarding the construction of certain facilities on their systems that will beare required to fulfill future contracts on the PNGTS'PNGTS system. In the event the anticipated developments do not proceed,expansions are terminated prior to their in-service dates, PNGTS willwould be required to reimburse its affiliates for any costs incurred related to the development of these facilities. In November 2020, the last phase of PXP (Phase III) was placed in service. As a result of December 31, 2017,placing the TC Energy facilities associated with the Phases I, II and III volumes in service, PNGTS' reimbursement obligation to TC Energy relating to this project has been extinguished.

Commercial System Purchase
On August 1, 2020, GTN, Great Lakes, Tuscarora and North Baja entered into a purchase agreement with a TC Energy affiliate to purchase an internally developed customer-facing commercial natural gas transmission IT application that maintains and manages customer contracts, natural gas capacity release, customer nominations, metering and billings. The total value of the transaction was $51 million and the Partnership's proportionate share of the cost was $38 million. Prior to the transaction close, GTN, Great Lakes, Tuscarora and North Baja paid the affiliate for the use of this system and the costs incurred by these affiliates was approximately $3 million.

TC PipeLines, LPAnnual Report2017    F-29


are included in the "Impact on Partnership's income" tabular summary above. Refer to Note 7 for additional information.

NOTE 18 QUARTERLY FINANCIAL DATA (unaudited)

The following sets forth selected unaudited financial data for the four quarters in 20172020 and 2016:


Quarter ended (millions of dollars except per common unit amounts)

 
Mar 31

 
Jun 30

 
Sept 30

 
Dec 31

 

2017         
Transmission revenues 112 101 100 109 
Equity earnings 36 24 27 37 
Net income 83 55 55 70 
Net income attributable to controlling interests 77 55 54 66 
Net income per common unit $1.05 $0.73 $0.61 $0.77 
Cash distribution paid to common units(a) 68 68 74 74 
Cash distribution paid to Class B units 22    

2016         
Transmission revenues(b) 111 101 103 111 
Equity earnings(b) 33 20 22 22 
Net income(b) 81 57 60 65 
Net income attributable to controlling interests(b) 74 55 58 61 
Net income per common unit(c) $1.10 $0.76 $0.65 $0.70 
Cash distribution paid to common unit(c) 59 60 65 66 
Cash distribution paid to Class B units 12    
2019:
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Quarter ended (millions of dollars except per common unit amounts)
Mar 31Jun 30Sept 30Dec 31
2020
Transmission revenues101 95 99 104 
Equity earnings55 29 39 47 
Net income (loss)94 61 68 78 
Net income (loss) attributable to controlling interests88 57 65 74 
Net income (loss) per common unit$1.21 $0.78 $0.90 $1.01 
Cash distributions paid to common units (a)
47 47 47 47 
Cash distribution paid to Class B units8 0 0 0 
2019
Transmission revenues113 93 93 104 

Equity earnings54 30 31 45 
Net income100 57 59 82 
Net income attributable to controlling interests93 55 56 76 
Net income per common unit$1.28 $0.75 $0.76 $0.95 
Cash distributions paid to common units (a)
47 47 47 47 
Cash distribution paid to Class B units13 
(a)
Distributions paid to common units includes our general partner's effective twopartner’s 2 percent share and IDRs.

(b)
Recast to consolidate PNGTS for the year ended December 31, 2016 (Refer to Note 2).

(c)
Historical net income per common unit was not recasted.
IDRs, if any.

NOTE 19 FAIR VALUE MEASUREMENTS

(a)Fair Value Hierarchy

Under ASC 820, Fair Value Measurements and Disclosures, fair value measurements are characterized in one of three levels based upon the input used to arrive at the measurement. The three levels of the fair value hierarchy are as follows:

Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access at the measurement date.

Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

Level 3 inputs are unobservable inputs for the asset or liability.

When appropriate, valuations are adjusted for various factors including credit considerations. Such adjustments are generally based on available market evidence. In the absence of such evidence, management'smanagement’s best estimate is used.

(b)Fair Value of Financial Instruments


The carrying value of cash"cash and cash equivalents, accounts" "accounts receivable and other, accounts" "accounts payable and accrued liabilities, accounts" "accounts payable to affiliates, accrued interestaffiliates" and short-term debt"accrued interest" approximate their fair values because of the short maturity or duration of these instruments, or because the instruments bear a variable rate of interest or a rate that approximates current rates. The fair value of the Partnership's long-termPartnership’s debt is estimated by discounting the future cash flows of each instrument at estimated current borrowing rates. The fair value of interest rate derivatives is calculated using the income approach, which uses period-end market rates and applies a discounted cash flow valuation model.


The Partnership has classified the fair value of natural gas imbalances as a Level 2 of the fair value hierarchy for fair value disclosure purposes, as the valuation approach includes quoted prices in the market index and observable volumes for the imbalance.

Long-term debt is recorded at amortized cost and classified in Level 2 of the fair value hierarchy for fair value disclosure purposes. Interest rate derivative assets and liabilities are classified in Level 2 for all periods presented where the fair value is determined by using valuation techniques that refer to observable market data or estimated market prices. The estimated fair value of the Partnership's debt as at December 31, 20172020 and December 31, 20162019 was $2,475$2,388 million and $1,963$2,111 million, respectively.

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The common units subject to rescission as presented in the December 31, 2016 balance sheet, as discussed more fully in Note 10, were measured using the original issuance price, plus statutory interest and less any distributions paid. This fair value measurement is classified as Level 2.

Market risk is the risk that changes in market interest rates may result in fluctuations in the fair values or cash flows of financial instruments. The Partnership'sPartnership’s floating rate debt is subject to LIBOR benchmark interest rate risk. The Partnership uses interest rate derivatives to manage its exposure to interest rate risk. We regularly assess the impact of interest rate fluctuations on future cash flows and evaluate hedging opportunities to mitigate our interest rate risk.

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The Partnership’s interest rate swaps mature on October 2, 2022 and are structured such that the cash flows of the derivative instruments match those of the variable rate of interest on the 2013 Term Loan Facility. The Partnership hedgedfixed weighted average interest paymentsrate on these instruments is 3.26 percent. On June 26, 2019, in conjunction with the variable-ratePartnership's $50 million repayment on its 2013 Term Loan Facility, withthe Partnership also terminated an equivalent amount in interest rate swaps maturing July 1, 2018,that were used to hedge this facility at a weighted average fixed interestan unwind rate of 2.31 percent. 2.81 percent (See also Note 8).
At December 31, 2017,2020, the fair value of the interest rate swaps accounted for as cash flow hedges was an asseta liability of $5$15 million (on both gross and net basis). At December (December 31, 2016, the fair value of the interest rate swaps accounted for as cash flow hedges was an asset of $1 million and a2019 - liability of $1 million (on a gross basis) and an asset of nil million (on a net basis). The Partnership did not record any amounts in net income related to ineffectiveness for interest rate hedges for$6 million), the years ended December 31, 2017, 2016 and 2015. The net change in fair value of interest rate derivative instrumentswhich is recognized in other comprehensive income was a gain of $5 million forincome. For the year ended December 31, 2017 (2016 – gain of $2 million, 2015 – nil). In 2017,2020, the net realized loss related to the interest rate swaps was nil,$7 million and was included in financial charges and other (2016 – $3(2019 - $1 million 2015gain, 2018 – $2 million)million gain). Refer to Note 12 – Financial Charges and Other.

As discussed in Note 8, the Partnership's $500 million 2013 Term Loan that was due July 1, 2018, was amended to extend the maturity period through October 2, 2022. As a result of this extension, the Partnership implemented an interest rate hedging strategy during the fourth quarter of 2017 and hedged the entire $500 million until its October 2, 2022 maturity using forward starting swaps at an average rate of 3.26 percent.

The Partnership has no master netting agreements,agreements; however, its contracts contain provisions with rights of offset. The Partnership has elected to present the fair value of derivative instruments with the right to offset on a gross basis in the balance sheet. Had the Partnership elected to present these instruments on a net basis, there would be net asset of $5 million as of December 31, 2017 and there would be no effect on the consolidated balance sheet as of December 31, 2016.

In anticipation of a debt refinancing in 2003, PNGTS entered into forward interest rate swap agreements to hedge the interest rate on its Senior Secured Notes due in 2018. These interest rate swaps were used to manage the impact of interest rate fluctuations2020 and qualified as derivative financial instruments in accordance with ASC 815,Derivatives and Hedging. PNGTS settled its position with a payment of $20.9 million to counterparties at the time of the refinancing and recorded the realized loss in AOCI as of the termination date. The previously recorded AOCI is currently being amortized against earnings over the life of the PNGTS Senior Secured Notes. At December 31, 2017, our 61.71 percent proportionate share of net unamortized loss on PNGTS included in AOCI was $1 million (2016 – $2 million). For the year ended December 31, 2017, 2016 and 2015, our 61.71 percent proportionate share of the amortization of realized loss on derivative instruments was $0.8 million for each year.

2019.

Our maximum counterparty credit exposure with respect to financial instruments at the balance sheet date consists primarily of the carrying amount, which approximates fair value of non-derivative financial assets, such as cash and cash equivalents and receivables, as well as the fair value of derivative financial assets. We review our accounts receivable regularly and record allowances for doubtful accounts using the specific identification method. At December 31, 2017,2020, we had not incurred any significant credit losses and had no0 significant amounts past due or impaired. At December 31, 2017, we had a credit risk concentration on one of our customers and the amount owed is greater2020, no customer accounted for more than 10 percent of our tradeconsolidated revenues and accounts receivable, respectively (refer also to Note 16)16 for more details).

PNGTS
In anticipation of a debt refinancing in 2003, PNGTS entered into forward interest rate swap agreements to hedge the interest rate on its 5.90% Senior Secured Notes due in 2018. These interest rate swaps were used to manage the impact of interest rate fluctuations and qualified as derivative financial instruments in accordance with ASC 815, Derivatives and Hedging. PNGTS settled its position with a payment of $20.9 million to counterparties at the time of the refinancing and recorded the realized loss in AOCI as of the termination date. At December 31, 2018, and as a result of the repayment of the 5.90% Senior Secured Notes, the remaining balance of the $20.9 million realized loss in AOCI included in other comprehensive income at the termination date was fully amortized against earnings. For the year ended December 31, 2018, our 61.71 percent proportionate share of the amortization of realized loss on derivative instruments was $1 million.
(c)Other

The estimated fair value measurement onmeasurements used in any of our equity investment in Great Lakes isimpairment analyses are classified as Level 3. In the determination of fair value utilized in the recoverability assessments for the respective assets, we used internal forecasts on expected future cash flows and applied appropriate discount rates. The determination of expected future cash flowsrates which involved significant assumptions and estimates as discussed more fully in Note 5.

TC PipeLines, LPAnnual Report2017    F-31


estimates.

NOTE 20 ACCOUNTS RECEIVABLE AND OTHER


December 31 (millions of dollars)
 
2017
 
2016(a)
 

Trade accounts receivable, net of allowance of nil 40 44 
Imbalance receivable from affiliates 1 2 
Other 1 1 

  42 47 

(a)
Recast to consolidate PNGTS (Refer to Notes 2 and 7).

NOTE 21    REGULATORY

GTN – GTN operates under rates established pursuant to a settlement approved by FERC in June 2015. Beginning in January 2016, GTN's rates decreased by 10 percent and will continue in effect through December 31, 2019. Unless superseded by a subsequent rate case or settlement, GTN's rates will decrease an additional eight percent for the period January 1, 2020 through December 31, 2021 when GTN will be required to establish new rates.

Tuscarora – Tuscarora operates under rates established pursuant to a settlement approved by FERC in September 2016. Under the settlement, Tuscarora's system-wide unit rate initially decreased by 17 percent, effective August 1, 2016. Unless superseded by a subsequent rate case or settlement, this rate will remain in effect until July 31, 2019, after which time the unit rate will decrease by an additional seven percent from August 1, 2019 through July 31, 2022. The settlement does not contain a rate moratorium and requires Tuscarora to file to establish new rates no later than August 1, 2022.

Bison – Bison continues to operate under the rates approved by FERC in connection with Bison's initial construction and has no requirement to file a new rate proceeding.

North Baja – North Baja continues to operate under the rates approved by FERC and has no requirement to file a new rate proceeding. On January 6, 2017, North Baja notified FERC that current market conditions do not support the replacement of the compression that was temporarily abandoned in 2013 and requested authorization to permanently abandon two compressor units and a nominal volume of unsubscribed firm capacity. FERC approved the permanent abandonment request on February 16, 2017. The requested abandonments will not have any impact on existing firm transportation service.

PNGTS – PNGTS continues to operate under the rates approved by FERC in February 2015 (Refer to Note 2 – Significant Accounting Policies – Revenue Recognition). PNGTS has no requirement to file a new rate proceeding.

NOTE 22    CONTINGENCIES

The Partnership and its pipeline systems are subject to various legal proceedings in the ordinary course of business. Our accounting for contingencies covers a variety of business activities, including contingencies for legal and environmental liabilities. The Partnership accrues for these contingencies when the assessments indicate that it is probable that a liability has been incurred or an asset will not be recovered and an amount can be reasonably estimated in accordance withASC 450 – Contingencies. We base these estimates on currently available facts and the estimates of the ultimate outcome or resolution. Actual results may differ from estimates resulting in an impact, positive or negative, on earnings and cash flow. Contingencies that might result in a gain are not accrued in our consolidated financial statements.

Below is a material legal proceeding that might have a significant impact on the Partnership:

Great Lakes v. Essar Steel Minnesota LLC, et al. – On October 29, 2009, Great Lakes filed suit in the U.S. District Court, District of Minnesota, against Essar Minnesota LLC (Essar Minnesota) and certain Foreign Essar Affiliates (collectively, Essar) for breach of its monthly payment obligation under its transportation services agreement with Great Lakes. Great Lakes sought to recover approximately $33 million for past and future payments due under the agreement. On September 16, 2015, following a jury trial, the federal district court judge entered a judgment in the amount of $32.9 million in favor of Great Lakes. On September 20, 2015, Essar appealed the decision to the United States Court of Appeals for the Eighth Circuit (Eighth Circuit) based on an allegation of improper jurisdiction and a number of other rulings by the federal district judge. Essar was required to post a performance bond for the full value of the judgment pending appeal. The Eighth Circuit heard the appeal on October 20, 2016. A decision on the appeal was received in December 2016 and the Eighth Circuit vacated Great Lakes' judgment against Essar finding that there was no federal jurisdiction. Great Lakes filed a Request for Rehearing with the Eighth Circuit and it was denied in January 2017. Before the Circuit Court issued its decision, Essar Minnesota filed for bankruptcy in July 2016. The Foreign Essar Affiliates have not filed for bankruptcy. Following the Circuit Court's decision, the performance bond was released into the bankruptcy court proceedings. Great Lakes filed a claim against Essar Minnesota in the bankruptcy court and its case against the Foreign Essar Affiliates in

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Minnesota state court remains pending. In April 2017, after Great Lakes agreement with creditors on an allowed claim, the bankruptcy court approved Great Lakes' claim in the amount of $31.5 million. On May 20, 2017, the federal district court awarded Essar Minnesota approximately $1.2 million for costs, including recovery of the performance bond premium, to be paid by Great Lakes. Great Lakes filed a motion with the bankruptcy court to offset the $1.2 million award of costs against its claim against Essar Minnesota in the bankruptcy proceeding but was unsuccessful. As a result, Great Lakes accrued the $1.2 million in its books. Great Lakes is unable to estimate the timing or the extent to which its claim will be recoverable in the bankruptcy proceedings.

NOTE 23    VARIABLE INTEREST ENTITIES

In the normal course of business, the Partnership must re-evaluate its legal entities under the current consolidation guidance to determine if those that are considered to be VIEs are appropriately consolidated or if they should be accounted for under other GAAP. A variable interest entity (VIE) is a legal entity that does not have sufficient equity at risk to finance its activities without additional subordinated financial support or is structured such that equity investors lack the ability to make significant decisions relating to the entity's operations through voting rights or do not substantively participate in the gains or losses of the entity. A VIE is appropriately consolidated if the Partnership is considered to be the primary beneficiary. The VIE's primary beneficiary is the entity that has both (1) the power to direct the activities of the VIE that most significantly impact the VIEs economic performance and (2) the obligation to absorb losses or the right to receive benefits from the VIE that could potentially be significant to the VIE.

As a result of its analysis, the Partnership continues to consolidate all legal entities in which it has a variable interest and for which it is considered to be the primary beneficiary. VIEs where the Partnership is not the primary beneficiary, but has a variable interest in the entity, are accounted for as equity investments.

