The NTSB blamed a series of missteps by PG&E for last year's San Bruno pipeline explosion that killed eight people and destroyed 38 homes.
The federal safety panel also warned there was no certainty that the problems that led to last year's accident don't exist elsewhere in the Bay Area or across the country.
"The aging pipelines, our oldest pipelines really are without a safety net,'' NTSB chairman Deborah Hersman said.
The National Transportation Safety Board (NTSB) held the hearing on its exhaustive investigation into the deadly pipeline explosion just one week ahead of the one year anniversary of the blast.
At the conclusion of the hearing the federal safety panel unanimously agreed that a series of actions by PG&E caused the explosion. They also agreed that lax regulations at the state and federal level were part of the probable causes of the explosion.
The board said that substandard welds and other problems dating back to the 1956 installation of the gas transmission line laid the ground for the accident.
"It was not a question of if this pipeline would burst. It was a question of when,'' Hersman said during the hearing.
Among PG&E's failures stated Tuesday were some that dated back decades. They included faulty
record-keeping, using "woefully inadequate pipe" during the 1956 installation of the ruptured line, insufficient inspections and a weak emergency response plan, Hersman and NTSB investigators said.
"Our investigation revealed that for years, PG&E exploited weaknesses in a lax system of oversight," said Hersman. "We also identified regulators that placed a blind trust in the companies that they were charged with overseeing to the detriment of public safety."
Investigators noted that PG&E also missed two prior opportunities to address shortcomings in its pipeline system, after similar systemic problems emerged following incidents on the company's pipelines in 1981 in San Francisco and 2008 in Rancho Cordova.
The NTSB board made a series of safety recommendations to regulators and the gas industry before adjourning. It concluded the explosion wasn't the result of a simple mechanical failure, but was an "organizational accident."
Below are a few quotes of note from today's testimony.
1) "There was no single source (at PG&E) getting the information," Bob Trainor.
2) " When police called PG&E (to report the blast/fire), PG&E had no queries as to the nature of the fire," Trainor said.
3) There was sufficient information within 10 minutes that there was a line break. This should have prompted an urgent response. "It didn't." -- Trainor said.
4) There was no evidence of anyone telling investigators that the welds were inspected/maintained by PG&E. There was also no requirement for inspection or regulation for a long period in the pipeline's lifetime.
5) No reliable documents within PG&E were surfaced as to the maintenance of these pipeline segments.
6) "A segment is only as strong as its weakest link," Matthew Nesbitt said.
7) "Quality assurance and quality control was not adequate," Trainor said.
----- Official Documents -----
- PDF: The chief investigator's opening statement from the NTSB's San Bruno explosion hearing on Aug. 30, 2011.
- PDF: Opening statement from the hearing's chairman on behalf of the NTSB.
- PDF: The overall agenda for the Aug. 30, 2011, hearing about the San Bruno Explosion.
The NTSB issued the following release at the conclusion of the hearing:
Today the five-member National Transportation Safety Board cited a California utility operator's lax approach to pipeline safety and the inadequate oversight of two government agencies in the probable cause of the most devastating pipeline accident in a decade.
"Our investigation revealed that for years, PG&E exploited weaknesses in a lax system of oversight," said NTSB Chairman Deborah A.P. Hersman. "We also identified regulators that placed a blind trust in the companies that they were charged with overseeing to the detriment of public safety."
At about 6:11 p.m. (PDT) on September 9, 2010, a 30-inch diameter segment of a natural gas transmission pipeline, owned and operated by PG&E, ruptured in a residential neighborhood in San Bruno, California. The force of the rupture ejected a 3000-pound 28-foot-long section of pipe about 100 feet from where it had been buried four feet underground. The released natural gas ignited into a towering fire that destroyed 38 homes and damaged 70. As a result, eight people were killed, dozens were injured, and many more were evacuated from the area and displaced from their homes.
The nearly year-long NTSB investigation revealed that PG&E did not know what kind of pipe it had installed beneath the city of San Bruno in 1956. PG&E records initially provided to NTSB investigators indicated that the ruptured section of pipe was a 30" seamless pipe when in fact, at the time, no manufacturer produced seamless pipe.
Investigators also determined that the ruptured section of pipe was a collection of short pipe pieces, commonly known as "pups," joined together with welds. Further metallurgic assessment by NTSB investigators determined that some of the pipe sections did not meet minimum material specifications and that the welds were poorly constructed.
The defective welds would have been visibly detectable at the time of the installation, but, because of PG&E's inadequate quality control during the construction project and its failure to maintain accurate records, the poorly welded section of pipe went undetected for over 50 years. Failure of one of the improperly welded seams caused the Sept. 9, 2010, rupture during an increase in pressure resulting from repair work being performed at a terminal upstream of the rupture site.
The Board determined that the accident was clearly preventable stating that PG&E's inadequate pipeline integrity management program failed to identify, detect, and remove the substandard pipe segments before they ruptured.
"This tragedy began years ago with PG&E's 1956 installation of a woefully inadequate pipe," said Chairman Hersman. "It was compounded by a litany of failures - including poor recordkeeping, inadequate inspection programs, and an integrity management program without integrity."
In its examination of the history of oversight of PG&E, the NTSB found that two key regulatory decisions (one by CPUC in 1961 and one by PHMSA in 1970), which "grandfathered", or exempted, older pipelines from the testing protocols required of newly constructed ones, allowed the flawed pipe to escape detection.
The Safety Board found that CPUC, did not effectively evaluate or assess the safety of PG&E's integrity management program. On the federal side, the NTSB said that PHMSA's grandfathering of pre-1970 pipe contributed to the accident.
"For government to do its job - safeguard the public - it cannot trust alone, it must verify through effective oversight," said Hersman. "As we saw in San Bruno, when the approach to safety is lax, the consequences can be deadly."
At the meeting today, the NTSB made a total of 29 safety recommendations to PG&E, CPUC, PHMSA, the American Gas Association, the American Petroleum Institute, the Gas Technology Institute, the Interstate Natural Gas Association of America, the International Association of Fire Chiefs, the International Association of Firefighters, and the National Volunteer Fire Council.
During the course of the investigation, the NTSB issued 10 safety recommendations (six of them classified as urgent) to PG&E, PHMSA and CPUC to address issues in record-keeping, information sharing, pipeline testing, and emergency preparedness and notification procedures.
PG&E President Chris Johns attended the hearing. He said PG&E has spent the past
year making fundamental changes to its operations that will put safety first.
"We fully embrace the recommendations of the NTSB and will incorporate them into our plans,'' Johns said in a statement.
He also said the company's board was "deeply sorry that our pipeline was the cause'' of the accident.
"We know that nothing we can say nor any action we can take will ever make up for the losses experienced by the victims of the accident and the San Bruno community,'' Johns said.