Final rule · 2025-17028

Air Plan Approval; Missouri; Control of Sulfur Dioxide Emissions and Approval and Promulgation of State Plan (Negative Declaration) for Designated Facilities and Pollutants

The Environmental Protection Agency (EPA) is taking final action to approve revisions to the Missouri State Implementation Plan (SIP) related to replacing the previous statewide sulfur dioxide (SO<INF>2</INF>) rule with the latest version of a newer SO<INF>2</INF> rule (10 CSR 10-6.261). The SIP revisions include removing outdated requirements and reinstating SO<INF>2</INF> emission limits for the Ameren-Labadie and Evergy-Hawthorn power plants. The revisions do not impact the stringency of the SIP, nor do they impact the state's ability to attain or maintain the National Ambient Air Quality Standards (NAAQS). The EPA is also approving Missouri's negative declaration of sources subject to sulfuric acid production requirements. This final approval action is being done in accordance with the requirements of the Clean Air Act (CAA).