AgdaPkt 2010-04-12 - Laserfiche WebLink

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6.1B Page 1 REPORT To the Honorable Mayor and City Council From the Ci Mana er April 12, 2010 SUBJECT Award of Contract - Sanitary Sewer Pump Station No. 12 Improvements Project RECOMMENDA liON Approve, by motion, the contract documents and award the standard form contract 00520 for the Sanitary Sewer Pump Station No. 12 Improvements Project to the lowest responsible bidder, Casey Construction, Inc. of Emerald Hills for their low bid of $420,325.00 and authorize the City Manager to increase the contract amount, if necessary, up to 100,10 of the amount awarded. BACKGROUND Redwood Shores currently has a total of 26 sewer pump stations. Over the past ten years, the city has made improvements to sanitary sewer pump stations 1, 2, 3, 10, and 15 to improve the pumping efficiency, ease of operation, and safety of the facility. Pump stations are selected for improvements after Engineering and Public Works Services staff evaluate the condition of the existing facilities. As well as the overall functionality of the pump station, the evaluation includes issues of safety, maintenance and operation efficiency, and the ability of the facility to perform in emergency conditions. Pump Station No. (&IPS") 12 was constructed in the early 1980's and is one of city's more critical facilities as it receives and directs flows from five other pump stations (Centrum, PS 1, PS 2, PS 11 and PS 25). The flows from PS 12 are pumped to PS 10 via a recently installed 12-inch diameter PVC force main completed in late 2009. PS 12 was originally designed as a separate dry and wet well, which was a common configuration at the time. However, that configuration has since become a safety concern since it requires maintenance staff to descend 20 feet into a confined space that may contain hazardous gases to replace or service the pumps. As well, the existing facility does not have a permanent emergency power source. The project is designed to improve the safety of the facility and to insure that adequate flows can be maintained during an emergency. Improvements will include installation of two new and larger 30 horsepower submersible pumps that attach to guide rails. This allows the pumps to be raised and lowered for servicing which eliminates the need for maintenance staff to descend into the wet well. Other improvements include new variable speed drive controls which will increase the efficiency of the pumps, new piping, rehabilitation of the wet well's interior surface which will extend the useful life of the station, and a permanent emergency standby engine generator which will replace a portable engine generator to ensure continuous service of the pump station in the event of power failure.