Proposed Rule

Colorado Underground Injection Control Program; Class VI Primacy

A Proposed Rule by the Environmental Protection Agency on 03/19/2026

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• Public Inspection Published Document: 2026-05453 (91 FR 13266) Document Headings ###### Environmental Protection Agency

1. 40 CFR Part 147
2. [EPA-HQ-OW-2025-2829; FRL 12995-01-OW]

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule; notification of public hearing.

SUMMARY:

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.

DATES:

Comments must be received on or before May 4, 2026.

Public hearing: The EPA will hold one virtual public hearing during the comment period. Please refer to the SUPPLEMENTARY INFORMATION section for additional information on the public hearing.

ADDRESSES:

You may send comments, identified by Docket ID No. EPA-HQ-OW-2025-2829, by any of the following methods:

• Federal eRulemaking Portal: https://www.regulations.gov/ (our preferred method). Follow the online instructions for submitting comments.
• Mail: U.S. Environmental Protection Agency, EPA Docket Center, Water Docket, Mail Code 28221T, 1200 Pennsylvania Avenue NW, Washington, DC 20460.
• Hand Delivery or Courier: EPA Docket Center, WJC West Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004. The Docket Center's hours of operations are 8:30 ( printed page 13267) a.m. to 4:30 p.m., Monday through Friday (except Federal Holidays). Instructions: All submissions received must include the Docket ID No. for this rulemaking. Comments received may be posted without change to https://www.regulations.gov/, including personal information provided. For detailed instructions on sending comments and additional information on the rulemaking process, see the “Public Participation” heading of the SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT:

Mary Hastings Puckett, Drinking Water Infrastructure Development Division, Office of Ground Water and Drinking Water (4606M), Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington, DC 20460; telephone number: (202) 564-1525; or VelRey Lozano, UIC Program (8WD-SDU) U.S. Environmental Protection Agency, 1595 Wynkoop Street, Denver, Colorado 80202-8917; telephone number: (303) 312-6128. Both can be reached by emailing UICprimacy@epa.gov.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Public Participation

A. Written Comments

B. Participation in Public Hearing

II. Introduction

A. UIC Program and Primary Enforcement Authority (Primacy)

B. Class VI Wells Under the UIC Program

C. Colorado UIC Program

III. Legal Authorities

IV. Colorado's Application for UIC Class VI Primacy

A. Background

B. Public Participation Activities Conducted by Colorado

a. UIC Program Development Stakeholder Engagement

b. State Rulemaking

c. Proposal To Request UIC Program Primacy

C. Summary of the EPA's Comprehensive Evaluation

V. The EPA's Proposed Action

A. Incorporation by Reference

B. The EPA's Oversight

VI. Statutory and Executive Orders Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 14094: Modernizing Regulatory Review

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

C. Paperwork Reduction Act (PRA)

D. Regulatory Flexibility Act (RFA)

E. Unfunded Mandates Reform Act (UMRA)

F. Executive Order 13132: Federalism

G. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments

H. Executive Order 13045: Protection of Children From Environmental Health and Safety Risks

I. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use

J. National Technology Transfer and Advancement Act (NTTAA)

VII. References

I. Public Participation

A. Written Comments

Submit your comments, identified by Docket ID No. EPA-HQ-OW-2025-2829, at https://www.regulations.gov (our preferred method), or the other methods identified in the ADDRESSES section. Once submitted, comments cannot be edited or removed from the docket. The EPA may publish any comment received to its public docket. Do not submit to the EPA's docket at https://www.regulations.gov any information you consider to be Confidential Business Information (CBI), Proprietary Business Information (PBI), or other information whose disclosure is restricted by statute. If you wish to submit CBI, contact VelRey Lozano using the contact information available in the FOR FURTHER INFORMATION CONTACT section. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission (i.e., on the web, cloud, or other file sharing system). Please visit https://www.epa.gov/​dockets/​commenting-epa-dockets for additional submission methods; the full EPA public comment policy; information about CBI, PBI, or multimedia submissions; and general guidance on making effective comments.

