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The extracted groundwater will be stored in a Baker tank(s), but the volume that will be <br /> withdrawn will depend on the pumping rate,which is unknown at this time. At a rate of 8 gpm, <br /> for example, 5,760,gallons would be pumped. <br /> The drawdown data from observation wells against time will used to determine the coefficient <br /> of transmissivity(T)along with other paameters to estimate such things as radius of influence, <br /> hydraulic conductivity(K) and coefficient of storage(S). Figures 2 and 3 are two examples of <br /> the methods that were used on a site in Napa County for determining transmissivity. <br /> 3.0 PROCEDURES <br /> The procedures that will be used in this investigation are listed below: <br /> Notify San Joaquin EHD at least 48 hours prior to field work. <br /> 3.1 Step test <br /> 1. Begin pumping at 4 GPM from GT-10 and adjust the pump intake so that it is placed <br /> within a foot of the drawdown. <br /> 2. Maintain this rate for about one hour and obtain a water sample from the stream near <br /> the end of the hour. <br /> 3. Collect groundwater samples in sterilized EPA vials and place in a cooled ice chest. <br /> 4. Then, increase the flow by about 4 GPM(adjusting the well intake to account for the <br /> increased drawdown) and repeat step 2. <br /> 5. Incrementally increase the pump rate until the maximum pump rate or formation yield <br /> is achieved. <br /> 6. Store removed water in Baker tank for later disposal. <br /> 7. Transmit water samples to McCampbell Laboratories for analysis of the following: <br /> Total petroleum hydrocarbons(gasoline and diesel)(EPA 602) <br /> 3.2 Constant Rate Pump Test <br /> 1. Pump from GT-10 at a constant rate as determined by the step test for 12 hours. <br /> 2. Measure groundwater elevations at periodic intervals from the extraction and observation <br /> wells. <br />