Update 2:25 p.m. The NTSB has posted the Executive Summary of its Pipeline Accident Report, which includes 28 findings. Read it here.
The NTSB says this under a section called Probable Cause:
The National Transportation Safety Board determines that the probable cause of the accident was the Pacific Gas and Electric Company's (PG&E)
(1) inadequate quality assurance and quality control in 1956 during its Line 132 relocation project, which allowed the installation of a substandard and poorly welded pipe section with a visible seam weld flaw that, over time grew to a critical size, causing the pipeline to rupture during a pressure increase stemming from poorly planned electrical work at the Milpitas Terminal; and
(2) inadequate pipeline integrity management program, which failed to detect and repair or remove the defective pipe section.
Contributing to the accident were the California Public Utility Commission's (CPUC) and the U.S. Department of Transportation's exemptions of existing pipelines from the regulatory requirement for pressure testing, which likely would have detected the installation defects. Also contributing to the accident was the CPUC's failure to detect the inadequacies of PG&E's pipeline integrity management program.
Contributing to the severity of the accident were the lack of either automatic shutoff valves or remote control valves on the line and PG&E's flawed emergency response procedures and delay in isolating the rupture to stop the flow of gas.
Some of the more interesting findings:
- The accident pipe would not have met generally accepted industry quality control and welding standards in 1956, indicating that those standards were overlooked or ignored.
- PG&E's inadequate quality control during the 1956 relocation project led to the installation and commissioning of a defective pipe that remained undetected until the accident, 54 years later.
- The 2008 sewer line installation did not damage the defective pipe that later ruptured.
- The internal line pressure preceding the rupture did not exceed the PG&E maximum allowable operating pressure for Line 132 and would not have posed a safety hazard for a properly constructed pipe.
- PG&E lacked detailed and comprehensive procedures for responding to a large-scale emergency such as a transmission line break, including a defined command structure that clearly assigns a single point of leadership and allocates specific duties to supervisory control and data acquisition staff and other involved employees.
- The 95 minutes that PG&E took to stop the flow of gas by isolating the rupture site was excessive.
- Use of automatic shutoff valves or remote control valves along the entire length of Line 132 would have significantly reduced the amount of time taken to stop the flow of gas and to isolate the rupture.
The board also makes 29 recommendations to six different entities, including PG&E, CPUC, the federal Pipeline and Hazardous Materials Safety Administration, and the Governor of California. Many of the recommendations are for new regulations or the toughening of old regulations.
KQED Radio's Cy Musiker will be talking with South Bay Congresswoman Jackie Speier about the report at 5:30 p.m. Speier, who sent out many tweets from the hearing today, has been a fierce critic of PG&E. You can listen to that live on the radio or right here online. Check here for an archive of the discussion afterward.
The Bay Citizen has a really good wrap-up of the NTSB findings in its live blog of today's hearing:
To recap, the five members of the National Transportation Safety Board voted unanimously that PG&E's deficient pipeline management system - from the 1950s until the present time - was the "probable cause" of the Sept. 9, 2010 San Bruno pipeline disaster, which killed eight people. Deficient oversight by state and federal regulators were "contributing causes," the board ruled. PG&E's response to the disaster and its lack of emergency preparedness increased the severity of the accident, the board ruled...
Other findings adopted unanimously by Board: San Bruno's 2008 sewer project did not contribute to the accident; The pipeline didn't meet 1950s standards; The pipeline fracture began along an deficient weld; PG&E lacked a comprehensive plan for responding to such a disaster; The 95 minutes that PG&E took to shut off the flow of gas to the rupture was exceessive; Local emergency workers and agencies coordinated their response to the disaster well; PG&E's post-accident drug and alcohol testing program was inadequate; There is no basis to exempt old pipelines from modern inspection rules; PG&E's gas transmission integrity program was deficient and ineffective; And the disaster was the result of an "organizational accident" - ie, there was no single cause of the accident, instead it was the culmination of systemic failures within PG&E.
And here's a little taste of the kind of shellacking PG&E took today. After rattling off a welter of systemic problems delineated in the NTSB final report, board member Robert Sumwelt sounds incredulous when he asks one of the investigators on the panel, "how does an organization get to the point where they have all these deficiencies?" Listen below...