Consolidated VIEs

The Partnership's consolidated VIEs consist of the Partnership's ILPs that hold interests in the Partnership's pipeline systems. After considering the purpose and design of the ILPs and the risks that they were designed to create and pass through to the Partnership, the Partnership has concluded that it is the primary beneficiary of these ILPs because of the significant amount of variability that it absorbs from the ILPs' economic performance.

The assets and liabilities held through these VIEs that are not available to creditors of the Partnership and whose investors have no recourse to the credit of the Partnership are held through GTN, Tuscarora, Northern Border, Great Lakes, PNGTS and Iroquois due to their third party debt. The following table presents the total assets and liabilities of these entities that are included in the Partnership's Consolidated Balance Sheets:


(millions of dollars)
 
December 31,
2017
 
December 31,
2016(b)
  

ASSETS (LIABILITIES)(a)      
 Cash and cash equivalents 19 14  
 Accounts receivable and other 30 33  
 Inventories 6 6  
 Other current assets 5 6  
 Equity investments 1,213 918  
 Plant, property and equipment 1,133 1,146  
 Other assets 1 2  
 Accounts payable and accrued liabilities (24)(21) 
 Accounts payable to affiliates, net (42)(32) 
 Distributions payable (1)(3) 
 Accrued interest (2)(2) 
 Current portion of long-term debt (51)(52) 
 Long-term debt (308)(337) 
 Other liabilities (26)(25) 
 Deferred state income tax (10)(10) 

(a)
North Baja and Bison, which are also assets held through our consolidated VIEs, are excluded as the assets of these entities can be used for purposes other than the settlement of the VIE's obligations.

(b)
Recast to consolidate PNGTS for the year ended December 31, 2016 (Refer to Note 2).

TC PipeLines, LPAnnual Report2017    F-33


NOTE 24    INCOME TAXES

The state of New Hampshire (NH) imposes a business profits tax (BPT) levied at the PNGTS level. As a result of the BPT, PNGTS recognizes deferred taxes related to temporary differences between the financial statement carrying amount of existing assets and liabilities and their respective tax bases. The deferred taxes at December 31, 2017, 2016 and 2015 relate primarily to utility plant. For the years ended December 31, 2017, 2016 and 2015, the NH BPT effective tax rate was 3.8 percent for all periods and was applied to PNGTS' taxable income.

The state income taxes of PNGTS are broken out as follows:


Year ended December 31 (millions of dollars)
 
2017
 
2016(a)
 
2015(a)  
  

State income taxes        
 Current 1 1 (2) 
 Deferred   4  

  1 1 2  

(a)
Recast to consolidate PNGTS (Refer to Notes 2 and 7).
December 31 (millions of dollars)
20202019
Trade accounts receivable, net of immaterial allowance for doubtful accounts36 37 
Receivable from affiliates1 
Other3 
40 43 

NOTE 2521 SUBSEQUENT EVENTS

Management of the Partnership has reviewed subsequent events through February 26, 2018,24, 2021, the date the financial statements were issued, and concluded there were no events or transactions during this period that would require recognition or disclosure in the consolidated financial statements other than what is disclosed here and/or those already disclosed in the preceding notes.

Partnership

On January 23, 2018,19, 2021, the board of directors of our General Partner declared the Partnership's fourth quarter 20172020 cash distribution in the amount of $1.00$0.65 per common unit and was paid on February 13, 201812, 2021 to unitholders of record as of February 2, 2018.January 29, 2021. The declared distribution totaled $76$47 million and was paidis payable in the following manner: $71$46 million to common unitholders (including $6$4 million to the General Partner as a holder of 5,797,106 common units and $11$7 million to another subsidiary of TransCanadaTC Energy as holder of 11,287,725 common units) and $5$1 million to ourthe General Partner which included $2 million for its effective two2 percent general partner interest and $3 million of IDRs payment.

On January 23, 2018, the board of directors of ourinterest. The General Partner declareddid 0t receive any distributions to Class B unitholders in respect of its IDRs for the amountfourth quarter 2020.

TC PipeLines, LP Annual Report 2020F-29

Table of $15 million which was paid on February 13, 2018. The Class B distribution represents an amount equal to 30 percent of GTN's distributable cash flow during the year ended December 31, 2017 less $20 million.

Contents

Northern Border

Northern Border declared its December 20172020 distribution of $15$16 million on January 8, 2018,15, 2021, of which the Partnership received its 50 percent share or $7$8 million on January 31, 2018.

29, 2021.

Northern Border declared its January 20182021 distribution of $17$18 million on February 14, 2018,16, 2021, of which the Partnership will receive its 50 percent share or $9 million on February 28, 2018.

26, 2021.

Great Lakes

Great Lakes declared its fourth quarter 20172020 distribution of $20$23 million on January 10, 2018,13, 2021, of which the Partnership received its 46.45 percent share or $9$11 million on February 1, 2018.

January 29, 2021.

Iroquois

Iroquois declared its fourth quarter 20172020 distribution of $29$22 million on January 22, 2018, of whichFebruary 18, 2021, and the Partnership receivedwill receive its 49.34 percent share or $14$11 million on February 1, 2018. The $14March 24, 2021. Additionally, on March 24, 2021, the Partnership will make a $1 million includes our proportionatecapital contribution to Iroquois representing the Partnership's 49.34 percent share of Iroquois' unrestricteda cash amountingcall from Iroquois to $2.6cover costs related to their ExC Project.
PNGTS
PNGTS declared its fourth quarter 2020 distribution of $12 million (referon January 13, 2021, of which $5 million was paid to Note 7).

PNGTS

its non-controlling interest owner on January 29, 2021.


TC PipeLines, LP
The Partnership's $350 million aggregate principal amount of 4.65 percent Unsecured Senior Notes mature on June 15, 2021. On January 2, 2018, PNGTS paidFebruary 12, 2021, the amount duePartnership exercised its option to redeem the Unsecured Senior Notes on December 31, 2017 on its 2003 Senior Secured Notes amountingMarch 15, 2021, at a redemption price equal to $6 million representing $6 million in principal and nil in interest pursuant to the terms100% of the Note Purchase agreement. Underprincipal amount of the agreement, any principalnotes then outstanding, plus unpaid interest accrued to March 15, 2021. Partial funding for the redemption is expected to be provided using cash on hand, and interest that is due on a date other than a normal business day shall be made onborrowings under the next succeeding business day without additional interest or penalty.

F-34Partnership’s $500 million Senior Credit Facility.

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 2020

Table of Contents

NORTHERN BORDER PIPELINE COMPANY
INDEPENDENT AUDITORS' REPORT



The Management Committee
Northern Border Pipeline Company:

Report on the Financial Statements


We have audited the accompanying financial statements of Northern Border Pipeline Company, (the Company), which comprise the balance sheets as of December 31, 20172020 and 2016,2019, and the related statements of income, comprehensive income, changes in partners'partners’ equity, and cash flows for each of the years in the three-year period ended December 31, 2017,2020, and the related notes to the financial statements.

Management's


Management’s Responsibility for the Financial Statements

Management is responsible for the preparation and fair presentation of these financial statements in accordance with U.S. generally accepted accounting principles; this includes the design, implementation, and maintenance of internal control relevant to the preparation and fair presentation of financial statements that are free from material misstatement, whether due to fraud or error.

Auditors'


Auditors’ Responsibility

Our responsibility is to express an opinion on these financial statements based on our audits.We conducted our audits in accordance with auditing standards generally accepted in the United States of America. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free from material misstatement.


An audit involves performing procedures to obtain audit evidence about the amounts and disclosures in the financial statements. The procedures selected depend on the auditors'auditors’ judgment, including the assessment of the risks of material misstatement of the financial statements, whether due to fraud or error. In making those risk assessments, the auditor considers internal control relevant to the entity'sentity’s preparation and fair presentation of the financial statements in order to design audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the entity'sentity’s internal control. Accordingly, we express no such opinion. An audit also includes evaluating the appropriateness of accounting policies used and the reasonableness of significant accounting estimates made by management, as well as evaluating the overall presentation of the financial statements.


We believe that the audit evidence we have obtained is sufficient and appropriate to provide a basis for our audit opinion.


Opinion

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of Northern Border Pipeline Company as of December 31, 20172020 and 2016,2019, and the results of its operations and its cash flows for each of the years in the three-year period ended December 31, 2017,2020 in accordance with U.S. generally accepted accounting principles.



/s/ KPMG LLP

Houston, Texas
February 16, 2018

19, 2021

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Table of Contents


NORTHERN BORDER PIPELINE COMPANY
BALANCE SHEETS


December 31, 2017 and 2016 (In thousands)
 
2017
 
2016
  

Assets      
Current assets:      
 Cash and cash equivalents $      14,010 13,535  
 Accounts receivable 24,738 23,484  
 Related party receivables 3,049 3,503  
 Materials and supplies 5,216 5,727  
 Prepaid expenses and other 3,761 3,482  

  Total current assets 50,774 49,731  

Property, plant and equipment:      
 In service natural gas transmission plant 2,605,625 2,584,065  
 Construction work in progress 5,692 1,409  

 Total property, plant and equipment 2,611,317 2,585,474  
 Less: Accumulated provision for depreciation and amortization 1,548,635 1,496,860  

  Property, plant and equipment, net 1,062,682 1,088,614  

Other assets:      
 Regulatory assets 13,994 14,773  
 Other 7 7  

  Total other assets 14,001 14,780  

   Total assets $1,127,457 1,153,125  


Liabilities and Partners' Equity

 

 

 

 

 

 
Current liabilities:      
 Accounts payable $        9,737 9,568  
 Related party payables 4,154 3,507  
 Accrued taxes other than income 19,609 20,286  
 Accrued interest 4,691 4,707  
 Other 243 196  

  Total current liabilities 38,434 38,264  

Long-term debt, net 264,056 429,545  
Deferred credits and other liabilities      
 Regulatory liabilities 27,031 24,473  
 Other 4,336 3,931  

  Total deferred credits and other liabilities 31,367 28,404  

   Total liabilities 333,857 496,213  

Partners' equity:      
 Partners' capital 794,869 658,466  
 Accumulated other comprehensive loss (1,269)(1,554) 

  Total partners' equity 793,600 656,912  

   Total liabilities and partners' equity $1,127,457 1,153,125  

December 31, 2020 and 2019 (in thousands)20202019
Assets
Current assets:
Cash and cash equivalents$31,174 20,667 
Accounts receivable23,180 24,418 
Related party receivables4,877 4,391 
Materials and supplies6,472 5,706 
Prepaid expenses and other3,483 2,783 
Total current assets69,186 57,965 
Property, plant and equipment:
In-service natural gas transmission plant2,668,642 2,633,800 
Construction work in progress9,308 1,601 
Right of use asset133 156 
Total property, plant and equipment2,678,083 2,635,557 
Less: Accumulated provision for depreciation and amortization1,701,463 1,646,711 
Property, plant and equipment, net976,620 988,846 
Other assets:
Regulatory assets11,657 12,436 
Other221 — 
11,878 12,436 
Total assets$1,057,684 $1,059,247 
Liabilities and Partners' Equity
Current liabilities:
Accounts payable$10,899 3,663 
Related party payables4,198 4,421 
Accrued taxes other than income18,811 18,369 
Accrued interest4,831 4,986 
Customer advances for construction13,404 10,517 
Other current liabilities23 22 
Current maturities of long-term debt250,000 — 
Total current liabilities302,166 41,978 
Long-term debt, net129,769 364,352 
Deferred credits and other liabilities
Regulatory liability36,115 33,219 
Other5,659 5,280 
Total deferred credits and other liabilities41,774 38,499 
Total liabilities473,709 444,829 
Partners' equity:
Partners' capital584,255 615,052 
Accumulated other comprehensive loss(280)(634)
Total partners' equity583,975 614,418 
Total liabilities and partners' equity$1,057,684 1,059,247 
The accompanying notes are an integral part of these financial statements.

F-36

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 2020

Table of Contents

NORTHERN BORDER PIPELINE COMPANY
STATEMENTS OF INCOME


Years ended December 31, 2017, 2016, and 2015 (In thousands)
 
2017
 
2016
 
2015
  

Operating revenue $291,396 291,642 285,510  

Operating expenses:        
 Operations and maintenance 54,374 47,652 47,260  
 Depreciation and amortization 59,426 58,813 59,571  
 Taxes other than income 23,480 24,200 22,826  

  Operating expenses 137,280 130,665 129,657  

Operating income 154,116 160,977 155,853  

Interest expense:        
 Interest expense 22,257 25,433 26,591  
 Interest expense capitalized (176)(100)(76) 

  Interest expense, net 22,081 25,333 26,515  

Other income (expense):        
 Allowance for equity funds used during construction 573 297 243  
 Other income 3,936 4,151 4,722  
 Other expense (238)(113)(420) 

  Other income, net 4,271 4,335 4,545  

Net income to partners $136,306 139,979 133,883  

NORTHERN BORDER PIPELINE COMPANY
STATEMENTS OF COMPREHENSIVE INCOME


Years ended December 31, 2017, 2016, and 2015 (In thousands)
 
2017
 
2016
 
2015
 

Net income to partners $136,306 139,979 133,883 
Other comprehensive income:       
 Changes associated with hedging transactions 285 264 245 

Total comprehensive income $136,591 140,243 134,128 

December 31, 2020, 2019, and 2018 (in thousands)202020192018
Operating revenue$307,803 300,221 289,418 
Operating expenses:
Operations and maintenance54,215 60,428 54,576 
Depreciation and amortization62,109 61,588 60,492 
Taxes other than income23,098 22,539 23,892 
Operating expenses139,422 144,555 138,960 
Operating income168,381 155,666 150,458 
Interest expense:
Interest expense21,766 21,727 19,943 
Interest expense capitalized(195)(37)(101)
Interest expense, net21,571 21,690 19,842 
Other income (expense):
Allowance for equity funds used during construction1,169 318 623 
Other income2,918 3,805 4,505 
Other expense(79)(357)(37)
Other income, net4,008 3,766 5,091 
Net income to partners$150,818 137,742 135,707 
The accompanying notes are an integral part of these financial statements.

TC PipeLines, LPAnnual Report2017    F-37

2020F-33

Table of Contents


NORTHERN BORDER PIPELINE COMPANY
STATEMENTS OF CASH FLOWS

Years ended December 31, 2017, 2016, and 2015 (In thousands)
 
2017
 
2016

 
2015

  

Cash flows from operating activities:         
 Net income to partners $136,306 139,979 133,883  

 Adjustments to reconcile net income to partners to net cash provided by operating activities:         
  Depreciation and amortization  59,426 58,813 59,571  
  Allowance for equity funds used during construction  (573)(297)(243) 
  Changes in components of working capital  (1,411)217 (7,644) 
  Other  406 45 1,843  

   Total adjustments  57,848 58,778 53,527  

    Net cash provided by operating activities  194,154 198,757 187,410  

Cash flows used in investing activities:         
 Capital expenditures  (27,054)(21,592)(15,348) 
 Other  (722)(982)(3,417) 

    Net cash used in investing activities  (27,776)(22,574)(18,765) 

Cash flows used in financing activities:         
 Equity contributions from partners  166,000    
 Distributions to partners  (165,903)(209,792)(182,173) 
 Proceeds from issuance of debt   128,000 10,000  
 Repayment of debt  (166,000)(108,000)(10,000) 
 Debt issuance costs   (150)(564) 

    Net cash used in financing activities  (165,903)(189,942)(182,737) 

Net change in cash and cash equivalents  475 (13,759)(14,092) 
Cash and cash equivalents at beginning of year  13,535 27,294 41,386  

Cash and cash equivalents at end of year $14,010 13,535 27,294  

Supplemental disclosure for cash flow information:         
 Cash paid for interest, net of amount capitalized $21,301 26,746 25,802  
 Accruals for property, plant and equipment  2,592 63 1,841  

Changes in components of working capital:         
 Accounts receivable $(1,254)(973)1,220  
 Related party receivables  454 (1,163)(742) 
 Materials and supplies  511 (78)(109) 
 Prepaid expenses and other  319 374 (118) 
 Accounts payable  (1,702)3,369 (1,183) 
 Related party payables  709 318 (6,507) 
 Accrued taxes other than income  (676)520 (188) 
 Accrued interest  (15)(2,150)(17) 
 Other current liabilities  243    

   Total $(1,411)217 (7,644) 

COMPREHENSIVE INCOME

December 31, 2020, 2019, and 2018 (in thousands)202020192018
Net income to partners$150,818 137,742 135,707 
Other comprehensive income:
Changes associated with hedging transactions354 329 306 
Total comprehensive income$151,172 138,071 136,013 
The accompanying notes are an integral part of these financial statements.

