Nearly 4,000 people were given the all clear Thursday afternoon to return to their homes in Northern California following a grass fire that threatened a natural gas pipeline about 30 miles northeast of Oakland.
The California Public Utilities Commission is investigating the incident in an underground utility vault housing part of the 12-inch diameter pipeline run by Chevron Corp. that runs through the East Bay.
Chevron crews purged gas from the pipeline after a fire erupted Wednesday night, forcing residents to evacuate from nearly 1,400 homes in the Bay Point and Pittsburg areas, according to the Contra Costa County Fire Protection District (FPD). No one was injured in the incident.
Chevron Pipe Line Co. was notified of a fire, apparently caused by a Pacific Gas and Electric Co. (PG&E) power line falling.
PG&E received a report of an equipment failure Wednesday night, which indicated wires were down in the area. A utility spokesperson said birds may have come in contact with the power lines, causing them to fall and ignite, sparking the initial grass fire. Another grass fire near the vault erupted about an hour after the first fire was extinguished.
The pipeline’s pressure then was reduced to 25 pounds/square inch (psi) from 480 psi in a “controlled and safe manner,” according to FPD assistant chief Terence Carey.
Chevron and FPD personnel entered the vault Thursday afternoon to ensure no gas had leaked, Carey said. Chevron personnel planned to remain on the scene for a few days to make repairs.