Fayetteville Water Hardness & Quality Report (2026)

Fayetteville, Arkansas — home of the University of Arkansas and the Walton Arts Center in Washington County — draws its municipal water supply from Beaver Lake (a Corps of Engineers impoundment on the White River in Carroll and Benton Counties) via the Fayetteville Water and Sewer Department, treating White River/Beaver Lake water at the Smith Water Treatment Plant serving the Fayetteville metropolitan area. Beaver Lake is the principal water supply reservoir for northwest Arkansas. Water hardness in Fayetteville measures 102 mg/L — classified as moderately hard.

Fayetteville's moderate hardness reflects the Beaver Lake watershed's Ozark Plateau geology in northwest Arkansas. The White River drainage above Beaver Lake crosses: the Boston Mountains (Pennsylvanian Atoka Formation sandstone and shale — siliceous, limited carbonate); the Springfield Plateau (Mississippian Burlington and Keokuk Limestone — substantial carbonate input); and the Salem Plateau (Ordovician Gasconade Dolomite — highly reactive dolomite contributing dissolved calcium and magnesium). The Springfield and Salem Plateau carbonate formations, particularly the Mississippian Burlington Limestone with its characteristic crinoidal composition, contribute moderate dissolved calcium to the White River–Beaver Lake supply before treatment.

At 102 mg/L, Fayetteville residents encounter moderate scale accumulation. Faucet aerators and showerheads develop deposits after several months — monthly cleaning with citric acid solution is practical maintenance. Dishwashers produce cleaner glassware with rinse-aid. Fayetteville Water and Sewer Department consistently delivers water meeting all Arkansas DEQ and EPA Safe Drinking Water Act requirements.