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Lift Station Description <br /> This station is a wet -well mounted vacuum pump system mounted on top of a six foot diameter wet <br /> well. The station is located on the north side of Peltier Lake Drive and was constructed in 1977. <br /> The original lift station was supplied with two vacuum pumps rated for 550 gallons per minute at <br /> 54' total dynamic head (TDH). Due to the small size of the wet -well, the pumps would cycle <br /> excessively which caused the motors to bum out. The impellers were subsequently replaced with <br /> smaller impellers to reduce flow and increase run times for the motors. The existing impellers are <br /> rated for 100 gallons per minute at 36' TDH. The smaller impeller has solved the cycling problem <br /> by allowing the pumps to run longer each cycle. Heat build up in the motors is reduced by limiting <br /> the number of starts per hour for each motor. With the use of these smaller impellers, the existing <br /> 15 HP motor and impeller combination is running very inefficiently. In fact, the efficiency is below <br /> the lowest efficiency point on the pump curve and can only be assumed to be running somewhere <br /> below the 30% efficiency point. <br /> During the on -site inspection, the pumps were run manually to conduct the desired flow test <br /> experiment. One of the vacuum pumps could not be primed to conduct the test. After <br /> approximately twenty minutes of priming, the pump began to work and the test was conducted. The <br /> difficulty in obtaining and maintaining a primed condition is a very serious problem for this lift <br /> station. The pumps were flow tested and are currently pumping at the following rates. <br /> Pump No. 1 = 175 gpm, Pump No. 2 = 153 gpm. <br /> Pumping Records / Flows <br /> Lift station run times have been reviewed and tabulated from January 1997 through February 1999. <br /> The combined run times for both pumps has averaged approximately 4 hours per day throughout <br /> this period. This is not an excessive amount of hours per day. The station currently services <br /> approximately 150 homes during the time period listed above. An additional 50 homes are <br /> currently being added to this lift station by the Buechler Estates, Lakeland Hills and Woods of <br /> Clearwater Creek developments. Flows and run times will increase as these developments are <br /> completed. <br /> Lift Station Recommendations <br /> A. Equipment and Piping <br /> The equipment in this lift station has reached the end of its useful life. Therefore, at a <br /> minimum, it is recommended that the existing equipment be replaced with new submersible <br /> pumps. The existing concrete wet well is structurally in good condition and can remain in <br /> service as the wet well. Due to the style of the vacuum pump system, the top cover of the <br /> lift station will need to be replaced. We recommend the existing pumps be replaced with <br /> new submersible non -clog pumps with a minimum capacity of 250 gallons per minute at 42' <br /> TDH. <br /> B. Electrical Equipment <br /> The electrical equipment is in very poor condition and needs to be entirely replaced. It is <br /> recommended that a new above -grade electrical control panel be furnished and installed. <br /> Other electrical recommendations include a new service disconnect, replacement of the <br />