PG&E Grilled About Memo Discouraging Use of Automatic Shutoff Valves

PG&E’s policy to not install remote or automatic shutoff valves on its pipelines was based solely on input from other pipeline operators, despite a previous federal study that recommended the valves be installed on Line 132 and similar gas transmission lines, PG&E officials said today on the first day of the NTSB’s hearing on the Sept. 9 pipeline explosion.

The utility’s decision to delay installing on before the Crestmoor disaster relied on findings from a 2006 internal memo that claimed the valves had limitations in preventing significant damage if an explosion occurred.

It took a PG&E crew more than an hour and a half to shut off the pipe on Sept. 9 because the line had manual valves. By that time, the fire had already claimed the lives of several residents, dozens of others had been injured and more than 30 homes had been destroyed in the neighborhood.

The 2006 PG&E memo (see attached) became a point of contention throughout most of the morning.

In testifying before technical experts from the National Transportation Safety Board, Chin-hung Lee, the senior consulting gas engineer who wrote the 2006 memo, said the other pipeline industry studies concluded that most damage after a pipeline explosion happens within the first 30 seconds and that using automatic or remote shutoff valves in densely populated areas such as the Crestmoor neighborhood would have “little or no effect on increasing human safety or protecting properties” following an explosion. 

That conclusion was used by the utility in determining the operation of Line 132, despite a finding in a 1999 Department of Transportation study that said remote controlled valves were reliable.

Lee, however, couldn’t provide a conclusive answer about how the valves work, and he provided conflicting answers—often fumbling over his words—about how long it would take crews to shut down a pipe if remote or automatic shutoff valves were installed, showing the possible inconclusiveness of the industry studies that his memo relied upon.

Edward Salas, PG&E’s senior vice president of engineering and operations, chimed in to provide more explanation.

“In theory, if remote valves were close to the site, they would have worked,” Salas said. “It really depends on where the valves are in relation to the rupture site. We don’t have the analysis yet from the investigation to determine what the impact would have been.”

Following PG&E’s testimony, Congresswoman Jackie Speier, who was sitting in the audience during the hearing, said she found the utility’s stance on remote and automatic shutoff valves “preposterous.”

“It’s frightening to me to think that’s the kind of analysis that PG&E would engage in in making an assessment on safety because we all know the industry is always going to spin it slightly differently,” Speier said.