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

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

Commission File Number 1-7414

(Exact name of registrant as specified in its charter)

DELAWARE		26-1157701
(State or other jurisdiction of incorporation or organization)		(I.R.S. Employer Identification No.)
295 Chipeta Way, Salt Lake City, Utah		84108
(Address of principal executive offices)		(Zip Code)

(801) 583-8800

No Change

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 o

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

Yes o No o

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

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

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Yes o No þ

THE REGISTRANT MEETS THE CONDITIONS SET FORTH IN GENERAL INSTRUCTION (H)(1)(a) AND (b) OF FORM 10-Q AND IS THEREFORE FILING THIS FORM 10-Q WITH THE REDUCED DISCLOSURE FORMAT.

 

 

     NORTHWEST PIPELINE GP
FORM 10-Q

TABLE OF CONTENTS

		Page
PART I. FINANCIAL INFORMATION:
Item 1. Financial Statements -
Statement of Income, three months ended March 31, 2011 and 2010			1
Balance Sheet as of March 31, 2011 and December 31, 2010			2
Statement of Cash Flows, three months ended March 31, 2011 and 2010			4
Notes to Financial Statements			5
Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations			9
Item 4. Controls and Procedures			10
PART II. OTHER INFORMATION:
Item 1. Legal Proceedings			11
Item 1A. Risk Factors			11
Item 6. Exhibits			11
EX-31.A
EX-31.B
EX-32.A

Forward Looking Statements

     Certain matters contained in this report include “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. 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. We make these forward-looking statements in reliance on the safe harbor protections provided under the Private Securities Litigation Reform Act of 1995.

     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” or other similar expressions. These statements are based on management’s beliefs and assumptions and on information currently available to management and include, among others, statements regarding:

	•		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;
	•		Rate case filings; and
	•		Natural gas prices and demand.

     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:

	•		Availability of supplies (including the uncertainties inherent in assessing and estimating future natural gas reserves), market demand, volatility of prices, and the availability and cost of capital;
	•		Inflation, interest rates, and general economic conditions (including future disruptions and volatility in the global credit markets and the impact of these events on our customers and suppliers);
	•		The strength and financial resources of our competitors;
	•		Development of alternative energy sources;
	•		The impact of operational and development hazards;
	•		Costs of, changes in, or the results of laws, government regulations (including climate change legislation), environmental liabilities, litigation and rate proceedings;
	•		Our allocated costs for defined benefit pension plans and other postretirement benefit plans sponsored by our affiliates;
	•		Changes in maintenance and construction costs;
	•		Changes in the current geopolitical situation;
	•		Our exposure to the credit risk of our customers;
	•		Risks related to strategy and financing, including restrictions stemming from our debt agreements, future changes in our credit ratings, and the availability and cost of credit;
	•		Risks associated with future weather conditions;
	•		Acts of terrorism; and
	•		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 to 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.

     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 for the year ended December 31, 2010, and Part II, Item 1A. Risk Factors of this Form 10-Q.

PART I. FINANCIAL INFORMATION

Item 1. Financial Statements

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STATEMENT OF INCOME
(Thousands of Dollars)
(Unaudited)

		Three Months Ended
		March 31,
		2011				2010
OPERATING REVENUES		$	109,919			$	106,110
OPERATING EXPENSES:
General and administrative			15,423				14,140
Operation and maintenance			15,273				15,501
Depreciation			22,558				21,970
Regulatory credits			(267	)			(460	)
Taxes, other than income taxes			5,700				4,668
Total operating expenses			58,687				55,819
Operating income			51,232				50,291
OTHER INCOME — net:
Interest income —
Affiliated			3				4
Other			—				1
Allowance for equity funds used during construction			120				277
Miscellaneous other income (expense), net			(113	)			(620	)
Total other income (expense) — net			10				(338	)
INTEREST CHARGES:
Interest on long-term debt			11,110				11,128
Other interest			510				1,079
Allowance for borrowed funds used during construction			(54	)			(137	)
Total interest charges			11,566				12,070
INCOME BEFORE INCOME TAXES			39,676				37,883
INCOME TAXES			(7	)			—
NET INCOME		$	39,683			$	37,883

See accompanying notes.

