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Ms.Margaret Lagorio, SJCEHD October 21,2003 Joe's Truck Plaza Project No.2033-15600-01 Work Plan for Additional Site Assessment Page 12 the radius of influence (ROI) of the well at that pumping rate. A commonly used computer program, AQTESTPRO® (published by Waterloo Hydrogeologic), will be utilized to evaluate data generated during the GWE test. Groundwater extracted during the feasibility study will initially be discharged to an on-site storage tank. Based on permit conditions, the extracted groundwater will either be discharged to the sanitary sewer directly, or after treatment with granular activated carbon. Baseline Monitoring and Pretest Activity The baseline test will be performed for a period of approximately 8 hours. During the baseline test, a Stratus technician will set up pressure transducers and data loggers in the extraction well (EX-1), in shallow-screened monitoring wells MW-1, MW-2, MW-3, MW-7, MW-8, and MW-18, and in deeper-screened monitoring well DW-2 to measure changes in the groundwater elevations. The results of the baseline-monitoring period will help filter out the effects of ambient groundwater fluctuations that may be observed during the constant-discharge test and recovery period. The observation wells mentioned here will be used throughout the step discharge and constant-rate discharge test portions of the GWE test. Step Discharge Test After the baseline test is completed, a step discharge test will be performed using well with EX-1. Data collected from the step-discharge test will enable Stratus to estimate a sustainable pumping rate for the constant-discharge test, sufficient to stress the aquifer. An electric submersible pump, capable of achieving the anticipated pumping rates, will be temporarily installed in the pumping well for groundwater extraction. The extracted groundwater will be discharged through in-line flow meters and into the on-site storage tank. Flow rates will be measured during the step test by flow meters, and controlled with gate valves. Groundwater will be extracted from the pumping well (EX-1) at increasing discharge rates over several time periods, or steps. The step test will start at 0.5 gallons per minute (gpm) and will be increased by approximately 0.5 gpm per step. The anticipated duration for the step test will be approximately 8 to 10 hours, depending on the performance of the well. The drawdown response will be plotted against time and an appropriate pumping rate selected. If the water level in the test well does not change by more than 0.1 feet after 10 minutes of pumping for a particular step, the pumping rate for that step will be increased such that additional drawdown is induced. The flow rate for each step will be maintained P:\Joe's Truck Plaza\Work Plans\Joes workplan 102103.doc