RICHMOND -- Leaks like the one detected by Chevron refinery operators two hours before Monday's massive fire are not uncommon within oil refineries, with their thousands of miles of pipes, experts said Friday.
In fact, the Richmond facility had three reported leaks in the two months before Monday's fire, and may have had more; plants are not required to report leaks deemed insignificant. Refinery pipes generally have shorter segments and more joints and flanges than, for example, underground natural gas transmission pipelines, creating more opportunity for leaks, one industry expert said -- an inherent risk within the behemoth refineries.
"People like to look at these operations as perfect, like they don't vent or drip a little bit," said Richard Kuprewicz, a pipeline safety consultant with 20 years in the refinery business.
Such leaks, however, can become serious. In Monday's incident, fiberglass insulation surrounding an 8-inch carbon steel pipe in the No. 4 crude processing unit may have hidden a larger leak from operators, or masked a physically weakened pipe, said Contra Costa Hazardous Materials Program director Randy Sawyer.
When employees removed that pipe covering, hot liquid and vapor burst out of the pipe, and as employees evacuated, the liquid and vapor burst into flames, possibly ignited by hot equipment or a running fire truck parked nearby, Sawyer said.
"Why it happened then, I don't know. We don't know if the insulation was holding the pipe together," he said, adding the insulation piece was likely destroyed in the intense blaze.
Chevron spokeswoman Melissa Ritchie said, "We cannot speculate on the cause until a full investigation is conducted."
Investigators expect to get access to the fire site by Monday, Sawyer said.
In the two months before Monday's fire, Chevron reported three leaks within its more than 5,000 miles of pipe at the 2,900-acre Richmond refinery. One of them had been reported just days earlier.
On Aug. 3, the Richmond refinery had a flange leak at a fluid catalytic converter feed hydrotreater, but Chevron said Monday's fire was not related to that. On July 17, four barrels of diesel spilled from a leaky pipe, and on June 19, less than a pint of an unknown liquid spilled into San Pablo Bay at the long wharf. Neither was related to Monday's fire, Sawyer said.
"We want to keep everything in the pipes," Sawyer said. "But it's something that you do have ... And all parts of a refinery handle very combustible chemicals."
Leaks are part of refinery workers' jobs, said Jeff Clark, a field representative for Steelworkers Local 5, which represents about 600 operators and mechanics at the Richmond plant.
"Leaks are not a daily occurrence ... but we probably see them more often than we'd like to see them," he said.
How to respond to a leak depends on each individual circumstance, pipeline consultant Kuprewicz said.
"It's easy for the public to come to the conclusion that if you have a leak you should shut it down, and that's not always the case," he said, saying a shutdown could exacerbate the problem. "I've seen hundreds of leaks that do not justify shutting down ... probably more like thousands."
Modernization or expansion?
Refinery pipes are often heated and cooled, causing expansion and retraction -- one reason why they sit above ground. Maintenance is key, experts say, to ensure integrity.
In 2010, Chevron's $1 billion plan to upgrade part of the refinery was stopped by a lawsuit filed by environmentalists who asserted the oil company was hiding its intent to refine dirtier crude oil. The First District Court of Appeal ruled in April 2010 that the company had failed to adequately analyze how the project would affect air pollution. In May, Chevron submitted a new project application to the city.
"We want a modernization project if it will mean old equipment will be replaced," Richmond Mayor Gayle McLaughlin said. "We've been in discussions with Chevron over the revised hydrogen renewal project.
"(Monday's fire) reminds us as a City Council and community to be strong and regulate Chevron to the highest degree," McLaughlin said.
Chevron said the Richmond Renewal Project would replace older equipment to reduce emissions and create a cleaner and safer refinery.
"With approval from authorities, we are prepared to make additional investments in the refinery that will bring updated technology, improvements to operations, reduce emissions, improve energy efficiency and bring more jobs," Chevron's Ritchie said. "The project will not change the range of crude oil blends historically processed at the refinery."
Staff writer Denis Cuff contributed to this report. Contact Matthias Gafni at 925-952-5026. Follow him at Twitter.com/mgafni.