The community of Stewartville was in need of a water treatment solution. Tonka Water, a U.S. Water Brand was selected as the equipment manufacturer for a new water treatment plant. The chosen process for softening is a complete integrated system consisting of membrane softening, with controls by Tonka Water. The new system includes a Flux™ RO membrane system consisting of an 8×4 membrane skid array that is expandable to 10×5 and a Clean In Place (CIP) skid, resulting in a full system flow rate of 460 gpm. The expandable skid allows for flexibility with future plant expansion.
The customized softening system utilizes the high pressure from the well pump to move water through the membranes, then on to distribution without the need for an additional feed pump. Where the feed pump would traditionally be located, a high service pump is used to increase permeate pressure to distribution. Raw water is directed into two streams: one stream utilized for blending, bypasses the Flux RO/NF™ membrane system, and the second stream feeds into the Flux RO/NF™ system for hardness reduction. The membrane bypass stream is then blended back with the more corrosive membrane effluent stream to form stable product water for consumption. A membrane bypass stream is often used to stabilize membrane permeate to protect the distribution system from aggressive water.
The Stewartville water treatment plant commissioned in 2014, continues to produce excellent results and meet expectations. Tonka Water is proud to have assisted the community in achieving its treatment goals.
|Influent Water||Blended Water|
|pH||6.0 – 7.5||7.11|
|TDS||291 mg/l||195 mg/l|
|Hardness||453 mg/l||100 mg/l|