An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Mercury and Air Toxics Standards

Proposed Revised Supplemental Finding and Results of the Residual Risk and Technology Review

On December 27, 2018, EPA issued a proposed revised Supplemental Cost Finding for the Mercury and Air Toxics Standards, as well as the Clean Air Act required “risk and technology review.”  After taking account of both the cost to coal- and oil-fired power plants of complying with the MATS rule (costs that range from $7.4 to $9.6 billion annually) and the benefits attributable to regulating hazardous air pollutant (HAP) emissions from these power plants (quantifiable benefits that range from $4 to $6 million annually), as EPA was directed to do by the United States Supreme Court, the Agency proposes to determine that it is not “appropriate and necessary” to regulate HAP emissions from power plants under Section 112 of the Clean Air Act.  The emission standards and other requirements of the MATS rule, first promulgated in 2012, would remain in place, however, since EPA is not proposing to remove coal- and oil-fired power plants from the list of sources that are regulated under Section 112 of the Act.

Additional Resources

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.