F-38

F-34     TC PipeLines, LPAnnual Report2017

 2020

Table of Contents


NORTHERN BORDER PIPELINE COMPANY
STATEMENTS OF CHANGES IN PARTNERS' EQUITY

(In thousands)
 
TC PipeLines
Intermediate
Limited
Partnership

 
ONEOK
Partners
Intermediate
Limited
Partnership

 
Accumulated
Other
Comprehensive
Income (Loss)

 
Total
Partners'
Equity

  

Partners' equity at December 31, 2014 $  388,284 388,285 (2,063)774,506  
 Net income to partners 66,941 66,942  133,883  
 Changes associated with hedging transactions   245 245  
 Distributions to partners (91,086)(91,087) (182,173) 

Partners' equity at December 31, 2015 $  364,139 364,140 (1,818)726,461  
 Net income to partners 69,990 69,989  139,979  
 Changes associated with hedging transactions   264 264  
 Distributions to partners (104,896)(104,896) (209,792) 

Partners' equity at December 31, 2016 $  329,233 329,233 (1,554)656,912  
 Net income to partners 68,153 68,153  136,306  
 Changes associated with hedging transactions   285 285  
 Contributions from partners 83,000 83,000  166,000  
 Distributions to partners (82,952)(82,951) (165,903) 

Partners' equity at December 31, 2017 $  397,434 397,435 (1,269)793,600  

CASH FLOWS

Years ended December 31, 2020, 2019, and 2018 (In thousands)202020192018
Cash flows from operating activities:
Net income to partners$150,818 137,742 135,707 
Adjustments to reconcile net income to partners to net cash provided by operating activities:
Depreciation and amortization62,109 61,588 60,492 
Allowance for equity funds used during construction(1,169)(318)(623)
Changes in components of working capital4,800 578 (5,909)
Amortization of debt expense871 226 704 
Other(208)1,708 2,208 
Total adjustments66,403 63,782 56,872 
Net cash provided by operating activities217,221 201,524 192,579 
Cash flows used in investing activities:
Capital expenditures(42,886)(11,344)(31,269)
Other2,887 7,787 646 
Net cash used in investing activities(39,999)(3,557)(30,623)
Cash flows used in financing activities:
Distributions to partners(181,615)(286,899)(166,367)
Proceeds from issuance of debt14,900 100,000 — 
Net cash used in financing activities(166,715)(186,899)(166,367)
Net change in cash and cash equivalents10,507 11,068 (4,411)
Cash and cash equivalents at beginning of year20,667 9,599 14,010 
Cash and cash equivalents at end of year$31,174 20,667 9,599 
Supplemental disclosure for cash flow information:
Cash paid for interest, net of amount capitalized$20,827 20,687 19,098 
Accruals for property, plant and equipment, net2,462 (625)(1,113)
Changes in components of working capital:
Accounts receivable$1,238 1,223 (903)
Related party receivables(486)(1,120)(222)
Materials and supplies(766)(94)(396)
Prepaid expenses and other(24)(699)(167)
Accounts payable4,774 1,209 (5,834)
Related party payables(223)741 2,119 
Accrued taxes other than income442 (937)(303)
Accrued interest(155)255 40 
Other current liabilities — (243)
Total$4,800 578 (5,909)
The accompanying notes are an integral part of these financial statements.

TC PipeLines, LPAnnual Report2017    F-39

2020F-35

Table of Contents


NORTHERN BORDER PIPELINE COMPANY
Statements of Changes in Partners' Equity
(In thousands)TC PipeLines,
LP
ONEOK
Northern
Border
Pipeline
Company
Holdings,
L.L.C.
Accumulated
Other
Comprehensive
Income (Loss)
Total
Partners'
Equity
Partners' equity at December 31, 2017$397,434 397,435 (1,269)793,600 
Net income to partners67,854 67,853 — 135,707 
Changes associated with hedging transactions— — 306 306 
Distributions to partners(83,184)(83,183)— (166,367)
Partners' equity at December 31, 2018$382,104 382,105 (963)763,246 
Net income to partners68,871 68,871 — 137,742 
Changes associated with hedging transactions— — 329 329 
Distributions to partners(143,449)(143,450)— (286,899)
Partners' equity at December 31, 2019$307,526 307,526 (634)614,418 
Net income to partners75,409 75,409 — 150,818 
Changes associated with hedging transactions— — 354 354 
Distributions to partners(90,808)(90,807)— (181,615)
Partners' equity at December 31, 2020$292,127 292,128 (280)583,975 
The accompanying notes are an integral part of these financial statements.
F-36     TC PipeLines, LP Annual Report 2020


NORTHERN BORDER PIPELINE COMPANY
NOTES TO FINANCIAL STATEMENTS
YEARS ENDED DECEMBER
Years ended December 31, 2017 AND 2016

2020 and 2019


1. DESCRIPTION OF BUSINESS

Northern Border Pipeline Company (the Partnership) is a Texas general partnership formed in 1978. The Partnership owns a 1,263-mile natural gas transmission pipeline system, which includes an additional 149 pipeline miles parallel to the original system, extending from the United States-Canadian border near Port of Morgan, Montana, to a terminus near North Hayden, Indiana. The partners and ownership percentages at December 31, 2017 and 2016 were as follows:

Partner

Ownership



ONEOK Partners Intermediate Limited Partnership (ONEOK)50%Ownership
ONEOK Northern Border Pipeline Company Holdings, L.L.C.50 %
TC PipeLines, Intermediate Limited Partnership (TC PipeLines)LP50 50%%


TC PipeLines, LP (TCP) is an indirect subsidiary of TC Energy Corporation (TC Energy). ONEOK Northern Border Pipeline Company Holdings, L.L.C. (ONEOK) is an indirect subsidiary of ONEOK, Inc.
The Partnership is managed by a Management Committee that consists of four members. Each partner designates two members and TC PipeLinesTCP designates one of its members as chairman.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

(a)Basis of Presentation
The Partnership’s financial statements have been prepared by management in accordance with U.S. generally accepted accounting principles (GAAP). Certain prior year amounts have been reclassified to conform to the current year presentation.
(b)Use of Estimates

The preparation of the financial statements in accordance with U.S. generally accepted accounting principles (GAAP)GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses as well as the disclosure of contingent assets and liabilities during the reported period. Although management believes these estimates are reasonable, actual results could differ from these estimates in the financial statements and accompanying notes.

(b)     Judgment is required in developing these estimates.

(c)Cash and Cash Equivalents

The Partnership'sPartnership’s cash and cash equivalents consist of cash and highly liquid short-term investments with original maturities of three months or less and are recorded at cost, which approximates fair value.

(c)    

(d)Trade Accounts Receivable

Trade accounts receivable are recorded at the invoiced amount and do not bear interest, except for those receivables subject to late charges. The Partnership maintains an allowance for doubtful accounts for estimated losses on accounts receivable, if it is determined the Partnership will not collect all or part of the outstanding receivable balance. The Partnership regularly reviews its allowance for doubtful accounts and establishes or adjusts the allowance as necessary using the specific-identification method. Account balances are charged to the allowance after all means of collection have been exhausted and the potential for recovery is no longer considered probable. Accounts written off in 20172020 and 20162019 were not material to the Partnership'sPartnership’s financial statements.

(d)    

(e)Natural Gas Imbalances

Natural gas imbalances occur when the actual amount of natural gas delivered to or received from a pipeline system differs from the amount of natural gas scheduled to be delivered or received. The Partnership values these imbalances due to or from shippers and interconnecting parties at current index prices. Imbalances are settled in-kind, subject to the terms of the Partnership'sPartnership’s tariff.

Imbalances due from others are reported on the balance sheets as trade accounts receivable and related party receivables. Imbalances owed to others are reported on the balance sheets as trade accounts payable and accounts payable to affiliates.related party payables. In addition, the Partnership classifies all imbalances as current as the Partnership expects to settle them within a year.

(e)    

(f)Material and Supplies

The Partnership'sPartnership’s inventories primarily consist of materials and supplies and are carried at lower of weighted average cost or market.

F-40    and net realizable value.

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Table of Contents

(f)    

(g)Accounting for Regulated Operations

The Partnership'sPartnership’s natural gas pipeline is subject to the jurisdiction of the Federal Energy Regulatory Commission (FERC) under the Natural Gas Act of 1938 and the Natural Gas Policy Act of 1978. Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 980,Regulated Operations, provides that rate regulated enterprises account for and report assets and liabilities consistent with the economic effect of the way in which regulators establish rates, if the rates are designed to recover the costs of providing the regulated service and if the competitive environment makes it probable that such rates can be charged and collected. The Partnership evaluates the continued applicability of regulatory accounting, considering such factors as regulatory charges, the impact of competition, and the ability to recover regulatory assets as set forth in ASC 980. Accordingly, certain assets and liabilities that result from the regulated ratemaking process are reflected on the balance sheets as regulatory assets and regulatory liabilities.

The following table presents regulatory assets and liabilities at December 31, 20172020 and 2016:

 
 December 31,


  
  
 
 
Remaining
recovery/
settlement
period

  
 
 
2017

 
2016

  

   (In thousands) (Years)  
Regulatory Assets         
Fort Peck lease option $12,149 12,466 38  
Pipeline extension project  1,845 2,307 4  
Volumetric fuel tracker  1,161 1,387 (a) 
Compressor usage surcharge  823  (b) 

   15,978 16,160    
Less: Current portion included in Prepaid expenses and other  1,984 1,387    

  $13,994 14,773    

Regulatory Liabilities         
Negative salvage $27,031 24,473 (c) 
Compressor usage surcharge   196 (b) 

   27,031 24,669    
Less: Current portion included in Other   196    

  $27,031 24,473    

2019:
December 31,Remaining
recovery/
settlement
20202019period
(In thousands)(Years)
Regulatory Assets
Fort Peck right-of-way option$11,196 11,513 35
Pipeline extension project461 923 1
Volumetric fuel tracker816 139 (a)
12,473 12,575 
Less: Current portion included in Prepaid expenses and other816 139 
$11,657 12,436 
Regulatory Liabilities
Negative salvage$34,575 31,966 (c)
Compressor usage surcharge1,540 1,253 (b)
$36,115 33,219 
(a)
Volumetric fuel tracker assets or liabilities are continuously settled with in-kind exchanges with customers continually

(b)
Compressor usage surcharge is designed to track the recovery of the actual costs related to both electricity usage at the Partnership'sPartnership’s electric compressors and compressor fuel use taxes imposed on the consumption of natural gas powered stations along the Partnership'sPartnership’s pipeline system (refer to Note 5(b)4(b))

(c)
Negative salvage accrued for estimated net costs of removal of transmission plant has a settlement period related to the estimated life of the assets (refer to Note 2(g)2(h))

(g)    


(h)Property, Plant and Equipment

Property, plant and equipment are recorded at their original cost of construction. For assets the Partnership constructs, direct costs, such as labor and materials, and indirect costs, such as overhead, interest, and an equity return component on regulated businesses as allowed by the FERC, are capitalized. The Partnership capitalizes major units of property replacements or improvements and expenses minor items.

The Partnership uses the composite (group) method to depreciate property, plant and equipment. Under this method, assets with similar lives and characteristics are grouped and depreciated as one asset. The depreciation rate is applied to the total cost of the group until its net book value equals its salvage value. All asset groups are depreciated using depreciation rates approved in the Partnership'sPartnership’s last rate proceeding. Currently, the Partnership'sPartnership’s depreciation rates vary from 2% to 20% per year. Using these rates, the remaining depreciable life of these assets ranges from 1 to 3738 years.

The Partnership collects estimated future removal costs related to its transmission and gathering facilities in its current rates (also known as “negative salvage”) and recognizes a regulatory liability in this respect in the balance sheets.
Estimated costs associated with the future removal of transmission and gathering facilities are collected through depreciation as allowed by FERC. These amounts do not represent asset retirement obligations as defined by ASC 410, Accounting for Asset Retirement Obligations. When property, plant and equipment are retired, the Partnership charges accumulated depreciation and amortization for the original cost of the assets in addition to the cost to remove, sell, or dispose of the assets, less their salvage value. The Partnership does not recognize a gain or loss unless an entire operating unit is sold or retired. The Partnership includes gains or losses on dispositions of operating units in income.

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The Partnership capitalizes a carrying cost on funds invested in the construction of long-lived assets. This carrying cost includes a return on the investment financed by debt and equity allowance for funds used during construction (AFUDC). AFUDC is calculated
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recorded based on the Partnership'sPartnership’s average cost of debt and equity. Capitalized carrying costs for AFUDC debt and equity are reflected as an increase in the cost of the asset on the balance sheets.

(h)    

Capitalized AFUDC debt amounts are included as a reduction of interest and debt expense in the statements of income. Capitalized AFUDC equity amounts are included as other income in the statements of income. Debt amounts capitalized during the years ended December 31, 2020, 2019 and 2018 were $0.2 million, nil and $0.1 million, respectively. Equity amounts capitalized during the years ended December 31, 2020, 2019 and 2018 were $1.2 million, $0.3 million and $0.6 respectively. Amounts included in construction work in progress are not amortized until transferred into service.
(i)Long-Lived Assets

Long-lived assets, such as property, plant and equipment, and purchased intangible assets subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group be tested for possible impairment, the Partnership first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying value exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values, and third-party independent appraisals, as considered necessary.

(i)    

(j)Revenue Recognition

The Partnership'sPartnership’s revenues are primarily generated from contractual arrangements for committed capacity and from transportation services.of natural gas which are treated as a bundled performance obligation. Revenues for all services are based on the quantity of gas delivered or subscribed at a price specified in the contract. For the Partnership's transportation services, reservation revenues are recognized onearned from firm contracted capacity arrangements are recognized ratably over the term of the contract period regardless of the amount of natural gas that is transported. For the Partnership'sTransportation revenues for interruptible or volumetric-based services are recognized when the Partnership records revenues when physical deliveries of natural gas are made at the agreed-upon delivery point.service is performed. The Partnership doesutilizes the practical expedient of recognizing revenue as invoiced. Revenues are invoiced and paid on a monthly basis. The Partnership’s pipeline systems do not take ownership of the natural gas that it transports. is transported for customers. Revenues from contracts with customers are recognized net of any taxes collected from customers, which are subsequently remitted to governmental authorities.
The Partnership isPartnership's pipeline systems are subject to FERC regulations and, as a result, a portion of revenues the Partnership collectscollected may be subject to refund inif invoiced during an interim period when a rate proceeding. The Partnership establishes provisionproceeding is ongoing. Allowances for these potential refunds.refunds are recognized using management's best estimate based on the facts and circumstances of the proceeding. Any allowances that are recognized during the proceeding process are refunded or retained, as applicable, at the time a regulatory decision becomes final. As of December 31, 20172020, and 2016,2019, there are no refund provisions reflected in these financial statements.

(j)    

(k)Asset Retirement Obligations

The Partnership accounts for asset retirement obligations pursuant to the provisions of ASC 410-20,Asset Retirement Obligations. ASC 410-20 requires the Partnership to record the fair value of an asset retirement obligation as a liability in the period in which it incurs a legal obligation associated with the retirement of tangible long lived assets that result from the acquisition, construction, development, and/or normal use of the assets. ASC 410-20 also requires the Partnership to record a corresponding asset that is depreciated over the life of the asset. Subsequent to the initial measurement of the asset retirement obligation, the obligation is to be adjusted at the end of each period to reflect the passage of time and changes in the estimated future cash flows underlying the obligation.

The fair value of a liability for an asset retirement obligation is recorded during the period in which the liability is incurred, if a reasonable estimate of fair value can be made. The Partnership has determined that asset retirement obligations exist for certain of its transmission assets; however, the fair value of the obligations cannot be determined because the end of the transmission systemsystem’s life is not determinable with the degree of accuracy necessary to currently establish a liability for the obligations.

The Partnership has determined it has legal obligations associated with its natural gas pipelines and related transmission facilities. The obligations relate primarily to purging and sealing the pipelines if they are abandoned. The Partnership is also required to operate and maintain its natural gas pipeline system and intends to do so as long as supply and demand for natural gas exists, which the Partnership expects for the foreseeable future. Therefore, the Partnership believes its natural gas pipeline system assets have indeterminate lives and, accordingly, has recorded no asset retirement obligation as of December 31, 20172020 and 2016.2019. The Partnership continues to evaluate its asset retirement obligations and future developments that could impact amounts it records.

(k)    

(l)Derivative Instruments and Hedging Activities

The Partnership recognizes all derivative instruments as either assets or liabilities in the balance sheet at their respective fair values. For derivatives designated in hedging relationships, changes in the fair value are either offset through earnings against the change in fair value of the hedged item attributable to the risk being hedged or recognized in accumulated other comprehensive income, to the extent the derivative is effective at offsetting the changes in cash flows being hedged until the hedged item affects earnings.

