WESTERN MIDSTREAM PARTNERS, LP — Warning Letter

520095032W_warning letter_08212009_text.pdf, page 1Official PDFWARNING LETTER CERTIFIED MAIL - RETURN RECEIPT REQUESTED August 21, 2009 Mr. Danny Rea Vice President of Midstream Anadarko Petroleum Corporation 1201 Lake Robbin Dr. The Woodlands, TX 77380 CPF 5-2009-5032W Dear Mr. Rea: On June 29 – July 2, 2009, a representative of the Pipeline and Hazardous Materials Safety Administration (PHMSA), pursuant to Chapter 601 of 49 United States Code, inspected your Wamsutter Crude Oil Pipe Line near Wamsutter, Wyoming. As a result of the inspection, it appears that you have committed a probable violation of the Pipeline Safety Regulations, Title 49, Code of Federal Regulations. The item inspected and the probable violation is: 1. §195.402 Procedural manual for operations, maintenance, and emergencies. (a) General. Each operator shall prepare and follow for each pipeline system a manual of written procedures for conducting normal operations and maintenance activities and handling abnormal operations and emergencies. This manual shall be reviewed at intervals not exceeding 15 months, but at least once each calendar year, and appropriate changes made as necessary to insure that the manual is effective. This manual shall be prepared before initial operations of a pipeline commence, and appropriate parts shall be kept at locations where operations and maintenance activities are conducted.#

520095032W_warning letter_08212009_text.pdf, page 2Per §195.402(a), the operator must conduct a review and update their Operations and Maintenance (O&M) manual at least once each calendar year and at intervals not exceeding 15 months. During the inspection, Anadarko Petroleum Corporation did not have records to indicate that their Operations and Maintenance manual was reviewed during the 2008 calendar year. 2006 O&M Manual Review 195.402(a) 2007 O&M Manual Review 195.402(a) 2008 O&M Manual Review Due Date (15 months) 2009 O&M Manual Review 195.402(a) 3-13-2006 January, 2007 3-02-2008 But not reviewed 5-1-2009 The exact day of the 2007 O&M review was not noted; therefore, the 15-month interval must default to January 2, 2007 and the due date for the 2008 O&M review should have been March 2, 2008. 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 Anadarko Petroleum 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 5-2009-5032W. 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 B. Brown (#123989) 2#