Proposed rule · 2026-11436

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

The U.S. Environmental Protection Agency (EPA) is proposing revisions to the Federal Implementation Plan (FIP) addressing regional haze in the State of Wyoming. The EPA is proposing revisions to the FIP's nitrogen oxides (NO<INF>X</INF>) best available retrofit technology (BART) requirements for the PacifiCorp Dave Johnston Power Plant Unit 3. In response to PacifiCorp's letter no longer consenting to closure of Dave Johnston Unit 3, the EPA is proposing to withdraw the NO<INF>X</INF> BART determination containing the closure requirement. Additionally, in response to a request from PacifiCorp, and in light of new information that was not available at the time the EPA originally promulgated the FIP in 2014, the Agency is also proposing to revise the other NO<INF>X</INF> BART determination for Dave Johnston Unit 3.