NORTHWEST NATURAL GAS CO — Warning Letter

120190003W_Warning Letter_03042019_text.pdf, page 1Official PDFWARNING LETTER OVERNIGHT EXPRESS DELIVERY March 4, 2019 Mr. Jon Huddleston Vice President, Engineering and Utility Operations Northwest Natural Gas Co 220 N.W. Second Avenue Portland, OR 97209 CPF 1-2019-0003W Dear Mr. Huddleston: From October 30 through November 1, 2018, representatives of the Pipeline and Hazardous Materials Safety Administration (PHMSA) pursuant to Chapter 601 of 49 United States Code inspected Northwest Natural Gas Co’s (NWN) MIST Underground Natural Gas Storage Field (MIST UGS Field). The inspection was was conducted at the NWN offices in Portland, Oregon and the MIST UGS Field located 55 miles northwest of Portland in Columbia county, Oregon. As a result of the inspection, it is alleged that you have committed a probable violation of the Pipeline Safety Regulations, Title 49, Code of Federal Regulations (CFR). The items inspected and the probable violation(s) are: 1. § 192.12 (d) Underground natural gas storage facilities. (d) Each underground natural gas storage facility that uses a depleted hydrocarbon reservoir or an aquifer reservoir for gas storage, including those constructed not later than July 18, 2017 must meet the operations, maintenance, integrity demonstration and verification, monitoring, threat and hazard identification, assessment, remediation, site security, emergency response and preparedness, and recordkeeping requirements and recommendations of API RP 1171, sections 8, 9, 10, and 11 (incorporated by reference, see §192.7) by January 18, 2018. NWN failed to meet the applicable requirements and recommendations of API RP 1171, section 10. Specifically, NWN did not have permanent weatherproof signs installed at the MIST UGS#

120190003W_Warning Letter_03042019_text.pdf, page 2CPF 1-2019-0003W Field at each well site for identification purposes as required by API RP 1171, Section 10.4.1. API RP 1171, Section 10.4.1, Minimum Signage Information, states in part: Permanent weatherproof signage shall be installed at each well site for identification purposes. During the field inspection at the MIST UGS Field, PHMSA discovered that NWN did not have permanent weatherproof signs installed at the following well sites:  23adh-3  33ac-3  23ach-3  33-3  33d-3  44-3 No reply to this letter is required. 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). No reply to this letter is required. If you choose to reply, please submit all correspondence in this matter to Robert Burrough, Director, PHMSA Eastern Region, 840 Bear Tavern Road, Suite 300, West Trenton, NJ 08628. Please refer to CPF 1-2019-0003W on each document you submit, and whenever possible provide a signed PDF copy in electronic format. Smaller files may be emailed to robert.burrough@dot.gov. Larger files should be sent on a CD accompanied by the original paper copy to the Eastern Region Office. Sincerely, Robert Burrough Director, Eastern Region Pipeline and Hazardous Materials Safety Administration 120190003W_Warning Letter_03042019_text Page 2 of 2#