A crypto-mining company in Pennsylvania is seeking to burn tires to produce bitcoin, prompting an outcry from residents and environmental groups.
Stronghold Digital Mining says it is repurposing waste materials, while opponents worry about the risks of emissions to human health.
The production of cryptocurrency is an enormously energy-intensive process. Its electricity consumption accounts for an estimated 113 terawatt-hours a year, which is roughly the amount of electricity that countries such as Kazakhstan, the Philippines and Ukraine each used in 2022.
Stronghold has been burning coal waste to create cheap power for cryptocurrency since 2021, when it bought the Panther Creek power plant in Nesquehoning, Pennsylvania. It is a controversial approach because although the removal of coal waste can help remediate contaminated land, the process emits greenhouse gases and other harmful chemicals. It can take twice as much waste coal to produce the same amount of electricity that regular coal would produce.
The company also says it sometimes needs to burn tire-derived fuel – made of shredded vehicle tires – to make the combustion of waste-coal more efficient.
Additives such as the tire fuel “are especially needed when the quality of the coal refuse is low in energy content”, Stronghold spokesperson Naomi Harrington told the Guardian. The crypto miner, which receives state subsidies to burn waste coal, already holds a temporary permit to test the use of tire-derived fuel. It is seeking permanent permission for tires to comprise up to 15%, or 78,000 tons, of its fuel.
“I was shocked,” said Carol Etheridge, who lives less than five miles away from the Panther Creek plant. “It’s terrible. I can’t even believe that people would be allowed to burn tires.”
The US Environmental Protection Agency has in the past – on an archived webpage last updated in 2016 – described burning tires for fuel as preferable to landfilling them, although environmental advocates criticize the practice.
“It poses risks to the health of people living nearby,” said Charles McPhedran, an attorney with Earthjustice, which is fighting the company’s tire application. “This sort of disposal of tires is a last resort.”
Combusting tires can create dioxins and furans, highly toxic chemicals linked to cancer and known to be slow to break down in the environment. Polycyclic aromatic hydrocarbons (PAHs), several of which are carcinogenic, are also associated with burning tires.
“They are clearly looking to reduce their fuel costs,” said Rob Altenburg of local environmental group PennFuture. “There is no analysis for how this will add to the existing burden of legacy pollution in the area.”
The facility is within two miles of communities the state has defined as environmental justice areas. Residents of Carbon county, along with environmental groups, have sent letters of concern to the county commissioner and the Pennsylvania department of environmental protection (DEP).
Stronghold Digital Mining has received seven violations from the DEP for not complying with emissions standards.
It said in a statement to the Guardian that its operations use the “best available control technology for air pollution controls”.
It also said that by burning waste coal, “Stronghold has reclaimed over 1,050 acres of once-unusable land in Pennsylvania. Without these operations, the waste coal would remain unremediated and continue to harm local communities by polluting waterways and emitting toxins into the atmosphere without any sort of emissions control.”
There is an active local debate on whether it is environmentally sound to burn coal waste owing to the pollution this releases. If it remains in place it can leech toxins.
Now the question of tires has come to the fore.
“Burning tires, to fuel something like bitcoin or cryptocurrency, which gives no value to anybody here locally, in my mind, is really unacceptable,” Etheridge said.
