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Water: Underground Injection Control

UIC Programs on Tribal Lands - UIC

This page provides information about injection activities on tribal lands and about tribes' eligibility for obtaining UIC Program primacy.

How many injection wells are on tribal lands?

The 2005 inventory of injection wells on tribal lands shows:

  • 1 Class I well,
  • 3,522 Class II wells, and
  • 1,739 Class V wells

There are no Class III or Class IV wells on tribal lands. The inventory information for Class I and Class II wells is complete. For Class V wells, the inventory is likely to increase as injection wells are located through outreach and inspection efforts.

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Can tribes apply for primacy?

Yes. The 1986 Amendments to the Safe Drinking Water Act (SDWA) added provisions that allow federally recognized tribes to assume primacy for UIC programs. Section 1451 of SDWA (“Indian Tribes”) authorizes EPA to treat Native American tribes in a manner similar to states and to assign primary enforcement responsibility (primacy) to qualified tribes.

Native American tribes follow the same rules for obtaining primacy as a state if they are considered a "Federally Recognized Tribe" and have been designated for "Treatment Similar to a State."

Tribes that want to enforce the federal UIC requirements must submit a primacy application to EPA. If the application meets the minimum federal requirements for a delegated program, EPA will delegate authority to implement the UIC program to the tribe.

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Are tribes currently seeking primacy?

Yes.  In October 2008, EPA approved applications from two tribes, under Section 1425 of the Safe Drinking Water Act (SDWA), to implement underground injection control (UIC) programs for Class II (oil and gas-related) injection wells.  The Fort Peck Assiniboine and Sioux Tribes in Montana and the Navajo Nation in Arizona, Utah, and New Mexico are the first tribes to receive UIC Class II primacy. 

Tribes that do not obtain UIC program delegation continue to be directly implemented by the EPA Regions. All EPA Regions (except Region 3, which has no federally recognized tribes), operate tribal UIC programs to manage injection wells on Native American lands.

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