San Tan Valley
San Tan Valley, AZ water profile — supply sources, drought status, wastewater reuse, and the key water issues facing the city.
epcor - san tan
groundwater (wells) · private · PWSID AZ0411128
Below EPA's 15 ppb lead action level at last testing.
Source: EPA Safe Drinking Water Information System (SDWIS) · 2026 Q1
San Tan Valley is a small but growing city and the 17th-largest in Arizona, home to roughly 81,321 residents. San Tan Valley's drinking water comes largely from the same regional sources that serve Arizona: Colorado River, groundwater, and Salt & Verde rivers.
As elsewhere in Arizona, the central challenge is colorado river. A national leader in reuse — Scottsdale has demonstrated direct potable reuse — even as Colorado River cuts and groundwater limits constrain growth around Phoenix.
Arizona reuses an estimated 52% of its treated wastewater and maintains established reuse programs; San Tan Valley tracks moderate to severe drought conditions on the U.S. Drought Monitor scale.
Explore the Arizona profile for statewide context, or dig into the water issues shaping San Tan Valley below.
Pinal County water quality
Source: EPA SDWIS · 2026 Q1
At a glance
- Population ~81,321 (17th-largest in Arizona)
- Primary sources: Colorado River, groundwater, and Salt & Verde rivers
- Drought: moderate to severe conditions
- State reuse rate: ~52% of wastewater
Statewide drought history
% of Arizona in severe+ drought (Severe (D2) now).
Source: U.S. Drought Monitor
Common questions
Is tap water safe in San Tan Valley?
San Tan Valley's largest water system, EPCOR - SAN TAN, serves about 87,435 people. EPA records show 2 health-based violation(s) since 2016 and a most-recent 90th-percentile lead level of 0 ppb (EPA action level is 15 ppb). Always check your own provider's annual Consumer Confidence Report.
Where does San Tan Valley get its water?
EPCOR - SAN TAN draws primarily from groundwater (wells), part of Arizona's supply from Colorado River, groundwater, Salt & Verde rivers.
Related water issues
Colorado River
The river that supplies 40 million people has lost roughly a fifth of its flow since 2000, forcing a renegotiation of how seven states share the water.
ExploreGroundwater Depletion
Aquifers from the Central Valley to the Ogallala are being pumped faster than they recharge, causing land subsidence and threatening long-term supply.
ExplorePotable Reuse
Advanced purification turns treated wastewater into water that meets or exceeds drinking-water standards — increasingly essential in water-stressed regions.
ExploreDrought
Much of the American West is in a multi-decade dry period that researchers describe as the most severe in over a millennium, reshaping how communities plan for water.
Explore