Colorado has joined 29 states and cities in suing the Environmental Protection Agency over a new rule that would replace the 2015 Clean Power Plan.

State Attorney General Phil Weiser announced Tuesday that a lawsuit was filed in the Washington, D.C., Court of Appeals over what’s known as the Affordable Clean Energy Rule.

Announced on June 19, the rule would eliminate the Obama administration’s Clean Power Plan, which is intended to reduce carbon dioxide emissions from power plants, primarily coal-burning facilities.

According to the EPA’s announcement, the prior plan was “overreaching,” and the new rule would restore the rule of law, empower states and support energy diversity.

The 2015 Clean Power Plan was never implemented. In 2016, the U.S. Supreme Court granted a stay sought by 27 states to halt its implementation. In August 2017, the Washington, D.C., Court of Appeals gave the new administration 60 days to review the Clean Power Plan and come up with an alternative. 

EPA Administrator Andrew Wheeler announced in May that the new rule and accompanying plan is necessary to “rectify inconsistencies” in the agency’s approach to how it analyzes costs and benefits.

Wheeler explained in his memo that the new rule would follow a Trump administration executive order that requires agencies to “identify regulations that impose costs that exceed benefits.”

During a public comment period in April, Wheeler said numerous stakeholders had “identified instances when the agency underestimated costs, overestimated benefits or evaluated benefits and costs inconsistently. Per the executive order and based on these public comments, the EPA decided to take further action to evaluate opportunities for reform.”

The change was hailed by industry groups such as the American Wood Council, which applauded the EPA’s “plain reading” of the Clean Air Act. In a statement in June, the council said the new plan would allow mills that reduce their emissions below Clean Air Act thresholds to “be free of onerous additional reporting, monitoring and record-keeping requirements as long as they operate to stay below the cutoffs.” The organization called the change an incentive for reducing emissions.

Weiser said Tuesday that the lawsuit alleges the EPA is “failing to uphold its legal duty to regulate air pollutants when they pose a risk to public health.”

“The EPA’s rule rolls back nationwide limits placed on fossil-fuel power plants and will have virtually no impact on these emissions,” he said. “The rule would also obstruct the progress that states like Colorado are making toward clean, renewable and affordable electricity generation. Finally, the rule disregards the U.S. Supreme Court’s directive to the EPA in Massachusetts v. EPA to regulate carbon emission under the Clean Air Act.”

According to a statement from Weiser’s office, the Clean Air Act requires that limits on air pollutants must be based on the emissions reductions achievable through the “best system of emission reduction.”

That system, included in the EPA’s new rule-equipment upgrades at coal power plants, will reduce emissions by 0.7% more by 2030 than having no rule at all, according to EPA’s own analysis.

Further, EPA found that, under its rule, emissions of one or more of three pollutants – carbon dioxide (CO2), nitrogen oxide (NOx) and sulfur dioxide (SO2) – will increase in 18 states by 2030.

In addition to 21 states, municipalities including Chicago and Boulder are also included as plaintiffs in the lawsuit.