Appeals Court Declines to Lift Biden-Era Soot Limits for Coal-Fired Power Plants

A barge on the Ohio River moves past the Mountaineer Power Plant, a coal-fired power plant near New Haven, W.Va., on March 13, 2026. Carolyn Kaster/AP PhotoA federal appeals court on Friday dismissed the Environmental Protection Agency’s (EPA) effort to lift Biden-era limits on fine particulate matter, or soot, from coal-fired power plants and factories, representing a setback to the Trump administration’s actions to loosen environmental regulations on the coal industry.The U.S. Court of Appeals for the District of Columbia Circuit rejected the EPA’s petition and motion for vacatur, leaving the annual limit of 9 micrograms per cubic meter of PM 2.5 in place.“After initially defending the new rule, the EPA now moves to vacate the rule on the grounds that it exceeded its statutory authority and acted unreasonably by failing to consider costs. Because these arguments lack merit, we deny the petitions for review and the motion for vacatur,” the ruling said.The decision comes as the Trump administration works to undo Biden-era environmental rules aimed at coal-fired power generation, which the administration has attempted to revive as part of efforts to bolster reliable baseload energy and reduce electricity costs.The Biden administration’s 2024 rule lowering soot limits was promoted as preventing more than 800,000 cases of asthma symptoms, 2,000 hospital visits, and 4,500 premature deaths annually, according to EPA estimates at the time.Environmental groups welcomed the court’s decision. The Natural Resources Defense Council praised it, saying, “While the Trump EPA dragged its heels, millions of Americans kept breathing unhealthy levels of soot—pollution the science shows has no safe level. This decision removes any remaining doubt: the science has long been clear, and now the law is too.”The Trump EPA had argued that the 2024 rule imposed costs of “hundreds of millions, if not billions of dollars to American citizens if allowed to be implemented” and was not based on a full review of available science. The agency said Friday it was reviewing the decision.This ruling fits into a series of actions and challenges involving coal plant regulations. Earlier this year, the EPA repealed Biden-era amendments to the Mercury and Air Toxics Standards (MATS) for coal-fired power plants, estimating savings of $670 million.EPA Administrator Lee Zeldin said at the time that the rollback would enhance baseload power “while maintaining protections for public health and the environment.” In May 2025, the EPA indicated it was working to remove Biden-era carbon emission limits on coal- and gas-fired power plants, known as aspects of “Clean Power Plan 2.0.” Those rules had required steep reductions in emissions, potentially through carbon capture technology not yet widely deployed at scale.An EPA spokesperson said the agency was reconsidering the rules because they raised concerns regarding overreach and impacts on affordable, reliable electricity.“President Donald Trump promised to kill the Clean Power Plan in his first term, and we continue to build on that progress now,” the spokesperson quoted Zeldin as saying. The administration has also worked to keep aging coal plants operational through emergency decrees to maintain grid reliability. Energy Secretary Chris Wright issued multiple 90-day orders under the Federal Power Act to stop plant closures in states including Michigan, Indiana, Washington, and Colorado, citing risks of blackouts during extreme weather.Critics, including some Democratic-led states and environmental groups, have objected to these orders in court, arguing they exceed federal authority and impose unnecessary costs on utilities and ratepayers. Some utilities reported significant operating losses due to keeping some plants operating at low capacity.