10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

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

For the quarterly period ended March 31, 2017

or

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

For the transition period from _____________ to _____________

Commission file number 1-34831

WILLIAMS PARTNERS L.P.

(Exact name of registrant as specified in its charter)

DELAWARE	20-2485124
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)
ONE WILLIAMS CENTER
TULSA, OKLAHOMA	74172-0172
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code: (918) 573-2000

NO CHANGE

(Former name, former address and former fiscal year, if changed since last report)

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 þ   No ¨

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 þ   No ¨

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

Large accelerated filer þ	Accelerated filer ¨	Non-accelerated filer ¨	Smaller reporting company ¨	Emerging growth company ¨
		(Do not check if a smaller reporting company)

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. ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ¨   No þ

The registrant had 955,457,613 common units and 17,065,816 Class B units outstanding as of April 28, 2017.

Williams Partners L.P.

Index

Part I. Financial Information	Page
Item 1. Financial Statements
Consolidated Statement of Comprehensive Income (Loss) – Three Months Ended March 31, 2017 and 2016	6
Consolidated Balance Sheet – March 31, 2017 and December 31, 2016	7
Consolidated Statement of Changes in Equity – Three Months Ended March 31, 2017	8
Consolidated Statement of Cash Flows – Three Months Ended March 31, 2017 and 2016	9
Notes to Consolidated Financial Statements	10
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations	26
Item 3. Quantitative and Qualitative Disclosures About Market Risk	44
Item 4. Controls and Procedures	45
Part II. Other Information	45
Item 1. Legal Proceedings	45
Item 6. Exhibits	46

The reports, filings, and other public announcements of Williams Partners L.P. (WPZ) may contain or incorporate by reference statements that do not directly or exclusively relate to historical facts. Such statements are “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended (Securities Act) and Section 21E of the Securities Exchange Act of 1934, as amended (Exchange Act). These forward-looking statements relate to anticipated financial performance, management’s plans, and objectives for future operations, business prospects, outcome of regulatory proceedings, market conditions, and other matters.

All statements, other than statements of historical facts, included in this report that address activities, events or developments that we expect, believe or anticipate will exist or may occur in the future, are forward-looking statements. Forward-looking statements can be identified by various forms of words such as “anticipates,” “believes,” “seeks,” “could,” “may,” “should,” “continues,” “estimates,” “expects,” “forecasts,” “intends,” “might,” “goals,” “objectives,” “targets,” “planned,” “potential,” “projects,” “scheduled,” “will,” “assumes,” “guidance,” “outlook,” “in service date,” or other similar expressions. These forward-looking statements are based on management’s beliefs and assumptions and on information currently available to management and include, among others, statements regarding:

• Levels of cash distributions with respect to limited partner interests;

• Our and our affiliates’ future credit ratings;

• Amounts and nature of future capital expenditures;

• Expansion and growth of our business and operations;

• Financial condition and liquidity;

• Business strategy;

• Cash flow from operations or results of operations;

1

• Seasonality of certain business components;

• Natural gas, natural gas liquids, and olefins prices, supply, and demand;

• Demand for our services.

Forward-looking statements are based on numerous assumptions, uncertainties and risks that could cause future events or results to be materially different from those stated or implied in this report. Many of the factors that will determine these results are beyond our ability to control or predict. Specific factors that could cause actual results to differ from results contemplated by the forward-looking statements include, among others, the following:

• Whether we will produce sufficient cash flows to provide the level of cash distributions that Williams expects;

• Whether we elect to pay expected levels of cash distributions;

• Whether we will be able to effectively execute our financing plan including the receipt of anticipated levels of proceeds from planned asset sales;

• Whether Williams will be able to effectively manage the transition in its board of directors and management as well as successfully execute its business restructuring;

• Availability of supplies, including lower than anticipated volumes from third parties served by our midstream business, and market demand;

• Volatility of pricing including the effect of lower than anticipated energy commodity prices and margins;

• Inflation, interest rates, and general economic conditions (including future disruptions and volatility in the global credit markets and the impact of these events on customers and suppliers);

• The strength and financial resources of our competitors and the effects of competition;

• Whether we are able to successfully identify, evaluate, and timely execute our capital projects and other investment opportunities in accordance with our forecasted capital expenditures budget;

• Our ability to successfully expand our facilities and operations;

• Development of alternative energy sources;

• The impact of operational and developmental hazards and unforeseen interruptions and the availability of adequate insurance coverage;

• The impact of existing and future laws, regulations, the regulatory environment, environmental liabilities, and litigation, as well as our ability to obtain permits and achieve favorable rate proceeding outcomes;

• Williams’ costs and funding obligations for defined benefit pension plans and other postretirement benefit plans;

• Our allocated costs for defined benefit pension plans and other postretirement benefit plans sponsored by our affiliates;

2

• Changes in maintenance and construction costs;

• Changes in the current geopolitical situation;

• Our exposure to the credit risk of our customers and counterparties;

• Risks related to financing, including restrictions stemming from debt agreements, future changes in credit ratings as determined by nationally-recognized credit rating agencies and the availability and cost of capital;

• The amount of cash distributions from and capital requirements of our investments and joint ventures in which we participate;

• Risks associated with weather and natural phenomena, including climate conditions and physical damage to our facilities;

• Acts of terrorism, including cybersecurity threats, and related disruptions;

• Additional risks described in our filings with the Securities and Exchange Commission (SEC).

Given the uncertainties and risk factors that could cause our actual results to differ materially from those contained in any forward-looking statement, we caution investors not to unduly rely on our forward-looking statements. We disclaim any obligations to and do not intend to update the above list or announce publicly the result of any revisions to any of the forward-looking statements to reflect future events or developments.

In addition to causing our actual results to differ, the factors listed above and referred to below may cause our intentions to change from those statements of intention set forth in this report. Such changes in our intentions may also cause our results to differ. We may change our intentions, at any time and without notice, based upon changes in such factors, our assumptions, or otherwise.

Limited partner units 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. You should carefully consider the risk factors discussed below in addition to the other information in this report. If any of the following risks were actually to occur, our business, results of operations, and financial condition could be materially adversely affected. In that case, we might not be able to pay distributions on our common units, the trading price of our common units could decline, and unitholders could lose all or part of their investment.

Because forward-looking statements involve risks and uncertainties, we caution that there are important factors, in addition to those listed above, that may cause actual results to differ materially from those contained in the forward-looking statements. For a detailed discussion of those factors, see Part I, Item 1A. Risk Factors in our Annual Report on Form 10-K filed with the SEC on February 22, 2017.

3

DEFINITIONS

The following is a listing of certain abbreviations, acronyms, and other industry terminology used throughout this Form 10-Q.

Measurements:

Barrel: One barrel of petroleum products that equals 42 U.S. gallons

Bcf : One billion cubic feet of natural gas

Bcf/d: One billion cubic feet of natural gas per day

British Thermal Unit (Btu): A unit of energy needed to raise the temperature of one pound of water by one degree

Fahrenheit

Dekatherms (Dth): A unit of energy equal to one million British thermal units

Mbbls/d: One thousand barrels per day

Mdth/d: One thousand dekatherms per day

MMcf/d: One million cubic feet per day

MMdth: One million dekatherms or approximately one trillion British thermal units

MMdth/d: One million dekatherms per day

Tbtu: One trillion British thermal units

Consolidated Entities:

Cardinal: Cardinal Gas Services, L.L.C.

Constitution: Constitution Pipeline Company, LLC

Gulfstar One: Gulfstar One LLC

Jackalope: Jackalope Gas Gathering Services, L.L.C.

Northwest Pipeline: Northwest Pipeline, LLC

Transco: Transcontinental Gas Pipe Line Company, LLC

Partially Owned Entities: Entities in whichwe do not own a 100 percent ownership interest and which, as of March 31, 2017, we account for as an equity-method investment, including principally the following:

Aux Sable: Aux Sable Liquid Products LP

Caiman II: Caiman Energy II, LLC

Discovery: Discovery Producer Services LLC

Gulfstream: Gulfstream Natural Gas System, L.L.C.

Laurel Mountain: Laurel Mountain Midstream, LLC

OPPL: Overland Pass Pipeline Company LLC

UEOM: Utica East Ohio Midstream LLC

Government and Regulatory:

EPA: Environmental Protection Agency

FERC: Federal Energy Regulatory Commission

SEC: Securities and Exchange Commission

4

Other:

Williams: The Williams Companies, Inc. and, unless the context otherwise indicates, its subsidiaries (other than Williams Partners L.P. and its subsidiaries)

GAAP: U.S. generally accepted accounting principles

Fractionation: The process by which a mixed stream of natural gas liquids is separated into constituent products, such as ethane, propane, and butane

IDR: Incentive distribution right

NGLs: Natural gas liquids; natural gas liquids result from natural gas processing and crude oil refining and are

used as petrochemical feedstocks, heating fuels, and gasoline additives, among other applications

NGL margins:NGL revenues less any applicable Btu replacement cost, plant fuel, and third-party transportation and fractionation

5

PART I – FINANCIAL INFORMATION

Williams Partners L.P.

Consolidated Statement of Comprehensive Income (Loss)

(Unaudited)

	Three Months Ended   March 31,
	2017			2016
	(Millions, except per-unit amounts)
Revenues:
Service revenues	$	1,256		$	1,226
Product sales	727			428
Total revenues	1,983			1,654
Costs and expenses:
Product costs	579			317
Operating and maintenance expenses	361			382
Depreciation and amortization expenses	433			435
Selling, general, and administrative expenses	156			181
Other (income) expense – net	4			30
Total costs and expenses	1,533			1,345
Operating income (loss)	450			309
Equity earnings (losses)	107			97
Impairment of equity-method investments (Note 8)	—			(112		)
Other investing income (loss) – net (Note 4)	271			—
Interest incurred	(221		)	(240		)
Interest capitalized	7			11
Other income (expense) – net	49			15
Income (loss) before income taxes	663			80
Provision (benefit) for income taxes	3			1
Net income (loss)	660			79
Less: Net income (loss) attributable to noncontrolling interests	26			29
Net income (loss) attributable to controlling interests	$	634		$	50
Allocation of net income (loss) for calculation of earnings per common unit:
Net income (loss) attributable to controlling interests	$	634		$	50
Allocation of net income (loss) to general partner	—			202
Allocation of net income (loss) to Class B units	11			(4		)
Allocation of net income (loss) to common units	$	623		$	(148	)
Basic earnings (loss) per common unit:
Net income (loss) per common unit	$	.68		$	(.25	)
Weighted-average number of common units outstanding (thousands)	919,944			588,562
Diluted earnings (loss) per common unit:
Net income (loss) per common unit	$	.68		$	(.25	)
Weighted-average number of common units outstanding (thousands)	920,250			588,562
Cash distributions per common unit	$	.60		$	.85
Other comprehensive income (loss):
Cash flow hedging activities:
Net unrealized gain (loss) from derivative instruments	$	4		$	—
Reclassifications into earnings of net derivative instruments (gain) loss	(1		)	—
Foreign currency translation activities:
Foreign currency translation adjustments	—			72
Other comprehensive income (loss)	3			72
Comprehensive income (loss)	663			151
Less: Comprehensive income attributable to noncontrolling interests	26			29
Comprehensive income (loss) attributable to controlling interests	$	637		$	122

See accompanying notes.

6

Williams Partners L.P.

Consolidated Balance Sheet

(Unaudited)

	March 31, 2017			December 31, 2016
	(Dollars in millions)
ASSETS
Current assets:
Cash and cash equivalents	$	625		$	145
Trade accounts and other receivables (net of allowance of $6 at March 31, 2017 and $6 at December 31, 2016)	861			926
Inventories	148			138
Assets held for sale (Note 1)	1,023			24
Other current assets and deferred charges	157			181
Total current assets	2,814			1,414
Investments	6,738			6,701
Property, plant, and equipment, at cost	37,677			38,247
Accumulated depreciation and amortization	(10,313		)	(10,226		)
Property, plant, and equipment – net	27,364			28,021
Intangible assets – net of accumulated amortization	9,569			9,662
Regulatory assets, deferred charges, and other	453			467
Total assets	$	46,938		$	46,265
LIABILITIES AND EQUITY
Current liabilities:
Accounts payable:
Trade	$	656		$	589
Affiliate	76			109
Accrued interest	170			258
Asset retirement obligations	48			61
Liabilities held for sale (Note 1)	43			—
Other accrued liabilities	881			804
Commercial paper	—			93
Long-term debt due within one year	—			785
Total current liabilities	1,874			2,699
Long-term debt	17,065			17,685
Asset retirement obligations	830			798
Deferred income tax liabilities	19			20
Regulatory liabilities, deferred income, and other	1,951			1,860
Contingent liabilities (Note 9)
Equity:
Partners’ equity:
Common units (955,455,083 and 607,064,550 units outstanding at March 31, 2017 and December 31, 2016, respectively)	22,680			18,300
Class B units (17,065,816 and 16,690,016 units outstanding at March 31, 2017 and December 31, 2016, respectively)	780			769
General partner	—			2,385
Accumulated other comprehensive income (loss)	2			(1		)
Total partners’ equity	23,462			21,453
Noncontrolling interests in consolidated subsidiaries	$	1,737		1,750
Total equity	25,199			23,203
Total liabilities and equity	$	46,938		$	46,265

See accompanying notes.

7

Williams Partners L.P.

Consolidated Statement of Changes in Equity

(Unaudited)

	Williams Partners L.P.
	Limited Partners
	Common Units			Class B Units		General Partner			Accumulated Other Comprehensive Income (Loss)			Total Partners’ Equity			Noncontrolling Interests			Total Equity
	(Millions)
Balance – December 31, 2016	$	18,300		$	769	$	2,385		$	(1	)	$	21,453		$	1,750		$	23,203
Net income (loss)	623			11		—			—			634			26			660
Other comprehensive income (loss)	—			—		—			3			3			—			3
Conversion to non-economic general partner interest (Note 1)	2,385			—		(2,385		)	—			—			—			—
Distributions to The Williams Companies, Inc. - net	(11		)	—		—			—			(11		)	—			(11		)
Sale of common units (Note 1)	2,194			—		—			—			2,194			—			2,194
Distributions to limited partners	(812		)	—		—			—			(812		)	—			(812		)
Contributions from noncontrolling interests	—			—		—			—			—			4			4
Distributions to noncontrolling interests	—			—		—			—			—			(43		)	(43		)
Other	1			—		—			—			1			—			1
Net increase (decrease) in equity	4,380			11		(2,385		)	3			2,009			(13		)	1,996
Balance – March 31, 2017	$	22,680		$	780	$	—		$	2		$	23,462		$	1,737		$	25,199

See accompanying notes.

8

Williams Partners L.P.

Consolidated Statement of Cash Flows

(Unaudited)

	Three Months Ended   March 31,
	2017			2016
	(Millions)
OPERATING ACTIVITIES:
Net income (loss)	$	660		$	79
Adjustments to reconcile to net cash provided (used) by operating activities:
Depreciation and amortization	433			435
Provision (benefit) for deferred income taxes	(1		)	—
Net (gain) loss on disposition of equity-method investments	(269		)	—
Impairment of equity-method investments	—			112
Impairment of and net (gain) loss on sale of assets and businesses	—			8
Amortization of stock-based awards	2			9
Cash provided (used) by changes in current assets and liabilities:
Accounts and notes receivable	22			298
Inventories	(30		)	(15		)
Other current assets and deferred charges	19			23
Accounts payable	38			(19		)
Accrued liabilities	(28		)	(70		)
Affiliate accounts receivable and payable – net	(32		)	(15		)
Other, including changes in noncurrent assets and liabilities	(83		)	79
Net cash provided (used) by operating activities	731			924
FINANCING ACTIVITIES:
Proceeds from (payments of) commercial paper – net	(93		)	(365		)
Proceeds from long-term debt	—			1,838
Payments of long-term debt	(1,350		)	(1,526		)
Proceeds from sales of common units	2,178			—
Contributions from general partner	—			3
Distributions paid	(796		)	(516		)
Distributions to noncontrolling interests	(43		)	(19		)
Contributions from noncontrolling interests	4			16
Distributions to The Williams Companies, Inc. – net	(11		)	—
Payments for debt issuance costs	—			(8		)
Other – net	(23		)	1
Net cash provided (used) by financing activities	(134		)	(576		)
INVESTING ACTIVITIES:
Property, plant, and equipment:
Capital expenditures (1)	(509		)	(463		)
Net proceeds from dispositions	(2		)	—
Proceeds from dispositions of equity-method investments	200			—
Purchases of and contributions to equity-method investments	(52		)	(63		)
Distributions from unconsolidated affiliates in excess of cumulative earnings	121			109
Other – net	125			98
Net cash provided (used) by investing activities	(117		)	(319		)
Increase (decrease) in cash and cash equivalents	480			29
Cash and cash equivalents at beginning of year	145			96
Cash and cash equivalents at end of period	$	625		$	125
_________
(1) Increases to property, plant, and equipment	$	(569	)	$	(498	)
Changes in related accounts payable and accrued liabilities	60			35
Capital expenditures	$	(509	)	$	(463	)

See accompanying notes.

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Williams Partners L.P.

Notes to Consolidated Financial Statements

(Unaudited)

Note 1 – General, Description of Business, and Basis of Presentation

General

Our accompanying interim consolidated financial statements do not include all the notes in our annual financial statements and, therefore, should be read in conjunction with the consolidated financial statements and notes thereto for the year ended December 31, 2016, in our Annual Report on Form 10-K. The accompanying unaudited financial statements include all normal recurring adjustments and others that, in the opinion of management, are necessary to present fairly our interim financial statements.

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates.

Unless the context clearly indicates otherwise, references in this report to “we,” “our,” “us,” or like terms refer to Williams Partners L.P. and its subsidiaries. Unless the context clearly indicates otherwise, references to “we,” “our,” and “us” include the operations in which we own interests accounted for as equity-method investments that are not consolidated in our financial statements. When we refer to our equity investees by name, we are referring exclusively to their businesses and operations.

We are a Delaware limited partnership whose common units are listed and traded on the New York Stock Exchange. WPZ GP LLC, a Delaware limited liability company wholly owned by The Williams Companies, Inc. (Williams), serves as our general partner. Our operations are located in the United States.

Financial Repositioning

In January 2017, we announced agreements with Williams, wherein Williams permanently waived the general partner’s incentive distribution rights (IDRs) and converted its 2 percent general partner interest in us to a non-economic interest in exchange for 289 million newly issued common units. Pursuant to this agreement, Williams also purchased approximately 277 thousand common units for $10 million. Additionally, Williams purchased approximately 59 million common units at a price of $36.08586 per unit in a private placement transaction. According to the terms of this agreement, following our quarterly distribution in February 2017, Williams paid additional consideration of approximately $50 million to us for these units. Following these transactions and as of March 31, 2017, Williams owns a 74 percent limited partner interest in us.

Geismar Olefins Facility Assets Held For Sale

On April 17, 2017, we announced that we agreed to sell Williams Olefins, L.L.C., a wholly owned subsidiary which owns an interest in the Geismar, Louisiana, olefins plant (Geismar Interest) for $2.1 billion in cash, subject to customary closing conditions and regulatory approvals. Upon closing of the sale, we will enter into a long-term supply and transportation agreement with the purchaser to provide feedstock to the plant via our Bayou Ethane pipeline system. We expect that the sale will close during the summer of 2017.

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Notes (Continued)

The assets and liabilities of the Geismar olefins plant are presented as held for sale as of March 31, 2017. The following table presents the carrying amounts of the major classes of assets and liabilities included as part of the Geismar disposal group, which are presented within Assets held for sale and Liabilities held for sale in the Consolidated Balance Sheet. Also included in Assets held for sale in the Consolidated Balance Sheet are $24 million of assets held for sale within the West segment unrelated to the Geismar Interest and at December 31, 2016, were previously included in Other current assets and deferred charges.

	Carrying Amount
	March 31, 2017
	(Millions)
Assets:
Current assets	$	71
Property, plant, and equipment – net	901
Other noncurrent assets	27
	$	999
Liabilities:
Current liabilities	$	42
Noncurrent liabilities	1
	$	43

The following table presents the results of operations for the Geismar disposal group.

	Three Months Ended   March 31,
	2017		2016
	(Millions)
Income (loss) before income taxes of disposal group	$	23	$	18

Description of Business

Effective January 1, 2017, we implemented organizational changes, consistent with the manner in which our chief operating decision maker evaluates performance and allocates resources. Operations previously reported within the Central segment are now generally managed and presented within the West segment. Certain businesses previously within our NGL & Petchem Services segment are now managed and presented within the West, Atlantic-Gulf, and Northeast G&P segments. As a result, beginning with the reporting of first quarter 2017, our operations are organized into the following reportable segments: Northeast G&P, Atlantic-Gulf, West, and NGL & Petchem Services. Certain other corporate activities are included in Other. Prior period segment disclosures have been recast for these segment changes.

Northeast G&P is comprised of our midstream gathering and processing businesses in the Marcellus Shale region primarily in Pennsylvania, New York, and West Virginia and the Utica Shale region of eastern Ohio, as well as a 66 percent interest in Cardinal Gas Services, L.L.C. (Cardinal) (a consolidated entity), a 62 percent equity-method investment in Utica East Ohio Midstream, LLC (UEOM), a 69 percent equity-method investment in Laurel Mountain Midstream, LLC (Laurel Mountain), a 58 percent equity-method investment in Caiman Energy II, LLC (Caiman II), and Appalachia Midstream Services, LLC, which owns equity-method investments with an approximate average 66 percent interest in multiple gathering systems in the Marcellus Shale (Appalachia Midstream Investments).

Atlantic-Gulf is comprised of our interstate natural gas pipeline, Transcontinental Gas Pipe Line Company, LLC (Transco), and significant natural gas gathering and processing and crude oil production handling and transportation assets in the Gulf Coast region, including a 51 percent interest in Gulfstar One LLC (Gulfstar One) (a consolidated entity), which is a proprietary floating production system, and various petrochemical and feedstock pipelines in the Gulf Coast region, as well as a 50 percent equity-method investment in Gulfstream Natural Gas System, L.L.C.

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Notes (Continued)

(Gulfstream), a 41 percent interest in Constitution Pipeline Company, LLC (Constitution) (a consolidated entity), which is under development, and a 60 percent equity-method investment in Discovery Producer Services LLC (Discovery).

West is comprised of our interstate natural gas pipeline, Northwest Pipeline LLC (Northwest Pipeline), and our gathering, processing, and treating operations in New Mexico, Colorado, and Wyoming, as well as the Barnett Shale region of north-central Texas, the Eagle Ford Shale region of south Texas, the Haynesville Shale region of northwest Louisiana, and the Mid-Continent region which includes the Anadarko, Arkoma, Delaware, and Permian basins. This segment also includes our NGL and natural gas marketing business, storage facilities, an undivided 50 percent interest in an NGL fractionator near Conway, Kansas, and a 50 percent equity-method investment in Overland Pass Pipeline, LLC (OPPL), as well as our previously owned 50 percent equity-method investment in the Delaware basin gas gathering system (DBJV) in the Mid-Continent region (see Note 4 – Investing Activities).

NGL & Petchem Services is comprised of our 88.5 percent undivided interest in an olefins production facility in Geismar, Louisiana (see Geismar Olefins Facility Assets Held For Sale), along with a refinery grade propylene splitter in the Gulf region, as well as the previously owned Canadian assets which included an oil sands offgas processing plant located near Fort McMurray, Alberta, and a natural gas liquid (NGL)/olefin fractionation facility at Redwater, Alberta. In September 2016, we completed the sale of our Canadian operations.

Basis of Presentation

Significant risks and uncertainties

We have announced plans to monetize assets that are not core to our strategy. As we pursue these asset monetizations, it is possible that we may incur impairments of certain equity-method investments, property, plant, and equipment, and intangible assets. Such impairments could potentially be caused by indications of fair value implied through the monetization process or, in the case of asset dispositions that are part of a broader asset group, the impact of the loss of future estimated cash flows.

