Defective Weld in PG&E's Pipeline Led to Explosion

An NTSB report points to "systemic problem" and finds strong similarities between the Sept. 9 San Bruno fire and the 2008 Rancho Cordova explosion, in which PG&E’s poor handling of a pipeline’s installation ultimately led to that accident.

The likely cause of the Sept. 9 San Bruno pipeline explosion was PG&E’s inadequate handling of Line 132 in which a poorly welded section of pipe expanded over time and ruptured into a fireball when gas pressure suddenly spiked, the National Transportation Safety Board concluded in a report released today.

The agency found that Pacific Gas & Electric Co.’s integrity management program, which was supposed to detect flaws in its pipelines, failed to find or repair the weak section of Line 132, leading the pipeline to explode.

The conclusions in the report were not surprising, as the NTSB’s year-long fire investigation had already identified numerous failings in how PG&E operated the pipeline that ruptured in the Crestmoor neighborhood. What was most surprising in the report is how similar last year’s accident is to the , in which PG&E’s poor handling of that pipeline’s installation ultimately led to that accident. The 2008 blast killed one person and injured five others.

“PG&E’s multiple, recurring deficiencies are evidence of a systemic problem,” the report concluded.

PG&E spokesman Brian Swanson told Patch that his company is committed to strictly complying with the NTSB’s conclusions.

“We will adopt all of (the NTSB’s) safety recommendations,” Swanson said. “At the end of the day, it is our pipeline and it is our responsibility to operate that pipeline safely.”

Many theories have circulated about what could have caused the 30-inch natural gas pipeline to explode on that tragic September night, leaving eight people dead and 38 homes destroyed.

Those theories were strengthened by findings made public about PG&E’s operations throughout the NTSB’s investigation, which revealed the following safety problems:

  • Multiple deficiencies in PG&E’s operations, such as faulty record-keeping;
  • An incomplete integrity management program, which used a method called direct assessment to inspect its natural gas pipelines. That method, however, is best used to detect corrosion and not flaws in pipelines that have longitudinal seam welds such as Line 132;
  • Improper oversight of its computerized system that monitored and maintained the pressure in the pipeline, known as SCADA (Supervisory Control and Data Acquisition), and its unorganized emergency response to the disaster;
  • Ineffective federal and state oversight;
  • Inadequate federal pipeline safety rules, which PG&E was able to circumvent because it installed many of its lines before certain policies were established.

A along the pipe’s longitudinal seams ultimately led the NTSB to determine the probable cause of the explosion. According to the latest report, PG&E overlooked safety precautions when Line 132 was installed in the Crestmoor neighborhood in 1956.

With that misstep, and the lax oversight of federal and state regulators, PG&E workers were completely caught off guard when, moments before the pipeline ruptured, the electrical system malfunctioned 39 miles away at the utility’s Milpitas terminal, causing the gas pressure to spike past its maximum operating pressure of 375 pounds.


State, national agencies share blame

PG&E, however, wasn’t the only entity at fault for the fire, the NTSB found.

Contributing to the accident was the fact that the California Public Utilities Commission and the federal Pipeline and Hazardous Materials Safety Administration, which both regulate pipeline operators in California, allowed PG&E to be exempt from certain requirements for pressure testing its lines.

On top of that, PG&E on its pipelines and proper emergency response procedures that could have significantly prevented the extensive damage to the neighborhood.

The accident happened because of “a company that exploited weaknesses in a lax system of oversight and government agencies that placed blind trust in operators to the detriment of public safety,” NTSB Chairwoman Deborah Hersman said today.

The NTSB released 28 findings that were discovered during its investigation and issued 29 new recommendations as a result of the accident. Among the findings are that:

  • Neither seismic activity, corrosion, the near Line 132, nor at the Milpitas Terminal were factors in the blast.
  • Had a properly prepared contingency plan for the Milpitas Terminal electrical work been in place and executed, the loss of pressure control could have been anticipated and planned for, thereby minimizing or avoiding the sudden spikes in gas pressure.
  • If the grandfathering of older pipelines had not been permitted since 1961 by the CPUC and since 1970 by the U.S. Department of Transportation, Line 132 would have undergone a hydrostatic pressure test that would likely have exposed the defective pipe that led to the accident.
  • The ineffective enforcement posture of the California Public Utilities Commission permitted PG&E’s organizational failures to continue over many years.

