Covington Water Hardness & Quality Report (2026)

Covington, Kentucky, the Kenton County seat directly across the Ohio River from Cincinnati — a major Northern Kentucky city in the Greater Cincinnati area, home of the historic MainStrasse Village (a nationally recognized German heritage neighborhood and arts district), the Roebling Suspension Bridge (the John A. Roebling Bridge, completed 1867, the engineering prototype for the Brooklyn Bridge), and a rapidly revitalizing Northern Kentucky urban community with exceptional Cincinnati skyline views — draws its municipal water supply from the Ohio River via the Northern Kentucky Water District (NKWD). Water hardness in Covington measures 132 mg/L — classified as moderately hard.

Covington's moderate hardness reflects the Ohio River's calcareous Cincinnati Arch geology. The Ohio River at Covington–Cincinnati drains through: the Cincinnati Arch Ordovician carbonate sequence — the Ordovician Lexington Limestone (highly calcareous marine limestone — the same Lexington Limestone that underlies the Bluegrass horse country of Kentucky, named for its exceptional calcareous character); the Kope Formation (calcareous shale); and Silurian–Devonian calcareous formations of the Ohio Valley. The NKWD treatment plant reduces the Ohio River's inherent hardness to the moderate 132 mg/L at Covington.

At 132 mg/L, Covington residents encounter moderate scale accumulation. Monthly cleaning with citric acid solution is recommended. NKWD consistently delivers water meeting all Kentucky KDEP and EPA Safe Drinking Water Act requirements.