B. Participation in Public Hearing

The EPA will hold one virtual public hearing during the public comment period. To register to speak at the virtual hearing, please use the online registration form available at https://epa.gov/​uic/​co-primacy or contact us by email at UICprimacy@epa.gov. One week prior to the public hearing, the EPA will post a general agenda for the hearing that will list pre-registered speakers in approximate order at: https://epa.gov/​uic/​co-primacy. Please refer to https://epa.gov/​uic/​co-primacy for additional updates, including the date and time, related to this public hearing.

The EPA will make every effort to follow the schedule as closely as possible on the day of the hearing; however, please plan for the hearings to run either ahead of schedule or behind schedule. Each commenter will have three minutes to provide oral testimony. The EPA encourages commenters to provide the EPA with a copy of their oral testimony electronically by emailing it to UICprimacy@epa.gov. The EPA also recommends submitting the text of your oral comments as written comments to the rulemaking docket, identified in the ADDRESSES section of this proposed rule. The EPA will make every effort to accommodate all speakers who register, although preferences on speaking times may not be able to be fulfilled.

The EPA may ask clarifying questions during the oral presentations but will not respond to the presentations at that time. Written statements and supporting information submitted during the comment period will be considered with the same weight as oral comments and supporting information presented at the public hearing.

Updates on the virtual hearing logistics will be posted online at https://epa.gov/​uic/​co-primacy. Please contact VelRey Lozano using the contact information available in the FOR FURTHER INFORMATION CONTACT section or email UICprimacy@epa.gov with any questions about the virtual hearing. The EPA does not intend to publish a document in the Federal Register announcing updates related to the public hearing. If you require the services of an interpreter or special accommodations such as audio description, please pre-register for the hearing at https://epa.gov/​uic/​co-primacy and describe your needs at least one week prior to the public hearing date. The EPA may not be able to arrange accommodations without advance notice.

II. Introduction

A. UIC Program and Primary Enforcement Authority (Primacy)

The Safe Drinking Water Act (SDWA) protects public health by regulating the nation's public drinking water supply, including both surface and groundwater sources. SDWA requires the EPA to develop minimum requirements for effective State and Tribal UIC programs to prevent underground injection of fluids (such as water, wastewater, brines from oil and gas production, and carbon dioxide) from endangering underground sources of drinking water (USDWs). In general, USDWs are aquifers or parts of aquifers that supply a public water ( printed page 13268) system or contain enough groundwater to supply a public water system. See 40 CFR 144.3 (defining USDW).

The EPA's UIC program regulates various aspects of an injection well project, including technical aspects throughout the life of the project from site characterization, construction, operation, testing and monitoring, and site closure, as well as permitting, site inspections, and reporting to ensure well owners and operators comply with UIC permits and regulations.

SDWA section 1421 directs the EPA to establish requirements that States, territories, and federally recognized Tribes (hereafter referred to as applicants) must meet to be granted primacy for implementing a UIC program, including a Class VI program. 42 U.S.C. 300h. An applicant seeking primacy under SDWA section 1422 for a Class VI program must demonstrate to the EPA that the applicant's Class VI program meets the Federal requirements for protecting USDWs promulgated by the EPA pursuant to SDWA section 1421. 42 U.S.C. 300h-300h-1. An applicant must demonstrate, among other things, that it has jurisdiction over underground injection and that it possesses the administrative, civil, and criminal enforcement authorities required by the EPA's implementing regulations. See 40 CFR part 145, subpart B. After the EPA approves UIC primacy for a State, the State's UIC program may be revised with the EPA's approval. See 40 CFR 145.32.

The EPA comprehensively evaluates each primacy application in accordance with SDWA section 1422 to determine whether the State has satisfactorily demonstrated that it has adopted and will implement a UIC program that meets applicable regulatory requirements.

B. Class VI Wells Under the UIC Program

Class VI wells are used to inject carbon dioxide into deep rock formations for the purpose of long-term underground storage, also known as geologic sequestration. Class VI injection wells are regulated under a SDWA permitting framework that protects USDWs.

