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

Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Environmental Protection Agency 40 CFR Parts 52 and 62 [EPA-R07-OAR-2025-0263; FRL-12807-02-R7] ( printed page 42839) AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: 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 2 ) rule with the latest version of a newer SO 2 rule (10 CSR 10-6.261). The SIP revisions include removing outdated requirements and reinstating SO 2 emission limits for the Ameren-Labadie and Evergy-Hawthorn power plants.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). DATES: This final rule is effective on October 6, 2025. ADDRESSES: The EPA has established a docket for this action under Docket ID No. EPA-R07-OAR-2025-0263. All documents in the docket are listed on the https://www.regulations.gov website. Although listed in the index, some information is not publicly available, i.e., Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed…