On December 30, 2024, the U.S. Environmental Protection Agency (EPA) issued four Underground Injection Control (UIC) Class VI well permits to a subsidiary of California Resources Corporation (CRC).

The permits authorise CRC’s carbon management division Carbon TerraVault (CTV) to construct four deep injection wells at CRC‘s Elk Hills cryogenic gas plant in Kern County, California.

The wells will be constructed to depths of more than a mile below surface level, into the Monterey Formation. and will receive about 1.5 million metric tons of carbon dioxide annually from CRC’s pre-combustion gas treatment facility and other EPA-approved sources. The aim is to remove and store almost 38 million metric tons of CO₂ over a 26-year period.

EPA’s permits require extensive monitoring for well integrity and 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.

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 safely receive and store 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.