Approval and Promulgation of Air Quality Implementation Plans; Wyoming; Revisions to Regional Haze State Implementation Plan; Revisions to Regional Haze Federal Implementation Plan

The Environmental Protection Agency (EPA) is finalizing approval of State Implementation Plan (SIP) revisions submitted by the State of Wyoming on April 5, 2018, addressing regional haze. The revisions modify the sulfur dioxide (SO<INF>2</INF>) emissions reporting requirements for Laramie River Station Units 1 and 2. We are also finalizing revisions to the nitrogen oxides (NO<INF>X</INF>) emission limits for Laramie River Units 1, 2 and 3 in the Federal Implementation Plan (FIP) for regional haze in Wyoming. The revisions to the Wyoming regional haze FIP also establish a SO<INF>2</INF> emission limit averaged annually across both Laramie River Station Units 1 and 2. These units are operated by, and owned in part by, Basin Electric Power Cooperative (Basin Electric). The EPA is taking this action pursuant to section 110 of the Clean Air Act (CAA).