The following story by Jaxon Van Derbeken was published Sept. 26, 2011 on sfgate.com.
Much of Pacific Gas and Electric Co.’s natural-gas transmission system could be at risk of catastrophic failure, but the company’s record-keeping system is so flawed that the true danger is impossible to determine, federal investigators said Sept. 26 in their final report on last year’s San Bruno disaster.
The National Transportation Safety Board said PG&E had made numerous mistakes in the management of its transmission-pipeline system, including its failure to test more widely for substandard welds after finding several on the pipeline that exploded Sept. 9, 2010, and on other pipelines.
Citing “multiple and recurring deficiencies in PG&E operational practices,” the safety board found that PG&E suffers from a “systemic problem” related to safety.
The report also said state and federal regulators had not done enough to ensure the company was running a safe system, putting what the safety board’s chairwoman called “blind trust” in PG&E despite a dismal track record.
Although PG&E says it has made several reforms designed to improve safety, the federal agency said it remained concerned about the state of the company’s record-keeping.
PG&E’s records database, the safety board said, “still has a large percentage of assumed, unknown or erroneous information” about the San Bruno line “and likely its other transmission pipelines as well.”
“The lack of complete and accurate pipeline information,” the board concluded, has “prevented PG&E’s integrity management program from being effective.”
PG&E had ample warning signs over more than 60 years about the San Bruno pipeline, known as Line 132, that should have led it to perform the type of inspection capable of finding the incomplete longitudinal seam weld that failed last September, the safety board said. The weld’s rupture triggered the explosion that killed eight people, destroyed 38 homes and damaged 70 others.
The first warning sign came in 1948, when four “rejectible” seam welds were uncovered in a small-scale survey during the installation of Line 132, the safety board said.
Other warnings followed after the portion of the line that exploded was constructed in 1956.
In 1988, a flawed seam weld led to a leak on Line 132 nine miles south of the eventual blast site, but PG&E listed the cause as unknown and relegated the records to accounting files.
In 1992, PG&E found another flaw in a seam weld on Line 132, the report said. The company found two more seam weld problems in similar pipe in nearby Line 109 in 1996, and several additional flawed welds in other parts of its system, the federal agency said.
But PG&E did not consider such seam weld flaws as a risk to a particular line unless two flaws were found within one mile of each other, the safety board said.
The board did not mention a PG&E contractor’s discovery in October 2009 of a flawed seam weld on Line 132 just two miles north of the blast site. The Chronicle reported the discovery last month after PG&E included it in a filing of 250,000 pages of documents with the state.
Based on the federal agency’s findings, “the odds of not having another seam weld flaw are about 1 in a trillion,” said Richard Kuprewicz, an independent pipeline safety consultant who has been reviewing the utility’s compliance program for The Utility Reform Network advocacy group.
PG&E has embarked on a review of its records as well as a high-pressure water testing program to verify the safety of its lines since the blast. It has tested about 40 miles of transmission line so far.
The company issued a statement Monday pledging to implement changes throughout its system “to promote safer pipeline operations.”
“We are committed to continuing to learn from the San Bruno accident and to sharing those learnings across the natural gas industry so that a tragedy of this magnitude never happens again,” said company President Chris Johns.
Deborah Hersman, the federal safety board’s chairwoman, faulted both PG&E and regulators in a statement in support of the findings.
“PG&E exploited weaknesses in a lax system of oversight,” Hersman said. “We also identified regulators that placed a blind trust in the companies that they were charged with overseeing – to the detriment of public safety.”
The safety board’s full report can be read at www.ntsb.gov.