A coalition of health and environmental organizations filed a lawsuit on Monday challenging the U.S. Environmental Protection Agency's decision to repeal federal limits on mercury and other hazardous air pollutants from coal-fired power plants.
The group, which includes Earthjustice, the American Lung Association, the Natural Resources Defense Council and the American Academy of Pediatrics, brought the case in the U.S. Court of Appeals for the D.C. Circuit. The suit targets the EPA action in February that reversed a 2024 update to the Mercury and Air Toxics Standard (MATS).
According to the coalition, the Biden administration's 2024 MATS update would have tightened allowable mercury emissions from coal plants by 70% and cut emissions of nickel, arsenic, lead and other toxic metals by two-thirds. The Environmental Defense Fund estimated that the 2024 update would have produced roughly $420 million in reduced health costs through 2037.
In addition to repealing the 2024 update in February, the EPA under the current administration last year issued a two-year exemption from air quality standards for older coal-fired plants. Those exemptions relieved some of the largest emitting facilities from immediate compliance with limits, the coalition says.
The groups report that since the exemptions were granted, nationally measured sulfur dioxide emissions have risen by 18% and neurotoxic mercury emissions have increased by 9%. In a statement included with the filing, the coalition criticized the administration for not only rolling back rules but also for reducing monitoring capabilities that reveal emissions from individual smokestacks.
"This administration is not just rolling back rules, it is eliminating the monitoring infrastructure needed to know what is coming out of these smokestacks in the first place. It is allowing coal plants to spew out more neurotoxic mercury into our air and food supply, while simultaneously keeping the communities most at risk in the dark about how serious that threat is," the coalition said.
The litigation seeks to reverse the regulatory changes that the coalition says weaken protections for children and other vulnerable populations. The groups argue the combined effect of repealing the 2024 MATS update and issuing temporary exemptions undermines both emissions controls and transparency.
The suit is the latest legal challenge arising from changes to federal air pollution rules affecting coal-fired power generation. The plaintiffs have focused on the implications for public health and on the monitoring information that communities rely on to understand local pollution risks.
Because the lawsuit is newly filed in the D.C. Circuit, its ultimate legal and regulatory outcomes remain pending before the court.