California Attorney General and the Department of Toxic Substances Control sued Waste Connections and the other owners and operators of the Chiquita Canyon Landfill on Oct. 27, accusing them of repeatedly mishandling hazardous waste produced by an underground reaction at the Los Angeles County site.
Chiquita Canyon is a 639-acre landfill in the Santa Clarita Valley that opened in 1972. It stopped accepting waste on Jan. 1, 2025, after it failed to obtain a permit from the Los Angeles Regional Water Quality Control Board, according to the attorney general's office.
The subsurface elevated temperature event began in May 2022 and has spread from 20 acres to at least 90 acres, the office said. Temperatures underground have topped 212 degrees Fahrenheit and reached as high as 260 degrees in places. The reaction releases odors and toxic fumes and produces millions of gallons of leachate, the contaminated liquid that must be pumped out and disposed of as hazardous waste. Tests have found benzene in the leachate and, at times, methyl ethyl ketone.
The lawsuit cites a Nov. 14, 2025, spill of 8,000 gallons of hazardous leachate into the landfill's East Basin, a stormwater sedimentation basin that is not permitted to hold leachate. December rain overtopped the basin's weir, and on Dec. 29 and 30, 2025, stormwater mixed with leachate flowed into Castaic Creek, which drains to the Santa Clara River, the office said.
Val Verde, the closest neighborhood, sits about 1,000 feet northwest of the developed landfill. Halsey Canyon, Halsey Hills, North Bluffs, Live Oak and Williams Ranch are also nearby, along with two preschools, four elementary schools, two middle schools and two high schools, according to the release.
DTSC's claims fall under the state Hazardous Waste Control Law. The attorney general added a claim under Government Code section 12607 to protect the state's air, water and soil, and an unfair competition claim under Business and Professions Code section 17200. The suit seeks civil penalties, disgorgement, an injunction and an abatement fund to address the pollution. DTSC said the complaint lists a dozen causes of action, including failing to minimize the possibility of unplanned hazardous waste spills, unlawful storage of hazardous waste and failing to give accurate information about hazardous waste transport, and asks for civil penalties of $2,500 to $70,000 per violation.
DTSC said it has issued six separate summaries of violations for hazardous leachate releases from 2024 through 2026. The South Coast Air Quality Management District has issued more than 500 violations for air contaminant discharges, and the U.S. EPA has ordered Waste Connections to expand leachate management, stabilize the landfill's western slope and improve air emission controls, according to DTSC.
“We cannot allow the California dream to be smothered by the repeated releases of hazardous waste at the Chiquita Canyon Landfill — we must act,” Bonta said. DTSC Director Katherine Butler said Waste Connections “must manage hazardous waste safely and in full compliance with the law, clean up existing contamination and prevent future harm.”
Assemblymember said families near the landfill “have endured dangerous conditions, toxic gasses, and serious impacts to their health and safety” for years.
The case adds to lawsuits already filed by Los Angeles County and the South Coast Air Quality Management District, and to individual and class-action suits by residents. A multi-agency team including the U.S. EPA, CalEPA, the regional water board, CalRecycle, DTSC and the air district has worked on the landfill since November 2023. The attorney general's release did not include a response from Waste Connections.
State
Rob Bonta
Attorney General · Democrat
Named 2 times in this story.
Portrait: Official portrait
State
Pilar Schiavo
State Assembly Member · Democrat
Named once in this story.
Portrait: Official portrait
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