Case Histories

SALISBURY-ROWAN UTILITIES; NORTH CAROLINA

​

BACKGROUND

Salisbury-Rowan Utilities operates a conventional flocculation – sedimentation - filtration water treatment plant, with a ballasted sand clarifier. The plant historically experienced insufficient clarifier performance, resulting in carry-over turbidity, polymer residual and limited filter run times. Rain events placed additional stress on the plant’s performance.

​

SOLUTION

Our LowDoseTM software system was recommended by the consultant, after laboratory testing indicated the plant would benefit. LowDoseTM is chemical dosing software that incorporates pH control with accurate water temperature compensation, and zeta potential measurement. A full-scale demonstration was initiated in October 2021. Upon commissioning, the LowDoseTM system reduced the amount of coagulant necessary to remove turbidity and sucessfully eliminate polymer carry-over, resulting in a significant reduction of head-loss. It also extended filter run times by more than 50%. Additionally, because of the reduction in the amount of coagulant used, Salisbury-Rowan saved on the expense of 1) sludge disposal, 2) caustic, and 3) lime.

​

RESULTS

• Fully automated dosing

• Reduced coagulant demand

• Reduced filter head-loss

• Extended filter run time

• Improved recycle performance

• Improved dewatering

• Turbidity event mitigation

​