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Kim ey>>> Horn Page 10 This system includes a refrigerated storage and receiver tank and utilizes a Pressure Solution Feed (PSF) system manufactured by TomCO2 Systems® (Loganville, GA) to add carbonic acid solution to the clearwell. The PSF system injects pressurized CO2 gas into a side stream of pressurized degasified permeate to dissolve the CO2 into solution. This reaction generates H2CO3that is added into the degasified RO product water. Hobart and Oslo contain two PSF panels, each intended to be dedicated to a clearwell (Hobart) or clearwell bay (Oslo), two carrier water pumps to elevate the pressure of the water stream, and diffuser injection assemblies installed at the end of the degasifier down comer pipe. There is not a redundant PSF cabinet at either WTP. The PSF system, in conjunction with the pre-treated and acidified raw water blend, has demonstrated the ability to provide adequate buffering capacity with pH ranges of 5-5.5, pre lime addition. The lime slurry feed system is a proprietary system provided by Burnett, Inc. (Campobello, SC). The system includes a bulk storage tank, make-up water supply, mixer, and diaphragm pumps, and a patented lime slurry chemical. The system includes dedicated chemical feed lines to each degasifier bay and variable speed mixers to enhance the mixing and dissolution of lime slurry. The lime slurry system operates at a dosage setpoint with pH trim control via submersible probes installed at the end of the clearwell structure. Lime slurry is added to increase pH, add hardness, and form alkalinity with the buffering capacity provided by the TomCO20 system. The addition of calcium hydroxide, or lime, is a cost-effective finished water stabilization method. It provides enhanced stability in the water by increasing alkalinity and provides a more consistent method of forming a protective film on the interior surface of distribution system piping and components. Lime slurry has been used extensively in the water treatment industry for many years. It has been typically used for lime softening of hard waters and more recently as a finished water stabilization method of very soft waters, such as RO & NF permeate waters. Several installations in Florida are in operation at water treatment plants for stabilization of product waters. It is a relatively simple system and its operation is familiar to most water plant operators. The process generally consists of H2CO3 addition followed by lime slurry addition and mixing. H2CO3 is added to lower pH and enhance dissolution of the lime which increases the alkalinity of the blended stream. The lime slurry raises the pH, adds calcium hardness to the stream, and increases the alkalinity all at the same time. Photo 1 - Oslo Post -Treatment Facilities Photo 2 - Clearwell Weir 70