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Underground Injection Control (UIC)

Final Rulemaking for the Navajo Nation Class II Underground Injection Control Program

The Environmental Protection Agency (EPA) has approved an application from the Navajo Nation under Section 1425 of the Safe Drinking Water Act (SDWA) to grant the tribe primary enforcement responsibility (or "primacy") for the underground injection control (UIC) program for Class II (oil and gas-related) injection wells. The tribe’s application requested primacy for Class II wells located: within the exterior boundaries of the formal Navajo Reservation, including the three satellite reservations (Alamo, Canoncito and Ramah), but excluding the former Bennett Freeze Area, the Four Corners Power Plant and the Navajo Generating Station; and on Navajo Nation tribal trust lands and trust allotments outside the exterior boundaries of the formal Navajo Reservation.

EPA's final rulemaking decision is based on a careful and extensive legal and technical review of the Navajo Nation's primacy application, two public comments received, and other relevant information. As a result of the action, the Navajo Nation will administer and enforce its own program for the existing Class II injection wells and any future wells located within the areas described above. EPA will continue to administer its SDWA UIC program for any Class I, III, IV, and V wells on Navajo Indian lands.

Related Documents

Below are links to Federal Register notices, a press release and fact sheet that provide more information about this action. The public can access all publicly available documents in the docket (EPA-R09-OW-2007-0248) at

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