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BALANCE SHEET

(Thousands of Dollars)

(Unaudited)

		March 31,				December 31,
		2011				2010
ASSETS
CURRENT ASSETS:
Cash and cash equivalents		$	69			$	5
Advances to affiliate			83,162				45,045
Accounts receivable -
Trade			36,395				38,515
Affiliated companies			2,102				2,118
Materials and supplies, less reserves of $7 at March 31, 2011 and $613 at December 31, 2010			11,383				11,719
Exchange gas due from others			1,579				2,323
Exchange gas offset			2,795				3,854
Prepayments and other			3,018				3,415
Total current assets			140,503				106,994
PROPERTY, PLANT AND EQUIPMENT, at cost			2,968,501				2,965,097
Less — Accumulated depreciation			1,034,919				1,017,634
Total property, plant and equipment, net			1,933,582				1,947,463
OTHER ASSETS:
Deferred charges			12,026				11,817
Regulatory assets			59,884				60,176
Total other assets			71,910				71,993
Total assets		$	2,145,995			$	2,126,450

See accompanying notes.

NORTHWEST PIPELINE GP
BALANCE SHEET
(Thousands of Dollars)
(Unaudited)

		March 31,				December 31,
		2011				2010
LIABILITIES AND OWNERS’ EQUITY
CURRENT LIABILITIES:
Accounts payable -
Trade		$	4,633			$	13,177
Affiliated companies			9,019				10,105
Accrued liabilities -
Taxes, other than income taxes			14,012				10,186
Interest			15,155				4,045
Exchange gas due to others			8,439				13,115
Other			4,612				4,245
Total current liabilities			55,870				54,873
LONG-TERM DEBT			693,683				693,634
DEFERRED CREDITS AND OTHER NONCURRENT LIABILITIES			89,679				88,347
CONTINGENT LIABILITIES AND COMMITMENTS
OWNERS’ EQUITY:
Owners’ capital			1,050,362				1,046,862
Retained earnings			256,079				242,396
Accumulated other comprehensive income			322				338
Total owners’ equity			1,306,763				1,289,596
Total liabilities and owners’ equity		$	2,145,995			$	2,126,450

See accompanying notes.

NORTHWEST PIPELINE GP

STATEMENT OF CASH FLOWS

(Thousands of Dollars)

(Unaudited)

		Three Months Ended
		March 31
		2011				2010
OPERATING ACTIVITIES:
Net income		$	39,683			$	37,883
Adjustments to reconcile to net cash provided by operating activities -
Depreciation			22,558				21,970
Regulatory credits			(267	)			(460	)
Amortization of deferred charges and credits			425				1,251
Allowance for equity funds used during construction			(120	)			(277	)
Cash provided (used) by changes in current assets and liabilities:
Trade accounts receivable			2,120				2,411
Affiliated receivables			16				3,953
Exchange gas due from others			4,675				2,362
Materials and supplies			336				2
Other current assets			397				381
Trade accounts payable			(3,656	)			(3,503	)
Affiliated payables			(1,086	)			(12,225	)
Exchange gas due to others			(4,676	)			(2,361	)
Other accrued liabilities			15,302				14,439
Changes in noncurrent assets and liabilities:
Deferred charges			(1,179	)			(912	)
Other deferred credits			1,399				1,632
Net cash provided by operating activities			75,927				66,546
FINANCING ACTIVITIES:
Proceeds from issuance of long-term debt			—				8,000
Capital contribution from parent			3,500				4,000
Distributions paid			(26,000	)			(75,280	)
Other			(2,302	)			(2,613	)
Net cash used in financing activities			(24,802	)			(65,893	)
INVESTING ACTIVITIES:
Property, plant and equipment -
Capital expenditures*			(13,820	)			(10,408	)
Proceeds from sales			876				24
Repayments from (advances to) affiliates			(38,117	)			9,379
Net cash used in investing activities			(51,061	)			(1,005	)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS			64				(352	)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD			5				402
CASH AND CASH EQUIVALENTS AT END OF PERIOD		$	69			$	50
*     Increases to property, plant and equipment			(11,234	)			(6,691	)
Changes in related accounts payable and accrued liabilities			(2,586	)			(3,717	)
Capital expenditures			(13,820	)			(10,408	)

See accompanying notes.

