Federal Agency Probes Marathon’s Martinez Refinery After Two Large Fires Last Month

“Our Biofuels Production Monitor captured this fire just ahead of the planned start of its last renewable diesel unit,” the company said in a post on X, the platform formerly known as Twitter.

During that fire, Jerome Serrano sustained third-degree burns to more than 80% of his body, according to a union official. Serrano has undergone at least two surgeries at UC Davis Medical Center in Sacramento, and family members have been told he has a 10% chance of survival, said Tracy Scott, president of the United Steelworkers Local 5.

“The family is pretty overwhelmed,” Scott said.

The fire in which Serrano was injured followed a blaze on Nov. 11, according to a preliminary report that the company filed with Contra Costa County officials on Wednesday,

Marathon officials have described both fires as facility-wide emergencies. The incidents occurred in a process unit part of the plant’s conversion into a biofuel refinery.

The Nov. 19 fire was more severe than the Nov. 11 episode. In addition to Serrano’s injuries, more than a dozen workers were forced to evacuate in the minutes after the fire erupted. The incident led to the release of more than 200,000 pounds of renewable diesel fuel, according to a separate preliminary report by Marathon.

The smoke that drifted out of the refinery prompted an hours-long public health advisory from Contra Costa County officials. The episode has now led to four separate investigations — by state workplace regulators, the local air district, Marathon itself, and now, the federal chemical safety board.

Marathon managers told union leaders that the first fire, on Nov. 11, occurred during a failed start-up of refinery operations, according to the USW’s Scott. He says the second fire, which also took place during a start-up, was in a different part of the same unit.

The fires come months after Marathon began converting its Martinez facility into a biofuel refinery. Like the Phillips 66 refinery in Rodeo, Marathon has shifted away from crude oil and begun processing vegetable oil and animal fats into biofuels.

Scott says union leaders and workers at Marathon have voiced concerns to the company about training and staffing at the refinery as it transitions. He says employees have told managers the refinery’s training program is deficient, that new workers were pressured to learn the controls too quickly, and that the facility is understaffed.

“If nothing changes, we will certainly experience this type of incident again,” Scott said.

Marathon pushed back on that criticism.

“Our training and staffing levels are based on industry standard practices and are regularly evaluated for effectiveness, quality and other measures,” the company said in an emailed statement Friday morning.

“Our facility has a comprehensive training plan that requires all operations personnel to demonstrate proficiency in their roles before becoming qualified to work, including knowledge, skill and capability related to their specific unit,” the statement reads.

Some environmental groups have sued Contra Costa County over the Marathon and Phillips 66 conversions, arguing that the county’s review of both plans was flawed. Greg Karras, an energy-transition consultant who is not involved in the lawsuit, says the fire is just the latest sign that the conversions are dangerous.

“It was entirely predictable,” Karras told KQED. “They’re repurposing old refining equipment for this new stuff, and they’re finding all sorts of things going wrong.”

But Eric Smith, a Tulane University professor specializing in energy issues, says the refinery changes do not make the facilities more dangerous.

“Operators do need specialized training to avoid accidents, but with proper training, I would opine that they are no more dangerous than the other conventional units,” Smith said in an email.

The blazes come amid recent increased attention on the safety of refineries in the Bay Area.

This week, air regulators issued four notices of violation against Chevron after its Richmond plant had a major flaring incident that sent flames and a large column of smoke into the air, leading dozens of local residents to issue complaints to the local air district.