Chevron says it doesn't know yet when natural gas will start flowing again through a 24-mile-long pipeline that was shut down this week after a fire in eastern Contra Costa County threatened the line and forced thousands of people from their homes.
The 12-inch high-pressure pipeline carries natural gas from Pittsburg to the oil company's Richmond refinery. It runs through an underground utility vault that caught fire late Wednesday.
The California Public Utilities Commission and the Contra Costa County Fire Protection District are investigating the incident, which not only prompted residential evacuations but also shut down nearby rail lines and closed an elementary school. About a dozen public agencies responded.
"It is still too early to say when the pipeline will restart," said Braden Reddall, a Chevron spokesman.
Teams from Chevron will inspect the line, test its integrity and assess damage, Reddall said.
"We will not restart the line until we are fully confident that it is safe," he said.
The Chevron line is fueled by a PG&E-operated pipeline system that carries natural gas from wells on Union Island in the Sacramento-San Joaquin Delta.
The Chevron pipeline takes that natural gas from an area east of Highlands Ranch Park in Pittsburg to the Chevron refinery. It's one of a number of natural gas lines that stretch through Contra Costa County and wider parts of the Bay Area.
It's unclear what impact, if any, the pipeline's shutdown will have on refinery operations or gasoline prices.
If the pipeline is out of operation for an extended period, the region's gas supply could be affected, according to professor Eric Smith of Tulane University's Energy Institute.
"Local prices for gasoline could be affected if the repairs and red tape stretch beyond two weeks because gasoline will need to be brought in from outside the area," Smith said in an email.
"I really don't see any case where the refinery would shut down completely," Smith said in an email. "Although the loss of natural gas supply would depress the overall profitability of the site, no matter what they do."
Natural gas is most likely used to power heaters used in the refinery's operations, Smith said. It's not a fuel, like crude oil, that would be refined into gasoline.
Chevron's Reddall said the company does not anticipate any impact to refinery operations because of the fire.
The approximately 4,000 Bay Point and Pittsburg residents forced from their homes because of the fire late Wednesday night were allowed to return Thursday afternoon after the site was deemed safe.
That allowed Contra Costa County fire officials to get a better look at the vault and launch their investigation into the cause of the blaze and its point of origin, according to Steve Hill, a fire district spokesman.
A PG&E representative says the utility believes at least two birds knocked down power lines, causing a grass fire near the underground facility. It's unclear, though, if that blaze ignited the fire inside the vault.