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28 April 2005 <br /> AGE-NC Project No 97-0351 <br /> Page 10 of 11 <br /> 4 5 GROUND WATER MONITORING PROCEDURES <br /> Upon completion,the additional monitoring wells will be Included in the Five Star Manna ground <br /> water monitoring program, ground water sample collection will be performed in accordance with <br /> EHD guidelines (San Joaquin County Public Health Services Environmental Health Division Well <br /> Standards) and CVRWQCB guidelines (Tri-Regional Water Quality Control Board <br /> Recommendations for Preliminary Investigations and Evaluation of Underground Storage Tanks) <br /> 4 5 1 Static Water Level Measurements <br /> Before sampling and during ground water monitoring, static water level will be measured using an <br /> electric water level indicator Water level data will be recorded to the nearest 0 01-foot from a <br /> reference point marked at the top of the PVC well casing Before and after each use, the <br /> measurement device will be rinsed with water <br /> 4 5 2 Well Evacuation <br /> After measuring the depth to ground water and prior to sampling, the well will be purged using an <br /> inertia pump or a disposable bailer to ensure that the sample is representative of the formation,rather <br /> than standing water in the well casing The well will be pugged until 1)a minimum of three casing- <br /> water volumes have been removed from the well and/or 2) the field-measured ground water <br /> parameters, pH, temperature, and conductivity, have stabilized However, if a well is purged dry <br /> prior to evacuating three casing volumes, a ground water sample will be collected following <br /> 80 percent recovery of ground water within the well or after a minimum of 1 hour, but within <br /> 8 hours, of well evacuation <br /> 4 5 3 Sample Withdrawal <br /> Water samples will be collected from the monitoring well using a disposable polyethylene bailer or <br /> dedicated Teflon tubing used in conjunction with the inertia pump The bailers are disposed of after <br /> one use and require no decontaminating, the Teflon tubing used with the Inertia pump is either <br /> dedicated to each well or changed at each sampling event,thereby minimizing cross contamination <br /> due to sampling devices Samples will be drawn and collected in such a manner that agitation and <br /> exposure of the groundwater to the atmosphere is minimal <br /> 40 <br /> Advanced GeoEnvironmental,Inc <br />