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NOTES TO FINANCIAL STATEMENTS

1. BASIS OF PRESENTATION

General

     The accompanying interim financial statements do not include all the notes in our annual financial statements, and therefore, should be read in conjunction with the financial statements and notes thereto in our 2010 Annual Report on Form 10-K. The accompanying unaudited financial statements include all adjustments both normal recurring and others which, in the opinion of our management, are necessary to present fairly our financial position at March 31, 2011, and results of operations and cash flows for the three months ended March 31, 2011 and 2010.

     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 financial statements and accompanying notes. Actual results could differ from those estimates.

     In this report, Northwest Pipeline GP (Northwest) is at times referred to in the first person as “we”, “us” or “our.”

2. CONTINGENT LIABILITIES AND COMMITMENTS

Environmental Matters

     We are subject to the National Environmental Policy Act and other federal and state legislation regulating the environmental aspects of our business. Except as discussed below, our management believes that we are in substantial compliance with existing environmental requirements. Environmental expenditures are expensed or capitalized depending on their future economic benefit and potential for rate recovery. We believe that, with respect to any expenditures required to meet applicable standards and regulations, the Federal Energy Regulatory Commission (FERC) would grant the requisite rate relief so that substantially all of such expenditures would be permitted to be recovered through rates. We believe that compliance with applicable environmental requirements is not likely to have a material effect upon our financial position or results of operations.

     Beginning in the mid-1980s, we evaluated many of our facilities for the presence of toxic and hazardous substances to determine to what extent, if any, remediation might be necessary. We identified polychlorinated biphenyl (PCB) contamination in air compressor systems, soils and related properties at certain compressor station sites. Similarly, we identified hydrocarbon impacts at these facilities due to the former use of earthen pits and mercury contamination at certain natural gas metering sites. The PCBs were remediated pursuant to a Consent Decree with the U.S. Environmental Protection Agency (EPA) in the late 1980s, and we conducted a voluntary clean-up of the hydrocarbon and mercury impacts in the early 1990s. In 2005, the Washington Department of Ecology required us to re-evaluate our previous mercury clean-ups in Washington. Currently, we are conducting assessment and remediation activities for mercury and other constituents to bring the sites up to Washington’s current environmental standards. At March 31, 2011, we had accrued liabilities totaling approximately $8.4 million for these costs which are expected to be incurred through 2015. We are conducting environmental assessments and implementing a variety of remedial measures that may result in increases or decreases in the total estimated costs.

     We are also subject to the Federal Clean Air Act (the Act) and to the Federal Clean Air Act Amendments of 1990, which added significantly to the existing requirements established by the Act.

     In March 2008, the EPA promulgated a new, lower National Ambient Air Quality Standard (NAAQS) for ground-level ozone. Within two years, the EPA was expected to designate new eight-hour ozone non-attainment areas. However, in September 2009, the EPA announced it would reconsider the 2008 NAAQS for ground-level ozone to ensure that the standards were clearly grounded in science, and were protective of both public health and the environment. As a result, the EPA delayed designation of new eight-hour ozone non-attainment areas under the 2008 standards until the reconsideration is complete. In January 2010, the EPA proposed to further reduce the ground-level ozone NAAQS from the March 2008 levels. The EPA currently

NORTHWEST PIPELINE GP

NOTES TO FINANCIAL STATEMENTS

anticipates finalization of the new ground-level ozone standard in the third quarter of 2011. Designation of new eight-hour ozone non-attainment areas are expected to result in additional federal and state regulatory actions that will likely impact our operations and increase the cost of additions to property, plant and equipment. We are unable at this time to estimate the cost of additions that may be required to meet the new regulation.

