{"abstract":"The Environmental Protection Agency (EPA) is proposing to approve the regional haze State Implementation Plan (SIP) revision submitted by the Illinois Environmental Protection Agency (Illinois EPA) on June 3, 2024, as satisfying applicable requirements under the Clean Air Act (CAA) and the EPA's Regional Haze Rule for the program's second implementation period. The EPA proposes to find that Illinois' regional haze SIP submission fulfills the requirement that States must periodically revise their long-term strategies for making reasonable progress towards the national goal of preventing any future, and remedying any existing, anthropogenic impairment of visibility in mandatory Class I Federal areas. The EPA is also proposing to approve portions of Illinois' September 29, 2017, and May 16, 2019, infrastructure SIP submissions for the 2012 fine particulate matter (PM<INF>2.5</INF>) and 2015 ozone National Ambient Air Quality Standards (NAAQS), respectively. The EPA is proposing that Illinois' infrastructure submissions fulfill CAA requirements for a State's SIP to contain adequate provisions prohibiting emissions that will interfere with required visibility protection measures in any other State's SIP.","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/2026/02/27/2026-03936.html","cfr_references":[{"chapter":null,"citation_url":null,"part":"52","title":40}],"citation":"91 FR 9779","comment_url":null,"comments_close_on":"2026-03-30","correction_of":null,"corrections":[],"dates":"Written comments must be received on or before March 30, 2026.","disposition_notes":null,"docket_ids":["EPA-R05-OAR-2017-0583","EPA-R05-OAR-2019-0311","EPA-R05-OAR-2024-0261","FRL-13083-01-R5"],"dockets":[{"supporting_documents":[{"title":"IEPA ANP 2021 Approval Letter, 10/22/2020","document_id":"EPA-R05-OAR-2017-0583-0009"},{"title":"105 Grant Final Closeout Letter IL EPA BG 98542815, 04/22/2020","document_id":"EPA-R05-OAR-2017-0583-0008"},{"title":"Illinois 2012 PM2-5 iSIP Good Neighbor Provisions, 09/29/2017 submittal","document_id":"EPA-R05-OAR-2017-0583-0002"}],"agency_name":"EPA","documents":[{"comment_count":0,"comment_start_date":"2026-02-27","updated_at":"2026-03-31T00:06:10.344-04:00","comment_url":"https://www.regulations.gov/commenton/EPA-R05-OAR-2017-0583-0012","allow_late_comments":false,"id":"EPA-R05-OAR-2017-0583-0012","comment_end_date":"2026-03-31","regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":3,"id":"EPA-R05-OAR-2017-0583","title":"Illinois 2012 PM2-5 Infrastructure SIP"},{"supporting_documents":[{"title":"IEPA ANP 2021 Approval Letter, 10/22/2020","document_id":"EPA-R05-OAR-2019-0311-0009"},{"title":"105 Grant Final Closeout Letter IL EPA BG 98542815, 04/22/2020","document_id":"EPA-R05-OAR-2019-0311-0008"},{"title":"Review of Comment on the Proposed Approval of the Illinois 2015 OzoneEmission Statement Certification","document_id":"EPA-R05-OAR-2019-0311-0007"},{"title":"Illinois 2015 Ozone Infrastructure SIP, 05/21/2019 submittal","document_id":"EPA-R05-OAR-2019-0311-0003"}],"agency_name":"EPA","documents":[{"comment_count":1,"comment_start_date":"2026-02-27","updated_at":"2026-03-31T00:06:10.016-04:00","comment_url":"https://www.regulations.gov/commenton/EPA-R05-OAR-2019-0311-0014","allow_late_comments":false,"id":"EPA-R05-OAR-2019-0311-0014","comment_end_date":"2026-03-31","regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":4,"id":"EPA-R05-OAR-2019-0311","title":"Illinois 2015 Ozone Infrastructure SIP"},{"supporting_documents":[{"title":"EPA Guidance on Infrastructure SIP Elements Sept 2013","document_id":"EPA-R05-OAR-2024-0261-0052"},{"title":"Control Cost Manual - SO2 Controls - Scrubbers","document_id":"EPA-R05-OAR-2024-0261-0051"},{"title":"Control Cost Manual - NOx Controls - SCR","document_id":"EPA-R05-OAR-2024-0261-0050"},{"title":"2019-08-20 EPA Regional Haze Guidance","document_id":"EPA-R05-OAR-2024-0261-0048"},{"title":"EPA Updated 2028 Regional Haze Modeling TSD 2019","document_id":"EPA-R05-OAR-2024-0261-0046"},{"title":"IL - 2017-04-05 Base Year Selection Workgroup Final Report","document_id":"EPA-R05-OAR-2024-0261-0045"},{"title":"IL -Midwest Electric Power-Natural Gas Fired Turbines Facility-Units