{"abstract":"The Environmental Protection Agency (EPA) is taking final action to approve a State Implementation Plan (SIP) revision submitted by the State of Missouri on November 12, 2019, revising the maintenance plan demonstrating continued maintenance of the 1997 PM<INF>2.5</INF> National Ambient Air Quality Standards (NAAQS) in the St. Louis area. This revision demonstrates that the St. Louis area no longer needs to rely on the vehicle Inspection and Maintenance (I/M) program and the use of Reformulated Gasoline (RFG) for continued maintenance throughout the maintenance period for the 1997 PM<INF>2.5</INF> NAAQS. The EPA has determined that this revision meets 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/2021/09/30/2021-20972.html","cfr_references":[{"chapter":null,"citation_url":null,"part":"52","title":40}],"citation":"86 FR 54106","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"This final rule is effective on November 1, 2021.","disposition_notes":null,"docket_ids":["EPA-R07-OAR-2021-0405","FRL-8708-02-R7"],"dockets":[],"document_number":"2021-20972","effective_on":"2021-11-01","end_page":54107,"executive_order_notes":null,"executive_order_number":null,"explanation":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2021/09/30/2021-20972.xml","html_url":"https://www.federalregister.gov/documents/2021/09/30/2021-20972/air-plan-approval-approval-of-missouri-air-quality-implementation-plans-revisions-to-st-louis-1997","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2021-20972?publication_date=2021-09-30","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2021-09-30/2021-20972/mods.xml","not_received_for_publication":null,"page_length":2,"page_views":{"count":93,"last_updated":"2026-05-27 12:15:05 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2021-09-30/pdf/2021-20972.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2021-20972.pdf?1632919521","publication_date":"2021-09-30","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2021/09/30/2021-20972.txt","regulation_id_number_info":{},"regulation_id_numbers":[],"regulations_dot_gov_info":{"supporting_documents":[{"title":"Email RE_ Clarification on Rules in the 2008 Ozone and 1997 PM Maintenance Plans","document_id":"EPA-R07-OAR-2021-0405-0005"},{"title":"Clarification on Rules in 2008 Ozone and 1997 PM Maintenance Plans","document_id":"EPA-R07-OAR-2021-0405-0004"},{"title":"EPA Comment Letter Sept 5 2019 date stamped","document_id":"EPA-R07-OAR-2021-0405-0003"},{"title":"EPA submittal-STL PM Maintenance Plan Revision","document_id":"EPA-R07-OAR-2021-0405-0002"}],"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-2021-0405","supporting_documents_count":4,"docket_id":"EPA-R07-OAR-2021-0405","document_id":"EPA-R07-OAR-2021-0405-0006","regulation_id_number":null,"title":"Air Plan Approval; Approval of Missouri Air Quality Implementation Plans; Revisions to St. Louis 1997 PM2.5 Maintenance Plan","checked_regulationsdotgov_at":"2021-10-01T03:30:10Z"},"regulations_dot_gov_url":null,"significant":null,"signing_date":null,"start_page":54106,"subtype":null,"title":"Air Plan Approval; Approval of Missouri Air Quality Implementation Plans; Revisions to St. Louis 1997 PM2.5 Maintenance Plan","toc_doc":"Missouri; Air Quality Implementation Plans; Revisions to St. Louis 1997 PM2.5 Maintenance Plan","toc_subject":"Air Quality State Implementation Plans; Approvals and Promulgations:\n","topics":["Air pollution control","Environmental protection","Incorporation by reference"],"type":"Rule","volume":86}