The UIC Class VI program provides multiple safeguards that work together to protect USDWs. Owners or operators that wish to inject carbon dioxide underground for the purpose of geologic sequestration must obtain a Class VI permit for each well while demonstrating that their proposed injection well and injection activities will meet all regulatory requirements throughout the life of the project. The UIC Class VI program requires applicants to meet technical, financial, and managerial requirements to obtain a Class VI permit, including:

• Site characterization to ensure the geology in the project area will contain the carbon dioxide within the zone where it is authorized to be injected.
• Modeling to delineate the predicted area influenced by injection activities through the lifetime of the project.
• Evaluation of the delineated area to ensure all potential pathways for fluid movement have been identified and addressed through corrective action.
• Well construction requirements that ensure the Class VI injection well will not leak carbon dioxide.
• Testing and monitoring throughout the life of the project, including after carbon dioxide injection has ended. Requirements include, for example, testing to ensure physical integrity of the well, monitoring for seismic activity near the injection site, monitoring of injection pressure and flow, chemical analysis of the carbon dioxide stream that is being injected, and monitoring the extent of the injected carbon dioxide plume and the surrounding area (e.g., ground water) to ensure the carbon dioxide is contained as predicted.
• Operating requirements (for example, injection pressure limitations) to ensure the injection activity will not endanger USDWs.
• Financial assurance mechanisms sufficient to cover the costs for all phases of the geologic sequestration project including the post-injection site care period and until site closure has been approved by the permitting authority.
• Emergency and remedial response plans to protect USDWs.
• Reporting of all testing and monitoring results to the permitting authority to ensure the well is operating in compliance with all permit requirements. The permitting authority ensures that these protective requirements are included in each Class VI permit. A draft of each Class VI permit is made available to the public for comment before the decision is made whether to issue a final permit.

C. Colorado UIC Program

The State of Colorado received primacy for Class II injection wells under SDWA section 1425 on April 2, 1984 (49 FR 13040). On October 7, 2025, Colorado applied to the EPA under SDWA section 1422 for primacy for Class VI injection wells located within the State, except those located on Indian lands for which the EPA retains primacy.

III. Legal Authorities

This regulation is proposed under the authority of SDWA sections 1422 and 1450, 42 U.S.C. 300h-1 and 300j-9.

SDWA section 1421 requires the EPA Administrator to promulgate Federal requirements for effective State UIC programs to prevent underground injection activities that endanger USDWs. 42 U.S.C. 300h. SDWA section 1422 requires States seeking primacy to demonstrate to the EPA that the State has adopted (after notice and public hearing) and will implement a UIC program which meets the requirements that EPA promulgated under section 1421.

For States and Tribes seeking EPA primacy approval for UIC programs under SDWA section 1422, the EPA has promulgated regulations setting forth the applicable procedures and substantive requirements. The regulations in 40 CFR part 144 outline general program requirements that each State must meet to obtain primacy. The regulations in 40 CFR part 145 specify the procedures the EPA follows when considering applications for primacy, applications for program revisions, and withdrawing State programs, and outlines the elements and provisions that a State must include in its application for primacy. The regulations in 40 CFR part 145 also include requirements for State UIC permitting procedures (by reference to certain provisions of 40 CFR parts 124 and 144), compliance evaluation programs, and enforcement authority, as well as requirements for sharing information between the EPA and the State. The regulations in 40 CFR part 146 contain the technical criteria and standards applicable to each well class, including Class VI wells.

IV. Colorado's Application for UIC Class VI Primacy

A. Background

On October 7, 2025, Colorado submitted to the EPA a complete application for primary enforcement responsibility for Class VI wells, except those on Indian lands, under the authority of SDWA section 1422. Colorado's UIC primacy application includes a description of the State's proposed UIC Class VI program, copies of all applicable rules and forms, an Attorney General's statement of legal authority, a summary of Colorado's public participation activities, and a Memorandum of Agreement (MOA) between Colorado and the EPA's Region 8 office. The EPA reviewed the application for completeness and ( printed page 13269) performed a technical evaluation of the application materials.