Accounting standards issued but not yet adopted

In January 2017, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2017-04 “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment” (ASU 2017-04). ASU 2017-04 modifies the concept of goodwill impairment to represent the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. Under ASU 2017-04, entities will no longer be required to determine the implied fair value of goodwill by assigning the fair value of a reporting unit to its individual assets and liabilities as if that reporting unit had been acquired in a business combination. ASU 2017-04 is effective for goodwill impairment testing for interim and annual periods beginning after December 15, 2019, and requires a prospective transition. Early adoption is permitted for interim and annual goodwill impairment tests performed after January 1, 2017, and we plan to adopt this standard in 2017. Our West reportable segment has $47 million of goodwill included in Intangible assets - net of accumulated amortization in the Consolidated Balance Sheet.

In August 2016, the FASB issued ASU 2016-15 “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments” (ASU 2016-15). ASU 2016-15 provides specific guidance on eight cash flow classification issues, including debt prepayment or debt extinguishment costs and distributions received from equity method investees, to reduce diversity in practice. ASU 2016-15 is effective for interim and annual periods beginning after December 15, 2017. Early adoption is permitted. The new standard requires a retrospective transition. We are evaluating the impact of the new standard on our consolidated financial statements.

In June 2016, the FASB issued ASU 2016-13 “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (ASU 2016-13). ASU 2016-13 changes the impairment model for most financial assets and certain other instruments. For trade and other receivables, held-to-maturity debt securities, loans, and other instruments, entities will be required to use a new forward-looking “expected loss” model that generally will result in the earlier recognition of allowances for losses. The guidance also requires increased disclosures. ASU 2016-13 is effective for interim and annual periods beginning after December 15, 2019. Early adoption is permitted. The new standard requires varying transition methods for the different categories of amendments. We are evaluating the impact

12

Notes (Continued)

of the new standard on our consolidated financial statements. Although we do not expect this new standard to have a significant impact, it will impact our trade receivables as the related allowance for credit losses will be recognized earlier under the expected loss model.

In February 2016, the FASB issued ASU 2016-02 “Leases (Topic 842)” (ASU 2016-02). ASU 2016-02 establishes a comprehensive new lease accounting model. The new standard clarifies the definition of a lease, requires a dual approach to lease classification similar to current lease classifications, and causes lessees to recognize leases on the balance sheet as a lease liability with a corresponding right-of-use asset. ASU 2016-02 is effective for interim and annual periods beginning after December 15, 2018. Early adoption is permitted. The new standard requires a modified retrospective transition for capital or operating leases existing at or entered into after the beginning of the earliest comparative period presented in the financial statements. We are reviewing contracts to identify leases, particularly reviewing the applicability of this new standard to contracts involving easements/rights-of-way.

In May 2014, the FASB issued ASU 2014-09 establishing Accounting Standards Codification (ASC) Topic 606, “Revenue from Contracts with Customers” (ASC 606). ASC 606 establishes a comprehensive new revenue recognition model designed to depict the transfer of goods or services to a customer in an amount that reflects the consideration the entity expects to be entitled to receive in exchange for those goods or services and requires significantly enhanced revenue disclosures. In August 2015, the FASB issued ASU 2015-14 “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date” (ASU 2015-14). Per ASU 2015-14, the standard is effective for interim and annual reporting periods beginning after December 15, 2017. ASC 606 allows either full retrospective or modified retrospective transition and early adoption is permitted for annual periods beginning after December 15, 2016.

We continue to evaluate the impact the standard may have on our financial statements. For each revenue contract type, we are conducting a formal contract review process to evaluate the impact, if any, that the new revenue standard may have. We have substantially completed that process, but continue to evaluate our accounting for noncash consideration, which exists in contracts where we receive commodities as full or partial consideration and contracts with a significant financing component, which may exist in situations where the timing of the consideration we received varies significantly from the timing of when we provide the service. As such, we are unable to determine the potential impact upon the amount and timing of revenue recognition and related disclosures. Additionally, we have identified possible financial system and internal control changes necessary for adoption. We currently anticipate utilizing a modified retrospective transition upon the adoption of ASC 606 as of January 1, 2018.

Public Unit Exchange

On May 12, 2015, we entered into an agreement for a unit-for-stock transaction whereby Williams would have acquired all of our publicly held outstanding common units in exchange for shares of Williams’ common stock (WPZ Public Unit Exchange).

On September 28, 2015, we entered into a Termination Agreement and Release (Termination Agreement), terminating the WPZ Public Unit Exchange. Under the terms of the Termination Agreement, Williams was required to pay us a $428 million termination fee, which settled through a reduction of quarterly incentive distributions payable to Williams (such reduction not to exceed $209 million per quarter). Our November 2015, February 2016, and May 2016 distributions to Williams were reduced by $209 million, $209 million, and $10 million, respectively, related to this termination fee.

Note 2 – Variable Interest Entities

As of March 31, 2017, we consolidate the following variable interest entities (VIEs):

Gulfstar One

We own a51 percent interest in Gulfstar One, a subsidiary that, due to certain risk-sharing provisions in its customer contracts, is a VIE. Gulfstar One includes a proprietary floating-production system, Gulfstar FPS, and associated pipelines which provide production handling and gathering services in the eastern deepwater Gulf of Mexico. We are the primary beneficiary because we have the power to direct the activities that most significantly impact Gulfstar One’s economic performance.

13

Notes (Continued)

Constitution

We own a41 percent interest in Constitution, a subsidiary that, due to shipper fixed-payment commitments under its long-term firm transportation contracts, is a VIE. We are the primary beneficiary because we have the power to direct the activities that most significantly impact Constitution’s economic performance. We, as construction manager for Constitution, are responsible for constructing the proposed pipeline connecting our gathering system in Susquehanna County, Pennsylvania, to the Iroquois Gas Transmission and the Tennessee Gas Pipeline systems. The total remaining cost of the project is estimated to be approximately $691 million, which we expect will be funded with capital contributions from us and the other equity partners on a proportional basis.

In December 2014, Constitution received approval from the Federal Energy Regulatory Commission (FERC) to construct and operate its proposed pipeline. However, in April 2016, the New York State Department of Environmental Conservation (NYSDEC) denied a necessary water quality certification for the New York portion of the pipeline. We remain steadfastly committed to the project, and in May 2016, Constitution appealed the NYSDEC's denial of the water quality certification.The oral argument before the Second Circuit Court of Appeals regarding the NYSDEC’s denial of Constitution’s application for water quality certification under Section 401 of the Clean Water Act was held on November 16, 2016. We anticipate a decision from the Second Circuit Court of Appeals as early as the second quarter of 2017. In light of the NYSDEC's denial of the water quality certification and the actions taken to challenge the decision, the project in-service date is targeted as early as the second half of 2018, which assumes that the legal challenge process is satisfactorily and promptly concluded. An unfavorable resolution could result in the impairment of a significant portion of the capitalized project costs, which total $381 million on a consolidated basis at March 31, 2017, and are included within Property, plant, and equipment, at cost in the Consolidated Balance Sheet. Beginning in April 2016, we discontinued capitalization of development costs related to this project. It is also possible that we could incur certain supplier-related costs in the event of a prolonged delay or termination of the project.

Cardinal

We own a 66 percent interest in Cardinal, a subsidiary that provides gathering services for the Utica Shale region and is a VIE due to certain risks shared with customers. We are the primary beneficiary because we have the power to direct the activities that most significantly impact Cardinal’s economic performance. We expect to fund future expansion activity with capital contributions from us and the other equity partner on a proportional basis.

Jackalope

We own a 50 percentinterest in Jackalope Gas Gathering Services, L.L.C. (Jackalope), a subsidiary that provides gathering and processing services for the Powder River basin and is a VIE due to certain risks shared with customers. We are the primary beneficiary because we have the power to direct the activities that most significantly impact Jackalope’s economic performance. We expect to fund future expansion activity with capital contributions from us and the other equity partner on a proportional basis.

14

Notes (Continued)

The following table presents amounts included in our Consolidated Balance Sheet that are for the use or obligation of our consolidated VIEs:

	March 31, 2017			December 31, 2016			Classification
	(Millions)
Assets (liabilities):
Cash and cash equivalents	$	101		$	82		Cash and cash equivalents
Accounts receivable	73			91			Trade accounts and other receivables
Prepaid assets	2			3			Other current assets and deferred charges
Property, plant, and equipment - net	2,990			3,024			Property, plant, and equipment - net
Intangible assets – net	1,419			1,431			Intangible assets – net of accumulated amortization
Accounts payable	(31		)	(44		)	Accounts payable – trade
Accrued liabilities	(3		)	(3		)	Other accrued liabilities
Current deferred revenue	(63		)	(63		)	Other accrued liabilities
Noncurrent asset retirement obligations	(101		)	(99		)	Asset retirement obligations
Noncurrent deferred revenue associated with customer advance payments	(320		)	(324		)	Regulatory liabilities, deferred income, and other

Note 3 – Allocation of Net Income (Loss) and Distributions

The allocation of net income (loss) among our general partner, limited partners, and noncontrolling interests within Equity is as follows:

	Three Months Ended   March 31,
	2017		2016
	(Millions)
Net income (loss) allocated to common limited partners’ equity (1)	$	623	$	43
Net income (loss) allocated to Class B limited partners’ equity	11		1
Net income (loss) allocated to general partner’s equity (1) (2)	—		6
Net income (loss) allocated to noncontrolling interests	26		29
Net income (loss)	$	660	$	79

(1) Net income (loss) allocated to equity accounts above considers distributions paid to partners during the current reporting period, while Net income (loss) allocated within the Consolidated Statement of Comprehensive Income (Loss) considers distributions declared for the current reporting period, but paid in the subsequent period. The 2016 differences between Net income (loss) allocated to equity accounts and Net income (loss) allocated within the Consolidated Statement of Comprehensive Income (Loss) are primarily due to the timing of the waiver of IDRs associated with the Termination Agreement. (See Note 1 – General, Description of Business, and Basis of Presentation.)

(2) As part of the first quarter 2017 Financial Repositioning (see Note 1 – General, Description of Business, and Basis of Presentation), our general partner interest in us was converted to a non-economic interest and therefore no longer receives an allocation of net income.

Common Units

The Board of Directors of our general partner declared a cash distribution of $0.60 per common unit on April 24, 2017, to be paid on May 12, 2017, to unitholders of record at the close of business on May 5, 2017.

15

Notes (Continued)

Class B Units

The Class B units are not entitled to cash distributions. Instead, prior to conversion into common units, the Class B units receive quarterly distributions of additional paid-in-kind Class B units. Effective February 10, 2015, each Class B unit became convertible at the election of either us or the holders of such Class B unit into a common unit on a one-for-one basis. The Board of Directors of our general partner has authorized the issuance of 251,859 Class B units associated with the first-quarter distribution, to be issued on May 12, 2017.

Note 4 – Investing Activities

Acquisition of Additional Interests in Appalachia Midstream Investments

During the first quarter of 2017, we exchanged all of our 50 percent interest in DBJV for an increased interest in two natural gas gathering systems that are part of the Appalachia Midstream Investments and $155 million in cash. This transaction was recorded based on our estimate of the fair value of the interests received as we have more insight to this value as we operate the underlying assets. Following this exchange, we have an approximate average 66 percent interest in the Appalachia Midstream Investments. We continue to account for this investment under the equity-method due to the significant participatory rights of our partners such that we do not exercise control. We also sold all of our interest in Ranch Westex JV LLC for $45 million. These transactions resulted in a total gain of $269 million reflected in Other investing income (loss) – netin theConsolidated Statement of Comprehensive Income (Loss).

The fair value of the increased interests in the Appalachia Midstream Investments received as consideration was estimated to be $1.1 billion using an income approach based on expected cash flows and an appropriate discount rate (a Level 3 measurement within the fair value hierarchy). The determination of estimated future cash flows involved significant assumptions regarding gathering volumes, rates, and related capital spending. A 9.5 percent discount rate was utilized and reflected our estimate of the cost of capital as impacted by market conditions and risks associated with the underlying business.

Impairments

The three months ended March 31, 2016, includes other-than-temporary impairment charges of $59 million and $50 million related to certain equity-method investments in DBJV and Laurel Mountain, respectively (see Note 8 – Fair Value Measurements and Guarantees).

Note 5 – Other Income and Expenses

The following table presents certain gains or losses reflected in Other (income) expense – netwithin Costs and expenses in our Consolidated Statement of Comprehensive Income (Loss):

	Three Months Ended   March 31,
	2017			2016
	(Millions)
West
Gains on contract settlements and terminations	$	(13	)	$	—
NGL & Petchem Services
Net foreign currency exchange (gains) losses (1)	—			11

(1) Primarily relates to gains and losses incurred on foreign currency transactions and the remeasurement of U.S. dollar denominated current assets and liabilities within our former Canadian operations.

16

Notes (Continued)

Additional Items

Certain additional items included in the Consolidated Statement of Comprehensive Income (Loss) are as follows:

• Service revenues were reduced by $15 million for the three months ended March 31, 2016, related to potential refunds associated with a ruling received in certain rate case litigation within the Atlantic-Gulf segment.

• Selling, general, and administrative expensesand Operating and maintenance expenses include $9 million in severance and other related costs for the three months ended March 31, 2017. The three months ended March 31, 2016 includes $25 million in severance and other related costs associated with an approximate 10 percent reduction in workforce in the first quarter of 2016. The amounts by segment are as follows:

	Three Months Ended   March 31,
	2017		2016
	(Millions)
Northeast G&P	$	—	$	3
Atlantic-Gulf	—		8
West	—		10
NGL & Petchem Services	—		4
Other	9		—

• Other income (expense) – net below Operating income (loss) includes $18 million and $17 million for the three months ended March 31, 2017 and 2016, respectively, for allowance for equity funds used during construction within the Atlantic-Gulf segment.

• Other income (expense) – net below Operating income (loss) includes a net gain of $30 million associated with the February 2017, early retirement of $750 million of 6.125 percent senior unsecured notes that were due in 2022. (See Note 6 – Debt and Banking Arrangements.) The net gain within the Other segment reflects $53 million of unamortized premium, partially offset by $23 million in premiums paid.

Note 6 – Debt and Banking Arrangements

Long-Term Debt

Issuances and retirements

On April 3, 2017, Northwest Pipeline issued $250 million of 4.0 percent senior unsecured notes due 2027 to investors in a private debt placement. Northwest Pipeline used the net proceeds to retire $185 million of 5.95 percent senior unsecured notes that matured on April 15, 2017, which are classified as long-term in the accompanying Consolidated Balance Sheet due to Northwest Pipeline’s intent and ability to refinance, and for general corporate purposes. As part of the new issuance, Northwest Pipeline entered into a registration rights agreement with the initial purchasers of the unsecured notes. Northwest Pipeline is obligated to file and consummate a registration statement for an offer to exchange the notes for a new issue of substantially identical notes registered under the Securities Act of 1933, as amended, within 365 days from closing and to use commercially reasonable efforts to complete the exchange offer. Northwest Pipeline is required to provide a shelf registration statement to cover resales of the notes under certain circumstances. If Northwest Pipeline fails to fulfill these obligations, additional interest will accrue on the affected securities. The rate of additional interest will be 0.25 percent per annum on the principal amount of the affected securities for the first 90-day period immediately following the occurrence of a registration default, increasing by an additional 0.25 percent per annum with respect to each subsequent 90-day period thereafter, up to a maximum amount for all such registration defaults of 0.5 percent annually. Following the cure of any registration defaults, the accrual of additional interest will cease.

17

Notes (Continued)

On February 23, 2017, utilizing proceeds received from the Financial Repositioning (see Note 1 – General, Description of Business, and Basis of Presentation), we early retired $750 million of 6.125 percent senior unsecured notes that were due in 2022.

We retired $600 million of 7.25 percent senior unsecured notes that matured on February 1, 2017.

Commercial Paper Program

As of March 31, 2017, no Commercial paper was outstanding under our $3 billion commercial paper program.

Credit Facilities

	March 31, 2017
	Stated Capacity		Outstanding
	(Millions)
Long-term credit facility (1)	$	3,500	$	—
Letters of credit under certain bilateral bank agreements			1

(1) In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program.

Note 7 – Partners’ Capital

Financial Repositioning

See Note 1 – General, Description of Business, and Basis of Presentation for information regarding units that were issued during the first quarter of 2017 related to the Financial Repositioning.

Distribution Reinvestment Program

The February 2017 distribution resulted in 395,395 common units issued to the public at a discounted average price of $39.76 per unit associated with the reinvested distributions of $16 million.

18

Notes (Continued)

Note 8 – Fair Value Measurements and Guarantees

The following table presents, by level within the fair value hierarchy, certain of our financial assets and liabilities. The carrying values of cash and cash equivalents, accounts receivable, commercial paper, and accounts payable approximate fair value because of the short-term nature of these instruments. Therefore, these assets and liabilities are not presented in the following table.

							Fair Value Measurements Using
	Carrying  Amount			Fair Value			Quoted Prices In Active  Markets for  Identical Assets (Level 1)		Significant  Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
	(Millions)
Assets (liabilities) at March 31, 2017:
Measured on a recurring basis:
ARO Trust investments	$	112		$	112		$	112	$	—		$	—
Energy derivatives assets designated as hedging instruments	5			5			5		—			—
Energy derivatives assets not designated as hedging instruments	2			2			1		—			1
Energy derivatives liabilities not designated as hedging instruments	(4		)	(4		)	—		—			(4		)
Additional disclosures:
Other receivables	5			5			5		—			—
Long-term debt	(17,065		)	(17,944		)	—		(17,944		)	—
Assets (liabilities) at December 31, 2016:
Measured on a recurring basis:
ARO Trust investments	$	96		$	96		$	96	$	—		$	—
Energy derivatives assets designated as hedging instruments	2			2			—		2			—
Energy derivatives assets not designated as hedging instruments	1			1			—		—			1
Energy derivatives liabilities not designated as hedging instruments	(6		)	(6		)	—		—			(6		)
Additional disclosures:
Other receivables	15			15			15		—			—
Long-term debt, including current portion	(18,470		)	(18,907		)	—		(18,907		)	—

Fair Value Methods

We use the following methods and assumptions in estimating the fair value of our financial instruments:

Assets and liabilities measured at fair value on a recurring basis

ARO Trust investments: Transco deposits a portion of its collected rates, pursuant to its rate case settlement, into an external trust (ARO Trust) that is specifically designated to fund future asset retirement obligations (ARO). The ARO Trust invests in a portfolio of actively traded mutual funds that are measured at fair value on a recurring basis based on quoted prices in an active market, is classified as available-for-sale, and is reported in Regulatory assets, deferred charges, and other in the Consolidated Balance Sheet. Both realized and unrealized gains and losses are ultimately recorded as regulatory assets or liabilities.

Energy derivatives: Energy derivatives include commodity based exchange-traded contracts and over-the-counter contracts, which consist of physical forwards, futures, and swaps that are measured at fair value on a recurring basis. The fair value amounts are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements. Further, the amounts do not include cash held on deposit in margin

19

Notes (Continued)

accounts that we have received or remitted to collateralize certain derivative positions. Energy derivatives assets are reported in Other current assets and deferred charges and Regulatory assets, deferred charges, and other in the Consolidated Balance Sheet. Energy derivatives liabilities are reported in Other accrued liabilities and Regulatory liabilities, deferred income, and other in the Consolidated Balance Sheet.

Reclassifications of fair value between Level 1, Level 2, and Level 3 of the fair value hierarchy, if applicable, are made at the end of each quarter. No transfers between Level 1 and Level 2 occurred during the three months ended March 31, 2017 or 2016.

Additional fair value disclosures

Other receivables: Other receivables consist of margin deposits, which are reported in Other current assets and deferred charges in the Consolidated Balance Sheet. The disclosed fair value of our margin deposits is considered to approximate the carrying value generally due to the short-term nature of these items.

Long-term debt: The disclosed fair value of our long-term debt is determined by a market approach using broker quoted indicative period-end bond prices. The quoted prices are based on observable transactions in less active markets for our debt or similar instruments.

Nonrecurring fair value measurements

The following table presents impairments of investments associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy.

						Impairments
						Three Months Ended March 31,
	Classification	Segment	Date of Measurement	Fair Value		2017		2016
				(Millions)
Equity-method investments (1)	Investments	West and Northeast G&P	March 31, 2016	$	1,294	$	—	$	109
Other equity-method investment	Investments	West	March 31, 2016	—		—		3
Impairment of equity-method investments						$	—	$	112

_________________

(1) Relates to West’s equity-method investment in DBJV and Northeast G&P’s equity-method investment in Laurel Mountain. Our carrying values in these equity-method investments had been written down to fair value at December 31, 2015. Our first-quarter 2016 analysis reflected higher discount rates for both of these investments, along with lower natural gas prices for Laurel Mountain. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 13.0 percent to 13.3 percent and reflected increases in our estimated cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses.

Guarantees

We are required by our revolving credit agreements to indemnify lenders for certain taxes required to be withheld from payments due to the lenders and for certain tax payments made by the lenders. The maximum potential amount of future payments under these indemnifications is based on the related borrowings and such future payments cannot currently be determined. These indemnifications generally continue indefinitely unless limited by the underlying tax regulations and have no carrying value. We have never been called upon to perform under these indemnifications and have no current expectation of a future claim.

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Notes (Continued)

Note 9 – Contingent Liabilities

Environmental Matters

We are a participant in certain environmental activities in various stages including assessment studies, cleanup operations, and remedial processes at certain sites, some of which we currently do not own. We are monitoring these sites in a coordinated effort with other potentially responsible parties, the U.S. Environmental Protection Agency (EPA), and other governmental authorities. We are jointly and severally liable along with unrelated third parties in some of these activities and solely responsible in others. Certain of our subsidiaries have been identified as potentially responsible parties at various Superfund and state waste disposal sites. In addition, these subsidiaries have incurred, or are alleged to have incurred, various other hazardous materials removal or remediation obligations under environmental laws. As of March 31, 2017, we have accrued liabilities totaling $17 million for these matters, as discussed below. Our accrual reflects the most likely costs of cleanup, which are generally based on completed assessment studies, preliminary results of studies, or our experience with other similar cleanup operations. Certain assessment studies are still in process for which the ultimate outcome may yield significantly different estimates of most likely costs. Any incremental amount in excess of amounts currently accrued cannot be reasonably estimated at this time due to uncertainty about the actual number of contaminated sites ultimately identified, the actual amount and extent of contamination discovered, and the final cleanup standards mandated by the EPA and other governmental authorities.

The EPA and various state regulatory agencies routinely promulgate and propose new rules, and issue updated guidance to existing rules. More recent rules and rulemakings include, but are not limited to, rules for reciprocating internal combustion engine maximum achievable control technology, new air quality standards for one hour nitrogen dioxide emissions, and volatile organic compound and methane new source performance standards impacting design and operation of storage vessels, pressure valves, and compressors. On October 1, 2015, the EPA issued its new rule regarding National Ambient Air Quality Standards for ground-level ozone, setting a new standard of 70 parts per billion. We are monitoring the rule’s implementation and evaluating potential impacts to our operations. For these and other new regulations, we are unable to estimate the costs of asset additions or modifications necessary to comply due to uncertainty created by the various legal challenges to these regulations and the need for further specific regulatory guidance.

Our interstate gas pipelines are involved in remediation activities related to certain facilities and locations for polychlorinated biphenyls, mercury, and other hazardous substances. These activities have involved the EPA and various state environmental authorities, resulting in our identification as a potentially responsible party at various Superfund waste sites. At March 31, 2017, we have accrued liabilities of $9 million for these costs. We expect that these costs will be recoverable through rates.

We also accrue environmental remediation costs for natural gas underground storage facilities, primarily related to soil and groundwater contamination. At March 31, 2017, we have accrued liabilities totaling $8 million for these costs.

Geismar Incident

On June 13, 2013, an explosion and fire occurred at our Geismar olefins plant and rendered the facility temporarily inoperable (Geismar Incident). As a result, there were two fatalities and numerous individuals (including employees and contractors) reported injuries. We are addressing the following contingent liabilities in connection with the Geismar Incident.

