Mercury Scare Hits Riverside County as Orange County Bills GKN Aerospace $4 Million for May Chemical Evacuation

Mercury Reports Send Hazmat Teams Scrambling in Riverside County

Cal Fire and Riverside County Fire Department crews responded Saturday to reports of mercury at multiple locations, starting with a call around 11:24 a.m. to the 24000 block of Magnolia Street in Wildomar, according to the New York Post.

The Riverside County Hazardous Materials Team and county environmental health officials joined the response to figure out whether the mercury reports were isolated incidents or connected, the Post reported.

Mercury is a neurotoxin that can poison the body through vapor inhalation or direct contact. Officials told the Post there was no ongoing threat to residents and no evacuations were ordered. Authorities have not said how the mercury was discovered, how many locations were involved, or whether the reports are connected. The investigation is continuing.

The Bigger Bill: GKN Aerospace Owes Orange County $4 Million, County Says

While Riverside County deals with a contained mercury scare, Orange County is in a financial fight over a much larger hazmat disaster from earlier this year.

County Counsel Leon Page sent GKN Aerospace Transparency Systems Inc. a letter Friday demanding $4,071,305 to cover resource deployment and operational costs from the May crisis at the company's Garden Grove plant, according to MyNewsLA. That figure includes $500,000 spent helping evacuees with expenses, but does not include the $2.8 million the Orange County Fire Authority spent responding, county officials said.

The emergency began May 21, when a cooling system failure on a 34,000-gallon storage tank triggered a chemical reaction in neutralized methyl methacrylate, or MMA, a toxic and highly flammable liquid used to make acrylic plastics, MyNewsLA reported. Roughly 40,000 people in Garden Grove, all of Stanton, and nearby communities were forced out of their homes over Memorial Day weekend while crews worked to stop the tank from exploding or leaking. A crack in the tank eventually relieved the pressure and eliminated the immediate danger.

Orange County Supervisor Janet Nguyen didn't mince words. "The blame for this disaster lies solely with GKN and the county should not be bearing the brunt of these expenses," she said, according to MyNewsLA. "We need reimbursement."

Page's letter argues this wasn't a freak accident. GKN has "a well-documented history of regulatory violations at the site dating back over a decade," including multiple Cal/OSHA citations and a 2021 settlement in which the company paid $909,935 to the South Coast Air Quality Management District over emissions record violations and unpermitted equipment, without admitting liability, according to MyNewsLA and CalMatters reporting republished by Times of San Diego.

The county says it's entitled to full restitution under CERCLA, the federal Superfund law, and California's Hazardous Substance Account Act. GKN did not respond to a request for comment on the letter, MyNewsLA reported.

GKN has already made some financial gestures toward the community. The company donated $3 million to the United Way of Orange County's Community Resilience Fund for evacuees and another $1 million for broader community initiatives, MyNewsLA reported. At a June Garden Grove City Council meeting, GKN Aerospace Senior Vice President Steve Carlin apologized on the company's behalf: "On behalf of GKN and the Garden Grove plant I want to say I'm sorry this event occurred."

Conflicting Information During the Crisis

The response wasn't clean. Patch reported that evacuation orders were issued Thursday, May 21, then lifted that night when crews believed they'd made progress, only to be reinstated and expanded Friday morning "due to changing conditions," according to OCFA. By Friday, officials had created a one-mile buffer zone around the plant.

Orange County Health Officer Dr. Regina Chinsio-Kwong told residents during a briefing that MMA is "very toxic" but that data on human exposure effects is limited, relying partly on animal studies, Patch reported. She said short-term exposure can cause lung and nasal irritation, nausea and dizziness, while high-level exposure risks severe respiratory distress requiring hospitalization.

The messaging got murkier after the fact. Chinsio-Kwong told residents at one briefing there had been no leak and no contamination, according to CalMatters reporting republished by Times of San Diego. Days later, county health officials walked that statement back. Early reports had characterized the incident as a leak in the first place, according to the same CalMatters account.

Residents are entitled to be skeptical of such contradictions. If officials tell you it's safe one week and reverse themselves the next, treating the reassurance as gospel isn't unreasonable caution, it's just trusting the last thing you were told. Boyle Heights resident Manuel Valle, an 84-year-old who handed out N95 masks during an unrelated ammonia-related warehouse fire covered in the same CalMatters piece, put it bluntly: "This is a state emergency. Treat it like a state emergency."

What's Unresolved

GKN hasn't responded publicly to the county's $4 million demand. Whether the company pays voluntarily, negotiates, or forces Orange County into litigation under CERCLA and the Hazardous Substance Account Act remains an open question. Meanwhile in Riverside County, investigators still haven't disclosed how the mercury was found or whether Saturday's reports across multiple locations are related incidents or coincidence.