On October 6, Contra Costa Health (CCH) dispatched a hazardous materials team to the Martinez Refining Company (MRC), following a self-reported release of petroleum coke dust in Oakland. MRC alerted the Contra Costa County's Community Warning System at 10:31 a.m., with CCH's inspection revealing no immediate public health threat in the affected vicinity.

Maintenance work was identified by MRC as the source of the incident and temporarily put on pause to resolve the issue. CCH has since requested a 72-hour report on the matter from MRC, slated for future publication on the county's hazardous materials website.

There was a confirmation given by MRC, to CCH, that no additional maintenance work would take place on Friday. A different strategy will be used to finish the remaining work, a development reported in the Contra Costa Health press release. Scheduled community activities, including the Alhambra High School homecoming parade, can continue as planned.

The ongoing investigation has stoked concern among local residents. However, through quick response and efficient collaboration between parties, county authorities have managed to minimize potential risks and ensure the safety of the individuals in close proximity to the facility.