Summary
Details
- The United States of America (USA)
Mandatory for CO₂ injection for geologic sequestration. Not all CCS projects require Class VI (e.g., CO₂ injection for enhanced oil recovery uses Class II), but projects claiming long-term sequestration and relying on carbon credits or 45Q typically treat Class VI compliance as central to MRV credibility and legal durability.
Deep dive
📩 Stay ahead of climate regulation and reporting shifts
Regulatory updates, reporting standards, and new climate software — distilled into one concise weekly brief for decision-makers.
Thanks for signing up. Please check your inbox to confirm your subscription.
Practical updates. Once per week.
What’s Required
Class VI is a high-stringency permitting framework under the Safe Drinking Water Act (SDWA) administered by EPA or primacy states. Compliance obligations are embedded in permits and include multi-phase requirements from pre-permit characterization through post-injection site care.
1) Permit requirement and scope
A Class VI permit is required to inject CO₂ for long-term geologic sequestration. EPA describes Class VI wells as used to inject CO₂ into deep rock formations for long-term underground storage.
Operating without a permit, or outside permit conditions, is unlawful.
2) Site characterization and Area of Review (AoR) analysis
Permit applicants must conduct extensive geologic, hydrologic, and seismic characterization to demonstrate confining zone integrity and protection of underground sources of drinking water. AoR modeling identifies where injected CO₂ and pressure fronts may migrate and requires corrective action where legacy wells or pathways could compromise containment.
3) Monitoring, reporting, and verification (MRV) obligations
Permits require continuous or periodic monitoring of injection pressure, CO₂ plume movement, groundwater quality indicators, and well integrity parameters. Monitoring plans must be implemented and updated when conditions change. Recordkeeping and reporting are enforceable permit conditions.
4) Financial responsibility and long-term care
Operators must demonstrate financial responsibility for corrective action, injection well plugging, post-injection site care, and emergency/remedial response. This can include bonding, trust funds, or other mechanisms and is often a gating item for financing.
5) State primacy and permitting authority allocation
EPA can approve state primacy for Class VI, shifting permitting authority from EPA to the state (with EPA oversight). EPA proposed approving Texas’s Class VI primacy application in June 2025, illustrating how primacy decisions reshape project strategies, timelines, and stakeholder engagement.
Primacy does not reduce compliance stringency; it changes the regulator and procedural pathway.
Important Deadlines
Class VI is an ongoing permitting program with permit-specific milestones.
Primacy decisions follow Federal Register notice-and-comment timelines; Texas primacy proposal published June 17, 2025.
Current Status
Class VI requirements are in force nationally. Primacy expansions are actively pursued by states, potentially accelerating permitting in some jurisdictions while introducing new procedural expectations and regulator-specific guidance.
Penalties for Non-Compliance
SDWA enforcement: civil penalties, compliance orders, permit revocation.
Injunctive relief, including the shutdown of injection operations.
Liability for endangerment of underground sources of drinking water.
Contractual and tax-credit monetization impacts (e.g., inability to substantiate storage for credit claims).
Examples of Known Violations
Injection outside permitted pressure/volume limits.
Inadequate monitoring implementation or data gaps.
Failure to conduct corrective action for identified pathways.
Poor documentation and inability to demonstrate plume containment.
Financial responsibility lapses (expired bonds, insufficient coverage).
Resources
Cut through the green tape
We don't push agendas. At Net Zero Compare, we cut through the hype and fear to deliver the straightforward facts you need for making informed decisions on green products and services. Whether motivated by compliance, customer demands, or a real passion for the environment, you’re welcome here. We provide reliable information. Why you seek it is not our concern.