On October 21, 2013, the EPA issued an Inspection Report pursuant to the Clean Air Act’s Risk Management Program following its inspection of the facility on June 24 through June 28, 2013. The report notes the EPA’s preliminary determinations about the facility’s documentation regarding process safety, process hazard analysis, as well as operating procedures, employee training, and other matters. On June 16, 2014, we received a request for information related to the Geismar Incident from the EPA under Section 114 of the Clean Air Act to which we responded on August 13, 2014. The EPA could issue penalties pertaining to final determinations.

21

Notes (Continued)

Multiple lawsuits, including class actions for alleged offsite impacts, property damage, customer claims, and personal injury, have been filed against us. The first two trials, for nine plaintiffs claiming personal injury, were held in Louisiana state court in Iberville Parish, Louisiana in September and November 2016. The juries returned adverse verdicts against Williams, our subsidiary Williams Olefins, LLC, and other defendants. To date, we have settled those cases as well as settled or agreed in principle to settle numerous other personal injury claims, and such aggregate amount greater than our $2 million retention (deductible) value has been or will be recovered from our insurers. We believe these settlements to date substantially resolve any material exposure to such claims arising from the Geismar Incident. We believe that any additional losses arising from our alleged liability will be immaterial to our expected future annual results of operations, liquidity, and financial position and will be substantially covered by our general liability insurance policy, which has an aggregate limit of $610 million applicable to this event.

Royalty Matters

Certain of our customers, including one major customer, have been named in various lawsuits alleging underpayment of royalties and claiming, among other things, violations of anti-trust laws and the Racketeer Influenced and Corrupt Organizations Act. We have also been named as a defendant in certain of these cases in Pennsylvania based on allegations that we improperly participated with that major customer in causing the alleged royalty underpayments. We believe that the claims asserted are subject to indemnity obligations owed to us by that major customer. Due to the preliminary status of the cases, we are unable to estimate a range of potential loss at this time.

Unitholder Litigation

On March 7, 2016, a purported unitholder of us filed a putative class action on behalf of certain purchasers of our units in U.S. District Court in Oklahoma. The action names as defendants, us, Williams, Williams Partners GP LLC, Alan S. Armstrong, and Donald R. Chappel and alleges violations of certain federal securities laws for failure to disclose Energy Transfer Equity, L.P.’s intention to pursue a purchase of Williams conditioned on Williams not closing the WPZ Public Unit Exchange when announcing the WPZ Public Unit Exchange. The complaint seeks, among other things, damages and an award of costs and attorneys’ fees. The plaintiff filed an amended complaint on August 31, 2016. On October 17, 2016, we requested the court dismiss the action, and on March 8, 2017, the court dismissed the complaint with prejudice. On April 7, 2017, the plaintiff filed a notice of appeal. We cannot reasonably estimate a range of potential loss at this time.

Other

In addition to the foregoing, various other proceedings are pending against us which are incidental to our operations.

Summary

We have disclosed all significant matters for which we are unable to reasonably estimate a range of possible loss. We estimate that for all other matters for which we are able to reasonably estimate a range of loss, our aggregate reasonably possible losses beyond amounts accrued are immaterial to our expected future annual results of operations, liquidity, and financial position. These calculations have been made without consideration of any potential recovery from third parties.

Note 10 – Segment Disclosures

Our reportable segments are Northeast G&P, Atlantic-Gulf, West, and NGL & Petchem Services. (See Note 1 – General, Description of Business, and Basis of Presentation.) Certain other corporate activities are included in Other.

Performance Measurement

We evaluate segment operating performance based upon Modified EBITDA (earnings before interest, taxes, depreciation, and amortization). This measure represents the basis of our internal financial reporting and is the primary performance measure used by our chief operating decision maker in measuring performance and allocating resources among our reportable segments. Intersegment revenues primarily represent the sale of NGLs from our natural gas processing plants to our marketing business.

22

Notes (Continued)

We define Modified EBITDA as follows:

• Net income (loss) before:

◦ Provision (benefit) for income taxes;

◦ Interest incurred, net of interest capitalized;

◦ Equity earnings (losses);

◦ Impairment of equity-method investments;

◦ Other investing income (loss) – net;

◦ Impairment of goodwill;

◦ Depreciation and amortization expenses;

◦ Accretion expense associated with asset retirement obligations for nonregulated operations.

• This measure is further adjusted to include our proportionate share (based on ownership interest) of Modified EBITDA from our equity-method investments calculated consistently with the definition described above.

23

Notes (Continued)

The following table reflects the reconciliation of Segment revenues to Totalrevenues as reported in the Consolidated Statement of Comprehensive Income (Loss).

	Northeast G&P		Atlantic- Gulf		West		NGL & Petchem Services		Eliminations			Total
	(Millions)
Three Months Ended March 31, 2017
Segment revenues:
Service revenues
External	$	208	$	527	$	518	$	3	$	—		$	1,256
Internal	9		9		—		—		(18		)	—
Total service revenues	217		536		518		3		(18		)	1,256
Product sales
External	60		69		405		193		—			727
Internal	8		65		51		6		(130		)	—
Total product sales	68		134		456		199		(130		)	727
Total revenues	$	285	$	670	$	974	$	202	$	(148	)	$	1,983
Three Months Ended March 31, 2016
Segment revenues:
Service revenues
External	$	216	$	471	$	531	$	8	$	—		$	1,226
Internal	3		7		—		—		(10		)	—
Total service revenues	219		478		531		8		(10		)	1,226
Product sales
External	18		36		211		163		—			428
Internal	5		33		31		5		(74		)	—
Total product sales	23		69		242		168		(74		)	428
Total revenues	$	242	$	547	$	773	$	176	$	(84	)	$	1,654

The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Comprehensive Income (Loss).

	Three Months Ended   March 31,
	2017			2016
	(Millions)
Modified EBITDA by segment:
Northeast G&P	226			220
Atlantic-Gulf	450			382
West	385			327
NGL & Petchem Services	51			26
Other	20			—
	1,132			955
Accretion expense associated with asset retirement obligations for nonregulated operations	(6		)	(7		)
Depreciation and amortization expenses	(433		)	(435		)
Equity earnings (losses)	107			97
Impairment of equity-method investments	—			(112		)
Other investing income (loss) – net	271			—
Proportional Modified EBITDA of equity-method investments	(194		)	(189		)
Interest expense	(214		)	(229		)
(Provision) benefit for income taxes	(3		)	(1		)
Net income (loss)	$	660		$	79

24

Notes (Continued)

The following table reflects Total assets by reportable segment.  

	Total Assets
	March 31,   2017			December 31,   2016
	(Millions)
Northeast G&P	14,531			13,436
Atlantic-Gulf	14,402			14,176
West	17,171			18,479
NGL & Petchem Services	1,196			1,112
Other	243			161
Eliminations (1)	(605		)	(1,099		)
Total	$	46,938		$	46,265

(1) Eliminations primarily relate to the intercompany accounts and notes receivable generated by our cash management program.

25

Item 2

Management’s Discussion and Analysis of

Financial Condition and Results of Operations

General

We are an energy infrastructure master limited partnership focused on connecting North America’s significant hydrocarbon resource plays to growing markets for natural gas and NGLs through our gas pipeline and midstream businesses. WPZ GP LLC, a Delaware limited liability company wholly owned by Williams, is our general partner.

Our interstate natural gas pipeline strategy is to create value by maximizing the utilization of our pipeline capacity by providing high quality, low cost transportation of natural gas to large and growing markets. Our gas pipeline businesses’ interstate transmission and storage activities are subject to regulation by the FERC and as such, our rates and charges for the transportation of natural gas in interstate commerce, and the extension, expansion or abandonment of jurisdictional facilities and accounting, among other things, are subject to regulation. The rates are established through the FERC’s ratemaking process. Changes in commodity prices and volumes transported have limited near-term impact on these revenues because the majority of cost of service is recovered through firm capacity reservation charges in transportation rates.

The ongoing strategy of our midstream operations is to safely and reliably operate large-scale midstream infrastructure where our assets can be fully utilized and drive low per-unit costs. We focus on consistently attracting new business by providing highly reliable service to our customers. These services include natural gas gathering, processing, treating, and compression, NGL fractionation and transportation, crude oil production handling and transportation, olefin production, marketing services for NGL, oil and natural gas, as well as storage facilities.

Effective January 1, 2017, we implemented organizational changes, consistent with the manner in which our chief operating decision maker evaluates performance and allocates resources. Operations previously reported within the Central segment are now generally managed and presented within the West segment. Certain businesses previously within our NGL & Petchem Services segment are now managed and presented within the West, Atlantic-Gulf, and Northeast G&P segments. Certain other corporate activities are included in Other. Prior period segment disclosures have been recast for these segment changes. As a result, beginning with the reporting of first-quarter 2017, our reportable segments are Northeast G&P, Atlantic-Gulf, West, and NGL & Petchem Services, which are comprised of the following businesses:

• Northeast G&P is comprised of our midstream gathering and processing businesses in the Marcellus Shale region primarily in Pennsylvania, New York, and West Virginia and the Utica Shale region of eastern Ohio, as well as a 66 percent interest in Cardinal (a consolidated entity), a 62 percent equity-method investment in UEOM, a 69 percent equity-method investment in Laurel Mountain, a 58 percent equity-method investment in Caiman II, and Appalachia Midstream Services, LLC, which owns equity-method investments with an approximate average 66 percent interest in multiple gas gathering systems in the Marcellus Shale (Appalachia Midstream Investments).

• Atlantic-Gulf is comprised of our interstate natural gas pipeline, Transco, and significant natural gas gathering and processing and crude oil production handling and transportation assets in the Gulf Coast region, including a 51 percent interest in Gulfstar One (a consolidated entity), which is a proprietary floating production system, and various petrochemical and feedstock pipelines in the Gulf Coast region, as well as a 50 percent equity-method investment in Gulfstream, a 60 percent equity-method investment in Discovery, and a 41 percent interest in Constitution (a consolidated entity), which is under development.

• West is comprised of our interstate natural gas pipeline, Northwest Pipeline, and our gathering, processing and treating operations in New Mexico, Colorado, and Wyoming, as well as the Barnett Shale region of north-central Texas, the Eagle Ford Shale region of south Texas, the Haynesville Shale region of northwest Louisiana, and the Mid-Continent region which includes the Anadarko, Arkoma, Delaware, and Permian basins. This segment also includes our NGL and natural gas marketing business, storage facilities, an undivided 50 percent

26

Management’s Discussion and Analysis (Continued)

interest in an NGL fractionator near Conway, Kansas and a 50 percent equity-method investment in OPPL, as well as our previously owned 50 percent equity-method investment in the Delaware basin gas gathering system (DBJV) in the Mid-Continent region (see Note 4 – Investing Activities of Notes to Consolidated Financial Statements).

• NGL & Petchem Services is comprised of our 88.5 percent undivided interest in an olefins production facility in Geismar, Louisiana, which as of March 31, 2017, the Geismar operations are considered held for sale (see Geismar olefins facility monetization below) along with a refinery grade propylene splitter in the Gulf region, as well as the previously owned Canadian assets which included an oil sands offgas processing plant near Fort McMurray, Alberta, and a NGL/olefin fractionation facility at Redwater, Alberta. In September 2016, these Canadian operations were sold.

Financial Repositioning

In January 2017, we announced agreements with Williams, wherein Williams permanently waived the general partner’s IDRs and converted its 2 percent general partner interest in us to a non-economic interest in exchange for 289 million newly issued common units. Pursuant to this agreement, Williams also purchased approximately 277 thousand common units for $10 million. Additionally, Williams purchased approximately 59 million common units at a price of $36.08586 per unit in a private placement transaction. According to the terms of this agreement, following our quarterly distribution in February 2017, Williams paid additional consideration of approximately $50 million to us for these units. Following these transactions and as of March 31, 2017, Williams owns a 74 percent limited partner interest in us.

Unless indicated otherwise, the following discussion and analysis of results of operations and financial condition and liquidity should be read in conjunction with the consolidated financial statements and notes thereto of this Form 10‑Q and our Annual Report on Form 10-K dated February 22, 2017.

Distributions

On April 24, 2017,our general partner’s Board of Directors approved a quarterly distribution to unitholders of $0.60 per common unit on May 12, 2017, on our outstanding common units to unitholders of record at the close of business on May 5, 2017.

Overview of Three Months EndedMarch 31, 2017

Net income (loss) attributable to controlling interests for the three months ended March 31, 2017, increased $584 million compared to the three months ended March 31, 2016, reflecting a $141 million improvement in operating income, a gain of $269 million associated with the disposition of certain equity-method investments and the absence of $112 million of impairments of equity-method investments incurred in 2016.

West

Acquisition of additional interests in Appalachia Midstream Investments

During the first quarter of 2017, we exchanged all of our 50 percent interest in DBJV for an increased interest in two natural gas gathering systems that are part of the Appalachia Midstream Investments and $155 million in cash. Following this exchange, we have an approximate average 66 percent interest in the Appalachia Midstream Investments. We also sold all of our interest in Ranch Westex JV LLC for $45 million. These transactions resulted in a total gain of $269 million reflected in Other investing income (loss) – net in the Consolidated Statement of Comprehensive Income (Loss) within the West segment. (See Note 4 - Investing Activities of Notes to Consolidated Financial Statements.)

NGL & Petchem Services

Geismar olefins facility monetization

On April 17, 2017, we announced that we agreed to sell our Geismar Interest for $2.1 billion in cash, subject to customary closing conditions and regulatory approvals. Upon closing of the sale, we will enter into a long-term supply

27

Management’s Discussion and Analysis (Continued)

and transportation agreement with the purchaser to provide feedstock to the plant via our Bayou Ethane pipeline system. We expect that the sale will close during the summer of 2017 (see Note 1 – General, Description of Business, and Basis of Presentation of Notes to Consolidated Financial Statements).

We plan to use the cash proceeds from this sale to pay off our $850 million term loan and to fund a portion of the capital and investment expenditures that are a part of our growth portfolio.

Commodity Prices

NGL per-unit margins were approximately 120 percent higher in the first quarter of 2017 compared to the same period of 2016. The main driver for the three month comparative period increase was a 108 percent increase in per-unit non-ethane prices. The per-unit margin increase also reflects the absence of our former Canadian operations which had lower per-unit NGL margins in the prior year compared to our domestic operations. These favorable impacts were partially offset by an approximate 65 percent increase in per-unit natural gas feedstock prices.

NGL margins are defined as NGL revenues less any applicable Btu replacement cost, plant fuel, and third-party transportation and fractionation. Per-unit NGL margins are calculated based on sales of our own equity volumes at the processing plants. Our equity volumes include NGLs where we own the rights to the value from NGLs recovered at our plants under both “keep-whole” processing agreements, where we have the obligation to replace the lost heating value with natural gas, and “percent-of-liquids” agreements whereby we receive a portion of the extracted liquids with no obligation to replace the lost heating value.

The following graph illustrates NGL production and sales volumes, as well as the margin differential between ethane and non-ethane products and the relative mix of those products.

The potential impact of commodity prices on our business for the remainder of 2017 is further discussed in the following Company Outlook.

28

Management’s Discussion and Analysis (Continued)

Company Outlook

Our strategy is to provide large-scale energy infrastructure designed to maximize the opportunities created by the vast supply of natural gas and natural gas products that exists in the United States. We accomplish this by connecting the growing demand for cleaner fuels and feedstocks with our major positions in the premier natural gas and natural gas products supply basins. We continue to maintain a strong commitment to safety, environmental stewardship, operational excellence, and customer satisfaction. We believe that accomplishing these goals will position us to deliver safe and reliable service to our customers and an attractive return to our unitholders.

Our business plan for 2017 includes the previously discussed financial repositioning transactions. We expect to distribute $0.60 per unit, or $2.40 annually, beginning with the next distribution for the quarter ending March 31, 2017. Our business plan also includes the previously discussed asset monetizations, including the $2.1 billion sale of our ownership interest in the Geismar olefins facility expected to close this summer, as well as other select assets that are not core to our strategy. These transactions are expected to improve our cost of capital, remove our need to access the public equity markets for the next several years, enhance our growth, and provide for debt reduction.

Our growth capital and investment expenditures in 2017 are expected to total $2.1 billion to $2.8 billion. Approximately $1.4 billion to $1.9 billion of our growth capital funding needs include Transco expansions and other interstate pipeline growth projects, most of which are fully contracted with firm transportation agreements. The remaining growth capital spending in 2017 primarily reflects investment in gathering and processing systems in the Northeast G&P segment limited primarily to known new producer volumes, including volumes that support Transco expansion projects including our Atlantic Sunrise project. In addition to growth capital and investment expenditures, we also remain committed to projects that maintain our assets for safe and reliable operations, as well as projects that meet legal, regulatory, and/or contractual commitments.

As a result of our significant continued capital and investment expenditures on Transco expansions and fee-based gathering and processing projects, as well as the previously discussed sale of our Canadian operations and the pending monetization of the Geismar olefins facility, fee-based businesses are becoming an even more significant component of our portfolio and serve to reduce the influence of commodity price fluctuations on our operating results and cash flows. We expect to benefit as continued growth in demand for low-cost natural gas is driven by increases in LNG exports, industrial demand and power generation. Current forward market prices indicate a slightly more favorable energy commodity price environment in 2017 as compared to 2016, including higher natural gas and NGL prices. However, some of our customers may continue to curtail or delay drilling plans until there is a more sustained recovery in prices, which may negatively impact our gathering volumes. Although there has been some improvement, the credit profiles of certain of our producer customers remain challenged. Unfavorable changes in energy commodity prices or the credit profile of our producer customers may also result in noncash impairments of our assets.

In 2017, our operating results are expected to include increases from our regulated fee-based businesses recently placed in service or expected to be placed in service in 2017, primarily along the Transco system. For our non-regulated businesses, we anticipate increases in fee-based revenue due to expanded capacity in the the Eastern Gulf area and a slight increase in fee-based revenue in the Northeast G&P segment. Partially offsetting these increases are expected declines in fee-based revenue in the West segment. We expect overall gathering and processing volumes to remain steady in 2017 and increase thereafter to meet the growing demand for natural gas and natural gas products. We also anticipate lower general and administrative expenses due to cost reduction initiatives and asset monetizations.

Potential risks and obstacles that could impact the execution of our plan include:

• Opposition to infrastructure projects, including the risk of delay or denial in permits needed for our projects;

•Unexpected significant increases in capital expenditures or delays in capital project execution;

•Counterparty credit and performance risk, including that of Chesapeake Energy Corporation and its affiliates;

•Inability to execute or delay in completing planned asset monetizations;

29

Management’s Discussion and Analysis (Continued)

• Lower than anticipated demand for natural gas and natural gas products which could result in lower than expected volumes, energy commodity prices and margins;

•General economic, financial markets, or further industry downturn, including increased interest rates;

•Physical damages to facilities, including damage to offshore facilities by named windstorms;

•Reduced availability of insurance coverage.

We seek to maintain a strong financial position and liquidity, as well as manage a diversified portfolio of energy infrastructure assets which continue to serve key growth markets and supply basins in the United States.

Expansion Projects

Our ongoing major expansion projects include the following:

Northeast G&P

Gathering System Expansion

We will continue to expand the gathering systems in the Marcellus and Utica Shale regions that are needed to meet our customers’ production plans. The expansion of the gathering infrastructure includes additional compression and gathering pipeline to the existing system.

Atlantic-Gulf

Atlantic Sunrise

In February 2017, we received approval from the FERC to expand Transco’s existing natural gas transmission system along with greenfield facilities to provide incremental firm transportation capacity from the northeastern Marcellus producing area to markets along Transco’s mainline as far south as Station 85 in west central Alabama. On April 19, 2017, we filed a request with the FERC for approval of an approximately six mile route variance for the greenfield pipeline, which the FERC is treating as an application to amend our certificate for the project. We expect to place a portion of the mainline project facilities into service during the second half of 2017 and are targeting a full in-service during mid-2018, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 1,700 Mdth/d.

Constitution Pipeline

In December 2014, we received approval from the FERC to construct and operate the jointly owned Constitution pipeline, which will have an expected capacity of 650 Mdth/d. However, in April 2016, the New York State Department of Environmental Conservation (NYSDEC) denied a necessary water quality certification for the New York portion of the pipeline. We remain steadfastly committed to the project, and in May 2016, Constitution appealed the NYSDEC’s denial of the certification and filed an action in federal court seeking a declaration that the State of New York’s authority to exercise permitting jurisdiction over certain other environmental matters is preempted by federal law. The oral argument before the Second Circuit Court of Appeals regarding the NYSDEC’s denial of Constitution’s application for water quality certification under Section 401 of the Clean Water Act was held on November 16, 2016. We anticipate a decision from the Second Circuit Court of Appeals as early as the second quarter of 2017. (See Note 2 – Variable Interest Entities of Notes to Consolidated Financial Statements.) We currently own 41 percent of Constitution with three other parties holding 25 percent, 24 percent, and 10 percent, respectively. We will be the operator of Constitution. The 126-mile Constitution pipeline will connect our gathering system in Susquehanna County, Pennsylvania, to the Iroquois Gas Transmission and Tennessee Gas Pipeline systems in New York, as well as to a local distribution company serving New York and Pennsylvania. In light of the NYSDEC’s denial of the water quality certification and the actions taken to challenge the decision, the target in-service date has been revised to as early as the second half of 2018, which assumes that the legal challenge process is satisfactorily and promptly concluded.

30

Management’s Discussion and Analysis (Continued)

Dalton

In August 2016, we obtained approval from the FERCto expand Transco’s existing natural gas transmission system together with greenfield facilities to provide incremental firm transportation capacity from Station 210 in New Jersey to markets in northwest Georgia. On April 1, 2017, we began providing firm transportation service through the mainline portion of the project on an interim basis, until the in-service date of the project as a whole. We plan to place the full project into service in the third quarter of 2017 and it is expected to increase capacity by 448 Mdth/d.

Garden State

In April 2016, we received approval from the FERC to expand Transco’s existing natural gas transmission system to provide incremental firm transportation capacity from Station 210 in New Jersey to a new interconnection on our Trenton Woodbury Lateral in New Jersey. The project will be constructed in phases and is expected to increase capacity by 180 Mdth/d. We plan to place the initial phase of the project into service during the third quarter of 2017 and the remaining portion in the second quarter of 2018.

Gulf Connector

In August 2016, we filed an application with the FERC to expand Transco’s existing natural gas transmission system to provide incremental firm transportation capacity from Station 65 in Louisiana to delivery points in Wharton and San Patricio Counties, Texas. The project will be constructed in two phases, with the initial phase of the project expected to be in service during the second half of 2018 and the remaining phase in 2019, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 475 Mdth/d.

Hillabee

In February 2016, the FERC issued a certificate order for the initial phases of Transco’s Hillabee Expansion Project. The project involves an expansion of Transco’s existing natural gas transmission system from Station 85 in west central Alabama to a proposed new interconnection with the Sabal Trail project in Alabama. The project will be constructed in phases, and all of the project expansion capacity will be leased to Sabal Trail. We plan to place a portion of the initial phase of the project into service in the second quarter of 2017 and the remainder of the initial phase into service in the third quarter of 2017. The in-service date of the second phase of the project is planned for the second quarter of 2020 and together they are expected to increase capacity by 1,025 Mdth/d.

In March 2016, we entered into an agreement with the member-sponsors of Sabal Trail to resolve several matters. In accordance with the agreement, the member-sponsors will pay us an aggregate amount of $240 million in three equal installments as certain milestones of the project are met. The first $80 million payment was received in March 2016 and the second installment was received in September 2016. We expect to recognize income associated with these receipts over the term of the capacity lease agreement.

New York Bay Expansion

In July 2016, we received approval from the FERC to expand Transco’s existing natural gas transmission system to provide incremental firm transportation capacity from Pennsylvania to the Rockaway Delivery Lateral transfer point and the Narrows meter station in Richmond County, New York. We plan to place the project into service during the fourth quarter of 2017, and it is expected to increase capacity by 115 Mdth/d.

Norphlet Project

In March 2016, we announced that we have reached an agreement to provide deepwater gas gathering services to the Appomattox development in the Gulf of Mexico. The project will provide offshore gas gathering services to our existing Transco lateral, which will provide transmission services onshore to our Mobile Bay processing facility. We also plan to make modifications to our Main Pass 261 Platform to install an alternate delivery route from the platform, as well as modifications to our Mobile Bay processing facility. The project is scheduled to go into service during the second quarter of 2020.

