The Trump administration Friday further eroded Colorado’s longstanding mandate to close coal-fired power plants by 2031, saying the state’s required regional haze-fighting plan goes too far and violates the Clean Air Act.
But the regional haze plan covers everything from emissions at the Suncor refinery and Colorado’s three major cement kilns to natural gas power and other pollution sources. In rejecting the entire plan, the EPA may throw many of Colorado’s pollution fighting plans into regulatory purgatory for years.
Colorado’s coal plants are needed for “grid reliability,” the federal government said Friday, though Colorado regulators and environmental groups counter that the state has a carefully constructed, long-term plan for reliably replacing coal with clean solar, wind and battery storage.
The Environmental Protection Agency said it is disapproving Colorado’s required regional haze state implementation plan, intended to clear the air in Rocky Mountain National Park and other public spaces, because the state “put desire to close power plants over federal law.”
“The state’s attempt to shut down many coal-fired power plants” was not needed to meet regional haze requirements, the EPA said, in announcing the plan rejection. The announcement specifically mentions Colorado Springs Utilities when explaining that Colorado’s plan unlawfully closes coal sources “without consent from all the plants.”
Colorado Springs Utilities, controlled by the city, has said it is in discussions with state regulators about keeping its Nixon Unit 1 plant open past the long-planned closure date of 2029.
The EPA on Friday said the state’s haze plan “did not properly consider and explain whether the nonconsensual closure of Colorado Springs Utilities’ Nixon Unit 1 power plant would be an act of taking private property without compensation.”
Cyrus Western, the EPA’s Region 8 administrator for Colorado and surrounding states, said in an interview Friday that Colorado Springs Utilities “has made it clear” they don’t want to close Nixon as scheduled.
The regional haze rules require that states show their policies are “on a glide path” to complying with haze limits over time, Western noted. “It’s also worth noting that the state of Colorado did not need to shut these plants down to remain under the glide path, right? So they could keep these all open, still have clean air, but yet they opted to include them.”
Closing the remaining coal plants over the next few years is, however, also a key part of other state mandates, including reaching the target of an 80% reduction in greenhouse gas emissions from the power sector by 2030. With each coal fired plant emitting millions of tons of carbon dioxide a year out of Colorado’s overall 115 million tons of emissions, the coal plants are the largest single sources to eliminate.
Colorado has six remaining coal-fired electricity generation plants, with the last one scheduled to close under state clean energy mandates and company power plans by 2031.
Colorado officials said despite the EPA’s decision, other state-based laws and rules requiring coal plant closures will remain enforceable.
“The EPA’s decision will negatively impact environmental protections for Colorado and for the majestic national parks and wilderness areas the program was designed to safeguard,” said Air Pollution Control Division director Michael Ogletree, in a statement.
“Colorado submitted a highly protective, innovative plan that met all state and federal requirements to reduce regional haze,” Ogletree said. “Regardless of EPA’s decision, Colorado will continue to lead. Coal plant retirement dates remain in state regulation, and many facilities have already closed or are on track to retire voluntarily because cleaner energy is more affordable and makes economic sense for consumers.”
Gov. Jared Polis said in a statement, “This federal decision is out of touch with the realities of the electric grid in Colorado. Keeping old coal plants online will increase costs to ratepayers, worsen air quality, and make it harder to bring lower cost and cleaner generation on line.”
In December, President Donald Trump’s Department of Energy issued an emergency order demanding that Tri-State Generation’s Craig Unit 1 coal plant stay open past the long-planned Dec. 31 shuttering date. Tri-State is now fixing broken parts at the plant, which it had previously not planned to do given the closure, and will bring it back online. The co-op generator says it has not heard any plan on who will pay the up to $80 million annual cost of running the plant in 2026.
The EPA on Friday cited the Department of Energy’s emergency action in calling out Colorado. “These plants are vital to delivering reliable and affordable energy to Colorado families and meeting the surging national energy demand,” the EPA announcement said.
Environmental groups on Friday echoed Attorney General Phil Weiser’s language this week that the Trump administration actions are politically based and likely to be proven unconstitutional.
“This is yet another unwarranted attempt by the Trump administration to prevent the long-planned retirements of Colorado’s expensive, dirty and unreliable coal plants,” said Michael Hiatt, deputy managing attorney at Earthjustice’s Rocky Mountain Office. Hiatt spoke for a coalition, which includes the Sierra Club and the National Parks Conservation Association, on clean air issues.
“The Trump administration’s ideological attacks on Colorado’s energy policies are illegal and will increase costs for customers, as clean energy in Colorado is far cheaper than coal,” Hiatt said. The groups are still waiting to see the EPA’s full ruling on Colorado’s proposed 2022 haze implementation plan that state and federal authorities have been reviewing for years.
“This administration is fixated on propping up the coal industry by forcing old, expensive, and highly polluting coal plants to stay online,” said Erin Overturf, director of clean energy at Western Resource Advocates. “This decision — like the recent federal order forcing the coal plant in Craig to run beyond its retirement date — disregards the law, infringes on state sovereignty, and imposes unnecessary costs on Colorado energy consumers.”
Weiser said in a press conference Thursday that his office was following the Trump actions on coal plants and would join other states in legal actions to fight them if and when administrative objections have played out.
Asked if the EPA’s rejection was political retribution on Colorado, Western said, “Just look at the time and look at the facts. We are acting well within the bounds of the law. We are ensuring that there is compliance with the law,” Western said, and Jan. 9 was EPA’s deadline to act on the latest version of the plan.
Regional haze plans are part of a network of intersecting portions of the Clean Air Act and state air pollution regulations, often seeking cuts or limits to pollutants that cause many problems other than regional haze. Shuttering coal power plants also reduces greenhouse gas emissions that contribute to global warming, and cuts local health-harming pollutants such as nitrogen oxides, sulfur dioxide, particulate matter. Colorado must also implement a series of new pollution cuts to comply with other parts of the Clean Air Act, including attainment of limits on lung-harming ozone in the northern Front Range.
Utilities have scheduled their coal plant closures for economic reasons, as renewable sources get cheaper, and to meet other Colorado laws including greenhouse gas reduction.
“Colorado is now required to submit a revised, approvable state implementation plan, or EPA will need to complete a federal implementation plan, either of which must be done within two years,” the EPA said. Either plan “will need to fully address statutory requirements, including revisions to Colorado’s long-term strategy.”
“And we absolutely stand at the ready to engage with the state of Colorado, to work with them to come to a reasonable conclusion that is workable for everybody,” Western said in the interview Friday.
The EPA’s background briefing on the history of regional haze plans made it clear the agency under the Trump administration wants more economic considerations taken into account before approving new haze policies.
“Historically, the implementation of this program has imposed significant costs on power plants and other sectors, calling into question the supply of affordable and reliable energy for American families,” the background briefing said. “After years of implementation and feedback from stakeholders, it is clear that the Regional Haze program is broken and needs significant revisions.”
“Actions like these are being sold to the public as protecting them, but in reality actions like these are undermining the very mission of agencies like the EPA,” said Ean Tafoya, vice president of state programs for GreenLatinos.
“As a physician, I’m deeply concerned by the EPA’s decision to block Colorado’s clean air plan,” said Dr. Sara Carpenter, a retired pediatrician and chair of Healthy Air and Water Colorado. “Coal-fired power plants are a major source of the fine particle pollution that sends children to the ER, worsens asthma, and increases the risk of heart attacks and premature death. Framing this as a legal or ‘grid reliability’ issue ignores the very real harm to Coloradans’ lungs, hearts and brains.”
This story was updated at 5 p.m. on Jan. 9, 2026, with additional quotes and information.