EPA repealed Mercury and Air Toxics Standards for coal- and oil-fired power plants, again declining to monetize health benefits

On February 24, 2026, the U.S. Environmental Protection Agency under Administrator Lee Zeldin published a final rule repealing the 2024 Mercury and Air Toxics Standards (MATS) amendments for coal- and oil-fired power plants, first adopted under the Obama administration in 2012 and strengthened in 2024. The rule eliminated tightened emissions limits for mercury, lead, arsenic, chromium, nickel, and cadmium, and removed a requirement that plants install continuous emissions monitoring systems. EPA justified the repeal by pointing to a 2020 residual-risk review that found cancer risk from the affected pollutants was already below a "presumptive acceptable" threshold, concluding no further reduction was "necessary" -- without citing new data from the intervening years to support reopening that 2020 finding now.

As it had five weeks earlier in a separate rule for stationary combustion and gas turbines, EPA's cost-benefit analysis for the MATS repeal did not assign a dollar value to the health benefits of the mercury and toxic-pollutant reductions the standards had achieved -- benefits that include reduced cancer, cardiovascular disease, respiratory illness, and, for mercury specifically, protection of fetal and infant brain development. The agency's fact sheet presented only the projected cost savings to industry: "$670 million" in present value through 2037, or "at least $78 million annually." Mercury emissions from coal plants had fallen nearly 90% between 2012, when MATS first took effect, and 2021.

Environmental and public-health groups said the repeal discarded a settled, working protection. "Mercury and other toxic air pollutants don't just disappear -- they accumulate in our communities, our food, and our children," said Ellen Kurlansky, a former EPA Office of Air and Radiation policy analyst. Advocates noted that affected plants, hundreds of them across 45 states, had largely already installed the pollution controls MATS required, so the repeal's practical effect was to relieve plants of monitoring and compliance obligations for controls many already operate.

Updates

2026-03-30 — Coalition of 21 groups sued EPA in the D.C. Circuit over the repeal [5]

Earthjustice, on behalf of a coalition including the Environmental Defense Fund, Natural Resources Defense Council, Sierra Club, American Lung Association, American Academy of Pediatrics, American Public Health Association, and 14 other environmental and public-health organizations, filed suit in the U.S. Court of Appeals for the D.C. Circuit challenging the MATS repeal, arguing it "violates the Clean Air Act, ignores the scientific record, and abandons safeguards" and separately challenging the removal of continuous emissions monitoring requirements.