31

Management’s Discussion and Analysis (Continued)

Northeast Supply Enhancement

In March 2017, we filed an application with the FERC to expand Transco’s existing natural gas transmission system to provide incremental firm transportation capacity from Station 195 in Pennsylvania to the Rockaway Delivery Lateral transfer point. We plan to place the project into service in late 2019 or during the first half of 2020, assuming timely receipt of all necessary regulatory approvals. The project is expected to increase capacity by 400 Mdth/d.

Virginia Southside II

In July 2016, we received approval from the FERC to expand Transco’s existing natural gas transmission system together with greenfield facilities to provide incremental firm transportation capacity from Station 210 in New Jersey and Station 165 in Virginia to a new lateral extending from our Brunswick Lateral in Virginia. We plan to place the project into service during the fourth quarter of 2017 and it is expected to increase capacity by 250 Mdth/d.

West

Eagle Ford

We plan to expand our gathering infrastructure in the Eagle Ford region in order to meet our customers’ production plans. The expansion of the gathering infrastructure includes the addition of well connections and gathering pipeline to the existing systems.

Critical Accounting Estimates

Constitution Pipeline Capitalized Project Costs

As of March 31, 2017, Property, plant, and equipment, at costin our Consolidated Balance Sheet includes approximately $381 million of capitalized project costs for Constitution, for which we are the construction manager and own a 41 percent consolidated interest. In December 2014, Constitution received approval from the FERC to construct and operate its proposed pipeline. However, in April 2016, the NYSDEC denied a necessary water quality certification for the New York portion of the pipeline. We remain steadfastly committed to the project, and in May 2016, Constitution appealed the NYSDEC's denial of the water quality certification.

As a result of the denial by the NYSDEC, we evaluated the capitalized project costs for impairment as of March 31, 2017, and determined that no impairment was necessary. Our evaluation considered probability-weighted scenarios of undiscounted future net cash flows, including a scenario assuming successful resolution with the NYSDEC and construction of the pipeline, as well as a scenario where the project does not proceed. We continue to monitor the capitalized project costs associated with Constitution for potential impairment.

32

Management’s Discussion and Analysis (Continued)

Results of Operations

Consolidated Overview

The following table and discussion is a summary of our consolidated results of operations for the three months ended March 31, 2017, compared to the three months ended March 31, 2016. The results of operations by segment are discussed in further detail following this consolidated overview discussion.

	Three Months Ended   March 31,
	2017			2016			$ Change*	% Change*
	(Millions)
Revenues:
Service revenues	$	1,256		$	1,226		+30	+2	%
Product sales	727			428			+299	+70	%
Total revenues	1,983			1,654
Costs and expenses:
Product costs	579			317			-262	-83	%
Operating and maintenance expenses	361			382			+21	+5	%
Depreciation and amortization expenses	433			435			+2	—	%
Selling, general, and administrative expenses	156			181			+25	+14	%
Other (income) expense – net	4			30			+26	+87	%
Total costs and expenses	1,533			1,345
Operating income (loss)	450			309
Equity earnings (losses)	107			97			+10	+10	%
Impairment of equity-method investments	—			(112		)	+112	+100	%
Other investing income (loss) – net	271			—			+271	NM
Interest expense	(214		)	(229		)	+15	+7	%
Other income (expense) – net	49			15			+34	NM
Income (loss) before income taxes	663			80
Provision (benefit) for income taxes	3			1			-2	-200	%
Net income (loss)	660			79
Less: Net income attributable to noncontrolling interests	26			29			+3	+10	%
Net income (loss) attributable to controlling interests	$	634		$	50

* + = Favorable change; - = Unfavorable change; NM = A percentage calculation is not meaningful due to a change in signs, a zero-value denominator, or a percentage change greater than 200.

Three months ended March 31, 2017 vs. three months ended March 31, 2016

Service revenuesincreased primarily due to higher volumes primarily in the eastern Gulf Coast region, including the impact of new volumes at Gulfstar One related to the Gunflint expansion being placed in service in the third quarter of 2016, higher production associated with the absence of producers' 2016 operational issues in the Tubular Bells field, and higher volumes at Devils Tower related to Kodiak field production. Additionally, an increase in Transco’s storage revenues reflects the absence of a reduction for potential refunds associated with a ruling received in certain rate case litigation in 2016. Service revenues also increased due to the recognition of deferred revenue in the Barnett Shale and Mid-Continent regions associated with the restructuring of contracts in the fourth quarter of 2016. These increases were partially offset by lower rates primarily in the Barnett Shale region associated with the previously discussed contract

33

Management’s Discussion and Analysis (Continued)

restructure as well as lower volumes primarily in the Barnett Shale region driven by natural declines. Other areas in the western region were also impacted by lower volumes related to natural declines and severe winter weather conditions.

Product sales increased due to higher marketing revenues primarily associated with significantly higher NGL prices and slightly higher NGL volumes. Revenues from the sale of our equity NGLs increased primarily due to higher NGL prices, partially offset by lower volumes. Olefins sales increased primarily due to higher propylene prices, partially offset by lower volumes. The decrease in equity NGL and olefin volumes reflect the sale of our former Canadian operations in September 2016.

The increase in Product costs is primarily due to higher marketing purchases primarily associated with an increase in per-unit costs across most products, especially NGLs, and higher volumes across most products. Product costs also reflect a slight increase in costs associated with the production of NGLs and olefins.

Operating and maintenance expenses decreased primarily due to lower labor-related costs resulting from our workforce reductions that occurred late in first-quarter 2016, and ongoing cost containment efforts, as well as the absence of costs associated with our former Canadian operations. These decreases are partially offset by an increase in costs associated with Transco’s expansion projects, including pipeline testing and general maintenance.

Selling, general, and administrative expenses decreased primarily due to lower labor-related costs resulting from our workforce reductions that occurred late in first-quarter 2016, and ongoing cost containment efforts, as well as the absence of costs associated with our former Canadian operations.

The favorable change in Other (income) expense – net within Operating income (loss) includes gains from certain contract settlements and terminations in 2017, the absence of an unfavorable change in foreign currency exchange associated with our former Canadian operations, and insurance proceeds received in 2017 associated with the Geismar Incident, offset by the accrual of additional expenses in 2017 related to the Geismar Incident.

Operating income (loss) changed favorably primarily due to lower costs and expenses associated with ongoing cost containment efforts, including the workforce reductions in first-quarter 2016, the sale of our Canadian operations, improved product margins primarily due to a significant increase in per-unit NGL margins, and higher service revenues.

The decrease in Impairment of equity-method investments reflects the absence of first-quarter 2016 impairment charges associated with our DBJV and Laurel Mountain equity-method investments. (See Note 8 – Fair Value Measurements and Guaranteesof Notes to Consolidated Financial Statements.)

Other investing income (loss) - net reflects the gain on disposition of our investments in DBJV and Ranch Westex JV LLC in 2017. (See Note 4 – Investing Activities of Notes to Consolidated Financial Statements.)

Interest expense decreased primarily due to lower Interest incurred primarily attributable to debt retirements and the absence of borrowings on our credit facility in the first quarter of 2017. (See Note 6 – Debt and Banking Arrangements of Notes to Consolidated Financial Statements.)

Other income (expense) – net below Operating income (loss) changed favorably primarily due to a $30 million net gain on early debt retirement in 2017, which is included in our Other segment. (See Note 5 – Other Income and Expenses of Notes to Consolidated Financial Statements).

Period-Over-Period Operating Results – Segments

We evaluate segment operating performance based upon Modified EBITDA. Note 10 – Segment Disclosures of Notes to Consolidated Financial Statements includes a reconciliation of this non-GAAP measure to Net income (loss). Management uses Modified EBITDA because it is an accepted financial indicator used by investors to compare company performance. In addition, management believes that this measure provides investors an enhanced perspective of the operating performance of our assets. Modified EBITDA should not be considered in isolation or as a substitute for a measure of performance prepared in accordance with GAAP.

34

Management’s Discussion and Analysis (Continued)

Northeast G&P

	Three Months Ended   March 31,
	2017			2016
	(Millions)
Service revenues	$	217		$	219
Product sales	68			23
Segment revenues	285			242
Product costs	(69		)	(21		)
Other segment costs and expenses	(87		)	(99		)
Proportional Modified EBITDA of equity-method investments	97			98
Northeast G&P Modified EBITDA	$	226		$	220

Three months ended March 31, 2017 vs. three months ended March 31, 2016

Modified EBITDA increased slightly primarily due lower Other segment costs and expenses driven by cost containment efforts including a workforce reduction in the first quarter of 2016 and the absence of certain impairments in the first quarter of 2016.

Service revenuesdecreased primarily due to a $22 million decrease in the Utica gathering system associated with 27 percent lower gathered volumes driven by natural declines, partially offset by a $12 million increase in fee revenues in our Ohio Valley Midstream operations driven by new and increased supplies in the first quarter of 2017 along with producer shut-ins in the first quarter of 2016. The decrease in Service revenues was also partially offset by a $9 million increase in the Susquehanna Supply Hub driven by 9 percent higher gathered volumes.

Product sales increased primarily due to significantly higher non-ethane prices within our marketing activities. The changes in marketing revenues are offset by similar changes in marketing purchases, reflected above as Product costs.

Other segment costs and expenses decreased primarily due to lower labor-related costs resulting from our first quarter 2016 workforce reductions and the absence of certain impairments in the first quarter of 2016.

Proportional Modified EBITDA of equity-method investments is slightly unfavorable primarily due to a $10 million decrease in UEOM driven by lower processing volumes from the Utica gathering system, partially offset by increases from other equity-method investments.

35

Management’s Discussion and Analysis (Continued)

Atlantic-Gulf

	Three Months Ended   March 31,
	2017			2016
	(Millions)
Service revenues	$	536		$	478
Product sales	134			69
Segment revenues	670			547
Product costs	(118		)	(64		)
Other segment costs and expenses	(174		)	(167		)
Proportional Modified EBITDA of equity-method investments	72			66
Atlantic-Gulf Modified EBITDA	$	450		$	382
NGL margin	$	14		$	5

Three months ended March 31, 2017 vs. three months ended March 31, 2016

Modified EBITDA increased primarily due to higher service revenues and higher NGL margins driven by higher NGL prices, partially offset by higher per-unit natural gas prices.

Service revenues increased primarily due to:

• A $43 million increase in eastern Gulf Coast region fee revenues primarily related to the impact of new volumes at Gulfstar One related to the Gunflint expansion placed in service in the third quarter of 2016 and higher production from the absence of producers’ 2016 operational issues in the Tubular Bells field, along with higher volumes at Devils Tower related to the Kodiak field;

• A $15 million increase in Transco’s storage revenue related to the absence of potential refunds associated with a ruling received in certain rate case litigation in 2016;

• A $4 million increase in Transco’s natural gas transportation fee revenues primarily due to a $13 million increase associated with expansion projects placed in service in 2016, partially offset by lower volume-based transportation services revenues.

Product sales increased primarily due to:

• A $45 million increase in crude oil and NGL marketing revenues. Crude oil marketing sales increased by $31 million primarily due to 68 percent higher crude oil per barrel sales prices and 54 percent higher volumes, primarily associated with the marketing of higher volumes at Devils Tower. NGL marketing sales increased $14 million primarily due to a 77 percent increase in non-ethane sales prices. These changes in marketing revenues are offset by similar changes in marketing purchases;

• A $19 million increase in revenues from our equity NGLs primarily due to a $7 million increase related to a 70 percent increase in realized non-ethane prices and a $10 million increase as a result of sales from inventory, which temporarily increased during the latter part of 2016 while we experienced an increase in keep-whole volumes due to disrupted operations of a competitor.

Product costs increased primarily due to:

• A $44 million increase in marketing purchases (offset in Product sales);

36

Management’s Discussion and Analysis (Continued)

• A $10 million increase in natural gas purchases associated with the production of equity NGLs primarily due to a 61 percent increase in per-unit natural gas prices and increased sales from inventory.

Other segment costs and expenses primarily increased due to higher costs associated with Transco’s expansion projects, including pipeline testing and general maintenance. In addition, project development costs at Constitution are higher as we discontinued capitalization of these costs beginning in April 2016.

The increase in Proportional Modified EBITDA of equity-method investments includes a $7 million increase from Discovery primarily due to higher fee revenues attributable to new connections to the Keathley Canyon Connector in the first quarter of 2016 and higher NGL margins due to an increase in NGL prices, partially offset by lower volumes.

West

	Three Months Ended   March 31,
	2017			2016
	(Millions)
Service revenues	$	518		$	531
Product sales	456			242
Segment revenues	974			773
Product costs	(416		)	(222		)
Other segment costs and expenses	(198		)	(249		)
Proportional modified EBITDA of equity-method investments	25			25
West Modified EBITDA	$	385		$	327
NGL margin	$	37		$	20

Three months ended March 31, 2017 vs. three months ended March 31, 2016

Modified EBITDA increased primarily due to lower segment costs and expenseand higher per-unit NGL margins, partially offset by lower gathered volumes as a result of natural declines.

Service revenues decreased primarily due to lower volumes in the Barnett Shale, Niobrara, Eagle Ford Shale, and Four Corners region as a result of natural declines, along with lower gathering rates in the Barnett Shale area primarily due to the fourth quarter 2016 contract restructuring. More extreme weather in 2017 in the Rocky Mountains also impacted volumes. These decreases were partially offset by an increase related to the amortization of deferred revenue associated with the up-front cash payment received in conjunction with the fourth quarter 2016 Barnett Shale contract restructuring.

Product sales increased primarily due to:

• A $186 million increase in marketing revenues primarily due to a 71 percent increase in average non-ethane per-unit sales prices, a 47 percent increase in ethane prices and a 38 percent increase in natural gas prices (substantially offset by higher Product costs);

• A $27 million increase in revenues associated with our equity NGLs due to 73 percent higher non-ethane prices.

Product costs increased primarily due to:

• A $184 million increase in marketing purchases (substantially offset in Product sales);

• A $10 million increase in natural gas purchases associated with the production equity NGLs primarily due to a 56 percent increase in per-unit natural gas prices.

37

Management’s Discussion and Analysis (Continued)

Other segment costs and expenses decreased primarily due to our first quarter 2016 workforce reductions, gains from contract settlements and terminations, and ongoing cost containment efforts.

NGL & Petchem Services

	Three Months Ended   March 31,
	2017			2016
	(Millions)
Service revenues	$	3		$	8
Product sales	199			168
Segment revenues	202			176
Product costs	(124		)	(93		)
Other segment costs and expenses	(27		)	(57		)
NGL & Petchem Services Modified EBITDA	$	51		$	26
Olefins margin	$	71		$	70
NGL margin	—			5

Three months ended March 31, 2017 vs. three months ended March 31, 2016

Modified EBITDA increased primarily due to the absence of an $11 million first-quarter 2016 Modified EBITDA associated with our former Canadian operations that we sold in September 2016, as well as higher margins associated with our other olefin operations and higher marketing margins.

Service revenues declined due to the sale of our former Canadian operations.

Product salesincreasedprimarily due to:

• A $38 million increase in marketing revenues primarily due to higher olefin prices and volumes (partially offset by higher Product costs);

• An $11 million increase in olefin sales primarily due to a $25 million increase at our other olefin operations that includes a $22 million increase associated with higher propylene prices, partially offset by a $10 million decrease due to the sale of our former Canadian operations, and a $4 million decrease from our Geismar plant. The decrease from our Geismar plant includes a $36 million decrease in sales volumes, partially offset by a $32 million increase in sales prices, primarily due to 46 percent higher per-unit ethylene prices. The lower volumes were driven by plant downtime in first-quarter 2017 associated with an electrical outage and miscellaneous equipment issues;

• A $17 million decrease in NGL production revenues due to the sale of our former Canadian operations.

Product costs increased primarily due to:

• A $34 million increase in marketing product costs primarily due to higher olefin feedstock prices and volumes (more than offset by higher Product sales);

• A $10 million increase in olefin feedstock purchases primarily due to higher propylene feedstock costs at our other olefin operations, partially offset by $5 million in lower feedstock costs at Geismar due to lower volumes, and a $4 million reduction as a result of the sale of our former Canadian operations.

• A $12 million decrease in NGL product costs due to the sale of our former Canadian operations.

38

Management’s Discussion and Analysis (Continued)

The decrease in Other segment costs and expenses includes the absence of $27 million in operating and other expenses associated with our former Canadian operations, as well as the receipt of $9 million of insurance proceeds related to the Geismar Incident, offset by a $9 million accrual for additional expenses related to the Geismar Incident.

39

Management’s Discussion and Analysis (Continued)

Management’s Discussion and Analysis of Financial Condition and Liquidity

Outlook

Fee-based businesses are becoming an even more significant component of our portfolio and serve to reduce the influence of commodity price fluctuations on our cash flows. We expect to benefit as continued growth in demand for low-cost natural gas is driven by increases in LNG exports, industrial demand, and power generation.

We believe we have, or have access to, the financial resources and liquidity necessary to meet our requirements for working capital, capital and investment expenditures, unitholder distributions, and debt service payments while maintaining a sufficient level of liquidity. In particular, as previously discussed in Company Outlook, our expected growth capital and investment expenditures total approximately $2.1 billion to $2.8 billion in 2017. Approximately $1.4 billion to $1.9 billion of our growth capital funding needs include Transco expansions and other interstate pipeline growth projects, most of which are fully contracted with firm transportation agreements. The remaining growth capital spending in 2017 primarily reflects investment in gathering and processing systems in the Northeast region limited primarily to known new producer volumes, including volumes that support Transco expansion projects including our Atlantic Sunrise project. In addition to growth capital and investment expenditures, we also remain committed to projects that maintain our assets for safe and reliable operations, as well as projects that meet legal, regulatory, and/or contractual commitments. We retain the flexibility to adjust planned levels of capital and investment expenditures in response to changes in economic conditions or business opportunities.

We expect to use the cash proceeds from the $2.1 billion sale of our Geismar Interest to pay off our $850 million term loan and to fund a portion of the capital and investment expenditures that are a part of our growth portfolio.

Liquidity

Based on our forecasted levels of cash flow from operations and other sources of liquidity, we expect to have sufficient liquidity to manage our businesses in 2017. Our internal and external sources of consolidated liquidity to fund working capital requirements, capital and investment expenditures, distributions to unitholders, and debt service payments include:

• Cash and cash equivalents on hand;

• Cash generated from operations;

• Distributions from our equity-method investees based on our level of ownership;

• Cash proceeds from the January 2017 and February 2017 purchase of common units by Williams (see Note 1 – General, Description of Business, and Basis of Presentation of Notes to Consolidated Financial Statements);

• Use of our credit facility and/or commercial paper program;

• Proceeds from planned asset monetizations;

• Proceeds from the previously described exchange of our equity-method investment in certain non-operated assets in the Delaware basin for cash and additional equity-method investment in two Marcellus Shale gathering systems.

We anticipate our more significant uses of cash to be:

• Working capital requirements;

• Maintenance and expansion capital and investment expenditures;

40

Management’s Discussion and Analysis (Continued)

• Interest on our long-term debt;

• Repayment of current debt maturities and additional reductions in debt with funds received from the planned asset monetizations;

• Quarterly distributions to our unitholders.

Potential risks associated with our planned levels of liquidity discussed above include those previously discussed in Company Outlook.

As of March 31, 2017, we had a working capital surplus (current assets in excess of current liabilities) of $940 million. Our available liquidity is as follows:

Available Liquidity	March 31, 2017
	(Millions)
Cash and cash equivalents	$	625
Capacity available under our $3.5 billion credit facility, less amounts outstanding under our $3 billion commercial paper program (1)	3,500
	$	4,125

(1) In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program. As of March 31, 2017, no Commercial paper was outstanding under our commercial paper program. Through March 31, 2017, the highest amount outstanding under our commercial paper program and credit facility during 2017 was $178 million. At March 31, 2017, we were in compliance with the financial covenants associated with this credit facility. Borrowing capacity available under our $3.5 billion credit facility as of May 2, 2017, was $3.5 billion.

Registrations

In September 2016, we filed a registration statement for our distribution reinvestment program. (See Note 7 – Partners’ Capital of Notes to Consolidated Financial Statements.)

In February 2015, we filed a shelf registration statement, as a well-known seasoned issuer, and we also filed a shelf registration statement for the offer and sale from time to time of common units representing limited partner interests in us having an aggregate offering price of up to $1 billion. These sales are to be made over a period of time and from time to time in transactions at prices which are market prices prevailing at the time of sale, prices related to market price, or at negotiated prices. Such sales are to be made pursuant to an equity distribution agreement between us and certain banks who may act as sales agents or purchase for their own accounts as principals.

Distributions from Equity-Method Investees

The organizational documents of entities in which we have an equity-method investment generally require distribution of their available cash to their members on a quarterly basis. In each case, available cash is reduced, in part, by reserves appropriate for operating their respective businesses.

Credit Ratings

Our ability to borrow money is impacted by our credit ratings. Our current ratings are as follows:

Rating Agency	Outlook	Senior Unsecured Debt Rating	Corporate Credit Rating
S&P Global Ratings	Stable	BBB	BBB
Moody’s Investors Service	Stable	Baa3	N/A
Fitch Ratings	Rating Watch Positive	BBB-	N/A

41

Management’s Discussion and Analysis (Continued)

During March 2017, S&P Global Ratings upgraded the rating for WPZ, and in April 2017, Fitch Ratings changed the Outlook for WPZ to Rating Watch Positive. No assurance can be given that the credit rating agencies will continue to assign us investment-grade ratings even if we meet or exceed their current criteria for investment-grade ratios. A downgrade of our credit rating might increase our future cost of borrowing and would require us to provide additional collateral to third parties, negatively impacting our available liquidity. As of March 31, 2017, we estimate that a downgrade to a rating below investment-grade could require us to provide up to $403 million in additional collateral of either cash or letters of credit with third parties under existing contracts.

Cash Distributions to Unitholders

The Board of Directors of our general partner declared a cash distribution of $0.60 per common unit on April 24, 2017, to be paid on May 12, 2017, to unitholders of record at the close of business on May 5, 2017.

Sources (Uses) of Cash

The following table summarizes the sources (uses) of cash and cash equivalents for each of the periods presented (see Notes to Consolidated Financial Statements for the Notes referenced in the table):

	Cash Flow	Three Months Ended   March 31,
	Category	2017			2016
		(Millions)
Sources of cash and cash equivalents:
Operating activities - net	Operating	$	731		$	924
Proceeds from sales of common units (see Note 1)	Financing	2,178			—
Proceeds from dispositions of equity-method investments	Investing	200			—
Distributions from unconsolidated affiliates in excess of cumulative earnings	Investing	121			109
Contributions from noncontrolling interests	Financing	4			16
Proceeds from long-term debt	Financing	—			998
Proceeds from credit-facility borrowings	Financing	—			840
Uses of cash and cash equivalents:
Payments of long-term debt (see Note 6)	Financing	(1,350		)	—
Distributions paid (1)	Financing	(796		)	(516		)
Capital expenditures	Investing	(509		)	(463		)
Payments of commercial paper - net	Financing	(93		)	(365		)
Purchases of and contributions to equity-method investments	Investing	(52		)	(63		)
Dividends and distributions to noncontrolling interests	Financing	(43		)	(19		)
Payments on credit-facility borrowings	Financing	—			(1,525		)
Other sources / (uses) - net	Financing and Investing	89			93
Increase (decrease) in cash and cash equivalents		$	480		$	29

____________

(1) Includes $597 million and $304 million to Williams in 2017 and 2016, respectively.

Operating activities

The factors that determine operating activities are largely the same as those that affect Net income (loss), with the exception of noncash items such as Depreciation and amortization, Net (gain) loss on disposition of equity-method investments, and Impairment of equity-method investments. OurNet cash provided (used) by operating activitiesfor the three months ended March 31, 2017, decreased from the same period in 2016 primarily due to the absence in 2017

42

Management’s Discussion and Analysis (Continued)

of a Hillabee cash receipt (see Company Outlook) and certain minimum volume commitment receipts due to contract restructurings, partially offset by higher operating income in 2017.

