MARTINEZ -- A shelter-in-place order has been lifted tonight after a power failure in a PG&E substation at the Tesoro Golden Eagle Refinery triggered a huge flare-up at the refinery that sent choking smoke drifting eastward.
"It is a major flaring event," said Lisa Fasano, a spokeswoman for the Bay Area Air Quality Management District. "It should not be impacting the community, but as a precaution the shelter-in-place was called."
All five of the refinery's flares began burning gases and shooting flames after the power failed just after 4 p.m. Wednesday. Flares act essentially as safety valves to burn gases that would otherwise escape in more poisonous forms during a refinery upset.
The flares released thick black smoke
A county hazardous materials specialist at the scene said Wednesday evening that the county had received no complaints of health problems.
"Not complaints -- a lot of questions," said Paul Andrews.
The shelter-in-place order was lifted shortly before 7:30 p.m., but a health advisory remains in effect for the areas of Avon, Clyde, all of Concord, Port Chicago, and the neighborhood east of Highway 242, south of Highway 4 and north of Olivera Road, according to a news release from the Contra Costa County Health Services Department.
People with asthma or similar conditions are advised to remain indoors if possible.
The power outage prompted an emergency shutdown of the refinery, which caused gases to be routed to the flares. Otherwise, there was a risk of explosion if pressure built up too high due to an inability to move chemicals around within the refinery.
"This was an emergency shutdown because they couldn't run the pumps and compressors that they need," Andrews said.
Shelter-in-place orders were issued for Clyde, North Concord and East Martinez, according to the Martinez Police Department. Additionally, residents in Bay Point and other eastern communities downwind of the plant were cautioned to stay indoors, Contra Costa County Hazardous Materials Program Director Randy Sawyer said.
The Contra Costa Sheriff's Office said the flaring could affect some people. They advised anyone experiencing eye, skin, nose or throat irritation to go indoors and rinse any irritated area of their body with water.
In an e-mail alert sent via the county's Emergency Digital Information Service, residents were advised to close all windows and doors, and to turn off heaters, air conditioners and fans. Health officials also advised closing fireplace dampers and vents and covering cracks around doors and windows with tape or damp towels.
The Contra Costa Hazardous Materials program received notification of the flare-up at 4:12 p.m., Sawyer said. It was traced to a power outage in a refinery substation that also affected much of downtown Concord.
About 17,000 customers in Concord initially lost power, a Pacific Gas and Electric spokeswoman said. All but 1,000 of those affected had power restored by 5:20 p.m. The cause of the outage was being investigated.
The outage was affecting traffic signals in Concord. Drivers were being urged to use caution and to treat intersections with non-functioning signals as stop signs.
Sawyer said crews had begun to depressurize the refinery, a process that was expected to be completed quickly because there was no damage to the plant.
"It will take a while but (the flares) will go down," Sawyer said. "When they shut down the refinery the flare will go down."
Fasano said air district inspectors were on the scene with county hazardous materials teams.
Unexpected and sudden refinery outages can fuel a spike in gasoline prices, according to state and federal studies.
In May 2006, gasoline prices in California jumped to what was then an all-time high of $3.33 a gallon. Multiple factors contributed to the surge in pump costs, a state Energy Commission report released in August 2006 determined.
"Several unusual factors," the energy agency reported, "tightened supply and contributed to the gasoline price spike." The factors included "refinery problems and unplanned outages," the commission stated.
It was not immediately known if Wednesday's incident would result in fuel shortages.
In Martinez, the county's Community Awareness and Emergency Response network was activated around 5:10 p.m. Emergency sirens were sounded, and an automated telephone tree began calling residents to inform them of the shelter-in-place order.
The situation created severe traffic congestion and confusion for people leaving work who were startled by the sirens.
Several county workers leaving downtown Martinez offices for the day when the alarms began to sound worried about traffic on Highway 4 and were trying to find information about the situation.
Staff writers George Avalos and Malaika Fraley contributed to this story.