Around 2:40 p.m., Chevron notified Contra Costa County that flaring was happening at the plant due to an "unplanned upset in one of its systems" causing the release of Sulfur Dioxide.
Chevron officials say this is a "Level 1" incident and no actions by the public are needed.
Contra Costa County officials say they have sent two hazmat teams to monitor the air quality. They say the wind is blowing to the east and have notified Solano County that they will be impacted.
Officials say that Chevron has notified them that the flaring has significantly subsided.