EPA has issued a final rule that establishes requirements for underground injection of carbon dioxide (CO2) to ensure safety and prevent the CO2 from causing groundwater contamination. The rule was issued under the authority of the Safe Drinking Water Act. It will require site characterization to ensure injection wells are located in areas that can store CO2 safely. Under the rule, wells must be constructed of materials compatible with injected material and include automatic shutoff systems to prevent unintended fluid movement. Well and storage site operators will be required to implement and update plans for management of the underground storage sites.

According to the agency, the rule includes rigorous testing and monitoring requirements, including testing the mechanical integrity of the wells, groundwater monitoring and tracking of the underground CO2 to verify that it is moving as predicted. The rule also clarifies and expands financial responsibility requirements to ensure that operators have funds for closure, emergency and remedial action, the correction of problems, and post-injection site care. The rule is effective 30 days after it is published in the Federal Register.