Chattanooga Water Hardness & Quality Report (2026)

Chattanooga, Tennessee draws its municipal water supply from Tennessee American Water (a division of American Water), sourcing raw water from the Tennessee River at Chickamauga Lake — a Tennessee Valley Authority (TVA) impoundment created by Chickamauga Dam in Hamilton County. The Tennessee River at Chattanooga collects drainage from a vast watershed encompassing East Tennessee, North Carolina, Virginia, and Alabama, traversing the full Valley and Ridge physiographic province before reaching the city. Raw water is treated at Tennessee American Water's Moccasin Bend Water Treatment Plant on the river. Water hardness in Chattanooga measures 233.5 mg/L — classified as very hard.

Chattanooga's very hard supply reflects the rich carbonate geology of the Tennessee River valley through the Great Valley of East Tennessee. The river at Chattanooga flows directly through the heart of the Valley and Ridge province — where sequences of Ordovician Chickamauga Limestone, Knox Group Dolomite, Cambrian Conasauga Limestone, and Cambrian Rome Formation form alternating ridge and valley topography across East Tennessee. These ancient marine carbonate formations dissolve readily into river water and groundwater throughout the watershed, producing very high calcium and bicarbonate concentrations in the Tennessee River system at Chattanooga.

At 233.5 mg/L, Chattanooga residents face significant limescale challenges. Showerheads and faucet aerators accumulate heavy white deposits within weeks — monthly descaling with acid solution is a recommended routine. Dishwashers leave persistent white film on glassware without rinse-aid, and kettle heating elements scale noticeably between uses. Water heaters experience significant element scale build-up requiring annual professional descaling or DIY maintenance. A whole-house scale inhibitor or ion exchange softener is a practical investment for Chattanooga households seeking to protect appliances and extend their operational life.