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Potential Reinterpretation of a Clean Water Act Provision Regarding 

Tribal Eligibility to Administer Regulatory Programs

Prepared by the EPA Office of Science and Technology

May 2014

EPA took a cautious approach in 1991 when it interpreted a Clean Water Act (CWA) provision to mean 

that each tribe seeking to administer a regulatory program must demonstrate its own inherent 

regulatory authority. The demonstration has proven to be the most challenging and resource-intensive 

element of a tribe’s application to be treated in a manner similar to a state (“TAS”). Based on EPA’s 

experience and developments in the case law since 1991, EPA is considering a potential reinterpretation 

that could significantly reduce the burden on individual tribes applying for TAS.

I. CURRENT INTERPRETATION OF TAS PROVISION IN CWA 

In the preamble to a 1991 TAS regulation,1 EPA interpreted the CWA TAS provision at section 518 to 

mean that a tribe must demonstrate its inherent regulatory authority to be eligible to administer a 

regulatory program under the CWA. Further, where the tribe’s reservation includes nonmember-owned 

fee lands, the tribe generally must demonstrate that nonmember activities on nonmember-owned fee 

lands could have a substantial, direct effect on the tribe’s health or welfare – commonly known as the 

“Montana test.”2 EPA has issued guidance to tribes for complying with this interpretation when applying 

for the water quality standards program and section 401 certifications; a similar approach would be 

used for section 402 or 404 permit program applications.3

II. POTENTIAL REINTERPRETATION OF TAS PROVISION IN CWA

EPA is considering reinterpreting CWA section 518 as an express delegation by Congress to eligible tribes 

to administer CWA regulatory programs over their entire reservations irrespective of who owns the 

land. This would replace EPA’s current interpretation that an applicant tribe must demonstrate its 

inherent authority. The potential reinterpretation is supported by: the plain language of section 518; a 

similar approach applied in implementing the Clean Air Act TAS provisions; and relevant judicial cases 

and EPA’s experience since 1991. One effect could be a significant reduction in the time and effort for 

tribes to apply for and receive TAS. 

EPA would accomplish the reinterpretation by issuing an interpretive rule after soliciting and considering 

public comments. The interpretive rule would be accompanied by a revision to EPA’s current guidance 

for tribal applications. Neither the CWA statutory language nor EPA’s implementing regulations would 

be revised, since the language of both supports the proposed reinterpretation. A tribe would still need 

to identify the boundaries of the reservation areas for which it seeks TAS eligibility to administer a 

regulatory program, and EPA will still provide states, other appropriate governmental entities, and the 

public the opportunity to comment on the tribe’s assertion of authority before EPA approves or 

 

1 Amendments to the Water Quality Standards Regulation That Pertain to Standards on Indian Reservations, Final 

Rule, 56 FR 64895, Dec. 12, 1991.

2

See Montana v. U.S., 450 U.S. 544 (1981). 

3

See Strategy for Reviewing Tribal Eligibility Applications to Administer EPA Regulatory Programs, EPA, 2008, 

http://www.epa.gov/indian/laws/tas.htm, Attachments B and C
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disapproves TAS for the tribe. As with states, EPA will maintain oversight of any authorized tribal 

regulatory programs. EPA regulations also require states and authorized tribes to consider public 

comments before they act, such as when adopting water quality standards or issuing discharge permits.

III. STATUS OF THIS ACTION AND NEXT STEPS

During April-July, 2014, EPA is conducting pre-proposal consultation and coordination with tribes and 

states, consistent with relevant EPA and other federal policies. EPA welcomes the views of tribes and

states at this early stage, and is open to requests for further consultation opportunities.

EPA will fully consider all comments and views received during this consultation and coordination. If EPA 

decides to proceed, the interpretive rule could be proposed in the Federal Register in Fall 2014 with a 

comment period of 60 days to follow. The reinterpretation would not become effective until all 

comments are considered and the interpretive rule is finalized, likely not before Fall 2015. In the 

meantime, EPA will continue to implement the current interpretation of the CWA TAS provision.

IV. FOR FURTHER INFORMATION

 Further information on this potential action is available at 

http://water.epa.gov/scitech/swguidance/standards/wqslibrary/tribes_index.cfm.

 To ask questions or provide comments, please email Fred Leutner at 

TASreinterpretation@epa.gov or write: Corey Buffo, Chief, Regional, State, and Tribal Standards 

Support Branch (mail code 4305T), Office of Water, U.S. Environmental Protection Agency, 1200 

Pennsylvania Avenue, Washington, DC 20460.
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Potential TAS Reinterpretation 

Changes to Expect (shaded areas)

Current 

Interpretation

After 

Reinterpretation

Eligibility Criteria for TAS in CWA Sec. 518 and EPA regulations4-- the tribe 

must demonstrate that it...

1. Is federally recognized and has a reservation.

2. Has a governing body carrying out substantial 

governmental duties and powers

3. Has appropriate authority to regulate the quality of 

reservation waters.

 Tribe must provide a map or legal description of 

reservation boundaries

 Legal counsel must describe the basis of the tribe’s 

authority by...

Demonstrating

inherent 

authority and, if 

fee lands on 

reservation, 

meeting the 

Montana test

Relying on the 

Congressional 

delegation of 

authority

 Tribe must identify the surface waters to be regulated

4. Has (or has a plan for developing) the capability to 

administer the program

Review Processes – for a tribal Water Quality Standards program

 EPA seeks comments on tribal TAS application’s 

assertion of authority – from appropriate 

governmental entities, local parties (per § 131.8(c))

 EPA seeks comments on EPA’s factual findings 

concerning inherent tribal authority for TAS – from 

appropriate governmental entities, local parties (per 

EPA guidance)

Not needed

 Tribe seeks comments on its water quality standards 

before submitting to EPA for approval – from the 

public (per § 131.20)

 

4 The numbered elements are paraphrased from CWA section 518. The bulleted elements are 

paraphrased from selected provisions of EPA’s TAS regulations for regulatory programs: 40 CFR §§ 131.8 

(water quality standards), 131.4(c) (water quality certifications), 123.31-34 (section 402 permitting), and 

233.60-62 (section 404 permitting).