R2001-75 AUTHORIZING THE EXECUTION OF AN AN AGREEMENT

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Mr. Keith D. Alexander City of Decatur Page 3 _ March 27, 2001 6. Additional Required Capacity Evaluate the adequacy of the existing water supply facilities using the water demands developed. Summarize the need for added raw water supply, treatment capacity, pumping, and storage facilities. The need for additional capacity will be documented along with possible alternatives. 7. Water System Modeling a. Add all pipes 6 inches and over in diameter near the South Water Treatment Plant (SWTP) and existing elevated tanks to the existing WaterCAD 4.1 model, permitting more accurate evaluation of potential main improvements near the SWTP and existing elevated tanks. b. Conduct 15 additional field fire flow tests and a computer model calibration check within the SWTP and elevated tank areas. Work with the OWNER to evaluate the known calibration problem at node 13. c. Work with the OWNER to conduct a field and computer calibration check of the model after the North Water Treatment Plant has been taken off-line. d. Conduct a sensitivity study of the impact of three variable ADM demand rates on the existing and proposed water system. e. Evaluate the water distribution system under three expanded treated water supply conditions. This will include (1) expansion of the SWTP, (2) a new water treatment plant at an approximate location to be determined during discussion with the OWNER, and (3) one additional supply condition to be determined during the study with the agreement of the OWNER. f. Prepare a list of water main improvements needed in the service area. List main improvement that can provide service under all three water supply conditions. g. Conduct a preliminary review of water main routes for new main. This will include consideration of the Decatur Street Improvement Program. h. Include a new south elevated tank in the water distribution system evaluations. The function of the proposed south elevated tank will be evaluated under all three proposed supply conditions. i. Evaluate alternative means of providing adequate service pressure in the areas in northwestern Decatur that now experience marginal pressures during high demand days. j. Prepare an estimate of water age in the distribution system main and storage under existing and one future demand condition. Discuss the implications of water age on Trihalomethane production in the distribution system. MGO:jIi\\\SA 1\VOL 1\CORPDATA\WORDP\AGR\Decatur.Agr1-624-009.doc STRAN D ASSOCIATES,INC.