CT-01 CT-02 CT-03 CT-04 CT-05-RUE-9-1-2022","document_id":"EPA-R05-OAR-2024-0261-0041"},{"title":"IL - Constellation - SE Chicago Energy Project - Units CTG5 CTG6 CTG7 CTG8 CTG9 CTG10 CTG11 CTG12 - RUE - 6-30-2024","document_id":"EPA-R05-OAR-2024-0261-0034"},{"title":"IL - CWLP - Dallman - Unit 33 - RUE - 3-1-2024","document_id":"EPA-R05-OAR-2024-0261-0033"},{"title":"IL - Tate and Lyle - Decatur - Boilers 1 and 2 aka Unit 299 - Permit - 7-31-2019","document_id":"EPA-R05-OAR-2024-0261-0028"}],"agency_name":"EPA","documents":[{"comment_count":3,"comment_start_date":"2026-02-27","updated_at":"2026-03-31T01:56:26.267-04:00","comment_url":"https://www.regulations.gov/commenton/EPA-R05-OAR-2024-0261-0001","allow_late_comments":false,"id":"EPA-R05-OAR-2024-0261-0001","comment_end_date":"2026-03-31","regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":51,"id":"EPA-R05-OAR-2024-0261","title":"Illinois Regional Haze SIP Second Implementation Period"}],"document_number":"2026-03936","effective_on":null,"end_page":9793,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2026/02/27/2026-03936.xml","html_url":"https://www.federalregister.gov/documents/2026/02/27/2026-03936/air-plan-approvals-illinois-regional-haze-plan-for-the-second-implementation-period-interstate","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2026-03936?publication_date=2026-02-27","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2026-02-27/2026-03936/mods.xml","not_received_for_publication":null,"page_length":15,"page_views":{"count":377,"last_updated":"2026-07-28 14:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2026-02-27/pdf/2026-03936.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2026-03936.pdf?1772113511","publication_date":"2026-02-27","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2026/02/27/2026-03936.txt","regulation_id_number_info":{},"regulation_id_numbers":[],"regulations_dot_gov_info":{"supporting_documents":[{"title":"EPA Guidance on Infrastructure SIP Elements Sept 2013","document_id":"EPA-R05-OAR-2024-0261-0052"},{"title":"Control Cost Manual - SO2 Controls - Scrubbers","document_id":"EPA-R05-OAR-2024-0261-0051"},{"title":"Control Cost Manual - NOx Controls - SCR","document_id":"EPA-R05-OAR-2024-0261-0050"},{"title":"2019-08-20 EPA Regional Haze Guidance","document_id":"EPA-R05-OAR-2024-0261-0048"},{"title":"EPA Updated 2028 Regional Haze Modeling TSD 2019","document_id":"EPA-R05-OAR-2024-0261-0046"},{"title":"IL - 2017-04-05 Base Year Selection Workgroup Final Report","document_id":"EPA-R05-OAR-2024-0261-0045"},{"title":"IL -Midwest Electric Power-Natural Gas Fired Turbines Facility-Units CT-01 CT-02 CT-03 CT-04 CT-05-RUE-9-1-2022","document_id":"EPA-R05-OAR-2024-0261-0041"},{"title":"IL - Constellation - SE Chicago Energy Project - Units CTG5 CTG6 CTG7 CTG8 CTG9 CTG10 CTG11 CTG12 - RUE - 6-30-2024","document_id":"EPA-R05-OAR-2024-0261-0034"},{"title":"IL - CWLP - Dallman - Unit 33 - RUE - 3-1-2024","document_id":"EPA-R05-OAR-2024-0261-0033"},{"title":"IL - Tate and Lyle - Decatur - Boilers 1 and 2 aka Unit 299 - Permit - 7-31-2019","document_id":"EPA-R05-OAR-2024-0261-0028"}],"comments_count":3,"agency_id":"EPA","comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=EPA-R05-OAR-2024-0261","supporting_documents_count":51,"docket_id":"EPA-R05-OAR-2024-0261","document_id":"EPA-R05-OAR-2024-0261-0001","regulation_id_number":null,"title":"Illinois Regional Haze SIP Second Implementation Period","checked_regulationsdotgov_at":"2026-04-01T08:55:03Z"},"regulations_dot_gov_url":null,"significant":null,"signing_date":null,"start_page":9779,"subtype":null,"title":"Air Plan Approvals; Illinois; Regional Haze Plan for the Second Implementation Period; Interstate Transport of Air Pollution for the 2012 PM2.5 and 2015 Ozone NAAQS","toc_doc":"Illinois; Interstate Transport of Air Pollution for the 2012 PM2.5 and 2015 Ozone National Ambient Air Quality Standards","toc_subject":"Air Quality State Implementation Plans; Approvals and Promulgations","topics":["Air pollution control","Environmental protection","Incorporation by reference","Nitrogen oxides","Ozone","Particulate matter","Sulfur oxides"],"type":"Proposed Rule","volume":91}