Off-Balance Sheet Arrangements and Guarantees of Debt or Other Commitments

We have various other guarantees and commitments which are disclosed in Note 2 – Variable Interest Entities, Note 6 – Debt and Banking Arrangements, Note 8 – Fair Value Measurements and Guarantees, and Note 9 – Contingent Liabilities of Notes to Consolidated Financial Statements. We do not believe these guarantees and commitments or the possible fulfillment of them will prevent us from meeting our liquidity needs.

43

Item 3

Quantitative and Qualitative Disclosures About Market Risk

Interest Rate Risk

Our current interest rate risk exposure is related primarily to our debt portfolio and has not materially changed during the first three months of 2017.

44

Item 4

Controls and Procedures

Our management, including our general partner’s Chief Executive Officer and Chief Financial Officer, does not expect that our disclosure controls and procedures (as defined in Rules 13a - 15(e) and 15d - 15(e) of the Securities Exchange Act) (Disclosure Controls) or our internal control over financial reporting (Internal Controls) will prevent all errors and all fraud. A control system, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. Further, the design of a control system must reflect the fact that there are resource constraints, and the benefits of controls must be considered relative to their costs. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, within Williams Partners L.P. have been detected. These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple error or mistake. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people, or by management override of the control. The design of any system of controls also is based in part upon certain assumptions about the likelihood of future events, and there can be no assurance that any design will succeed in achieving its stated goals under all potential future conditions. Because of the inherent limitations in a cost-effective control system, misstatements due to error or fraud may occur and not be detected. We monitor our Disclosure Controls and Internal Controls and make modifications as necessary; our intent in this regard is that the Disclosure Controls and Internal Controls will be modified as systems change and conditions warrant.

Evaluation of Disclosure Controls and Procedures

An evaluation of the effectiveness of the design and operation of our Disclosure Controls was performed as of the end of the period covered by this report. This evaluation was performed under the supervision and with the participation of our management, including our general partner’s Chief Executive Officer and Chief Financial Officer. Based upon that evaluation, our general partner’s Chief Executive Officer and Chief Financial Officer concluded that these Disclosure Controls are effective at a reasonable assurance level.

Changes in Internal Control Over Financial Reporting

There have been no changes during the first quarter of 2017 that materially affected, or are reasonably likely to materially affect, our Internal Control over Financial Reporting.

PART II. OTHER INFORMATION

Item 1. Legal Proceedings

Environmental

Certain reportable legal proceedings involving governmental authorities under federal, state, and local laws regulating the discharge of materials into the environment are described below. While it is not possible for us to predict the final outcome of the proceedings which are still pending, we do not anticipate a material effect on our consolidated financial position if we receive an unfavorable outcome in any one or more of such proceedings.

On February 21, 2017, we received notice from the Environmental Enforcement Section of the United States Department of Justice regarding certain alleged violations of the Clean Air Act at our Moundsville facility as set forth in a Notice of Noncompliance issued by the EPA on January 14, 2016. The notice includes an offer to avoid further legal action on the alleged violations by paying $2 million. We are currently evaluating the communication and our response.

Other

The additional information called for by this item is provided in Note 9 – Contingent Liabilities of Notes to Consolidated Financial Statements included under Part I, Item 1. Financial Statements of this report, which information is incorporated by reference into this item.

45

Item 6. Exhibits

Exhibit No.		Description
2.1§	—	Agreement and Plan of Merger dated as of May 12, 2015, by and among The Williams Companies, Inc., SCMS LLC, Williams Partners L.P., and WPZ GP LLC (filed on May 13, 2015 as Exhibit 2.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
2.2§	—	Interest Swap and Purchase Agreement by and among Western Gas Partners, LP, WGR Operating, LP, Delaware Basin JV Gathering LLC, Williams Partners L.P., Williams Midstream Gas Services LLC, and Appalachia Midstream Services, L.L.C., dated February 9, 2017 (filed on February 10, 2017 as exhibit 2.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.1	—	Certificate of Limited Partnership of Chesapeake Midstream Partners, L.P. (filed on February 16, 2010 as Exhibit 3.1 to Williams Partners L.P.’s registration statement on Form S-1 (File No. 333-164905) and incorporated herein by reference).
3.2	—	Amendment to Certificate of Limited Partnership of Chesapeake Midstream Partners, L.P. (filed on July 30, 2012 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8‑K (File No. 001-34831) and incorporated herein by reference).
3.3	—	Amendment to Certificate of Limited Partnership of Access Midstream Partners, L.P. (filed on February 3, 2015 as Exhibit 3.5 to Williams Partners L.P.’s current report on Form 8‑K (File No. 001-34831) and incorporated herein by reference).
3.4	—	Composite Certificate of Limited Partnership of Williams Partners L.P. (filed on February 25, 2015 as Exhibit 3.4 to Williams Partners L.P.’s annual report on Form 10-K (File No. 001-34831) and incorporated herein by reference).
3.5	—	First Amended and Restated Agreement of Limited Partnership of Chesapeake Midstream Partners, L.P., dated August 3, 2010 (filed on August 5, 2010 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.6	—	Amendment No. 1 to the First Amended and Restated Agreement of Limited Partnership of Chesapeake Midstream Partners, L.P. dated as of July 24, 2012 (filed on July 30, 2012 as Exhibit 3.3 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.7	—	Amendment No. 2 to the First Amended and Restated Agreement of Limited Partnership of Access Midstream Partners, L.P. dated as of December 20, 2012 (filed on December 26, 2012 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.8	—	Amendment No. 3 to the First Amended and Restated Agreement of Limited Partnership of Access Midstream Partners, L.P. dated as of January 29, 2015 (filed on February 3, 2015 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.9	—	Amendment No. 4 to the First Amended and Restated Agreement of Limited Partnership of Access Midstream Partners, L.P. dated as of January 29, 2015 (filed on February 3, 2015 as Exhibit 3.4 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.10	—	Amendment No. 5 to the First Amended and Restated Agreement of Limited Partnership of Williams Partners L.P., dated as of June 10, 2015 (filed on June 12, 2015 as Exhibit 3 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).

46

Exhibit No.		Description
3.11	—	Amendment No. 6 to the First Amended and Restated Agreement of Limited Partnership of Williams Partners L.P., dated September 28, 2015 (filed on September 28, 2015 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.12	—	Amendment No. 7 to the First Amended and Restated Agreement of Limited Partnership of Williams Partners L.P., dated October 12, 2016 (filed on October 13, 2016 as Exhibit 3 to Williams Partners L.P’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.13	—	Amendment No. 8 to the First Amended and Restated Agreement of Limited Partnership of Williams Partners L.P., dated January 9, 2017 (filed on January 10, 2017 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.14	—	Composite Agreement of Limited Partnership of Williams Partners L.P. (filed on February 22, 2017 as Exhibit 3.14 to Williams Partners L.P.’s annual report on Form 10-K (File No. 001-34831) and incorporated herein by reference).
3.15	—	Certificate of Formation of Chesapeake Midstream GP, L.L.C. (filed on February 16, 2010 as Exhibit 3.3 to Williams Partners L.P.’s registration statement on Form S-1 (File No. 333-164905) and incorporated herein by reference).
3.16	—	Certificate of Amendment to Certificate of Formation of Chesapeake Midstream GP, L.L.C. (filed on July 30, 2012 as Exhibit 3.5 to Williams Partners L.P.’s current report on Form 8‑K (File No. 001-34831) and incorporated herein by reference).
3.17	—	Certificate of Amendment of Certificate of Formation of Access Midstream Partners GP, L.L.C. (filed on February 3, 2015 as Exhibit 3.2 to Williams Partners L.P.’s current report on Form 8‑K (File No. 001-34831) and incorporated herein by reference).
3.18	—	Composite Certificate of Formation of WPZ GP LLC (filed on February 25, 2015 as Exhibit 3.14 to Williams Partners L.P.’s annual report on Form 10-K (File No. 001-34831) and incorporated herein by reference).
3.19	—	Eighth Amended and Restated Limited Liability Company Agreement of WPZ GP LLC (filed on August 2, 2016 as Exhibit 3.17 to Williams Partners L.P.’s quarterly report on Form 10-Q (File No. 001-34831) and incorporated herein by reference).
10.1	—	Termination Agreement and Release, dated as of September 28, 2015, by and among The Williams Companies, Inc., SCMS LLC, Williams Partners L.P. and WPZ GP LLC (filed on September 28, 2015 as Exhibit 10.1 to Williams Partners L.P.’s current report on Form 8‑K (File No. 001-34831) and incorporated herein by reference).
10.2	—	Common Unit Issuance Agreement, dated January 9, 2017 (filed on January 10, 2017 as Exhibit 10.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
10.3	—	Common Unit Purchase Agreement, dated January 9, 2017 (filed on January 10, 2017 as Exhibit 10.2 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
12*	—	Computation of Ratio of Earnings to Fixed Charges.
31.1*	—	Certification of Chief Executive Officer pursuant to Rules 13a-14(a) and 15d-14(a) promulgated under the Securities Exchange Act of 1934, as amended, and Item 601(b)(31) of Regulation S-K, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

47

Exhibit No.		Description
31.2*	—	Certification of Chief Financial Officer pursuant to Rules 13a-14(a) and 15d-14(a) promulgated under the Securities Exchange Act of 1934, as amended, and Item 601(b)(31) of Regulation S-K, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
32**	—	Certification of Chief Executive Officer and Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
101.INS*	—	XBRL Instance Document.
101.SCH*	—	XBRL Taxonomy Extension Schema.
101.CAL*	—	XBRL Taxonomy Extension Calculation Linkbase.
101.DEF*	—	XBRL Taxonomy Extension Definition Linkbase.
101.LAB*	—	XBRL Taxonomy Extension Label Linkbase.
101.PRE*	—	XBRL Taxonomy Extension Presentation Linkbase.

* Filed herewith.

** Furnished herewith.

§ Pursuant to Item 601(b)(2) of Regulation S-K., the registrant agrees to furnish supplementally a copy of any omitted exhibit or schedule to the SEC upon request.

48

SIGNATURE

Pursuant to the requirements 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.

WILLIAMS PARTNERS L.P.

(Registrant)

By: WPZ GP LLC, its general partner

/s/ Ted T. Timmermans

Ted T. Timmermans

Vice President, Controller and Chief Accounting Officer (Duly Authorized Officer and Principal Accounting Officer)

May 4, 2017

EXHIBIT INDEX

Exhibit No.		Description
2.1§	—	Agreement and Plan of Merger dated as of May 12, 2015, by and among The Williams Companies, Inc., SCMS LLC, Williams Partners L.P., and WPZ GP LLC (filed on May 13, 2015 as Exhibit 2.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
2.2§	—	Interest Swap and Purchase Agreement by and among Western Gas Partners, LP, WGR Operating, LP, Delaware Basin JV Gathering LLC, Williams Partners L.P., Williams Midstream Gas Services LLC, and Appalachia Midstream Services, L.L.C., dated February 9, 2017 (filed on February 10, 2017 as exhibit 2.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.1	—	Certificate of Limited Partnership of Chesapeake Midstream Partners, L.P. (filed on February 16, 2010 as Exhibit 3.1 to Williams Partners L.P.’s registration statement on Form S-1 (File No. 333-164905) and incorporated herein by reference).
3.2	—	Amendment to Certificate of Limited Partnership of Chesapeake Midstream Partners, L.P. (filed on July 30, 2012 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8‑K (File No. 001-34831) and incorporated herein by reference).
3.3	—	Amendment to Certificate of Limited Partnership of Access Midstream Partners, L.P. (filed on February 3, 2015 as Exhibit 3.5 to Williams Partners L.P.’s current report on Form 8‑K (File No. 001-34831) and incorporated herein by reference).
3.4	—	Composite Certificate of Limited Partnership of Williams Partners L.P. (filed on February 25, 2015 as Exhibit 3.4 to Williams Partners L.P.’s annual report on Form 10-K (File No. 001-34831) and incorporated herein by reference).
3.5	—	First Amended and Restated Agreement of Limited Partnership of Chesapeake Midstream Partners, L.P., dated August 3, 2010 (filed on August 5, 2010 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.6	—	Amendment No. 1 to the First Amended and Restated Agreement of Limited Partnership of Chesapeake Midstream Partners, L.P. dated as of July 24, 2012 (filed on July 30, 2012 as Exhibit 3.3 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.7	—	Amendment No. 2 to the First Amended and Restated Agreement of Limited Partnership of Access Midstream Partners, L.P. dated as of December 20, 2012 (filed on December 26, 2012 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.8	—	Amendment No. 3 to the First Amended and Restated Agreement of Limited Partnership of Access Midstream Partners, L.P. dated as of January 29, 2015 (filed on February 3, 2015 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.9	—	Amendment No. 4 to the First Amended and Restated Agreement of Limited Partnership of Access Midstream Partners, L.P. dated as of January 29, 2015 (filed on February 3, 2015 as Exhibit 3.4 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.10	—	Amendment No. 5 to the First Amended and Restated Agreement of Limited Partnership of Williams Partners L.P., dated as of June 10, 2015 (filed on June 12, 2015 as Exhibit 3 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).

Exhibit No.		Description
3.11	—	Amendment No. 6 to the First Amended and Restated Agreement of Limited Partnership of Williams Partners L.P., dated September 28, 2015 (filed on September 28, 2015 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.12	—	Amendment No. 7 to the First Amended and Restated Agreement of Limited Partnership of Williams Partners L.P., dated October 12, 2016 (filed on October 13, 2016 as Exhibit 3 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.13	—	Amendment No. 8 to the First Amended and Restated Agreement of Limited Partnership of Williams Partners L.P., dated January 9, 2017 (filed on January 10, 2017 as Exhibit 3.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
3.14	—	Composite Agreement of Limited Partnership of Williams Partners L.P. (filed on February 22, 2017 as Exhibit 3.14 to Williams Partners L.P.’s annual report on Form 10-K (File No. 001-34831) and incorporated herein by reference).
3.15	—	Certificate of Formation of Chesapeake Midstream GP, L.L.C. (filed on February 16, 2010 as Exhibit 3.3 to Williams Partners L.P.’s registration statement on Form S-1 (File No. 333-164905) and incorporated herein by reference).
3.16	—	Certificate of Amendment to Certificate of Formation of Chesapeake Midstream GP, L.L.C. (filed on July 30, 2012 as Exhibit 3.5 to Williams Partners L.P.’s current report on Form 8‑K (File No. 001-34831) and incorporated herein by reference).
3.17	—	Certificate of Amendment of Certificate of Formation of Access Midstream Partners GP, L.L.C. (filed on February 3, 2015 as Exhibit 3.2 to Williams Partners L.P.’s current report on Form 8‑K (File No. 001-34831) and incorporated herein by reference).
3.18	—	Composite Certificate of Formation of WPZ GP LLC (filed on February 25, 2015 as Exhibit 3.14 to Williams Partners L.P.’s annual report on Form 10-K (File No. 001-34831) and incorporated herein by reference).
3.19	—	Eighth Amended and Restated Limited Liability Company Agreement of WPZ GP LLC (filed on August 2, 2016 as Exhibit 3.17 to Williams Partners L.P.’s quarterly report on Form 10-Q (File No. 001-34831) and incorporated herein by reference).
10.1	—	Termination Agreement and Release, dated as of September 28, 2015, by and among The Williams Companies, Inc., SCMS LLC, Williams Partners L.P. and WPZ GP LLC (filed on September 28, 2015 as Exhibit 10.1 to Williams Partners L.P.’s current report on Form 8‑K (File No. 001-34831) and incorporated herein by reference).
10.2	—	Common Unit Issuance Agreement, dated January 9, 2017 (filed on January 10, 2017 as Exhibit 10.1 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
10.3	—	Common Unit Purchase Agreement, dated January 9, 2017 (filed on January 10, 2017 as Exhibit 10.2 to Williams Partners L.P.’s current report on Form 8-K (File No. 001-34831) and incorporated herein by reference).
12*	—	Computation of Ratio of Earnings to Fixed Charges.
31.1*	—	Certification of Chief Executive Officer pursuant to Rules 13a-14(a) and 15d-14(a) promulgated under the Securities Exchange Act of 1934, as amended, and Item 601(b)(31) of Regulation S-K, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

Exhibit No.		Description
31.2*	—	Certification of Chief Financial Officer pursuant to Rules 13a-14(a) and 15d-14(a) promulgated under the Securities Exchange Act of 1934, as amended, and Item 601(b)(31) of Regulation S-K, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
32**	—	Certification of Chief Executive Officer and Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
101.INS*	—	XBRL Instance Document.
101.SCH*	—	XBRL Taxonomy Extension Schema.
101.CAL*	—	XBRL Taxonomy Extension Calculation Linkbase.
101.DEF*	—	XBRL Taxonomy Extension Definition Linkbase.
101.LAB*	—	XBRL Taxonomy Extension Label Linkbase.
101.PRE*	—	XBRL Taxonomy Extension Presentation Linkbase.

* Filed herewith.

** Furnished herewith.

§ Pursuant to Item 601(b)(2) of Regulation S-K., the registrant agrees to furnish supplementally a copy of any omitted exhibit or schedule to the SEC upon request.

EX-12

Exhibit 12

Williams Partners L.P.

Computation of Ratio of Earnings to Fixed Charges

	Three Months Ended
	March 31, 2017
	(Millions)
Earnings:
Income (loss) before income taxes	$	663
Less: Equity earnings	(107		)
Income (loss) before income taxes and equity earnings	556
Add:
Fixed charges:
Interest incurred	221
Rental expense representative of interest factor	2
Total fixed charges	223
Distributed income of equity-method investees	190
Less:
Interest capitalized	(7		)
Total earnings as adjusted	$	962
Fixed charges	$	223
Ratio of earnings to fixed charges	4.31

EX-31.1

Exhibit 31.1

CERTIFICATIONS

I, Alan S. Armstrong, certify that:

1. I have reviewed this quarterly report on Form 10-Q of Williams Partners L.P.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, 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;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 4, 2017

/s/ Alan S. Armstrong

Alan S. Armstrong

Chief Executive Officer of WPZ GP LLC, general partner of Williams Partners L.P.

(Principal Executive Officer)

EX-31.2

Exhibit 31.2

CERTIFICATIONS

I, Donald R. Chappel, certify that:

1. I have reviewed this quarterly report on Form 10-Q of Williams Partners L.P.;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, 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;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 4, 2017

/s/ Donald R. Chappel

Donald R. Chappel

Chief Financial Officer of WPZ GP LLC,

general partner of Williams Partners L.P.

(Principal Financial Officer)

EX-32

Exhibit 32

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Williams Partners L.P. (the “Partnership”) on Form 10-Q for the period ending March 31, 2017, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), each of the undersigned hereby certifies, in his capacity as an officer of WPZ GP LLC (the “Company”), the general partner of the Partnership, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that to his knowledge:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Partnership.

/s/ Alan S. Armstrong

Alan S. Armstrong

President and Chief Executive Officer

May 4, 2017

/s/ Donald R. Chappel

Donald R. Chappel

Chief Financial Officer

May 4, 2017

A signed original of this written statement required by Section 906 has been provided to, and will be retained by, the Company and furnished to the Securities and Exchange Commission or its staff upon request.

The foregoing certification is being furnished to the Securities and Exchange Commission as an exhibit to the Report and shall not be considered filed as part of the Report.

XML

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 28, 2017
Entity Information [Line Items]
Entity Registrant Name	Williams Partners L.P.
Entity Central Index Key	0001483096
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Amendment Flag	false
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Partnership Units Outstanding		955,457,613
Common Class B [Member]
Entity Information [Line Items]
Entity Partnership Units Outstanding		17,065,816

XML

Consolidated Statement of Comprehensive Income (Loss) (Unaudited) - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues:
Service revenues	$ 1,256	$ 1,226
Product sales	727	428
Total revenues	1,983	1,654
Costs and expenses:
Product costs	579	317
Operating and maintenance expenses	361	382
Depreciation and amortization expenses	433	435
Selling, general, and administrative expenses	156	181
Other (income) expense - net	4	30
Total costs and expenses	1,533	1,345
Operating income (loss)	450	309
Equity earnings (losses)	107	97
Impairment of equity-method investments (Note 8)	0	(112)
Other investing income (loss) - net (Note 4)	271	0
Interest incurred	(221)	(240)
Interest capitalized	7	11
Other income (expense) - net	49	15
Income (loss) before income taxes	663	80
Provision (benefit) for income taxes	3	1
Net income (loss)	660	79
Less: Net income attributable to noncontrolling interests	26	29
Net Income (loss) attributable to controlling interests	634	50
Allocation of net income (loss) for calculation of earnings per common unit:
Net Income (loss) attributable to controlling interests	634	50
Allocation of net income (loss) to general partner	0	202
Allocation of net income (loss) to Class B units	11	(4)
Allocation of net income (loss) to common units	$ 623	$ (148)
Basic earnings per common unit:
Basic net income (loss) per common unit	$ 0.68	$ (0.25)
Basic weighted-average number of common units outstanding (thousands)	919,944	588,562
Diluted earnings per common unit:
Diluted net income (loss) per common unit	$ 0.68	$ (0.25)
Diluted weighted-average number of common units outstanding (thousands)	920,250	588,562
Cash distributions per common unit	$ 0.60	$ 0.85
Other Comprehensive Income (Loss):
Net unrealized gain (loss) from derivative instruments	$ 4	$ 0
Reclassifications into earnings of net derivative instruments (gain) loss	(1)	0
Foreign currency translation adjustments	0	72
Other comprehensive income (loss)	3	72
Comprehensive income (loss)	663	151
Less: Comprehensive income attributable to noncontrolling interests	26	29
Comprehensive income (loss) attributable to controlling interests	$ 637	$ 122

XML

Consolidated Balance Sheet (Unaudited) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 625	$ 145
Trade accounts and other receivables (net of allowance of $6 at March 31, 2017 and $6 at December 31, 2016)	861	926
Inventories	148	138
Assets held for sale (Note 1)	1,023	24
Other current assets and deferred charges	157	181
Total current assets	2,814	1,414
Investments	6,738	6,701
Property, plant, and equipment, at cost	37,677	38,247
Accumulated depreciation and amortization	(10,313)	(10,226)
Property, plant, and equipment – net	27,364	28,021
Intangible assets – net of accumulated amortization	9,569	9,662
Regulatory assets, deferred charges, and other	453	467
Total assets	46,938	46,265
Accounts payable:
Trade	656	589
Affiliate	76	109
Accrued interest	170	258
Asset retirement obligations	48	61
Liabilities held for sale (Note 1)	43	0
Other accrued liabilities	881	804
Commercial paper	0	93
Long-term debt due within one year	0	785
Total current liabilities	1,874	2,699
Long-term debt	17,065	17,685
Asset retirement obligations	830	798
Deferred income tax liabilities	19	20
Regulatory liabilities, deferred income, and other	1,951	1,860
Contingent liabilities (Note 9)
Partners’ equity:
Common units (955,455,083 and 607,064,550 units outstanding at March 31, 2017 and December 31, 2016, respectively)	22,680	18,300
Class B units (17,065,816 and 16,690,016 units outstanding at March 31, 2017 and December 31, 2016, respectively)	780	769
General partner	0	2,385
Accumulated other comprehensive income (loss)	2	(1)
Total partners’ equity	23,462	21,453
Noncontrolling interests in consolidated subsidiaries	1,737	1,750
Total equity	25,199	23,203
Total liabilities and equity	$ 46,938	$ 46,265

XML

Consolidated Balance Sheet (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowance for trade accounts and other receivables	$ 6	$ 6
Equity:
Common units outstanding	955,455,083	607,064,550
Class B units outstanding	17,065,816	16,690,016

