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8 Site Background Information: Quick N Save #1 Page 4 of 6 per kilogram (mg/kg) at 30 feet, and 2,600 mg/kg at 40 feet. TPH-g was detected in VW-4 at a depth of 25 feet and at a concentration of 1 .5 mg/kg. BTEX compounds were detected in all three soil samples from EW- 1 ; maximum concentrations were detected in the sample collected at 40 feet. ;J Benzene was detected at a maximum concentration of 16 mg/kg; toluene at 66 mg/kg; ethylbenzene at 25 mg/kg; xylene at 128 mg/kg. Benzene was detected in VW-3 at 35 feet at a concentration of 0.03 mg/kg. Ethylbenzene was detected in VW-3 at 25 feet and VW-4 at 25 feet, at concentrations of 0.014 and 0.013 mg/kg, respectively. Xylenes were detected in VW-3 at 25 feet and VW-4 at 25 at concentrations of 0 .028 and 0.024 mg/kg, respectively. MTBE was detected in the sample collected from EW- 1 at 30 feet only, at a concentration of 0.78 mg/kg. MTBE was detected in seven out of the nine samples from VW- 1 through VW-4, at a maximum concentration of 0.31 mg/kg in VW- 1 at 35 feet bsg. 1 ,2-DCA was detected in all three samples from EW4 , at a maximum concentration of 1 .2 mg/kg in the sample from 40 feet. No other constituents of concern were detected from the laboratory analysis . GROUND WATER PUMPING TESTS On 29 August 2005, a variable rate ground water pumping test was conducted. During the test, maximum ground water draw-down during the first stage of the pump test (pump rate of 1 GPM) measured in extraction well EW4 was 23 . 12 feet after approximately 60 minutes of pumping operation; no significant draw-down was recorded in observation well MW4 (53 .5 ft south of EW- 1); MW- 1 through MW-3 showed very slight draw-downs of between 0.03 and 0.08 ft ( 19.5, 26, and 25.5 ft west, north, and east of EW- 1 , respectively). Observed draw downs during the second stage of the pump test (pump rate at 0.75 GPM) were similar: the maximum ground water draw-down measured in well EW- 1 was 19. 53 feet after approximately 125 minutes ofpumping operation (after the restart); no significant draw-down was recorded in observation well MW-4; MW- 1 through MW- 3 showed very slight draw-downs of between 0.02 and 0.04. Due to the results of the 8-hour variable rate pump test, the proposed 24-hour constant rate test was cancelled. Utilizing a semi-logarithmic plot of ground water draw-down vs. observation well distance to pumping well (Jacob straight-line method); a best-fit line was utilized to project a radius of influence for EW- 1 at approximately 29 .8 feet at 1 .0 GPM. Utilizing the Distance-Drawdown Method (Jacob straight-line method) for the first stage of the pump test (1 .0 GPM), a transmissivity was calculated at 10.6 ft /day (equivalent to 79. 1 gallons per day/ft) and a storativity value calculated at 0.0012. For the second stage of the pump test (0.75 GPM), a transmissivity was calculated at 9 .4 fClday (equivalent to 70 gallons per day/ft) and a storativity value calculated at 0.00031 (Appendix J). Based on transmissivity values of 10.6 ftZ/day (first stage) and 9 .4 112/day (second stage) and an aquifer thickness of 20 ft (screen interval at EW- 1), hydraulic conductivity values were calculated at 0 .53 ft/day, or 1 .9 x 104 cm/s (first stage) and 0.47 ft/day, or 1 .7 x 104 cm/s (second stage) . These hydraulic conductivities are consistent with a screened interval located within a silty fine sand. This suggests that although the pilot boring for EW- 1 encountered some coarser grained sand, the fine silty sand encountered between 30 and 55 feet bsg in previous pilot borings for MW- 1 through MW- Advanced GcoEnvironmental, Inc.