Feds fear for safety of PG&E’s gas system
by Jaxon Van Derbeken, San Francisco Chronicle
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 Monday 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 defects 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 suffered 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, instead placing what the safety board’s chairwoman called "blind trust" in PG&E despite a dismal track record.
The safety board’s 140-page report provides factual findings to back up its conclusion last month that a "litany of failures" by PG&E over more than five decades led to the explosion that killed eight people, destroyed 38 homes and damaged 70 others.
Although PG&E says it has made several reforms designed to improve safety, the federal agency said in its report that it remains 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."
The company has struggled to find paperwork for all its 1,800-plus miles of transmission pipeline since the San Bruno disaster, and has never located critical documents about the cobbled-together assortment of substandard pipe pieces that made up the line at the explosion site.
Based on the federal agency’s findings, the odds of not having another defect like the one that destroyed the San Bruno pipe "are about 1 in a trillion," said Richard Kuprewicz, an independent pipeline safety consultant who has been reviewing PG&E’s compliance program for The Utility Reform Network advocacy group.
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 and led to the blast, the safety board said.
Years of warning signs
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 rerouted to make way for the Crestmoor subdivision in 1956.
In 1988, a flawed seam weld led to a leak on Line 132 less than 9 miles south of the eventual blast site, but PG&E listed the cause as unknown and relegated the records to accounting files. Although PG&E records indicate that the company examined the failure, it has not been able to find the report.
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 on nearby Line 109 in 1996 and several additional flawed welds in other parts of its system, the federal agency said.
The safety board did not mention a PG&E contractor’s discovery in October 2009 of a flawed seam weld on Line 132 just 2 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.
PG&E did not consider such seam weld flaws as a risk to a line unless two flaws were found within 1 mile of each other, the safety board said.
Considering all that is now known about Line 132, the pipeline’s operating pressure should not have gone above 284 pounds per square inch, the federal safety board said. PG&E’s pressure cap on the line was 400 pounds, but the company plans to operate it at half that level when it returns the line to service this winter.
PG&E said it used a "conservative approach" when assessing what risks a pipeline might face, but the safety board said the company often ignored apparent problems and assigned "non-conservative" values if it couldn’t find records.
When it came to Line 132 and similar pipelines, "leaks on more distant pipe segments of the same vintage, same characteristics and same manufacturer are not considered," the report said. It called that "a concern, because PG&E used pipe of the same vintage, same characteristics and same manufacturer" throughout its system, "spanning multiple miles and separate lines."
On the San Bruno pipe and some other lines, PG&E boosted pressure to maximum allowable levels once every five years under the misguided belief that federal law required it, the safety board said. The company feared that the alternative could be mandatory tests using high-pressure water, something that would require the temporary shutdown of a line.
One California official called such intentional spikings "a wrong-headed approach to safety," and the federal board said it was possible that the increases "progressively weakened" Line 132 before the blast. PG&E abandoned the practice after the San Bruno disaster, although the company insisted it had been safe.
PG&E has made several other changes since the blast, including embarking on a review of its records and pressure-testing some of its most problematic lines. The company has tested about 40 miles of gas transmission line so far.
PG&E 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."