USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

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

Interpretation Response #PI-22-0010

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

Interpretation Response Details

Response Publish Date:

Company Name: Navajo Tribal Utility Authority

Individual Name: Mr. Antony M. Davison

Location State: AZ Country: US

View the Interpretation Document

Response text:

Mr. Antony M. Davison
Natural Gas ECO Manager
Navajo Tribal Utility Authority
P.O. BOX 170
FT. Defiance, AZ 86504

Dear Mr. Davison:

In a letter to the Pipeline and Hazardous Materials Safety Administration (PHMSA), dated April 5, 2022, you requested an interpretation of the Federal pipeline safety regulations in 49 Code of Federal Regulations (C.F.R.) Part 192 with respect to the § 192.1(a) scope applicability to your gas pipeline outside of the Navajo Nation borders in the state of New Mexico.

You stated that until recently all Navajo Tribal Utility Authority (NTUA) owned and operated natural gas pipelines have been confined within the Navajo Nation borders. You also stated that with a recent acquisition of a portion of a former Questar Southern Trails Pipeline, NTUA now owns and will soon operate approximately 30-miles of pipeline that is located outside of the Navajo Nation border.

You further stated that PHMSA issued an interpretation to CPN Pipeline Company dated February 5, 2007, which you believe may exclude NTUA from having to comply with the Federal pipeline safety regulations based on the § 192.3 definition of "Person."1 You asked if the previously issued interpretation is also applicable to NTUA's 30 miles of pipeline operated outside of the Navajo Nation borders so that the pipeline would not have to comply with Part 192.

PHMSA's written clarifications of the Federal pipeline safety regulations are provided 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 are not generally applicable, do not create legally-enforceable rights or obligations, and are provided to help the specific requestor understand how to comply with the regulations.

Having considered and analyzed your request, PHMSA has concluded that the Pipeline Safety Act (PSA) applies to NTUA's owned or operated facilities outside of the Navajo Nation borders. PHMSA's pipeline safety program is a broadly applicable federal law and nothing in the law or legislative history indicates that pipelines operated by tribes were intended to be excluded from the pipeline safety program. In addition, a tribal owner or tribal operator of a pipeline is subject to PHMSA's jurisdiction pursuant 49 U.S.C. § 60102(a)(2)(A), which broadly states that pipeline safety standards apply to "any or all of the owners or operators of pipeline facilities." To exclude tribal operators would frustrate the purpose of the PSA and Congressional intent for a nationally applicable federal safety program by allowing safety gaps that pose an unreasonable risk to persons, property, and the environment outside the reservation. This interpretation of the PSA is in line with other federal safety and environmental regulatory programs that apply to tribes, as well as the federal hazardous materials transportation laws under which PHMSA regulates hazardous materials.

In your case, NTUA would be operating the former Questar Southern Trails natural gas pipeline, which is outside of the Navajo Nation’s borders. Under these specific facts and applying the above analysis, NTUA, as owner and operator of the pipeline, must comply with the 49 CFR Part 192 regulations, pursuant to 49 U.S.C. § 60102(a)(2)(A) and 49 U.S.C. 60118(a).2

If we can be of further assistance, please contact Tewabe Asebe at 202-366-5523.


John A. Gale
Director, Office of Standards
and Rulemaking

1 See February 5, 2007, Letter to Scott Vickers from Florence L. Hamm, PI-07-015, available at: (hereafter "2007 interpretation").

2 With regard to the 2007 interpretation referenced in your request, that interpretation was issued to a pipeline company that was not a tribe and that asked several questions related to the location of its pipeline. The requester did not ask the question presented by NTUA, which is whether a tribe must comply with the PSA. It was unnecessary for PHMSA in 2007 to suggest a view on whether tribal operator are among the entities defined as a "person" under the PSA. Moreover, PHMSA believes the 2007 interpretation was incorrect to state that the PSA does not apply to tribally-operated facilities for the reasons stated above. In addition, depending on its structure, a tribal organization that owns or operates a pipeline may fall under the definition of "person" under 1 U.S.C. § 1 and 49 C.F.R. § 192.3 as a corporation, company, association, or other enumerated business entity. For these reasons, the discussion of tribal operators in the 2007 interpretation is retracted. PHMSA notes further that the agency has a long history of regulating tribally-owned and -operated pipelines and appreciates the cooperation of those operators in our shared goal of pipeline safety.

Regulation Sections

Section Subject
192.1 What is the scope of this part?