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Clean Water Act Tribal Provision

Overview Prepared by the U.S. Environmental Protection Agency

Office of Water and Office of General Counsel

May 2015

Summary

The majority of Indian reservations do not have water quality standards to protect human health 

and the environment. Only 40 of the more than 300 federally recognized tribes with reservations 

have completed the process of obtaining EPA’s approval to be treated in a manner similar to a 

state (TAS) and adopted standards for their waters that EPA has approved. 

EPA is considering a new approach to tribal authority to obtain TAS status for the water quality 

standards program and other Clean Water Act regulatory programs. The new approach would 

streamline the process for applicant tribes and advance cooperative federalism by facilitating 

tribal involvement in the protection of reservation water quality as intended by Congress.

Background

Since 1991, EPA has followed a cautious 

approach that requires applicant tribes to 

demonstrate their inherent authority to 

regulate waters and activities on their 

reservations under principles of federal 

Indian law. 

The Agency has consistently stated that its 

approach was subject to change in the event 

of further congressional or judicial guidance 

addressing tribal authority under Section 

518 of the Clean Water Act. 

Having received such guidance, EPA is 

considering whether to reinterpret Section 

518 as an express delegation of authority by 

Congress to eligible Indian tribes to 

administer regulatory programs over their 

entire reservations. 

What would the new approach do?

It would allow tribes applying for TAS to 

administer CWA regulatory programs to 

rely on a congressional delegation under 

Section 518 as the source of authority to 

regulate their reservation waters. Tribes 

would no longer need to demonstrate their 

inherent authority to regulate under the 

CWA. 

It would also bring EPA’s treatment of 

tribes under the Clean Water Act in line with 

EPA’s treatment of tribes under the Clean 

Air Act, which has similar statutory 

language addressing tribal regulation of 

resources in reservation areas. 

What would not change under the new 

approach?

This new approach would not revise any text 

in EPA regulations. 

All existing regulatory provisions would 

remain in effect, including those that 

provide for tribes to identify the boundaries 

of the reservation areas over which they 

seek to exercise authority and for adjacent 

state(s) to have an opportunity to comment 

to EPA on an applicant tribe’s assertion of 

authority.

Would the new approach affect the 

geographic scope of TAS?

No. The proposal would neither expand nor 

contract the geographic scope of potential 

tribal TAS eligibility. Under the Clean 

Water Act, tribes can only obtain TAS status 

over their reservations. 
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Would the new approach affect any 

existing limitations on tribal criminal 

enforcement authority?

No. The proposal relates solely to civil 

regulatory authority.

What if my tribe or state has special 

circumstances affecting CWA regulatory 

authority?

There could be instances where special 

circumstances would limit or preclude a 

particular tribe's ability to accept or 

effectuate the congressional delegation of 

authority over its reservation. For example, 

there could be a separate federal statute 

establishing unique jurisdictional 

arrangements for a specific state or 

reservation. Any such issue would be 

addressed on a case-by-case basis and with 

the benefit of a full record of relevant 

information that would be developed during 

the processing of a particular tribe's 

application for eligibility to regulate under 

the Clean Water Act. 

Who may be affected by or interested in 

this potential action?

 Federally recognized Indian tribes with 

reservations that could potentially seek 

eligibility to administer CWA regulatory 

programs, and other interested tribes.

 States adjacent to potential applicant 

tribes. 

 Industries or municipalities discharging 

pollutants to waters within or adjacent to 

reservations of potential applicant tribes.

Would the potential action affect previous 

EPA approvals of TAS for water quality 

standards?

No. It would not affect the 49 previous EPA 

approvals of tribal TAS for water quality 

standards.

Would the proposal affect the scope of 

existing state regulatory programs 

approved by EPA under the Clean Water 

Act?

No. The new approach would have no 

effect on the scope of existing state 

regulatory programs approved by EPA 

under the CWA. It would not diminish or 

enlarge the scope of such approved state 

programs.

How would EPA adopt the new 

approach?

EPA would publish a notice in the Federal 

Register proposing the action and provide an 

opportunity for public comment before 

making any final change. 

For more information

Contact Fred Leutner at 

Leutner.Fred@epa.gov or (202) 566-0378, 

or visit EPA's website at 

http://water.epa.gov/scitech/swguidance/stan

dards/wqslibrary/tribal.cfm.