# Montana-Dakota Utilities Company — Pipeline Safety Interpretation

- **operation:** document
- **citation:** PI-03-0104
- **title:** Montana-Dakota Utilities Company — Pipeline Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2003-06-11
- **effective on:** Not available
- **summary:** PI-03-0104 response to Montana-Dakota Utilities Company concerning 192.721.
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-03-0104.json
- **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-03-0104.md
- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-03-0104
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/Pipeline/2003/g03-06-11_Lee_192.721-msfx.pdf
**body:**

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PI-03-0104
U.S. Department of Transportation
Research and Special Programs Administration
400 Seventh St., S.W.
Washington, D.C. 20590
June 11, 2003
Mr. Douglas M. Lee, P.E.
Senior staff Engineer
Montana-Dakota Utilities Company
400 North Fourth Street
Bismarck, ND 58501
Dear Mr. Lee:
This is in response to your letter of May 14, 2003, which asks for an interpretation of 49 CFR 192.721 as
it applies to the frequency of patrolling of gas distribution mains that are attached to an apartment building.
Section 192.721(a), Distribution Systems: Patrolling, states that the frequency of patrolling of gas
mains is to be determined by the gas distribution pipeline operator based on an evaluation of conditions that
could lead to failure or leakage, and the possible hazards to the public. Section 192.721(b) specifies patrol
frequencies for "mains in places or on structures where anticipated physical movement or external loading
could cause failure or leakage . . ."
The question is whether a gas main attached to a building is subject to "anticipated physical movement
or external loading" that could cause system failure or leakage and require specific patrolling frequencies as
specified in § 192.721(b). Generally, pipelines installed in or on structures, including buildings and bridges, are
not subject to movement or loadings that could cause failure if the pipeline is designed, constructed, and
maintained in accordance with 49 CFR Part 192.
Moreover, under § 192.721(a) the gas distribution pipeline company is responsible for making a
determination of patrol frequency based on its evaluation of the conditions which could cause failure and
leakage, subject to confirmation during inspections by State or Federal pipeline safety personnel.
If you have any further questions about the pipeline safety regulations, please contact me at (202)
366-4565.
Sincerely,
Richard D. Huriaux, P.E.
Manager, Regulations
Office of Pipeline Safety

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Montana-Dakota Utilities Co.
400 North Fourth Street
Bismarck, ND 58501
May 14, 2003
Richard Huriaux
Office of Pipeline Safety, Research and Special
Programs Administration, U.S. Department of Transportation
400 Seventh Street, S.W., Rm. 7128
Washington D.C. 20590-0001
Re: CFR 19 Part 192.721 (b)
Dear Mr. Huriaux:
With respect to the above referenced regulation, I have found a disparity in how many operators
interpret this regulation and look forward to resolution through your interpretation. The regulation
clearly states that this additional patrolling is necessary for "Mains in places or on structures where
anticipated physical movement or external loading could cause failure or leakage must be patrolled
-". Based on this verbiage combined with operational experience of over 75 years, one could easily
attest that pipelines properly supported on structures such as bridges or buildings are not subject to
movement that could cause failure or leakage. Just as stream crossings can wash out, a bridge could
fail due to flooding conditions and a prudent operator will monitor all areas subject to movement
following any natural or man-made activity that could affect the integrity of its system.
Attached are photographs of a "main" attached to an apartment complex. Based on the verbiage of
192.721 (b), it appears that the operator is granted the discretion to either include or exclude this
piping from quarterly or semi-annual line patrols. Can you either confirm this interpretation or provide
additional insight to the position held by the Office of Pipeline Safety?
Thank you for your response in this matter.
Sincerely,
Douglas Lee, P.E.
Senior Staff Engineer
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