We require that water quality standards adopted by states and authorized tribes on or after May 30, 2000 must be approved by EPA before they can be used as the basis for actions, such as establishing water quality-based effluent limitations or total maximum daily loads (TMDLs), under the Clean Water Act.

• Fact Sheet describing our revised regulation that specifies when new and revised State and Tribal water quality standards become effective.
• Federal Register Notice (April 27, 2000)
• Questions and Answers

Fact Sheet describing proposed regulation (June 1999)