UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON , D.C. 20460 APR 2 3 2015 OFFICE OF WA IER MEMORANDUM FROM: Peter C. Grevatt, Director Office of Ground Water and Drinking Water TO: Regional Water Division Directors SUBJECT: Key Principles in EPA's Undergrotmd Injection Control Program Class VI Rule Related to Transition of Class II Enhanced Oil or Gas Recove ry Wells to Class VI Most states have primary enforcement responsibility (i.e., primacy) for the Class II Underground Inj ection Control program fo r oil or gas-related injection activities, while EPA Regions currentl y retain direct implementation authority for the Class VI program in every stale. The shared implementation of the UIC program necessitates a clear articulation and common understanding of the potential for transition of enhanced recovery wells from Class II to Class VI, consistent with EPA's Class VI Rule. This memo is intended to emphasize the key principles in EPA ' s UIC Class VI Rule re lated to the transi tion from Class II to Class VI for ER wells that inject carbon dioxide for long-term storage. As Regions work with states on implementation of the Class VI program, I encourage you to assist states in submitting primacy applications for all well classes, including Class VI. EPA recognizes the importance of geologic sequestration of anthropogenic C02 for climate change mitigation. The UIC Class VI Rule was developed to facilitate GS and ensure protection of underground sources of drinking water from the pa11icular risks that large scale C02 injection for purposes of long­ tenn storage may pose. The fo llowing are key principles related to the transition of ER wells that store C02 from Class 11 operations to the Class Vl program: 1. Geologic storage of C02 can continue to be permitted under the UIC C lass II program. ER wells across tbe U. S. are currently permitted as UIC Class II wells. C02 storage associated with Class II well s is a common occurrence, and C02 can be safely stored where injected through Class II-permitted wells for the purpose of oil or gas-related recovery. 2. Use of anthropogenic C0 2 in ER operations does not necessitate a Class VI permit. ER operations can continue to be permitted as Class II wells, regardless of the source of C0 2. An owner or operator of an ER operation can switch from using a natural source to an anthropogenic source of C0 2 without triggering the need fo r a Class V I permit. lnterne1 Address (URU · http //wwwepa gov Recycled/ Recyclable · Printed w11h Vegetable 011 Based Inks on 100% Posiconsumer Process Chlonne Free Recycled Paper 3. Class VI site closure requirements are not required for Class II C02 injection operations. A Class II well that has been used for injection of anthropogenic or non-anthropogenic C02 and has been operated within its permit conditions can be closed as a Class lI well. 4. ƒ ER operations that are focused on oil or gas production will be managed under the Class II program. If oil or gas recovery is no longer a significant aspect of a Class n permitted ER operation, the key factor in determining the potential need to transition a C02 ER operation from Class II to Class VI is the increased risk to USDWs related to significant storage of C02 in the reservoir, where tbe regulatory tools of the Class II program cannot successfully manage the risk. The most direct indicator of increased risk to USDWs is increased pressure in the injection zone related to the significant storage of C02. Increases in pressure with the potential to impact USDWs should first be addressed using tools within the Class II program. Transition to Class VI should only be considered if the Class II tools are insufficient to manage the increased risk. 1 S. The Class II and Class VI directors should work together to address the potential need for transition of any individual operation from a Class II to a Class VI permit. The Class II program director (in most cases a state official) will have the relevant data on pressure and volume of C02 injected into Class II ER operations, which will influence any transition decision. EPA encourages the Class II director to contact the Class VI director where he/she believes the risk has changed as a result of significant storage of C02 in the reservoir. 6. ' The best implementation approach is for states to administer both the Class II and the Class VI UIC programs. EPA encourages states to apply for primacy for all well classes, including Class VI. Based on our conversations with states, in most cases, states who are approved for primacy for the Class VI program are expected to administer the program through their oil and gas program. The Office of Ground Water and Drinking Water is currently working with the U.S. Department of Energy, state associations, EPA Regions and stakeholders to finalize technical guidance focused on risk factors discussed in the Class VI Rule at 40 CFR 144.19. As we complete the final guidance, we will work to ensure that these key principles remain clear. Please contact me or have your staff contact Ron Bergman at 202-564 -3823 if we can be of assistance to you on these or other UIC program issues. 1 The key regulation, "Transitioning rrom Class 11 to Class VI," codified at 40 CFR 144.19, states that owners or operators that are injecting carbon diox idc for tile primary purpose of /oug-term storage into an oi I and gas reservoir must apply for and obtain a Class VI GS permit 111/ieu tllere is au increased risk to USDWs compared to Class II operations.