Air Plan Approval; Michigan; Redesignation of the Detroit, MI Area to Attainment of the 2015 Ozone Standards

The Environmental Protection Agency (EPA) is proposing to approve a request from the Michigan Department of Environment, Great Lakes, and Energy (EGLE) to redesignate the Detroit, Michigan area to attainment for the 2015 ozone National Ambient Air Quality Standards (NAAQS) because the request meets the statutory requirements for redesignation under the Clean Air Act (CAA). EGLE submitted this request on January 3, 2022, and submitted a supplement to this request on May 18, 2026. The EPA is also proposing to approve, as a revision to the Michigan State Implementation Plan (SIP), the State's updated maintenance plan for the 2015 ozone NAAQS through 2040 in the Detroit area, including motor vehicle emissions budgets for 2035 and 2040, for both volatile organic compound (VOC) and oxides of nitrogen (NO<INF>X</INF>). The EPA is also initiating the adequacy process for these maintenance plan budgets. Additionally, the EPA is proposing to adjust the SIP submission and control measure implementation deadlines for certain Moderate requirements. Finally, the EPA is proposing to take final agency action on an exceptional events request submitted by EGLE on April 15, 2026, and concurred on by the EPA on June 4, 2026.