The latest problems identified at Chiquita Canyon Landfill are five Class-I violations reported by the state’s Department of Toxic Substances Control, which says the landfill illegally dumped toxic waste at a facility in Gardena after trucking it away from the Castaic landfill, according to an alert the DTSC sent to The Signal Tuesday evening.
The offenses are the most serious classification on the DTSC website, representing “a significant threat to human health or safety or the environment” because of either the relative hazardousness of the waste or the proximity of the population at risk.
According to the DTSC, Chiquita was found to be illegally disposing of hazardous waste — landfill leachate that contained toxic levels of benzene, a carcinogen — at a facility that is not permitted to treat hazardous waste.
The complete investigation report is not expected to be available until April, but a summary of violations issued this week describes how the landfill failed to label as hazardous waste a 4,600-gallon load of toxic leachate pumped from Chiquita Canyon that the landfill operator was trying to dump at a nonhazardous waste facility.
The first two violations refer to the same incident date of Dec. 27, but the language in the violation states “on and/or before Dec. 27,” indicating the issue could have happened prior to the stated violation.
A spokesperson for the Department of Toxic Substances Control was not immediately available to answer questions on Wednesday morning. A Chiquita Canyon Landfill representative did not immediately respond to a comment request sent Tuesday night.
Landfill officials have repeatedly cited the need for more time to address the issue regarding the smell, which has by nearly all accounts only gotten worse over the past year, in terms of the impacts to residents. The landfill has undertaken a number of mitigation measures listed on its website. None of the efforts have reduced the smell for residents yet, which has been reported as far away as West Ranch High School.
The landfill first learned of the problems during a preliminary root-cause analysis in February 2023. Citing historic levels of rain that winter as a contributing factor, officials reported that an older section of the landfill began to decompose at levels that completely overwhelmed the landfill’s systems designed to mitigate smell and containment of leachate, a chemical formed when rain filters through rotting trash and landfill gases at the facility.
The landfill first discovered its leachate-seepage issues in April, which is a separate but related problem to the landfill gas odor. The odors have resulted in more than 7,000 complaints and 100 violations over the last year, according to the most recent count by the South Coast Air Quality Management District.
The seepage was reported to the AQMD in October at an interagency meeting of landfill regulators and not by the landfill, per testimony in front of the South Coast District Hearing Board in January.
By November 2023, one month prior to the DTSC investigation, the landfill was extracting about 1 million gallons of leachate per week, according to the facility’s reports.
According to the DTSC’s investigation, Avalon Environmental Services, a Gardena wastewater treatment facility, collected split samples from the tanker truck carrying leachate from Chiquita Canyon Landfill.
One sample was provided to the L.A. County Fire Department, Health Hazardous Materials Division, and the other was kept by the facility. “These results show the leachate sampled from the truck was in exceedance for benzene, reporting 0.538 mg/L (milligrams per liter). This is above the Toxicity Characteristic Leaching Procedure (TCLP) regulatory limit for benzene of 0.5 mg/L.”
Benzene “is produced by both natural and man-made processes,” according to the National Cancer Institute, which states that crude oil is the main source of benzene produced today. Exposure to benzene increases the risk of developing leukemia and other blood disorders, according to the website.
“Leachate is treated through Avalon’s organic Subcategory C wastewater treatment process, which includes filtration and granular activated carbon adsorption,” is how the DTSC report describes the treatment at the Gardena facility. Once treated, this wastewater is discharged to the Los Angeles County sewer. Avalon is not permitted by DTSC as a treatment, storage, and disposal facility for hazardous waste, according to the agency.
