Laserfiche WebLink
M � <br /> Section 2 <br /> Proposed Hydrogeologic Investigation <br /> 2.1 PURPOSE OF HYDROGEOLOGIC INVESTIGATION <br /> Groundwater and surface water monitoring will be conducted with the purpose of establishing <br /> background groundwater quality prior to potential impacts associated with proposed wastewater <br /> disposal activities. This hydrogeologic investigation will be conducted including quarterly <br /> groundwater and surface water(San Joaquin and irrigation water where applicable)monitoring <br /> over approximately one year and consisting of the constituents listed below. <br /> 2.2 GROUNDWATER AND SAN JOAQUIN RIVER MONITORING <br /> 2.2.1 GROUNDWATER AND SAN JOAQUIN RIVER ELEVATION MONITORING <br /> Groundwater level elevation monitoring will be conducted over four quarters using data logging <br /> equipment installed in the new wells. These data loggers will be programmed to record <br /> groundwater elevation measurements every 60 minutes. The absolute pressure measurements <br /> collected will be corrected for barometric pressure. Groundwater elevations will be recorded <br /> every 60 minutes. During each sampling event, groundwater elevation will be recorded quarterly <br /> using an electronic sounder. Water level data will be downloaded on a quarterly basis in <br /> conjunction with water sampling. During the first three months, the new data logging equipment <br /> will be downloaded monthly to check for proper operation. During the same period of <br /> groundwater elevation monitoring, the river stage at the Mossdale Bridge gauging station on the <br /> San Joaquin River will be obtained from the California Data Exchange Center for use in <br /> evaluating possible correlation between river stage and adjacent groundwater elevations. <br /> 2.2.2 GROUNDWATER AND SAN JOAQUIN RIVER WATER QUALITY MONITORING <br /> Groundwater monitoring wells and surface water will be sampled on a quarterly basis for one <br /> year. Monitoring well sampling will be conducted utilizing low flow sampling,purging of three <br /> well volumes, or other Regional Board approved method. Samples will be drawn after purging <br /> the monitoring wells and pH, temperature, and electrical have conductance stabilized. <br /> Groundwater oxidation-reduction potential (ORP)will also be monitored during well purging. <br /> Field data logs will be kept similar to the template provided in Appendix B. Samples will be <br /> collected according to EPA sampling protocols and stored in coolers and iced for shipment to a <br /> State Certified analytical laboratory. All samples for metals analysis will be first field filtered <br /> using a 0.45 µm filter prior to nitric acid preservation to obtain dissolved fractions of the <br /> constituents of interest. Additionally,based on the past uses and known discharges at the Deuel <br /> Vocational Institute, volatile organic compounds (VOCs) and semi volatile organic compounds <br /> (SVOCs) should also be assessed in groundwater only. The following analysis will be <br /> May2006 Main Stone Property <br /> 2-1 Effluent Storage and Disposal Site Hydrogeologic Ir mfigafion Workplan <br />