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1 v <br /> 1 A S S Q C k A T E S I N C <br /> i <br /> • Radius of influence of groundwater extraction; <br /> • Groundwater drawdown; <br /> 1 • Hydrogeologic properties of the aquifer; <br /> • Mass extraction rate of groundwater. <br /> 1 The scope of work for the pilot test consisted of extraction of groundwater from monitoring well <br /> EW-1 for approximately 6.5 hours, and monitoring the changes in groundwater level in extraction <br /> well EW-I and observation wells GMX-1 and MW-2 through MW-4. <br /> 1 3.1 Groundwater Pumping Test Methods o s and Procedures <br /> 1 The aquifer test was conducted on January 29, 2002 over an approximate 6.5-hour period by <br /> extracting groundwater at a generally constant rate from well EW-l. The test was performed to <br /> ' determine the aquifer properties and the radius of influence for groundwater pumping. <br /> Prior to initiating groundwater pumping, water levels were measured in each site well. <br /> 1 Measurements were collected manually using water level probes capable of measuring depths to <br /> one-hundredth of a foot (0.01 feet). Depth to water measurements at the beginning of the pump <br /> test are shown on Table 1. Prior to initiating the test, ATC placed dedicated water level probes in <br /> the extraction well EW-1 and observation wells GMX1, MW-2, MW-3, and MW-4 to measure <br /> the depth to water in the wells throughout the test. <br /> 1 The extracted groundwater was discharged into a 6,500-gallon polyethylene Baker Tank located <br /> approximately 80 feet north of extraction well EW-1. Pumping test field notes are contained in <br /> Appendix D. <br /> 1 3.2 Analysis of Groundwater Pumping Test Data <br /> 1 The constant discharge aquifer test is the most useful method to determine the aquifer parameters of <br /> hydraulic conductivity (K), transmissivity (T), and storage coefficient (S) in the water-bearing <br /> ' layer. The groundwater pumping rate during the pilot test, as measured by the flow meter, <br /> averaged approximately 13.54 gallons per minute (gpm), which over a 6.5-hour period yields <br /> approximately 5,280 gallons of groundwater extracted from well EW-1. The collected data were <br /> ' analyzed using AQTESOLVTm groundwater modeling software. <br /> 3_3 Analysis of Groundwater Pumping Test Data using AOTESOLVT" <br /> The aquifer parameters transmissivity and storage coefcient were calculated using AQTESOLVT"'' <br /> ft <br /> soware. Drawdown data were used in solving for the aquifer parameters. Data from four <br /> ' observation wells, GMXI, MW-2, MW-3, and MW-4, were used for analysis. Groundwater <br /> elevations measured during the test were recorded by water level probes and are contained in <br /> Appendix E with the AQTESOLVT"' input data. The aquifer thickness was assumed to be an <br /> average of 11 feet, based on approximate length of the water column in the well. <br /> w:125957Veportslpumptest.doc 3 <br />