Proposed rule · 2026-12543

Air Plan Approval; Colorado; RACT Requirements for the 2008 8-Hour Ozone Standard for the Denver Metro/North Front Range Nonattainment Area

The U.S. Environmental Protection Agency (EPA) is proposing to approve portions of Colorado State Implementation Plan (SIP) submittals under the Clean Air Act (CAA) that address SIP obligations related to Reasonably Available Control Technology (RACT) requirements for the 2008 ozone National Ambient Air Quality Standards (NAAQS) for the Denver-Boulder-Greeley-Ft. Collins-Loveland, Colorado ozone nonattainment area. The EPA is proposing approval of portions of the RACT SIP submittals that address reporting requirements for certain source categories and reorganize certain state air pollution regulations. The EPA is also proposing to find that the State has addressed the EPA's prior limited disapproval.