A large amount of black smoke could be seen coming from flares at the Chevron Richmond Refinery on Tuesday afternoon and the Bay Area Air Quality Management District has sent inspectors to investigate the cause.
Chevron refinery officials reported the problem shortly before 3 p.m. to the Governor's Office of Emergency Services, saying some sort of upset at the refinery released an unknown amount of sulfur dioxide and caused smoke to come out of the flares.
The smoke could be seen from miles away and is the latest incident involving the Chevron refinery, which has already had multiple cases of flaring this year and also spilled several hundred gallons of oil at its long wharf in February.
The air district said later Tuesday afternoon that its inspectors are at the scene "working to find the root cause of the smoke in addition to any potential air quality violations."
Get a weekly recap of the latest San Francisco Bay Area housing news. Sign up for NBC Bay Area’s Housing Deconstructed newsletter.