Revised On: Oct. 5, 2023 - 9:30 a.m.

ADEQ evaluates each water source used by public water systems in Arizona. These evaluations assess the hydrogeology of drinking water sources to determine the quality of groundwater being drawn into wells, the watersheds supplying surface water and the surveyed land being used for activities occurring near drinking water sources.

This information is used to determine the degree to which a public drinking water source is protected from, or at risk of, contamination. It is also used to assist local communities in implementing source water protection measures.

Adjacent land uses within a specified proximity to a drinking water source, or the designated source water assessment area, are evaluated by ADEQ to determine if they are in fact posing a contamination risk. ADEQ has compliance information (occurrence data) on all public water systems in Arizona as well as many of the land uses found within drinking water source water assessment areas.

Because of this customized approach in studying each individual system, the source water assessment reports allow for better protection of drinking water and allow ADEQ to tailor monitoring requirements specific to each system where appropriate. For example, if a water system has no history of contamination by a particular chemical, as well as no potential for future contamination (based on land use practices and the risk they might pose to water sources), then monitoring relief or reduced monitoring for that chemical may be granted for that system. Another water system with a history of problems or the potential for contamination with the same chemical would still be required to monitor for that substance.

Source Water Protection Program

ADEQ assists public water systems, local officials, and utilities in developing and implementing plans to protect surface and groundwater resources by actively coordinating local pollution prevention efforts with existing state programs. Support available from ADEQ includes both assistance with program development and technical resources.

Benefits of establishing a source water protection program:

• Reducing the need to develop new drinking water sources and
• Reducing the costs for treatment of the drinking water to meet acceptable quality standards
  

The most successful source water protection programs involve public participation throughout the development of the program. ADEQ is available to provide guidance and technical assistance to the community in developing an effective program. With the emphasis on local public participation and direction during this development phase, the result will be local solutions to local problems.

Additional Resources

• Source Water Protection Infographic | View >
• Common Source Water Recommendations | View >
• Public Water System Requirements | Learn More >