The U.S. Environmental Protection Agency’s decision to fully disapprove Colorado’s revised Regional Haze State Implementation Plan is landing at the intersection of energy reliability, environmental protection, and federal-state authority — a familiar crossroads in modern environmental policy.

The EPA concluded that Colorado’s 2022 plan did not comply with the Clean Air Act because it proposed mandatory shutdown timelines for certain coal-fired power plants without the consent of all facility owners. According to the agency, forcing closures through a regional haze plan exceeds what the law allows and could jeopardize both property rights and grid reliability.

At the center of the dispute is the Regional Haze Rule, a long-standing Clean Air Act program designed to improve visibility in national parks and wilderness areas. States are required to submit plans outlining how they will reduce emissions that contribute to haze, particularly from large industrial sources. Colorado’s plan attempted to meet those visibility goals by setting closure deadlines for several coal plants, including Colorado Springs Utilities’ Nixon Unit 1.

EPA rejected that approach, saying Colorado failed to demonstrate that nonconsensual closures would be legally permissible or consistent with federal law. The agency also raised concerns that the plan did not adequately consider whether forcing a plant shutdown could constitute a taking of private property without compensation.

Beyond legal issues, EPA framed its decision around reliability. The agency pointed to recent developments that underscore Colorado’s changing energy landscape, including the state’s withdrawal of a planned closure deadline for Comanche Unit 1 and a December 2025 emergency order from the Department of Energy requiring Craig Station Unit 1 to continue operating to maintain grid stability.

From EPA’s perspective, those examples reinforce a broader concern: that retiring baseload generation too quickly can strain power systems, especially as electricity demand grows due to manufacturing expansion, electrification, and data-intensive technologies like artificial intelligence.

Colorado officials and environmental advocates see the situation differently. They argue that coal plants remain a major source of haze-forming pollution and that Colorado’s plan was a reasonable attempt to meet federal visibility requirements while continuing the state’s transition toward cleaner energy. From this view, EPA’s disapproval delays meaningful progress in improving air quality in some of the country’s most iconic landscapes.

Critics of the EPA’s decision also point out that regional haze planning has long relied on emissions controls and plant retirements as tools for reducing visibility impairment. They worry that limiting states’ ability to include enforceable closure deadlines could weaken the program and shift more authority back to federal regulators through a future federal implementation plan.

That possibility is now on the table. Colorado has two years to submit a revised, approvable plan. If it does not, EPA is required to step in with a federal implementation plan, which would set haze-reduction requirements at the federal level. While EPA has said it wants to work cooperatively with the state, the clock is now running.

The broader debate reflects a tension that has defined environmental policy for decades: how to balance clean air goals with affordable, reliable energy. EPA argues that regional haze compliance does not require shutting down power plants that are still needed to keep the lights on. Environmental groups counter that visibility and public health suffer when coal plants remain in operation longer than necessary.

Adding another layer is EPA’s recent decision to extend the deadline for states’ third-planning-period regional haze plans from 2028 to 2031. The agency says the extension gives states more time to adapt to potential changes in the rule itself, which EPA has suggested may need restructuring.

For now, Colorado finds itself in a familiar regulatory limbo, caught between federal oversight and state policy ambitions. The outcome of the revised plan — or a potential federal replacement — will likely shape not only the state’s energy mix, but also how much flexibility states retain in navigating the evolving balance between environmental protection and energy reliability.