A Carbon County power plant’s plans to burn old tires to fuel bitcoin mining operations is leaving activists and some county residents worried about cancer and climate change-causing pollutants.

Panther Creek, a 33-acre plant in Nesquehoning, has been owned by Stronghold Digital Mining, a bitcoin mining company, since 2021. Panther Creek is only permitted to use coal refuse, also known as anthracite culm, which is coal scrap that was discarded due to its poor quality and is often mixed with rock, shale, slurry, slate, clay and other materials.

The process of mining bitcoin is highly energy-intensive, requiring a large number of specialized computers or mining machines that need to run 24/7. Energy generated at the Panther Creek plant is retained by Stronghold for its crypto-mining operations; none of it goes into the power grid. Stronghold also receives Coal Refuse Energy and Reclamation Tax Credits and Pennsylvania Tier II Alternative Credits from the state.

Now, to help supplement the coal refuse it uses to power its energy-intensive bitcoin mining operations, Panther Creek and Stronghold are seeking permission from the Pennsylvania Department of Environmental Protection to burn tire-derived fuel as a supplement, meaning it would comprise up to 15% by weight of the fuel it burns per month. Like coal refuse, scrap tires are also cheap and some research has shown they produce more energy than coal.

The application, filed by Osman Environmental Solutions on behalf of Stronghold and Panther Creek in July, states the plant has already tested the abilities of its boilers to combust tire-derived fuel under temporary approval from the DEP. During this test period, Panther Creek said it was able to remain within its plantwide pollution emission limits.

The application also states that tire-derived fuel is “widely recognized as a valuable fuel when combusted in a well-controlled boiler.”

But local, state and national environmental activists say if the DEP gives Panther Creek approval to burn tire-derived fuel, it will only deepen the pockets of Stronghold’s executives and investors at the expense of the environment and residents of Carbon County.

“Carbon County is a very lovely county but we tend to allow other places to take advantage of us,” said Linda Christman, president of Save Carbon County and a Towamensing Township resident. “Here we have a company that is racing to the cheapest, dirtiest fuel they can use. They’re already using culm piles, which is dirty coal. Now they want to add an even dirtier fuel to it, which is tire shreds, and why do they want to do that? Because it’ll make them a little more money.”

In an emailed statement, Naomi Harrington, a spokesperson for Stronghold, said Panther Creek employs 65 people, of which only two are part-time. She said the plant’s operations have also allowed for the successful reclamation of 1,050 acres of once unusable land in Pennsylvania.

Harrington added that the Panther Creek plant uses air pollution controls that remove the majority of nitrogen oxide, particulate, mercury and sulfur dioxide from its emissions.

However, activists argue the environmentally friendly light that Stronghold shines on its operations is far from accurate. Panther Creek has been cited for violating air emissions regulations seven times since Stronghold took ownership, DEP records show.

The application states the Panther Creek facility is a major source of sulfur dioxide, carbon monoxide and nitrogen oxide, all of which are harmful to humans. It also states the facility releases significant emissions of inhalable particulate matter of various sizes.

“The kind of waste coal that gets used at Panther Creek in particular is a low efficiency coal so you end up with air particulate. One that’s a particular concern is particulate matter 2.5, a very fine particulate that is known to have negative health effects like respiratory disease, increased rates of asthma and cancer,” said Emma Bast, a staff attorney with PennFuture.

Beyond leaving the coal in the ground and not mining it at all, there is no truly environmentally friendly way to deal with coal refuse, Bast said. Piles of coal refuse that dot areas of coal country not only are unsightly but are major sources of water pollution and can easily catch fire. Disposing of coal refuse by burning it as fuel still creates pollutants. According to the application, Panther Creek is permitted to pump hundreds of tons of certain pollutants into the air each year without exceeding the limits set by the government.

And it still leaves behind coal ash as a byproduct, which Stronghold’s website states is used a fertilizer, which is approved by the government but is controversial due to its demonstrated capacity to release arsenic and lead into groundwater.

Christman said if the DEP approves Stronghold’s request, the waste tires they would bring in would come from elsewhere outside the county.

“It’s like many other things in Carbon County; they bring somebody else’s problem here,” Christman said. “They’re bringing a problem from another community to a low-income community. I believe that they think they can get away with it because there’s fewer resources to fight it.”

Tire-derived fuel is managed under a regulatory program and the practice is not new to eastern Pennsylvania or even the Lehigh Valley. The Panther Creek application points to several examples of nearby tire-derived fuel burners, including Northampton Generating Co. in Northampton Township, Hercules Cement Plant in Stockertown, Lafarge North America in Whitehall Township, Essroc Cement in Nazareth Township and Lehigh Cement Co. in Berks County.

Hercules Cement, Lafarge and Lehigh Cement were named as some of the region’s top polluters by a report released in spring.

“The current process with DEP is to add to an existing permit from DEP to burn the tire-derived fuel in a limited quantity, given that several years of testing have proven no adverse effects amongst multiple industries in Northeastern PA and the United States,” Harrington said.

However, activists say burning tires is known to release polycyclic aromatic hydrocarbons, dioxins, furans, metals like zinc and mercury, and other pollutants associated with respiratory diseases, cancer and other serious health issues.

Like coal refuse, waste tires are a major environmental concern when left to sit around. Unlike coal refuse, there are other means of recycling or disposing of waste tires, but even so, tire-derived fuel is still the primary way of reusing tires.

While it is common knowledge that tires will burn and the smoke from a tire fire is toxic, there is a lack of academic research specifically about the local health and environmental effects of burning tire-derived fuel. There are studies that back the practice of burning tires as fuel. One 1997 report by the U.S. Environmental Protection Agency showed that tire-derived fuel produces more energy than coal and can result in fewer emissions than coal, which was cited in Panther Creek’s application.

However, not even the EPA cites that information anymore and environmental activists have also called this report into question with a primary critique being that the conditions used to test tire-derived fuel for the report were ideal ones that do not reflect what really happens at facilities that burn it. And the results of some other studies have contradicted the idea that coal supplemented by waste tires reduces nitrogen oxide emissions or many other types of pollutants, such as one 2005 study that compared bituminous emissions of coal plus tire-derived fuel to just coal.

But at this point, the decision is in the hands of the Pennsylvania Department of Environmental Protection. The formal public comment period is closed but Charles McPhedran, staff attorney for Earthjustice, said.

He said it’s likely that the department may submit some type of bulletin or comment this month providing more details about what comes next.

“We hope they reject it. It’s possible they will ask questions of the applicant about things in the application that are incomplete or unclear or it’s possible they’ll just issue a plan approval,” McPhedran said. “My impression is they tend to issue permits but they do often dig into the details of big permits like this and I can’t really predict their next steps.”

Christman said regardless of what happens, she takes heart in knowing she and others stood up for the county they love.

“Even if we lose, at least we will be showing other polluters that we’re not easy pickings,” Christman said.