Air Plan Approval; Montana; Revisions to Regional Haze State Implementation Plan and Partial Withdrawals to Regional Haze Federal Implementation Plan

Publication Date: 
Friday, September 9, 2022 - 4:00am

The Environmental Protection Agency (EPA) is proposing to approve a State Implementation Plan (SIP) revision submitted by the State of Montana on March 25, 2020, addressing regional haze. Specifically, EPA is proposing to approve a SIP revision for the first implementation period of the Clean Air Act's (CAA) regional haze program that addresses the nitrogen oxides (NO<INF>X</INF>) and sulfur dioxide (SO<INF>2</INF>) Best Available Retrofit Technology (BART) requirements for two electric generating unit (EGU) facilities, as well as proposing to withdraw portions of the Federal Implementation Plan (FIP) promulgated by EPA in 2012 (2012 regional haze FIP) addressing the NO<INF>X</INF>, SO<INF>2</INF> and particulate matter (PM) BART requirements for two cement kilns and the PM BART requirements for the same two EGU facilities. This action also addresses the United States Court of Appeals for the Ninth Circuit's June 9, 2015 vacatur and remand of portions of the FIP. EPA is proposing this action pursuant to sections 110 and 169A of the CAA.

Environmental Protection Agency