UPDATE: April 1, 2026: A coalition of 21 states and local governments filed a lawsuit Tuesday challenging the Trump administration’s repeal of the 2024 Mercury and Air Toxics Standards Rule.
In arguing that the repeal is unlawful, the states will attempt to prove that EPA has failed to provide a reasoned basis for the rollback and failed to adequately consider developments in practices, processes and control technologies in its move, according to a press release from Minnesota Attorney General Keith Ellison.
“Mercury is a brain-destroying poison that can cause lasting harm to any Marylander who consumes it, especially pregnant people and young children," Maryland Attorney General Anthony Brown said in a statement. “We are filing this lawsuit to reverse the EPA's reckless rollback and restore the protections that keep our residents and their families safe."
Chicago, New York City and Harris County, Texas, are joining the states in the lawsuit, filed in the U.S. Court of Appeals for the District of Columbia Circuit.
Dive Brief:
- A coalition of public health, environmental and community advocates filed a lawsuit Monday challenging the Environmental Protection Agency’s repeal of limits on mercury, lead and other air pollution from coal-fired power plants and its rollback of real-time emissions monitoring.
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“The repeal violates the Clean Air Act, ignores the scientific record, and abandons safeguards that protect communities living near coal plants and downwind of their pollution,” the coalition stated in a press release.
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The coalition consists of many of the same organizations, including the Environmental Defense Fund and Earthjustice, that sued the EPA in February for rescinding the 2009 “endangerment finding,” a key underpinning for greenhouse gas regulation under the Clean Air Act.
Dive Insight:
In 2024, the Biden administration made three substantial changes to the EPA’s Mercury and Air Toxics Standards, which set technology-based emissions standards for mercury and other hazardous air pollutants from coal- and oil-fired power plants. Its new rule strengthened emissions standards for filterable particulate matter, required coal- and oil-fired power plants to use continuous monitoring systems and required lignite-fired power plants to comply with the same standards as other coal-fired power plants.
In February, Trump’s EPA finalized the repeal of the Biden administration’s rule. “EPA continues enforcing existing, highly effective, and robust 2012 MATS rule requirements, ensuring the public health and the environment are protected without compromising America’s energy or economic prosperity,” the agency stated in a press release.
The EPA expects its action to save $670 million from 2028 through 2037 “in the form of lower costs of transportation, heating, utilities, farming, and manufacturing, and more reliable energy”
Deborah Murray, senior attorney for the Southern Environmental Law Center, said in a statement that the 2024 safeguards have significantly lowered levels of mercury, arsenic, lead and other toxic air pollutants. “Efforts by the Trump administration’s EPA to undermine this progress to promote industry-friendly policies comes at a huge cost for communities who depend on clean air,” she said.
“Maintaining the updated 2024 standards is essential to building on the proven successful track record of the MATS, which have … saved thousands of lives each year,” Georges Benjamin, CEO of the American Public Health Association, said in a statement.
Monday’s lawsuit and the February lawsuit challenging the repeal of the endangerment finding were both filed in the U.S. Court of Appeals for the District of Columbia Circuit.
The EPA said it does not comment on current or pending litigation.
