Piqua Water Hardness & Quality Report (2026)

Piqua, Ohio, in Miami County — a Miami County city on the Great Miami River north of Dayton, the birthplace of aviation pioneer Orville Wright's era industrial Ohio, home of Hartzell Propeller and Emerson Climate Technologies manufacturing — receives its municipal water from the Piqua Water Treatment Plant, which draws from the Great Miami River at the Piqua intake in the upper Miami Valley, upstream of Sidney (both share the same Great Miami River supply system).

The hard 204 mg/L hardness and elevated TDS of 465.3 mg/L reflect the Great Miami River watershed's western Ohio dolomite geology at the Piqua reach — consistent with Sidney (210 mg/L, TDS 489) just upstream on the same river. The Great Miami River drains the Western Ohio Till Plain underlain by the Silurian Lockport Dolomite and Devonian Columbus Limestone — the Ohio dolomite platform that produces hard water throughout the upper Miami Valley. Thick Pleistocene glacial till rich in calcareous limestone clasts adds continuous carbonate dissolution input to the Miami River drainage throughout the year, producing consistently hard finished water.

At 204 mg/L, Piqua's water is hard — scale builds in kettles and appliances within weeks, dishwashers require rinse aid or softener salt, and bathroom fixtures develop calcium encrustation. Monthly descaling of heating appliances is practical. A water softener is recommended for Piqua households. The PFAS level of 8.0 ppt warrants a certified drinking water filter — Wright-Patterson AFB (Dayton — the US Air Force's primary research and logistics base and a major AFFF user) sits in the Great Miami watershed upstream from Piqua, and the broader Wright-Patterson PFAS contamination plume is a documented contributor to Great Miami Valley water supplies.