RICHMOND (AP) — Structural engineers on Monday deemed the site of a Chevron refinery fire in the San Francisco Bay area hazardous for human entry after looking at the failed pipe that leaked and sent a towering plume of black smoke into the sky.
Federal and state investigators are discussing plans for how to make the Richmond site safe so the faulty pipe can be removed for testing, said Hillary Cohen, a spokeswoman for the U.S. Chemical Safety Board.
"The crude unit is still off-limits because of safety concerns. Probably for another day or two," said Peter Melton, a spokesman for the state division of occupational safety and health, or Cal-OSHA. That agency is also investigating the cause of the blaze.
The Aug. 6 conflagration destroyed an area of the refinery that produces a large amount of the gasoline that satisfies California's clean-air regulations, the toughest in the nation.
The blaze sent thousands of residents to hospitals with complaints of eye irritation and breathing difficulty. The company has set up a claims center to help those seeking compensation from exposure to the smoke.
Other parts of the refinery, which supplies 16 percent of California's daily gas consumption, are still producing fuels. But the refinery's reduced output has sent state gas prices rising higher than normal, analyst said.
The average price for a gallon of regular on Monday in California was $4.07, up from $3.86 last Tuesday.
The small leak in the eight-inch pipe was discovered quickly by Chevron's engineers, a fact that may have helped save their lives, said Randy Sawyer, chief environmental health and hazardous materials officer for Contra Costa County, where the refinery is located.
When the crew removed insulation to inspect the decades-old pipe, the more than a dozen of Chevron's crew were engulfed in a cloud of vapor and narrowly escaped the unit before the fire ignited, investigators from the U.S. Chemical Safety Board said.
"It was good they found the leak early ... the sooner you find the (leak) and ignition point, the less fuel there is to burn at the ignition point," Sawyer said.
Investigators want to learn why Chevron did not replace the old pipe that failed, and suspect corrosion as a likely cause of the leak.
The company had inspected the unit last November and replaced a larger corroded pipe that was connected to the one that failed, federal investigators said.
"Investigators continue to be onsite and we are fully cooperating with them to move this investigation forward," said Melissa Ritchie, a company spokeswoman.
Copyright 2012 The Associated Press.