XML

Consolidated Statement of Changes in Equity (Unaudited) - 3 months ended Mar. 31, 2017 - USD ($) $ in Millions	Total	General Partner [Member]	Common Units Limited Partners	Class B Units Limited Partners	Total Partners' Equity	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]
Beginning balance at Dec. 31, 2016	$ 23,203	$ 2,385	$ 18,300	$ 769	$ 21,453	$ (1)	$ 1,750
Net income (loss)	660	0	623	11	634	0	26
Other comprehensive income (loss)	3	0	0	0	3	3	0
Conversion to non-economic general partner interest (Note 1)	0	(2,385)	2,385	0	0	0	0
Distributions to The Williams Companies, Inc. - net	(11)	0	(11)	0	(11)	0	0
Sale of common units (Note 1)	2,194	0	2,194	0	2,194	0	0
Distributions to limited partners	(812)	0	(812)	0	(812)	0	0
Contributions from noncontrolling interests	4	0	0	0	0	0	4
Distributions to noncontrolling interests	(43)	0	0	0	0	0	(43)
Other	1	0	1	0	1	0	0
Net increase (decrease) in equity	1,996	(2,385)	4,380	11	2,009	3	(13)
Ending balance at Mar. 31, 2017	$ 25,199	$ 0	$ 22,680	$ 780	$ 23,462	$ 2	$ 1,737

XML

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
OPERATING ACTIVITIES:
Net income (loss)	$ 660	$ 79
Adjustments to reconcile to net cash provided (used) by operating activities:
Depreciation and amortization	433	435
Provision (benefit) for deferred income taxes	(1)	0
Net (gain) loss on disposition of equity-method investments	(269)	0
Impairment of equity-method investments	0	112
Impairment of and net (gain) loss on sale of assets and businesses	0	8
Amortization of stock-based awards	2	9
Cash provided (used) by changes in current assets and liabilities:
Accounts and notes receivable	22	298
Inventories	(30)	(15)
Other current assets and deferred charges	19	23
Accounts payable	38	(19)
Accrued liabilities	(28)	(70)
Affiliate accounts receivable and payable – net	(32)	(15)
Other, including changes in noncurrent assets and liabilities	(83)	79
Net cash provided (used) by operating activities	731	924
FINANCING ACTIVITIES:
Proceeds from (payments of) commercial paper – net	(93)	(365)
Proceeds from long-term debt	0	1,838
Payments of long-term debt	(1,350)	(1,526)
Proceeds from sales of common units	2,178	0
Contributions from general partner	0	3
Distributions paid	(796)	(516)
Distributions to noncontrolling interests	(43)	(19)
Contributions from noncontrolling interests	4	16
Distributions to The Williams Companies, Inc. – net	(11)	0
Payments for debt issuance costs	0	(8)
Other – net	(23)	1
Net cash provided (used) by financing activities	(134)	(576)
INVESTING ACTIVITIES:
Capital expenditures (1)	(509)	(463)
Net proceeds from dispositions	(2)	0
Proceeds from dispositions of equity-method investments	200	0
Purchases of and contributions to equity-method investments	(52)	(63)
Distributions from unconsolidated affiliates in excess of cumulative earnings	121	109
Other – net	125	98
Net cash provided (used) by investing activities	(117)	(319)
Increase (decrease) in cash and cash equivalents	480	29
Cash and cash equivalents at beginning of year	145	96
Cash and cash equivalents at end of period	625	125
(1) Increases to property, plant, and equipment	(569)	(498)
Changes in related accounts payable and accrued liabilities	60	35
Capital expenditures	$ (509)	$ (463)

XML

General, Description of Business, and Basis of Presentation

3 Months Ended

Mar. 31, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

General, Description of Business, and Basis of Presentation [Text Block]

Note 1 – General, Description of Business, and Basis of Presentation

General

Our accompanying interim consolidated financial statements do not include all the notes in our annual financial statements and, therefore, should be read in conjunction with the consolidated financial statements and notes thereto for the year ended December 31, 2016, in our Annual Report on Form 10-K. The accompanying unaudited financial statements include all normal recurring adjustments and others that, in the opinion of management, are necessary to present fairly our interim financial statements.

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Actual results could differ from those estimates.

Unless the context clearly indicates otherwise, references in this report to “we,” “our,” “us,” or like terms refer to Williams Partners L.P. and its subsidiaries. Unless the context clearly indicates otherwise, references to “we,” “our,” and “us” include the operations in which we own interests accounted for as equity-method investments that are not consolidated in our financial statements. When we refer to our equity investees by name, we are referring exclusively to their businesses and operations.

We are a Delaware limited partnership whose common units are listed and traded on the New York Stock Exchange. WPZ GP LLC, a Delaware limited liability company wholly owned by The Williams Companies, Inc. (Williams), serves as our general partner. Our operations are located in the United States.

Financial Repositioning

In January 2017, we announced agreements with Williams, wherein Williams permanently waived the general partner’s incentive distribution rights (IDRs) and converted its 2 percent general partner interest in us to a non-economic interest in exchange for 289 million newly issued common units. Pursuant to this agreement, Williams also purchased approximately 277 thousand common units for $10 million. Additionally, Williams purchased approximately 59 million common units at a price of $36.08586 per unit in a private placement transaction. According to the terms of this agreement, following our quarterly distribution in February 2017, Williams paid additional consideration of approximately $50 million to us for these units. Following these transactions and as of March 31, 2017, Williams owns a 74 percent limited partner interest in us.

Geismar Olefins Facility Assets Held For Sale

On April 17, 2017, we announced that we agreed to sell Williams Olefins, L.L.C., a wholly owned subsidiary which owns an interest in the Geismar, Louisiana, olefins plant (Geismar Interest) for $2.1 billion in cash, subject to customary closing conditions and regulatory approvals. Upon closing of the sale, we will enter into a long-term supply and transportation agreement with the purchaser to provide feedstock to the plant via our Bayou Ethane pipeline system. We expect that the sale will close during the summer of 2017.

The assets and liabilities of the Geismar olefins plant are presented as held for sale as of March 31, 2017. The following table presents the carrying amounts of the major classes of assets and liabilities included as part of the Geismar disposal group, which are presented within Assets held for sale and Liabilities held for sale in the Consolidated Balance Sheet. Also included in Assets held for sale in the Consolidated Balance Sheet are $24 million of assets held for sale within the West segment unrelated to the Geismar Interest and at December 31, 2016, were previously included in Other current assets and deferred charges.

	Carrying Amount
	March 31, 2017
	(Millions)
Assets:
Current assets	$	71
Property, plant, and equipment – net	901
Other noncurrent assets	27
	$	999
Liabilities:
Current liabilities	$	42
Noncurrent liabilities	1
	$	43

The following table presents the results of operations for the Geismar disposal group.

	Three Months Ended   March 31,
	2017		2016
	(Millions)
Income (loss) before income taxes of disposal group	$	23	$	18

Description of Business

Effective January 1, 2017, we implemented organizational changes, consistent with the manner in which our chief operating decision maker evaluates performance and allocates resources. Operations previously reported within the Central segment are now generally managed and presented within the West segment. Certain businesses previously within our NGL & Petchem Services segment are now managed and presented within the West, Atlantic-Gulf, and Northeast G&P segments. As a result, beginning with the reporting of first quarter 2017, our operations are organized into the following reportable segments: Northeast G&P, Atlantic-Gulf, West, and NGL & Petchem Services. Certain other corporate activities are included in Other. Prior period segment disclosures have been recast for these segment changes.

Northeast G&P is comprised of our midstream gathering and processing businesses in the Marcellus Shale region primarily in Pennsylvania, New York, and West Virginia and the Utica Shale region of eastern Ohio, as well as a 66 percent interest in Cardinal Gas Services, L.L.C. (Cardinal) (a consolidated entity), a 62 percent equity-method investment in Utica East Ohio Midstream, LLC (UEOM), a 69 percent equity-method investment in Laurel Mountain Midstream, LLC (Laurel Mountain), a 58 percent equity-method investment in Caiman Energy II, LLC (Caiman II), and Appalachia Midstream Services, LLC, which owns equity-method investments with an approximate average 66 percent interest in multiple gathering systems in the Marcellus Shale (Appalachia Midstream Investments).

Atlantic-Gulf is comprised of our interstate natural gas pipeline, Transcontinental Gas Pipe Line Company, LLC (Transco), and significant natural gas gathering and processing and crude oil production handling and transportation assets in the Gulf Coast region, including a 51 percent interest in Gulfstar One LLC (Gulfstar One) (a consolidated entity), which is a proprietary floating production system, and various petrochemical and feedstock pipelines in the Gulf Coast region, as well as a 50 percent equity-method investment in Gulfstream Natural Gas System, L.L.C. (Gulfstream), a 41 percent interest in Constitution Pipeline Company, LLC (Constitution) (a consolidated entity), which is under development, and a 60 percent equity-method investment in Discovery Producer Services LLC (Discovery).

West is comprised of our interstate natural gas pipeline, Northwest Pipeline LLC (Northwest Pipeline), and our gathering, processing, and treating operations in New Mexico, Colorado, and Wyoming, as well as the Barnett Shale region of north-central Texas, the Eagle Ford Shale region of south Texas, the Haynesville Shale region of northwest Louisiana, and the Mid-Continent region which includes the Anadarko, Arkoma, Delaware, and Permian basins. This segment also includes our NGL and natural gas marketing business, storage facilities, an undivided 50 percent interest in an NGL fractionator near Conway, Kansas, and a 50 percent equity-method investment in Overland Pass Pipeline, LLC (OPPL), as well as our previously owned 50 percent equity-method investment in the Delaware basin gas gathering system (DBJV) in the Mid-Continent region (see Note 4 – Investing Activities).

NGL & Petchem Services is comprised of our 88.5 percent undivided interest in an olefins production facility in Geismar, Louisiana (see Geismar Olefins Facility Assets Held For Sale), along with a refinery grade propylene splitter in the Gulf region, as well as the previously owned Canadian assets which included an oil sands offgas processing plant located near Fort McMurray, Alberta, and a natural gas liquid (NGL)/olefin fractionation facility at Redwater, Alberta. In September 2016, we completed the sale of our Canadian operations.

Basis of Presentation

Significant risks and uncertainties

We have announced plans to monetize assets that are not core to our strategy. As we pursue these asset monetizations, it is possible that we may incur impairments of certain equity-method investments, property, plant, and equipment, and intangible assets. Such impairments could potentially be caused by indications of fair value implied through the monetization process or, in the case of asset dispositions that are part of a broader asset group, the impact of the loss of future estimated cash flows.

Accounting standards issued but not yet adopted

In January 2017, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2017-04 “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment” (ASU 2017-04). ASU 2017-04 modifies the concept of goodwill impairment to represent the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. Under ASU 2017-04, entities will no longer be required to determine the implied fair value of goodwill by assigning the fair value of a reporting unit to its individual assets and liabilities as if that reporting unit had been acquired in a business combination. ASU 2017-04 is effective for goodwill impairment testing for interim and annual periods beginning after December 15, 2019, and requires a prospective transition. Early adoption is permitted for interim and annual goodwill impairment tests performed after January 1, 2017, and we plan to adopt this standard in 2017. Our West reportable segment has $47 million of goodwill included in Intangible assets - net of accumulated amortization in the Consolidated Balance Sheet.

In August 2016, the FASB issued ASU 2016-15 “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments” (ASU 2016-15). ASU 2016-15 provides specific guidance on eight cash flow classification issues, including debt prepayment or debt extinguishment costs and distributions received from equity method investees, to reduce diversity in practice. ASU 2016-15 is effective for interim and annual periods beginning after December 15, 2017. Early adoption is permitted. The new standard requires a retrospective transition. We are evaluating the impact of the new standard on our consolidated financial statements.

In June 2016, the FASB issued ASU 2016-13 “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (ASU 2016-13). ASU 2016-13 changes the impairment model for most financial assets and certain other instruments. For trade and other receivables, held-to-maturity debt securities, loans, and other instruments, entities will be required to use a new forward-looking “expected loss” model that generally will result in the earlier recognition of allowances for losses. The guidance also requires increased disclosures. ASU 2016-13 is effective for interim and annual periods beginning after December 15, 2019. Early adoption is permitted. The new standard requires varying transition methods for the different categories of amendments. We are evaluating the impact of the new standard on our consolidated financial statements. Although we do not expect this new standard to have a significant impact, it will impact our trade receivables as the related allowance for credit losses will be recognized earlier under the expected loss model.

In February 2016, the FASB issued ASU 2016-02 “Leases (Topic 842)” (ASU 2016-02). ASU 2016-02 establishes a comprehensive new lease accounting model. The new standard clarifies the definition of a lease, requires a dual approach to lease classification similar to current lease classifications, and causes lessees to recognize leases on the balance sheet as a lease liability with a corresponding right-of-use asset. ASU 2016-02 is effective for interim and annual periods beginning after December 15, 2018. Early adoption is permitted. The new standard requires a modified retrospective transition for capital or operating leases existing at or entered into after the beginning of the earliest comparative period presented in the financial statements. We are reviewing contracts to identify leases, particularly reviewing the applicability of this new standard to contracts involving easements/rights-of-way.

In May 2014, the FASB issued ASU 2014-09 establishing Accounting Standards Codification (ASC) Topic 606, “Revenue from Contracts with Customers” (ASC 606). ASC 606 establishes a comprehensive new revenue recognition model designed to depict the transfer of goods or services to a customer in an amount that reflects the consideration the entity expects to be entitled to receive in exchange for those goods or services and requires significantly enhanced revenue disclosures. In August 2015, the FASB issued ASU 2015-14 “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date” (ASU 2015-14). Per ASU 2015-14, the standard is effective for interim and annual reporting periods beginning after December 15, 2017. ASC 606 allows either full retrospective or modified retrospective transition and early adoption is permitted for annual periods beginning after December 15, 2016.

We continue to evaluate the impact the standard may have on our financial statements. For each revenue contract type, we are conducting a formal contract review process to evaluate the impact, if any, that the new revenue standard may have. We have substantially completed that process, but continue to evaluate our accounting for noncash consideration, which exists in contracts where we receive commodities as full or partial consideration and contracts with a significant financing component, which may exist in situations where the timing of the consideration we received varies significantly from the timing of when we provide the service. As such, we are unable to determine the potential impact upon the amount and timing of revenue recognition and related disclosures. Additionally, we have identified possible financial system and internal control changes necessary for adoption. We currently anticipate utilizing a modified retrospective transition upon the adoption of ASC 606 as of January 1, 2018.

Public Unit Exchange

On May 12, 2015, we entered into an agreement for a unit-for-stock transaction whereby Williams would have acquired all of our publicly held outstanding common units in exchange for shares of Williams’ common stock (WPZ Public Unit Exchange).

On September 28, 2015, we entered into a Termination Agreement and Release (Termination Agreement), terminating the WPZ Public Unit Exchange. Under the terms of the Termination Agreement, Williams was required to pay us a $428 million termination fee, which settled through a reduction of quarterly incentive distributions payable to Williams (such reduction not to exceed $209 million per quarter). Our November 2015, February 2016, and May 2016 distributions to Williams were reduced by $209 million, $209 million, and $10 million, respectively, related to this termination fee.

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Variable Interest Entities

3 Months Ended

Mar. 31, 2017

Variable Interest Entity Disclosures [Abstract]

Variable Interest Entities [Textblock]

Note 2 – Variable Interest Entities

As of March 31, 2017, we consolidate the following variable interest entities (VIEs):

Gulfstar One

We own a51 percent interest in Gulfstar One, a subsidiary that, due to certain risk-sharing provisions in its customer contracts, is a VIE. Gulfstar One includes a proprietary floating-production system, Gulfstar FPS, and associated pipelines which provide production handling and gathering services in the eastern deepwater Gulf of Mexico. We are the primary beneficiary because we have the power to direct the activities that most significantly impact Gulfstar One’s economic performance.

Constitution

We own a41 percent interest in Constitution, a subsidiary that, due to shipper fixed-payment commitments under its long-term firm transportation contracts, is a VIE. We are the primary beneficiary because we have the power to direct the activities that most significantly impact Constitution’s economic performance. We, as construction manager for Constitution, are responsible for constructing the proposed pipeline connecting our gathering system in Susquehanna County, Pennsylvania, to the Iroquois Gas Transmission and the Tennessee Gas Pipeline systems. The total remaining cost of the project is estimated to be approximately $691 million, which we expect will be funded with capital contributions from us and the other equity partners on a proportional basis.

In December 2014, Constitution received approval from the Federal Energy Regulatory Commission (FERC) to construct and operate its proposed pipeline. However, in April 2016, the New York State Department of Environmental Conservation (NYSDEC) denied a necessary water quality certification for the New York portion of the pipeline. We remain steadfastly committed to the project, and in May 2016, Constitution appealed the NYSDEC's denial of the water quality certification.The oral argument before the Second Circuit Court of Appeals regarding the NYSDEC’s denial of Constitution’s application for water quality certification under Section 401 of the Clean Water Act was held on November 16, 2016. We anticipate a decision from the Second Circuit Court of Appeals as early as the second quarter of 2017. In light of the NYSDEC's denial of the water quality certification and the actions taken to challenge the decision, the project in-service date is targeted as early as the second half of 2018, which assumes that the legal challenge process is satisfactorily and promptly concluded. An unfavorable resolution could result in the impairment of a significant portion of the capitalized project costs, which total $381 million on a consolidated basis at March 31, 2017, and are included within Property, plant, and equipment, at cost in the Consolidated Balance Sheet. Beginning in April 2016, we discontinued capitalization of development costs related to this project. It is also possible that we could incur certain supplier-related costs in the event of a prolonged delay or termination of the project.

Cardinal

We own a 66 percent interest in Cardinal, a subsidiary that provides gathering services for the Utica Shale region and is a VIE due to certain risks shared with customers. We are the primary beneficiary because we have the power to direct the activities that most significantly impact Cardinal’s economic performance. We expect to fund future expansion activity with capital contributions from us and the other equity partner on a proportional basis.

Jackalope

We own a 50 percentinterest in Jackalope Gas Gathering Services, L.L.C. (Jackalope), a subsidiary that provides gathering and processing services for the Powder River basin and is a VIE due to certain risks shared with customers. We are the primary beneficiary because we have the power to direct the activities that most significantly impact Jackalope’s economic performance. We expect to fund future expansion activity with capital contributions from us and the other equity partner on a proportional basis.

The following table presents amounts included in our Consolidated Balance Sheet that are for the use or obligation of our consolidated VIEs:

	March 31, 2017			December 31, 2016			Classification
	(Millions)
Assets (liabilities):
Cash and cash equivalents	$	101		$	82		Cash and cash equivalents
Accounts receivable	73			91			Trade accounts and other receivables
Prepaid assets	2			3			Other current assets and deferred charges
Property, plant, and equipment - net	2,990			3,024			Property, plant, and equipment - net
Intangible assets – net	1,419			1,431			Intangible assets – net of accumulated amortization
Accounts payable	(31		)	(44		)	Accounts payable – trade
Accrued liabilities	(3		)	(3		)	Other accrued liabilities
Current deferred revenue	(63		)	(63		)	Other accrued liabilities
Noncurrent asset retirement obligations	(101		)	(99		)	Asset retirement obligations
Noncurrent deferred revenue associated with customer advance payments	(320		)	(324		)	Regulatory liabilities, deferred income, and other

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Allocation of Net Income (Loss) and Distributions

3 Months Ended

Mar. 31, 2017

Equity [Abstract]

Allocation of Net Income (Loss) and Distributions

Note 3 – Allocation of Net Income (Loss) and Distributions

The allocation of net income (loss) among our general partner, limited partners, and noncontrolling interests within Equity is as follows:

	Three Months Ended   March 31,
	2017		2016
	(Millions)
Net income (loss) allocated to common limited partners’ equity (1)	$	623	$	43
Net income (loss) allocated to Class B limited partners’ equity	11		1
Net income (loss) allocated to general partner’s equity (1) (2)	—		6
Net income (loss) allocated to noncontrolling interests	26		29
Net income (loss)	$	660	$	79

(1) Net income (loss) allocated to equity accounts above considers distributions paid to partners during the current reporting period, while Net income (loss) allocated within the Consolidated Statement of Comprehensive Income (Loss) considers distributions declared for the current reporting period, but paid in the subsequent period. The 2016 differences between Net income (loss) allocated to equity accounts and Net income (loss) allocated within the Consolidated Statement of Comprehensive Income (Loss) are primarily due to the timing of the waiver of IDRs associated with the Termination Agreement. (See Note 1 – General, Description of Business, and Basis of Presentation.)

(2) As part of the first quarter 2017 Financial Repositioning (see Note 1 – General, Description of Business, and Basis of Presentation), our general partner interest in us was converted to a non-economic interest and therefore no longer receives an allocation of net income.

Common Units

The Board of Directors of our general partner declared a cash distribution of $0.60 per common unit on April 24, 2017, to be paid on May 12, 2017, to unitholders of record at the close of business on May 5, 2017.

Class B Units

The Class B units are not entitled to cash distributions. Instead, prior to conversion into common units, the Class B units receive quarterly distributions of additional paid-in-kind Class B units. Effective February 10, 2015, each Class B unit became convertible at the election of either us or the holders of such Class B unit into a common unit on a one-for-one basis. The Board of Directors of our general partner has authorized the issuance of 251,859 Class B units associated with the first-quarter distribution, to be issued on May 12, 2017.

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Investing Activities

3 Months Ended

Mar. 31, 2017

Equity Method Investments and Joint Ventures [Abstract]

Investing Activities [Text Block]

Note 4 – Investing Activities

Acquisition of Additional Interests in Appalachia Midstream Investments

During the first quarter of 2017, we exchanged all of our 50 percent interest in DBJV for an increased interest in two natural gas gathering systems that are part of the Appalachia Midstream Investments and $155 million in cash. This transaction was recorded based on our estimate of the fair value of the interests received as we have more insight to this value as we operate the underlying assets. Following this exchange, we have an approximate average 66 percent interest in the Appalachia Midstream Investments. We continue to account for this investment under the equity-method due to the significant participatory rights of our partners such that we do not exercise control. We also sold all of our interest in Ranch Westex JV LLC for $45 million. These transactions resulted in a total gain of $269 million reflected in Other investing income (loss) – netin theConsolidated Statement of Comprehensive Income (Loss).

The fair value of the increased interests in the Appalachia Midstream Investments received as consideration was estimated to be $1.1 billion using an income approach based on expected cash flows and an appropriate discount rate (a Level 3 measurement within the fair value hierarchy). The determination of estimated future cash flows involved significant assumptions regarding gathering volumes, rates, and related capital spending. A 9.5 percent discount rate was utilized and reflected our estimate of the cost of capital as impacted by market conditions and risks associated with the underlying business.

Impairments

The three months ended March 31, 2016, includes other-than-temporary impairment charges of $59 million and $50 million related to certain equity-method investments in DBJV and Laurel Mountain, respectively (see Note 8 – Fair Value Measurements and Guarantees).

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Other Income and Expenses

3 Months Ended

Mar. 31, 2017

Other Income and Expenses [Abstract]

Other income and expenses [Textblock]

Note 5 – Other Income and Expenses

The following table presents certain gains or losses reflected in Other (income) expense – netwithin Costs and expenses in our Consolidated Statement of Comprehensive Income (Loss):

	Three Months Ended   March 31,
	2017			2016
	(Millions)
West
Gains on contract settlements and terminations	$	(13	)	$	—
NGL & Petchem Services
Net foreign currency exchange (gains) losses (1)	—			11

(1) Primarily relates to gains and losses incurred on foreign currency transactions and the remeasurement of U.S. dollar denominated current assets and liabilities within our former Canadian operations.

Additional Items

Certain additional items included in the Consolidated Statement of Comprehensive Income (Loss) are as follows:

• Service revenues were reduced by $15 million for the three months ended March 31, 2016, related to potential refunds associated with a ruling received in certain rate case litigation within the Atlantic-Gulf segment.

• Selling, general, and administrative expensesand Operating and maintenance expenses include $9 million in severance and other related costs for the three months ended March 31, 2017. The three months ended March 31, 2016 includes $25 million in severance and other related costs associated with an approximate 10 percent reduction in workforce in the first quarter of 2016. The amounts by segment are as follows:

	Three Months Ended   March 31,
	2017		2016
	(Millions)
Northeast G&P	$	—	$	3
Atlantic-Gulf	—		8
West	—		10
NGL & Petchem Services	—		4
Other	9		—

• Other income (expense) – net below Operating income (loss) includes $18 million and $17 million for the three months ended March 31, 2017 and 2016, respectively, for allowance for equity funds used during construction within the Atlantic-Gulf segment.