B. Public Participation Activities Conducted by Colorado

a. UIC Program Development Stakeholder Engagement

Before the EPA can approve a State's application for Class VI permitting and primary enforcement authority, or “primacy,” the State must have the proper statutory and regulatory authority to administer a UIC Class VI program in accordance with the SDWA and applicable regulations. 42 U.S.C. 300h-1(b)(1)(A)(i); 40 CFR part 145, subpart B. Thus, prior to submitting a Class VI primacy application for the EPA's approval, Colorado needed to expand ECMC's regulatory authority to include direct air capture facilities and geologic storage operations. ECMC conducted a comprehensive state rulemaking process that included extensive stakeholder outreach and engagement. The goal of the outreach efforts was to inform stakeholders about ECMC's rule development process and to explain and present drafts of the State rules. Transparency and engagement were central in the outreach process. ECMC hosted a series of hybrid, virtual, and in-person outreach engagements across the State, reaching the general public, the regulated community, and the Tribes located in Colorado. ECMC also presented on Class VI primacy at a public hearing, led a carbon management tour for communities near a potential development, and held seven general stakeholder meetings and several targeted stakeholder meetings. On July 1, 2023, state law SB23-016 became effective and expanded ECMC's authority to include regulation of direct air capture facilities and geologic storage operations in Colorado.

b. State Rulemaking

Once the State expanded ECMC's authority, ECMC held a series of virtual stakeholder engagements and rulemaking hearings from June to December 2024, to develop regulations for Class VI injection wells. The engagements provided opportunities for public input and informed the development of Colorado's Class VI rules. Following ten Class VI rulemaking and primacy hearings, ECMC finalized the rules for a UIC Class VI program on December 16, 2024.

c. Proposal To Request UIC Program Primacy

As part of a UIC Class VI primacy application, a State must satisfactorily show that it has adopted Class VI program requirements after reasonable notice and public hearings. 42 U.S.C. 300h-1(b)(1)(A)(i); 40 CFR 145.31(a), (b). In February 2025, ECMC published notices of public hearings in seven Colorado newspapers, on its website, and via email distribution to stakeholders. The public notice provided the hearing schedule and identified specific issues for which ECMC sought public input. ECMC received public input during the hearings on the State's intent to request UIC Class VI primacy from the EPA and whether ECMC has the resources to manage a UIC Class VI program in a safe and effective manner as required by SDWA section 1422 and the UIC regulations. During the 30-day comment period, ECMC received one oral comment. The commenter expressed general concerns regarding carbon capture and storage, referencing the Archer-Daniels-Midland (ADM) project, an existing Class VI project outside Colorado, and legislation regarding the 45Q tax credit. ECMC summarized and addressed the input in the responsiveness summary; the comment did not necessitate any changes to the State's proposed primacy application.

Documentation of Colorado's public participation activities, including comments received by the public and ECMC's responses, can be found in the EPA's Docket ID No. EPA-HQ-OW-2025-2829.

C. Summary of the EPA's Comprehensive Evaluation

The EPA evaluates primacy applications in accordance with SDWA section 1422 to determine whether an applicant has satisfactorily demonstrated that it has adopted and will implement, after reasonable notice and public hearings, a UIC program that meets the requirements of 40 CFR parts 144, 145, and 146. The EPA conducted a comprehensive technical and legal evaluation of Colorado's primacy application to determine whether the State's proposed UIC Class VI program—including statutes and regulations, program description, Attorney General statement, and MOA—meets the requirements of SDWA section 1422 and EPA regulations. Upon review, the EPA determined that Colorado's primacy application demonstrates that the State has adopted and will implement a UIC Class VI program that meets the requirements of 40 CFR parts 144, 145, and 146.

The EPA evaluated Colorado's UIC Class VI program description for consistency with 40 CFR 145.23, which specifies all the information that must be included as part of the program description. The EPA's evaluation of the UIC Class VI program description included reviewing the scope, coverage, processes, and organizational structure of the proposed Class VI program. The EPA evaluated Colorado's permitting, administrative, and judicial review procedures relevant to Class VI permits, as well as the State's permit application, reporting, and manifest forms for Class VI permits. The EPA also reviewed the State's UIC compliance evaluation program and enforcement authorities and the State's demonstration that its UIC Class VI program will have adequate in-house staff or access to contractor support for technical areas including site characterization, modeling, well construction and testing, financial responsibility, and regulatory and risk analysis.