The Partnership only enters into derivative contracts that it intends to designate as a hedge of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge). For all hedging relationships, the Partnership formally documents the hedging relationship and its risk-management objective and strategy for undertaking the hedge, the hedging instrument, the hedged transaction, the nature of the risk being hedged, how the hedging instrument's effectiveness in offsetting the hedged risk will be assessed prospectively and retrospectively, and a description of the method used to measure ineffectiveness. The Partnership also formally assesses, both at the inception of the hedging relationship and on an ongoing basis, whether the derivatives that are used in the

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hedging relationships are highly effective in offsetting changes in cash flows of hedged transactions. For derivative instruments that are designated and qualify as part ofIn a cash flow hedging relationship, the effective portionchange in the fair value of the gain or loss on the derivativeshedging derivative is reported as a component of other comprehensive income and reclassified into earnings as part of “interest expense” in the same period or periods during which the hedged transaction

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affects earnings. Gains and losses onearnings or is reclassified immediately to net income when the derivative representing either hedge ineffectivenesshedged item is sold or hedge components excluded from the assessment of effectiveness are recognized in current earnings.

The Partnership discontinues hedge accounting prospectivelyterminated early, or when it determinesbecomes probable that the derivative is no longer effective in offsetting cash flows attributable to the hedged risk, the derivative expires or is sold, terminated, or exercised, the cash flow hedge is de-designated because a forecasted transaction is not probable of occurring, or management determines to remove the designation of the cash flow hedge.

In all situations in which hedge accounting is discontinued and the derivative remains outstanding, the Partnership continues to carry the derivative at its fair value on the balance sheet and recognizes any subsequent changes in its fair value in earnings. When it is probable that a forecastedanticipated transaction will not occur,occur.

In some instances, the derivatives do not meet the specific criteria for hedge accounting treatment. In these instances, the changes in fair value are recorded in net income in the period of change.
Prior to December 31, 2001, the Partnership discontinues hedge accounting and recognizes immediatelyterminated a series of interest rate derivatives in earnings gains and losses that wereexchange for cash. These derivatives had previously been accounted for as hedges with $4.1 million recorded in accumulated in other comprehensive incomeloss (AOCL) as of the termination date. The previously recorded AOCL is currently being reclassified to “interest expense’ using the effective interest method over the remaining term of the related hedged instrument, the Partnership’s 2001 Senior Notes due 2021. At December 31, 2020, the remaining balance in AOCL that is left to be reclassified to earnings is $0.3 million, of which all is expected to be reclassified in 2021.
The Partnership had no other derivative instruments during the hedging relationship.

(l)    year ended December 31, 2020.

(m)Debt Issuance Costs

Costs related to the issuance of debt are deferred and amortized using the effective-interest rate method over the term of the related debt.

The Partnership amortizes premiums and discounts incurred in connection with the issuance of debt consistent with the terms of the respective debt instrument.

Debt issuance costs are presented in the balance sheet as a direct deduction from the carrying amount of debt liabilities, consistent with debt discount or premiums.discounts. In addition, amortization of debt issuance costs, premiums, and discounts are reported as part of interest expense.

(m)    Contingencies

The Partnership recognizes liabilities for contingencies when it has an exposure that, when fully analyzed, indicates it is both probable that a liability has been incurred and the amount of loss can be reasonably estimated. Where the most likely outcome of a contingency can be reasonably estimated, the Partnership accrues a liability for that amount. Where the most likely outcome cannot be estimated, a range of potential losses is established and if no one amount in that range is more likely than any other, the lower end of the range is accrued.

(n)    Commitments

The Partnership has non-cancelable leases for office space and rights-of-way commitments. The Partnership records expenses straight-line over the life of the of these arrangements.

(o)    Income Taxes

Income taxes are the responsibility of the partners and are not reflected in these financial statements.

(p)    

(o)Fair Value Measurements

For cash and cash equivalents, receivables, accounts payable and certain accrued expenses, the carrying amount approximates fair value due to the short maturities of these instruments. For long-term debt instruments, fair value is estimated based upon market values (if applicable) or on the current interest rates available to the Partnership for debt with similar terms and remaining maturities. Considerable judgmentJudgment is required in developing these estimates.


3. ACCOUNTING CHANGES

(a)    

Changes in Accounting Policies for 2017

Inventory

effective January 1, 2020


Measurement of Credit Losses on Financial Instruments
In July 2015,June 2016, the FASB issued new guidance on simplifying the measurement of inventory.that significantly changes how entities measure credit losses for most financial assets and certain other financial instruments that are not measured at fair value through net income. The new guidance specifies thatamends the impairment model of financial instruments basing it on expected losses rather than incurred losses. These expected credit losses will be recognized as an entity should measure inventory withinallowance rather than as a direct write down of the scope of this update at the lower ofamortized cost and net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. Thisbasis. The new guidance wasis effective January 1, 2017,2020 and was applied prospectively andusing a modified retrospective approach. The adoption of this new guidance did not have a material impact on the Partnership's balance sheets.

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(b)    Future Accounting Changes

RevenuePartnership’s financial statements.

Reference rate reform
In March 2020, in response to the expected cessation of LIBOR from contracts with customers

In 2014,late 2021 to mid-2023, the FASB issued new optional guidance on revenue from contracts with customers.that eases the potential burden of accounting for reference rate reform. The new guidance requiresprovides optional expedients for contracts and hedging relationships that an entity recognizes revenue with a prescribed model. This model is used to depict the transfer of promised goods or services to customers in an amount that reflects the total consideration to which the company expects to be entitled during the termare affected by reference rate reform, if certain criteria are met. Each of the contract in exchange for those goods or services. The new guidance also requires additional disclosures about the nature, amount, timing and uncertainty of revenue and the related cash flows. The Partnership will adopt the new standard on the effective dateexpedients can be applied as of January 1, 2018. There are two methods in which the new standard can be adopted: (1) a full retrospective approach with restatement of all prior periods presented, or (2) a modified retrospective approach with a cumulative-effect adjustment as of the date of adoption. The Partnership will adopt the guidance using the modified retrospective approach with the cumulative-effect of the adjustment recognized at the date of adoption, subject to allowable and elected practical expedients.

The Partnership has identified all existing customer contracts that are within the scope of the new guidance. The Partnership has completed its analysis and has not identified any material differences in the amount and timing of revenue recognition through. The Partnership will not require a cumulative-effect adjustment to opening partners' equity on January 1, 2018.

Although revenues will not be materially impacted by the guidance, the Partnership will be required to add significant disclosures based on the prescribed requirements. These new disclosures will include information regarding the significant judgments used in evaluating when and how revenue is recognized and information related to contract assets and deferred revenues. In addition, the new guidance requires that the Partnership's revenue recognition policy disclosure includes additional detail regarding the various performance obligations and the nature, amount, timing and estimates of revenue and cash flows generated from contracts with customers. The Partnership has addressed system and process changes necessary to compile the information to meet the recognition and disclosure requirements of the new guidance.

Leases

In February 2016, the FASB issued new guidance on the accounting for leases. The new guidance amends the definition of a lease requiring the customer to have both (1) the right to obtain substantially all of the economic benefits from the use of the asset and (2) the right to direct the use of the asset in order for the arrangement to qualify as a lease. The new guidance also establishes a right-of-use (ROU) model that requires a lessee to recognize a ROU asset and corresponding lease liability on the balance sheet for all leases with a term longer than 12 months. Leases will be classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The new guidance does not make extensive changes to lessor accounting.

The new guidance is effective on January 1, 2019, with early adoption permitted. A modified retrospective transition approach is required for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available.2020 through December 31, 2022. The Partnership is continuing to identify and analyze existing lease agreements to determine the effect of adoption of the new guidancereference rate reform on its consolidated financial statements. The Partnership is also addressing systemwill continue to evaluate the timing and process changes necessary to compile the information to meet the recognition and disclosure requirements of the new guidance. The Partnership continues to monitor and analyze additional guidance and clarification provided by FASB.

4.    U.S. TAX REFORM IMPACT

On December 22, 2017, the President of the United States signed into law H.R. 1 (the Tax Cuts and Jobs Act). This legislation provides for major changes to U.S. corporate federal tax law; including a reduction in the U.S. corporate tax rate to 21 percent from 35 percent. As a Texas general partnership, the Partnership is a non-taxable pass through entity and income taxes owed as a result of the Partnership's earnings are the responsibility of each partner, therefore no amounts have been recorded in the Partnership's financial statements as a result of the Tax Cuts and Jobs Act.

The Partnership is regulated by the FERC, which approves its rates, the most recent of which were established through a negotiated settlement that did not ascribe any specific cost of service elements to income taxes. While the FERC also evaluates the Partnership's rate of return on an overall cost-of-service basis, they provide for a recovery of the Partnership's ultimate taxable owners' income tax expense and related balance sheet accounts as components of the maximum recourse rates that may be charged to customers. As a non-taxable pass through entity, the Partnership does not recognize income tax expense nor has it established deferred income tax assets or liabilities. Income tax related expenses, benefits, assets, and liabilities attributable to regulated operations are the responsibility of the ultimate taxable owners of the Partnership and any adjustment to income tax accounts following the Tax Cuts and Jobs Act must be evaluated by those owners.

The Partnership cannot predict the ultimate impact; if any, of lower U.S. corporate tax rates on its future revenues. If in the future the FERC were to require a change in the Partnership's maximum recourse rates related to the change in the U.S. corporate tax rate, the Partnership expects rates would be revised through future rate proceedings or other regulatory action.

At December 31, 2017, the Partnership considers its assessment of thepotential impact of the Tax Cuts and Jobs Act to be its best interpretationadoption of available guidance. Should additional guidance on the impact of the Tax Cuts and Jobs Act on non-taxable partnerships be provided by regulatory, tax and accounting authorities or other sources in the future, the Partnership will review the approach used and adjust as appropriate.

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5.optional expedients when deemed necessary.


4. CONTINGENCIES AND COMMITMENTS

(a)Contingencies

The Partnership is subject to various legal proceedings in the ordinary course of business. The accounting for contingencies covers a variety of business activities, including contingencies for legal and environmental liabilities. The Partnership accrues for these contingencies when the assessments indicate that it is probable that a liability has been incurred or an asset will not be recovered, and an amount can be reasonably estimated in accordance withASC 450, Contingencies. The Partnership bases these estimates on currently available facts and the estimates of the ultimate outcomes or resolution. Actual results may vary from estimates resulting in an impact, positive or negative, on results of operations and cash flows. The Partnership is not aware
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of any contingent liabilities that would have a material adverse effect on the Partnership'sPartnership’s financial condition, results of operations, or cash flows.

(b)Regulatory Matters

The FERC regulates the rates and charges for transportation of natural gas in interstate commerce. Natural gas companies may not charge rates that have been determined to be unjust and unreasonable by the FERC. Generally, rates for interstate pipelines are based on the cost of service, including recovery of and a return on the pipeline'spipeline’s actual prudent historical cost investment. The rates and terms and conditions for service are found in each pipeline'spipeline’s FERC-approved tariff. Under its tariff, an interstate pipeline is allowed to charge for its services on the basis of stated transportation rates. Transportation rates are established periodically in FERC proceedings known as rate cases. The tariff also allows the interstate pipeline to provide services under negotiated and discounted rates.

Effective January 1, 2013, the


The Partnership implemented new rates asoperates under a result of itssettlement approved by FERC approved settlement agreement (2012 Settlement) with its customers and requires the Partnership to file for new rates no later than January 1, 2018. On December 4, 2017, Northern Border filed a rate settlement with FERC precluding the need to file a general rate case byeffective January 1, 2018 (2017 Settlement). The 2017
Settlement if approved by FERC, providesprovided for tiered rate reductions beginningfrom January 1, 2018 with no changeto December 31, 2019 that equates to an overall rate
reduction of 12.5% by January 1, 2020 when compared to the underlying rate design.2017 rates (10.5% by December 31, 2019 and additional
2% by January 1, 2020). The 2017 Settlement doesdid not contain anya moratorium and the Partnership is required to file new rates effective July 1, 2024. Effective February 1, 2019, FERC approved an additional 2% rate reduction to July 1, 2024 unless superseded by a subsequent rate case or settlement, recourse rates in effect at December 31, 2017, will decrease by 5.0% on January 1, 2018; by an additional 5.5% on April 1, 2018; and by a further 2.0% beginning January 1, 2020 through December 31, 2023, when the Partnership will be required to establish new rates. This equates to an overall rate reduction of 12.5% by January 1, 2020 from the recourse rates in effect at December 31, 2017.

settlement.


Compressor Usage Surcharge
The compressor usage surcharge is designated to recover the actual costs of electricity at the Partnership'sPartnership’s electric compressors and any compressor fuel use taxes imposed on its pipeline system. Any difference between the compressor usage surcharge collected and the actual costs for electricity and compressor fuel use taxes is recorded as either an increase to expense for an over recoveryover-recovery of actual costs or as a decrease to expense for an under recoveryunder-recovery of actual costs and is included in operations and maintenance expense on the income statement and reported as current asset or current liability on the balance sheets. The compressor usage surcharge rate is adjusted annually. The current asset or current liability recognized will reflect the net over or under recovery of actual compressor usage related costs at the date of the balance sheet. As of December 31, 20172020, and 2016,2019, the Partnership had recorded $0.8$1.5 million and $1.3 million as prepaid expenses other and $0.2 million as other current liabilities,regulatory liability, respectively, on the accompanying balance sheets for the net over and under recoveries of compressor usage related costs.

(c)Environmental Matters
The Partnership is not aware of any material contingent liabilities with respect to compliance with applicable environmental laws and regulations.
(d)Commitments

The Partnership makes payments under non-cancelable leases on office space and rights-of-wayits right-of-way commitments. The Partnership'sPartnership’s expense incurred for these commitments was $2.9 million for the year ended December 31, 2020, $2.9 million and $3.0 million for each of the years ended December 31, 2017, 2016,2019, and 2015,2018, respectively. The Partnership'sPartnership’s future minimum payments on these arrangementsits rights-of-way commitments are as follows:


Year Ending (In thousands)
 
Rights-of-Way
 
Office Space
 
Total

 2018 2,214 393 2,607
 2019 2,215 393 2,608
 2020 2,232 211 2,443
 2021 2,567 28 2,595
 2022 2,568 28 2,596
 Thereafter 39,927 85 40,012

  $51,723 $1,138 $52,861

Year EndingRights-of-Way
(In thousands)
20212,565 
20222,566 
20232,566 
20242,565 
20252,582 
Thereafter32,249 
$45,093 

Approximately 90 miles of Partnership's pipeline system is located within the boundaries of the Fort Peck Indian Reservation in Montana. The Partnership has a pipeline right-of-way leaserights-of-way commitment with the Assiniboine and Sioux Tribes of the Fort Peck Indian Reservation, the term of which expires in 2061. In conjunction with obtaining right-of-way access across tribal lands located within the exterior boundaries of the Fort Peck

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Indian Reservation, the Partnership also obtained right-of-way access across allotted lands located within the reservation boundaries. With the exception of one tract subject to a right-of-way grant expiring in 2035, the allotted lands are subject to a perpetual easement granted by the Bureau of Indian Affairs (BIA) for and on behalf of the individual allottees.

6.


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5. CREDIT FACILITIESFACILITY AND LONG-TERM DEBT

The Partnership'sPartnership’s long-term debt outstanding consisted of the following at December 31:


(In thousands)
 
2017
 
2016
 

 
2011 Credit Agreement – average interest rate of 2.695% at December 31, 2017 due 2020 $15,500 181,500 
2001 Senior Notes – 7.50%, due 2021 250,000 250,000 
Unamortized debt discount (188)(230)
Unamortized debt expense (1,256)(1,725)

 
  $264,056 429,545 

 

20202019
(In thousands)
2011 Credit Agreement – average interest rate of 1.717% at December 31, 2020; due 2024 (a)
$130,400 115,500 
2001 Senior Notes – 7.50%, due 2021(b)
250,000 250,000 
Total380,400 365,500 
Less: Unamortized debt issuance costs42 94 
Less: Unamortized debt expense589 1,054 
Less Current maturities of long-term debt250,000 — 
Total long-term debt, net$129,769 364,352 
(a)In June 2019, the Partnership borrowed an additional $100 million under its 2011 Credit Agreement to finance an additional cash distribution of $100 million, or $50 million to each partner.
(b)The Partnership's 2001 Senior Notes due in 2021 is expected to be refinanced prior to maturity.
On November 16, 2011, the Partnership entered into a $200 million amended and restated revolving credit agreement (2011 Credit Agreement) with certain financial institutions. The 2011 Credit Agreement is generally used by the Partnership to finance ongoing working capital needs and for other general business purposes, including capital expenditures. On October 8, 20151, 2019, the Partnership closed on the renewal and first extension of the 2011 Credit Agreement that was to expire on November 16, 2016 for an additional five years, maturing on October 9, 2020.