• Other income (expense) – net below Operating income (loss) includes a net gain of $30 million associated with the February 2017, early retirement of $750 million of 6.125 percent senior unsecured notes that were due in 2022. (See Note 6 – Debt and Banking Arrangements.) The net gain within the Other segment reflects $53 million of unamortized premium, partially offset by $23 million in premiums paid.

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Debt and Banking Arrangements

3 Months Ended

Mar. 31, 2017

Debt Disclosure [Abstract]

Debt Disclosure [Text Block]

Note 6 – Debt and Banking Arrangements

Long-Term Debt

Issuances and retirements

On April 3, 2017, Northwest Pipeline issued $250 million of 4.0 percent senior unsecured notes due 2027 to investors in a private debt placement. Northwest Pipeline used the net proceeds to retire $185 million of 5.95 percent senior unsecured notes that matured on April 15, 2017, which are classified as long-term in the accompanying Consolidated Balance Sheet due to Northwest Pipeline’s intent and ability to refinance, and for general corporate purposes. As part of the new issuance, Northwest Pipeline entered into a registration rights agreement with the initial purchasers of the unsecured notes. Northwest Pipeline is obligated to file and consummate a registration statement for an offer to exchange the notes for a new issue of substantially identical notes registered under the Securities Act of 1933, as amended, within 365 days from closing and to use commercially reasonable efforts to complete the exchange offer. Northwest Pipeline is required to provide a shelf registration statement to cover resales of the notes under certain circumstances. If Northwest Pipeline fails to fulfill these obligations, additional interest will accrue on the affected securities. The rate of additional interest will be 0.25 percent per annum on the principal amount of the affected securities for the first 90-day period immediately following the occurrence of a registration default, increasing by an additional 0.25 percent per annum with respect to each subsequent 90-day period thereafter, up to a maximum amount for all such registration defaults of 0.5 percent annually. Following the cure of any registration defaults, the accrual of additional interest will cease.

On February 23, 2017, utilizing proceeds received from the Financial Repositioning (see Note 1 – General, Description of Business, and Basis of Presentation), we early retired $750 million of 6.125 percent senior unsecured notes that were due in 2022.

We retired $600 million of 7.25 percent senior unsecured notes that matured on February 1, 2017.

Commercial Paper Program

As of March 31, 2017, no Commercial paper was outstanding under our $3 billion commercial paper program.

Credit Facilities

	March 31, 2017
	Stated Capacity		Outstanding
	(Millions)
Long-term credit facility (1)	$	3,500	$	—
Letters of credit under certain bilateral bank agreements			1

(1) In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program.

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Partners' Capital

3 Months Ended

Mar. 31, 2017

Partners' Capital [Abstract]

Partners' Capital

Note 7 – Partners’ Capital

Financial Repositioning

See Note 1 – General, Description of Business, and Basis of Presentation for information regarding units that were issued during the first quarter of 2017 related to the Financial Repositioning.

Distribution Reinvestment Program

The February 2017 distribution resulted in 395,395 common units issued to the public at a discounted average price of $39.76 per unit associated with the reinvested distributions of $16 million.

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Fair Value Measurements and Guarantees

3 Months Ended

Mar. 31, 2017

Fair Value Disclosures [Abstract]

Fair Value Measurements and Guarantees [Text Block]

Note 8 – Fair Value Measurements and Guarantees

The following table presents, by level within the fair value hierarchy, certain of our financial assets and liabilities. The carrying values of cash and cash equivalents, accounts receivable, commercial paper, and accounts payable approximate fair value because of the short-term nature of these instruments. Therefore, these assets and liabilities are not presented in the following table.

							Fair Value Measurements Using
	Carrying  Amount			Fair Value			Quoted Prices In Active  Markets for  Identical Assets (Level 1)		Significant  Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
	(Millions)
Assets (liabilities) at March 31, 2017:
Measured on a recurring basis:
ARO Trust investments	$	112		$	112		$	112	$	—		$	—
Energy derivatives assets designated as hedging instruments	5			5			5		—			—
Energy derivatives assets not designated as hedging instruments	2			2			1		—			1
Energy derivatives liabilities not designated as hedging instruments	(4		)	(4		)	—		—			(4		)
Additional disclosures:
Other receivables	5			5			5		—			—
Long-term debt	(17,065		)	(17,944		)	—		(17,944		)	—
Assets (liabilities) at December 31, 2016:
Measured on a recurring basis:
ARO Trust investments	$	96		$	96		$	96	$	—		$	—
Energy derivatives assets designated as hedging instruments	2			2			—		2			—
Energy derivatives assets not designated as hedging instruments	1			1			—		—			1
Energy derivatives liabilities not designated as hedging instruments	(6		)	(6		)	—		—			(6		)
Additional disclosures:
Other receivables	15			15			15		—			—
Long-term debt, including current portion	(18,470		)	(18,907		)	—		(18,907		)	—

Fair Value Methods

We use the following methods and assumptions in estimating the fair value of our financial instruments:

Assets and liabilities measured at fair value on a recurring basis

ARO Trust investments: Transco deposits a portion of its collected rates, pursuant to its rate case settlement, into an external trust (ARO Trust) that is specifically designated to fund future asset retirement obligations (ARO). The ARO Trust invests in a portfolio of actively traded mutual funds that are measured at fair value on a recurring basis based on quoted prices in an active market, is classified as available-for-sale, and is reported in Regulatory assets, deferred charges, and other in the Consolidated Balance Sheet. Both realized and unrealized gains and losses are ultimately recorded as regulatory assets or liabilities.

Energy derivatives: Energy derivatives include commodity based exchange-traded contracts and over-the-counter contracts, which consist of physical forwards, futures, and swaps that are measured at fair value on a recurring basis. The fair value amounts are presented on a gross basis and do not reflect the netting of asset and liability positions permitted under the terms of our master netting arrangements. Further, the amounts do not include cash held on deposit in margin accounts that we have received or remitted to collateralize certain derivative positions. Energy derivatives assets are reported in Other current assets and deferred charges and Regulatory assets, deferred charges, and other in the Consolidated Balance Sheet. Energy derivatives liabilities are reported in Other accrued liabilities and Regulatory liabilities, deferred income, and other in the Consolidated Balance Sheet.

Reclassifications of fair value between Level 1, Level 2, and Level 3 of the fair value hierarchy, if applicable, are made at the end of each quarter. No transfers between Level 1 and Level 2 occurred during the three months ended March 31, 2017 or 2016.

Additional fair value disclosures

Other receivables: Other receivables consist of margin deposits, which are reported in Other current assets and deferred charges in the Consolidated Balance Sheet. The disclosed fair value of our margin deposits is considered to approximate the carrying value generally due to the short-term nature of these items.

Long-term debt: The disclosed fair value of our long-term debt is determined by a market approach using broker quoted indicative period-end bond prices. The quoted prices are based on observable transactions in less active markets for our debt or similar instruments.

Nonrecurring fair value measurements

The following table presents impairments of investments associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy.

						Impairments
						Three Months Ended March 31,
	Classification	Segment	Date of Measurement	Fair Value		2017		2016
				(Millions)
Equity-method investments (1)	Investments	West and Northeast G&P	March 31, 2016	$	1,294	$	—	$	109
Other equity-method investment	Investments	West	March 31, 2016	—		—		3
Impairment of equity-method investments						$	—	$	112

_________________

(1) Relates to West’s equity-method investment in DBJV and Northeast G&P’s equity-method investment in Laurel Mountain. Our carrying values in these equity-method investments had been written down to fair value at December 31, 2015. Our first-quarter 2016 analysis reflected higher discount rates for both of these investments, along with lower natural gas prices for Laurel Mountain. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 13.0 percent to 13.3 percent and reflected increases in our estimated cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses.

Guarantees

We are required by our revolving credit agreements to indemnify lenders for certain taxes required to be withheld from payments due to the lenders and for certain tax payments made by the lenders. The maximum potential amount of future payments under these indemnifications is based on the related borrowings and such future payments cannot currently be determined. These indemnifications generally continue indefinitely unless limited by the underlying tax regulations and have no carrying value. We have never been called upon to perform under these indemnifications and have no current expectation of a future claim.

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Contingent Liabilities

3 Months Ended

Mar. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Contingent Liabilities

Note 9 – Contingent Liabilities

Environmental Matters

We are a participant in certain environmental activities in various stages including assessment studies, cleanup operations, and remedial processes at certain sites, some of which we currently do not own. We are monitoring these sites in a coordinated effort with other potentially responsible parties, the U.S. Environmental Protection Agency (EPA), and other governmental authorities. We are jointly and severally liable along with unrelated third parties in some of these activities and solely responsible in others. Certain of our subsidiaries have been identified as potentially responsible parties at various Superfund and state waste disposal sites. In addition, these subsidiaries have incurred, or are alleged to have incurred, various other hazardous materials removal or remediation obligations under environmental laws. As of March 31, 2017, we have accrued liabilities totaling $17 million for these matters, as discussed below. Our accrual reflects the most likely costs of cleanup, which are generally based on completed assessment studies, preliminary results of studies, or our experience with other similar cleanup operations. Certain assessment studies are still in process for which the ultimate outcome may yield significantly different estimates of most likely costs. Any incremental amount in excess of amounts currently accrued cannot be reasonably estimated at this time due to uncertainty about the actual number of contaminated sites ultimately identified, the actual amount and extent of contamination discovered, and the final cleanup standards mandated by the EPA and other governmental authorities.

The EPA and various state regulatory agencies routinely promulgate and propose new rules, and issue updated guidance to existing rules. More recent rules and rulemakings include, but are not limited to, rules for reciprocating internal combustion engine maximum achievable control technology, new air quality standards for one hour nitrogen dioxide emissions, and volatile organic compound and methane new source performance standards impacting design and operation of storage vessels, pressure valves, and compressors. On October 1, 2015, the EPA issued its new rule regarding National Ambient Air Quality Standards for ground-level ozone, setting a new standard of 70 parts per billion. We are monitoring the rule’s implementation and evaluating potential impacts to our operations. For these and other new regulations, we are unable to estimate the costs of asset additions or modifications necessary to comply due to uncertainty created by the various legal challenges to these regulations and the need for further specific regulatory guidance.

Our interstate gas pipelines are involved in remediation activities related to certain facilities and locations for polychlorinated biphenyls, mercury, and other hazardous substances. These activities have involved the EPA and various state environmental authorities, resulting in our identification as a potentially responsible party at various Superfund waste sites. At March 31, 2017, we have accrued liabilities of $9 million for these costs. We expect that these costs will be recoverable through rates.

We also accrue environmental remediation costs for natural gas underground storage facilities, primarily related to soil and groundwater contamination. At March 31, 2017, we have accrued liabilities totaling $8 million for these costs.

Geismar Incident

On June 13, 2013, an explosion and fire occurred at our Geismar olefins plant and rendered the facility temporarily inoperable (Geismar Incident). As a result, there were two fatalities and numerous individuals (including employees and contractors) reported injuries. We are addressing the following contingent liabilities in connection with the Geismar Incident.

On October 21, 2013, the EPA issued an Inspection Report pursuant to the Clean Air Act’s Risk Management Program following its inspection of the facility on June 24 through June 28, 2013. The report notes the EPA’s preliminary determinations about the facility’s documentation regarding process safety, process hazard analysis, as well as operating procedures, employee training, and other matters. On June 16, 2014, we received a request for information related to the Geismar Incident from the EPA under Section 114 of the Clean Air Act to which we responded on August 13, 2014. The EPA could issue penalties pertaining to final determinations.

Multiple lawsuits, including class actions for alleged offsite impacts, property damage, customer claims, and personal injury, have been filed against us. The first two trials, for nine plaintiffs claiming personal injury, were held in Louisiana state court in Iberville Parish, Louisiana in September and November 2016. The juries returned adverse verdicts against Williams, our subsidiary Williams Olefins, LLC, and other defendants. To date, we have settled those cases as well as settled or agreed in principle to settle numerous other personal injury claims, and such aggregate amount greater than our $2 million retention (deductible) value has been or will be recovered from our insurers. We believe these settlements to date substantially resolve any material exposure to such claims arising from the Geismar Incident. We believe that any additional losses arising from our alleged liability will be immaterial to our expected future annual results of operations, liquidity, and financial position and will be substantially covered by our general liability insurance policy, which has an aggregate limit of $610 million applicable to this event.

Royalty Matters

Certain of our customers, including one major customer, have been named in various lawsuits alleging underpayment of royalties and claiming, among other things, violations of anti-trust laws and the Racketeer Influenced and Corrupt Organizations Act. We have also been named as a defendant in certain of these cases in Pennsylvania based on allegations that we improperly participated with that major customer in causing the alleged royalty underpayments. We believe that the claims asserted are subject to indemnity obligations owed to us by that major customer. Due to the preliminary status of the cases, we are unable to estimate a range of potential loss at this time.

Unitholder Litigation

On March 7, 2016, a purported unitholder of us filed a putative class action on behalf of certain purchasers of our units in U.S. District Court in Oklahoma. The action names as defendants, us, Williams, Williams Partners GP LLC, Alan S. Armstrong, and Donald R. Chappel and alleges violations of certain federal securities laws for failure to disclose Energy Transfer Equity, L.P.’s intention to pursue a purchase of Williams conditioned on Williams not closing the WPZ Public Unit Exchange when announcing the WPZ Public Unit Exchange. The complaint seeks, among other things, damages and an award of costs and attorneys’ fees. The plaintiff filed an amended complaint on August 31, 2016. On October 17, 2016, we requested the court dismiss the action, and on March 8, 2017, the court dismissed the complaint with prejudice. On April 7, 2017, the plaintiff filed a notice of appeal. We cannot reasonably estimate a range of potential loss at this time.

Other

In addition to the foregoing, various other proceedings are pending against us which are incidental to our operations.

Summary

We have disclosed all significant matters for which we are unable to reasonably estimate a range of possible loss. We estimate that for all other matters for which we are able to reasonably estimate a range of loss, our aggregate reasonably possible losses beyond amounts accrued are immaterial to our expected future annual results of operations, liquidity, and financial position. These calculations have been made without consideration of any potential recovery from third parties.

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Segment Disclosures

3 Months Ended

Mar. 31, 2017

Segment Reporting [Abstract]

Segment Disclosures [Text Block]

Note 10 – Segment Disclosures

Our reportable segments are Northeast G&P, Atlantic-Gulf, West, and NGL & Petchem Services. (See Note 1 – General, Description of Business, and Basis of Presentation.) Certain other corporate activities are included in Other.

Performance Measurement

We evaluate segment operating performance based upon Modified EBITDA (earnings before interest, taxes, depreciation, and amortization). This measure represents the basis of our internal financial reporting and is the primary performance measure used by our chief operating decision maker in measuring performance and allocating resources among our reportable segments. Intersegment revenues primarily represent the sale of NGLs from our natural gas processing plants to our marketing business.

We define Modified EBITDA as follows:

• Net income (loss) before:

◦ Provision (benefit) for income taxes;

◦ Interest incurred, net of interest capitalized;

◦ Equity earnings (losses);

◦ Impairment of equity-method investments;

◦ Other investing income (loss) – net;

◦ Impairment of goodwill;

◦ Depreciation and amortization expenses;

◦ Accretion expense associated with asset retirement obligations for nonregulated operations.

• This measure is further adjusted to include our proportionate share (based on ownership interest) of Modified EBITDA from our equity-method investments calculated consistently with the definition described above.

The following table reflects the reconciliation of Segment revenues to Totalrevenues as reported in the Consolidated Statement of Comprehensive Income (Loss).

	Northeast G&P		Atlantic- Gulf		West		NGL & Petchem Services		Eliminations			Total
	(Millions)
Three Months Ended March 31, 2017
Segment revenues:
Service revenues
External	$	208	$	527	$	518	$	3	$	—		$	1,256
Internal	9		9		—		—		(18		)	—
Total service revenues	217		536		518		3		(18		)	1,256
Product sales
External	60		69		405		193		—			727
Internal	8		65		51		6		(130		)	—
Total product sales	68		134		456		199		(130		)	727
Total revenues	$	285	$	670	$	974	$	202	$	(148	)	$	1,983
Three Months Ended March 31, 2016
Segment revenues:
Service revenues
External	$	216	$	471	$	531	$	8	$	—		$	1,226
Internal	3		7		—		—		(10		)	—
Total service revenues	219		478		531		8		(10		)	1,226
Product sales
External	18		36		211		163		—			428
Internal	5		33		31		5		(74		)	—
Total product sales	23		69		242		168		(74		)	428
Total revenues	$	242	$	547	$	773	$	176	$	(84	)	$	1,654

The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Comprehensive Income (Loss).

	Three Months Ended   March 31,
	2017			2016
	(Millions)
Modified EBITDA by segment:
Northeast G&P	226			220
Atlantic-Gulf	450			382
West	385			327
NGL & Petchem Services	51			26
Other	20			—
	1,132			955
Accretion expense associated with asset retirement obligations for nonregulated operations	(6		)	(7		)
Depreciation and amortization expenses	(433		)	(435		)
Equity earnings (losses)	107			97
Impairment of equity-method investments	—			(112		)
Other investing income (loss) – net	271			—
Proportional Modified EBITDA of equity-method investments	(194		)	(189		)
Interest expense	(214		)	(229		)
(Provision) benefit for income taxes	(3		)	(1		)
Net income (loss)	$	660		$	79

The following table reflects Total assets by reportable segment.  

	Total Assets
	March 31,   2017			December 31,   2016
	(Millions)
Northeast G&P	14,531			13,436
Atlantic-Gulf	14,402			14,176
West	17,171			18,479
NGL & Petchem Services	1,196			1,112
Other	243			161
Eliminations (1)	(605		)	(1,099		)
Total	$	46,938		$	46,265

(1) Eliminations primarily relate to the intercompany accounts and notes receivable generated by our cash management program.

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General, Description of Business, and Basis of Presentation Assets and Liabilities Held For Sale (Tables)

3 Months Ended

Mar. 31, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Disposal Groups, Including Discontinued Operations [Table Text Block]

The assets and liabilities of the Geismar olefins plant are presented as held for sale as of March 31, 2017. The following table presents the carrying amounts of the major classes of assets and liabilities included as part of the Geismar disposal group, which are presented within Assets held for sale and Liabilities held for sale in the Consolidated Balance Sheet. Also included in Assets held for sale in the Consolidated Balance Sheet are $24 million of assets held for sale within the West segment unrelated to the Geismar Interest and at December 31, 2016, were previously included in Other current assets and deferred charges.

	Carrying Amount
	March 31, 2017
	(Millions)
Assets:
Current assets	$	71
Property, plant, and equipment – net	901
Other noncurrent assets	27
	$	999
Liabilities:
Current liabilities	$	42
Noncurrent liabilities	1
	$	43

The following table presents the results of operations for the Geismar disposal group.

	Three Months Ended   March 31,
	2017		2016
	(Millions)
Income (loss) before income taxes of disposal group	$	23	$	18

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Variable Interest Entities (Tables)

3 Months Ended

Mar. 31, 2017

Variable Interest Entity Disclosures [Abstract]

Schedule of Variable Interest Entities [Table Text Block]

The following table presents amounts included in our Consolidated Balance Sheet that are for the use or obligation of our consolidated VIEs:

	March 31, 2017			December 31, 2016			Classification
	(Millions)
Assets (liabilities):
Cash and cash equivalents	$	101		$	82		Cash and cash equivalents
Accounts receivable	73			91			Trade accounts and other receivables
Prepaid assets	2			3			Other current assets and deferred charges
Property, plant, and equipment - net	2,990			3,024			Property, plant, and equipment - net
Intangible assets – net	1,419			1,431			Intangible assets – net of accumulated amortization
Accounts payable	(31		)	(44		)	Accounts payable – trade
Accrued liabilities	(3		)	(3		)	Other accrued liabilities
Current deferred revenue	(63		)	(63		)	Other accrued liabilities
Noncurrent asset retirement obligations	(101		)	(99		)	Asset retirement obligations
Noncurrent deferred revenue associated with customer advance payments	(320		)	(324		)	Regulatory liabilities, deferred income, and other

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Allocation of Net Income (Loss) and Distributions (Tables)

3 Months Ended

Mar. 31, 2017

Equity [Abstract]

Allocation of net income (loss) among our general partner, limited partners, and noncontrolling interests

The allocation of net income (loss) among our general partner, limited partners, and noncontrolling interests within Equity is as follows:

	Three Months Ended   March 31,
	2017		2016
	(Millions)
Net income (loss) allocated to common limited partners’ equity (1)	$	623	$	43
Net income (loss) allocated to Class B limited partners’ equity	11		1
Net income (loss) allocated to general partner’s equity (1) (2)	—		6
Net income (loss) allocated to noncontrolling interests	26		29
Net income (loss)	$	660	$	79

(1) Net income (loss) allocated to equity accounts above considers distributions paid to partners during the current reporting period, while Net income (loss) allocated within the Consolidated Statement of Comprehensive Income (Loss) considers distributions declared for the current reporting period, but paid in the subsequent period. The 2016 differences between Net income (loss) allocated to equity accounts and Net income (loss) allocated within the Consolidated Statement of Comprehensive Income (Loss) are primarily due to the timing of the waiver of IDRs associated with the Termination Agreement. (See Note 1 – General, Description of Business, and Basis of Presentation.)

(2) As part of the first quarter 2017 Financial Repositioning (see Note 1 – General, Description of Business, and Basis of Presentation), our general partner interest in us was converted to a non-economic interest and therefore no longer receives an allocation of net income.

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Other Income and Expenses (Tables)

3 Months Ended

Mar. 31, 2017

Other Income and Expenses [Abstract]

Other Income and Expenses [Table Text Block]

The following table presents certain gains or losses reflected in Other (income) expense – netwithin Costs and expenses in our Consolidated Statement of Comprehensive Income (Loss):

	Three Months Ended   March 31,
	2017			2016
	(Millions)
West
Gains on contract settlements and terminations	$	(13	)	$	—
NGL & Petchem Services
Net foreign currency exchange (gains) losses (1)	—			11

(1) Primarily relates to gains and losses incurred on foreign currency transactions and the remeasurement of U.S. dollar denominated current assets and liabilities within our former Canadian operations.

Severance and Other Related Costs [Table Text Block]

mounts by segment are as follows:

	Three Months Ended   March 31,
	2017		2016
	(Millions)
Northeast G&P	$	—	$	3
Atlantic-Gulf	—		8
West	—		10
NGL & Petchem Services	—		4
Other	9		—

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Debt and Banking Arrangements (Tables)

3 Months Ended

Mar. 31, 2017

Debt Disclosure [Abstract]

Schedule of Line of Credit Facilities [Table Text Block]

Credit Facilities

	March 31, 2017
	Stated Capacity		Outstanding
	(Millions)
Long-term credit facility (1)	$	3,500	$	—
Letters of credit under certain bilateral bank agreements			1

(1) In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program.

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Fair Value Measurements and Guarantees (Tables)

3 Months Ended

Mar. 31, 2017

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

The following table presents, by level within the fair value hierarchy, certain of our financial assets and liabilities. The carrying values of cash and cash equivalents, accounts receivable, commercial paper, and accounts payable approximate fair value because of the short-term nature of these instruments. Therefore, these assets and liabilities are not presented in the following table.

