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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #PI-18-0001

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Washington UTC

Individual Name: Mr. Sean C. Mayo

Location State: WA Country: US

View the Interpretation Document

Response text:

Mr. Sean C. Mayo
Pipeline Safety Director
Washington Utilities and
Transportation Commission
1300 S. Evergreen Park Drive, SW
Olympia, WA 98504-7250

Dear Mr. Mayo:

In a December 8, 2017, letter to the Pipeline and Hazardous Materials Safety Administration (PHMSA), you requested an interpretation of 49 CFR Part 192. Specifically, you requested an interpretation for the definition of a transmission line under § 192.3.

You described the pipeline as a 76.53-mile-long intrastate transmission pipeline (Kettle Falls Pipeline) operated by Avista Utilities. The pipeline receives gas from a connection with an interstate transmission pipeline operated by Northwest Pipeline LLC (Williams) at approximately 5-miles north of Spokane, Washington and transports gas to north of Kettle Falls, Washington. You stated that other than the first 3.8 miles of the pipeline, the pipeline operates above 20 percent of specified minimum yield strength (SMYS) and has historically been classified as transmission pipeline by Avista.

You stated that the first 3.8 miles, where the pipeline connects to the Williams transmission line, operates at 19.65 percent SMYS. You asked whether the 3.8-mile pipeline should be regulated as a transmission line since it operates at 19.65 percent SMYS and is tied into and receives gas from an interstate transmission pipeline.

"Transmission line" is defined in § 192.3 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."

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.

Even though the first 3.8 miles of the pipeline operates below the 20 percent SMYS, the pipeline connects to transmission lines at both ends and, therefore, meets condition 1 of the definition of a transmission line.

A pipeline that meets any of the three conditions listed under the definition in § 192.3 is a transmission line in accordance with 49 CFR Part 192. Therefore, a pipeline that operates at a hoop stress of less than 20 percent of its specified minimum yield strength, but meets either condition one or three, meets the definition of a transmission line.

PHMSA agrees with Washington Utilities and Transportation Commission that the 76.53-mile-long pipeline, including the first 3.8 miles of the pipeline, is a transmission line. If we can be of further assistance, please contact Tewabe Asebe at 202-366-5523.


John A. Gale
Director, Office of Standards
and Rulemaking

Regulation Sections

Section Subject
192.3 Definitions