Tonka Water received a water treatment challenge from Hardy County, West Virginia for water supplied to the City of Baker from the newly constructed Parker Hollow Reservoir. This surface water source required removal of turbidity, organic carbon, bacteria, and viruses, all subject to seasonal fluctuations. Tonka Water needed to provide a system that met all requirements and earn approval by the West Virginia Health Department with an on-site demonstration.
Tonka Water conducted an on-site pilot utilizing flocculation and settling with a high-rate clarifier for the reduction and removal of iron, manganese, turbidity, and organics. The pilot demonstrated that the treatment plant would satisfy Health Department requirements and was approved.
A packaged treatment system was proposed by Tonka Water, pumping water from the reservoir to a Unitized Treatment System (UTS™) for chemical addition, flocculation, and sedimentation, and to U-Flex™ Ultrafiltration Membranes for filtration and further contaminant level reduction. The complete system includes twin UTS™ units, two U-Flex™ membrane skids, and a CIP system.
Hardy County Public Service District’s Water Treatment Plant opened in 2012 and is capable of producing more than 500,000 gallons of high-quality drinking water per day, ensuring it will accommodate the area’s growing population.
The Tonka Water U-Flex™ membrane system at Hardy County includes Dow™ membranes with controls for automated backwash, chemically enhanced backwash and integrity testing. Additional features include individual module isolation, in-place module repair, and cloud-based control enabling data back-up, remote monitoring, and operation.
Water is pumped from Parker Hollow Lake, into the UTS™, where chemical addition, flocculation and sedimentation occur. The clarified water is pumped through a disc pre-filter, which removes solids that can damage membrane fibers. As the pre-filtered water then flows through the U-Flex™ membrane modules packed with hollow fiber membranes. Water flows from the outside to the inside through the hollow fibers to remove remaining contaminants and provide 4-log removal of giardia and cryptosporidium. Treated water is stored in a clear well and chlorinated prior to distribution to the residences and businesses of Baker. Approximately 96 percent of the water treated by the Pore-Flex™ system flows to the distribution system. The balance is used for periodic cleaning of the membranes.
Water analysis shows the U-Flex™ system producing high quality drinking water as shown below.
|Turbidity||4.1 – 29 NTU||<0.1 NTU|
|Iron||0.11 – 0.73 mg/L||<0.03 mg/L|
|Manganese||0.68 mg/L||<0.05 mg/L|
|pH||5.1 – 7.1||7.8 – 8.2|