							Fair Value Measurements Using
	Carrying  Amount			Fair Value			Quoted Prices In Active  Markets for  Identical Assets (Level 1)		Significant  Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
	(Millions)
Assets (liabilities) at March 31, 2017:
Measured on a recurring basis:
ARO Trust investments	$	112		$	112		$	112	$	—		$	—
Energy derivatives assets designated as hedging instruments	5			5			5		—			—
Energy derivatives assets not designated as hedging instruments	2			2			1		—			1
Energy derivatives liabilities not designated as hedging instruments	(4		)	(4		)	—		—			(4		)
Additional disclosures:
Other receivables	5			5			5		—			—
Long-term debt	(17,065		)	(17,944		)	—		(17,944		)	—
Assets (liabilities) at December 31, 2016:
Measured on a recurring basis:
ARO Trust investments	$	96		$	96		$	96	$	—		$	—
Energy derivatives assets designated as hedging instruments	2			2			—		2			—
Energy derivatives assets not designated as hedging instruments	1			1			—		—			1
Energy derivatives liabilities not designated as hedging instruments	(6		)	(6		)	—		—			(6		)
Additional disclosures:
Other receivables	15			15			15		—			—
Long-term debt, including current portion	(18,470		)	(18,907		)	—		(18,907		)	—

Fair Value Measurements, Nonrecurring [Table Text Block]

Nonrecurring fair value measurements

The following table presents impairments of investments associated with certain nonrecurring fair value measurements within Level 3 of the fair value hierarchy.

						Impairments
						Three Months Ended March 31,
	Classification	Segment	Date of Measurement	Fair Value		2017		2016
				(Millions)
Equity-method investments (1)	Investments	West and Northeast G&P	March 31, 2016	$	1,294	$	—	$	109
Other equity-method investment	Investments	West	March 31, 2016	—		—		3
Impairment of equity-method investments						$	—	$	112

_________________

(1) Relates to West’s equity-method investment in DBJV and Northeast G&P’s equity-method investment in Laurel Mountain. Our carrying values in these equity-method investments had been written down to fair value at December 31, 2015. Our first-quarter 2016 analysis reflected higher discount rates for both of these investments, along with lower natural gas prices for Laurel Mountain. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 13.0 percent to 13.3 percent and reflected increases in our estimated cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses.

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Segment Disclosures (Tables)

3 Months Ended

Mar. 31, 2017

Segment Reporting [Abstract]

Reconciliation of revenues from segment to consolidated [Table Text Block]

The following table reflects the reconciliation of Segment revenues to Totalrevenues as reported in the Consolidated Statement of Comprehensive Income (Loss).

	Northeast G&P		Atlantic- Gulf		West		NGL & Petchem Services		Eliminations			Total
	(Millions)
Three Months Ended March 31, 2017
Segment revenues:
Service revenues
External	$	208	$	527	$	518	$	3	$	—		$	1,256
Internal	9		9		—		—		(18		)	—
Total service revenues	217		536		518		3		(18		)	1,256
Product sales
External	60		69		405		193		—			727
Internal	8		65		51		6		(130		)	—
Total product sales	68		134		456		199		(130		)	727
Total revenues	$	285	$	670	$	974	$	202	$	(148	)	$	1,983
Three Months Ended March 31, 2016
Segment revenues:
Service revenues
External	$	216	$	471	$	531	$	8	$	—		$	1,226
Internal	3		7		—		—		(10		)	—
Total service revenues	219		478		531		8		(10		)	1,226
Product sales
External	18		36		211		163		—			428
Internal	5		33		31		5		(74		)	—
Total product sales	23		69		242		168		(74		)	428
Total revenues	$	242	$	547	$	773	$	176	$	(84	)	$	1,654

Reconciliation of Modified EBITDA to Net Income (Loss) [Table Text Block]

The following table reflects the reconciliation of Modified EBITDA to Net income (loss) as reported in the Consolidated Statement of Comprehensive Income (Loss).

	Three Months Ended   March 31,
	2017			2016
	(Millions)
Modified EBITDA by segment:
Northeast G&P	226			220
Atlantic-Gulf	450			382
West	385			327
NGL & Petchem Services	51			26
Other	20			—
	1,132			955
Accretion expense associated with asset retirement obligations for nonregulated operations	(6		)	(7		)
Depreciation and amortization expenses	(433		)	(435		)
Equity earnings (losses)	107			97
Impairment of equity-method investments	—			(112		)
Other investing income (loss) – net	271			—
Proportional Modified EBITDA of equity-method investments	(194		)	(189		)
Interest expense	(214		)	(229		)
(Provision) benefit for income taxes	(3		)	(1		)
Net income (loss)	$	660		$	79

Reconciliation of Assets from Segment to Consolidated [Table Text Block]

The following table reflects Total assets by reportable segment.  

	Total Assets
	March 31,   2017			December 31,   2016
	(Millions)
Northeast G&P	14,531			13,436
Atlantic-Gulf	14,402			14,176
West	17,171			18,479
NGL & Petchem Services	1,196			1,112
Other	243			161
Eliminations (1)	(605		)	(1,099		)
Total	$	46,938		$	46,265

(1) Eliminations primarily relate to the intercompany accounts and notes receivable generated by our cash management program.

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General, Description of Business, and Basis of Presentation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions				1 Months Ended					3 Months Ended
	Feb. 10, 2017	Jan. 09, 2017	Sep. 28, 2015	Feb. 03, 2017	Jan. 31, 2017	May 31, 2016	Feb. 29, 2016	Nov. 30, 2015	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Equity Method Investments									$ 6,738		$ 6,701
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Proceeds from sales of common units									$ 2,178	$ 0
WPZ Merger Public Unit Exchange [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Termination Fee			$ 428
Maximum Reduction Of Quarterly Incentive Distributions			$ 209
Reduction in incentive distribution rights payment						$ 10	$ 209	$ 209
Financial Repositioning [Member] | The Williams Companies, Inc. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Parent, general partner ownership percentage					2.00%
Partners' Capital Account, Units, Sale of Units		277			289,000
Proceeds from sales of common units	$ 50	$ 10
Partners' Capital Account, Units, Sold in Private Placement				59,000
Shares Issued, Price Per Share				$ 36.08586
Parent, limited partner ownership percentage									74.00%
Delaware Basin Gas Gathering System [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage									50.00%
Variable Interest Entity, Primary Beneficiary [Member] | Cardinal Gas Services LLC [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage									66.00%
Variable Interest Entity, Primary Beneficiary [Member] | Gulfstar One [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage									51.00%
Variable Interest Entity, Primary Beneficiary [Member] | Constitution Pipeline Company LLC [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage									41.00%
Northeast G And P [Member] | Appalachia Midstream Services, LLC [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Subsidiary, ownership percentage									66.00%
Northeast G And P [Member] | Utica East Ohio Midstream, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage									62.00%
Northeast G And P [Member] | Laurel Mountain Midstream, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage									69.00%
Northeast G And P [Member] | Caiman Energy II, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage									58.00%
Atlantic Gulf [Member] | Gulfstar One [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage									51.00%
Atlantic Gulf [Member] | Constitution Pipeline Company LLC [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Variable Interest Entity Ownership Percentage									41.00%
Atlantic Gulf [Member] | Gulfstream Natural Gas System, L.L.C. [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage									50.00%
Atlantic Gulf [Member] | Discovery Producer Services LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage									60.00%
NGL And Petchem Services [Member] | Geismar [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Subsidiary, ownership percentage									88.50%
NGL And Petchem Services [Member] | Conway Fractionator [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Subsidiary, ownership percentage									50.00%
NGL And Petchem Services [Member] | Overland Pass Pipeline Company LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage									50.00%
West [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Goodwill									$ 47
Central [Member] | Delaware Basin Gas Gathering System [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage									50.00%

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General, Description of Business, and Basis of Presentation Assets and Liabilities Held For Sale (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Liabilities, Current	$ 43	$ 0
Williams Olefins, L.L.C. [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Other Assets, Current	71
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment	901
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent	27
Disposal Group, Including Discontinued Operation, Assets, Current	999
Disposal Group, Including Discontinued Operation, Other Liabilities, Current	42
Disposal Group, Including Discontinued Operation, Liabilities, Noncurrent	1
Disposal Group, Including Discontinued Operation, Liabilities, Current	43
West [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets Held-for-sale, Not Part of Disposal Group	$ 24

XML

General, Description of Business, and Basis of Presentation Results of Operations For the Disposal Group (Details) - Williams Olefins, L.L.C. [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Apr. 17, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (Loss) from Individually Significant Component Disposed of or Held-for-sale, Excluding Discontinued Operations, before Income Tax	$ 23	$ 18
Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Consideration			$ 2,100

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Variable Interest Entities (Details) - Variable Interest Entity, Primary Beneficiary [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Cash and Cash Equivalents [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 101	$ 82
Accounts Receivable [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	73	91
Prepaid Assets [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	2	3
Property Plant And Equipment, net [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	2,990	3,024
Intangible assets, net [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Assets	1,419	1,431
Accounts payable [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(31)	(44)
Accrued liabilities [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(3)	(3)
Current deferred revenue [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(63)	(63)
Noncurrent Asset Retirement Obligation Costs [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	(101)	(99)
Noncurrent deferred revenue associated with customer advance payments [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	$ (320)	$ (324)
Gulfstar One [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	51.00%
Constitution Pipeline Company LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	41.00%
Constitution Pipeline Company LLC [Member] | Estimated Remaining Construction Costs For Variable Interest Entity [Member]
Variable Interest Entity [Line Items]
Other commitment	$ 691
Constitution Pipeline Company LLC [Member] | Property Plant And Equipment, net [Member]
Variable Interest Entity [Line Items]
Capitalized Project Development Costs	$ 381
Cardinal Gas Services LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	66.00%
Jackalope Gas Gathering Services LLC [Member]
Variable Interest Entity [Line Items]
Variable Interest Entity Ownership Percentage	50.00%

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Allocation of Net Income (Loss) and Distributions (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended				4 Months Ended
	Mar. 31, 2017		Mar. 31, 2016		Apr. 24, 2017
Allocation of net income:
Net income (loss) allocated to common limited partners' equity	$ 623		$ 43	[1]
Net income (loss) allocated to Class B limited partners' equity	11		1
Net income (loss) allocated to general partner's equity	0	[2]	6	[1]
Net income (loss) allocated to noncontrolling interests	26		29
Net income (loss)	$ 660		$ 79
Distributions Made to Members or Limited Partners [Abstract]
Per Unit Distribution (Declared)	$ 0.60		$ 0.85
Subsequent Event [Member]
Distributions Made to Members or Limited Partners [Abstract]
Payment Date					May 12, 2017
Per Unit Distribution (Declared)					$ 0.60
Class B Units Issued In Lieu Of Cash Distributions					251,859

[1] Net income (loss) allocated to equity accounts above considers distributions paid to partners during the current reporting period, while Net income (loss) allocated within the Consolidated Statement of Comprehensive Income (Loss) considers distributions declared for the current reporting period, but paid in the subsequent period. The 2016 differences between Net income (loss) allocated to equity accounts and Net income (loss) allocated within the Consolidated Statement of Comprehensive Income (Loss) are primarily due to the timing of the waiver of IDRs associated with the Termination Agreement. (See Note 1 – General, Description of Business, and Basis of Presentation.)

[2] As part of the first quarter 2017 Financial Repositioning (see Note 1 – General, Description of Business, and Basis of Presentation), our general partner interest in us was converted to a non-economic interest and therefore no longer receives an allocation of net income.

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Investing Activities (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of Equity Method Investments	$ 200	$ 0
Gain on sale of an equity-method investment interest	269	0
Impairment of equity-method investments	0	112
Delaware Basin Gas Gathering System [Member]
Schedule of Equity Method Investments [Line Items]
Gain on sale of an equity-method investment interest	$ 269
Impairment of equity-method investments		59
Equity Method Investment, Ownership Percentage	50.00%
Appalachia Midstream Services, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	66.00%
Ranch Westex JV LLC [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of Equity Method Investments	$ 45
Laurel Mountain Midstream, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Impairment of equity-method investments		$ 50
Northeast G And P [Member] | Laurel Mountain Midstream, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	69.00%
West [Member] | Delaware Basin Gas Gathering System [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from Sale of Equity Method Investments	$ 155
Appalachia Midstream Services, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Investments, Fair Value Disclosure	$ 1,100
Fair Value Inputs, Discount Rate	9.50%

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Other Income and Expenses (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Debt Instrument, Unamortized Discount (Premium), Net		$ 30
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums		53
Debt Instrument, Unamortized Premium		23
Other income (expense) - net [Member] | West [Member]
Segment Reporting Information [Line Items]
Gain (Loss) on Contract Termination		(13)	$ 0
Other income (expense) - net [Member] | NGL & Petchem Services [Member]
Segment Reporting Information [Line Items]
Net foreign currency exchange (gains) losses (1)	[1]	0	$ 11
Selling, general, and administrative expenses and Operating and maintenance expenses [Member]
Segment Reporting Information [Line Items]
Approximate percentage of workforce reductions			10.00%
Severance and other related costs		9	$ 25
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | Northeast G&P [Member]
Segment Reporting Information [Line Items]
Severance and other related costs		0	3
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | Atlantic-Gulf [Member]
Segment Reporting Information [Line Items]
Severance and other related costs		0	8
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | West [Member]
Segment Reporting Information [Line Items]
Severance and other related costs		0	10
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | NGL & Petchem Services [Member]
Segment Reporting Information [Line Items]
Severance and other related costs		0	4
Selling, general, and administrative expenses and Operating and maintenance expenses [Member] | Other [Member]
Segment Reporting Information [Line Items]
Severance and other related costs		9	0
Service revenues [Member] | Atlantic-Gulf [Member]
Segment Reporting Information [Line Items]
Revenue adjustment associated with litigation			15
Other income (expense) - net [Member] | Atlantic-Gulf [Member]
Segment Reporting Information [Line Items]
Allowance for funds used during construction, capitalized cost of equity		18	$ 17
6.125% Senior Unsecured Notes due 2022 [Member] | Williams Partners L.P. [Member]
Segment Reporting Information [Line Items]
Long-term debt retired		$ 750
Long-term debt interest rate		6.125%

[1] Primarily relates to gains and losses incurred on foreign currency transactions and the remeasurement of U.S. dollar denominated current assets and liabilities within our former Canadian operations.

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Debt and Banking Arrangements Long-term Debt Issuances and Retirements (Details 1) - USD ($) $ in Millions			3 Months Ended
	Apr. 15, 2017	Feb. 01, 2017	Mar. 31, 2017	Apr. 03, 2017
Williams Partners L.P. [Member] | 6.125% Senior Unsecured Notes due 2022 [Member]
Debt Instrument [Line Items]
Long-term debt interest rate			6.125%
Long-term debt retired			$ 750
Williams Partners L.P. [Member] | 7.25% Senior Unsecured Notes due 2017 [Member]
Debt Instrument [Line Items]
Long-term debt interest rate		7.25%
Long-term debt retired		$ 600
Subsequent Event [Member] | Northwest Pipeline LLC [Member] | 4% Senior Unsecured Notes Due 2027 [Member]
Debt Instrument [Line Items]
Long-term debt face amount				$ 250
Long-term debt interest rate				4.00%
Additional interest rate accrued for default of registration rights agreements first period				0.25%
Additional interest rate accrued for default of registration rights agreements each subsequent period				0.25%
Maximum additional interest rate accrued for default of registration rights agreements all periods				0.50%
Subsequent Event [Member] | Northwest Pipeline LLC [Member] | 5.95% Senior Unsecured Notes due 2017 [Member]
Debt Instrument [Line Items]
Long-term debt interest rate	5.95%
Long-term debt retired	$ 185

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Debt and Banking Arrangements Credit Facilities and Commercial Paper (Details 2) - USD ($) $ in Millions		Mar. 31, 2017	Dec. 31, 2016
Credit Facility and Commercial Paper [Line Items]
Commercial paper, outstanding		$ 0	$ 93
Williams Partners L.P. [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, capacity	[1]	3,500
Credit facility, loans outstanding	[1]	0
Williams Partners L.P. [Member] | Commercial Paper [Member]
Credit Facility and Commercial Paper [Line Items]
Commercial paper, outstanding		0
Credit facility, capacity		3,000
Williams Partners L.P. [Member] | Letters Of Credit Under Certain Bilateral Bank Agreements [Member]
Credit Facility and Commercial Paper [Line Items]
Credit facility, letters of credit outstanding		$ 1

[1] In managing our available liquidity, we do not expect a maximum outstanding amount in excess of the capacity of our credit facility inclusive of any outstanding amounts under our commercial paper program.

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Partners' Capital (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended
	Feb. 28, 2017	Mar. 31, 2017	Mar. 31, 2016
Business Acquisition [Line Items]
Proceeds from sales of common units		$ 2,178	$ 0
Dividend Reinvestment Program [Member]
Business Acquisition [Line Items]
Shares Issued, Price Per Share	$ 39.76
Partners' Capital Account, Units, Sold in Private Placement	395,395
Proceeds from sales of common units	$ 16

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Fair Value Measurements Recurring Measurements and Additional (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Additional disclosures:
Fair Value, Level 1 to Level 2 Transfers, Amount	$ 0		$ 0
Fair Value, Level 2 to Level 1 Transfers, Amount	0		$ 0
Carrying Amount [Member]
Additional disclosures:
Other receivables	5	$ 15
Long-term debt	(17,065)	(18,470)
Fair Value [Member]
Additional disclosures:
Other receivables	5	15
Long-term debt	(17,944)	(18,907)
Level 1 [Member]
Additional disclosures:
Other receivables	5	15
Long-term debt	0	0
Level 2 [Member]
Additional disclosures:
Other receivables	0	0
Long-term debt	(17,944)	(18,907)
Level 3 [Member]
Additional disclosures:
Other receivables	0	0
Long-term debt	0	0
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member]
Measured on a recurring basis:
ARO Trust investments	112	96
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	5	2
Fair Value, Measurements, Recurring [Member] | Carrying Amount [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	2	1
Energy derivatives liabilities	(4)	(6)
Fair Value, Measurements, Recurring [Member] | Fair Value [Member]
Measured on a recurring basis:
ARO Trust investments	112	96
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	5	2
Fair Value, Measurements, Recurring [Member] | Fair Value [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	2	1
Energy derivatives liabilities	(4)	(6)
Fair Value, Measurements, Recurring [Member] | Level 1 [Member]
Measured on a recurring basis:
ARO Trust investments	112	96
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	5	0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	1	0
Energy derivatives liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Measured on a recurring basis:
ARO Trust investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0	2
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0	0
Energy derivatives liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Measured on a recurring basis:
ARO Trust investments	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	0	0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Not Designated as Hedging Instrument [Member]
Measured on a recurring basis:
Energy derivatives assets	1	1
Energy derivatives liabilities	$ (4)	$ (6)

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Fair Value Measurements Nonrecurring Measurements (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of equity-method investments		$ 0	$ 112
Delaware Basin Gas Gathering System [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of equity-method investments			59
Fair Value, Measurements, Nonrecurring [Member] | Impairment Of Equity-Method Investments [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of equity-method investments		0	112
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | WestAndNortheastGP [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Fair value of investment	[1]		$ 1,294
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | WestAndNortheastGP [Member] | Minimum [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Discount rate			13.00%
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | WestAndNortheastGP [Member] | Maximum [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Discount rate			13.30%
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Investments [Member] | West [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Fair value of investment			$ 0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Equity-Method Investments [Member] | WestAndNortheastGP [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of equity-method investments	[1]	0	109
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member] | Impairment Of Equity-Method Investments [Member] | West [Member]
Fair Value Assets Measured On Nonrecurring Basis [Abstract]
Impairment of equity-method investments		$ 0	$ 3

[1] Relates to West’s equity-method investment in DBJV and Northeast G&P’s equity-method investment in Laurel Mountain. Our carrying values in these equity-method investments had been written down to fair value at December 31, 2015. Our first-quarter 2016 analysis reflected higher discount rates for both of these investments, along with lower natural gas prices for Laurel Mountain. We estimated the fair value of these investments using an income approach based on expected future cash flows and appropriate discount rates. The determination of estimated future cash flows involved significant assumptions regarding gathering volumes and related capital spending. Discount rates utilized ranged from 13.0 percent to 13.3 percent and reflected increases in our estimated cost of capital, revised estimates of expected future cash flows, and risks associated with the underlying businesses.

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Contingent Liabilities (Details) $ in Millions	Mar. 31, 2017 USD ($)
Contingent Liabilities [Line Items]
Accrued environmental loss liabilities	$ 17
Gas Pipeline [Member]
Contingent Liabilities [Line Items]
Accrued environmental loss liabilities	9
Natural Gas Underground Storage Facilities [Member]
Contingent Liabilities [Line Items]
Accrued environmental loss liabilities	8
NGL And Petchem Services [Member] | General Liability Coverage [Member] | Geismar Incident [Member]
Contingent Liabilities [Line Items]
Insurance deductibles	2
Aggregate limit of insurance	$ 610

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Segment Disclosures Reconciliation of Segment Revenues to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment revenues [Line Items]
Service revenues	$ 1,256	$ 1,226
Product sales	727	428
Total revenues	1,983	1,654
Northeast G&P [Member]
Segment revenues [Line Items]
Service revenues	208	216
Product sales	60	18
Atlantic-Gulf [Member]
Segment revenues [Line Items]
Service revenues	527	471
Product sales	69	36
West [Member]
Segment revenues [Line Items]
Service revenues	518	531
Product sales	405	211
NGL & Petchem Services [Member]
Segment revenues [Line Items]
Service revenues	3	8
Product sales	193	163
Intersegment Eliminations [Member]
Segment revenues [Line Items]
Service revenues	(18)	(10)
Product sales	(130)	(74)
Total revenues	(148)	(84)
Intersegment Eliminations [Member] | Northeast G&P [Member]
Segment revenues [Line Items]
Service revenues	(9)	(3)
Product sales	(8)	(5)
Intersegment Eliminations [Member] | Atlantic-Gulf [Member]
Segment revenues [Line Items]
Service revenues	(9)	(7)
Product sales	(65)	(33)
Intersegment Eliminations [Member] | West [Member]
Segment revenues [Line Items]
Service revenues	0	0
Product sales	(51)	(31)
Intersegment Eliminations [Member] | NGL & Petchem Services [Member]
Segment revenues [Line Items]
Service revenues	0	0
Product sales	(6)	(5)
Operating Segments [Member] | Northeast G&P [Member]
Segment revenues [Line Items]
Service revenues	217	219
Product sales	68	23
Total revenues	285	242
Operating Segments [Member] | Atlantic-Gulf [Member]
Segment revenues [Line Items]
Service revenues	536	478
Product sales	134	69
Total revenues	670	547
Operating Segments [Member] | West [Member]
Segment revenues [Line Items]
Service revenues	518	531
Product sales	456	242
Total revenues	974	773
Operating Segments [Member] | NGL & Petchem Services [Member]
Segment revenues [Line Items]
Service revenues	3	8
Product sales	199	168
Total revenues	$ 202	$ 176

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Segment Disclosures Reconciliation of Segment Modified EBITDA to Consolidated Net Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reconciliation of Modified EBITDA to net income (loss):
Modified EBITDA Earnings (Loss)	$ 1,132	$ 955
Asset Retirement Obligation Accretion Expense For Nonregulated Operations	(6)	(7)
Depreciation and amortization expenses	(433)	(435)
Equity earnings (losses)	107	97
Impairment of equity-method investments	0	(112)
Other investing income (loss) - net	271	0
Proportional Modified EBITDA of Equity-Method Investments	(194)	(189)
Interest Expense	(214)	(229)
(Provision) benefit for income taxes	(3)	(1)
Net income (loss)	660	79
Operating Segments [Member] | Northeast G&P [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified EBITDA Earnings (Loss)	226	220
Operating Segments [Member] | Atlantic Gulf [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified EBITDA Earnings (Loss)	450	382
Operating Segments [Member] | West [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified EBITDA Earnings (Loss)	385	327
Operating Segments [Member] | NGL And Petchem Services [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified EBITDA Earnings (Loss)	51	26
Other [Member] | Other [Member]
Reconciliation of Modified EBITDA to net income (loss):
Modified EBITDA Earnings (Loss)	$ 20	$ 0

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Segment Disclosures Reconciliation of Segment Assets to Consolidated (Details) - USD ($) $ in Millions		Mar. 31, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		$ 46,938	$ 46,265
Northeast G&P [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		14,531	13,436
Atlantic-Gulf [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		14,402	14,176
West [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		17,171	18,479
NGL & Petchem Services [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		1,196	1,112
Other corporate assets [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets		243	161
Eliminations [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	[1]	$ (605)	$ (1,099)

[1] Eliminations primarily relate to the intercompany accounts and notes receivable generated by our cash management program.