Chiquita Canyon Landfill gets over 20,000 odor complaints — and new orders to fix them

The beleaguered Chiquita Canyon Landfill in Castaic will have to take additional steps to mitigate the odors that have plagued nearby residents for years.

On Tuesday, the South Coast Air Quality Management District’s hearing board issued an abatement order that includes more than two dozen conditions aimed at improving leachate collection, mitigating odors, and requiring additional air monitoring.

The backstory

Smells from the 639-acre landfill, which opened in 1972, have bothered the community for a long time.

The issue stems from a rare reaction in the landfill. Temperatures are too high for the microbes that eat waste to function properly, which is causing it to decompose faster, releasing large amounts of heat, liquid, and landfill gas to the surrounding community.

The landfill itself is growing, too. Under an agreement with a previous owner, the landfill should have shut down when it reached 23 million tons of garbage in 2016.

But its current owner, Waste Connections, obtained a 30-year permit in 2017 where it could potentially hold 61 million more tons of trash.

AQMD has received more than 20,000 complaints from residents, ranging from a rotten egg stench to burning eyes. Roughly 14,000 of those complaints are from 2024 alone.

What does the order do?

This latest move comes a year after AQMD issued the original abatement order and an EPA order to fix the smells. According to the board, “the landfill has shown no meaningful decrease in nuisance-level odors in the impacted communities.”

The order includes directions to limit the size of excavation (a key reason for the smells), apply odor neutralizers, and provide notice to the community about certain actions. The order also stipulates that excavation activities will have to be reduced if an odor nuisance violation is issued.

Waste Connections is currently excavating the west slope of the landfill as part of efforts to mitigate the elevated landfill temperature.

Robert Dick, a senior vice president at SCS Engineers, is one of the members of a committee tasked with finding a solution to the reaction. In his testimony Tuesday, he described the landfill as being successful at reducing the impacts off-site that are attributed to the reaction.

But when asked by the board why methane rates remain high in the community, Dick said they don’t necessarily see that all methane being detected at community stations can be attributed to landfill methane emissions.

“We do have evidence that there’s less fugitives being emitted,” Dick said.

What’s next?

According to Dick, it’s reasonable to expect that containing the reaction more down the road will lead to less of a foul smell.

But for now, the Chiquita Canyon Landfill will have to comply with the order. It prompts actions on nearly all of AQMD’s latest concerns, except for two related to trash.

Both parties will return to seek a resolution there in November.