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. --------.. A S S O C I ATE 5 INC . ATC discharged the extracted groundwater directl�to e City of Stocktonsewer system under an existing permit. The pumped groundwater was discharged into the sanitary sewer using an s access point approximately 30 feet north of well MW-3. Pumping test field notes are contained in Appendix B. 2_2 Analysis of Aquifer Test Data The constant discharge aquifer test is the most useful method to determine the aquifer parameters of hydraulic conductivity (K), transmissivity (T), and storage coefficient (S) in the water-bearing layer. The groundwater pumping rate during the pilot test, as measured-by-the-flow-meter, averaged approximately 3 gallons per minute (gpm) for the first half of thertest and 5.5 gpm for the second half s of the test. The collected data were analyzed using AQTESOLVTm-groundwater modeling:software and a recovery test analysis. r 2_3 Analysis of Aquifer Test Data using A TESOLVT' `. The aquifer parameters transmissivity and storage coefficient were calculated using AQTESOLVTm software. Drawdown data were used in solving for the aquifer parameters. Data from three observation wells were used for analysis because only wells MW1, MW3, and MW4 showed 4r r=;r significant drawdown during the aquifer test. Groundwater elevations measured in well MW5 showed no significant drawdown. Groundwater elevations measured during the test were recorded by transducers and are contained in Appendix D with the AQTESOLVTm input data. The aquifer E thickness was assumed to be an avof T7fe-ef based on approximate length of the water column in the wells. 7 { The Cooper-Jacob type-curve solutiotrfor--atr unconfined aquifer was used to estimate aquifer parameters. The results are presented in Table 5. Time versus drawdown plots using the Cooper- Jacob unconfined aquifer solution for each well are presented in Appendix E. The obtained results for the storage coefficient using the Cooper-Jacob solution were a little lower than expected for an unconfined aquifer. 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 .1- (Driscoll page 210, 1986). The average storage coefficient calculated using the Cooper-Jacob solution f was 0.0015. Although the storage coefficients were lower than expected, this method was considered f, appropriate for the site conditions. The average hydraulic conductivity values(0.001 meters per second [m/s]) calculated and presented in u Table 5, fall within the average range for fine to coarse sand(1 to 10"5 m/s)(Driscoll page 74, 1986). 2_4 Radius of Influence of A uifer Test The observed maximum drawdown in each of the four observation wells was plotted against the distance of each well from well MW-4. Based on the observed data, the radius of influence for w:%62574.02Veports\RPT-pump test.dw 4 F--