On August 26, 2016, the $100 million 2009 Senior Notes matured and the repayment was financed through a $100 million draw on the Partnership's 2011 Credit Agreement, which brought the Partnership's outstanding borrowings underextended the 2011 Credit Agreement to $181.5 million.

On November 15, 2016,extend the Partnership entered into a $100 million 364-day Revolving Credit Agreement (364-day Credit Agreement) that expired on November 14, 2017, which utilized the same covenants as the 2011 Credit Agreement. As a result of the shared covenants, the 2011 Credit Agreement was amended for the second time to include the cross default with the 364-day Credit Agreement.

On Septembermaturity until October 1, 2017, the Partnership paid down the outstanding borrowings under the 2011 Credit Agreement from $181.5 million to $15.5 million. The $166 million payment was financed through contributions from partners of $83 million each. At the time of the payment on the 2011 Credit Agreement, the Partnership also terminated the 364-day Credit Agreement.

2024.

At December 31, 2017,2020, the Partnership'sPartnership’s outstanding borrowings under the 2011 Credit Agreement were $15.5$130.4 million, leaving $184.5$69.6 million available for future borrowings. The Partnership may, at its option, so long as no default or event of default has occurred and is continuing, elect to increase the capacity under its 2011 Credit Agreement byhave accordion features for an aggregate amount notadditional capacity of $200 million, subject to exceed $300 million, provided that lenders are willing to commit additional amounts.lender consent. At the Partnership'sPartnership’s option, the interest rate on the outstanding borrowings may be the lenders' base rate or the London Interbank Offered Rate plus an applicable margin that is based on its long-term unsecured credit ratings. The 2011 Credit Agreement permits the Partnership to specify the portion of the borrowings to be covered by specific interest rate options and to specify the interest rate period. The Partnership is required to pay a commitment fee based on its credit rating and on the unused principal amount of the commitment of $200 million under the 2011 Credit Agreement.


Certain of the Partnership'sPartnership’s long-term debt arrangements contain covenants that restrict the incurrence ofPartnership's ability to incur secured indebtedness or liens upon property by the Partnership. Under the 2011 Credit Agreement, the Partnership is required to comply with certain financial, operational and legal covenants. Among other things, the Partnership is required to maintain a leverage ratio (total consolidated debt to consolidated EBITDA (net income plus interest expense, income taxes, depreciation and amortization and all other non-cash charges)) of no more than 5.00 to 1.1.00. Pursuant to the 2011 Credit Agreement, if one or more specified material acquisitions are consummated, the permitted leverage ratio is increased to 5.50 to 11.00 for the first two full calendar quarters following the acquisition. Upon any breach of these covenants, amounts outstanding under the 2011 Credit Agreement may become immediately due and payable.

At December 31, 2017,2020, the Partnership was in compliance with all of its financial covenants.

Aggregate required repayment of

The Partnership’s long-term debt forrepayments consisted of the next five years is $265.5 million, with $15.5 million due in 2020 and $250 million due in 2021. There are no required repayment obligations for 2018, 2019, or 2022.

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7.    DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

Prior tofollowing at December 31, 2001, the Partnership terminated a series2020 (in thousands of interest rate derivatives in exchange for cash. These derivatives had previously been accounted for as hedges with $4.1 million recorded in accumulated other comprehensive loss (AOCL) as of the termination date. The previously recorded AOCL is currently being amortized under the effective interest method over the remaining term of the related hedged instrument, the Partnership's 2001 Senior Notes due 2021.

During the three-year period ended December 31, 2017, the Partnership reclassified the below amounts from AOCL into earnings for these terminated derivatives.

Net Loss Reclassified from AOCL into Income (Effective Portion)   Years Ended December 31,

 
(In thousands) 
Statements of Income Caption
 
2017
 
2016
 
2015
 

 
Cash flow hedges Interest expense $(285)(264)(245)

At December 31, 2017 and 2016, AOCL was $1.3 million and $1.5 million, respectively, and is being amortized through 2021 as noted above. The Partnership expects to reclassify $0.3 million from AOCL as an increase to interest expense in 2018. The Partnership had no other derivative instruments during the period ended December 31, 2017.

8.dollars):

Year Ending
2021250,000 
2022— 
2023— 
2024130,400 
$380,400 
6. FAIR VALUE MEASUREMENTS

(a)Fair Value Hierarchy

Under ASC 820,Fair Value Measurement, fair value measurements are characterized in one of three levels based upon the input used to arrive at the measurement. The three levels of the fair value hierarchy are as follows:

Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the Partnership has the ability to access at the measurement date.

Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

Level 3 inputs are unobservable inputs for the asset or liability.

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When appropriate, valuations are adjusted for various factors including credit considerations. Such adjustments are generally based on available market evidence. In the absence of such evidence, management'smanagement’s best estimate is used.

(b)Fair Value of Financial Instruments

The following table presents the carrying amounts and estimated fair values of the Partnership's financial instruments at December 31, 2017 and 2016. The fair value of a financial instrument is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.

  2017

 2016

  
Carrying
Amount
 
Fair
Value
 
Carrying
Amount
 
Fair
Value

Financial asset:        
 Cash and cash equivalents $14,010 14,010 13,535 13,535
Financial liability:        
 Long-term debt 265,500 294,154 431,500 464,357

The following methods and assumptions were used to estimate the fair value of each class of financial instruments:

Cash and cash equivalents – 

The carrying amountvalue of cash and cash equivalents, approximatesaccrued interest, all current receivable and payable accounts, except for natural gas imbalances are classified as Level 1 in fair value due tohierarchy. Accordingly, the carrying values approximate their fair values because of the short maturity or duration of these investments.

Long-term debt – instruments.

The fair valuePartnership’s natural gas imbalances, which are reported as part of senior notes was estimated based on quoted market prices for the same or similar debt instruments with similar termsaccounts receivable, accounts payable and remaining maturities, which isrelated party accounts, are classified as a Level 2 in the "Fair“Fair Value Hierarchy", whereHierarchy,” as the fair value is determined by using

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valuation techniques that refer toapproach includes quoted prices in the market index and observable market data. The Partnership presently intends to maintain the current schedule of maturitiesvolumes for the 2001 Senior Notes, which will result in no gains or losses on its repayment. The fair value of the 2011 Credit Agreement approximates the carrying value since the interest rates are periodically adjusted to reflect current market conditions.

(c)    Other Recurring Fair Value of Financial Instruments

The following table presents the carrying amounts and estimated fair values of other items measured and recorded at fair value on a recurring basis as of December 31, 2017 and 2016:

  2017

 2016

  
Carrying
Amount
 
Fair
Value
 
Carrying
Amount
 
Fair
Value

Natural gas imbalance asset $815 815 44 44
Related party natural gas imbalance asset 
 
 951 951
Natural gas imbalance liability 1,232 1,232 2,484 2,484
Related party natural gas imbalance liability $308 308  

Natural Gas Imbalances –imbalance. Natural gas imbalances represent the difference between the amount of natural gas delivered to or received from a pipeline system and the amount of natural gas scheduled to be delivered or received at current market prices. The Partnership valuesrecords these imbalances at fair value by applying the difference between the measured quantities of natural gas delivered to or received from its shippers and operators to the current average of the Northern Ventura index price and the Chicago city-gates index price. The Partnership has classified the fair value of natural gas imbalances as a Level 2 in the "Fair Value Hierarchy," as the valuation approach includes quoted prices in the market index and observable volumes for the imbalance.

9.    TRANSACTIONS WITH MAJOR CUSTOMERS

For the year ended December 31, 2017,2020, the total estimated fair value of our natural gas imbalance was a net payable of approximately $1.5 million. (2019- net payable of $1.5 million). For the year ended December 31, 2020, the total estimated fair value of our related party natural gas imbalance was a net payable of approximately $0.1 million. (2019- net receivable of $0.6 million).

For the year ended December 31, 2020, the fair value of the Partnership’s long term debt was $391.3 million (2019-$381.6 million) The fair value was estimated based on quoted market prices for the same or similar debt instruments with similar terms and remaining maturities, which is classified as Level 2 in the “Fair Value Hierarchy”, where the fair value is determined by using valuation techniques that refer to observable market data.

7. REVENUES
(a)Disaggregation of Revenues
For the years ended December 31, 2020 and 2019, effectively all of the Partnership’s revenues were from capacity arrangements and transportation contracts with customers as discussed under Note 2(j).
(b)Contract Balances
The Partnership’s contract balances consist primarily of receivables from contracts with customers reported under Accounts receivable in the balance sheet. Additionally, our accounts receivable represents the Partnership’s unconditional right to consideration for services completed which includes billed and unbilled accounts.
(c)Right to invoice practical expedient
In the application of the right to invoice practical expedient, the Partnership’s revenues from regulated capacity arrangements are recognized based on rates specified in the contract. Therefore, the amount invoiced, which includes the capacity contracted and variable volume of natural gas transported, corresponds directly to the value the customer received. These revenues are recognized monthly once the Partnership’s performance obligation to provide capacity has been satisfied.

8. TRANSACTIONS WITH MAJOR CUSTOMERS
The following table represents the shippers providing significant operating revenues to the Partnership were Sequent Energy Management, for the year ended December 31 (in thousands):
202020192018
ONEOK Rockies (a)
$59,844 39,549 29,425 
Tenaska Marketing Ventures39,104 42,032 38,744 
BP Canada Energy Marketing Group22,096 23,112 27,538 
Sequent Energy18,552 20,297 27,806 
(a)ONEOK Rockies Midstream, L.L.C. (ONEOK Rockies), is a subsidiary of ONEOK BP Canada, and Tenaska Marketing VenturesInc.
The following table represents the amounts in the Partnership’s trade or related party accounts receivable for shippers with revenues of $34.6 million, $31.5 million, $30.2 million, and $28.7 million, respectively. At December 31, 2017, Tenaska Marketing Ventures, EDF Trading North America, ONEOK Rockies and Sequent Energy Management, owed the Partnership approximately $3.1 million, $3.1 million, $2.8 million and $2.7 million, respectively, which isaccounts receivable balances greater than 10 percent of the Partnership's tradePartnership’s accounts receivable.

For the year ended December 31, 2016, shippers providing significant operating revenues to the Partnership were BP Canada, Tenaska Marketing Ventures, receivable (in thousands).

20202019
Tenaska Marketing Ventures$3,637 3,337 
ONEOK Rockies (a)3,221 3,735 
(a)ONEOK Rockies and EDF Trading North America with revenuesMidstream, L.L.C. (ONEOK Rockies), is a subsidiary of $29.5 million, $28.5 million, $28.4 million and $27.9 million, respectively. At December 31, 2016, Sequent Energy Management, Tenaska Marketing Ventures, and ONEOK Rockies owed the Partnership approximately $3.2 million, $2.9 million, and $2.6 million, respectively, which is greater than 10 percentInc.

TC PipeLines, LP Annual Report 2020F-43

Table of the Partnership's trade accounts receivable.

For the year ended December 31, 2015, shippers providing significant operating revenues to the Partnership were BP Canada and Sequent Energy Management with revenues of $26.2 million and $24.7 million, respectively.

10.Contents

9. TRANSACTIONS WITH RELATED PARTIES

The day-to-day management of the Partnership'sPartnership’s affairs is the responsibility of TransCanada Northern Border, Inc., a wholly owned subsidiary of TC Energy, (TransCanada Northern Border) pursuant to an operating agreement between TransCanada Northern Border and the Partnership effective April 1, 2007.2007 (as amended). TransCanada Northern Border utilizes the services of TransCanada Corporation (TransCanada)TC Energy and its affiliates for management services related to the Partnership. The Partnership is charged for the capital, salaries, benefits and expenses of TransCanadaTC Energy and its affiliates attributable to the Partnership'sPartnership’s operations. For the years ended December 31, 2017, 2016,2020, 2019, and 2015,2018, the Partnership'sPartnership’s charges from TransCanadaTC Energy and its affiliates totaled approximately $43.3$38.9 million, $32.0$39.2 million, and $36.4$35.6 million, respectively. The impact of these charges on the Partnership'sPartnership’s income was $31.3$32.1 million, $24.4$36.3 million, and $28.0$32.2 million, respectively. At December 31, 20172020 and 2016,2019, the Partnership owed $3.6$2.4 million and $3.5$3.6 million, respectively, to these affiliates classified to related party accounts on the balance sheets.

For the years ended December 31, 2017, 2016,2020, 2019, and 2015,2018, the Partnership had contracted firm capacity held by one customertwo customers affiliated with onethe Partnership’s general partners, namely ONEOK Rockies, a subsidiary of the Partnership's general partners. RevenuesONEOK Inc. and beginning in November 2020, TC Energy Marketing, Inc (TC Energy Marketing), a wholly owned subsidiary of TC Energy. Revenue and outstanding receivable from TC Energy Marketing are $0.8 million and $0.4 million, respectively. See Note 9 – Transactions with Major Customers for details regarding revenues and outstanding accounts receivable balances with ONEOK Rockies for 2017, 2016, and 2015 were $31.5 million, $28.4 million, and $22.6 million, respectively. At December 31, 2017 and 2016, the Partnership had outstanding receivables from ONEOK Rockies of $2.8 million and $2.6 million, respectively.

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11.past three years.


10. CASH DISTRIBUTION AND CONTRIBUTION POLICY

The Partnership'sPartnership’s General Partnership Agreement provides that distributions to its partners are to be made on a pro rata basis according to each partner'spartner’s capital account balance. The Partnership'sPartnership’s Management Committee determineshas the responsibility to determine the amount and timing of the distributions to its partners including equity contributions and the funding of growth capital expenditures. In addition, any inability to refinance maturing debt will be funded by equity contributions. Any changes to, or suspension of, the Partnership'sPartnership’s cash distribution policy requires the unanimous approval of the Management Committee. The Partnership'sPartnership’s cash distributions are equal to 100 percent of its distributable cash flow as determined from its financial statements based upon earnings before interest, taxes, depreciation and amortization less interest expense and maintenance capital expenditures. Effective April 1, 2016, theThe Partnership transitioned from quarterly distributions paid approximately one month following the end of the quarter to monthly distributions paid approximately one month following the end of each reported month.

For the years ended December 31, 2017, 2016,2020, 2019, and 2015,2018, the Partnership paid distributions to its general partners of $165.9$181.6 million, $209.8$286.9 million and $182.2(including the distribution of $100 million respectively. In 2017,from the Partnership received contributions from its partnersproceeds of $166 million, $83 million each, which was used as a payment onadditional borrowings under the 2011 Credit Agreement.

12.Agreement, see Note 5), and $166.4 million, respectively.


11. SUBSEQUENT EVENTS

On January 8, 2018, the Management Committee of15, 2021, the Partnership declared a cash distribution in the amount of $14.8$16.4 million. The distribution was paid on January 31, 2018.

29, 2021.

On February 14, 2018, the Management Committee of16, 2021, the Partnership declared a cash distribution in the amount of $17.1$18.1 million. The distribution will be paid on February 28, 2018.

26, 2021.

Subsequent events have been assessed through February 16, 2018,19, 2021, which is the date the financial statements were issued, and we concluded there were no events or transactions during this period that would require recognition or disclosure in the financial statements other than those already reflected.

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 2020

Table of Contents
GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP

Financial Statements

December 31, 2017 and 2016

(With

Independent Auditors'Auditors’ Report Thereon)


GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP
INDEPENDENT AUDITORS' REPORT


The Partners and the Management Committee
Great Lakes Gas Transmission Limited Partnership:

Report on the Financial Statements


We have audited the accompanying financial statements of Great Lakes Gas Transmission Limited Partnership, (the Partnership), which comprise the balance sheets as of December 31, 20172020 and 2016,2019, and the related statements of income and partners'partners’ capital, and cash flows for each of the years in the three-year period ended December 31, 2017,2020, and the related notes to the financial statements.

Management's


Management’s Responsibility for the Financial Statements

Management is responsible for the preparation and fair presentation of these financial statements in accordance with U.S. generally accepted accounting principles; this includes the design, implementation, and maintenance of internal control relevant to the preparation and fair presentation of financial statements that are free from material misstatement, whether due to fraud or error.

Auditors'


Auditors’ Responsibility

Our responsibility is to express an opinion on these financial statements based on our audits.We conducted our audits in accordance with auditing standards generally accepted in the United States of America. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free from material misstatement.

An audit involves performing procedures to obtain audit evidence about the amounts and disclosures in the financial statements. The procedures selected depend on the auditors'auditors’ judgment, including the assessment of the risks of material misstatement of the financial statements, whether due to fraud or error. In making those risk assessments, the auditor considers internal control relevant to the entity'sentity’s preparation and fair presentation of the financial statements in order to design audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the entity'sentity’s internal control. Accordingly, we express no such opinion. An audit also includes evaluating the appropriateness of accounting policies used and the reasonableness of significant accounting estimates made by management, as well as evaluating the overall presentation of the financial statements.

