PG&E missing key San Bruno documents
August 16, 2011
New federal findings, released Monday, report that Pacific Gas & Electric is unable to find key documents about the section of natural gas pipeline that exploded last fall in San Bruno and has depended on faulty or nonexistent data to vouch for the safety of the rest of the pipeline. [Chronicle]
National Transportation Safety Board (NTSB) investigators remain hampered by a lack of specific information about the section of pipe that exploded Sept. 9, killing eight people and destroying 38 homes.
Although PG&E provided about 300 pages to the safety board related to a 1956 pipe rerouting project near the rupture site, its “documentation does not include PG&E’s specifications, purchase orders for new pipe, inspection records, foreman’s log books, as-built drawings or (X-ray) radiography reports,” according to the NTSB report.
Without PG&E having produced basic records about the pipeline, it is unclear how the company chose a method in recent years to comply with federal law mandating that pipeline operators inspect older pipes. Operators are required to review pipeline histories before choosing a method.
PG&E said earlier this year that it had been unable to produce all documents vouching for the safety of about a quarter of its 1,800 miles of gas transmission pipeline in Northern and Central California. The state ordered PG&E to find such documents after federal investigators discovered that the company incorrectly believed the ruptured part of the San Bruno pipeline had been built without longitudinal seams.
UC Berkeley engineering Professor Robert Bea, who has followed the federal government’s probe, said PG&E’s inability to produce such key documentation this far into the investigation is disturbing. “It speaks volumes that they can’t find it,” Bea said.
PG&E’s lack of documentation about the San Bruno section of pipe is repeated at other spots along the 51 miles of the transmission line running from the South Bay to San Francisco, the federal safety board said.
Investigators have found that the company does not know the thickness of the pipe’s walls for 21 miles, does not know who manufactured more than three-quarters of the line and does not know how deeply the pipe is buried for more than 40 miles of its course.
Federal investigators also found that at some segments where PG&E lacks data, it made overly optimistic assumptions about the pipe’s strength rather than figuring on a lower level, as industry practice requires.