Approval and Promulgation of Implementation Plans; Wyoming; Revisions to SO2

The Environmental Protection Agency (EPA) is taking direct final action to approve changes to Wyoming's State Implementation Plan (SIP) that update its ambient air quality standards with regard to the 1-hour sulfur dioxide (SO2) and secondary SO2 National Ambient Air Quality Standards (NAAQS). On February 7, 2014, the Wyoming Department of Environmental Quality (WDEQ) submitted to EPA revisions to the Wyoming SIP. Specifically, the State revised Wyoming Air Quality Standards and Regulations (WAQSR) Chapter 2, Section 4, ``Ambient standards for sulfur oxides.'' In this action, EPA is taking direct final action to approve some of the revisions provided in that SIP submission. This action is being taken in accordance with section 110 of the Clean Air Act (CAA).