City of Susanville — Pipeline Safety Interpretation

Page 1U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration MAR 12 Z015 1200 New Jersey Ave, S.E. Washington, D.C. 20590 Mr. Craig Platt Public Works Director City of Susanville 66 North Lassen Street Susanville, CA 9613 0-3 904 Dear Mr. Platt: In a letter to the Pipeline and Hazardous Materials Safety Administration (PHMSA) dated October 23, 2013, you requested an interpretation concerning the applicability ofthe Federal pipeline safety regulations to a natural gas pipeline operated by the City of Susanville (City). Your letter essentially asked whether PHMSA considers the City's 6-inch, 10. 75-mile-long pipeline to be a transmission line or a distribution line. You stated that the City takes delivery of natural gas from Tuscarora Gas Transmission Company at a custody transfer meter station located approximately 10.75 miles north of Susanville. At this location, the City district regulator station reduces the line pressure down to 350 psig to feed the Susanville 6-inch pipeline. From the Tuscarora custody transfer meter, the pipeline travels approximately 3 miles to a pressure regulator station where the gas pressure is reduced from 350 psig to 90 psig for a branch running to a state correctional facility and to 60 psig for another branch running to a cogeneration power plant. From the pressure regulator station controlling delivery pressure to the correctional facility and the power plant, the pipeline extends an additional 7.75 miles to the City of Susanville gate station where gas pressure is further reduced from 350 psig to 50 psig to feed the City's PE distribution piping system and all of this piping transports odorized gas. A pipeline is classified as a "transmission line" if it meets any one of the three conditions in the definition of "transmission line" at § 192.3. Section 192.3 defines a gas "Transmission line" as: [A] pipeline, other than a gathering line, that: ( 1) transports gas from a gathering line or storage facility to a distribution center, storage facility, or large volume customer that is not down-stream from a distribution center; (2) operates at a hoop stress of 20 percent or more of SMYS; or (3) transports gas within a storage field. The Pipeline and Hazardous Materials Safety Administration, Office of Pipeline Safety provides written clarifications of the Regulations ( 49 CFR Parts 190-199) in the form of interpretation letters. These letters reflect the agency's current application of the regulations to the specific facts presented by the person requesting the clarification. Interpretations do not create legally-enforceable rights or obligations and are provided to help the public understand how to comply with the regulations.#

Page 22 NOTE: A large volume customer may receive similar volumes of gas as a distribution center, and includes factories, power plants, and institutional users of gas. The City may be currently operating the line at 350 psig, but it has an established Maximum Allowable Operating Pressure (MAOP) of 1000 psig. This MAOP was verified by Dan Newton, Interim Public Works Director/City Engineer for the City of Susanville, in an email to Mr. Jason Dunphy ofPHMSA's Western Region Office dated June 9, 2014. Under Part 192 regulations, the MAOP is used to calculate the percentage of Specified Minimum Yield Strength (SMYS) at which the pipeline is allowed to operate. Based on the information you provided, the pipeline is allowed to operate at 36 percent of SMYS, which exceeds 20 percent of SMYS. Therefore, the City of Susanville pipeline appears to be a transmission pipeline per the definition of "transmission line" at § 192.3. I hope this information is helpful. Ifwe can be of further assistance, please contact Tewabe Asebe, Transportation Specialist, Standards and Rulemaking Division, by phone at (202) 366-5523 or by email at tewabe.asebe@dot.gov. Sincerely, A~. t'to ~ , ~ ivrt'::/:i Deputy Associate Administrator for Policy and Programs The Pipeline and Hazardous Materials Safety Administration, Office of Pipeline Safety provides written clarifications of the Regulations ( 49 CFR Parts 190-199) in the form of interpretation letters. These letters reflect the agency's current application of the regulations to the specific facts presented by the person requesting the clarification. Interpretations do not create legally-enforceable rights or obligations and are provided to help the public understand how to comply with the regulations.#

Page 3City of Susanville (530) 257-1000 • 66 North Lassen Street • Susanville, CA 96130-3904 October 23, 2013 Jeffrey D. Wiese Associate Administrator Office ofPipeline Safety Pipeline and Hazardous Materials Administration U.S. Department of Transportation 1200 New Jersey Avenue, SE Washington, D.C. 20590-0001 Otl S 0 2013 RE: Interpretation of Transmission Lines Dear Mr. Wiese: The City of Susanville (located in Northeast California) operates a municipal natural gas distribution system, Operator ID No. 31599. This natural gas distribution system began operation on September 13, 2001. The Susanville natural gas system is currently serving 3,000 customers including a cogeneration power plant and a State of California correctional facility. Pursuant to discussions in the matter of natural gas transmission facilities vs. natural gas . . . distribution facilities with the PHMSA Western Region office, the City of Susanville respectfully requests a formal interpretation of transmission line as related to our natural gas system. The City of Susanville takes delivery of natural gas from Tuscarora Gas Transmission Company at a custody transfer meter station located approximately 10.75 miles north of Susanville. At this location, the City district ·regulator· station reduces the Tuscarora line pressure down to 350 psig to feed the Susanville 6-inch coated steel distribution feeder mainline. From the Tuscarora custody transfer meter and the City of Susanville district regulator station the City 6-inch high pressure mainline travels approximately 3 miles to a branch connection serving a State of California correctional facility and a cogeneration power plant, where gas pressure is further regulated from the 350 psig mainline pressure down to 90 psig and 60 psig respectively to serve these customers. At the furthest point of the 6-inch steel feeder mainline, approximately 10.75 miles downstream of the custody transfer station gas pressure, is regulated from 350 psig down to 50 psig at .the City of Susanville gate station feeding the City's PE distribution piping system serving local residential and small commercial customers. ' . '' ' Rod E. DeBoer Mayor Brian R. Wilson Mayor pro tern Coundlmembers: Lino P. Callegari Cheryl L. McDonald Nicholas McBride www. cit yOf susan vi 11 e ~or~#

Page 4The City of Susanville 6-inch high pressure steel feeder mainline operates at 350 psig,. approximately 12.6% of SMYS. It is our understanding, based on previous PHMSA interpretation that a distribution center commonly refers to that point where gas enters piping primarily to deliver gas to customers who purchase it for consumption as opposed to customers who purchase gas for resale. All of the gas distributed through the City of Susanville system is delivered to customers who purchase it for their own consumption, including the correctional facility and the cogeneration power plant. We believe that the distribution center can typically be represented by the point of transfer between the interstate pipeline, Tuscarora Gas Transmission Company and the City of Susanville. The City of Susanville does not transport gas directly from a gathering line or storage facility and does not transport gas within a storage field. We await your interpretation in this matter. Should you have any questions please do not hesitate to contact me at (530) 257-1041 or by e-mail at cplatt@cityofsusanville.org. Sincerely Craig Platt Public Works Director City of Susanville Cc: Christopher Hoidal Director Western Region Pipeline & Hazardous Materials Administration 12300 W. Dakota Avenue, Suite 100 ·Lakewood, CO 80228#