On 30 December 2024, the US Environmental Protection Agency (EPA) issued four Underground Injection Control (UIC) Class VI well permits to Carbon TerraVault JV Storage Company Sub 1, LLC (CTV), a subsidiary of California Resources Corporation (CRC).

Class VI UIC wells are used to inject carbon dioxide into deep rock formations for permanent underground storage. This technology, called carbon capture and underground storage or geologic sequestration, can be used to reduce carbon dioxide emissions to the atmosphere and mitigate climate change. The four Class VI UIC permits are for the first permitted Class VI injection wells in California and represent the first such permits issued by EPA’s Pacific Southwest Region.

EPA has determined that the activities authorized under the Class VI UIC permits are protective of underground sources of drinking water and public health as required by the Safe Drinking Water Act (SDWA). EPA completed a thorough technical review of all information submitted by CTV in its permit application, as well as the operational standards, the monitoring requirements, and the existing geologic setting.

In order to ensure the surrounding community could provide input, EPA held public comment periods and reviewed thousands of public comments submitted on the draft permits. EPA also met with local officials in Kern County, emergency responders, community members, and property owners to explain the Class VI well program, listen to concerns, and answer questions.

The permits authorize CTV to construct four deep injection wells in the Elk Hills Oil Field, approximately 20 miles west of Bakersfield, California. The wells will be constructed to depths of more than a mile below surface level, into the Monterey Formation. CTV plans to inject about 1.5 million metric tons of carbon dioxide per year for 26 years, totaling almost 38 million metric tons of carbon dioxide removed and stored.

CTV will capture the carbon dioxide from the generating facilities, transport it via pipeline within the Elk Hills field to the injection wells, pressurize the gas into a liquid-like state, and inject the carbon dioxide stream deep into the ground through the well. The permits identify CRC’s pre-combustion gas treatment within the Elk Hills Oil Field as the initial carbon dioxide source and prescribe a process for CTV to add additional sources of carbon dioxide with EPA’s approval.

EPA’s permits require extensive monitoring for well integrity, ground water quality and to track carbon dioxide movement. In addition, CTV must conduct surface-level air and leak detection monitoring to ensure that the injected carbon dioxide is staying underground. CTV will provide the surface air and leak detection monitoring data along with other monitoring data on a publicly accessible website. CTV is also required to plan for emergencies and maintain an Emergency and Remedial Response Plan, which includes an Emergency Communication Plan to inform the public of any unanticipated event that requires an emergency response.

Before EPA will authorize the start of carbon dioxide injection, CTV is required to properly plug 200 wells where carbon dioxide is expected to migrate during the project. EPA will review and approve the final plugging records to ensure that the wells do not allow carbon dioxide to migrate upward into underground sources of drinking water.

Based on EPA’s review of CTV’s application, including maps, well logs, cores, and the results of seismic surveys, EPA determined that the regional and local geologic features of the site will allow the Monterey Formation to receive and store safely the total volume of carbon dioxide authorized for injection. In addition, the confining zone—the geologic formation that overlies the injection formation—provides a suitable trap for the carbon dioxide to remain in place without migration.

EPA also reviewed historic seismicity data in the area, including an assessment of faults and fractures, as well as the probability of induced seismicity due to injection activities. Based on this review, EPA determined that the injection operations are unlikely to cause seismic activity or containment issues.

EPA will also require CTV to maintain financial responsibility throughout the life of the project to plug the injection wells, perform all required post-injection site care, properly decommission the site at the end of project operations, and conduct any needed emergency and remedial response measures. CTV has secured approximately $30,000,000 for these activities. EPA has reviewed and approved this amount and will continue to review the cost of the activities and require CTV to update the amount on an annual basis if there are changes.

While the Class VI UIC permits issued by EPA authorize the injection of carbon dioxide pursuant to the federal Safe Drinking Water Act (SDWA), the permits do not relieve CTV of complying with applicable federal, state or local laws or regulations.

The Class VI UIC permits are in effect during the operating life of the injection wells and the post-injection site care period until site closure is completed.