Washington -- (Published Aug. 31, 2011)

Federal investigators pinned blame Tuesday squarely on Pacific Gas and Electric Co. for the natural gas pipeline blast in San Bruno, condemning shoddy company safety practices for the devastation of a neighborhood and the deaths of eight people.

The National Transportation Safety Board, wrapping up a nearly yearlong investigation, also said federal and state pipeline regulatory efforts need to be overhauled to prevent another city from suffering such a disaster.

A seam weld in the pipeline segment that ruptured Sept. 9 in San Bruno was so obviously deficient that it would not have passed even a cursory visual inspection when a PG&E crew installed it in 1956, investigators with the safety board said. The weld flaw, and PG&E's failure over more than 50 years to conduct an inspection that would have detected it, made the line's rupture inevitable, they said.

"It was not a question of if this pipeline would burst," safety board Chairwoman Deborah Hersman said at a hearing at which the agency presented its findings. "It was a question of when."

PG&E compounded the danger through "poor record keeping, inadequate inspection programs and an integrity management program without integrity," Hersman said before the five-member safety board voted unanimously to blame the explosion on the company.

PG&E's final mistakes happened the day of the blast, the safety board said, as a botched repair job set the disaster in motion and control-room operators failed to recognize what had happened for several precious minutes as the San Bruno neighborhood burned.

Homeowners paid the price for PG&E's longtime resistance to installing automatic pipeline shutoff valves, as it took the company more than 90 minutes to close manual valves and cut the flow of gas to the inferno. When the flames finally were extinguished, 38 homes were destroyed and 70 were damaged.

Lax regulation

It wasn't just what Hersman called PG&E's "litany of failures" that came in for criticism. The board chairwoman said the company had "exploited weaknesses in a lax system of oversight, and regulatory agencies that placed a blind trust in operators to the detriment of public safety."

Many of the 29 recommendations that the safety board approved Tuesday were aimed at turning the San Bruno explosion into a wake-up call both for government and for the pipeline industry nationwide.

The board called for federal regulators to repeal "grandfather" regulations that allowed pipelines installed before 1970, including the one in San Bruno, not to be tested using high-pressure water, a method that is effective at finding defective welds.

The safety board also pushed for requirements that PG&E and other utilities install automatic shutoff valves in pipelines in populated areas.

In a proposal that hints at the monumental task ahead, the safety board asked that gas transmission pipelines around the country be reconfigured to allow for testing for defects with in-line tools known as smart pigs. Currently, more than half of the nation's gas transmission lines cannot accommodate such tools because they are filled with narrow turns and bends.

'Too late' for city

San Bruno sent a delegation of leaders to the hearing, and Mayor Jim Ruane said he was satisfied with the federal findings that PG&E was solely to blame.

"It's too late for our city, but it's not too late for other communities," Ruane said.

As for the city regaining confidence in PG&E, he said, "They have a long way to go."

Bill Magoolaghan, who is living with his wife and four young children in a Belmont rental while they rebuild their burned-out home in San Bruno, watched the hearing on the Internet. He welcomed the safety board's conclusions, but remained uneasy about the future.

"Now what?" he asked. "Recommendations and suggestions don't cut it. I need something much more firm. I need requirements. I need legislation. I need the safety board to tell the California Public Utilities Commission to fine PG&E an ungodly amount of money. It should be a staggering, record fine that PG&E will take seriously."

PG&E issued a statement after the hearing that said, "We fully embrace the recommendations of the NTSB and will fully incorporate them into our plans. Although we have much to learn and do, we have already taken many immediate and long-term steps to promote safety."

State promises changes

California Public Utilities Commission Executive Director Paul Clanon said he, too, welcomes the recommendations, including a call for a federal audit of his agency's effectiveness as well as a state audit of PG&E's safety program.

He said his agency had ordered utilities to "test or replace all grandfathered pipes" and is looking at "plans that include valve automation and retrofitting pipelines to accommodate in-line inspection tools."

Hersman traced the Sept. 9 disaster to PG&E's installation of a "woefully inadequate pipe," whose source remains unknown. At the rupture site at Earl Avenue and Glenview Drive, which sits at the low point of a canyon, PG&E cobbled together six short pieces known as pups, allowing the line to negotiate the curve of the canyon.

Hersman and safety board investigators said five of the pipe pieces did not meet PG&E or industry standards in place at the time. The one that failed had been welded along its longitudinal seam from the outside, but not the inside, leaving it prone to a break. The board concluded that it was not a factory-manufactured piece of pipe, rejecting PG&E's claim that a defunct steel company had made it.

The safety board said the weak pups would not have withstood specialized testing, such as the use of high-pressure water, for defective longitudinal seam welds. But PG&E never did such tests on the line and checked the pipe only for corrosion. Company records erroneously indicated that the line was seamless and thus had no seam welds.

"That pipe should not have been installed," said Donald Kramer, a metallurgical expert for the safety board who found the pipe to be riddled with substandard welds. "It's not supposed to be there."

Another investigator, Robert Hall, criticized PG&E's pipeline safety program for its approach to potential risks. He said the company had put too much emphasis on spotting problems caused by ground movement and third parties like construction crews, and too little emphasis on detecting design flaws.

Poor reactions

The federal safety board said PG&E had missed two earlier opportunities to fix problems in its gas operation - a 2008 explosion of a distribution line in the Sacramento suburb of Rancho Cordova, in which a leak in a substandard pipe caused a blast that killed a homeowner, and a 1981 incident in San Francisco's Financial District in which the utility took nine hours to shut off gas from a pipe that exploded.

The problem in San Francisco was with manual shutoff valves, one of which had been paved over, investigators found. Despite being warned, PG&E resisted adding automatic valves, a stance it didn't change until after the San Bruno disaster.

The immediate cause of the San Bruno explosion was PG&E's loss of control of the gas pressure on the pipeline late the afternoon of Sept. 9, due to problems with the power supply during a repair job at the pipeline's southern terminus in Milpitas.

The federal probe found that the power problems resulted in erroneous indications of low pressure being sent to pipeline valves, causing those valves to swing wide open and pressure on the line to surge. The crew doing the repair job had no contingency plan to deal with the problem, investigators said.

PG&E's lack of an emergency plan, muddled communications and the absence of automatic shutoff valves resulted in the company taking 95 minutes to halt the flow of gas, the safety board said.

"We believe they had information within 10 minutes to know they had a line break," investigator Robert Trainor said of PG&E's pipeline operators. "That should have prompted an urgent response, but it did not."

While saying they could not identify exactly what caused earlier cracks on the defective seam weld, federal investigators said previous stresses to the line included pressure spikes that PG&E ordered in 2003 and 2008.

Hall, the safety board investigator, said after the hearing that investigators can't be certain about what role pressure spikes played because PG&E records are incomplete.

"We only had pressure records over the last 10 years," Hall said. "There's 40 years of history where we don't have a record on how it operated."

The safety board ruled out the possibility that a sewer line replacement project that San Bruno commissioned in 2008 had stressed the line and contributed to the accident. A blue-ribbon panel commissioned by the California Public Utilities Commission had said the sewer project was a likely contributing factor, as did a pipeline industry group.

Jaxon Van Derbeken reported from Washington and Demian Bulwa from San Francisco.