EPA Review and Approval of State and Tribal Water Quality Standards

This rule specifies that new and revised standards adopted by States and authorized Tribes after the effective date of today's rule become "applicable standards for Clean Water Act purposes" only when approved by EPA. To facilitate transition to this approach, standards in effect under State and Tribal law and submitted to EPA before the effective date of the new rule may still be used for Clean Water Act purposes, whether or not approved by EPA, until replaced by Federal water quality standards or approved State or Tribal standards.