The EPA evaluated Colorado's Class VI related Attorney General's statement for consistency with 40 CFR 145.24. In an Attorney General's statement, the State's top legal officer affirms that applicable State law (e.g., statutes, regulations, and judicial decisions) provides adequate authority to administer the UIC Class VI program as described in the program description and consistent with the EPA's regulatory requirements for UIC programs.

The EPA determined that the Class VI MOA meets the Federal requirements at 40 CFR 145.25 for primacy MOAs. The MOA is the central agreement that establishes the provisions and arrangements between the State and the EPA concerning the administration and enforcement of the State UIC Class VI program. The EPA's evaluation of the Class VI MOA included ensuring that the MOA contained the appropriate provisions pertaining to coordination, permitting, compliance monitoring, enforcement, and EPA oversight. For example, the Class VI MOA addendum specifies that the ECMC and the EPA agree to maintain a high level of cooperation and coordination to assure successful and effective administration of the UIC Class VI program.

Colorado has demonstrated that it meets all UIC permit requirements found in 40 CFR 145.11 for Class VI permits. Colorado's UIC Class VI permitting provisions and technical criteria and standards meet the Federal requirements in 40 CFR parts 124 and 144 through 146. The State has incorporated necessary procedures, pursuant to 40 CFR 145.12, to support a robust UIC Class VI compliance evaluation program. Additionally, Colorado has the necessary civil, administrative, and criminal enforcement authorities pursuant to 40 ( printed page 13270) CFR 145.13. Colorado's UIC Class VI regulations regarding permitting, inspection, operation, monitoring, reporting, and recordkeeping meet Federal requirements found in 40 CFR parts 145 and 146.

As a result of this comprehensive review, the EPA is proposing to approve Colorado's UIC program primacy application. The EPA has determined that the application meets all applicable requirements for Class VI primacy approval under SDWA section 1422 and the State has demonstrated that it is prepared to implement a UIC program in a manner consistent with the SDWA and all applicable UIC regulations.

V. The EPA's Proposed Action

A. Incorporation by Reference

The EPA is proposing to approve the State of Colorado's UIC program primacy application for Class VI injection wells in the State, except for those located on Indian lands for which the EPA retains primacy. If finalized, this action would amend 40 CFR 147.301 and incorporate by reference Colorado's EPA-approved statutes and implementing regulations that contains standards, requirements, and procedures applicable to UIC Class VI well owners or operators within the State. Any provisions incorporated by reference, as well as all permit conditions issued pursuant to such provisions, are enforceable by the EPA pursuant to SDWA section 1423 and 40 CFR 147.1(e).

The EPA compiled the applicable Colorado statutes and regulations proposed to be incorporated by reference into 40 CFR 147.301 in a document titled “Colorado SDWA § 1422 Underground Injection Control Program Class VI Statutes and Regulations,” dated December 4, 2025. This compilation is publicly available at https://www.regulations.gov in the EPA's Docket No. EPA-HQ-OW-2025-2829 for this proposed rulemaking. The EPA also proposes to codify a table in 40 CFR 147.301 listing the EPA-approved Colorado Statutes and Regulations for Class VI wells that the EPA would incorporate by reference.

B. EPA Oversight

Upon approval, the EPA would oversee Colorado's administration of its Class VI UIC program. The EPA will require quarterly reports on instances of permittee non-compliance and annual UIC performance reports pursuant to 40 CFR 144.8. The MOA between the EPA Region 8 and ECMC specifies that the EPA will oversee the State's administration of the UIC Class VI program on a continuing basis to assure that such administration is consistent with the program MOA, the SDWA and implementing regulations, UIC grant agreements, and other applicable requirements.

