Water Quality

Most people in Maricopa County receive their drinking water from large municipal or public utility water delivery systems. The Drinking Water Program works to ensure that the water delivered by these Public Water Systems is clean and healthy and meets the standards prescribed by federal and state agencies.

Water in Maricopa County is Obtained From Three Primary Sources


Surface water from the Salt River Project or Central Arizona Project is treated by water treatment plants. Ground water is pumped from aquifers by wells. Drinking water produced by these water treatment plants or wells is delivered by the operator of Public Water Systems to the public.

Drinking Water Requirements


Water quality requirements for drinking water are written by the United States Environmental Protection Agency (EPA). These requirements are incorporated by the EPA into the Safe Drinking Water Act. The Drinking Water Program regulates Public Water Systems to ensure that they meet the requirements of the Safe Drinking Water Act.

Privately Owned Domestic Wells


Although most of the population in Maricopa County is served by a Public Water System, some people located in isolated or unincorporated areas of the County depend on privately owned domestic wells. The Drinking Water Program does not have the authority to regulate or monitor these wells. The owner of the well is responsible for ensuring the safety of the well and should take special precautions to ensure the protection and maintenance of their drinking water system. The Environmental Protection Agency's (EPA) has created the Private Drinking Water Wells web page to assist owners of privately owned domestic wells in determining if their well's water is safe.

Owners of privately owned domestic wells may contract with private companies for independent water testing. For the most up-to-date, information regarding testers currently certified by the Arizona Department of Health Services (ADHS) , please contact ADHS at 602-364-0724, or go to the ADHS's Arizona Certified Commercial Drinking Water Laboratories web page.