Wilmington Water Hardness & Quality Report (2026)

The Cape Fear Public Utility Authority (CFPUA) supplies drinking water to Wilmington and surrounding areas in New Hanover County, North Carolina. Approximately 80% of raw water is sourced from the Cape Fear River at Kings Bluff, 25 miles upriver, and treated at the Sweeney Water Treatment Plant north of downtown Wilmington. The remaining 20% is drawn from Castle Hayne and Peedee aquifer wells across the service area, processed at the Richardson Water Treatment Plant in Ogden. Both plants feed the distribution system serving homes and businesses throughout the community.

The Cape Fear River watershed drains a broad basin through the coastal plain, picking up minerals from limestone and sedimentary formations. Groundwater from the Castle Hayne aquifer — formed in Tertiary coastal plain sediments rich in calcareous sands and limestone — and the Peedee aquifer add further mineral content through natural dissolution in subsurface flows. This mixed surface and groundwater geology produces a moderately mineralised supply, with dissolved solids reflecting prolonged carbonate interaction throughout the basin and aquifer layers.

At moderate hardness levels, Wilmington's water promotes scale buildup in pipes, water heaters, and fixtures, reducing efficiency and lifespan. Most affected are water heaters, dishwashers, washing machines, and faucets, where mineral deposits increase energy use and cleaning needs. Regular vinegar descaling, low-flow aerators, and magnetic descalers help mitigate effects; a water softener is recommended for optimal appliance performance. CFPUA's state-certified lab consistently meets EPA standards (B+ overall score), though 9 contaminants are detected, including legacy GenX concerns from the Cape Fear. Treatment at Sweeney and Richardson plants involves coagulation, sedimentation, filtration, and disinfection; PFAS monitoring continues post-industrial incidents.