ConocoPhillips spokesman Mark Hughes said that refinery personnel have to conduct a thorough inspection of all the equipment at the facility before bringing it back online.
"It's not like a light switch that you can just turn on and off," he said.
The problem started at about 10:45 a.m. Friday when the refinery's third-party hydrogen provider experienced an equipment failure, which resulted in a loss of hydrogen to the refinery, Hughes said.
The loss of hydrogen in turn caused the refinery's steam power plant to shut down. Without steam, the refinery couldn't operate and personnel had to begin shutting down the entire plant, Hughes said.
In order to shut down the refinery, personnel had to use the flare to burn off excess fuel, Hughes said.
Paul Andrews, a hazardous materials specialist with the Contra Costa County Hazardous Materials Program, said that because there was no steam to add to the material being sent to the flare, the flare was creating a lot of smoke and potentially releasing un-combusted material into the air.
The health department and refinery officials issued a Level 2 warning for Crockett and Rodeo, which means that some off-site impact was expected. They also notified Solano County health officials because the wind was potentially blowing material over toward Benicia, Andrews said.
County hazardous materials teams and personnel from the refinery walked the communities throughout the incident but didn't detect any elevated levels of hydrocarbons or sulfur dioxide, Andrews said.
Air samples were collected and sent to the Bay Area Air Quality Management District for analysis. Results from the analysis were not yet available today, Andrews said.
The health department did not receive any reports of people experiencing adverse affects from the release, Andrews said. Hughes said no injuries were reported at the refinery.
The refinery now has to submit two reports to the county on the incident, a 72-hour report that will include the initial analysis of the incident and a more thorough 30-day report that will include a root cause analysis, Andrews said.
Those reports will also include information about how much material was released.
The air district will also be conducting an investigation into the cause of the problem and will likely fine the refinery for the release, air district board member Mark Ross said.
The refinery is located at 1380 San Pablo Ave. in Rodeo.