Update 1:05 p.m. Over the past year, the San Francisco Chronicle has done a lot of terrific investigative reporting on this story. Here's reporter Jaxon Vanderbeken summarizing some of what the paper discovered:
Here are two recent reports by Van Derbeken worth reading:
- PG&E missed opportunity to head off the disaster (SF Chronicle)
Pacific Gas and Electric Co. knew in fall 2009 that an inspection crew had stumbled onto cracks and defective welds on the San Bruno gas transmission line near where the pipe ruptured at a similarly flawed weld 11 months later, but failed to check for such problems elsewhere on the line, company e-mails and documents reviewed by The Chronicle show.
- PG&E knew of vulnerable welds in 2008, memo shows (SF Chronicle)
Pacific Gas and Electric Co. knew in 2008 that the San Bruno gas line that later exploded and the network of smaller pipes it fed had multiple potentially at-risk welds, but decided to spike the system's pressure so it could avoid the possibility of costly inspections, according to a company memo turned over to federal investigators.
- Considering the challenges of the prolonged fire fueled by natural gas, the emergency response was well coordinated and effectively managed by local responders.
- If the grandfathering of older pipelines had not been permitted since 1961 by the California Public Utilities Commission 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 this accident.
- There is no safety justification for the grandfather clause exempting pre-1970 pipelines from the requirement for postconstruction hydrostatic pressure testing.
- The PG&E gas transmission integrity management program was deficient and ineffective.
- The ineffective enforcement posture of the California Public Utilities Commission permitted PG&E's organizational failures to continue over many years.
The NTSB has concluded a nearly year-long investigation (final report should be posted here later) into the San Bruno gas pipeline explosion, and PG&E is coming under a lot of fire from the panel presenting the results today. From NTSB Chair Deborah Hersman's opening salvo:
"Today you're going to hear about flawed pipe, flawed operations, and flawed oversight. It was not a question of if this pipeline would burst, it was a question of when." (Audio of that here.)
Update 10:48 a.m. The Bay Citizen is live-blogging the hearing.
Update 8:45 a.m. Here's Hersman's opening statement, and it's a dilly. For those looking for a federally sanctioned catharsis to their frustration and/or despair over San Bruno, this might provide a dose. Here's Hersman's closing slam of both PG&E and its state regular, the California Public Utilities Commission:
This accident represents a snapshot in time, and we recognize that individuals in the system work hard every day – at PG&E, CPUC, and PHMSA – to keep our pipelines safe. But good intentions did not prevent this accident from happening, Opportunities were missed that could have – and should have – prevented this tragedy. We acknowledge that in the intervening months since the accident, much has been learned and commitments to change have been made. But we're here today to talk about what led to the rupture on September 9, 2010.
Today, you will hear troubling revelations … about a company that exploited weaknesses in a lax system of oversight and government agencies that placed a blind trust in operators to the detriment of public safety.
We know now that this tragedy began years ago with PG&E's 1956 installation of a woefully inadequate pipe. It was compounded over the years by a litany of failures — including poor recordkeeping, inadequate inspection programs, and an integrity management program without integrity.
This is not the first NTSB investigation involving PG&E. In August 1981, following a pipeline rupture in San Francisco, it took PG&E more than nine hours to shut down the gas flow. The NTSB found inadequate recordkeeping as a contributing cause in that event.
Then, in the investigation of a 2008 house explosion caused by PG&aamp;E's gas distribution pipeline in Rancho Cordova, California, NTSB identified similar issues, including lack of quality control during pipe installation and inadequate emergency response procedures.
Now, it's Sept. 2010. Another explosion. Eight people killed.
Today, you will hear about flawed pipe ... flawed operations ... flawed oversight.
It was not a question of if this pipeline would burst. It was a question of when.
Also, on KQED Radio's Forum at 9 a.m., an hour-long discussion on the NTSB final report. Listen live here, or to the archived show later in the day. Guests include Congresswoman Jackie Speier, San Bruno Mayor
Jim Ruane, and San Jose Mercury News reporter and managing editor of KQED Quest Paul Rogers.
Finally, live #sanbruno tweets below, including a bevy from Congresswoman Jackie Speier, whose district includes San Bruno and who has been extremely critical of PG&E, and a couple from the company itself. A sampling of this study in alternate realities: