Groundwater Quality Monitoring Program

Published on February 04, 2026

Why Monitor Groundwater?

Groundwater is a vital resource that serves a myriad of purposes, including irrigation, livestock, industry and drinking water. Approximately 1.5 million Arizonans depend on groundwater for drinking water, especially in rural areas. The Groundwater Management Act of 1980 underscored the importance of upholding strict water quality standards, mandating the classification of every aquifer in Arizona for drinking water use. This legislative mandate highlights the critical need to safeguard every aquifer as a potential source of drinking water. Outside of Maricopa County, groundwater is the primary source of the State’s drinking water supply. Our sampling efforts directly benefit more than 330,000 Arizonans who rely on private wells for drinking water and are responsible for testing their private wells.