AgdaPkt 2008-06-09 - Laserfiche WebLink

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5.28 Page 1 REPORT To the Honorable Mayor and City Council From the CrMat1:tt~r June 9, 2008 SUBJECT Final Acceptance - Red Morton Community Park Irrigation Well Drilling, Construction and Development RECOMMENDATION Accept, by motion, the Red Morton Community Park Irrigation Well and authorize the release of bonds and retention according to City procedures. BACKGROUND In March of 2004, the Redwood City Recycled Water Task Force (RCRWTF) recommended to Council that staff investigate the potential use of groundwater resources. As response, staff proposed drilling a pilot well in Red Morton Park to determine the feasibility of using groundwater, rather than potable water, for landscape irrigation in the park. In April of 2006, the City retained Geoconsultants, Inc. of San Jose, a groundwater exploration and development consulting firm, to perform a geological and geophysical survey at Red Morton Community Park to best determine the location of groundwater resources. Eight locations in the park were investigated and one location was identified as the most appropriate and promising site for a pilot well. In June of 2007, the City contracted with Wilkinson Enterprises Inc. of Half Moon Bay to drill a pilot well. The project has been completed although a useable groundwater source has not been located. Description of the work and results are as follow. . The depth for the well was originally 250 feet. At 180 feet, a formation of hard black shale was encountered which made drilling difficult. . At 230 feet, the drilling effort created an oily fluid as it released small amounts of naturally occurring oil present in shale. Drilling was stopped and the test hole was plugged t0165 feet with cement to prevent the oily fluid from reaching the surface. . At 165 feet, the pilot well was "sounded" to determine if groundwater was accessible at this depth. Geophysical exploration indicated the presence of a thirty five feet thick water bearing stratum. Based on this finding and a stratum of fractured rock found at a depth of 115 feet - 150 feet, the pilot well was constructed and a test pump installed. . The initial pump tests failed to realize any significant production capacity. In December of 2007, additional development work was performed that included an attempt to dissolve calcium bicarbonates and magnesium bicarbonates that inhibit well production by preventing the flow of water through fractured rock. . Another pump test was performed in January of 2008. The measured production of the well was too low, 0.06-0.07 gallons per minute, to be considered for further development. Staff directed the Contractor to abandon the pilot well according to California Department of Health Services requirements.