PBF Energy's (PBF.N) 156,400 barrel-per-day capacity oil refinery in Martinez, California released petroleum coke dust, a byproduct of the refining process, on neighboring communities, Contra Costa Health (CCH) Services and the refiner said on Tuesday.
Significant quantities of fugitive dust from pet coke storage and handling operations present a health risk, according to the U.S. Environmental Protection Agency.
PBF Energy confirmed the release of coke dust in an email response and said it issued a Community Warning System Level 1 notification. "Refinery personnel are conducting offsite monitoring," the company added.
County health officials said they were concerned that the release, which lasted about one minute, was reported by the refiner at around 10:20 a.m. with a nearly two-hour delay.
Samples of the dust on the ground, parked cars and other surfaces in surrounding neighborhoods are being analyzed in a lab with results expected by the end of the week, CCH said.
Petroleum coke is a carbon intensive solid residue left over from coking units in refineries that break down residual oil into more highly valued products.
CCH said people should avoid breathing in material from the refinery or being in close contact with it. CCH also tweeted that its HazMat team was responding to the release.
The Department of Justice is currently investigating the refinery over a November 2022 release of a powdery substance later determined to be spent catalysts.
Contra Costa County officials are also probing the root cause of the November incident, and the county district attorney is pursuing legal action against the refinery for not notifying health officials when the accident happened.
In February, an analysis report by the refiner said the catalyst overflowed after valves to keep pressure rising in the refinery's reactor and regenerator were not adjusted properly.
A county-hired toxicologist TRC said in June that the release did not increase the public health risk of exposure to heavy metals in the soil.
Reporting by Harshit Verma in Bengaluru and Laura Sanicola; Editing by David Gregorio, Stephen Coates and Leslie Adler
