EPA Poised to Grant CCS Primacy to Colorado

On March 19, 2026, the U.S. Environmental Protection Agency (“EPA”) published a proposed rule to grant Colorado the authority to directly issue Class VI permits under the Safe Drinking Water Act’s Underground Injection Control (“UIC”) program for carbon capture and sequestration (“CCS”) wells. The proposal continues the Trump administration’s track record of expedited primacy approvals, aimed at clearing the backlog of Class VI permit applications pending at EPA. EPA will accept public comments on the proposal through May 4, 2026.

Primacy at Lightning Speed

The EPA’s proposal puts Colorado one step closer to obtaining primary enforcement authority, or primacy, over Class VI UIC wells in the state. Once EPA approves a final rule granting primacy, applicants will only need to secure approval from Colorado’s Energy and Carbon Management Commission (“ECMC”). Colorado would be the fourth state to gain primacy since President Trump took office, illustrating the administration’s commitment to cooperative federalism and to streamlining permitting processes for energy projects. Consistent with this approach, the EPA proposed to grant Colorado primacy just five months after it submitted its application in October 2025. The EPA approved Texas’s application in November 2025, Arizona’s in September 2025, and West Virginia’s in February 2025.

CCS in Colorado

Primacy often allows companies to speed up project development, as state timelines for approving Class VI UIC permits can be faster than EPA’s multi-year process. Colorado’s UIC program is somewhat nascent. Despite being one of the first states poised to obtain primacy, unlike many other states, Colorado currently only has primacy over Class II UIC wells used for disposal of oil and gas production wastes, enhanced recovery, or hydrocarbon storage. Only two applications for Class VI wells in Colorado are currently pending.

The EPA’s proposal to grant primacy also comes with federal sign-off of Colorado’s own Class VI regulations. However, Colorado’s regulations, which went into effect in November 2025, require consideration of factors that have become less prominent in federal reviews in recent months, such as cumulative environmental impacts and environmental justice concerns. Applicants must include an assessment of cumulative impacts from their proposed activities, as well as an analysis of effects on “disproportionately impacted communities,” defined to include census block groups with certain percentages of minority populations, low-income households, non-English speaking households, or certain other vulnerable populations.¹ The ECMC must deny applications sited within half a mile of certain facilities in such communities that would result in negative net cumulative impacts. Developers seeking to permit Class VI wells in Colorado should ensure that their permit application materials include a sufficiently rigorous analysis of cumulative and other environmental impacts to withstand potential regulatory and legal scrutiny. It remains to be seen the extent to which these provisions in Colorado’s regulations will be addressed during the public comment period or may affect the ultimate timeline for a final rule granting primacy.

Next Steps

The EPA will hold one public hearing on the proposal and will accept public comment through May 4, 2026. There remains potential for certain parties to try and disrupt the speedy promulgation of a final rule. Some environmental groups challenged EPA’s approval of primacy for Louisiana and West Virginia, though the Fifth Circuit has since dismissed the legal challenge to Louisiana’s primacy approval on the grounds that the plaintiffs’ alleged injuries were too speculative to support standing to sue. Nonetheless, it remains to be seen whether or not any such groups will continue to pursue challenges to primacy approvals.

We will continue to track developments related to CCS permitting. Please reach out to your V&E team to discuss these matters and their implications for your business.

¹2 Colo. Code Regs. § 404-1:100; Colo. Rev. Stat. Ann. § 24-4-109(2)(b)(II).

This information is provided by Vinson & Elkins LLP for educational and informational purposes only and is not intended, nor should it be construed, as legal advice.