VI. Statutory and Executive Orders Reviews

Additional information about these statutes and Executive orders can be found at: https://www.epa.gov/​laws-regulations/​laws-and-executive-orders.

A. Executive Order 12866: Regulatory Planning and Review and Executive Order 14094: Modernizing Regulatory Review

This action is exempt from review under Executive Order 12866 because the Office of Management and Budget (OMB) has exempted, as a category, the approval of State UIC programs.

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

Executive Order 14192 does not apply because actions that approve State UIC programs are exempted from review under Executive Order 12866.

C. Paperwork Reduction Act (PRA)

This action will not impose an information collection burden under the PRA. OMB has previously approved the information collection activities contained in the existing regulations and has assigned OMB control number 2040-0042. Reporting or recordkeeping requirements will be based on Colorado's UIC Class VI Regulations, and the State of Colorado is not subject to the PRA.

D. Regulatory Flexibility Act (RFA)

I certify that this action will not have a significant economic impact on a substantial number of small entities under the RFA. This action will not impose any burdens on small entities as this action transfers regulatory authority from the EPA to a State program with substantially the same requirements.

E. Unfunded Mandates Reform Act (UMRA)

This action does not contain an unfunded mandate as described in UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect small governments. The action imposes no enforceable duty on any State, local, or Tribal governments or the private sector. The EPA's proposed approval of Colorado's Class VI program will not constitute a Federal mandate because there is no requirement that a state establish UIC regulatory programs and because the program is a State, rather than a Federal program.

F. Executive Order 13132: Federalism

This action does not have Federalism implications. It will not have substantial direct effects on the states, on the relationship between the National Government and the states, or on the distribution of power and responsibilities among the various levels of government.

G. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments

This action does not have Tribal implications as specified in Executive Order 13175. This action contains no Federal mandates for Tribal governments and does not impose any enforceable duties on Tribal governments. Thus, Executive Order 13175 does not apply to this proposed action.

H. Executive Order 13045: Protection of Children From Environmental Health and Safety Risks

The EPA interprets Executive Order 13045 as applying only to those regulatory actions that concern environmental health or safety risks that the EPA has reason to believe may disproportionately affect children, per the definition of “covered regulatory action” in section 2-202 of the Executive Order. This action is not subject to Executive Order 13045 because it approves a State program.

I. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use

This action is not subject to Executive Order 13211, because it is not a significant regulatory action under Executive Order 12866.

J. National Technology Transfer and Advancement Act (NTTAA)

This rulemaking does not involve technical standards.

VII. References

Attorney General's Statement “Attorney General's Statement to Accompany Colorado's Underground Injection Control Program Class VI Primacy Application”, signed by the Attorney General of Colorado on May 27, 2025.

Class VI Underground Injection Control Program Description “Colorado Class VI Underground Injection Control 1422 Program Description”, Colorado Energy and Carbon Management Commission, October 7, 2025.

Letter from the Governor of Colorado to the Regional Administrator, EPA Region 8, signed on April 2, 2025. ( printed page 13271)

The Memorandum of Agreement Between the Colorado Energy and Carbon Management Commission and The United States Environmental Protection Agency Region 8 for the UIC Class VI Program signed by the EPA Regional Administrator on October 8, 2025.

State of Colorado Energy and Carbon Management Commission of Colorado Department of Natural Resources UIC Class VI Primacy Application, “Relevant State Statutes and Regulations”, October 7, 2025.

State of Colorado Energy and Carbon Management Commission of the Colorado Department of Natural Resources UIC Class VI Primacy Application, “Public Participation Documentation”, October 7, 2025.

U.S. Environmental Protection Agency. Proposed “Colorado SDWA § 1422 Underground Injection Control Program Statutes and Regulations for Well Class VI to be Incorporated by Reference.” December 4, 2025. Office of Water.

List of Subjects in 40 CFR Part 147

• Environmental protection
• Incorporation by reference
• Indian lands
• Intergovernmental relations
• Reporting and recordkeeping requirements
• Water supply Lee Zeldin,

Administrator.

