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COUNCIL COMMUNICATION FORM <br /> PURCHASING& INTERNAL SERVICES MEMORANDUM <br /> December 9, 2020 <br /> TO: Honorable Mayor Moore Wolfe and City Council <br /> FROM: Scot Wrighton, City Manager <br /> Gregg Zientara, Financial Management Director <br /> Deborah M. Perry, Purchasing Supervisor <br /> SUBJECT: Bids for water treatment chemicals <br /> SUMMARY RECOMMENDATION: Staff recommends awarding contracts to the low bidders meeting <br /> specifications listed on Exhibit A for each of the water treatment chemicals for January 1,2021 —December <br /> 31, 2021. <br /> BACKGROUND: The following is a list of the chemicals and how they are used in the water purification <br /> process. <br /> Alum—to coagulate; clarifying agent <br /> Carbon—used for taste and odor control; control of atrazine and other compounds <br /> Carbon Dioxide—lowers the pH level <br /> Chlorine—primary disinfectant <br /> Hydrofluorosilicic Acid—reduces tooth decay <br /> Lime—water softening agent <br /> Sodium Chlorite—disinfectant; used for taste and odor control <br /> Sodium Hexametaphosphate — used to counteract calcium hydroxide; prevents scaling; filter <br /> protection <br /> The City of Decatur uses a performance based evaluation for Powdered Activated Carbon(PAC). <br /> Potential PAC bidders were requested to submit their PAC samples to an independent testing firm <br /> (Engineering Performance Solutions of Jacksonville,FL)to evaluate product performance. Three vendors <br /> submitted four products to evaluate. <br /> Each product was evaluated and assigned a performance factor based on its ability to remove 60% of two <br /> of the most commonly occurring substances attributed to the unpleasant taste and odor characteristics of <br /> drinking water—Geosmin and 2-Methylisoborneol(2-MIB). <br /> Multiplying this performance factor by the bid price submitted by each PAC vendor provided the ability to <br /> compare equivalent removal costs. The PAC product Aqua Nuchar from Ingevity Corporation was <br /> determined to be able to remove 60%of the Geosmin and 2-Methylisoborneol(2-MIB) at the lowest cost. <br /> (See Exhibit B for evaluation results). <br />