The report concluded that a pipe ruptured due to severe sulfidation corrosion and there was a very low concentration of corrosion-inhibiting silicon in the ruptured pipe.
Two separate water mains broke Tuesday morning in Redwood City, flooding two homes and damaging an intersection, a city water department supervisor said.
San Francisco Public Utilities Commission crews were at the scene of a water main break in the city’s Sunset District Monday afternoon, a utility spokeswoman said.
Chevron Corp. reportedly considered replacing a corroded Richmond refinery pipe nearly a year ago but decided it was good for another five years of service.
Records show utility crews replaced five miles of aging gas pipes under a San Bruno neighborhood less than two decades ago but stopped just short of a segment that ruptured and exploded last year.
The head of the National Transportation Safety Board said Pacific Gas & Electric’s record-keeping blunders leading up to the San Bruno natural gas pipeline explosion demonstrates a need for stepped up industry safety.
Construction on a new water pipeline through Fremont is expected to affect commuters for the next couple of months. Crews began work Tuesday morning on the pipeline, starting near Paseo Padre Parkway at Grimmer Boulevard.