Public Notice: Proposed Rulemaking - Colorado Underground Injection Control Class VI Primacy

On October 7, 2025, Colorado submitted an application for primary enforcement responsibility (primacy) from the Underground Injection Control program under the Safe Drinking Water Act section 1422. Colorado is seeking to administer the UIC program for Class VI injection wells located within the State.  

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. The geologic sequestration of carbon dioxide in UIC Class VI wells is used as part of carbon capture and storage for carbon dioxide emissions from industrial sources. 

The EPA’s approval would allow the Colorado Energy and Carbon Management Commission to authorize underground injection for Class VI wells in the State in accordance with Underground Injection Control (UIC) program requirements. 

Public Comments  

EPA requests that written comments be sent on or before May 4, 2026, via the Federal Register for Docket ID No. EPA-HQ-OW-2025-2829 at https://www.regulations.gov. 

Public Hearing (Zoom for Government) 

Thursday, April 23, 2026  

5 to 8 pm Mountain Standard Time 

Register here: https://www.zoomgov.com/webinar/register/WN_tE6QV23SSHyy6MMGFTpZiQ#/registration

Each commenter will have three minutes to provide oral testimony.  

The EPA recommends submitting the text of your oral comments as written comments to the rulemaking docket identified by Docket ID No. EPA-HQ-OW-2025-2829 at https://www.regulations.gov. Alternatively, you can submit your oral testimony to UICprimacy@epa.gov.  

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.  

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 hearing to run either ahead of schedule or behind schedule. 

If you require the services of an interpreter or special accommodations such as audio description, please pre-register and describe your needs by April 16, 2026. The EPA may not be able to arrange accommodations without advance notice.   

Contact 

If you have any questions about any information on this webpage, please email UICprimacy@epa.gov. 

Learn More: Protecting Underground Sources of Drinking Water from Underground Injection, Underground Injection Control in Region 8, ECMC Class VI Program.