     Additionally, in August 2010, the EPA promulgated National Emission Standards for hazardous air pollutants (NESHAP) regulations that will impact our operations. The emission control additions required to comply with hazardous air pollutant regulations are estimated to include costs in the range of $6 million to $9 million through 2013, the compliance date.

     Furthermore, the EPA promulgated the Greenhouse Gas (GHG) Mandatory Reporting Rule on October 30, 2009, which requires facilities that emit 25,000 metric tons or more carbon dioxide (CO₂) equivalent per year from stationary fossil-fuel combustion sources to report GHG emissions to the EPA annually beginning March 31, 2011 for calendar year 2010. On March 18, 2011, the EPA extended this reporting deadline to September 30, 2011. On November 30, 2010, the EPA issued additional regulations that expand the scope of the Mandatory Reporting Rule to include fugitive and vented greenhouse gas emissions effective January 1, 2011. Facilities that emit 25,000 metric tons or more CO₂ equivalent per year from stationary fossil-fuel combustion and fugitive/vented sources combined will be required to report GHG combustion and fugitive/vented emissions to the EPA annually beginning March 31, 2012 for calendar year 2011. Compliance with this reporting obligation is estimated to cost $3 million to $5 million over the next four to five years.

     In February 2010, the EPA promulgated a final rule establishing a new one-hour nitrogen dioxide (NO₂) NAAQS. The effective date of the new NO₂ standard was April 12, 2010. This new standard is subject to numerous challenges in the federal court. We are unable at this time to estimate the cost of additions that may be required to meet this new regulation.

Safety Matters

     Pipeline Integrity Regulations We have developed an Integrity Management Program that we believe meets the United States Department of Transportation Pipeline and Hazardous Materials Safety Administration final rule that was issued pursuant to the requirements of the Pipeline Safety Improvement Act of 2002. The rule requires gas pipeline operators to develop an integrity management program for transmission pipelines that could affect high consequence areas in the event of pipeline failure. The Integrity Management Program includes a baseline assessment plan along with periodic reassessments to be completed within required timeframes. In meeting the integrity regulations, we have identified high consequence areas and developed our baseline assessment plan. We are on schedule to complete the required assessments within the required timeframes. Currently, we estimate that the cost to complete the required initial assessments over the period of 2011 through 2012 and associated remediation will be primarily capital in nature and range between $50 million and $60 million. Ongoing periodic reassessments and initial assessments of any new high consequence areas will be completed within the timeframes required by the rule. Management considers the costs associated with compliance with the rule to be prudent costs incurred in the ordinary course of business and, therefore, recoverable through our rates.

Other Matters

     Various other proceedings are pending against us incidental to our operations.

Summary

     Litigation, arbitration, regulatory matters, environmental matters, and safety matters are subject to inherent uncertainties. Were an unfavorable ruling to occur, there exists the possibility of a material adverse impact on the results of operations in the period in which the ruling occurs. Management, including internal counsel, currently believes that the ultimate resolution of the foregoing matters, taken as a whole and after consideration of amounts accrued, insurance coverage, recovery from customers or other indemnification arrangements, will not have a material adverse effect on our future liquidity or financial position.

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NOTES TO FINANCIAL STATEMENTS

Cash Distributions to Partners

     During the three months ended March 31, 2011, we declared and paid equity distributions of $26.0 million to WPZ. During April 2011, we declared and paid equity distributions of $38.0 million to WPZ.

3. DEBT AND FINANCING ARRANGEMENTS

Revolving Credit and Letter of Credit Facility

     We participate in a $1.75 billion three-year senior unsecured revolving credit facility (Credit Facility) with WPZ and Transcontinental Gas Pipe Line Company, LLC (Transco), as co-borrowers, and Citibank, N.A., as administrative agent, and certain other lenders named therein. The full amount of the Credit Facility is available to WPZ, and may, under certain conditions, be increased by up to an additional $250 million. We may borrow up to $400 million under the Credit Facility to the extent not otherwise utilized by WPZ and Transco. At March 31, 2010, the full $400 million under the Credit Facility was available.

