Class VI permit applicants must submit a PISC and Site Closure Plan that outlines the proposed post-injection monitoring strategies and how non-endangerment of USDWs will be ensured throughout the PISC phase [40 CFR 146.82(a)(17); 146.93]. The applicant may also submit a demonstration of an alternative post-injection site care timeframe per 40 CFR 146.82(a)(18). 

The purpose of the UIC Program’s review of the PISC and Site Closure Plan is to ensure that planned post-injection phase activities are appropriate to the project and address known uncertainties or data gaps. If the applicant submitted a demonstration of an alternative PISC timeframe, the UIC Program should evaluate the demonstration to ensure that it is suitable to the site-specific conditions, of an appropriate duration, and informed by modeling predictions. 

The UIC Program can also use the review as an opportunity to ensure, in coordination with the owner or operator, that the PISC and Site Closure Plan includes appropriate monitoring to validate modeled predictions, inform AoR reevaluations during the post-injection phase, and demonstrate non-endangerment. For additional information on evaluating the PISC and Site Closure Plan, see the UIC Program Class VI Well Project Plan Development Guidance

Source: Environmental Protection Agency. (2018, January). Geologic Sequestration of Carbon Dioxide Underground Injection Control (UIC) Program Class VI Implementation Manual for UIC Program Directors.  Page 99. Retrieved from