MARTINEZ — Federal agents have started asking questions about the 24 tons of toxic, dusty residue that showered down on neighbors living near the Martinez Refining Company last Thanksgiving.

The Federal Bureau of Investigation and the Department of Justice started assisting the Environmental Protection Agency investigate the November 2022 incident this week, going door-to-door to survey residents about their experience, according to news reports and a news release from a community spokesperson.

For now, the tens of thousands of residents who found a fine, white substance blanketing their cars, porches and plants over the holiday continue to wait for answers about if – or to what extent – the community was poisoned more than six months ago.

Shortly after the incident, the company said on Facebook that the ashy grit was a “non-toxic”, “non-hazardous” and “naturally occurring” catalyst dust expelled from its 860-acre facility, which is located at 3485 Pacheco Blvd. on the city’s northern industrial corridor.

But within a few days, the Contra Costa County Health Department alerted residents that the dust — a byproduct of the gasoline, diesel and jet fuel refined at the facility — actually contained aluminum, barium, chromium and other hazardous metals. Those chemicals are linked to nausea, vomiting, respiratory issues, immune system dysfunction, cancer and even death.

County officials said that the company failed to immediately inform them of the chemical release, which is required by law.

Heidi Taylor, who moved to Martinez with her family in August, said her son and husband first noticed the spent catalyst the day after Thanksgiving, finding an antique dresser that was left outside covered with a chalky, white dust, according to the Los Angeles Times.

Initially thinking the substance was soot from wood burning, Taylor’s son wiped his hand across the top of the furniture, which sent dust into the air.

“That memory is just seared into my brain and it freaks me out,” Taylor told the Los Angeles Times, adding that she also ate homemade applesauce and peppermint tea from the family’s backyard trees and garden. “I understand that may sound a little crazy … but people don’t understand what it’s like to live in this constant fear and anxiety of not knowing what these toxic metals will do.”

The Martinez Refining Company, owned by PBF Energy, is aware of the federal inquiry, but declined to comment on details of the ongoing investigations, according to spokesperson Brandon Matson.

FBI agents and EPA Region 9 staff have been going door to door in the city of Martinez, asking residents for details about the release of metal-laden dust from the Martinez Refining Co. over the Thanksgiving holiday last year.

An FBI spokespeson confirmed Friday that the agents were canvassing residents as part of a joint investigation, but referred all other inquiries to the EPA.

“EPA is communicating with local, state, and federal agencies and does not comment on any ongoing investigations,” said Michael Brogan, a spokesperson for EPA Region 9.

Martinez Refining, located on an 880-acre industrial complex on the northern edge of the city, emitted as much as 24 tons of so-called spent catalyst, a mix of chemicals used to break down crude oil into finished petroleum products like gasoline, according to the local air district.

The fallout left cars, homes and at least one school blanketed in a white powdery substance. Tests determined that the residue contained metals such as aluminum, barium, chromium, nickel, vanadium and zinc.

Martinez Refining did not immediately inform county officials about the chemical release as required by law, according to Contra Costa County Health Services. The local air district and county officials learned after receiving complaints from residents.

The health department later advised community members not to eat foods grown in the soil if their homes were dusted by the spent catalyst.

The entry of federal investigators has stunned Martinez residents who are still awaiting the county-ordered soil testing and investigations by other local agencies.“We kind of expected quiet investigations in the background. But to have the FBI come out, that was never on our radar at all,” said one Martinez resident who spoke with federal investigators and asked to remain anonymous out of fear of retaliation.

The county health department has referred two violations to the Contra Costa County district attorney’s office — one for failure to notify the proper authorities of a hazardous material release and one for illicit discharges into the county stormwater system. Both referrals remain under review.