GarCo landfill uses microbes to treat soil fouled by oil
RULISON — Garfield County is relying on tiny organisms to help deal with a big problem associated with local oil and gas development.
A pilot facility at the county’s landfill at the base of the Roan Plateau near Rulison is using microbes to clean petroleum-contaminated soil. The facility is the first of its kind in Colorado, officials say, and unique for a public facility in terms of the blend of technologies it incorporates.
It can accept waste mainly coming from the oil and gas industry and clean it to a point that the landfill will be able to use the treated soil as a cover material over waste. That will prove to be a valuable byproduct of the process because soil is hard to come by at the facility.
County officials envision the facility meeting a regional need faced by energy companies, eliminating in some cases the need for companies to ship contaminated soil to out-of-state facilities, such as in Utah.
“This is a groundbreaker, and I don’t mean that as a pun,” Garfield Commissioner Mike Samson said at a ribbon-cutting ceremony for the facility Wednesday.
He said the approach has national, and even global, implications, and he hopes others will replicate it.
The treatment concept arose during strategic solid waste management planning undertaken by the county in 2014. Petroleum-contaminated soil, or PCS, consists of materials such as cuttings produced during well drilling, soil cleaned up in spills, and so-called “filter cakes” produced in gas-processing operations. Gary Webber, vice president with Northwest Colorado Consultants, Inc., an environmental and engineering firm that works with the county on landfill matters, said the treatment concept grew out of the fact that the state Air Pollution Control Division, citing provisions of the federal Clean Air Act, stopped the use of untreated PCS as landfill cover.
Webber said the approach devised by the county was so novel that state air regulators had to develop a cleanup standard that would apply for the facility.
The county received a $300,000 energy-impact grant from the state Department of Local Affairs for the project.
Robert Legrand is a senior engineer with AECOM, which designed the system and is helping operate it. He said it is unique in that it combines two different treatment technologies that he’s never seen used in combination by a public entity, and that he’s only seen one private U.S. entity combine, in the Great Lakes region.
“The science made sense. It made sense to combine the two,” he said.
While there have been surprises along the way, the pilot project has proven very successful, he said.
One of the technologies is what’s called a biopile, which involves mixing the contaminated soil with a bulking agent like wood chips, nutrients such as nitrogen and phosphorous, and sometimes a microbial “inoculum” such as manure. The mixture is kept moist and is piled on perforated pipes to allow aeration, and the microbes biodegrade the hydrocarbons in the soil.
But biopiles are meant to be used in a onetime process in which the pile is removed once it’s done and the project is considered done. Garfield County is looking to treat soil over years or decades to come, so it also incorporated aspects of what is called static pile composting, an ongoing process used at waste treatment facilities. Static pile composting uses sewage sludge and other waste mixed with a bulking agent that aids in air flow, laid on top of perforated pipes or aeration channels through which air can be pumped.
Garfield’s system is a static-type approach in some respects, such as the incorporation of a system to pull air through the pile, and the fact that it’s set up as a permanent treatment facility. But the system uses contaminated soil and wood chips instead of sludge and yard waste.
“This thing, based on our information so far, it’s done a knockout job. It’s done really well,” Webber said.
He called the system an environmentally responsible means for protecting public health and the environment. The system also allows the landfill to accept materials that it was barred from accepting previously due to their high contamination level, such as filter cakes.
The system went into operation in mid-July, and the pilot pile heated up quickly, to some 160 degrees, indicating that the naturally occurring microbes were doing their job. “They’re in the soil. You just need to give them what they need and they grow like crazy,” Legrand said.
By Labor Day, the soil in the pilot project was clean, he said. Now, officials are seeing how the system will work in cold winter. Legrand is optimistic it should be able to operate most or all of the year because heat should be able to be retained deep in the pile.
The operation also incorporates a biofilter that uses microbes to clean remaining air pollutants. Comparatively, another PCS treatment approach called land farming allows pollutants to escape into the atmosphere. Legrand said the facility is designed to be expandable, and has a state permit to treat 14,000 tons per year.
Fees charged to companies using the facility will fund its operation. Garfield Commissioner Tom Jankovsky said the facility is an important piece of infrastructure to help support the industry, which is important to the economy of western Garfield County. While it’s in a downturn now, he pointed to the Piceance Basin’s continuing potential for future drilling due to the huge size of its natural gas reserves. “I think there’s going to be a long life for this particular facility,” he said.
Don Simpson is a vice president for Ursa Resources, which drills locally. Asked about the new treatment site, he said by email, “we encourage any facility or technology improvement that makes the industry footprint less on the communities where Ursa operates.”