Ames Water Hardness & Quality Report (2026)

Ames, Iowa, the Story County seat — home of Iowa State University, one of the nation's leading land-grant universities — draws its municipal water supply from the South Skunk River via the City of Ames Water Treatment Plant, treating South Skunk River water for the Ames area. The Skunk River system drains the central Iowa glaciated prairie. Water hardness in Ames reaches 283.5 mg/L — classified as very hard, among the harder municipal supplies in Iowa.

Ames's very hard supply reflects the South Skunk River watershed's calcareous glacial and bedrock geology. The South Skunk River drains central Iowa's agricultural landscape — underlain by: the Quaternary Iowan and Wisconsin glacial till and loess (calcareous wind-blown silt and glacially deposited calcareous boulder clay — among the most calcareous soils in the Midwest, heavily derived from dissolution of the underlying carbonate bedrock during Pleistocene glaciation); and the Mississippian Burlington and Keokuk Limestones (highly reactive calcareous formations exposed in the Skunk River valley terraces). Central Iowa's agricultural landscape and calcareous Quaternary soils have been consistently leaching dissolved calcium into the Skunk River for millennia, producing the very hard 283.5 mg/L supply at Ames.

At 283.5 mg/L, Ames residents face significant hard water challenges. Scale deposits form rapidly on faucet aerators, showerheads, shower glass, and tile — monthly or bi-monthly descaling with citric acid solution is essential maintenance. City of Ames Water Treatment Plant consistently delivers water meeting all Iowa DNR and EPA Safe Drinking Water Act requirements.