SAN FRANCISCO (AP) -- Federal investigators on Monday called on California to strengthen oversight of refineries after a probe into the cause of an intense fire at Chevron Corp.'s Richmond refinery found numerous company and regulatory lapses that, if reversed, could have averted the accident.
The U.S. Chemical Safety Board released an interim investigative report of the Aug. 6 refinery fire, which was caused by a corroded pipe that failed and released a massive vapor cloud that engulfed 19 employees. While it was a close call, none were seriously injured.
Still, the resulting black plume of smoke drifted over nearby neighborhoods and sent 15,000 residents into hospitals seeking treatment for breathing problems and eye irritation, 20 of whom were admitted for treatment, the CSB said.
The board's investigation found that Chevron's own technical staff made at least six recommendations since 2002 to increase inspections or upgrade equipment in the crude unit containing the 1970s-era pipe that eventually failed.
Still, as Chevron's own investigation of the incident found, the company neglected its own internal recommendations and failed to replace the pipe.
"Chevron failed to replace critical sections of piping at the crude oil unit over a 10-year period," Rafael Moure-Eraso, chairman of the chemical board, said. "The company was aware of sulfur corrosion ... and risk of catastrophic failure."
Chevron said it is reviewing the CSB's report and working closely with the agency to build more transparency into its safety culture.
"The refinery has also begun to implement an enhanced process for regular damage mechanism reviews for each unit and piping circuit to improve the evaluation of known damage mechanisms, the potential consequences of a failure, and the safeguards necessary to mitigate failures and other potential risks," Melissa Ritchie, a Chevron spokesperson, said in an emailed statement.
The CSB's report says Chevron and the entire industry knew that the increased use of crude oils with higher sulfur content would cause higher rates of corrosion in their old pipes.
But neither state nor federal regulations required the company to replace the old pipes with more sulfur-resistant materials.
California and federal governments should create new regulations that require companies to use the "safest feasible technologies and materials," the investigators said.
"Make no mistake: the ultimate issue here is not corrosion but how to make effective corporate decisions, and regulators need effective tools and resources to encourage companies to make the right choices," Moure-Eraso said. He said the state's moves could help strengthen safety at the nation's 144 refineries.
The board is also recommended that the California Division of Occupational Safety and Health, or Cal/OSHA, hire more technical staff who can help the agency do a better job at refineries.
Cal/OSHA issued 25 citations carrying nearly $1 million in fines related to the incident and other issues at the Richmond refinery.
Some state lawmakers have supported the CSB's call for more intense regulation.
"While Chevron is ultimately responsible for the safety of its workers and the surrounding community, the Chemical Safety Board correctly points out that our existing regulations were not adequate to ensure safe operations," Assemblymember Nancy Skinner, D-Berkeley, said in a statement.
"We need to ensure that OSHA has adequate funding and staffing, as well as to enact more precise safeguards so that California's chemical and refinery facilities are not a disaster waiting to happen."