Water Quality Division: Monitoring and Assessment

The program fulfills Clean Water Act requirements for water quality monitoring and assessments. Specific activities include providing critical information on water quality conditions, establishing water quality standards, and developing water quality management plans called TMDLs. The program uses a Total Maximum Daily Load, or TMDL, process to address pollution problems within watersheds.

See Also:


Arizona's Integrated 305(b) Assessment and 303(d) Listing Report describes the status of surface water in Arizona in relation to state water quality standards. The report contains a 303(d) list of Arizona's impaired surface waters requiring the development of a Total Maximum Daily Load (TMDL) and fulfills requirements of the federal Clean Water Act sections 305(b) (assessments), 303(d) (impaired water identification), and 314 (status of lake water quality).

The Draft 2012/14 Status of Water Quality Arizona’s Integrated 305(b) Assessment and 303(d) Listing Report is now available. A 45-day comment period ended June 16, 2014. ADEQ is revising the Integrated Report and will publish a 45-day Public Notice in the Arizona Administrative Register prior to submitting the 303(d) List to EPA for approval.

The 2010 Status of Water Quality in Arizona 305(b) Assessment Report has been broken down into sections for easier viewing and downloading.

NOTE: This report does not provide information about the quality of water being provided by Arizona's public drinking water systems. See Safe Drinking Water for more information.

Impaired and Not Attaining Waters Lists - The 2010 303(d) has been approved by EPA and is now final.


ADEQ monitors the ambient water quality in streams, lakes and groundwater throughout the state. Information obtained from ambient monitoring is used to develop water quality standards and to inform the public about Arizona's water quality. Water quantity issues are handled by the Department of Water Resources.

Arizona's Comprehensive Water Quality Monitoring Strategy - For Fiscal Years 2007 to 2017

Ambient River and Stream Monitoring

Ambient Lake Monitoring

Ambient Groundwater Monitoring