U.S. Faces Legal Challenge Over EPA Rollback of Mercury Pollution Limits

A coalition of major health and environmental organizations has filed a lawsuit against the Environmental Protection Agency, challenging its decision to roll back federal limits on mercury and other toxic emissions from coal-fired power plants.

The case, brought before the U.S. Court of Appeals for the D.C. Circuit, includes groups such as Earthjustice, American Lung Association, Natural Resources Defense Council, and the American Academy of Pediatrics.

At the center of the dispute is the repeal of the 2024 update to the Mercury and Air Toxics Standard, which had aimed to significantly curb mercury pollution and other hazardous air pollutants. The Biden-era rule was projected to cut mercury emissions by 70% and deliver substantial public health benefits.

Plaintiffs argue that the rollback endangers vulnerable populations, particularly children, by increasing exposure to neurotoxic pollutants. They also highlight concerns over reduced emissions monitoring, claiming communities may be left unaware of rising health risks.

The lawsuit follows additional exemptions granted to older coal plants, which the coalition says have already contributed to rising pollution levels nationwide. The case marks a significant escalation in legal resistance to the administration’s broader environmental deregulation agenda.

Mercury and Air Toxics Standards litigation adds another front to the growing legal challenges against Trump-administration environmental deregulation. The 2024 MATS update was projected to deliver 70 percent mercury emissions reduction from coal-fired power plants - a substantial public-health benefit particularly for children and vulnerable populations exposed to neurotoxic mercury and other hazardous air pollutants.

The coalition composition (Earthjustice, ALA, NRDC, American Academy of Pediatrics) signals a health-focused legal strategy rather than purely environmental framing. Public-health arguments have historically fared better in US federal courts than pure environmental-benefit arguments, particularly when tied to specific vulnerable populations. Reduced monitoring provisions in the rollback create additional grounds for challenge.

For power generators, coal-industry participants, financial institutions supporting sector investment and their insurers, Cognitud's climate action, sustainability due diligence and impact assessment teams help clients evaluate exposure to mercury-and-air-toxics litigation risk, structure compliance strategies robust across regulatory scenarios, and prepare disclosures aligned with CDP, ISSB S2 and jurisdictional air-quality frameworks that increasingly determine investor and community engagement outcomes.