Tribes and Water Quality Standards (EPA)Water quality standards (WQS) provide the regulatory and scientific foundation for protecting water quality under the Clean Water Act (CWA). WQS not only set water quality goals for a tribe’s water bodies, but also serve as the regulatory basis for establishing water quality-based treatment controls and strategies. To administer a WQS program under the CWA, a tribe must apply to EPA for authorization to be treated in a similar manner as a state (TAS). To learn more about WQS and coverage in Indian country, please refer to these resources.