Landfill in Virginia, Minn., will turn heat from garbage into energy used to treat wastewater

A 10-acre cell at the St. Louis County landfill in Virginia, Minn., has been outfitted with coils at its base, a geothermal liner that will collect heat from garbage that will then be used at a wastewater treatment plant planned for nearby.

It is the first of its kind in the state, according to a news release from the county — and will likely provide the blueprint for similar sites, including one in Canyon, Minn.

The geothermal liner will collect heat, up to 120 degrees, from the decomposing garbage packed in above it. That energy will be transferred about a quarter-mile to a leachate wastewater treatment plant, where water that has run through the landfill will be stripped of contaminants, including PFAS, using filters and other technology, according to the county.

“In this area, where we have the cleanest water in the state, we want to make sure we protect it,” Keith Nelson, chair of the St. Louis County Board, said in a news release. “I’m so proud of our staff for their forward-thinking work to remove forever chemicals from leachate at our landfill.”

The county is collecting bids for the leachate treatment plant, which is expected to be operational in 2026.

The landfill currently treats up to 6 million gallons of leachate per year, which is contained in two holding ponds and then dispersed over large grass fields. It serves about 92,000 residents from 6,300 square miles, a swath that excludes Duluth and its surrounding communities, according to St. Louis County officials.