Chillicothe Water Hardness & Quality Report (2026)

Chillicothe, Ohio, in Ross County — the Ross County seat and Ohio's first and third state capital (1800–1816), a historically significant city on the Scioto River in the Paint Creek valley, the heart of the Hopewell and Adena prehistoric Native American cultural center — receives its municipal water from the Chillicothe Water Works, which draws from the Scioto River at the Chillicothe reach. The Scioto River is the principal water supply for multiple south-central Ohio communities in the Columbus-Chillicothe corridor.

The hard 209.5 mg/L hardness and elevated TDS of 486.6 mg/L reflect the Scioto River watershed's substantial Devonian and Mississippian carbonate geology in south-central Ohio. The Scioto River drains the central Ohio till plain — a glacially smoothed landscape underlain by the Devonian Columbus Limestone and Delaware Limestone formations (fossiliferous Devonian platform carbonates), overlain by thick glacial till with abundant calcareous limestone and dolomite clasts. The Scioto watershed also drains the Mississippian sequence at its headwaters — the Cuyahoga Formation (shale) and Black Hand Sandstone — with carbonate spring contributions from the Devonian limestone platform along the Scioto valley walls. The combination of glacially derived carbonate soils and Devonian limestone bedrock drainage produces hard river water consistently in the Chillicothe reach.

At 209.5 mg/L, Chillicothe'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 Chillicothe homes with water heaters and dishwashers. The PFAS level of 8.2 ppt warrants a certified drinking water filter — the Scioto River corridor's paper mill and industrial heritage (the former Mead Paper mill in Chillicothe), the Chillicothe Correctional Institution and Ohio state industrial facilities, and the broader south-central Ohio Scioto Valley PFAS industrial legacy contribute to Ross County's supply PFAS background.