We believe that the audit evidence we have obtained is sufficient and appropriate to provide a basis for our audit opinion.


Opinion

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of Great Lakes Gas Transmission Limited Partnership as of December 31, 20172020 and 2016,2019, and the results of its operations and its cash flows for each of the years in the three-year period ended December 31, 2017,2020 in accordance with U.S. generally accepted accounting principles.



/s/ KPMG, LLP

LLC

Houston, Texas
February 16, 2018

22, 2021

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2020F-45

Table of Contents


GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP
BALANCE SHEETS


December 31, 2017 and 2016 (In Thousands)
 
2017
 
2016
  

Assets      
Current assets:      
 Cash and cash equivalents $               44               39  
 Demand loan receivable from affiliate 64,040 27,144  
 Accounts receivable:      
  Trade 7,409 7,351  
  Affiliates 20,236 19,185  
 Materials and supplies 9,689 10,150  
 Other 5,356 2,287  

   Total current assets 106,774 66,156  

Property, plant, and equipment:      
 Property, plant, and equipment 2,105,808 2,087,281  
 Construction work in progress 1,330 5,853  

  2,107,138 2,093,134  
Less accumulated depreciation and amortization (1,406,348)(1,379,043) 

   Total property, plant, and equipment, net 700,790 714,091  

   Total assets $     807,564 780,247  

Liabilities and Partners' Capital      
Current liabilities:      
 Accounts payable:      
  Trade $       8,095 11,772  
  Affiliates 4,919 3,744  
 Provision for revenue sharing refund(Note 2(j)) 39,601 7,200  
 Provision for rate refund (Note 5) 7,972   
 Current maturities of long-term debt 19,000 19,000  
 Taxes payable (other than income) 7,916 7,990  
 Accrued interest 6,240 6,543  
 Other current liabilities  2,767  

   Total current liabilities 93,743 59,016  
Long-term debt, net of current maturities 239,753 258,712  
Regulatory liabilities 744   
Other noncurrent liabilities 212 226  
Partners' capital 473,112 462,293  

   Total liabilities and partners' capital $     807,564 780,247  

December 31, 2020 and 2019 (In Thousands)
20202019
Assets
Current assets:
Cash and cash equivalents46 39 
Demand loan receivable from related party26,886 34,262 
Accounts receivable:
Trade8,491 7,016 
Related parties17,184 19,262 
Materials and supplies10,200 9,850 
Regulatory Assets1,314 — 
Other1,409 1,858 
Total current assets65,530 72,287 
Property, plant, and equipment:
Property, plant, and equipment2,178,171 2,130,615 
Construction work in progress13,482 3,129 
2,191,653 2,133,744 
Less accumulated depreciation and amortization(1,475,580)(1,448,825)
Total property, plant, and equipment, net716,073 684,919 
Total assets$781,603 757,206 
Liabilities and Partners' Capital
Current liabilities:
Accounts payable:
Trade$8,982 6,395 
Related parties3,224 5,108 
Current maturities of long-term debt31,000 21,000 
Taxes payable (other than income)8,513 7,989 
Accrued interest5,197 5,554 
Other current liabilities11,972 8,434 
Total current liabilities68,888 54,480 
Long-term debt, net of current maturities166,848 197,817 
Regulatory liabilities and other8,708 5,953 
Partners' capital537,159 498,956 
Total liabilities and partners' capital$781,603 757,206 
See accompanying notes to financial statements.

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GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP
STATEMENTS OF INCOME AND PARTNERS' CAPITAL


Years ended December 31, 2017, 2016, and 2015 (In Thousands)
 
2017
 
2016
 
2015
  

Operating revenues,net (Note 2(j)) $181,487 179,133 176,901  
Operating expenses:        
 Operation and maintenance 54,885 58,048 49,222  
 Depreciation and amortization 29,474 27,911 27,756  
 Taxes, other than income 10,830 10,872 10,637  

  Total operating expenses 95,189 96,831 87,615  

  Operating income 86,298 82,302 89,286  
Other income, net 480 521 1,511  
Interest and debt expense (20,831)(22,295)(23,946) 
Affiliated interest income 372 114 54  

  Net income $  66,319 60,642 66,905  

Partners' capital:        
 Balance at beginning of year $462,293 484,951 460,446  
 Net income 66,319 60,642 66,905  
 Distributions to partners (74,500)(102,300)(61,400) 
 Contributions from partners 19,000 19,000 19,000  

 Balance at end of year $473,112 462,293 484,951  

Years ended December 31, 2020, 2019,
and 2018 (In Thousands)
202020192018
Operating revenues, net (Note 8)
$238,839 237,894 245,646 
Operating expenses:
Operation and maintenance57,469 67,996 56,613 
Depreciation and amortization32,958 31,954 31,813 
Taxes, other than income12,035 10,848 11,651 
Total operating expenses102,462 110,798 100,077 
Operating income136,377 127,096 145,569 
Interest and debt expense:
Interest expense16,069 17,747 19,378 
Interest expense capitalized(185)(119)(184)
Interest expense, net15,884 17,628 19,194 
Other income:
Allowance for equity funds used during construction800 411 308 
Other income210 1,203 979 
Total other income1,010 1,614 1,287 
Net income$121,503 111,082 127,662 
Partners' capital:
Balance at beginning of year$498,956 494,174 473,112 
Net income121,503 111,082 127,662 
Distributions to partners(104,300)(127,300)(125,600)
Contributions from partners21,000 21,000 19,000 
Balance at end of year$537,159 498,956 494,174 
See accompanying notes to financial statements.

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GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP
STATEMENTS OF CASH FLOWS

Years ended December 31, 2017, 2016, and 2015
(In Thousands)
 2017 2016 2015 

 
Cash flows from operating activities:       
 Net income $  66,319 60,642 66,905 
 Adjustments to reconcile net income to net cash provided by operating activities:       
  Depreciation and amortization 29,474 27,911 27,756 
  Allowance for funds used during construction, equity (116)(263)(78)
  Amortization of debt issuance cost, reported as part of interest expense 41 82 46 
  Asset and liability changes:       
   Accounts receivable (1,109)(4,437)2,191 
   Other current assets (2,608)321 (1,107)
   Accounts payable (1,792)1,043 (941)
   Provision for revenue sharing refund 32,401 5,300 1,900 
   Provision for rate refund 7,972   
   Other current liabilities (3,144)2,712 (9,579)
   Noncurrent liabilities (14)(9)(10)

 
    Net cash provided by operating activities 127,424 93,302 87,083 

 
Cash flows from (used in) investing activities:       
 Additions to property, plant, and equipment (13,814)(14,885)(7,265)
 Net change in demand loan receivable from affiliate (36,896)23,928 (20,670)
 Other (2,209)(54)2,263 

 
    Net cash provided by (used in) investing activities (52,919)8,989 (25,672)

 
Cash flows used in financing activities:       
 Payments for retirement of long-term debt (19,000)(19,000)(19,000)
 Distributions to partners (74,500)(102,300)(61,400)
 Contributions from partners 19,000 19,000 19,000 

 
    Net cash used in financing activities (74,500)(102,300)(61,400)

 
    Net change in cash and cash equivalents 5 (9)11 
Cash and cash equivalents at beginning of year 39 48 37 

 
Cash and cash equivalents at end of year $          44 39 48 

 
Supplemental cash flow information:       
 Interest paid, net of capitalized interest $  20,791 22,529 24,153 
 Accruals for property, plant and equipment $    1,497  340 

Statements of Cash Flows
Years ended December 31, 2020, 2019, and 2018 (In
Thousands)
202020192018
Cash flows from operating activities:
Net income$121,503 111,082 127,662 
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization32,958 31,954 31,813 
Allowance for funds used during construction, equity(800)(411)(308)
Gain on sale of property, plant and equipment (780)— 
Amortization of debt issuance cost, reported as part of interest expense31 35 29 
Asset and liability changes:
Accounts receivable603 1,058 309 
Other current assets(1,215)(253)3,590 
Accounts payable(1,853)2,705 (3,207)
Provision for revenue sharing refund — (44,722)
Provision for rate refund — (2,851)
Other current and noncurrent liabilities3,711 3,747 2,337 
Net cash provided by operating activities154,938 149,137 114,652 
Cash flows from (used in) investing activities:
Additions to property, plant, and equipment(58,007)(30,234)(17,178)
Net change in demand loan receivable from related party7,376 1,672 28,106 
Proceeds from sale of property, plant and equipment 6,735 — 
Other (20)25 
Net cash provided by (used in) investing activities(50,631)(21,847)10,953 
Cash flows used in financing activities:
Contributions from partners21,000 21,000 19,000 
Payments for retirement of long-term debt(21,000)(21,000)(19,000)
Distributions to partners(104,300)(127,300)(125,600)
Net cash used in financing activities(104,300)(127,300)(125,600)
Net change in cash and cash equivalents7 (10)
Cash and cash equivalents at beginning of year39 49 44 
Cash and cash equivalents at end of year$46 39 49 
Supplemental cash flow information:
Interest paid, net of capitalized interest$16,211 17,950 19,599 
Accruals for property, plant and equipment, net$2,556 905 389 
See accompanying notes to financial statements.

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Table of Contents

GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP


NOTES TO FINANCIAL STATEMENTS
DECEMBER
December 31, 2017 AND 2016

2020 and 2019


(1) DESCRIPTION OF BUSINESS

Great Lakes Gas Transmission Limited Partnership (the Partnership) is a Delaware limited partnership that owns 2,115 miles of natural gas pipeline system, which transports natural gas for delivery to wholesale customers in the midwestern and northeastern United States (U.S.) and eastern Canada. The partners and partnershippartners’ ownership percentages in the Partnership at December 31, 20172020 and 20162019 were as follows:



Ownership
percentage



General Partners:Ownership
percentage
General Partners:
TransCanada GL, Inc.46.45 46.45
TC Pipelines, LP (TCP)TC GL Intermediate Limited Partnership46.45 46.45
Limited Partner:
Great Lakes Gas Transmission Company7.10 7.10

Great Lakes Gas Transmission Company (the Company) and, TransCanada GL Inc., and TCP are wholly owned indirect subsidiaries of TC Energy Corporation (TC Energy), formerly known as TransCanada Corporation (TransCanada). TC GL Intermediate Limited Partnership's parent, TC PipeLines, LP is also an indirect subsidiary of TransCanada.

Corporation.


(2) SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

(a)Basis of Presentation

The Partnership'sPartnership’s financial statements have been prepared by management in accordance with U.S. generally accepted accounting principles (GAAP).

Certain prior year amounts have been reclassified to conform to the current year presentation.

(b)Use of Estimates

The preparation of the financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.

(c)Cash and Cash Equivalents

The Partnership'sPartnership’s cash and cash equivalents consist of cash and highly liquid short-term investments with original maturities of three months or less and are recorded at cost, which approximates fair value.

(d)Accounting for Regulated Operations

The Partnership'sPartnership’s natural gas pipeline is subject to the jurisdiction of the Federal Energy Regulatory Commission (FERC) under the Natural Gas Act of 1938 and the Natural Gas Policy Act of 1978. Financial Accounting Standards Board Accounting Standards Codification (ASC) 980, Regulated Operations, provides that rate regulated enterprises account for and report assets and liabilities consistent with the economic effect of the way in which regulators establish rates, if the rates are designed to recover the costs of providing the regulated service and if the competitive environment makes it probable that such rates can be charged and collected. The Partnership evaluates the continued applicability of regulatory accounting, considering such factors as regulatory charges, the impact of competition, and the ability to recover regulatory assets as set forth in ASC 980. Accordingly, certain assets and liabilities that result from the regulated ratemakingrate-making process are reflected on the

TC PipeLines, LPAnnual Report2017    F-55



balance sheets as regulatory assets and regulatory liabilities. The following table presents the Partnership’s regulatory assetsasset and liabilities at December 31, 20172020 and 2016:

 
 
December 31,

  
  
 
 
Remaining
recovery/
settlement
period

  
 
 
2017

 
2016

  

   (In thousands) (Years)  
Regulatory Assets         
Volumetric fuel tracker  2,787  (a) 

Less: Current portion included in Other  2,787     

  $     

Regulatory Liabilities         
Negative salvage $744  (b) 
Volumetric fuel tracker   2,767 (a) 

    2,767    
Less: Current portion included in Other   2,767    

  $744     

2019:
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Table of Contents
December 31,
20202019Remaining
recovery/
settlement
period
(In thousands)(Years)
Regulatory Assets
Volumetric fuel tracker$1,314 — (a)
Regulatory Liabilities
Negative salvage$8,697 5,948 (b)
Volumetric fuel tracker 686 (a)
8,697 6,634 
Less: Current portion included in Other 686 
$8,697 5,948 
(a)
Volumetric fuel tracker assets or liabilities are settled with in-kind exchanges with customers continually.

(b)
Negative salvage accrued for estimated net costs of removal of transmission plant has a settlement period related to the estimated life of the assets (refer to Note 4(b)2(h)).


(e)Trade Accounts Receivable

Trade accounts receivable are recorded at the invoiced amount and do not bear interest, except for those receivables subject to late charges. The Partnership maintains an allowance for doubtful accounts for estimated losses on accounts receivable, if it is determined the Partnership will not collect all or part of the outstanding receivable balance. The Partnership regularly reviews its allowance for doubtful accounts and establishes or adjusts the allowance as necessary using the specific-identification method. Account balances are charged to the allowance after all means of collection have been exhausted and the potential for recovery is no longer considered probable. There were no accounts charged to the allowance in 20172020 and 2016.

2019.

(f)Natural Gas Imbalances

Natural gas imbalances occur when the actual amount of natural gas delivered to or received from a pipeline system differs from the amount of natural gas scheduled to be delivered or received. The Partnership values these imbalances due to or from shippers and operators at current index prices. Imbalances are settled in-kind, subject to the terms of the Partnership'sPartnership’s tariff.

Imbalances due from others are reported on the balance sheets as trade accounts receivable or accounts receivable from affiliates.related parties. Imbalances owed to others are reported on the balance sheets as trade accounts payable or accounts payable to affiliates.related parties. In addition, the Partnership classifies all imbalances as current as the Partnership expects to settle them within a year.

(g)Material and Supplies

The Partnership'sPartnership’s inventories primarily consist of materials and supplies and are carried at lower of weighted average cost or market.

and net realizable value.

(h)Property, Plant, and Equipment

Property, plant, and equipment are recorded at their original cost of construction. For assets the Partnership constructs, direct costs are capitalized, such as labor and materials, and indirect costs, such as overhead and interest are also capitalized. The Partnership capitalizes major units of property replacements or improvements and expenses minor items.

The Partnership uses the composite (group) method to depreciate property, plant, and equipment. Under this method, assets with similar lives and characteristics are grouped and depreciated as one asset. The depreciation rate is applied to the total cost of the group until its net book value equals its salvage value. All asset groups are depreciated using the depreciation rates approved by FERC depreciation rates.in the Partnership’s last rate proceeding. A substantial portion of the Partnership's

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Partnership’s principal operating assets are being depreciated at an annual rate of 1.27%. The remaining assets are depreciated at annual rates ranging from 2.33% to 20.00%10.00%. Using these rates, the remaining depreciable life of these assets ranges from 4 to 4454 years.

The Partnership collects estimated future removal costs related to its transmission and gathering facilities in its current rates (also known as “negative salvage”) and recognizes regulatory liabilities in this respect in the balance sheet. Estimated costs associated with the future removal of transmission and gathering facilities are collected through depreciation as allowed by FERC. These amounts do not represent asset retirement obligations as defined by ASC 410, Accounting for Asset Retirement Obligations. When property, plant, and equipment are retired, the Partnership charges accumulated depreciation and amortization for the original cost of the assets in addition to the cost to remove, sell, or dispose of the assets, less their salvage value. The Partnership does not recognize a gain or loss unless an entire operating unit is sold or retired. The Partnership includes gains or losses on dispositions of operating units in income.

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The Partnership capitalizes athe carrying cost on funds invested in the construction of long-lived assets. This carrying cost includes a return on the investment financed by debt and equity allowance for funds used during construction (AFUDC). AFUDC is calculatedrecorded based on the Partnership'sPartnership’s average cost of debt and equity. Capitalized carrying costs for AFUDC debt and equity are reflected as an increase in the cost of the asset on the balance sheets.
Capitalized AFUDC debt amounts are included as a reduction of interest and debt expense in the statements of income.

Capitalized AFUDC equity amounts are included as other income in the statements of income. Debt amounts capitalized during the years ended December 31, 2020, 2019 and 2018 were $0.2 million, $0.1 million and $0.2 million, respectively. Equity amounts capitalized during the years ended December 31, 2020, 2019 and 2018 were $0.8 million, $0.4 million and $0.3 million, respectively. Amounts included in construction work in progress are not amortized until transferred into service.

