For now, one man — Chief Justice John G. Roberts of the United States Supreme Court — may hold the fate of the Colstrip coal plant in his hands.

Lawyers for Talen Montana and NorthWestern Energy, the owners of the aging power plant, have asked the Chief Justice of the U.S. Supreme Court to temporarily stay two rules that the plant’s owners say leave them with two dire choices: invest $350 million in immediate improvements to pollution controls or close the plant, leaving Montana energy customers with high energy rates or unreliable power.

Lawyers for Colstrip’s owners argue in their 38-page emergency appeal to the U.S. Supreme Court that Biden-era pollution rules unfairly target the Colstrip plant, which is frequently labeled one of the dirtiest power plants still in operation in America.

Furthermore, they claim that the U.S. Environmental Protection Agency has adopted stricter pollution regulations without proper justification, making the new rules on particulate matter released from coal combustion and a rule on greenhouse gas emissions arbitrary.

Colstrip’s owners warn that without an immediate halt to the EPA’s regulations, Colstrip won’t have enough time to comply. And even if Colstrip agrees to pay for the estimated $350 million in upgrades, the company won’t have enough time to recoup the costs before the plant is eventually shut down.

At stake, the lawsuit says, is the future of Montana’s energy supply. And it comes at a time when NorthWestern Energy, the state’s largest utility, is embracing fossil fuels, while other companies are increasingly turning to renewables. Some are even building facilities in Montana to power homes and businesses in multiple states.

“The Colstrip Power Plant in Montana is uniquely affected,” the lawsuit says. “Nearly half of the costs of the final rulemaking are imposed on Colstrip even though the EPA failed to demonstrate that additional emissions reductions are necessary to achieve measurable health benefits… additional reductions amount to statistical noise.”

The EPA acknowledges that a large portion of the regulatory burden would fall on Colstrip, nearly half (42%). However, other environmental groups have previously said that the various owners of the Colstrip plant have deliberately failed to upgrade the plant and invest in it to increase profitability.

Colstrip’s owners say that if the new rules go into effect, the plant will be forced to close in 2031. They also say the plant cannot implement carbon capture and storage or co-generate electricity with on-site natural gas turbines, which they say will limit the plant’s lifespan. That would pose “devastating risks to Montana’s economy and electricity reliability.”

“Approximately 3,000 jobs, $200 million in after-tax disposable income and more than a billion dollars in economic output for Montana depend on Colstrip,” the lawsuit states. “As long as investments continue to be made for maintenance, Colstrip could operate for at least another 20 years.”

The emergency declaration states that the new pollution rules combined with greenhouse gas regulations make it impossible to operate the plant long-term because upgrades are needed to close the plant, since there is no plan to co-fire the plant with natural gas or to capture or store carbon emissions. In other words, the Biden administration is requiring the owners to make $350 million upgrades to the plant, but that would only extend its operational life by four and a half years.

“Since the plant has a maximum of four and a half years to recoup those costs by selling power, the capital cost of the controls is economically irrational for the facility,” the lawsuit said.

The legal maneuver and appeal to the highest court in the land, the U.S. Supreme Court, is a long shot. Earlier this summer, Talen’s owners asked the D.C. Circuit Court of Appeals to stay the rule, but the appeals court denied the request on August 6.

Meanwhile, Montana Attorney General Austin Knudsen and a handful of other states have sued the Biden administration, alleging that the government is unfairly targeting coal-fired power plants and endangering the reliability of electricity across the country.

They said the lower courts failed to consider that the EPA’s rules, even though they affect less than 2% of the nation’s electricity generating capacity, affect an entire state because Montana’s electricity production relies heavily on Colstrip.

“At any given time, Colstrip provides up to 1,480 megawatts of net generating capacity,” the report said. “Montana’s demand (and regional demand) is supplied by renewable sources that are vulnerable to seasonal and weather variability.”

Although Colstrip has a capacity of 1,480 MW, the aging plant is also susceptible to criticism. For example, the plant is said to generate much less electricity than its capacity allows during the hottest and coldest periods of the year.

“Without delay, Colstrip’s fate will be sealed by the time this litigation runs its normal course,” the document reads. “Even if NorthWestern were to successfully collect on those rates after an unpredictable rate-recovery hearing, those costs would fall on Montana’s electric customers. Opponents may downplay $350 million as minuscule for a national rule, but those costs have real consequences when concentrated in a sparsely populated state.”

NorthWestern also claims it cannot replace Colstrip’s capacity and that there are no other sources, even as the company builds a controversial natural gas-fired power plant in Laurel.

“There are no feasible means in the short term to replace Colstrip’s capacity with other existing NorthWestern capacity or through market purchases from other sources,” the complaint states.