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 proposing to approve a State Implementation Plan (SIP) revision submitted by the State of Wyoming on April 5, 2018, addressing regional haze. The revisions modify the sulfur dioxide (SO2) emissions reporting requirements for Laramie River Station Units 1 and 2. We are also proposing to revise the nitrogen oxides (NOX) best available retrofit technology (BART) emission limits for Laramie River Units 1-3 in the Federal Implementation Plan (FIP) for regional haze in Wyoming. The proposed revisions to the Wyoming regional haze FIP would also establish a SO2 emission limit averaged annually across both Laramie River Station Units 1 and 2. The EPA is proposing this action pursuant to section 110 of the Clean Air Act (CAA).