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A S S O C I A T E S I N C �. The aquifer parameters transmissivity and storage coefficient were calculated using AQTESOLV'M software. Drawdown data were used in solving for the aquifer parameters. Data from two observation wells MW2 and MW3 were used for analysis because based on the information obtained from the �- transducers placed in these wells, they showed significant drawdown during the aquifer test. Groundwater elevations measured during the test were recorded by transducers and are contained in Appendix E with the AQTESOLVTm input data. The aquifer thickness was assumed to be an average �- of 12.23 feet, based on approximate length of the water column in the wells. The Theis type-curve solution for a confined aquifer was used to estimate aquifer parameters. The results are presented in Table 3. The calculated storage coefficient indicates the aquifer exists in a partially confined condition. The storage coefficients for unconfined aquifers are typically between 0.01 and. 0.3, while those for confined aquifers are typically between 0.00005 and 0.005 (Driscoll page 210, 1986). The average storage coefficient calculated using the Theis solution was 1.7 E-3. The average hydraulic conductivity value (0.0027 meters per second [m/s]) calculated and presented in Table 3, fall within the average range for fine to coarse sand (1 to 10"5 m/s) (Driscoll page 74, 1986). Time versus drawdown plots for each well are presented in Appendix D. 3.4 Groundwater Sampling-and Analysis Grab groundwater samples were collected from well MW1 prior to beginning the pump test, after 24 hours, and at the completion of the pump test after the groundwater elevation had been allowed to recharge. Groundwater samples were transferred to appropriate sample containers, using clean, disposable bailers with bottom emptying devices to reduce volatilization. Sample containers were then labeled with sample identification, placed on ice, and shipped under chain-of- custody to State-certified Argon Laboratories for chemical analysis of TPHg, BTEX, and MTBE by EPA methods 801518020. Groundwater analytical results are summarized in Table 2, and �- laboratory data sheets are presented in Appendix A. 3_5 Results of Groundwater Pumping Test w The observed maximum drawdown in each of the observation wells was plotted against the * distance of each well from well MW1. Based on ATC's experience at groundwater remediation ` sites, the radius of influence is typically the point where the drawdown in the observation well is at least 0.10 feet. The maximum drawdown in well NM was 0.10 feet which yields a radius of influence (ROI) for groundwater extraction at the site of up to 85 feet (Figure 4). Laboratory results of the groundwater samples indicated that TPHg and benzene were detected in the samples collected from well MW1 before, at 24-hours, and after the pump test. Assuming 13,700 gallons of groundwater was extracted from well MW1, as stated in Section 5.2, and average concentrations of TPHg and benzene from the beginning, after 24 hours, and ending pump test samples, approximately 0.26 pounds of TPHg and 0.0008 pounds of benzene were removed per day during the groundwater extraction pilot test as shown below: v �. Concentration of TPHg in groundwater sample w:lwordproN14981\mTorts\pump_".doc 4 L.