Martinez Refining Company released a “small amount” of coke dust Saturday afternoon, according to the refinery.
The refinery said on social media that, at approximately 1:15 p.m. Saturday, petroleum coke was being transported within the refinery “when a small amount became airborne for a short period of time. Our trained employees rapidly and safely responded, keeping the petroleum coke on-site, in the immediate vicinity where the material was being moved.”
The refinery said it “promptly issued a Community Warning System Level 1 notification, contacted appropriate agencies, and conducted community monitoring.”
MRC said, based on its community monitoring results, the release was contained on-site without any off-site impacts.
Contra Costa Health said on social media they were notified of the release at 1:18 p.m. and the release had “potential offsite impacts.” It also said it was sending its hazmat team to assess any community impact.
Coke dust is a black, sooty substance created during the petroleum refining process. There have been a handful of accidental coke dust releases since the refinery’s large accidental release of 20-24 tons of spent catalyst on Thanksgiving 2022.
The incident is being investigated by an independent panel appointed by the county board of supervisors as well as a separate investigation by the Contra Costa County District Attorney’s Office.
MRC said on social media Saturday “We apologize for any concern this may have caused the community. As always, we have a community inquiry phone number you can call at (925) 313-3777 or (925) 313-3601 during off work hours.”