The Bay Area Air Quality Management District has issued four notices of violation to Chevron connected to a flaring episode at its Richmond refinery that occurred Monday.

Three of the violations were for visible emissions and one was for a public nuisance violation, an air district spokesperson said Wednesday.

The district was notified about the flaring at 3:42 p.m. Monday. People across the Bay Area reported heavy smoke and flames coming from at least three smokestacks.

Smoke and flames billow from the Chevron Richmond Refinery on Nov. 27, 2023, during an unplanned flaring event that triggered a Level 1 Community Warning System alert. The Bay Area Air Quality Management District is investigating the incident after receiving more than 100 air quality complaints related to it, the district said. (Image via BAAQMD)

Chevron said a partial power failure caused the flaring, which is typically the burning of excess gases.

The heavy smoke triggered a Community Warning System Level 1 warning issued by Contra Costa County. The warning didn’t require any action and no one was evacuated. The air district said Chevron reported the flaring stopped at 2:03 a.m. Tuesday.

An air district spokesperson said the investigation is ongoing and more violations may be issued.

More information on the case can be found on the air district’s website.