PART 131 — WATER QUALITY STANDARDS [ 40 CFR 131 ]PART131 — WATER QUALITY STANDARDS [ 40 CFR 131 ]Table of ContentsSubpart A — General Provisions§ 131.1 — Scope.[ Last FR update: 03/23/1995 ]§ 131.2 — Purpose.§ 131.3 — Definitions.[ Last FR update: 12/14/1994 ]§ 131.4 — State authority.[ Last FR update: 12/14/1994 ]§ 131.5 — EPA authority.[ Last FR update: 03/23/1995 ]§ 131.6 — Minimum requirements for waterquality standards submission.§ 131.7 — Dispute resolution mechanism.[ Last FR update: 12/14/1994 ]§ 131.8 — Requirements for Indian Tribes toadminister a water quality standards program.[ Last FR update: 12/14/1994 ]Subpart B — Establishment of Water QualityStandards§ 131.10 — Designation of uses.§ 131.11 — Criteria.§ 131.12 — Antidegradation policy.§ 131.13 — General policies.Subpart C — Procedures for Review andRevision of Water Quality Standards§ 131.20 — State review and revision ofwater quality standards.§ 131...