Updated June 8, 2011 at 8:56 p.m.
Federal safety officials learned just a few weeks ago that there had been a gas leak more than two decades earlier on the same pipeline that caused a deadly explosion and fire in San Bruno last fall.
Deborah Hersman, chairwoman of the National Transportation Safety Board, told reporters Wednesday that a leak occurred in 1988 on Line 132 just nine miles south of the site of the San Bruno disaster.
“We certainly would have expected that information earlier,” Hersman said. “What we’re concerned about is the process that prevented them from providing this to us sooner.”
Pacific Gas and Electric Company unearthed documentation of the leak as part of an ongoing review of records following the San Bruno explosion, according to a company spokesman.
"We thought this documentation might be relevant to the NTSB's investigation, so we provided it to them immediately as soon as we discovered it," spokesman Brian Swanson said.
The records show that PG&E found the flaw in 1988 as part of a routine annual inspection, he said. It was a small leak, characterized as a longitudinal well defect, he said. "That can refer to a wide range of things, including a small pinhole leak," Swanson said.
"Because we identified that leak on a gas transmission line, we took a conservative approach to the repair, and we cut out and replaced a 12-foot section of that line in 1988," he said.
It's up to the NTSB to determine whether the leak has any relevance to last fall's deadly explosion — but "there were no indications of a leak prior to the rupture in San Bruno," Swanson said.
As for why the company did not disclose the leak to authorities for 23 years, Swanson said: "We have acknowledged that our record-keeping practices are not where they should be," and the company is working to "bring our record-keeping practices up to industry-leading levels."
An administrative law judge on Wednesday granted PG&E extra time to provide the California Public Utilities Commission with records of welding flaws in its natural gas pipelines, the San Jose Mercury News reported.
Hersman discussed the 1988 leak at a press conference held in San Bruno Wednesday to announce new safety recommendations for PG&E and the federal Pipeline and Hazardous Materials Safety Administration.
San Bruno officials, families affected by the tragedy and Rep. Jackie Speier, a Democrat whose district includes San Bruno, joined Hersman in front of the gaping crater that remains as a reminder of the fireball that killed eight people and destroyed dozens of homes on Sept. 9, 2010.
The disaster was "a painful and deadly lesson for the country," Speier said. "I believe that a lot of entities were asleep at the switch."
After the pipeline burst, 16 minutes elapsed before PG&E technicians called 911, according to the NTSB. The safety board on Wednesday recommended that PG&E require its control-room operators to immediately call 911 if they suspect a pipeline rupture. It also recommended that PHMSA require pipeline operators to have such a policy.
Additionally, the NTSB recommended that the pipeline administration provide specific characteristics of pipes, such as diameter and operating pressure, to emergency responders in the communities where the transmission lines are located.
"We want to make sure this accident will never occur again in another community," Hersman said.
Swanson said PG&E has already adopted the recommendations.
"We’ve met with first responders throughout our service area and provided them with the critical information they need about our gas systems for their emergency response plans. And we’ll continue to work with them to identify the most efficient ways to give them immediate notice of any emergency involved in our system," he said.
An independent panel formed by the CPUC to review the San Bruno rupture will present its report at 9:30 a.m. Thursday to commissioners. The CPUC also plans to discuss on Thursday a proposal to require PG&E to pressure-test or replace all of its natural gas pipelines.