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Item No: 6 Meeting Date: February 1, 2010 Type of Business: Work Session Administrator Review: ____ City of Mounds View Staff Report To: Honorable Mayor and City Council From: Nick DeBar, PW Director / Mike Schnur, Lead Utility Worker Item Title/Subject: Discuss Upcoming Municipal Well Projects City Staff wanted to discuss and make the City Council aware of upcoming 2010 projects associated with the municipal wells. These projects are included in the adopted Capital Improvement Program. Municipal Well No. 1 and 2 Rehabilitation The City established a maintenance program whereby the wells would be evaluated and rehabilitated on a seven-year cycle. A longer period of eleven years was attempted; however, it was discovered that this period was too long to identify minor problems and correct them before they became major replacements. Well Nos. 1 and 2 were last rehabilitated in January 2003 and are now due for rehabilitation. Both wells draw water from the same aquifers. Well No. 1 has started to pump a larger amount of sand compared to historical trends and needs to be examined as to why this is occurring and take the necessary steps to correct the problem. If this problem is not corrected, deterioration of the well line shaft, coulomb pipe, and other well production parts will continue. In addition, the filter media in the Water Treatment Plant (WTP) tanks, which is used to treat the raw ground water, could be displaced which may result in a lower quality of water. Well No. 2 is also showing similar characteristics as Well No. 1, but not to the same severity as Well No. 1. Information on Well Nos. 1 and 2 are attached this report. The projected cost to rehabilitate Well Nos. 1 and 2 is estimated to be $60,000. Municipal Well No. 2 Motor Replacement Well No. 2 has an old natural gas motor that is not running smoothly when first turned on. This intermittent running results in cyclical spikes in the water pressure throughout the system, including the distribution piping and WTP, increasing the risks for water main breaks and treatment system component damage. This motor was purchased used and installed over 35 years ago. To adequately address the long-term needs of the well, a detailed analysis and evaluation needs to be performed to ensure proper sizing of pumps, motors, power supply, and water table drawdown. These services required specialized expertise and require hiring of outside consulting engineers and hydrogeologists. To assist in the analysis and evaluation of the well, Staff recommends only having the pump in Well No. 2 pulled and the well inspected as part of the rehabilitation of Well No. 1. The pump and associated piping would be reinstalled as part of a separate motor replacement project. This will allow adequate time to perform a well evaluation and proper motor/pump sizing to meet the current and future demands from the well. In addition, an evaluation will be performed to best manage emergency power to the well. The project cost to replace the motor for Well No. 2 is estimated to be $100,000.