WINDOM, MINN. – Residents concerned about noise pollution are pushing back against a proposed crypto mining facility just outside this Cottonwood County city.

Colorado-based Revolve Labs has asked the county for a conditional use permit to run a facility it says will employ three to five people and generate $35,000 a month in service fees for Windom, which is about 65 miles south of Mankato.

But many residents said they were skeptical of the company's claims at a public hearing on the crypto mining facility that drew about 100 on Thursday.

"Your business is not welcome here," Windom resident Dustin Harrold said at the hearing. "When a company like yours comes into my county, and challenges my small town ideas, I get a little riled up."

Revolve Labs, formerly known as Bit49, operates a crypto mining operation in Glencoe, Minn., that has faced complaints by residents of excessive noise from the facility.

Crypto mining uses huge amounts of computing power to solve complex mathematical puzzles and produce cryptocurrency such as Bitcoin, a digital currency that can be traded outside the normal banking system. The machines used for these operations operate around the clock and need to be cooled by banks of fans.

Over the past few years, the noise of these fans has led to complaints from residents living near crypto mining facilities in Texas, North Dakota and Arkansas.

When it opened in 2022, the crypto mining facility in Glencoe had sound levels of 80 to 85 decibels, about the same as a gasoline-powered lawnmower or leaf blower. The company later said it had taken measures to dampen the noise there.

Jeff St. Onge, senior operations manager at Revolve Labs, said Thursday the company has gone to great lengths to prevent noise pollution at the proposed Windom location. The company plans to install 12-foot-tall berms along the property and an alarm system where residents can monitor decibels levels coming from the fans. He said the closest residents will experience sound levels of 41 decibels, similar to current levels there.

St. Onge said the facility would not affect energy prices for Windom residents and that the company chose the area due to its cool weather, good energy rates and proximity to wind farms.

Most of the 100 residents at Thursday's public hearing appeared skeptical about the company's claims. The most common concern was noise.

"I like the quiet out there," said Jay B Kipfer, who lives across the street from the site of the proposed facility. "I go out there at night, I hear the coyotes, I hear all the crickets. You guys come in there, I won't hear that anymore. It'll be a totally different life out there, for me and everybody else, and that sound is gonna resonate across Cottonwood Lake."

Others spoke of the effect on home values, with some speakers questioning whether crypto mining benefits society.

The volume of the murmuring crowd at times reached a decibel level of about 70, according to Tiffany Lamb, Windom's development director. At one point, Cottonwood County Commissioner Norm Holmen said he couldn't hear a question because of a box fan blowing behind him.

St. Onge acknowledged the company's past problems at the Glencoe location but said the two situations were different. The Glencoe facility is in an industrial area with buildings that can reflect sound, while the Windom location would be outside the city.

"We're not here to talk about Glencoe, we're here to talk about Windom," St. Onge said.

The public hearing ended with a recommendation for a moratorium on conditional use permits for crypto mining in the county, pending a study on the environmental impact of the facility. St. Onge said that could delay work at the facility until next year.

Hilary Mathis of Windom said she fears the project will continue after the environmental assessment.

"It's such a new industry and there are no ordinances to prevent them," Mathis said.