This message is to inform you of a modification to PHMSA’s position concerning gas transmission integrity management assessments required every seven years.
The Pipeline Safety Improvement Act of 2002 requires that gas transmission IM programs provide for an assessment of covered segments at least every 7 years. This requirement was incorporated in 49 CFR 192.939. During theearly workshops on implementing IM requirements, questions were asked concerning the scope of assessments required at 7-year intervals. PHMSA responded that the assessments needed to address all threats applicable to the covered segment. This answer was incorporated in a Frequently Asked Question (FAQ-133).
PHMSA has recently re-evaluated the answer to this question and has concluded that it was incorrect. Section 192.939 requires that reassessment intervals be established and specifies maximum reassessment intervals that can be as long as 20 years for low-pressure pipelines. The intervals defined per this requirement are those in which all applicable threats must be assessed, using ILI, pressure testing, direct assessment, or “other technology” (with notification). Section 192.939(a) also states, in part:
“If an operator establishes a reassessment interval that is greater than seven years, the operator must, within the seven-year period, conduct a confirmatory direct assessment on the covered segment, and then conduct the follow-up reassessment at the interval the operator has established.”
Confirmatory direct assessment (CDA) is capable of identifying corrosion (and must be used in conjunction with data integration to identify third-party damage), but it does not address other threats. Nevertheless, this is the specific method required by the rule for the 7-year “confirmatory” assessments required by the Act. PHMSA has therefore concluded that, in cases where the reassessment interval established by the operator per 192.939(a)or (b) is greater than 7 years, the interim confirmatory reassessment need not address all applicable threats, but rather can be performed using CDA. (Note that a CDA assessment would be required within 7 years and again within 14 years in cases where the established reassessment interval exceeds 14 years).
An operator always has the option of establishing its reassessment intervals to be less than or equal to seven years, in which case it need not perform assessments using CDA.
The response to FAQ-133 has been revised. FAQs 40, 42, 43, and 207, all of which refer to seven-year inspections in some way, have also been modified accordingly.