The U.S. Environmental Protection Agency has formally rejected Colorado’s revised regional haze plan, blocking the state from imposing shutdown deadlines on several coal-fired power plants and requiring officials to submit a new proposal within two years.
In a final action announced Friday, the EPA fully disapproved Colorado’s 2022 Regional Haze State Implementation Plan, concluding that the proposal violated the Clean Air Act by attempting to force the closure of power plants without the consent of their owners. Federal officials said the plan failed to provide required legal assurances and raised concerns about electric grid reliability.
The regional haze program is intended to improve visibility in national parks and wilderness areas by limiting pollution from industrial sources. Colorado’s plan sought to meet those goals in part by setting closure deadlines for certain coal-fired power plants. The EPA said those deadlines were neither required under the law nor legally justified.
According to the agency, Colorado did not adequately address whether forcing the closure of Colorado Springs Utilities’ Nixon Unit 1 power plant could constitute an unlawful taking of private property without compensation. Under the Clean Air Act, states must demonstrate that provisions in their implementation plans are enforceable and lawful.
EPA Administrator Lee Zeldin said the decision reflects the agency’s commitment to balancing environmental requirements with energy reliability. “Reliable baseload energy sources are essential to ensuring families have cost-effective energy,” Zeldin said, adding that the agency remains willing to work with Colorado to develop a compliant plan.
Federal officials also cited concerns about power supply stability. The EPA noted that Colorado previously withdrew a proposed shutdown date for Comanche Unit 1 after determining that additional generating capacity was needed. The agency further pointed to a December 30, 2025, emergency order from the U.S. Department of Energy requiring the Craig Station Unit 1 coal plant to continue operating because of grid reliability risks.
EPA Regional Administrator Cyrus Western said the decision supports both clean air goals and dependable energy supplies, particularly as electricity demand grows due to manufacturing expansion, national security needs, and increased use of data centers.
As a result of the disapproval, Colorado must submit a revised regional haze plan that meets federal statutory requirements. If the state fails to do so within two years, the EPA is required to impose a federal implementation plan.
The agency emphasized that it remains in discussions with state officials and is prepared to assist Colorado in crafting a new plan that addresses visibility requirements while complying with federal law.
The ruling does not affect EPA’s broader revisions to the regional haze program timeline. In late December, the agency extended the deadline for states to submit plans for the program’s third planning period to 2031, citing the need for regulatory clarity. That extension does not apply to Colorado’s rejected plan, which covers the second planning period and was originally due in 2021.
To read EPA’s full final action disapproving Colorado’s SIP revision, please click here.
