Energy & environment · 10/04/2026
Air Plan Approvals; Indiana; Prong 4 (Visibility) for the 2015 Ozone National Ambient Air Quality Standard
The Environmental Protection Agency (EPA) is proposing to approve a portion of Indiana's State Implementation Plan (SIP) submission regarding the infrastructure requirements of section 110 of the Clean Air Act (CAA) for the 2015 ozone National Ambient Air Quality Standards (NAAQS). The EPA is proposing that Indiana's infrastructure submission fulfills CAA requirements for visibility protection measures.