Updated Aug. 30, 2011 at 7:22 p.m.
WASHINGTON — Federal investigators blamed more than five decades of inadequate safety practices by Pacific Gas and Electric Company for last year's deadly pipeline explosion in San Bruno — and expressed scorn for and frustration with the utility's inability to provide key pipeline documents or learn from its past mistakes.
The company installed a “substandard and poorly welded pipe section” in 1956 and then failed to detect a “visible seam weld flaw” that grew over time until “poorly planned” electrical work on Sept. 9, 2010 triggered a power outage that caused pipeline pressure to spike, prompting the devastating rupture, the National Transportation Safety Board ruled unanimously Tuesday.
Ill-considered state and federal pipeline safety rules and complacent state utility regulators also contributed to the disaster, the board found, and PG&E's botched response to the explosion made matters worse.
The rulings were based on an intensive 51-week inquiry involving 40 investigators who reviewed thousands of documents and interviewed scores of regulators and current and past company employees. Those investigators, however, were unable to secure documents from PG&E that would have indicated where and how the shoddy pipeline, which did not meet present-day or 1950s safety standards, was constructed.
Safety board investigators painted a clear picture of the disaster during a public hearing Tuesday, describing in precise and shocking detail the many failings by PG&E that eventually triggered the disaster, which killed eight people, injured 58 others and left many more homeless.
Faulty welds on the pipeline's internal seams, which eventually blew open, were visible to the naked eye — even after the pipe had been mangled, thrown 100 feet by the force of the explosion and engulfed in flames. Yet they remained undetected for more than five decades. A PG&E worker told NTSB investigators that he climbed through the pipe after it was installed in 1956 — but that he was not qualified to inspect it for weaknesses.
"His job was to pick up debris," lead NTSB investigator Ravi Chhatre said during Tuesday’s hearing. "He was crawling about in the dark. He couldn't see any seam welds."
For decades afterwards, PG&E failed to do inspections, which NTSB investigators said would certainly have revealed the pipeline's weaknesses.
NTSB Chairwoman Deborah Hersman said during the hearing that the tragedy “was compounded over the years by a litany of failures — including poor recordkeeping, inadequate inspection programs and an integrity management program without integrity.”
"It was not a question of if this pipeline would burst, it was a question of when,” she said.
After the pipeline exploded, PG&E’s failure to prepare for such a disaster, coupled with a lack of remote-controlled or automatic shutoff valves, worsened the severity of the accident, the NTSB board members ruled.
Throughout Tuesday's hearing, the safety board criticized PG&E for failing to learn from past mistakes, such as a 2008 pipeline explosion in Rancho Cordova that killed one person. An NTSB investigation into that accident also found that the pipeline and PG&E's emergency response were inadequate.
Since the San Bruno explosion, the company has replaced two of its most senior officials, reduced the operating pressure along many of its aging pipelines and proposed a $2.2 billion safety overhaul that it says should be funded largely by its customers. It faces nearly 100 lawsuits filed by hundreds of people affected by the explosion. State regulators say they could levee significant fines in December related to the blast.
"We at PG&E will take to heart the NTSB’s findings from its thorough and independent investigation into the tragic San Bruno accident," company President Christopher Johns said in a statement following Tuesday's hearing. "Because we firmly share the Board’s commitment to seeing that such a terrible accident never happens again, we are grateful for its meticulous review of evidence, finding of facts and thoughtful recommendations."
The board also heaped criticism on PG&E’s state and federal regulators, the California Public Utilities Commission and the U.S. Pipeline and Hazardous Materials Safety Administration.
Those agencies’ decisions to exempt aging pipelines from inspections that are required of newer pipes contributed to the accident, the NTSB determined. The CPUC’s failure to detect PG&E’s inadequacies was also found to have contributed to the accident.
"Ronald Reagan famously said, 'Trust, but verify,'” Hersman said in her closing remarks Tuesday. “For government to do its job — safeguard the public — it cannot trust alone. It must verify through effective oversight. And as we saw in San Bruno, when the approach to safety is lax, the consequences can be deadly.”
The safety board issued 29 new safety recommendations to regulators, other agencies, PG&E and the natural gas industry to help prevent such a tragedy from recurring. Those recommendations included audits, system upgrades and mandatory installation of automatic or remote-controlled shutoff valves. No other recent accident has prompted so many recommendations, board member Robert Sumwalt said.
California has already begun implementing new rules based on preliminary recommendations from the NTSB. State and federal lawmakers, meanwhile, are working on various pieces of legislation that could help protect the public and the environment from ruptured pipelines, which have become more frequent in recent years.
In a statement Tuesday, the CPUC's executive director, Paul Clanon, said that the commission welcomed the NTSB's recommendations and would "ensure that PG&E corrects any deficiencies that led to the rupture."
The CPUC has already ordered utility companies to test older pipes and is evaluating plans to install automatic valves, Clanon said. It will now assess whether it needs to adopt new rules to enforce the NTSB's recommendations. And, by the end of the year, the agency expects to give its staff the ability to "fine natural gas operators immediately if a violation is found," Clanon said.
Besides laying blame, the board also absolved the city of San Bruno of wrongdoing. In federal filings, PG&E had alleged that a 2008 sewer replacement project had weakened the pipeline and contributed to the disaster.
But NTSB investigator Donald Kramer on Tuesday stated categorically that the sewer project played no role in the accident.
“We've looked at this sewer replacement project in great detail, and we cannot make it work — we cannot find a scenario in which it would have damaged the pipe,” Kramer said.
San Bruno Mayor Jim Ruane said he was not surprised by that finding.
“We felt that all along — just to confirm that, we brought on an expert,” Ruane said in an interview after the hearing. "He said, ‘There’s no way this could have impacted anything.’”
Since the accident, six homeowners have begun rebuilding their homes, and another has received the necessary building permits.
Ruane said while “higher-ups” and “legislators” respond to Tuesday's ruling, the city will continue to focus on recovery.
“We have to take care of our citizens, our residents, our friends and our families,” Ruane said. “We’re still in the rebuilding, and that’s what we’re going to do — we’re going to take care of our people.”