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Item No. 5 <br />Meeting Date: July 7, 2008 <br />Type of Business: WS <br />City Administrator Review _______ <br /> <br />City of Mounds View Staff Report <br /> <br /> <br /> <br /> <br />To: Honorable Mayor and City Council <br />From: Steve Dazenski, Parks/ Public Works Supervisor <br />Item Title/Subject: Consider the Purchase of Grinder Pump for <br />Groveland Lift Station. <br />Background: <br />The pumps at Groveland Lift Station, located at 2815 Ardan Avenue, were <br />repaired in 2001 as a preventative maintenance procedure. In the following six- <br />plus years the pumps have again become worn and the tolerances are no longer <br />within recommended manufacturer specifications. In addition, the lack of a <br />grinder within the wet well allows bulk material (i.e. rags, diapers, condoms, <br />sanitary napkins etc.) to pass through and become lodged in the pump causing <br />further wear on the motors. <br />Discussion: <br />Due to the worn tolerances the pumping capacity is less than 80% of pumping <br />efficiency. This causes either both pumps running unnecessarily at the same <br />time or one pump running double time. Also, due to the worn tolerances the <br />aforementioned materials become lodged causing motor wear and forcing utility <br />workers to enter the dry well confined space to remove the material. The <br />estimated time spent removing the material is between 120-150 hours annually. <br />The estimated cost of this labor is between $5,280-$6,600 annually. The loss of <br />one pump has become commonplace in the last six-plus years, this routinely <br />occurs on weekends when no one is available to read the pumping reports. As <br />things stand right now, the best case scenario is that the City relies on the pumps <br />to alternate when one is shut down. In a worst case scenario, the loss of both <br />pumps would cause severe sewage back-up into the basement of households in <br />the vicinity. <br />Recommendation: <br />Staff has extensively researched solutions to rectify the problems with Groveland <br />Lift Station. Two specialists within the pump industry (Braun and General Repair <br />Service), have been on site to inspect the pumps and give their <br />recommendations. Both conclude that the pumps at Groveland Lift Station are in <br />need of repair and/or replacement. General Repair Service quotes a price of <br />$13,000+ to repair the pumps and $17,000+ to replace them. This will bring the <br />pumping capacity back to 100% but does not ensure elimination of bulk material <br />being lodged in the pumps.