Quantifying a Year of Success: An Innovative Approach for Using Nanofiltration Concentrate to Augment Reclaimed Water Supplies

The Loxahatchee River District reuse program, founded in 1983, provides nearly 7 mgd of reclaimed water to residential communities, golf courses, parks, and recreational facilities in both Palm Beach and Martin County, Florida. Because of the growing demand for reclaimed water in the service area, the District increased its supply of reclaimed water by blending the concentrate stream from a neighboring nanofiltration water treatment plant and producing a blended reclaimed water to serve its reuse customers. Water quality data for chlorides, total dissolved solids, and sodium adsorption ratio are presented and discussed over the initial 14 months of blending operation. The additional 3 mgd of reuse water supply gained by the District resulted in an increase in annual revenue, as well as the cost avoidance of constructing a deep injection well that would have otherwise been required for disposal of the concentrate stream.