R2003-125 AUTHORIZING THE EXECUTION OF TASK ORDER NO.3

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\ Automatic shutoff actuators are available to automatically close the tapping valves on the chlorine ton containers if chlorine gas is detected in the chlorine feed room due to accidental discharge. Only actuators manufactured by Halogen Valve Systems, Inc. will be evaluated. The only modifications necessary to the e�sting chlorine feed system would be piping and tubing modifications to allow the actuators to be mounted directly on the ton container tapping valves. All piping and equipment downstream would remain unchanged. This evaluation will include costs for the automatic actuator systems, including controls, utilities, and the minor modifications to the piping at the ton containers. Engineer shall prepare a schematic to show the chlorine piping arrangement at the ton containers and the new actuators. New Sodium Hvpochlorite Storage and Feed Svstem Engineer sha11 perform a cursory evaluation for replacement of the existing chlorine storage and feed equipment with new sodium hypochlorite storage and feed equipment for drinking water disinfection. New sodium hypochlorite system equipment would include bulk storage tanks, transfer pumps, day tanks, metering pumps, piping, valves and controls. The new equipment sha11 be sized for storing and feeding a 12.5 percent solution of liquid sodium hypochlorite. On site generation of sodium hypochlorite, or storage and dilution of higher concentrations of sodium hypochlorite solution will not be evaluated. The new sodium hypochlorite system would be housed in a new building. The location for a new building will not be considered or determined in the evaluation. The cost opinion for the new building will be determined by multiplying the estimated building size by an � estimated unit cost per square foot plus an appropriate contingency factor. The expected impact of feeding sodium hypochlorite as a secondary disinfectant following primary disinfection with chlorine dioxide as it is currently practiced will be addressed. The evaluation will include costs for a complete sodium hypochlorite system, new building, utilities, modifications to the existing chlorine dioxide system, if required, and demolition of the existing chlorine equipment. The estimated annual chemical costs for year 2003 for feeding chlorine versus sodium hypochlorite will be compared. Engineer shall prepare a schematic of the hypochlorite feed system and a layout of the new building. B. REPORT Engineer shall prepare a report summarizing the findings of the evaluations. The report � A-3 City of Decatur Task Order No.3 Rev.07-25-03