Treatment package for surface water

Problem
The 0.5 mgd Hardy County (W.Va.) Public Service District Water Treatment Plant opened in 2012 to supply water to the city of Baker. Before consumption, surface water from the newly constructed Parker Hollow Reservoir needed treatment to remove turbidity, organic carbon, bacteria, and viruses. Additional considerations included seasonal fluctuations in solids and turbidity levels, and the state health department requiring an on-site demonstration.

Solution
Tonka Water conducted a pilot test using a packaged treatment system with a clean-in-place unit that pumped water from the reservoir to a twin unitized treatment system for chemical addition, flocculation, and sedimentation, and to dual ultrafiltration membrane skids for filtration and further contaminant reduction. Flocculation and settling occurred in a high-rate clarifier for the reduction and removal of iron, manganese, turbidity, and organics. The health department approved the system.

Result
The system reduced raw water turbidity from a range of 4.1 to 29 NTU to less than 0.1 NTU, iron from a range of 0.11 to 0.73 mg/L to less than 0.3 mg/L, and manganese from 0.68 mg/L to less than 0.05 mg/L, while increasing pH from a range of 5.1 to 7.1 to 7.8 to 8.2. The plant will accommodate the area’s growing population. 763/252-0896; www.tonkawater.com.