{"abstract":"The Environmental Protection Agency (EPA) proposes to approve an August 20, 2024 request by the Oregon Department of Environmental Quality (Oregon) to revise the attainment plan for the Klamath Falls, Oregon, nonattainment area; redesignate the Klamath Falls nonattainment area to attainment for the 2006 24-hour fine particulate matter (PM<INF>2.5</INF>) National Ambient Air Quality Standard (NAAQS); and approve into the Oregon state implementation plan (SIP) a maintenance plan for the area that demonstrates continued attainment through 2037. This proposed rulemaking includes approving the motor vehicle emission budget for the area and approving updated state rules and the Klamath County Clean Air Ordinance, to be incorporated by reference. EPA proposes these actions pursuant to the Clean Air Act (CAA or the Act).","action":"Proposed 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/2026/03/04/2026-04333.html","cfr_references":[{"chapter":null,"citation_url":null,"part":"52","title":40},{"chapter":null,"citation_url":null,"part":"81","title":40}],"citation":"91 FR 10545","comment_url":null,"comments_close_on":"2026-04-03","correction_of":null,"corrections":[],"dates":"Comments must be received on or before April 3, 2026.","disposition_notes":null,"docket_ids":["EPA-R10-OAR-2025-0052","FRL-12592-01-R10"],"dockets":[{"supporting_documents":[{"title":"120925_KFALLS Maintenance Plan Clarifiaction Letter","document_id":"EPA-R10-OAR-2025-0052-0025"},{"title":"Attachment 2 KFALLS-OARs","document_id":"EPA-R10-OAR-2025-0052-0024"},{"title":"Attachment 7 KFalls Ordinance","document_id":"EPA-R10-OAR-2025-0052-0023"},{"title":"Attachment 1 KFALLS-EQC Report","document_id":"EPA-R10-OAR-2025-0052-0022"},{"title":"20250402_AQ_KFALLS-MSIP_CoverLetter (Signed)","document_id":"EPA-R10-OAR-2025-0052-0021"},{"title":"Attachment 6 KFalls-Email Notice","document_id":"EPA-R10-OAR-2025-0052-0020"},{"title":"KlamathFalls.RedesignationRequest.SIP_.CoverLetter (part 1) - signed","document_id":"EPA-R10-OAR-2025-0052-0019"},{"title":"Klamath Falls 2006 24-hour PM2.5 Maintenance Plan and Resignation Request","document_id":"EPA-R10-OAR-2025-0052-0018"},{"title":"Attachment 3","document_id":"EPA-R10-OAR-2025-0052-0017"},{"title":"OR_2024_ANP_Response_Final","document_id":"EPA-R10-OAR-2025-0052-0016"}],"agency_name":"EPA","documents":[{"comment_count":4,"comment_start_date":"2026-03-04","updated_at":"2026-04-04T01:56:39.009-04:00","comment_url":"https://www.regulations.gov/commenton/EPA-R10-OAR-2025-0052-0003","allow_late_comments":false,"id":"EPA-R10-OAR-2025-0052-0003","comment_end_date":"2026-04-04","regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":23,"id":"EPA-R10-OAR-2025-0052","title":"Klamath Falls 2006 24-hour PM2.5 NAAQS Redesignation"}],"document_number":"2026-04333","effective_on":null,"end_page":10556,"executive_order_notes":null,"executive_order_number":null,"explanation":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2026/03/04/2026-04333.xml","html_url":"https://www.federalregister.gov/documents/2026/03/04/2026-04333/air-plan-approval-or-klamath-falls-pm25-redesignation-to-attainment-and-maintenance-plan","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2026-04333?publication_date=2026-03-04","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2026-03-04/2026-04333/mods.xml","not_received_for_publication":null,"page_length":12,"page_views":{"count":274,"last_updated":"2026-05-10 10:15:10 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2026-03-04/pdf/2026-04333.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2026-04333.pdf?1772545529","publication_date":"2026-03-04","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2026/03/04/2026-04333.txt","regulation_id_number_info":{},"regulation_id_numbers":[],"regulations_dot_gov_info":{"supporting_documents":[{"title":"120925_KFALLS Maintenance Plan Clarifiaction Letter","document_id":"EPA-R10-OAR-2025-0052-0025"},{"title":"Attachment 2 KFALLS-OARs","document_id":"EPA-R10-OAR-2025-0052-0024"},{"title":"Attachment 7 KFalls Ordinance","document_id":"EPA-R10-OAR-2025-0052-0023"},{"title":"Attachment 1 KFALLS-EQC Report","document_id":"EPA-R10-OAR-2025-0052-0022"},{"title":"20250402_AQ_KFALLS-MSIP_CoverLetter (Signed)","document_id":"EPA-R10-OAR-2025-0052-0021"},{"title":"Attachment 6 KFalls-Email Notice","document_id":"EPA-R10-OAR-2025-0052-0020"},{"title":"KlamathFalls.RedesignationRequest.SIP_.CoverLetter (part 1) - signed","document_id":"EPA-R10-OAR-2025-0052-0019"},{"title":"Klamath Falls 2006 24-hour PM2.5 Maintenance Plan and Resignation Request","document_id":"EPA-R10-OAR-2025-0052-0018"},{"title":"Attachment 3","document_id":"EPA-R10-OAR-2025-0052-0017"},{"title":"OR_2024_ANP_Response_Final","document_id":"EPA-R10-OAR-2025-0052-0016"}],"comments_count":4,"agency_id":"EPA","comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=EPA-R10-OAR-2025-0052","supporting_documents_count":23,"docket_id":"EPA-R10-OAR-2025-0052","document_id":"EPA-R10-OAR-2025-0052-0003","regulation_id_number":null,"title":"Klamath Falls 2006 24-hour PM2.5 NAAQS Redesignation","checked_regulationsdotgov_at":"2026-04-05T08:55:04Z"},"regulations_dot_gov_url":null,"significant":null,"signing_date":null,"start_page":10545,"subtype":null,"title":"Air Plan Approval; OR; Klamath Falls PM2.5 Redesignation to Attainment and Maintenance Plan","toc_doc":"Oregon; Klamath Falls PM2.5 Redesignation to Attainment and Maintenance Plan","toc_subject":"Air Quality State Implementation Plans; Approvals and Promulgations","topics":["Air pollution control","Carbon monoxide","Environmental protection","Incorporation by reference","Intergovernmental relations","Lead","Ozone","Reporting and recordkeeping requirements","Sulfur oxides","Volatile organic compounds"],"type":"Proposed Rule","volume":91}