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� v �o I A S S O C I A T E S I N C The scope of work for the pilot test consisted of extracting groundwater from monitoring well MW-3 for approximately 48 hours, and monitoring the changes in groundwater level in well MW-3 and observation wells MW-1, MW-2, and MW4 through MW-6 3.1 Groundwater Purnping Test Methods and Procedures ' The aquifer test was as conducted on August 20 to 22, 2002, over a 48-hour period by extracting ' groundwater at a generally constant rate from well MW-3 The test was performed to evaluate aquifer properties and the radius of influence for groundwater pumping Prior to beginning the pump test, ATC personnel measured depth to water in all on-site wells and collected one ' groundwater sample from well MW-3 ATC also collected one groundwater sample from well MW-3 mid-way through the test and after the 48-hour pump test has been completed The groundwater samples were placed in an ice-chilled cooler and transported under chain-of-custody ' to a State-certified laboratory The samples were analyzed for TPHg by EPA Method 8015M and for BTEX and MTBE by EPA Method 8020A ' A pump equipped with a flow meter, totalizer, and discharge hose was installed into MW-3 During the test, ATC also placed transducers in MW-3 and in observation wells MW-1, MW-2 and MW-4 through MW-6 to measure and tabulate the depth to water in observation wells at one-minute intervals A submersible pump equipped with a flow meter capable of reading flows up to ten gallons per minute (gpm) and a discharge hose was installed in the groundwater extraction well ATC used a generator to supply power to the pump Groundwater was extracted from the well at average rate of 5 55 gpm for a period of approximately 48 hours and discharged directly to the sanitary sewer system, as approved by the City of Ripon The pump, discharge hose, and transducers were removed from the extraction well and the observation wells after completion of the pumping test Pumping test field notes are contained in Appendix A ' 3.2 Analysis of Groundwater Pumping 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 5 55 gallons per minute (gpm), which over a 48-hour period yields approximately 15,900 gallons of groundwater extracted from MW-3 The collected data were analyzed using 1 AQTESOLVTm groundwater modeling software and a recovery test analysis 3.3 Analysis of Groundwater Purnping Test Data using A TESOLVTM The aquifer parameters transnussivity and storage coefficient were calculated using AQTESOLVTm software Drawdown data were used in solving for the aquifer parameters Data from two observation wells MW4 and MW-6 were used for analysis because information obtained from the transducers placed in these wells, showed significant drawdown during the aquifer test Groundwater elevations S\Envcronment t1 626451reporU\p..p_test doc 3