Big air quality problems in Big Sky Country

Proof of problems: Bitcoin mining’s pollution toll on U.S. communities

‘They almost look like fortresses, with barbed or razor wire surrounded by open prairie’

Melissa Nootz, Montana Environmental Information Center campaigns and advocacy director

BIG HORN COUNTY, Mont. – Big Sky Country has a big air pollution problem, thanks to cryptocurrency mining. Air pollution and greenhouse gas emissions continue to rise as a result of flaring, coal-fired power plants and other energy sources working 24 hours a day, seven days a week, just to “mine” bitcoin.

Snapshots of some of the bitcoin mining operations blighting the Montana landscape show just how out of place the operations can be: Rolling prairie land, bales of hay, the very image of peace and serenity – then row after row of metallic gray rectangular facilities that house mining machines whirring on a never-ending schedule. Noisy giant fans atop the mining containers stand out like oversized pimples on the horizon. And dramatic orange flames twist skyward from nearby gas flares used to power the mining computers, individually no bigger than two shoeboxes but gathered together by the hundreds or thousands.

And it’s not just the flaring of natural gas that powers these mines, because Montana illustrates perfectly how this smoke-and-mirrors industry has turned to resurrecting once-closed coal-fired power plants in order to generate the electricity needed by bitcoin mining. Proof of work crypto mining is putting these dirty fossil fuel power sources back to work.

Preying on the impoverished

As residents of the second poorest county in Montana, the people in Big Horn County could have been forgiven for thinking there might be a jobs boost after cryptocurrency miner Marathon Digital Holdings agreed to let the owner of a local coal-fired power plant generate the electricity for its bitcoin mining needs.

Instead, the county got spikes in emissions of carbon dioxide, sulfur dioxide, and nitrogen oxides once energy-intensive bitcoin mining operations began. Emissions increases can have devastating impacts on people living nearby, costing the U.S. economy billions through premature deaths and illnesses, and carbon dioxide adds to the climate crisis.

Private property sign posted in front of Hardin Generating Station, in Hardin, Mont.

Private property sign posted in front of Hardin Generating Station in Hardin, Mon.

Photo credit: Associated Press

The Montana plant, known as the Hardin Generating Station, owned by Beowulf Power, was first slated to close by 2018, until the deal with Marathon extended the facility’s life for years.

In Hardin’s prior life as a coal-fired power plant generating electricity for the surrounding area, the Montana Environmental Information Center, or MEIC, an environmental advocacy group, successfully fought to impose modern air pollution controls. But even with those safeguards, the revived Hardin plant still produces emissions that threaten public health and add to the climate catastrophe as it works overtime for crypto mining.

Polluting pristine wilderness

The American Lung Association’s 2022 “State of the Air” report gave Missoula County, Mont., an “F” for the air pollution caused by particulate matter, also known as soot, emissions over 24 hours. MEIC warned it could put at risk the health of people breathing that air. Energy generation for bitcoin mining – whether that’s flaring gas in an open prairie field or bringing a coal-fired power plant back to life – inevitably leads to more air pollution.

Flare gas burning outside of mine in Hardin, Mont.

Flare gas burning outside of Big Horn Data Hub in Harding, Mon.

Photo credit: Montana Environmental Information Center

In 2021, Marathon’s operations at the Hardin plant produced 755,700 tons of carbon dioxide emissions – its highest annual emissions since 2014. That year it also generated 304 tons of sulfur dioxide and 245 tons of nitrogen oxides.

The amount of coal used to generate electricity at the facility had declined over 82 percent from 2014 to 2017, when the Hardin plant’s closure was originally announced. But in 2021, when Marathon began mining bitcoin at an adjacent facility, the coal plant’s output increased by 816 percent. During the first three months of 2022, it was on track to raise its output by another 45 percent over the 2021 level, with emissions increases an inevitable byproduct.

Today, even the crypto mines using renewable sources of power draw criticism. Opponents say the facilities leech power and further stress already strained renewable energy supply chains that should be used for communities and other critical infrastructure. 

Bitcoin miners ‘not upfront’

Neighborhoods are often not told when crypto mines will appear, finding out only when they see flare gas burning or hear the constant noise from the machines and cooling fans. 

“It’s very opaque,” says Anne Hedges, MEIC director of policy and legislative affairs. “These companies are not upfront about what they are doing.”

Marathon last year announced plans to shutter the Hardin plant and transition to 100 percent carbon-neutral bitcoin production with renewable power sources.

“Marathon made a commitment for our mining operations to be 100 percent carbon neutral by the end of 2022,” said Marathon Chairman and CEO Fred Thiel in an April 2022 statement

“To achieve that goal, we have endeavored to ensure our miners are as sustainably powered as possible. . . . [W]e believe it is an appropriate time to transition our legacy operations away from fossil fuel generation and towards more sustainable sources of power,” Thiel said.

Hardin is still operating, Hedges says, despite Marathon’s pledges to move its operations to Texas. “It’s unclear whether there’s another operation in there.”

Noisy giant fans atop the mining containers stand out like oversized pimples on the horizon.

Some crypto mines are incongruous with the otherwise picture-perfect landscapes of Montana, further harming the quality of life for residents exposed to the facilities’ air and noise pollution, while also having to put up with jarring images of unsightly mining operations. 

“Some of these mines are just rows on rows of shipping containers in the most remote parts of Montana,” says Melissa Nootz, MEIC campaigns and advocacy director. “They almost look like fortresses, with barbed or razor wire surrounded by open prairie.” 

Hedges wants to see federal action rein in crypto mining and is calling for strict regulation of the industry by the Securities and Exchange Commission. But in the absence of comprehensive federal policy, communities are left to fight proof of work mines on their own.

That requires people to be vigilant, monitoring the news for stories about bitcoin mines coming to town. Hedges warns some operations might call themselves “data centers” – a term that describes a very different type of facility, and that companies sometimes use to disguise what’s actually a bitcoin mine. She also suggests tracking environmental permits and pushing to restrict the zoning of bitcoin proof of work operations. 

But, she notes, it can be an uphill fight. Missoula County in 2021 established first-in-the-nation zoning regulations restricting where and how crypto mines can be located. “We got really lucky, because that’s the most progressive county in Montana,” Hedges says. “In the rest of the state, zoning is a four-letter word.”