People with respiratory conditions were advised to avoid the area on San Francisco Bay in northern Contra Costa County shortly after noon while thick smoke billowed from the Tesoro Golden Eagle Refinery on Solano Way in unincorporated Martinez, according to the San Francisco Chronicle newspaper.
Refinery spokeswoman Patty Deutsche told the newspaper that the thick smoke was caused by a failure of the facility’s main steam generation unit.
“Steam is what powers the entire refinery,” Deutsche said.
“If steam is all of a sudden reduced, the oil can thicken up and build up pressure — it can be dangerous to the entire process,” she said.
Sure enough, the lack of steam caused equipment to flare up and smoke as hydrocarbons that would normally be consumed in the refining cycle caught fire.
At around 12:20 p.m., the Contra Costa health department and Bay Area Air Quality Management District tested the air around the refinery and said no harmful emissions had been released, the newspaper said.
Nevertheless, county health officials advised those with respiratory conditions to avoid the area, health department spokeswoman Victoria Balladares told the newspaper.
Health officials declared a Level 2 incident, advising people in the community that a “level 2 incident” had been called by health officials and that people in the communities of Martinez, Avon, Pacheco, North Concord and Clyde with preexisting respiratory problems could experience breathing difficulties.
Contra Costa also sent a hazardous materials team to the refinery to assess the health risk, Balladares said.
After more than an hour, the steam generator was restarted and resumed normal operations.
The health advisory was lifted just before 2 p.m., Deutsche said.
Refinery officials have opened an investigation into the incident, the newspaper said.
“There were no injuries as a result of this event,” Deutsche said in a written statement.
“We do not expect any adverse health effects,” she said.
The incident was far from the first at the refinery since Tesoro purchased it from Tosco Corp. in 2000.
In August, Tesoro Corp. settled a $4 million lawsuit that claiming the refinery illegally discharged refinery byproducts in area sewer and water-treatment facilities.
The refinery was the scene of a tragic accident in 1999 in which four workers were burned to death while trying to replace a leaking oil pipe.
Tosco merged with Phillips Petroleum, now part of Conoco-Phillips, in 2001.