(i)Long-Lived Assets

Long-lived assets, such as property, plant, and equipment, and purchased intangible assets subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset or asset group be tested for possible impairment, the Partnership first compares undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, an impairment is recognized to the extent that the carrying value exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values, and third-party independent appraisals, as considered necessary.

(j)Revenue Recognition

The Partnership'sPartnership’s revenues are primarily generated from contractual arrangements for committed capacity and from transportation services.of natural gas. These are treated as a bundled performance obligation. Revenues for all services are based on the quantity of gas delivered or subscribed at a price specified in the contract. For the Partnership's transportation services, reservation revenues are recognized onearned from firm contracted capacity arrangements are recognized ratably over the term of the contract period regardless of the amount of natural gas that is transported. ForTransportation revenues for interruptible or volumetric-based services are recognized when the Partnership records revenues when physical deliveries of natural gas are made at the agreed-upon delivery point.service is performed. The Partnership doesutilizes the practical expedient of recognizing revenue as invoiced. Revenues are invoiced and paid monthly. The Partnership’s pipeline systems do not take ownership of the natural gas that it transports. is transported for customers. Revenues from contracts with customers are recognized net of any taxes collected from customers, which are subsequently remitted to governmental authorities.
The Partnership isPartnership's pipeline systems are subject to FERC regulations and, as a result, a portion of revenues the Partnership collectscollected may be subject to refund inif invoiced during an interim period when a rate proceeding. The Partnership establishes provisionproceeding is ongoing. Allowances for these potential refunds.refunds are recognized using management's best estimate based on the facts and circumstances of the proceeding. Any allowances that are recognized during the proceeding process are refunded or retained, as applicable, at the time a regulatory decision becomes final. As of December 31, 20172020, 2019, and 2016, the Partnership has not collected and recognized any revenue that is subject to potential refund.

The Partnership operates under a FERC approved 2013 rate settlement that includes a revenue sharing mechanism that requires the Partnership share with its shippers 50% of any qualifying revenues earned during the year that result2018, there are no refund provisions reflected in a return on equity (ROE) above 13.25%. Qualifying revenues above a 20% ROE are returned to shippers at 100%. The Partnership establishes a provision for this revenue sharing as an offset against revenue in the income statement and recognizes an estimated refund liability classified as provision for revenue sharing refund in the balance sheet. Accordingly, the revenues presented in the statement of income for the years ended December 31, 2017, 2016 and 2015 were net of $39.6 million, $7.8 million and $1.9 million estimated revenue sharing provision, respectively. During 2016, the calculation of the 2015 refund was finalized and a total of $2.5 million was refunded to qualifying shippers in November 2016. During 2017, the calculation of the 2016 refund was finalized and a total of $6.9 million was refunded to qualifying shippers in June 2017. The Partnership expects that a significant portion of the 2017 estimated revenue sharing provision will be refunded to its affiliates which is consistent with prior years.

these financial statements.

(k)    Commitments and Contingencies

Accounting for Asset Retirement Obligations

The Partnership accounts for asset retirement obligations pursuant to the provisions of ASC 410-20,Asset Retirement Obligations. ASC 410-20 requires the Partnership to record the fair value of an asset retirement obligation as a liability in the period in which it incurs a legal obligation associated with the retirement of tangible long-lived assets that result from the acquisition, construction, development, and/or normal use of the assets. ASC 410-20 also requires the Partnership to record a corresponding asset that is depreciated over the life of the asset. Subsequent to the initial measurement of the asset retirement obligation, the obligation is to be adjusted at the end of each period to reflect the passage of time and changes in the estimated future cash flows underlying the obligation.

The fair value of a liability for an asset retirement obligation is recorded during the period in which the liability is incurred and if a reasonable estimate of fair value can be made. The Partnership has determined that asset retirement obligations exist for certain of its transmission assets; however, the fair value of the obligations cannot be determined because the end of the transmission system life is not determinable with the degree of accuracy necessary to establish a liability for the obligations.
The Partnership has determined it has legal obligations associated with its natural gas pipelines and related transmission facilities. The obligations relate primarily to purging and sealing the pipelines if they are abandoned. The Partnership is also required to operate and maintain its natural gas pipeline system and intends to do so as long as supply and demand for natural gas exists, which the Partnership expects for the foreseeable future. Therefore, the Partnership believes its natural gas pipeline system assets have indeterminate lives and, accordingly, has recorded no asset retirement obligation as of December 31, 20172020 and 2016.2019. The Partnership continues to evaluate its asset retirement obligations and future developments that could impact amounts it records.

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Other Contingencies

The Partnership recognizes liabilities for contingencies when it has an exposure that, when fully analyzed, indicates it is both probable that a liability has been incurred and the amount of loss can be reasonably estimated. Where the most likely outcome of a contingency can be reasonably estimated, the Partnership accrues a liability for that amount. Where the most likely outcome cannot be estimated, a range of potential losses is established and if no one amount in that range is more likely than any other, the lower end of the range is accrued.

(l)Income Taxes

Income taxes are the responsibility of the partners and are not reflected in these financial statements.

(m)Debt Issuance costs

Costs

Costs related to the issuance of debt are deferred and amortized using the effective-interest rate method over the term of the related debt.

The Partnership amortizes premiums and discounts incurred in connection with the issuance of debt consistent with the terms of the respective debt instrument.

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Debt issuance costs are presented in the balance sheet as a direct deduction from the carrying amount of debt liabilities, consistent with debt discount or premiums.discount. In addition, amortization of debt issuance costs, premiums, and discounts are reported as part of interest expense.

(n)Fair Value Measurements
For cash and cash equivalents, receivables, accounts payable and certain accrued expenses, the carrying amount approximates fair value due to the short maturities of these instruments. For long-term debt instruments, fair value is estimated based upon market values (if applicable) or on the current interest rates available to the Partnership for debt with similar terms and remaining maturities. Judgment is required in developing these estimates.

(3) ACCOUNTING PRONOUNCEMENTS

CHANGES

Effective January 1, 2017

Inventory

2020

Measurement of Credit Losses on Financial Instruments
In July 2015,June 2016, the FASB issued new guidance on simplifying the measurement of inventory.that significantly changes how entities measure credit losses for most financial assets and certain other financial instruments that are not measured at fair value through net income. The new guidance specifies thatamends the impairment model of financial instruments basing it on expected losses rather than incurred losses. These expected credit losses will be recognized as an entity should measure inventory withinallowance rather than as a direct write down of the scope of this update at the lower ofamortized cost and net realizable value. Net realizable value is the estimated selling price in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. Thisbasis. The new guidance was effective January 1, 2017,2020 and was applied prospectively andusing a modified retrospective approach. The adoption of this new guidance did not have a material impact on the Partnership's consolidated balance sheet.

Future Accounting Changes

Revenue from Contracts with Customers

In 2014, the FASB issued new guidance on revenue from contracts with customers. Current guidance allows for revenue recognition when certain criteria are met. The new guidance requires that an entity recognizes revenue with a five step model. This model is used to depict the transfer of promised goods or services to customers in an amount that reflects the total consideration to which the company expects to be entitled, during the term of the contract, in exchange for those goods or services. Partnership’s financial statements.


(4) COMMITMENTS AND CONTINGENCIES
(a)Contingencies
The Partnership will adoptis subject to various legal proceedings in the new standard on the effective dateordinary course of January 1, 2018. There are two methods in which the new standard can be adopted: (1)business. The accounting for contingencies covers a full retrospective approach with restatementvariety of all prior periods presented, or (2) a modified retrospective approach with a cumulative-effect adjustment as of the date of adoption.business activities, including contingencies for legal and environmental liabilities. The Partnership will adoptaccrues for these contingencies when the guidance using the modified retrospective approach with the cumulative-effect of the adjustment recognized at the date of adoption, subject to allowable and elected practical expedients.

The Partnershipassessments indicate that it is probable that a liability has identified all existing customer contracts that are within the scope of the new guidance. The Partnership has completed its analysis and has not identified any material differences in the amount and timing of revenue recognition. The Partnership will not require a cumulative-effect adjustment to opening partners' equity on January 1, 2018.

Although revenuesbeen incurred or an asset will not be materially impacted by the new guidance, therecovered, and an amount can be reasonably estimated in accordance with ASC 450, Contingencies. The Partnership will be required to add significant disclosures basedbases these estimates on the prescribed requirements. These new disclosures will include information regarding the significant judgments used in evaluating when and how revenue is recognized and information related to contract assets and deferred revenues. In addition, the new guidance requires that the Partnership's revenue recognition policy disclosure includes additional detail regarding the various performance obligationscurrently available facts and the nature, amount, timing and estimates of revenuethe ultimate outcomes or resolution. Actual results may vary from estimates resulting in an impact, positive or negative, on results of operations and cash flows generated from contracts with customers. The Partnership has addressed system and process changes necessary to compile the information to meet the recognition and disclosure requirements of the new guidance.

Leases

In February 2016, the FASB issued new guidance on the accounting for leases. The new guidance amends the definition of a lease requiring the customer to have both (1) the right to obtain substantially all of the economic benefits from the use of the asset and (2) the right to direct the use of the asset in order for the arrangement to qualify as a lease. The new guidance also establishes a right-of-use (ROU) model that requires a lessee to recognize a ROU asset and corresponding lease liability on the balance sheet for all leases with a term longer than 12 months. Leases will be classified as finance or operating, with classification affecting the pattern and classification of expense recognition in the income statement. The new guidance does not make extensive changes to lessor accounting.

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The new guidance is effective on January 1, 2019, with early adoption permitted. A modified retrospective transition approach is required for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements, with certain practical expedients available.flows. The Partnership is continuing to identify and analyze existing lease agreements to determinenot aware of any contingent liabilities that would have a material adverse effect on the effectPartnership’s financial condition, results of adoption of the new guidance on its consolidated financial statements. operations, or cash flows.

(b)Legal Proceedings
The Partnership is also addressing system and process changes necessary to compile the information to meet the recognition and disclosure requirementsnot a party in any material legal proceedings as of the new guidance. The Partnership continues to monitor and analyze additional guidance and clarification provided by FASB.

(4)    TAX REFORM IMPACT

On December 22, 2017, the President of the United States signed into law H.R. 1 (the Tax Cuts and Jobs Act). This legislation provides for major changes to U.S. corporate federal tax law, including a reduction in the U.S. corporate tax rate to 21 percent from 35 percent. As a limited partnership, the Partnership is a non-taxable pass through entity and income taxes owed as a result of the Partnership's earnings are the responsibility of each partner, therefore no amounts have been recorded in the Partnership's financial statements as a result of the Tax Cuts and Jobs Act.

31, 2020.

(c)Environmental Matters
The Partnership is regulatednot aware of any material contingent liabilities with respect to compliance with applicable environmental laws and regulations.
(d)Rights-of-Way Agreements with Native American Tribes
The majority of the land on which the Partnership operates is leased pursuant to easements, rights-of-way and other land use rights from individual landowners, Native American tribes, governmental authorities and other third parties, the majority of which are perpetual and obtained through agreement with land owners or legal process, if necessary. Certain rights, however, are subject to renewal and, with respect to tribal land held in trust by the FERC, which approves its rates,Bureau of Indian Affairs (BIA), approval by the most recentapplicable tribal governing authorities and the BIA.
During the second quarter of which were established through2018, rights-of-way expired for approximately 7.6 miles of the Partnership’s pipeline system on tribal land located within the Fond du Lac Reservation and Leech Lake Reservation in Minnesota and the Bad River Reservation in Wisconsin. As a negotiated settlement that did not ascribe any specific costresult, beginning the second quarter of service elements2018, the Partnership started accruing the estimated costs and associated liability related to income taxes. these pending agreements.
While the FERC also evaluatesPartnership has progressed on the Partnership's rate of return on an overall cost-of-service basis, they provide for a recovery ofrenewal process, the Partnership's ultimate taxable owners' income tax expense and related balance sheet accounts as components of the maximum recourse rates that may be charged to customers. As a non-taxable pass through entity, the Partnership does not recognize income tax expense nor has it established deferred income tax assets or liabilities. Income tax related expenses, benefits, assets, and liabilities attributable to regulated operations are the responsibility of the ultimate taxable owners of the Partnership and any adjustment to income tax accounts following the Tax Cuts and Jobs Act must be evaluated by those owners.

The Partnership cannot predict the impact; if any,full outcome of lower U.S. corporate tax rates on its future revenues.these negotiations. If in the future the FERC were to require a change in the Partnership's maximum recourse rates related to the change in U.S. corporate tax rate, the Partnership expects rates would be revised through future rate proceedings or other regulatory action.

At December 31, 2017, the Partnership considers its assessment of the impact of the Tax Cuts and Jobs Act to be its best interpretation of available guidance. Should additional guidance on the impact of the Tax Cuts and Jobs Act on non-taxable partnerships be provided by regulatory, tax and accounting authorities or other sources in the future, the Partnership will review the approach used and adjust as appropriate.

(5)    COMMITMENTS AND CONTINGENCIES

(a)    Legal Proceedings

On October 29, 2009, the Partnership filed suit in the U.S. District Court, District of Minnesota, against Essar Minnesota LLC (Essar Minnesota) and certain Foreign Essar Affiliates (collectively, Essar) for breach of its monthly payment obligation under its transportation services agreement with the Partnership. The Partnership sought to recover approximately $33 million for past and future payments due under the agreement. On September 16, 2015, following a jury trial, the federal district court judge entered a judgment in the amount of $32.9 million in favor of the Partnership. On September 20, 2015, Essar appealed the decision to the United States Court of Appeals for the Eighth Circuit (Eighth Circuit) based on an allegation of improper jurisdiction and a number of other rulings by the federal district judge. Essar was required to post a performance bond for the full value of the judgment pending appeal. The Eighth Circuit heard the appeal on October 20, 2016. A decision on the appeal was received in December 2016 and the Eighth Circuit vacated the Partnership' judgment against Essar finding that there was no federal jurisdiction. The Partnership filed a Request for Rehearing with the Eighth Circuit and it was denied in January 2017. Before the Circuit Court issued its decision, Essar Minnesota filed for bankruptcy in July 2016. The Foreign Essar Affiliates have not filed for bankruptcy. Following the Circuit Court's decision, the performance bond was released into the bankruptcy court proceedings. The Partnership filed a claim against Essar Minnesota in the bankruptcy court and its case against the Foreign Essar Affiliates in Minnesota state court remains pending. In April 2017, after The Partnership agreement with creditors on an allowed claim, the bankruptcy court approved the Partnership's claim in the amount of $31.5 million. On May 20, 2017, the federal district court awarded Essar Minnesota approximately $1.2 million for costs, including recovery of the performance bond premium, to be paid by the Partnership. The Partnership filed a motion with the bankruptcy court to offset the $1.2 million award of costs against its claim against Essar Minnesota in the bankruptcy proceeding but was unsuccessful. As a result, in November 2017, the Partnership accrued the $1.2 million costs in relationship to the claim.

The Partnership is unable to estimateobtain new easements or rights-of-way across all or a portion of the timingtribal lands at reasonable rates, or at all, the extentPartnership may be required to whichacquire the necessary rights at significant cost or remove and re-route portions of the pipeline at significant capital costs and disruption to operations that could have a material adverse effect on its claim willfinancial condition, results of operations and cash flows.

(e)Regulatory Matters
The FERC regulates and charges for transportation of natural gas in interstate commerce. Natural gas companies may not charge rates that have been determined to be recoverableunjust and unreasonable by the FERC. Generally, rates for interstate pipelines are based on the cost of service, including recovery of and a return on the pipeline's actual prudent historical cost investment. The
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rates and terms and conditions for service are found in the bankruptcy proceedings; therefore, did not recognize any accrualeach pipeline's FERC-approved tariff. Under its tariff, an interstate pipeline is allowed to charge for its outstanding legal matters at December 31, 2017.

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(b)    Regulatory Matters

ANR contracts

Effective November 1, 2014,services on the Partnership executed contracts with an affiliate, ANR Pipeline Company (ANR),basis of stated transportation rates. Transportation rates are established periodically in FERC proceedings known as rate cases. The tariff also allows the interstate pipeline to provide firm service in Michiganservices under negotiated and Wisconsin. These contracts were at the maximum FERC authorized rate and were intended to replace historical contracts. On December 3, 2014, the FERC accepted and suspended the Partnership's tariff records to become effective May 3, 2015, subject to refund. On February 2, 2015, FERC issued an Order granting a rehearing and clarification request submitted by thediscounted rates.


