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Oil Field 13

Class VI Primacy

Colorado Class VI UIC History
In 2023, Senate Bills 23-285 and 23-016 expanded the regulatory authority of the Energy and Carbon Management Commission (ECMC) to include Class VI Underground Injection Control (UIC) wells. These wells are used exclusively for geologic carbon sequestration. The new laws enabled ECMC to pursue regulatory primacy for Class VI wells from the U.S. Environmental Protection Agency (EPA). They also established comprehensive permitting, siting, and community engagement requirements, including financial assurance, cumulative impact analysis, surface owner consent, and protections for Disproportionately Impacted (DI) Communities.

In 2024, House Bill 24-1346 further expanded ECMC’s jurisdiction by clarifying its authority over geologic storage operations and confirming that geologic storage resources (the underground pore space used for carbon sequestration) are owned by surface owners. The law also established a mechanism for forming geologic storage units. Building on these legislative foundations, ECMC has taken significant steps toward implementing a safe and effective Class VI program. Through 2024, ECMC was focused on building its Class VI regulations through thorough stakeholding efforts and community engagement. These and other efforts culminated in the adoption of Colorado’s Class VI UIC rules on December 16, 2024. The new rules meet or exceed federal standards and reflect Colorado’s values of public health, safety, welfare, environmental stewardship, and wildlife protection.

ECMC submitted Colorado’s Class VI primacy application to the EPA in the spring of 2025 and expects a final decision in early 2026. Once approved, Colorado will have the authority to permit and regulate Class VI wells directly. These developments position Colorado as a national leader in carbon storage regulation. They also ensure projects are carried out in a manner that protects Colorado’s people, land, water, and wildlife.

Colorado Class VI Rulemaking Documents
Pending Class VI Rules, Statement of Basis and Purpose, and all related rulemaking documents can be found on the Rulemaking page.

Note: The new rules and amendments become effective at such time that the United States Environmental Protection Agency (“EPA”) approves the Commission’s application for primacy over Class VI UIC Wells pursuant to the Safe Drinking Water Act, 42 U.S.C. 300h-1. Until that time, the Commission lacks the requisite authority to implement these new and revised rules, and Class VI UIC Wells in the state of Colorado will continue to be permitted and regulated by EPA. Upon obtaining primacy, the Commission’s Class VI rules will apply prospectively to new operations and existing Class VI permits in Colorado previously issued by EPA, unless otherwise specified in the text of a Rule.

Class VI Primacy Documents