Friday afternoon flaring at the Martinez Refinery Company sparked concerns among city residents, and the company also reportedly released hazardous materials on Thanksgiving Day without warning.

Large flames and plumes of smoke from the Martinez Refinery Company (MRC) prompted an emergency response late Friday afternoon, which was later canceled because the fire was a part of a deliberate "flare-up" confined to company property, KPIX reported.

CBS News reported that the incident was routine flaring that was conducted to burn off deposits, part of an ongoing special operation. KRON4 reported that there was an equipment issue that led to intermittent flaring.

According to its website, MRC, which was formerly a Shell refinery until it was acquired by New Jersey-based PBF Energy in February 2020, is a “157,000 barrel-per-day, dual-coking refinery … located on an 860-acre site in the City of Martinez, 30 miles northeast of San Francisco, California.”

The City of Martinez issued a statement on Friday that multiple agencies, including Contra Costa Health (CCH), Contra Costa County Sheriff's Office, Contra Costa County Fire Protection District, and the Bay Area Air Quality District (BAAQMD), responded to community reports of “an explosion” and “a significant flaring incident” at the Martinez Refinery. The statement said that MRC reported to city officials that “the flaring event [was] likely due to the failure of a compressor.”

MRC is required by state and county law to notify Contra Costa Health (CCH)  and the county's Community Warning System about chemical discharges within 15 minutes. Friday’s flareup alarmed citizens still reeling from an incident on the evening of Thanksgiving, when MRC released possibly harmful chemicals for 12 hours without warning, according to health officials.

"MRC's failure to follow notification procedure cost us critical time we could have used to warn the public and reduce health risks in the community. It's unacceptable," Deputy Health Director Matt Kaufmann said in a statement at the time.

The day after Thanksgiving, a powdery substance coated many Martinez residents’ cars and community facilities, as KPIX reported. The county subsequently released a statement that upon investigation, MCR accidentally released "spent catalyst." The health department collected samples of the substance, and tests showed that it contained higher-than-normal amounts of heavy metals. The statement said that while it likely posed no immediate health risk to the community, the “most significant health risks were short-term respiratory impacts from breathing in the metals in the hours after the release.”

Image via Wikimedia/JpxG.