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Workplan for Completion of an Aquifer Test 16 South Cherokee Labe, Lodi, California ' 2.1 Preliminary Pump Test ' A preliminary pump test will be performed prior to conducting the full-scale constant-rate aquifer test This preliminary test will be used to determine acceptable pumping rates (well yield), maximum anticipated drawdown in the extraction well, and to ensure that location ' of observation wells are appropiate to observe sufficient drawdown and produce useable data 2.2 Constant-Rate Aquifer Test The constant-rate aquifer test will be conducted a minimum of 24 to 48 hours after the ' completion of the preliminary pump test to allow for the water table to return to its static water level tBased on previous groundwater sampling results and well construction data, GeoAudit proposes to utilize Well EW-1 as the extraction well for the constant-rate aquifer test (Figure 2) Historically, six of the fifteen existing wells at the site (MW-1 through MW-6) were dry or contained little water column and exhibit slow recharge rates Due to these factors, we do not recommend using these wells as primary observation wells for the constant-rate aquifer test We propose to utilize Wells MW-7, MW-8, MW-9 and MW-14 . as primary observation wells The well screening intervals, total completion depths, and radial distances from the extraction well are presented in Table 1 During the pump test, drawdown in the extraction and observation wells will be measured using a datalogger equipped with pressure transducers The pressure transducers are placed near the bottom of each well where they measure the pressure exerted by the overlying water column (head) The pressure transducer and datal6gger measure the head to hundredths of a foot Once the aquifer test has been completed, the data stored in the datalogger is downloaded to a personal computer for analysis We propose to analyze the raw test data using the modified non-equilibnum method (Cooper and Jacob, 1946) In accordance with this method, data plots of drawdown versus time will be prepared on semi-loganthmic graphs and best-fit lines will be used to estimate aquifer transmissivity Because water will be extracted at a constant rate from Well EW-1 and drawdown measurements will be collected from the observation wells during the test, a distance- drawdown graph can also be prepared The distance-drawdown graph will be used to estimate the aquifer transmissivity independently of the those determined by time-drawdown Plots The radius of influence (i a capture zone) will also be estimated using the distance- drawdown graphs QwI081-1 Audit Semces Inc. CMS/Geweke wpl 2