PG&E To Begin Mandated Pipeline Pressure Testing
SAN BRUNO (KCBS/AP) - After the deadly explosion in San Bruno on Sept. 9, state regulators ordered Pacific Gas & Electric Co. to produce records for its pipelines through urban areas or test them - the agency said Tuesday that some of that work will begin in May.
KCBS' Holly Quan Reports:
Many experts and local politicians said this is the kind of rigorous testing that the utility should have used to test lines like 132, which blew up last September in San Bruno.
"I think this is the beginning of many steps that will need to be taken before we really have confidence again that PG&E is operating a safe gas transmission system," said Peninsula Assemblyman Jerry Hill. "I think it's a good step and I think they're doing it in a very timely manner."
Federal investigators have not determined a cause but suspect the pipeline may have burst under high pressure.
Photo Gallery: San Bruno Pipeline Explosion
The company will conduct water pressure, or "hydrostatic," testing to determine the reliability of numerous pipeline segments throughout its service area, mostly those beneath densely populated or "high consequence areas," PG&E spokesman Joe Molica said.
"A portion of that is going to be in the Bay Area," Molica said.
The first pressure tests will take place in Antioch and Mountain View, and PG&E prioritized the pipelines to be tested based on their similarities to Line 132, which exploded when it ruptured on Sept. 9, 2010, killing eight people.
Molica said Line 132 was installed before the state began requiring pressure testing in 1962, it was between 24 and 36 inches in diameter, and there were incomplete records regarding pressure tests.
Hydrostatic pressure testing involves filling a section of pipe with water, pressurizing it to a higher level than it would operate with natural gas, then monitoring it for eight hours, Molica said.
If the test is successful and the pipe is determined to be sound, the section is emptied, dried and put back into service.
PG&E will be holding open house meetings for Mountain View and Antioch residents regarding hydrostatic testing in their neighborhoods.
The dates and times of the meetings will be announced in a letter PG&E is sending to residents this week.
The process does require sections of pipeline to be taken out of service for several days, Molica said, though the utility will avert interrupting service to homes and businesses by using alternate pipelines.
PG&E will also be conducting an engineering analysis of pipelines running through high consequence areas, which could include taking X-rays of welds and seams and inspecting the interiors of pipes with robotic cameras.
(Copyright 2011 by CBSSan Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. Wire services may have contributed to this report.)
