{"abstract":"The U.S. Environmental Protection Agency (EPA) is revising the Original 2013 Federal Implementation Plan (FIP) by finalizing nitrogen oxide (NO<INF>X</INF>) emission limits for the indurating furnace at United States Steel's (U.S. Steel) Keetac taconite facility (Keetac) in Keewatin, Minnesota to satisfy the requirement for best available retrofit technology (BART) at taconite facilities. The EPA is finalizing the following NO<INF>X</INF> BART emission limits for the Keetac Grate Kiln indurating furnace, with compliance to be determined on a rolling 720-hour average: 3.4 pounds (lbs) of NO<INF>X</INF> per million British Thermal Unit (MMBtu) when firing exclusively natural gas, which will become enforceable beginning three years after promulgation of a final rule; and 2.0 lbs NO<INF>X</INF>/MMBtu when firing any fuel or combination of fuels other than exclusively natural gas, which will become enforceable five years after promulgation of a final rule, unless before that date the EPA promulgates a modified limit. The final rule allows Keetac, within a period of 52 months from the effective date of the final rule, the option to seek a potential adjustment of the cofiring emission limit, not to exceed 2.5 lbs NO<INF>X</INF>/MMBtu as a 720-hour rolling average, based on collection of continuous emission monitoring system (CEMS) data after installation of the NO<INF>X</INF> reduction technology.","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/2026/06/08/2026-11432.html","cfr_references":[{"chapter":null,"citation_url":null,"part":"52","title":40}],"citation":"91 FR 34574","comment_url":null,"comments_close_on":null,"correction_of":null,"corrections":[],"dates":"This final rule is effective on July 8, 2026.","disposition_notes":null,"docket_ids":["EPA-R05-OAR-2024-2016","FRL-12599-02-R5"],"dockets":[{"supporting_documents":[{"title":"2024-4-23 Keetac 113g settlement proposed FRN","document_id":"EPA-R05-OAR-2024-0216-0042"},{"title":"2022-1-01 - 2023-5-20 Keetac fuel and prod data","document_id":"EPA-R05-OAR-2024-0216-0041"},{"title":"2020-10-16 USS email re Fives and FCT","document_id":"EPA-R05-OAR-2024-0216-0040"},{"title":"2019-8-26 USS proposed solid fuel limit justification email","document_id":"EPA-R05-OAR-2024-0216-0036"},{"title":"2019-2-08 Metso Keetac Water Injection Analysis study","document_id":"EPA-R05-OAR-2024-0216-0031"},{"title":"2018-8-08 Keetac Line II LNB technical analysis","document_id":"EPA-R05-OAR-2024-0216-0029"},{"title":"2018-5-24 USS Keetac proposal","document_id":"EPA-R05-OAR-2024-0216-0028"},{"title":"2018-8-03 USS Response to EPA Questions from June 8 2018","document_id":"EPA-R05-OAR-2024-0216-0027"},{"title":"2017-8-17 USS Keetac Final Temperature Report submittal","document_id":"EPA-R05-OAR-2024-0216-0024"},{"title":"2017-6-6 US Steel Response to EPA 114- Submittal","document_id":"EPA-R05-OAR-2024-0216-0023"}],"agency_name":"EPA","documents":[{"comment_count":0,"comment_start_date":"2026-06-08","updated_at":"2026-06-08T16:01:57.836-04:00","comment_url":"https://www.regulations.gov/commenton/EPA-R05-OAR-2024-0216-0047","allow_late_comments":false,"id":"EPA-R05-OAR-2024-0216-0047","comment_end_date":null,"regulations_dot_gov_open_for_comment":false}],"supporting_documents_count":42,"id":"EPA-R05-OAR-2024-0216","title":"Revision to Minnesota Taconite FIP for U.S. Steel Keetac"}],"document_number":"2026-11432","effective_on":"2026-07-08","end_page":34582,"executive_order_notes":null,"executive_order_number":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2026/06/08/2026-11432.xml","html_url":"https://www.federalregister.gov/documents/2026/06/08/2026-11432/air-plan-approval-minnesota-revision-to-taconite-federal-implementation-plan","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2026-11432?publication_date=2026-06-08","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2026-06-08/2026-11432/mods.xml","not_received_for_publication":null,"page_length":9,"page_views":{"count":237,"last_updated":"2026-06-22 20:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2026-06-08/pdf/2026-11432.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2026-11432.pdf?1780663515","publication_date":"2026-06-08","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2026/06/08/2026-11432.txt","regulation_id_number_info":{},"regulation_id_numbers":[],"regulations_dot_gov_info":{"supporting_documents":[{"title":"2024-4-23 Keetac 113g settlement proposed FRN","document_id":"EPA-R05-OAR-2024-0216-0042"},{"title":"2022-1-01 - 2023-5-20 Keetac fuel and prod data","document_id":"EPA-R05-OAR-2024-0216-0041"},{"title":"2020-10-16 USS email re Fives and FCT","document_id":"EPA-R05-OAR-2024-0216-0040"},{"title":"2019-8-26 USS proposed solid fuel limit justification email","document_id":"EPA-R05-OAR-2024-0216-0036"},{"title":"2019-2-08 Metso Keetac Water Injection Analysis study","document_id":"EPA-R05-OAR-2024-0216-0031"},{"title":"2018-8-08 Keetac Line II LNB technical analysis","document_id":"EPA-R05-OAR-2024-0216-0029"},{"title":"2018-5-24 USS Keetac proposal","document_id":"EPA-R05-OAR-2024-0216-0028"},{"title":"2018-8-03 USS Response to EPA Questions from June 8 2018","document_id":"EPA-R05-OAR-2024-0216-0027"},{"title":"2017-8-17 USS Keetac Final Temperature Report submittal","document_id":"EPA-R05-OAR-2024-0216-0024"},{"title":"2017-6-6 US Steel Response to EPA 114- Submittal","document_id":"EPA-R05-OAR-2024-0216-0023"}],"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-R05-OAR-2024-0216","supporting_documents_count":42,"docket_id":"EPA-R05-OAR-2024-0216","document_id":"EPA-R05-OAR-2024-0216-0047","regulation_id_number":null,"title":"Revision to Minnesota Taconite FIP for U.S. Steel Keetac","checked_regulationsdotgov_at":"2026-06-09T16:31:49Z"},"regulations_dot_gov_url":null,"significant":null,"signing_date":null,"start_page":34574,"subtype":null,"title":"Air Plan Approval; Minnesota; Revision to Taconite Federal Implementation Plan","toc_doc":"Minnesota; Revision to Taconite Federal Implementation Plan","toc_subject":"Air Quality State Implementation Plans; Approvals and Promulgations","topics":["Air pollution control","Environmental protection","Incorporation by reference","Intergovernmental relations","Nitrogen oxides","Reporting and recordkeeping requirements","Sulfur oxides"],"type":"Rule","volume":91}