An official website of the United States government.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.


Enforcement Response Policy: Mercury and Air Toxics Standard (MATS)

Pursuant to Section 112 of the Clean Air Act ("CAA''), the EPA finalized national emission standards for hazardous air pollutants (''NESHAP") from electric generating units ("EGUs") in December 2011. These standards, commonly known as the "Mercury and Air Toxics Standards" ("MATS"), adopt emission limits on mercury, acid gases and other toxic pollutants for affected coal and oil-fired EGUs. 

The Mercury and Air Toxics (MATS) Enforcement Response policy (Dec. 16, 2011) describes the approach regarding the issue of Section 113(a) administrative orders with respect to the sources that must operate in noncompliance with the MATS for up to a year to address specific documented reliability concerns.

On April 16, 2016, five administrative orders were issued in connection the policy.

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