The Partnership which allowed additional time for FERC to consider the Partnership's request. Following extensive discussions with numerous shippers and other stakeholders, on April 20, 2015, ANR filedoperates under a settlement withapproved by FERC that included an agreement by ANR to pay the Partnership the difference between the historical and maximum rates (ANR Settlement). The Partnership provided service to ANR under multiple service agreements and rates through May 3, 2015 when the Partnership's tariff records became effective and subject to refund. The Partnership deferred approximately $9.4 million of revenue related to services performed in 2014 and approximately $13.9 million of additional revenue related to services performed through May 3, 2015 under such agreements. On October 15, 2015, FERC accepted and approved the ANR Settlement. As a result, the Partnership recognized the deferred transportation revenue of approximately $23.3 million in the fourth quarter of 2015.

2017 Rate case

On October 30, 2017, the Partnership filed a rate settlement with FERC to satisfy its obligations from its 2013 rate settlement for new rates to be in effect by January 1, 2018 (2017 Settlement). The 2017 Settlement if approved by FERC, will decrease the Partnership's maximum transportation rates by 27 percent beginning October 1, 2017. The 2017 Settlement doesdid not contain anya moratorium and theeliminated its revenue sharing mechanism with customers. The Partnership will be

is required to file for new rates no later than March 31, 2022, with new rates to be effective October 1, 2022.

Under Additionally, the terms of the 2017 Settlement, the revenue sharing mechanism was eliminated (refer to Note 2(j)). The Partnership'sPartnership’s annual depreciation rates remain

materially unchanged but for regulatory purposes, the Partnership shallis required to reflect a negative salvage at an annual
rate of 0.15% of transmission plant. Additionally, beginning October

Effective February 1, 2017, the Partnership was still charging customers rates in effect prior2019, FERC approved an additional 2 percent rate reduction to the 2017 Settlement but was only recognizing revenue upapproved rates,
and eliminated its tax allowance and ADIT liability from rate base pursuant to the amountPartnership’s filing of a one-time reporting requirement, designated as FERC Form 501-G related to the rate effect of the new ratesTax Cuts and Jobs Act (2017 Tax Act). On May 11, 2020, FERC terminated the Partnership's 501-G proceeding and ruled that the Partnership had complied with the FERC Form No. 501-G reporting requirement. Additionally, FERC also stated that rate reductions provided for in its 2017 settlement and the 2017 Settlement. The difference between these two amounts was recognized2.0% rate reduction as described above have provided substantial rate relief for the Partnership's customers and as a provisionresult, FERC will not exercise its right for rate refundan investigation to determine if the Partnership is over-recovering on the balance sheet.

(c)    its current tariff rates.

(f)Other Commercial Commitments

The Partnership has easements or rights-of-way arrangements from landowners permitting the use of land for the construction and operation of the Partnership'sPartnership’s pipeline system. Currently, the Partnership's obligations under these easementsThe Partnership’s future minimum payments on its rights-of-way commitments are not material to its results of operations. Certain arrangements with the Native American groups expire in 2018 and the Partnership is currently negotiating to renew these agreements.

(6)as follows:

Year EndingRights-of-Way
(In thousands)
202164 
202266 
202367 
202470 
202572 
Thereafter1,070 
$1,409 


(5) LONG-TERM DEBT

The Partnership'sPartnership’s outstanding long-term debt consisted of the following at December 31:


(In thousands)
 
2017
 
2016
 

6.73% series Senior Notes due 2016 to 2018 $9,000 18,000 
9.09% series Senior Notes due 2016 to 2021 40,000 50,000 
6.95% series Senior Notes due 2019 to 2028 110,000 110,000 
8.08% series Senior Notes due 2021 to 2030 100,000 100,000 

  259,000 278,000 
Less current maturities 19,000 19,000 

 Total long-term debt less current maturities $240,000 259,000 

Year Ending20202019
(In thousands)
9.09% series Senior Notes due 2016 to 2021$10,000 20,000 
6.95% series Senior Notes due 2019 to 202888,000 99,000 
8.08% series Senior Notes due 2021 to 2030100,000 100,000 
Total198,000 219,000 
Less: Unamortized debt issuance costs152 183 
Less: Current maturities of long-term debt31,000 21,000 
Total long-term debt, net$166,848 197,817 

The aggregate annual required repayment ofPartnership’s long-term debt is $19.0 million for 2018, $21.0 million for each year 2019 throughrepayments consisted of the following at December 31, 2020 and $31.0 million for 2021. Aggregate required repayments(in thousands of long-term debt thereafter total $167.0 million.

dollars):

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Year Ending
202131,000 
202221,000 
202321,000 
202421,000 
202521,000 
Thereafter83,000 
$198,000 
The Partnership is required to comply with certain financial, operational, and legal covenants. Under the most restrictive covenants in the Senior NoteNotes Agreements, approximately $139.5$106.6 million of partners'partners’ capital was restricted as to distributions as of December 31, 2017.2020. As of December 31, 20172020, Partnership was in compliance with all of its financial covenants.

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(7)


(6) FAIR VALUE MEASUREMENTS

(a)Fair Value Hierarchy

Under ASC 820,Fair Value Measurement, fair value measurements are characterized in one of three levels based upon the input used to arrive at the measurement. The three levels of the fair value hierarchy are as follows:

Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the Partnership has the ability to access at the measurement date.

Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly.

Level 3 inputs are unobservable inputs for the asset or liability.

When appropriate, valuations are adjusted for various factors including credit considerations. Such adjustments are generally based on available market evidence. In the absence of such evidence, management'smanagement’s best estimate is used.

(b)Fair Value of Financial Instruments

The following table presents the carrying amounts and estimated fair values of the Partnership's financial instruments at December 31, 2017 and 2016. The fair value of a financial instrument is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.

The following methods and assumptions were used to estimate the fair value of each class of financial instruments measured on a recurring basis:

Cash and cash equivalents – 

The carrying amountvalue of cash and cash equivalents, approximatesaccrued interest, all current receivable and payable accounts, except for natural gas imbalances are classified as Level 1 in fair value due tohierarchy. Accordingly, the carrying values approximate their fair values because of the short maturity or duration of these investments.

Demand loaninstruments. The Partnership’s natural gas imbalances, which are reported as part of accounts receivable, – The carrying amount of the demand loan receivable approximates fair value due to the short maturity of these investments.

Long-term debt – The fair value of senior notes was estimated based on quoted market prices for the same or similar debt instruments with similar termsaccounts payable and remaining maturities, which isrelated party accounts, are classified as a Level 2 in the "Fair“Fair Value Hierarchy", whereHierarchy,” as the fair value is determined by using valuation techniques that refer toapproach includes quoted prices in the market index and observable market data. The Partnership presently intends to maintain the current schedule of maturitiesvolumes for the notes, which will result in no gains or losses on its repayment. At December 31, 2017 the carrying value of the long term debt is $259 million and the fair value amount is $335 million. At December 31, 2016 the carrying value of the long term debt was $278 million and the fair value amount was $354 million.

(c)    Other Recurring Fair Value of Financial Instruments

The following table presents the carrying amounts which equal fair values of other items measured and recorded at fair value on a recurring basis as of December 31, 2017 and 2016:

 
 
2017

 
2016

 

(In thousands)

 
Carrying
amount

 
Fair
value

 
Carrying
amount

 
Fair
value

 

Affiliate natural gas imbalance asset $325 325 4,366 4,366 
Natural gas imbalance asset $343 343 322 322 
Affiliate natural gas imbalance liability $1,796 1,796 12 12 
Natural gas imbalance liability $3,089 3,089 3,049 3,049 

Natural Gas Imbalances –imbalance. Natural gas imbalances represent the difference between the amount of natural gas delivered to or received from a pipeline system and the amount of natural gas scheduled to be delivered or received at current market prices. We valueThe Partnership values these imbalances by applying the difference between the measured quantities of natural gas delivered to or received from our shippers and operators to the current Emerson Viking GL index price. We have classifiedFor the year ended December 31, 2020, the total estimated fair value of our third party natural gas imbalance was a net payable of approximately $1.1 million. (2019- net payable of $1.2 million). For the year ended December 31, 2020, the total estimated fair value of our related party natural gas imbalance was a net payable of approximately $0.4 million. (2019- net receivable of $1.3 million).

For the year ended December 31, 2020, the fair value of natural gas imbalancesthe Partnership’s long term debt was $277 million (2019-$287 million). The fair value was estimated based on quoted market prices for the same or similar debt instruments with similar terms and remaining maturities, which is classified as a Level 2 in the "Fair“Fair Value Hierarchy"Hierarchy”, aswhere the fair value is determined by using valuation approach includes quoted prices in thetechniques that refer to observable market index and observable volumes for the imbalance.

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(8)data.


(7) TRANSACTIONS WITH AFFILIATED COMPANIES

RELATED PARTIES

(a)Cash Management Program

The Partnership participates in TransCanada'sTC Energy’s cash management program, which matches short-term cash surpluses and needs of participating affiliates,related parties, thus minimizing total borrowings from outside sources. Monies advanced under the program are considered loans, accruing interest and repayable on demand. The Partnership receives interest on monies advanced to TransCanadaTC Energy at the rate of interest earned by TransCanadaTC Energy on its short-term cash investments. The Partnership pays interest on monies advanced from TransCanadaTC Energy based on TransCanada'sTC Energy’s short-term borrowing costs. For the years ended December 31, 2020, 2019 and 2018, the net interest income on this arrangement is immaterial. At December 31, 20172020 and 2016,2019, the Partnership had a demand loan receivable from TransCanadaTC Energy of $64.0$26.9 million and $27.1$34.3 million, respectively.

respectively, in which the net activity is treated as investing activity on the Cash Flow Statements in accordance with ASC 230 Statement of Cash Flows.

(b)    AffiliateRelated Party Revenues and Expenses

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The Partnership earns significant transportation revenues from TransCanadaTC Energy and its affiliatesrelated parties under contracts, which provide for negotiated, discounted and maximum recourse rates. The contracts are on the same terms as would be available to other shippers and the substantial majority of the Partnerships' affiliatedPartnership’s related party revenue is derived from both short-haul and long-haul transportation services

services.

Pursuant to the Partnership'sPartnership’s Operating Agreement, day-to-day operation of partnership activities is the responsibility of the Company. The Partnership is charged by the Company and affiliatesrelated parties for services such as legal, tax, treasury, human resources, other administrative functions, and for other costs incurred on its behalf. These include, but are not limited to, employee benefit costs and property and liability insurance costs. These costs are based on direct assignment to the extent practicable, or by using allocation methods that are reasonable reflections of the utilization of services provided to or for the benefits received by the Partnership. In addition, the Partnership charges rent to affiliates for use of office space in Troy, Michigan.

The following table shows revenues and charges from the Partnerships' affiliatesPartnership’s related parties for the years ended December 31:


(In thousands)
 
2017
 
2016
 
2015
 

Transportation revenues from affiliates $130,165 127,932 125,296 
Rental revenue from affiliates 1,556 1,680 1,803 
Costs charged from affiliates 35,381 30,100 30,022 
*
Transportation revenues
202020192018
(In thousands)
Transportation revenues from related parties:
    TC Energy's Canadian Mainline (Canadian Mainline) (a)
$122,637 123,862 124,359 
    ANR Pipeline Company (ANR)51,887 51,419 54,007 
Cost recovery from related parties(b)
 740 1,332 
Capital and operating costs charged by TC Energy's subsidiaries66,136 47,421 43,737 
Impact on the Partnership's net income35,504 42,241 40,434 
(a)Includes reservation revenue amounting to $74.8 million in 2020 (2019- $75.8 million and 2018- $75.8 million) related to significant contract described immediately below.
(b)Cost recovery from affiliates representrelated parties represents the amount recognized by the Partnership before any allowance on revenue sharing and provision for rate refund, which represent 57%, 68% and 70%,Partnership’s recovery of a portion of the Partnership's total revenuescosts of the facility it owns by charging its related parties for the year ended December 31, 2017, 2016 and 2015, respectively.

On April 24, 2017, Great Lakes reached an agreement on the termsuse of office space in Troy, Michigan. The building in Troy, Michigan was sold in August 2019 for a newgain of approximately $780 thousand.


The Partnership has a long-term transportation capacity contractagreement with its affiliate, TransCanada. The contract, which was subject to Canada's National Energy Board (NEB) approval, isCanadian Mainline, a related party, that commenced on November 1, 2017 for a term of 10 years andten-year period that allows TransCanada the abilityTC Energy to transport up to 0.711 billion of cubic feet of natural gas per day on the Great Lakes system from the Manitoba/U.S. border to the U.S. border near Dawn Ontario. On September 21, 2017, TransCanada received approval from the NEB and as a result, thisday. This contract, commenced on November 1, 2017. The Partnership recognized $13.0 million in transportation revenue related to this contract in 2017. This contractwhich contains volume reduction options up to full contract quantity beginning in year three.

three, was a direct benefit from TC Energy’s long-term fixed price service on its Canadian Mainline that was launched in 2017. On November 20, 2020, this contract was revised. Effective November 1, 2021 the original contract rate will be reduced with no changes in the contracted volume. Additionally, after November 20, 2020, the Canadian Mainline shall have the right to reduce the contracted volume or terminate the full contract, effective November 1st of the applicable year, provided that 349 days’ prior written notice has been given to the Partnership. As of February 22, 2021, no further revisions to this contract have been made.


In 2018, the Partnership executed long-term transportation capacity contracts with ANR, a related party, in anticipation of specific possible future needs. The original total contract value of these contracts was approximately $1.3 billion over a 15-year period. These contracts were subject to certain conditions and provisions, including a reduction option up to the full contract quantity if exercised up to certain date. During the first quarter of 2020, several amendments were made to these contracts and ANR exercised the right to terminate a significant portion of the contracts amounting to approximately $1.1 billion. The remaining maximum rate contract, which has a total capacity of approximately 168,000 Dth/Day and total contract value of $182 million over a term of 20 years, is expected to begin in late 2022. The contract contains reduction options (i) at any time on or before October 1, 2022 for any reason and (ii) at any time, if ANR is not able to secure the required regulatory approval related to its anticipated expansion projects. Any remaining unsubscribed capacity on the Partnership will be available for contracting in response to developing marketing conditions. In the first quarter of 2021, the ANR project underpinning this contract with the Partnership, has been modified to reflect revised ANR shipper commitments. ANR has not exercised its contract reduction rights as a result of the revised shipper commitments on this project. In the event of a contract reduction, the remaining unsubscribed capacity on the Partnership will be available for contracting.

On August 1, 2020, the Partnership entered into a $24.9 million purchase agreement with a TC Energy related party to purchase internally developed customer-facing commercial natural gas transmission IT application that maintains and manages customer contracts, natural gas capacity release, customer nominations, metering and billings. The purchase price was included in the "Costs charged by TC Energy's subsidiaries" tabular summary above and reported as Property, plant and equipment in the Balance Sheet. Prior to the transaction close, the Partnership paid the related party for the use of this system and the costs are included in the "Impact on the Partnership's net income" tabular summary above.

(8) REVENUES
(a)Disaggregation of Revenues
For the year ended December 31, 2020, 2019 and 2018, effectively all the Partnership’s revenues were from capacity arrangements and transportation contracts with customers as discussed under Note 2- Significant Accounting Policies.
TC PipeLines, LP Annual Report 2020F-55

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(b)Contract Balances
The Partnership’s contract balances consist primarily of receivables from contracts with customers reported under accounts receivable in the balance sheet. Additionally, our accounts receivable represents the Partnership’s unconditional right to consideration for services completed which includes billed and unbilled accounts.
(c)Right to invoice practical expedient
In the application of the right to invoice practical expedient, the Partnership’s revenues from regulated capacity arrangements are recognized based on rates specified in the contract. Therefore, the amount invoiced, which includes the capacity contracted and variable volume of natural gas transported, corresponds directly to the value the customer received. These revenues are recognized monthly once the Partnership’s performance obligation to provide capacity has been satisfied.

(9) DISTRIBUTIONS

The Partnership'sPartnership’s distribution policy generally results in a quarterly cash distribution equal to 100%100 percent of distributable cash flow based upon earnings before income taxes, depreciation, AFUDC less capital expenditures and debt repayments not funded with cash calls to its partners. The resulting distribution amount and timing are subject to Management Committee modification and approval after considering business risks as well as ensuring minimum cash balances, equity balances, and ratios are maintained.

On January 10, 2018,13, 2021, the Management Committee of the Partnership declared a cash distribution in the amount of $19.5$23.3 million to the partners. The distribution was paid on February 1, 2018.

January 29, 2021.


(10) SUBSEQUENT EVENTS

Subsequent events have been assessed through February 16, 2018,22, 2021, which is the date the financial statements were issued, and wethe Partnership concluded there were no events or transactions during this period that would require recognition or disclosure in the financial statements other than those already reflected.

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 2020