Hendersonville Water Hardness & Quality Report (2026)

Hendersonville Utility District (HUD) provides drinking water to the city of Hendersonville and surrounding areas in Sumner County, Tennessee, serving over 60,000 residents. The utility sources all of its water from Old Hickory Lake, a surface water reservoir impounded on the Cumberland River. Water is drawn at an intake near Rockland Park and treated at the HUD Water Treatment Plant through conventional processes including coagulation, sedimentation, filtration, and disinfection. No groundwater or mixed sources are used.

The Cumberland River watershed spans over 18,000 square miles, originating in the Appalachian Plateau and flowing through the Nashville Basin karst region. Key geological features include Ordovician and Mississippian carbonate formations such as the Cynthiana Shale, Lexington Limestone, and Warsaw Formation, which are prone to dissolution and mineral leaching. Old Hickory Lake lies within this limestone-influenced basin, where surface runoff and river flow interact with carbonate bedrock, enriching the water with dissolved minerals and giving it a moderately hard character typical of Central Tennessee surface supplies.

At moderately hard levels, limescale buildup in pipes, heaters, and fixtures reduces efficiency in water heaters, dishwashers, and washing machines by up to 20–30%, with spotting on glassware and soap scum common. Regular maintenance including deliming heaters annually and vinegar soaks for faucets helps mitigate effects; a water softener is often recommended for households to prevent scale and improve cleaning efficiency. HUD's water meets all EPA standards with no violations noted; pH is typically neutral around 7.5, lead and copper levels comply via corrosion control, and trace disinfection byproducts like bromodichloromethane are detected above health guidelines but remain below MCLs.