4. FINANCIAL INSTRUMENTS

Fair Value of Financial Instruments

     The following methods and assumptions were used to estimate the fair value of each class of financial instruments for which it is practicable to estimate that value:

Cash, cash equivalents and advances to affiliate — The carrying amounts of these items approximates their fair value.

Long-term debt — The fair value of our publicly traded long-term debt is valued using indicative period-end traded bond market prices. The carrying amount and estimated fair value of our long-term debt, including current maturities, were $693.7 million and $793.8 million, respectively, at March 31, 2011, and $693.6 million and $796.1 million, respectively, at December 31, 2010.

5. TRANSACTIONS WITH AFFILIATES

     We are a participant in WPZ’s cash management program. At March 31, 2011, the advances due to us by WPZ totaled $83.2 million. These advances are represented by demand notes. The interest rate on these intercompany demand notes is based upon the overnight investment rate paid on WPZ’s excess cash, which was approximately 0.02 percent at March 31, 2011. We received interest income from advances to our affiliates of $3 thousand and $4 thousand during the three months ended March 31, 2011 and 2010, respectively. Such interest income is included in “Other Income — net: Interest income — Affiliated” on the accompanying Statement of Income.

     Williams charges its subsidiary companies for management services provided by it and other affiliated companies. Such corporate expenses charged by Williams, WPZ, and other affiliated companies were $9.3 million and $8.4 million for the three months ended March 31, 2011 and 2010, respectively. These expenses are included in “General and administrative expense” on the accompanying Statement of Income. Management considers the cost of these services to be reasonable.

     Northwest has no employees. Services are provided to us by an affiliate, Northwest Pipeline Services LLC (NPS). In return, we reimburse NPS for all direct and indirect expenses it incurs or payments it makes (including salary, bonus, incentive compensation, pension and other benefits) in connection with these services. We were billed $15.1 million and $13.4 million in the three months ended March 31, 2011 and 2010, respectively. Such expenses are primarily included in “General and administrative” and “Operation and maintenance” expenses on the accompanying Statement of Income.

     During the periods presented, our revenues include transportation transactions and rental of communication facilities with subsidiaries of Williams. Combined revenues for these activities totaled $5.9

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NOTES TO FINANCIAL STATEMENTS

million and $0.7 million for the three months ended March 31, 2011 and 2010, respectively.

     We have entered into various other transactions with certain related parties, the amounts of which were not significant. These transactions and the above-described transactions are made on the basis of commercial relationships and prevailing market prices or general industry practices.

6. COMPREHENSIVE INCOME

     Comprehensive income is as follows:

		Three Months Ended
		March 31,
		2011				2010
		(Thousands of Dollars)
Net income		$	39,683			$	37,883
Amortization of cash flow hedges			(15	)			(15	)
Total comprehensive income		$	39,668			$	37,868

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

GENERAL

     Unless indicated otherwise, the following discussion should be read in conjunction with the consolidated financial statements and notes thereto included within Item 8 of our 2010 Annual Report on Form 10-K and with the financial statements and notes thereto contained within this Form 10-Q.

RESULTS OF OPERATIONS

ANALYSIS OF FINANCIAL RESULTS

     This analysis discusses financial results of our operations for the three-month periods ended March 31, 2011 and 2010. Variances due to changes in natural gas prices and transportation volumes have little impact on revenues, because under our rate design methodology, the majority of overall cost of service is recovered through firm capacity reservation charges in our transportation rates.

Three Months Ended March 31, 2011 Compared to Three Months Ended March 31, 2010

     Our operating revenues increased $3.8 million, or 4 percent. This increase is primarily attributed to higher reservation charges due primarily to the Sundance Trail Expansion Project that was put into service on November 1, 2010.

     Our transportation service accounted for 97 percent and 96 percent of our operating revenues for the three-months ended March 31, 2011 and 2010, respectively. Additionally, gas storage service accounted for 3 percent and 4 percent of operating revenues for the three-months ended March 31, 2011 and 2010, respectively.

     Operating expenses increased $2.9 million, or 5 percent, due primarily to i) higher property taxes of $1.0 million primarily attributed to adjustments of $0.6 million reflecting higher than anticipated property tax settlements, ii) higher allocated overhead from affiliates of $0.8 million, and iii) higher labor of $0.7 million.

