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'We're running off microbe farts': A tour of Calistoga's Clover Flat Landfill

A crane sorts trash at Clover Flat Landfill.

Have you ever wondered why garbage smells bad? The answer is one that would bring a smile to the face of the average third-grader.

“We’re running off microbe farts,” said Shane Kohler as he explained how Clover Flat Landfill’s co-generation plant converts smelly, planet-warming methane into electricity for Calistoga.

During a recent tour of Clover Flat, as anaerobic mites gobbled up nutrients and experienced unpleasant bodily functions, landfill staff demonstrated how 31 wells pump gas from the landfill to a flare or to a power plant that produces enough energy to power 800 homes.

Chief Operating Officer Christy Pestoni described the methane-to-electricity program as a “legacy” left by her father, Bob Pestoni, who took the initiative and the financial risk to launch the program long before it became standard practice at large landfills.

Staff also described the efforts they’ve made to prevent fires and stream contamination, and the skill necessary to operate the machines that haul and compact garbage.

The tour took place shortly before neighbors of Upper Valley Disposal Service’s Whitehall Lane facility sued UVDS and Clover Flat alleging ongoing problems with noise, odors and fire hazards. The plaintiffs are calling for the Upvalley’s garbage, recycling and landfill services to be subject to competitive bidding.

Representatives of UVDS and Clover Flat, closely affiliated companies that operate under long-term franchise agreements with the Upper Valley Waste Management Agency, have denied the plaintiffs’ claims.

Kano Galindo oversees an upgraded leachate system that pumps contaminated liquid into storage tanks. From there it's trucked to a wastewater plant in Santa Rosa that’s capable of treating it.

“Equipment was the first thing we improved,” said Galindo. “We’ve updated our gas system. We’ve updated our leachate system.”

From a vista looking down on the landfill, Galindo pointed to where a “firenado” burned a grinder during the Glass Fire. The staff is hoping to repair it, but in the meantime they bought a new one for $1 million.

Operating those heavy machines are workers like Eliot Perez and Joel Berry, who have some of the most crucial jobs at the landfill.

They have to evaluate each load of garbage and make some mental calculations: Will it compact easily? Will it slide? Where should it be deposited on the slope?

“If you don’t build it right, it’s not going to compact right,” said Berry, the compactor's lead operator. “And if you put too much trash on, it’s not going to compact right either.”

“If you have an operator who doesn’t think through those things, you end up with a big mess,” said general manager Bryce Howard, adding that Berry has done a stellar job. “You end up using a lot more soil and you don’t get a nice smooth surface.”

The landfill experienced some major problems in 2019. Contaminated water ran into a nearby seasonal creek and a string of fires started at the landfill, drawing heavy scrutiny from regulators, including the local enforcement agency that inspects the landfill.

There was also an incident where containment tanks used to store leachate were found to contain low levels of radioactivity due to their prior use in fracking operations in North Dakota.

Since then, the landfill has improved its maintenance and erosion control measures, implemented a fire mitigation program in consultation with Cal Fire, and used new methods to cover the landfill.

Meanwhile, Pestoni family went to court in 2019 to wrest control of the company away from founder Bob Pestoni. His daughter, Chief Operating Officer Christy Pestoni, brought in a new management team led by people who previously worked for larger companies like Waste Management.

Peter Ex, who inspects the landfill, told the St. Helena City Council in March that the landfill and the Whitehall Lane facility “drastically improved” under the new management team. The San Francisco Bay Regional Water Quality Control Board conducts routine inspections and hasn’t found any problems recently, Ex said.

The next step for Clover Flat is a proposed biomass gasification plant that would use wood to produce about 1 megawatt of power, exceeding the 0.8 megawatts already generated by the methane plant.

Christy Pestoni described the plant as “the second generation” of the technology installed by her father.

“This will add another engine, produce another megawatt, and reduce what we’re putting in the landfill,” she said.

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Related to this story

Upper Valley Disposal Service, Upper Valley Recycling and Clover Flat Landfill issued a detailed statement Friday denying allegations leveled by neighbors in a recent lawsuit, while two of the plaintiffs spoke out about how the companies’ operations have affected their lives.

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