The NTSB report brought some satisfaction to several San Bruno residents who lived in the affected area, even if it took the agency a year to confirm what they said common sense already made clear.

“My first reaction is ‘yeah,’ the NTSB seems to have gotten it right,” said Bill Magoolaghan, who lost his home in the blast. “(The NTSB) seems to in very stern and harsh language call out PG&E for the inadequacies and negligence that have been built into their system over the last decade that caused this explosion.”

Others had similar sharp criticism of PG&E.

“PG&E had an integrity management program without integrity,” said Kathy DeRenzi, a Crestmoor neighborhood resident. “I can only hope now that PG&E takes this opportunity to put safety at the top of their list rather than their executive salaries. I know that someone above is watching over the CPUC and making them now finally step up to do their job.”

Robert Pellegrini, who lost his home in the blaze, said he found PG&E’s cost-cutting described in the NTSB report to be “appalling.”

“I know the CPUC was very lax in regulating PG&E, but ultimately it was their lack of integrity and being more diligent in managing their system” that led to the explosion, Pellegrini said.


Residents remain wary

But while the NTSB report has brought a sense of vindication to many residents, it has failed to bring closure to those who were hoping the agency would go beyond recommendations and seek the establishment of more stringent regulations.

“Part of me feels happy about what the NTSB has said,” Magoolaghan said. “It confirms our beliefs and it confirms everything that we’ve seen in the press and everything that we’ve heard. So it’s nice to have that affirmation. However, the big question is: so what? What now? What does it matter? And what do we do now about it?

“They have a lot of recommendations and the recommendations are right on, but my only question about the NTSB is how much authority do they really have, and to have suggestions and recommendations rather than requirements seems a little bit odd.”

The NTSB’s failure to call for specific regulatory measures is disconcerting to San Bruno residents who simply don’t trust PG&E or the CPUC and its willingness to aggressively monitor the utility.

Magoolaghan said he rates the CPUC and PG&E a five out of 10 on a trustworthy scale.

“If history is any indication of how sincere the CPUC and PG&E are, then obviously we have something to worry about,” he said.

“You haven’t changed that many people at either of the organizations to think that the culture is going to change.

“There’s two faces to PG&E. There's the PR side that seems to say all the right things, and the other is the legal team that says things as outrageous as ‘San Bruno residents caused the explosion themselves’ and blames everybody but themselves.”

Swanson said the company’s for the explosion were out of line and he acknowledged PG&E’s spotty track record.

“It’s clear that our past operations and records keeping practices are not where they should have been,” he said.

Asked why its customers should have any greater confidence in PG&E’s commitment to public safety than before the explosion, Swanson said a shakeup in the company’s leadership has signaled a shift in its priorities.

The company has hired a and who “have a mandate to change the culture to make it more focused on safety.”

Additionally, PG&E has hired 90 new gas engineers as an additional resource to improve safety and performance of its gas operations.

Swanson said PG&E is committed to doing what it can to help San Bruno recover from the tragedy, but he acknowledged that ultimately his company will be judged by its actions, not its rhetoric.

And while for many the NTSB report offers some closure, for others, it also opens up some old wounds.

“Even though I and many of the residents have been waiting for the NTSB report, it’s been stirring a lot of emotions that many are trying to get past,” Pellegrini said. “It’s kind of re-living the whole incident again.”

Mayor Jim Ruane, who along with several other city officials traveled to Washington, D.C., to listen to the NTSB give its report, said it’s unfortunate that the tragic accident can’t be undone. But he feels the city can take another step forward in its recovery, knowing that the NTSB made some strong recommendations.

“That chapter is behind us now, but another chapter has opened up,” he said by phone. “Now, we’ll have to work closely with the residents and with congressional and state legislators to make tighter rules so that this doesn’t happen again.”


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