Natural Gas Transmission Pipeline Leaks & Repair Criteria

Smart Pig’s Question of the Week – 

A Texas farmer recently contacted us to ask how long could an operator allow a leak from a natural gas transmission line to go without being repaired? He indicated that a leak – identifiable by the soil being sprayed up in the air above the line – had reportedly been visible in a neighboring field for some time, and there had been no apparent effort by the operator to repair it.

Leaving aside all of the reasonable, predictable questions about how that could happen or what an operator’s representative might have said when notified of the leak, here’s what the regulations say about leaks in gas transmission lines. As we suggested in our last post, the regulations vary depending on whether the leak is in a “high consequence area” (HCA) – generally an area of higher population. If you need the details on how gas transmission line operators identify HCAs, you can find them here.

This leak is nowhere near a high consequence area. Not even close. So the leak repair criteria in the gas integrity management rules that would apply in HCAs don’t apply. That means the repair falls under the general gas transmission repair regulations, found at 49 CFR § 192.711, seen in the box below.

 

§ 192.711 Transmission lines: General requirements for repair procedures.

(a)Temporary repairs.Each operator must take immediate temporary measures to protect the public whenever:
(1)A leak, imperfection, or damage that impairs its serviceability is found in a segment of steel transmission line operating at or above 40 percent of the SMYS; and
(2) It is not feasible to make a permanent repair at the time of discovery.
(b)Permanent repairs.An operator must make permanent repairs on its pipeline system according to the following:
(1) Non integrity management repairs: The operator must make permanent repairs as soon as feasible.
(2) Integrity management repairs: When an operator discovers a condition on a pipeline covered under Subpart O-Gas Transmission Pipeline Integrity Management, the operator must remediate the condition as prescribed by § 192.933(d).
(c) Welded patch.Except as provided in § 192.717(b)(3), no operator may use a welded patch as a means of repair.

 

To paraphrase, an operator must make immediate temporary repairs to protect the public, but only when lots of qualifiers apply to the situation:

1) the leak/imperfection/damage impairs the serviceability of a pipeline;

2) the line is operating at or above 40% SMYS (specified minimum yield strength, defined in 49 CFR § 192.4); and

3) it is not feasible to make a permanent repair at the time of discovery.

For permanent repairs, none of those qualifiers are necessary: for non-integrity management repairs, meaning like the line in question it is not in a high consequence area, the operator must make permanent repairs “as soon as feasible”. So that begs the question, what does “as soon as feasible” mean? It doesn’t say “immediately,” (presumably because they’ve already made immediate temporary repairs where there is risk to the line or to the public) but it also doesn’t say “as soon as practicable,” or “in the course of ordinary business.” To an ordinary reader, I think “as soon as feasible” would mean “as soon as you can, even if that’s sooner than you want to.”

Unfortunately, the answer could get a bit muddier (or at least more expensive to determine) if one were to look to the rules for repairs on pipes subject to integrity management rules for guidance in determining how soon is “as soon as feasible.” That’s because, as noted in the text box above, repairs on pipes in high consequence areas are required to follow the criteria in 49 CFR 192.933 (d) in remediating a “condition.”  If we assume that a leak qualifies as a “condition,” (and I would argue it does, since “condition” is used in §192.711 interchangeably with “leak, imperfection or damage”) then an operator needs to determine, within 180 days, whether it poses a potential threat to the integrity of the line. Assuming it does pose such a threat, then the operator has to “complete remediation of the condition” within the timeframes included in an industry standard incorporated by reference into the PHMSA regs, but unavailable to mere members of the public unless you either buy them at considerable expense, or trek to the bowels of the Department of Transportation office or the National Archives, both in Washington DC in order to see a copy of them. Once there, you will want to see the schedule in ASMA/ANSI B31.8S, Section 7, figure 4. Unfortunately, this little piggy has not purchased the appropriate set of industry standards, nor am I able to travel to either of these offices, so I am not able to tell you how a leak large enough to blow soil into the air might be classified for repair. The remainder of subsection (d) of the regulation is not of much assistance, either: it names specific types of anomalous conditions on a pipe and indicates whether they are “immediate repair conditions”, “180 day repair conditions”, or a “monitored condition”, which need not be repaired until it gets worse. Leaks are not included in any of those lists.

Bottom line: Leaks on gas transmission lines outside of HCAs need to be repaired as soon as feasible. Leaks inside HCAs: it depends – but only somebody with the industry standards can tell you exactly on what it depends. And I expect there will be continuing conversations about whether it’s okay to make people who live with the consequences of a law pay a private industry organization for a copy of a standard that has been incorporated into that law.

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