The closure of Clover Flat Landfill, the mountaintop dump above Calistoga that has spent years fending off fire, leaks, and contamination problems, is moving more slowly than originally announced, and nobody at recent public meetings could say exactly when it will finally shut its gates.
Carlos Ramirez told the Upper Valley Waste Management Agency board that the closure timeline has been pushed back, according to The Napa Valley Register. The board, which met in the Yountville Town Council chamber, includes representatives from Napa County, the Town of Yountville, and the Cities of St. Helena and Calistoga — the same joint powers authority established in 1992 to oversee regional waste franchises. Waste hauled from Calistoga, St. Helena, Yountville, and nearby rural areas all ends up at the 78-acre site, which has operated since 1963, though Napa and American Canyon do not send their trash there.
Owner Waste Connections announced in September 2024 that it would close the landfill for economic reasons, and at the time, the company said it could submit a closure plan to regulators in 2025, with cap work potentially beginning as soon as 2027. As of Monday, though, Waste Connections had not submitted a closure plan, per the same Register account. Ashley Currie explained that under state rules, a closure plan is submitted two years before the anticipated final amount of waste is received — a requirement rooted in Title 27 of the California Code of Regulations, which mandates that landfill operators file final closure and post-closure maintenance plans with CalRecycle and regional water boards well ahead of shutdown.
Why the Paperwork Is Holding Things Up
The holdup, according to Ramirez, traces back to CalRecycle instructing Waste Connections to update a technical document — essentially the operating handbook for the landfill, as Ramirez described it. That technical-document update has slowed the closure work, and the new timeline remained unclear at the meetings. Neither the state nor Napa County has sought to force the landfill closed, the Register reported, even as the delay drags on.
Waste Connections has said it could bid the closure project out in 2026 and plans to ship Clover Flat's waste stream to the Potrero Hills Landfill in Solano County instead. That facility includes an 8-megawatt landfill gas-to-energy plant that generates renewable electricity for Pacific Gas & Electric, according to Biomass Magazine — a modern contrast to the aging mountaintop site above Calistoga that Waste Connections bought in 2023 from the Pestoni family, who had run the local hauling and disposal business since 1959.
A History of Leaks, Fires and Fines
Clover Flat's environmental record is long and troubled. In 2019, Napa County said chemically and metal-contaminated water ran from the landfill into Dutch Henry Creek, which flows into the Napa River — an incident county officials have since put at an estimated 40,000 gallons of leachate. That spill led the landfill's owners to agree to pay $6.6 million for environmental restoration work in 2025, a settlement Hoodline previously reported was reached with the Napa County District Attorney's office. Separately, the landfill's owners agreed to pay $100,000 in fines to settle a county civil lawsuit, and the San Francisco Bay Regional Water Quality Control Board levied a $619,000 fine over landfill leaks.
The site has also weathered fire trouble for years. During the 2020 Glass Fire, the landfill suffered severe structural damage that completely incinerated its erosion, sedimentation, and stormwater control measures, according to background reporting from North Bay Bohemian. The landfill experienced a string of fires in 2018, and local fire chief records reviewed in 2024 showed at least 13 self-ignited fires at the site between 2013 and 2020, per Wine-Searcher. Napa County inspectors found the landfill's last violation, an intermediate landfill cover issue, in November 2023; it was corrected, and the last enforcement letter to the landfill was issued back in August 2022.
Public Pressure to Move Faster
The slow pace has frustrated some local officials and residents who track the site. Geoff Ellsworth asked for a firm Clover Flat closure timeline at the Upper Valley Waste Management Agency board meeting, arguing that closing the landfill sooner would reduce fire and contamination risks. Chris Malan, a longtime critic of the landfill, expressed disappointment that closure plans were being drawn out.
The delay also comes as the landfill's oversight agency faces separate federal scrutiny. In December 2023, the FBI and the U.S. Department of Justice served a subpoena on the Upper Valley Waste Management Agency requesting records, bids, quotes, and communications regarding waste service contracts and landfill operations dating back to January 2019, according to Waste Dive. In December 2024, the San Francisco Bay Regional Water Quality Control Board and the Napa County Local Enforcement Agency published a joint investigation report addressing water quality complaints against Clover Flat and Upper Valley Disposal, underscoring that multiple agencies continue watching the site even as the shutdown paperwork stalls.
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