NTSB hearing focuses on remote shut-off valves

The shell of a truck sits in front of a burned home near the epicenter of the gas line explosion that devastated a neighborhood near San Francisco International Airport on Sept. 24, 2010 in San Bruno, Calif.
The shell of a truck sits in front of a burned home near the epicenter of the gas line explosion that devastated a neighborhood near San Francisco International Airport on Sept. 24, 2010 in San Bruno, Calif. Justin Sullivan/Getty Images

The National Transportation Safety Board began on Tuesday three days of hearings in Washington, DC to examine causes of last fall’s pipeline rupture in San Bruno. The natural gas explosion and fire killed eight people and destroyed dozens of homes.

National Transportation Safety Board Chair Deborah Hersman set the scene in San Bruno, a city south of San Francisco near the SFO airport: "On Sept. 9, 2010," she said, "a little after 6 p.m., as commuters were arriving home from work and families were sitting down at the dinner table, a 30-inch-diameter natural gas pipeline ruptured."

The explosion carved out a giant crater, and blew a 28-foot chunk of pipe a football field away. NTSB investigator Ravi Chhatre said a pair of off-duty employees reported the fire to Pacific Gas and Electric.

"The dispatch center dispatched an on-duty employee to investigate the reported explosion," said Chhatre.

But that employee wasn’t qualified to shut off the pipeline. It took PG&E an hour and a half to stop the flow of natural gas that was fueling the fire.

Much of the hearing focused on why the pipeline didn’t have a remote shut-off valve. NTSB investigator Robert Trainor pressed PG&E consulting engineer Chih-Hung Lee about a policy memo he wrote five years ago. He asked Lee to read from a federal report that concludes the longer that natural gas flows, the more potential there is for damage.

"The degree of disruption in the heavily populated or commercial area would be in direct proportion to the duration of the fire," Lee read.

Trainer said he wanted to contrast that conclusion with Lee's memo which states, "the duration of the flame has little or nothing to do with human safety or property damage."

Lee said he based his memo on pipeline industry research that said most of the damage occurs in the first 30 seconds after a gas line rupture. But the San Bruno blast touched off a fire that firefighters couldn’t stop until the gas was shut off manually 90 minutes after the blast. PG&E officials testified that had there been a remote shut-off valve in place, the gas could have been turned off in 20 minutes.

Democratic Congresswoman Jackie Speier has introduced a bill that requires pipeline operators to install automatic or remote shut-off valves. Speier’s district includes San Bruno.

"I am frankly sick and tired of a scenario on Capitol Hill," she said, "where we hold hearings over and over again and then don’t do anything. I want to see something done this time."

The House hasn’t yet scheduled a committee hearing for Speier’s bill.

On the second day of the NTSB’s San Bruno hearings, the board will hear from San Bruno’s fire chief and from members of the California Public Utilities Commission.

Kitty Felde is KPCC's Washington, DC correspondent. You can follow her blog posts throughout the NTSB hearings.

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