Approval, Disapproval and Promulgation of Implementation Plans; State of Wyoming; Regional Haze State Implementation Plan; Federal Implementation Plan for Regional Haze

The Environmental Protection Agency (EPA) is partially approving and partially disapproving a State Implementation Plan (SIP) submitted by the State of Wyoming on January 12, 2011, that addresses regional haze. This SIP was submitted to address the requirements of the Clean Air Act (CAA or "the Act") and rules that require states to address in specific ways any existing anthropogenic impairment of visibility in mandatory Class I areas caused by emissions of air pollutants from numerous sources located over a wide geographic area (also referred to as the "regional haze program"). States are required to assure reasonable progress toward the national goal of achieving natural visibility conditions in Class I areas. EPA is approving several aspects of Wyoming's regional haze SIP that we had proposed to disapprove in our June 10, 2013 proposed rule in light of public comments and newly available information indicating the adequacy of the SIP with respect to those aspects. EPA is also approving some aspects of the State's SIP that we proposed to approve. EPA is promulgating a Federal Implementation Plan (FIP) to address some of the deficiencies identified in our proposed partial disapproval of Wyoming's regional haze SIP issued on June 10, 2013. EPA is taking this action pursuant to sections 110 and 169A of the CAA.