For the reasons set forth in the preamble, the EPA proposes to amend 40 CFR part 147 as follows:

PART 147—STATE, TRIBAL, AND EPA-ADMINISTERED UNDERGROUND INJECTION CONTROL PROGRAMS

1. The authority citation for part 147 continues to read as follows:

Authority: 42 U.S.C. 300f et seq.; and 42 U.S.C. 6901 et seq.

1. Redesignate § 147.301 through § 147.305 to § 147.302 through § 147.306

2. Add § 147.301 to read as follows:

§ 147.301 State-administered program—Class VI Wells The UIC program for Class VI wells in the State of Colorado, except for those wells on Indian lands, is the program administered by the Colorado Energy and Carbon Management Commission approved by EPA pursuant to section 1422 of the Safe Drinking Water Act (SDWA). The UIC Program for Class VI wells in the State of Colorado, except those located on Indian lands, is the program administered by the Colorado Energy and Carbon Management Commission, approved by the EPA pursuant to section 1422 of the SDWA. The effective date of this program is [DATE 30 DAYS AFTER DATE OF PUBLICATION OF THE FINAL RULE IN FEDERAL REGISTER ]. The UIC program for Class VI wells in the State of Colorado, except those located on Indian lands, consists of the following elements, as submitted to EPA in the State's program application.

(a) Incorporation by reference. The requirements set forth in the State statutes and regulations cited in this paragraph are hereby incorporated by reference and made part of the applicable UIC program under SDWA for the State of Colorado. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained at the State of Colorado Energy and Carbon Management Commission, 1120 Lincoln Street. Suite 801, Denver, Colorado 80203. Copies of the State of Colorado's provisions that are incorporated by reference may be inspected at the U.S. Environmental Protection Agency, Water Docket, EPA Docket Center (EPA/DC), EPA WJC West, Room 3334, 1301 Constitution Ave. NW, Washington, DC 20004, or Region 8, U.S. Environmental Protection Agency, 1595 Wynkoop Street, Denver, Colorado 80202-1129. If you wish to obtain this material from the EPA Docket Center, call (202) 566-2426. Copies of this material also may be inspected at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit www.archives.gov/​federal-register/​cfr/​ibr-locations or email fr.inspection@nara.gov.

• * * * * (1) Colorado SDWA Sec. 1422 Underground Injection Control Program Statutes and Regulations for Well Class VI to be Incorporated by Reference.

| State citation | Title/subject | State finalization date | EPA approval date |
| --- | --- | --- | --- |
| C.R.S. 24-4-101 through 24-4-109 | Colorado Administrative Procedure Act | December 16, 2024 | [DATE OF PUBLICATION OF THE FINAL RULE IN FEDERAL REGISTER ]. |
| C.R.S. 34-60-101 through 34-60-143 | Oil and Gas Conservation Act | December 16, 2024 | [DATE OF PUBLICATION OF THE FINAL RULE IN FEDERAL REGISTER ]. |
| 2 CCR 404-1, series 100, 200, 500, 600, 900, 1400 | Department of Natural Resources Energy and Carbon Management Commission Rules of Practice and Procedure | December 16, 2024 | [DATE OF PUBLICATION OF THE FINAL RULE IN FEDERAL REGISTER ]. |
(b) Memorandum of Agreement. The Memorandum of Agreement Between Colorado Energy and Carbon Management Commission and The United States Environmental Protection Agency Region VIII for the UIC Class VI Program, signed by the EPA Regional Administrator October 8, 2025.

(c) Governor's Letter. Letter from the Governor of Colorado to the Regional Administrator, EPA Region VIII, signed on April 2, 2025.

(d) Statement of Legal Authority. Attorney General's Statement to Accompany Colorado's Underground Injection Control Program Class VI Primacy Application”, signed by the Attorney General of Colorado on May 27, 2025.

(e) Program Description. The Program Description, “Colorado Class VI Underground Injection Control Program (1422) Description”.

[FR Doc. 2026-05453 Filed 3-18-26; 8:45 am]

BILLING CODE 6560-50-P

Published Document: 2026-05453 (91 FR 13266)