PHMSA Advisory Bulletin ADB -11-01: MAOP / MOP and IMP

Editor’s Note: Due to the importance of this advisory bulletin, we felt it was worth repeating one more time.

On January 3, 2011, The National Transportation Safety Board (NTSB) issued recommendations to PHMSA, CPUC, and PG&E related to the San Bruno pipeline incident (see related article in this month’s newsletter). NTSB’s preliminary findings indicate that the pipeline operator did not have an accurate basis for the MAOP calculation.

PHMSA issued ADB-11-01 on January 4, 2011 entitled: Pipeline Safety: Establishing Maximum Allowable Operating Pressure or Maximum Operating Pressure Using Record Evidence, and Integrity Management Risk Identification, Assessment, Prevention, and Mitigation. The ADB states that operators “must assure that the records used are reliable” when calculating MOP / MAOP, and that “these records shall be traceable, verifiable, and complete”. It further states that “If such a document and records search, review, and verification cannot be satisfactorily completed, the operator cannot rely on this method for calculating MAOP or MOP.”

It further states: “Any operator of a hazardous liquid or gas transmission pipeline that is not fully cognizant of the location, pipe material and seam type, coating, cathodic protection history, repair history, previous pressure testing, or operational pressure history, and other assessment information, incident data, soil type and environment, operational history, or other key risk factors of a pipeline operating at or above 30% SMYS should 1) institute an aggressive program as soon as possible to obtain this information, 2) assess the risks, and 3) take the proper mitigative measures based upon the operator’s IM program risk findings. In addition, if these operators do not have verified information on key risk factors, an immediate and interim mitigation measure that should be strongly considered is a pressure reduction to 80 percent of the operating pressure for the previous month, hydro testing the pipeline or creating a remediation program to identify threat risks.”

This is a very significant advisory, and indicates a policy shift within PHMSA that could have profound implications for some pipeline operators. For example, operators that have relied upon “default” values for key risk factors in the integrity management program or when calculating their MOP / MAOP (in the absence of data about particular line segments) may now be required to determine the actual values for each factor; and, they may be expected to take interim pressure reductions until that data is obtained. This could require a significant data-gathering and analysis effort – especially for older pipeline systems.

The advisory states that “Future PHMSA inspections will place emphasis on the areas noted in this Advisory Bulletin.” The advisory also mentions that PHMSA and its state partners intend to sponsor a public workshop on these issues, but the date for this workshop has not yet been determined. We will inform you of the details once they are established.

For a copy of ADB-11-01, or for help in addressing these issues, contact Jessica Roger.