For more information on MATS please see our new white paper Rolling Back the Mercury and Air Toxics Standards: Proposed Withdrawal of “Appropriate and Necessary”, our MATS Rollback Tracker post, and our CleanLaw podcast with Kathy Fallon Lambert.
February 16, 2012 – EPA Mercury and Air Toxics Standards Final Rule:
- Finds that it’s “appropriate and necessary” to regulate hazardous air pollutants from power plants under Section 112 of the Clean Air Act
- Sets pollution control standards for hazardous air pollutants from power plants
June 29, 2015 – Michigan v. EPA, Supreme Court:
- Rules that EPA improperly failed to consider cost in making the MATS “appropriate and necessary” finding
December 15, 2015 – D.C. Circuit Court of Appeals:
- Denies a motion to stay MATS
- Remands to EPA consideration of costs in determining whether it is appropriate and necessary to regulate power plant emissions under Section 112
April 25, 2016 – EPA Supplemental Appropriate and Necessary Finding:
- Confirms that after considering costs it remains necessary to regulate power plant emissions under Section 112.
July 10, 2018 – Utility Industry and Other Stakeholders:
- Report to EPA that industry has been in full compliance with MATS since April 2016
February 7, 2019 – EPA Reconsideration of Appropriate and Necessary Finding:
- Proposes withdrawal of appropriate and necessary finding and retention of pollution control standards
- Requests comment on whether withdrawal of appropriate and necessary finding authorizes EPA to rescind the MATS pollution control requirements