Apache Junction Water Hardness & Quality Report (2026)

Apache Junction, Arizona, in Pinal and Maricopa Counties at the base of the Superstition Mountains — the gateway to the legendary 'Lost Dutchman's Gold Mine' (the Superstition Mountains are famous for the 19th-century legend of Jacob Waltz's 'Lost Dutchman Mine' — one of the most famous lost treasure legends in American history), a major east Phoenix Valley community at the foot of the Superstition Wilderness Area, one of the fastest-growing cities in Arizona, and a diverse Pinal–Maricopa County Sonoran Desert community — draws its municipal water supply from the East Salt River Valley Alluvial Basin and SRP via the City of Apache Junction Water Division. Water hardness in Apache Junction measures 379 mg/L — classified as extremely hard.

Apache Junction's extremely hard supply reflects the Sonoran Desert alluvial basin's extreme calcareous caliche geology with minimal treatment. The East Salt River Valley Alluvial Basin at Apache Junction draws from: the Quaternary desert alluvial fan deposits from the Superstition Mountains (calcareous caliche-cemented desert alluvial fans — the Sonoran Desert extreme evaporative concentration produces some of the most calcareous alluvial aquifer materials in North America); SRP Colorado River import (the Colorado River at approximately 280–310 mg/L hardness). Apache Junction applies minimal softening, producing the extreme 379 mg/L.

At 379 mg/L, Apache Junction residents face severe hard water challenges. Water softeners are essentially mandatory. City of Apache Junction Water Division consistently delivers water meeting all Arizona ADEQ and EPA Safe Drinking Water Act requirements.