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WQD | Surface Water Monitoring & Assessment

Surface Water Quality Improvement Section

Monitoring and Assessment

Revised On: Oct. 25th, 2024 - 09:25 am

ADEQ's Surface Water Quality Improvement Section is responsible for administering state environmental laws and shares regulatory responsibility for Clean Water Act (CWA) programs delegated to the state from the U.S. Environmental Protection Agency (EPA).

ADEQ assesses the health of Arizona surface water quality to fulfill the requirements of the CWA and helps ensure this precious resource is protected today and for future generations. The health of Arizona waters are measured against criteria found in the Arizona Administrative Code Title 18, Chapter 11 | Learn more >

Status of Surface Water in Arizona

Every two years, the CWA § 305(b) and § 303(d) requires ADEQ to assess the health of Arizona surface waters against established standards. Following EPA guidance, ADEQ combines these requirements into an Integrated Report:

Data | View >

Note: Data acceptance for the 2026 Assessment closed on June 30, 2024.

Data | View >

Note: The 2028 assessment window is from July 1, 2021, to June 30, 2026.

If waters are not meeting the established surface water quality criteria, then the waters are considered impaired. Impaired Waters are shown on the CWA §303(d) list in the Integrated Report. If a water is impaired, ADEQ is required to identify sources of pollutants and provide solutions to restore the water quality. ADEQ calculates a Total Maximum Daily Load (TMDL) for each specific pollutant impacting an impaired water. The goal of a TMDL is to target pollutant sources to restore the health of the water | Learn More >

ADEQ also implements the state Surface Water Protection Program (SWPP) as defined in the Arizona Revised Statute Title 49, Chapter 2, Article 2. The SWPP requires ADEQ to publish a list of non-WOTUS state protected surface waters every five years. As of January 2023, there are no impaired non-WOTUS state protected surface waters.

Public Health and the Environment

Sources of pollutants can be point source, such as discharge from a facility, or nonpoint source, such as when stormwater runoff carries pollutants over land. There are multiple programs within ADEQ that protect surface water from pollutant sources, improve water quality and empower the public to make informed decisions, including:


Arizona’s designated uses and water quality standards are in the Arizona Administrative Code, Title 18, Chapter 11 | View >