Supplemental Finding That It Is Appropriate and Necessary To Regulate Hazardous Air Pollutants From Coal- and Oil-Fired Electric Utility Steam Generating Units

The Environmental Protection Agency (EPA) is soliciting comment on a proposed supplemental finding that consideration of cost does not alter the agency's previous conclusion that it is appropriate and necessary to regulate coal- and oil-fired electric utility steam generating units (EGUs) under section 112 of the Clean Air Act (CAA). In light of the U.S. Supreme Court decision in Michigan v. EPA, 135 S.Ct. 2699 (2015), the EPA has taken cost into account in evaluating whether such regulation is appropriate. In this document, the EPA sets forth its proposed supplemental finding and requests comment on all aspects of that finding and the supporting legal memorandum in the docket for this action. This proposed supplemental finding, if finalized after consideration of comments, will conclude that coal- and oil-fired EGUs are properly included on the CAA section 112(c) list of sources that must be regulated under CAA section 112(d).