A PG&E pipeline that was found to have a 1-millimeter-diameter hole last week exploded Sunday, sending mud and debris across Interstate Highway 280 west of Palo Alto.
No one was injured during the 3:30 p.m. incident. The highway was closed for several hours while the California Highway Patrol and firefighters cleaned up the mess.
For the latest on this story, go here.
PG&E said Friday that a small hole was discovered in the pipe segment during hydrostatic pressure testing, which fills the line with water to identify weak seams or holes. On Sunday, PG&E Vice President for Gas Engineering and Operations Kirk Johnson confirmed that a 2-foot-wide section of pipe burst when workers were sending water through it at pressure levels far higher than would normally be allowed.
The utility company has been testing hundreds of miles of pipeline since a 30-inch-diameter pipe exploded in San Bruno in September 2010, killing eight people and destroying a neighborhood. The hole found Friday was identified in Line 132, the same one that ran through San Bruno.
PG&E said Friday’s leak was not a danger to customers. It was found in a 4-mile stretch of 24-inch-diameter seamless pipe that was installed in 1947. Utility officials added that it could take several days to find the exact location of the small hole.
Shortly after Sunday’s explosion, a nearby resident told a California Highway Patrol officer he had heard a “loud hissing noise going on all night and observed a large-diameter pipe spewing mist into the air.”
A 5-by-5-foot crater was found in the hillside where the pipeline failed, according to Woodside Fire Battalion Chief Kevin Butler. The crater is located in an easement running behind homes, and the closest house is about 100 yards away.
Another segment of pipe exploded last month near Bakersfield, during a separate pressure test. No one was injured in that incident.
Wire services contributed to this report.