Water Quality Standards Regulations: Arizona

Presented are water quality standards in effect for Clean Water Act (CWA) purposes for this state.

The EPA is posting these standards as a convenience to users and has made a reasonable effort to assure their accuracy. For each document listed under "State Standards in Effect for CWA Purposes", the EPA has made a reasonable effort to identify parts of the standards that are disapproved or are otherwise not in effect for CWA purposes. Additionally, please note the documents may also contain provisions that the EPA does not have the authority and duty to act on under the Clean Water Act because the provisions are not water quality standards.

• State Standards in Effect for CWA Purposes
• Federally Proposed or Promulgated Standards

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State Standards in Effect for CWA Purposes

• Title 18, Environmental Quality, Chapter 11, Department of Environmental Quality Water Quality Standards (2016) (pdf) (2.06 MB)
  (Effective October 26, 2022) State regulation establishing water quality standards for surface waters of the state. Please note that not all parts of this document are effective for CWA purposes.  Refer to the cover page for more information.
• Amendments to Title 18, Environmental Quality, Chapter 11, Department of Environmental Quality Water Quality Standards (pdf) (154.39 KB)
  (Effective July 3, 2003) Amendments to water quality standards for surface waters of the state.
• Implementation Guidelines for the Narrative Nutrient Standard (pdf) (2.07 MB)
• Implementation Guidelines for the State of Arizona Antidegradation Standard (pdf) (2.95 MB)
• Interim Whole Effluent Toxicity Implementation Guidelines for Arizona (pdf) (236.65 KB)

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Federally Proposed or Promulgated Standards

• 40 CFR §131.31  Arizona