Website: https://solempipelinesafetyconsulting.com/
In 2022 – my last year with PHMSA – I inspected a midwestern natural gas transmission operator who was using personal air monitors to detect underground gas leaks. When I investigated further with my PHMSA Central Region colleagues, I learned that every year there are a few enforcement actions for operators using equipment not rated by the manufacturer for detecting underground leaks (like the personal air monitors in this case). I have copied below an excerpt from the enforcement letter for a different operator using the incorrect equipment for underground gas leak detection:
- § 192.706 Transmission lines: Leakage surveys.
Leakage surveys of a transmission line must be conducted at intervals not exceeding 15 months, but at least once each calendar year. However, in the case of a transmission line which transports gas in conformity with § 192.625 without an odor or odorant, leakage surveys using leak detector equipment must be conducted-
(a) In Class 3 locations, at intervals not exceeding 7 1/2 months, but at least twice each calendar year;
Texas Gas failed to conduct leakage surveys on Class 3 transmission lines that transported gas without an odor or odorant using leak detector equipment. During the inspection PHMSA observed Texas Gas personnel using improper leak detectors for leakage surveys. Per PHMSA’s request, Texas Gas subsequently provided records of five separate devices that were in use that were not designed for detecting leaks from underground pipe. From a review of manufacturer design specifications for these detectors, PHMSA found that these devices were designed for detection of leaks in above-ground pipe or for higher concentrations of gas to detect hazardous or explosive atmospheres to ensure personnel safety. Additionally, Texas Gas’ own personnel acknowledged that the instruments in use were not appropriate for leak detection on the right of way.
From 2017 to 2020 the following improper detectors were used: TIF 8800X, MSA Altair 4X, Gas Trac NGX-6, Sperian Multipro, and Leakator. These instruments were found to have been used in the following Texas Gas locations: Jeffersontown, Hardinsburg, Leesville, Dillsboro, Bowling Green, Calvert City, Petersburg, West Greenville, Hanson, Slaughters, Bastrop, Isola. Accordingly, the leakage surveys at these locations were inadequate and Texas Gas is therefore in violation of the regulation.
I recommend that all gas transmission operators and all gas distribution operators confirm with the manufacturer data provided with your leak detector that it is suitable for detecting underground gas leaks. For gas distribution operators, the code requirement for a suitable detection instrument is:
- 192.723 Distribution systems: Leakage surveys.
(a) Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section.
(b) The type and scope of the leakage control program must be determined by the nature of the operations and the local conditions, but it must meet the following minimum requirements:
(1) A leakage survey with leak detector equipment must be conducted in business districts, including tests of the atmosphere in gas, electric, telephone, sewer, and water system manholes, at cracks in pavement and sidewalks, and at other locations providing an opportunity for finding gas leaks, at intervals not exceeding 15 months, but at least once each calendar year.
(2) A leakage survey with leak detector equipment must be conducted outside business districts as frequently as necessary, but at least once every 5 calendar years at intervals not exceeding 63 months. However, for cathodically unprotected distribution lines subject to § 192.465(e) on which electrical surveys for corrosion are impractical, a leakage survey must be conducted at least once every 3 calendar years at intervals not exceeding 39 months.