Schertz Water Hardness & Quality Report (2026)

Schertz, Texas, in Guadalupe County northeast of San Antonio — one of the fastest-growing cities in Texas, a major San Antonio northeast suburban community in the rapidly expanding I-35 corridor (Schertz–Cibolo–Universal City area), adjacent to Randolph Air Force Base, and a diverse Bexar–Guadalupe County community — draws its municipal water supply from the Edwards Aquifer and GBRA supply via the City of Schertz Water Division. Water hardness in Schertz measures 189.5 mg/L — classified as hard.

Schertz's hard supply reflects the northeast San Antonio Edwards Plateau calcareous geology. The Edwards Aquifer — the primary water source for the San Antonio region — is hosted in the Cretaceous Edwards Limestone and Georgetown Limestone (highly calcareous marine limestone and dolomite of the Texas Hill Country). Schertz also receives supplemental supply from the GBRA Guadalupe River (moderately calcareous limestone watershed of the Texas Hill Country). The calcareous Edwards Limestone karst dissolution and calcareous Guadalupe River watershed produce the hard 189.5 mg/L at Schertz.

At 189.5 mg/L, Schertz residents face regular hard water challenges. Scale deposits form on faucet aerators, showerheads, and appliances within weeks — monthly descaling with citric acid solution is standard maintenance. City of Schertz Water Division consistently delivers water meeting all Texas TCEQ and EPA Safe Drinking Water Act requirements.