Update on Activities to Reduce Odor Issues from Castaic and Sylmar Landfills

In 2023, South Coast AQMD began receiving increased complaints about odor issues from two local landfills, Chiquita Canyon Landfill (CCL) in Castaic and Sunshine Canyon Landfill (SCL) in Sylmar. South Coast AQMD inspectors, engineers and legal staff are working hard to help resolve odors impacting the surrounding communities.

In April, South Coast AQMD received an increase in odor complaints that inspectors traced back to the Chiquita Canyon Landfill. It has since been determined that a subterranean chemical reaction causing elevated temperatures beneath the surface of the landfill is increasing odors at the landfill.

The landfill undertook actions to address the odor issues, including installation of new flare equipment, which contributed to a brief decline in odor complaints. Additionally, in September 2023, the South Coast AQMD Hearing Board approved an Order for Abatement requiring CCL to take a series of actions to reduce odors from the landfill. During a recent on-site inspection, however, South Coast AQMD inspectors observed leachate seeping out of the ground and out of gas collection wells at the landfill, which can contribute to increased odors. The investigation revealed that the facility’s leachate collection and storage system was malfunctioning. A status hearing is expected to be held in front of the Hearing Board on January 16, 2024.

Since April, South Coast AQMD has responded to over 6,000 odor complaints and conducted numerous on-site inspections, including a joint multiagency inspection in November, and is partnering with LA County Public Health, County Fire Health Hazmat, County Public Works, CARB, U.S. EPA, the Los Angeles Regional Water Quality Control Board, and CalRecycle for solutions.

At Sunshine Canyon odor complaints started increasing in January due to the record-breaking rains. The landfill took steps to reduce odors and complaints declined. However, new rainfall from tropical storm Hilary in August impeded SCLs prior actions and complaints increased again.

In cooperation with South Coast AQMD’s requests for additional steps to reduce odors, the facility has undertaken steps to improve landfill gas collection. These steps include installation of new vertical wells, additional horizontal collectors, new pumps in new and existing wells, and developing ways to deliver waste during less sensitive trash odor hours. It has also developed a task force to study ways to reduce the odors of loads coming from transfer stations. South Coast AQMD is in ongoing negotiations to have SCL take additional steps to reduce the odors, and continues to work with the city and county, law enforcement agencies, and Los Angeles County Public Health to address the issues.

The public is encouraged to report air quality problems to 1-800-CUT-SMOG or via South Coast AQMD’s online complaint report form for investigation.

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