Organization and Basis of Consolidation and Presentation Organization Plains All American Pipeline, L.P. (PAA) is a Delaware limited partnership formed in 1998. Our operations are conducted directly and indirectly through our primary operating subsidiaries. As used in this Form 10-K and unless the context indicates otherwise, the terms Partnership, we, us, our, ours and similar terms refer to PAA and its subsidiaries. We own and operate midstream energy infrastructure and provide logistics services primarily for crude oil, natural gas liquids (NGL) and natural gas. We own an extensive network of pipeline transportation, terminalling, storage and gathering assets in key crude oil and NGL producing basins and transportation corridors and at major market hubs in the United States and Canada. Our business activities are conducted through three operating segments: Transportation, Facilities and Supply and Logistics. See Note 21 for further discussion of our operating segments. Our non-economic general partner interest is held by PAA GP LLC (PAA GP), a Delaware limited liability company, whose sole member is Plains AAP, L.P. (AAP), a Delaware limited partnership. In addition to its ownership of PAA GP, as of December 31, 2019, AAP also owned a limited partner interest in us through its ownership of approximately 249.6 million of our common units (approximately 31% of our total outstanding common units and Series A preferred units combined). Plains All American GP LLC (GP LLC), a Delaware limited liability company, is AAPs general partner. Plains GP Holdings, L.P. (PAGP) is the sole and managing member of GP LLC, and, at December 31, 2019, owned an approximate 73% limited partner interest in AAP. PAA GP Holdings LLC (PAGP GP) is the general partner of PAGP. As the sole member of GP LLC, PAGP has responsibility for conducting our business and managing our operations; however, the board of directors of PAGP GP has ultimate responsibility for managing the business and affairs of PAGP, AAP and us. GP LLC employs our domestic officers and personnel; our Canadian officers and personnel are employed by our subsidiary, Plains Midstream Canada ULC. References to the PAGP Entities include PAGP GP, PAGP, GP LLC, AAP and PAA GP. References to our general partner, as the context requires, include any or all of the PAGP Entities. References to the Plains Entities include us, our subsidiaries and the PAGP Entities. Definitions Additional defined terms are used in the following notes and shall have the meanings indicated below: AOCI = Accumulated other comprehensive income/(loss) ASC = Accounting Standards Codification ASU = Accounting Standards Update Bcf = Billion cubic feet CAD = Canadian dollar CODM = Chief Operating Decision Maker DERs = Distribution equivalent rights EBITDA = Earnings before interest, taxes, depreciation and amortization EPA = United States Environmental Protection Agency FASB = Financial Accounting Standards Board GAAP = Generally accepted accounting principles in the United States ICE = Intercontinental Exchange ISDA = International Swaps and Derivatives Association LIBOR = London Interbank Offered Rate LTIP = Long-term incentive plan Mcf = Thousand cubic feet MMbls = Million barrels MLP = Master limited partnership NGL = Natural gas liquids, including ethane, propane and butane NYMEX = New York Mercantile Exchange Oxy = Occidental Petroleum Corporation or its subsidiaries SEC = United States Securities and Exchange Commission TWh = Terawatt hour USD = United States dollar WTI = West Texas Intermediate Basis of Consolidation and Presentation The accompanying financial statements and related notes present and discuss our consolidated financial position as of December 31, 2019 and 2018, and the consolidated results of our operations, cash flows, changes in partners capital, comprehensive income and changes in accumulated other comprehensive income/(loss) for the years ended December 31, 2019, 2018 and 2017. All significant intercompany transactions have been eliminated in consolidation, and certain reclassifications have been made to information from previous years to conform to the current presentation. The accompanying consolidated financial statements include the accounts of PAA and all of its wholly owned subsidiaries and those entities that it controls. Investments in entities over which we have significant influence but not control are accounted for by the equity method. We apply proportionate consolidation for pipelines and other assets in which we own undivided joint interests. Subsequent events have been evaluated through the financial statements issuance date and have been included in the following footnotes where applicable.