Proposed rule · 2026-02842

Air Plan Approval; Illinois; Moderate Attainment Plan Elements for the Chicago and Metro East Areas for the 2015 Ozone Standard

The Environmental Protection Agency (EPA) is proposing to approve portions of Illinois' 2015 ozone National Ambient Air Quality Standard (NAAQS or standard) Moderate nonattainment area State Implementation Plan (SIP) submission for the Chicago and the Metro East St. Louis areas. The portions of the SIP submission that the EPA is proposing to approve are the reasonable further progress (RFP) demonstration including the associated motor vehicle emissions budgets for 2023, the motor vehicle inspection and maintenance (I/M) program, the nonattainment new source review (NNSR) program, and the updated 2017 base year emissions inventories. The EPA is proposing to approve these portions of the State's SIP submission pursuant to section 110 and part D of the Clean Air Act (CAA), and the EPA's regulations. The EPA is also initiating the adequacy process for the 2023 motor vehicle emissions budgets (budgets) for the Chicago and Metro East St. Louis Moderate ozone nonattainment RFP demonstration included in this SIP submission.