{"abstract":"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 The SIP revisions include removing outdated requirements and reinstating SO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).","action":"Final rule.","agencies":[{"raw_name":"ENVIRONMENTAL PROTECTION AGENCY","name":"Environmental Protection Agency","id":145,"url":"https://www.federalregister.gov/agencies/environmental-protection-agency","json_url":"https://www.federalregister.gov/api/v1/agencies/145","parent_id":null,"slug":"environmental-protection-agency"}],"body_html_url":"https://www.federalregister.gov/documents/full_text/html/2025/09/05/2025-17028.html","cfr_references":[{"chapter":null,"citation_url":null,"part":"52","title":40},{"chapter":null,"citation_url":null,"part":"62","title":40}],"citation":"90 FR 42839","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"This final rule is effective on October 6, 2025.","disposition_notes":null,"docket_ids":["EPA-R07-OAR-2025-0263","FRL-12807-02-R7"],"dockets":[{"supporting_documents":[{"title":"SubmissionForm_10_CSR_10-6.261_to_replace_10_CSR_10-6.260_in_Missouri_SIP_submit.html","document_id":"EPA-R07-OAR-2025-0263-0006"},{"title":"SubmissionForm_MO_Rule_amendment_10_CSR_10-6.261_03072019_submit.html","document_id":"EPA-R07-OAR-2025-0263-0005"},{"title":"MO-477 6.261 TSD","document_id":"EPA-R07-OAR-2025-0263-0004"},{"title":"2022-05-04-negative-declaration-sulfuric-acid-production-plants","document_id":"EPA-R07-OAR-2025-0263-0003"},{"title":"6.261 EPA Submittal with cover letter and attachments","document_id":"EPA-R07-OAR-2025-0263-0002"}],"agency_name":"EPA","documents":[{"comment_count":0,"comment_start_date":"2025-09-05","updated_at":"2025-09-05T09:57:58.819-04:00","comment_url":"https://www.regulations.gov/commenton/EPA-R07-OAR-2025-0263-0007","allow_late_comments":false,"id":"EPA-R07-OAR-2025-0263-0007","comment_end_date":null,"regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":5,"id":"EPA-R07-OAR-2025-0263","title":"Air Plan Approval; Missouri; Control of Sulfur Dioxide Emissions and  Approval and Promulgation of State Plan (Negative Declaration) for Designated Facilities and Pollutants"}],"document_number":"2025-17028","effective_on":"2025-10-06","end_page":42841,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2025/09/05/2025-17028.xml","html_url":"https://www.federalregister.gov/documents/2025/09/05/2025-17028/air-plan-approval-missouri-control-of-sulfur-dioxide-emissions-and-approval-and-promulgation-of","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2025-17028?publication_date=2025-09-05","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2025-09-05/2025-17028/mods.xml","not_received_for_publication":null,"page_length":3,"page_views":{"count":201,"last_updated":"2026-10-25 06:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2025-09-05/pdf/2025-17028.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2025-17028.pdf?1756989913","publication_date":"2025-09-05","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2025/09/05/2025-17028.txt","regulation_id_number_info":{},"regulation_id_numbers":[],"regulations_dot_gov_info":{"supporting_documents":[{"title":"SubmissionForm_10_CSR_10-6.261_to_replace_10_CSR_10-6.260_in_Missouri_SIP_submit.html","document_id":"EPA-R07-OAR-2025-0263-0006"},{"title":"SubmissionForm_MO_Rule_amendment_10_CSR_10-6.261_03072019_submit.html","document_id":"EPA-R07-OAR-2025-0263-0005"},{"title":"MO-477 6.261 TSD","document_id":"EPA-R07-OAR-2025-0263-0004"},{"title":"2022-05-04-negative-declaration-sulfuric-acid-production-plants","document_id":"EPA-R07-OAR-2025-0263-0003"},{"title":"6.261 EPA Submittal with cover letter and attachments","document_id":"EPA-R07-OAR-2025-0263-0002"}],"comments_count":0,"agency_id":"EPA","comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=EPA-R07-OAR-2025-0263","supporting_documents_count":5,"docket_id":"EPA-R07-OAR-2025-0263","document_id":"EPA-R07-OAR-2025-0263-0007","regulation_id_number":null,"title":"Air Plan Approval; Missouri; Control of Sulfur Dioxide Emissions and  Approval and Promulgation of State Plan (Negative Declaration) for Designated Facilities and Pollutants","checked_regulationsdotgov_at":"2025-09-06T16:55:03Z"},"regulations_dot_gov_url":null,"significant":null,"signing_date":null,"start_page":42839,"subtype":null,"title":"Air Plan Approval; Missouri; Control of Sulfur Dioxide Emissions and Approval and Promulgation of State Plan (Negative Declaration) for Designated Facilities and Pollutants","toc_doc":"Missouri; Control of Sulfur Dioxide Emissions and Approval and Promulgation of State Plan (Negative Declaration) for Designated Facilities and Pollutants","toc_subject":"Air Quality State Implementation Plans; Approvals and Promulgations","topics":["Administrative practice and procedure","Air pollution control","Carbon monoxide","Environmental protection","Incorporation by reference","Intergovernmental relations","Lead","Nitrogen dioxide","Ozone","Particulate matter","Reporting and recordkeeping requirements","Sulfur oxides","Volatile organic compounds"],"type":"Rule","volume":90}