All federally recognized Tribes have the ability to create their own water quality standards as well as air quality standards. This is according to the US Clean Water Act and Clean Air Act. In all but Oklahoma, the Tribes gain approval for their standards from the US EPA and States have little to no say in the matter. This is according to US federal Indian law. However, here is what Senator Inhofe did a few years back. TAS = Treatment As a State. WQS = water quality standards.
"Giving tribes no other choice is exactly what happened when the Pawnee Nation of Oklahoma gained TAS status and WQS program approval in 2004. Not surprisingly, a lawsuit was filed by the state challenging the EPA’s decision, and Oklahoma Senator James Inhofe, Chairman of the Senate Environmental and Public Works Committee, requested an investigation into the handling of TAS applications in the state. What came as a surprise, not only to the tribe but also to the EPA and the Governor of Oklahoma, was a midnight rider attached to a transportation bill after the House and Senate had agreed on the bill’s final version. Congress passed the Safe, Accountable, Flexible, Efficient Transportation Equity Act of 2005. Tucked away in subtitle B “Other Miscellaneous Provisions” is a short paragraph essentially stating that if Oklahoma gains approval to run state environmental programs, the EPA, on request of the state, must approve administration of the state program in Indian country located within the state “without any further demonstration of
authority.” The act also provides that the EPA may treat an Oklahoma tribe as a state only if, in addition to satisfying federal TAS requirements, the tribe and the state enter into a cooperative agreement. Oklahoma must agree to “treatment of the Indian tribe as a State and to jointly plan administer program requirements.”" (page 532-533)
One small paragraph in the midst of 10,000 page legislation stripped all Tribes in Oklahoma of their sovereignty by Inhofe.
The document from which the text is pulled is a great tribal water rights review.
http://www.wmitchell.edu/lawreview/documents/5.Sanders.pdf