Increased potable water demands required rapid construction of a new water treatment plant on the base. The treatment system – which has a flowrate of 600-800 gallons per minute – was designed to treat well water to bring it into compliance with EPA drinking water standards.
The original design and specifications were based on limited data about the underground aquifer which was believed to underlie the proposed well site on the Ft. Stewart military base. Key parameters used in the design were as follows: Total dissolved solids (TDS) 1500-2000 ppm; silica 20-25 ppm; alkalinity 100-175 ppm; sulfates 290-320 ppm; total hardness and barium projections were not provided. Since the anticipated TDS level was significantly higher than the secondary EPA drinking water limit of 500 ppm, reverse osmosis was selected as the primary technology.
Reverse osmosis utilizes a semi-permeable membrane which allows passage of water molecules but prevents passage (i.e., “rejects”) 96-99% of dissolved minerals or chemicals from passing. These are discharged as wastewater. Typically, 25% of the RO feedwater is discharged as waste while 75% is recovered as “permeate.”
WaterProfessionals® recommended a solution that softened 50 percent of the raw water stream to reduce costs while it also lowered concentrations to a level that made antiscalant effective. After working with severe time constraints, and a challenging and changing raw water supply – WaterProfessionals® provided a reliable treatment scheme that created a finished well water that meets Federal EPA and State of Georgia standards.