CAPITAL EXPENDITURES

     Our property, plant and equipment additions were $13.8 million and $10.4 million for the three months ended March 31, 2011 and 2010, respectively. Our capital expenditures estimate for 2011 is discussed in our 2010 Annual Report on Form 10-K. That estimate includes the following new capital projects proposed by us:

North and South Seattle Lateral Delivery Expansions

     We have executed agreements with Puget Sound Energy to expand the North and South Seattle laterals and provide additional lateral capacity of approximately 84 MDth per day and 73 MDth per day, respectively. We estimate the expansion of the two laterals to cost between $28 million and $30 million. Both projects are currently targeted for service in fall 2012.

Item 4. Controls and Procedures

     Our management, including our Senior Vice President and our Vice President and Treasurer, 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 controls 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 Northwest 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 Senior Vice President and our Vice President and Treasurer. Based upon that evaluation, our Senior Vice President and our Vice President and Treasurer concluded that these Disclosure Controls are effective at a reasonable assurance level.

First-Quarter 2011 Changes in Internal Controls

     There have been no changes during the first quarter of 2011 that have materially affected, or are reasonably likely to materially affect, our Internal Controls.

PART II. OTHER INFORMATION

Item 1. LEGAL PROCEEDINGS.
		The information called for by this item is provided in Note 2. Contingent Liabilities and Commitments, included in the Notes to Financial Statements included under Part1, Item 1. Financial Statements of this Form 10-Q, which information is incorporated by reference.

Item 1A. RISK FACTORS.
		Part I, Item 1A. Risk Factors in our Annual Report on Form 10-K for the year ended December 31, 2010, includes certain risk factors that could materially affect our business, financial condition or future results. Those Risk Factors have not materially changed, except as set forth below:
		Our costs of testing, maintaining or repairing our facilities may exceed our expectations, and the FERC or competition in our markets may not allow us to recover such costs in the rates we charge for our services.
		We could experience unexpected leaks or ruptures on our gas pipeline system, or be required by regulatory authorities to test or undertake modifications to our systems that could result in a material adverse impact on our business, financial condition, and results of operations if the cost of testing, maintaining, or repairing our facilities exceed current expectations and the FERC or competition in our markets do not allow us to recover such costs in the rates we charge for our service. For example, in response to a recent third party pipeline rupture, the United States Department of Transportation Pipeline and Hazardous Materials Safety Administration issued an advisory bulletin which, among other things, advises pipeline operators that if they are relying on design, construction, inspection, testing or other data to determine the pressures at which their pipelines should operate, the records of that data must be traceable, verifiable, and complete. Locating such records and, in the absence of any such records, verifying maximum pressures through physical testing or modifying or replacing facilities to meet the demands of such pressures, could significantly increase our costs.

Item 6. EXHIBITS.
		The following instruments are included as exhibits to this report.

Exhibit		Description
3(a)		Statement of Partnership Existence of Northwest Pipeline GP (Exhibit 3.1 to our report on Form 8-K, filed October 2, 2007) and incorporated herein by reference.
3(b)		Amended and Restated General Partnership Agreement of Northwest Pipeline GP (Exhibit 3.1 to our report on Form 8-K, filed January 30, 2008) and incorporated herein by reference.
31(a)*		Certification of Principal 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.
31(b)*		Certification of Principal 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.

Exhibit		Description
32(a)**		Certification of Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

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.

Date: May 5, 2011

EXHIBIT INDEX

Exhibit		Description
3(a)		Statement of Partnership Existence of Northwest Pipeline GP (Exhibit 3.1 to our report on Form 8-K, filed October 2, 2007) and incorporated herein by reference.
3(b)		Amended and Restated General Partnership Agreement of Northwest Pipeline GP (Exhibit 3.1 to our report on Form 8-K, filed January 30, 2008) and incorporated herein by reference.
31(a)*		Certification of Principal 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.
31(b)*		Certification of Principal 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(a)**		Certification of Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.