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` v *kTc A S S O C I A T E S I H C L_ The scope of work for the pilot test consisted of extraction of groundwater from monitoring well MW 1 for approximately 48 hours, and monitoring the changes in groundwater level in well MW i and observation wells MW2 and MW3. 3.1 Groundwater Pumping Test Methods and Procedures L The aquifer test was conducted on July 16, 17, and 18, 2002 over a 48-hour period by extracting groundwater at a generally constant rate from well MW l. The test was performed to determine ` the aquifer properties and the radius of influence for groundwater pumping. V Prior to beginning the pump test, ATC personnel measured depth to water in all on-site wells and collected one groundwater sample from well MW1. ATC also collected one groundwater sample from well MW 1 mid-way through the test and after the 48-hour pump test has been completed. The groundwater samples will be placed on ice and transported under chain-of- custody to a State-certified laboratory. Samples were analyzed for TPHg and BTEX by EPA method 8015/8020 and for MTBE by EPA Method 8020. r` A pump equipped with a flow meter, totalizer, and discharge hose was installed into well MW1. During the test, ATC also placed transducers in well MWl and in observation wells MW2 and MW3 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 10 gallons per minute (gpm) and a discharge hose was installed in the groundwater extraction well. ATC uses a generator to supply power to the pump. Groundwater was extracted from the well at average rate of 4.76 gpm for a period of 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 with the completion of the pumping test. Pumping test field notes are contained in Appendix B. 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 4.76 gallons per minute (gpm), which over a 48-hour period yields approximately ` 13,700 gallons of groundwater extracted from well MW 1. The collected data were analyzed using AQTESOLVT"groundwater modeling software and a recovery test analysis. 3_3 Analysis of Groundwater Pumpin2 Test Data using A TESOLVTM wAwordpro1149811re mU\pump_teskdoc 3 L..