February 17, 2023

WASHINGTON – Today, EPA is reaffirming the scientific, economic, and legal underpinnings of the 2012 Mercury and Air Toxics Standards (MATS) for power plants, which required significant reductions of mercury, acid gases, and other harmful pollutants. Controlling these emissions improves public health by reducing fatal heart attacks, reducing cancer risks, avoiding neurodevelopmental delays in children, and helping protect our environment. These public health protections are especially important for anyone affected by hazardous air pollution, including children and particularly vulnerable segments of the population such as Indigenous communities, low-income communities, and people of color who live near power plants.

The final rule, which responds to President Biden’s January 20, 2021, Executive Order 13990, “Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis,” reverses a rule issued by the previous administration in May 2020, which undermined the legal basis for these vital health protections. Reaffirming the science behind these clean air standards advances the Biden-Harris Administration’s whole-of-government commitment to environmental justice.

“For years, Mercury and Air Toxics Standards have protected the health of American communities nationwide, especially children, low-income communities, and communities of color who often and unjustly live near power plants,” said EPA Administrator Michael S. Regan. “This finding ensures the continuation of these critical, life-saving protections while advancing President Biden’s commitment to making science-based decisions and protecting the health and wellbeing of all people and all communities.”

The final rule leaves the current emissions standards unchanged and ensures the continuation of public health protections provided by these requirements. When weighing the substantial burden that hazardous air pollutants, including mercury, impose on public health against the reasonable costs of controlling these emissions, EPA finds that it is appropriate and necessary to regulate emissions of air toxics from power plants under the Clean Air Act. The Agency is also continuing to consider the MATS Risk and Technology Review, as directed by Executive Order 13990, to determine whether more stringent protections for hazardous air pollution from power plants are feasible and warranted and expects to address that review in a separate action.

The initial appropriate and necessary finding was made in 2000 and affirmed in 2012 and 2016. In May 2020, the previous administration reversed EPA’s 2016 finding, undermining the legal basis for the Mercury and Air Toxics Standards. President Biden’s Executive Order 13990 directed EPA to review that finding and consider an action to rescind it. In today’s action, EPA finds that the 2020 action was based on a fundamentally flawed interpretation of the Clean Air Act that improperly ignored or undervalued vital health benefits from reducing hazardous air pollution from power plants. Based on a thorough review of these benefits, the reasonable costs of controls, and other relevant factors, EPA reaffirms that it is appropriate and necessary to regulate emissions of hazardous air pollutants from coal- and oil-fired power plants.

The MATS, combined with advancements in the power sector, have driven sharp reductions in harmful pollutants. EPA has estimated that by 2017, mercury emissions from power plants were reduced by 86 percent, acid gas emissions were reduced by 96 percent, and non-mercury metal emissions were reduced by 81 percent compared to pre-MATS levels in 2010. After a reassessment of costs now that the MATS has been implemented, EPA concludes that the cost for the power sector to comply with the MATS was likely billions of dollars lower than originally estimated. 

Prior to the MATS, coal- and oil-fired power plants were by far the largest domestic source of mercury and other toxic pollutants such as hydrogen chloride and selenium. They were also among the largest domestic emitters of arsenic, chromium, cobalt, nickel, hydrogen cyanide, beryllium, and cadmium.

Learn more at Mercury and Air Toxics Standards.

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