NTSB questions PG&E decisions on shutoff valves in San Bruno blast 

The raging gas fire that completely leveled a San Bruno neighborhood after a pipeline explosion in September could have been controlled sooner if automatic shutoff valves had been installed, it was revealed at a federal hearing Tuesday in Washington, D.C.

It was just one of the several questionable decisions, flaws and mishaps highlighted during the first of a three-day hearing by the National Transportation Safety Board into the causes of the blast and response of Pacific Gas and Electric, which oversaw the natural gas pipeline that exploded beneath the streets of San Bruno on Sept. 9.

PG&E officials admitted they could have shut down the flow of gas within 15 minutes if new valve technology had been installed. Instead, nearly 40 homes were destroyed, dozens more were damaged and eight people died as mile-high flames fed by the continuous gas flow consumed a neighborhood.

Moreover, it was revealed that PG&E officials dismissed the findings of a 1999 Transportation Department study that highlighted the dangers of not being able to automatically or remotely close valves.

During Tuesday’s hearing, PG&E employees were grilled on a 2006 memo that failed to acknowledge the 1999 study and downplayed the significance of installing the technology that would reduce the time it took to shut valves.

PG&E senior gas consulting engineer Chih-Hung Lee, who wrote the 2006 memo, maintained that the majority of damage in pipeline explosions occurs at the moment of the rupture and therefore the newer valves would do little to protect lives or homes.

When pressed about the omission of the Department of Transportation reports showing value in automated systems, Lee dodged questions and at some points simply became silent.

“I believe that the policy had been reviewed, analyzed and the conclusions were reasonable,” PG&E senior Vice President Edward Salas said, breaking the silence. PG&E has raised concerns about the dangers of automatic shutoff valves because they can result in low pipeline gas pressure that also creates hazards. However, since the disaster, the company has begun a pilot project to install a dozen of the automatic valves.

A number of other flaws were highlighted, including the lack of coordination in responding to the explosion.  

It took control room employees about 15 minutes to figure out what happened. The PG&E dispatch center sent an off-duty employee to investigate the explosion, but he was not qualified to operate the manual valves that were fueling fire.

Ultimately, it took 30 minutes to dispatch a qualified crew and 90 minutes for that crew to shut the valves, according to Keith Slibasager, PG&E’s manager of gas system operations.  In that time, 35 million cubic feet of gas was released, fueling death and destruction. A coroner’s report indicated that at least five people died while trying to flee the fires.

The hearing also focused on PG&E’s erroneous listing of the San Bruno pipeline as a “seamless” line, considered stronger than pipelines that have been welded together. It was discovered after the accident that welded pipe was used in San Bruno and that the welds were inferior.

PG&E said in other documents released by NTSB that its personnel improperly relied on records from the utility’s accounting department to determine the type of pipeline, rather than engineering documents that showed the correct type.


Disaster and recovery

In six months, San Bruno has gone from catastrophe to rebuilding

Sept. 9, 2010 – A 30-inch natural gas transmission line ruptures in the Glenview neighborhood of San Bruno. Nearly 40 homes are destroyed.

Sept. 12 – San Bruno residents whose homes were cleared by emergency responders are allowed to return home. California Public Utilities Commission directs PG&E to reassess its pipelines.

Sept. 13 – PG&E announces $100 “Rebuild San Bruno” fund for the city and residents in the affected area. CPUC orders PG&E to reduce pressure on Peninsula pipelines.

Sept. 17 – The first lawsuit related to the disaster is filed in San Mateo County Superior Court.

Sept. 27 – Jim Franco, 58, dies, marking the disaster’s eighth fatality.

Oct. 13 – National Transportation Safety Board releases preliminary report on its investigation, revealing a pressure increase in the line came just before the rupture.

Dec. 14 – NTSB releases update on investigation, revealing that PG&E’s records indicated the pipe that ruptured was seamless when in fact it had several welds.

Jan. 3 – NTSB issues six urgent recommendations calling on pipeline operators to recheck their records for accuracy.

Jan. 7 – Owners of 1710 Claremont Dr. become the first to submit rebuilding plans under the city’s expedited permitting process. Plans were approved Jan. 27.

Jan. 10 – San Bruno City Council approves distribution of $395,000 in donations to victims of the explosion.

Jan. 21 – NTSB releases metallurgical reports indicating faulty welds on the section of pipeline that ruptured.

Feb. 2 – CPUC orders PG&E to reduce pressure on additional transmission lines due to deficiencies in PG&E’s records.

Feb. 15 – The Magoolaghan family becomes the second to win approval of rebuilding plans, for their home at 1611 Claremont Dr.

Washington Examiner reporter Caitlin Byrnes contributed to this report.

About The Author

Staff Report

Staff Report

A daily newspaper covering San Francisco, San Mateo County and serving Alameda, Marin and Santa Clara counties.
Pin It

More by Staff Report

Latest in Peninsula

© 2018 The San Francisco Examiner

Website powered by Foundation