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• Chevron Products Company 4 Former Chevron Service Station 95775, 301 West Kettleman Lane Lodi California March 30 2000 The well was sampled annually in 1996 and 1997, quarterly during 1998, and monthly in 1999 and 2000 No detectable concentrations of hydrocarbons or fuel oxygenates have been reported in this well (City of Lodi and G -R) AQUIFER TEST SET-UP Step -drawdown and constant -rate aquifer pumping tests were performed using extraction well EX -3 EX -3 (screened from 60 to 80 feet bgs) was pumped using a 3 -inch pump placed at a depth of 78 feet bgs The groundwater effluent was discharged to the existing on-site treatment system An in-line regulator and flow totalizer connected to the discharge line was used to control and monitor the flow rate Pressure transducers with built-in data -loggers (TROLLS) were installed in select wells to electronically monitor water levels during the pumping test Selected wells included monitoring wells MW -1 and MW-14/EX-2 (screened from 55 to 65 feet bgs), MW -5A (screened from 70 to 75 feet bgs), MW -5B (screened from 85 to 90 feet bgs) Background water levels were monitored in wells MW -8A (screened from 55 to 65 feet bgs) and MW -8B (screened from 85 to 90 feet bgs) Locations of selected wells are shown on Figure 2 Additionally, a barometric pressure probe, installed in MW-14/EX-2, was utilized to monitor changes in the barometric pressure during the aquifer pump test The data -loggers were programmed to record data at logarithmic intervals, measuring water levels frequently upon initiation of the pump test and less frequently as the water levels stabilized A baseline set of static water -level measurements were manually collected from wells MW-14/EX-2, EX -3, MW -1, MW -5A, MW -5B, MW -8A, and MW -8B prior to test initiation and prior to test conclusion Periodic manual water levels were also collected from the wells to validate data -logger measurements STEP -DRAWDOWN PUMPING TEST The step -drawdown test was performed at the site on November 17, 2000 The step - drawdown test was performed to assess the sustainable yield of the pumping well for the constant rate aquifer pump test The appropriate pumping rate is that which will affect the largest anticipated zone of influence without pumping the well dry during the test The step - drawdown test was conducted using a variable speed submersible pump installed in well EX - 3 A pressure transducer connected to a single -channel data -logger was also installed in well EX -3 to electronically monitor changes in water levels during the step -drawdown test In addition, a TROLL installed in monitoring well MW -1 was also used to monitor water level fluctuations Prior to test initiation, water levels in wells EX -3 and MW -1 were manually measured The well was pumped for specific periods at different pumping rates (steps) while changes in the water levels were momtored The water levels and corresponding times were recorded during each pumping step to allow for analysis of the drawdown attributed to each I 1Chevron195775Wqutfer test\Revtsed195775Aqutfertestrevtsed doe