{"abstract":"The U.S. Environmental Protection Agency (EPA or Agency) has received a complete Underground Injection Control (UIC) primacy application from the State of Colorado, requesting primary enforcement responsibility (primacy) for Class VI injection wells under the Safe Drinking Water Act (SDWA) section 1422. The EPA's approval of the State's UIC program primacy application would allow Colorado's Energy and Carbon Management Commission (ECMC) to issue and enforce compliance with UIC Class VI permits for injection wells used for geologic carbon sequestration. In this action, the EPA proposes to approve Colorado's application to implement the UIC program for Class VI injection wells located within the State, except those on Indian lands for which the EPA retains primacy. The EPA has determined that Colorado's UIC Class VI program meets federal requirements for primacy under SDWA section 1422 and the applicable implementing regulations in 40 CFR parts 144, 145, and 146.","action":"Proposed rule; notification of public hearing.","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/2026/03/19/2026-05453.html","cfr_references":[{"chapter":null,"citation_url":null,"part":147,"title":40}],"citation":"91 FR 13266","comment_url":"http://www.regulations.gov/commenton/EPA-HQ-OW-2025-2829-0001","comments_close_on":"2026-05-04","correction_of":null,"corrections":[],"dates":"Comments must be received on or before May 4, 2026.","disposition_notes":null,"docket_ids":["EPA-HQ-OW-2025-2829","FRL 12995-01-OW"],"dockets":[{"supporting_documents":[{"title":"ECMC Primacy submission May 2025","document_id":"EPA-HQ-OW-2025-2829-0014"},{"title":"ECMC Class VI Consultation letter to Uintah Ouray","document_id":"EPA-HQ-OW-2025-2829-0013"},{"title":"ECMC Class VI Consultation letter to Southern Ute Indian Tribe","document_id":"EPA-HQ-OW-2025-2829-0012"},{"title":"ECMC Class VI Consultation letter to Ute Mountain Ute Tribe","document_id":"EPA-HQ-OW-2025-2829-0011"},{"title":"ECMC Class VI Consultation letter to Navajo","document_id":"EPA-HQ-OW-2025-2829-0010"},{"title":"Colorado Class VI Applied Statutes and Regulations","document_id":"EPA-HQ-OW-2025-2829-0009"},{"title":"Colorado Primacy submission complete letter","document_id":"EPA-HQ-OW-2025-2829-0008"},{"title":"Colorado Public Participation Process","document_id":"EPA-HQ-OW-2025-2829-0007"},{"title":"Colorado Governor's Letter","document_id":"EPA-HQ-OW-2025-2829-0006"},{"title":"Colorado Class VI UIC Primacy Application","document_id":"EPA-HQ-OW-2025-2829-0005"}],"agency_name":"EPA","documents":[{"comment_count":1,"comment_start_date":"2026-03-19","updated_at":"2026-04-03T01:56:15.856-04:00","comment_url":"https://www.regulations.gov/commenton/EPA-HQ-OW-2025-2829-0001","allow_late_comments":false,"id":"EPA-HQ-OW-2025-2829-0001","comment_end_date":"2026-05-05","regulations_dot_gov_open_for_comment":true}],"supporting_documents_count":13,"id":"EPA-HQ-OW-2025-2829","title":"Colorado Underground Injection Control (UIC) Program; Class VI Primacy Application"}],"document_number":"2026-05453","effective_on":null,"end_page":13271,"executive_order_notes":null,"executive_order_number":null,"explanation":null,"full_text_xml_url":"https://www.federalregister.gov/documents/full_text/xml/2026/03/19/2026-05453.xml","html_url":"https://www.federalregister.gov/documents/2026/03/19/2026-05453/colorado-underground-injection-control-program-class-vi-primacy","images":{},"images_metadata":{},"json_url":"https://www.federalregister.gov/api/v1/documents/2026-05453?publication_date=2026-03-19","mods_url":"https://www.govinfo.gov/metadata/granule/FR-2026-03-19/2026-05453/mods.xml","not_received_for_publication":null,"page_length":6,"page_views":{"count":408,"last_updated":"2026-04-05 00:15:04 -0400"},"pdf_url":"https://www.govinfo.gov/content/pkg/FR-2026-03-19/pdf/2026-05453.pdf","presidential_document_number":null,"proclamation_number":null,"public_inspection_pdf_url":"https://public-inspection.federalregister.gov/2026-05453.pdf?1773837923","publication_date":"2026-03-19","raw_text_url":"https://www.federalregister.gov/documents/full_text/text/2026/03/19/2026-05453.txt","regulation_id_number_info":{},"regulation_id_numbers":[],"regulations_dot_gov_info":{"supporting_documents":[{"title":"ECMC Primacy submission May 2025","document_id":"EPA-HQ-OW-2025-2829-0014"},{"title":"ECMC Class VI Consultation letter to Uintah Ouray","document_id":"EPA-HQ-OW-2025-2829-0013"},{"title":"ECMC Class VI Consultation letter to Southern Ute Indian Tribe","document_id":"EPA-HQ-OW-2025-2829-0012"},{"title":"ECMC Class VI Consultation letter to Ute Mountain Ute Tribe","document_id":"EPA-HQ-OW-2025-2829-0011"},{"title":"ECMC Class VI Consultation letter to Navajo","document_id":"EPA-HQ-OW-2025-2829-0010"},{"title":"Colorado Class VI Applied Statutes and Regulations","document_id":"EPA-HQ-OW-2025-2829-0009"},{"title":"Colorado Primacy submission complete letter","document_id":"EPA-HQ-OW-2025-2829-0008"},{"title":"Colorado Public Participation Process","document_id":"EPA-HQ-OW-2025-2829-0007"},{"title":"Colorado Governor's Letter","document_id":"EPA-HQ-OW-2025-2829-0006"},{"title":"Colorado Class VI UIC Primacy Application","document_id":"EPA-HQ-OW-2025-2829-0005"}],"comments_count":1,"agency_id":"EPA","comments_url":"https://www.regulations.gov/docketBrowser?rpp=50&so=DESC&sb=postedDate&po=0&dct=PS&D=EPA-HQ-OW-2025-2829","supporting_documents_count":13,"docket_id":"EPA-HQ-OW-2025-2829","document_id":"EPA-HQ-OW-2025-2829-0001","regulation_id_number":null,"title":"Colorado Underground Injection Control (UIC) Program; Class VI Primacy Application","checked_regulationsdotgov_at":"2026-04-04T08:55:04Z"},"regulations_dot_gov_url":"http://www.regulations.gov/commenton/EPA-HQ-OW-2025-2829-0001","significant":null,"signing_date":null,"start_page":13266,"subtype":null,"title":"Colorado Underground Injection Control Program; Class VI Primacy","toc_doc":"Colorado; Class VI Primacy","toc_subject":"Underground Injection Control Program","topics":["Environmental protection","Incorporation by reference","Indians-lands","Intergovernmental relations","Reporting and recordkeeping requirements","Water supply"],"type":"Proposed Rule","volume":91}