Air quality officials have ordered the Chiquita Canyon Landfill in Castaic to find ways to reduce the odors that residents have been complaining about for years.
The South Coast Air Quality Management District has been fielding thousands of complaints about odors that an air quality inspector described as a “sour milk rotting,” “sweet rotting fruit,” and “rotten egg." And after a lengthy hearing on Wednesday, the AQMD ordered the landfill's operator, Waste Connections, to mitigate the stench.
Who is affected?
Those living in the cities of Val Verde, Castaic, Live Oak and Hasley Canyon have been inundating the South Coast Air Quality Management District with a barrage of complaints.
According to Laurance Israel, a supervising air quality inspector with AQMD, since May the agency has received more than 2,100 complaints that have resulted in 58 notices of violation against the landfill.
What is causing the stench
The odors are the result of elevated levels of sulfur, specifically dimethyl sulfide and some leachate, a term for water that has passed through solid waste leaching out chemicals. And following the complaints and notices of violation, the AQMD issued an “Order of Abatement” — like a sanction — against the Chiquita Canyon landfill, triggering a hearing.
After eight hours of public testimony and expert analysis at the hearing on Wednesday, the AQMD ordered Chiquita Canyon landfill, run by Waste Connections, to take immediate steps to mitigate the stench. That includes installing an “impermeable” cover over the area that is emitting the excess gas.
However, the AQMD and the landfill do not have "precise answers as to how to end this reaction,” said Kathryn Roberts, an attorney for AQMD. Instead, the AQMD has ordered Chiquita Canyon landfill to form a committee of "subject matter experts” to ultimately propose “a final solution that will end the landfill reaction and the ongoing public nuisance,” Roberts said.
About the rare reaction creating the odor
Robert Dick, a senior vice president at SCS Engineers who will serve on this committee, spoke at Wednesday’s hearing. He said the odors are a result of a rare, adverse reaction in an old area of the landfill.
Typically, microbes eat waste and the waste then decomposes at a slow and steady pace. However, in an elevated temperature landfill — at a temperature of 170 degrees Fahrenheit or higher — microbes can no longer function properly, resulting in the waste being decomposed at a quicker speed releasing large amounts of heat, liquid and landfill gas.
In his testimony, Dick said that while on the committee, he would review gas temperature data, leachate composition data and “a host of other scientific data that'll be provided to me,” to determine the cause of the elevated temperatures.
However, he also made clear that, “we may not arrive at a definitive answer to what was the cause for the heat to initiate in this facility.”
To minimize the release of the odors, Dick would work with the facility on heat collection and liquid collection methods.
The backstory
Residents have long raised a stink about the landfill. The 639-acre landfill opened in 1972 and in 1997, the Val Verde Civic Association reached an agreement with the former owner to close the landfill in 2019, or when it reached 23 million tons of garbage. But when Chiquita Canyon reached that limit in 2016, Los Angeles County officials extended operations by a year.
Then in 2017, the current owners sought a new 30-year permit in 2017. Under this agreement, the landfill could potentially hold 61 million more tons of trash.
And some members of the public speaking about the odors at yesterday’s hearing blamed the ongoing issues on the landfill expansion.
“There's been what I would consider a(n) environmental disaster that we are dealing with, where we cannot open our windows,” said Val Verde resident Cody Clark. “We go outside and we are hit by toxic fumes and gases outside of our house. And we are having health problems every day.”
Other residents complained of coughing, burning eyes, dry throats and aggravated asthma.
What's next
Tasked with understanding the health consequences of the odors is Pablo Sanchez Soria, a toxicologist with CTEH, an environmental consulting firm.
The gas is produced in the body, he said during his testimony, and is a food additive. Exposure to the gas can result in headaches, nausea and vomiting. Sanchez Soria will prepare a report outlining the health risks from acute and long-term exposure to dimethyl sulfide.
The report will be released on Jan. 15, 2024, and include steps public health officials can take.
