Westerville Water Hardness & Quality Report (2026)

Westerville, Ohio, in Delaware and Franklin Counties north of Columbus — a major north Columbus suburban community, the home of Otterbein University (a United Methodist liberal arts university), historically the 'Dry Capital of the World' (Westerville was the headquarters of the Anti-Saloon League — the national organization that spearheaded Prohibition — from 1909 to 1934), a major Franklin–Delaware County Columbus north suburban community with excellent schools, and a diverse and growing Columbus north suburb — draws its municipal water supply via the Columbus Division of Water (CDW). Water hardness in Westerville measures 162.5 mg/L — classified as hard.

Westerville's hard supply reflects the central Ohio calcareous geology. The Hoover Reservoir on Big Walnut Creek at Westerville drains: the Devonian Delaware Limestone and Columbus Limestone (highly calcareous marine limestone of the Ohio carbonate sequence — the Delaware Limestone, named for neighboring Delaware County); the Silurian Niagaran Dolomite (highly calcareous dolomite of west-central Ohio); and the Wisconsin Age calcareous till (calcareous Erie Basin ice lobe glacial deposit). CDW's north Columbus distribution to Westerville produces the hard 162.5 mg/L.

At 162.5 mg/L, Westerville residents face regular hard water challenges. Monthly descaling with citric acid solution is standard maintenance. Columbus Division of Water consistently delivers water meeting all Ohio EPA and federal EPA Safe Drinking Water Act requirements.