NORTHWEST PIPELINE LLC — Warning Letter

520091008W_warning letter_11232009_text.pdf, page 1Official PDFWARNING LETTER CERTIFIED MAIL - RETURN RECEIPT REQUESTED November 23, 2009 Mr. Larry Hjalmerson President Northwest Pipeline Corporation (WGP) 2800 Post Oak Blvd., Mail Stop 21 Houston, TX 77056 CPF 5-2009-1008W Dear Mr. Hjalmerson: On July 13, 2009, a representative of the Pipeline and Hazardous Materials Safety Administration (PHMSA), pursuant to Chapter 601 of 49 United States Code, inspected your Kemmerer District gas pipeline system in Kemmerer, Wyoming. As a result of the inspection, it appears that Northwest Pipeline Corporation (WGP) have committed a probable violation of the Pipeline Safety Regulations, Title 49, Code of Federal Regulations. The items inspected and the probable violations are: 1. §192.479 Atmospheric corrosion control; General. (a) Each operator must clean and coat each pipeline or portion of pipeline that is exposed to the atmosphere, except pipelines under paragraph (c) of this section. (b) Coating material must be suitable for the prevention of atmospheric corrosion. (c) Except portions of pipelines in offshore splash zones or soil-to-air interfaces, the operator need not protect from atmospheric corrosion any pipeline for which the operator demonstrates by test, investigation, or experience appropriate to the environment of the pipeline that corrosion will-#

520091008W_warning letter_11232009_text.pdf, page 2(1) Only be a light surface oxide; or (2) Not affect the safe operation of the pipeline before the next scheduled inspection. The coating was degraded and the pipe was exposed near the air-to-soil interface in the Green River Compressor Station yard on the Loop line riser, suction-side; and at the Crossover-16 riser. Under 49 United States Code, § 60122, you are subject to a civil penalty not to exceed $100,000 for each violation for each day the violation persists up to a maximum of $1,000,000 for any related series of violations. We have reviewed the circumstances and supporting documents involved in this case, and have decided not to conduct additional enforcement action or penalty assessment proceedings at this time. We advise you to correct the item(s) identified in this letter. Failure to do so will result in Northwest Pipeline Corporation being subject to additional enforcement action. No reply to this letter is required. If you choose to reply, in your correspondence please refer to CPF 5-2009-1008W. Be advised that all material you submit in response to this enforcement action is subject to being made publicly available. If you believe that any portion of your responsive material qualifies for confidential treatment under 5 U.S.C. 552(b), along with the complete original document you must provide a second copy of the document with the portions you believe qualify for confidential treatment redacted and an explanation of why you believe the redacted information qualifies for confidential treatment under 5 U.S.C. 552(b). Sincerely, Chris Hoidal Director, Western Region Pipeline and Hazardous Materials Safety Administration cc: PHP-60 Compliance Registry PHP-500 C. Allen (#123981) 2#