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' 03 January 2002 • AGE-NC Project No 97-0301 Page 3 of 5 feet between the June 2001 and the September 2001 ground water monitoring events The ground ' water elevation data obtained during the September 2001 ground water monitoring event is depicted in Figure 3 The inferred ground water flow direction for the area bound by wells MW-i through MW-7 was inferred to be towards the east-northeast at a gradient of 0 004 ft/ft or less, or ' approximately 21 feet per mile (Figure 3) ' 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES A total of seven ground water samples were submitted to a California Department of Health Services ' (DHS)-certified laboratory for analysis TPH-g was detected in water samples collected from wells MW-1 and MW-7 at concentrations of 18,000 micrograms per liter (ug/l) and 45,000 gg/l, respectively, the laboratory reported both samples as having significant unmodified or weakly ' modified gasoline TPH-d was detected in the water samples collected from MW-1, MW-5 and MW-7 at concentrations of 1,900µg11, 88 µg11 and 2,800 gg/1,respectively, the laboratory reported the samples from MW-1 and MW-7 as having significant gasoline range compounds,and the sample ' from MW-5 as having significant diesel range compounds TPH-k was detected in the water samples collected from MW-1, MW-4 and MW-7 at concentrations of 1,900 µg/1, 51 ugll and 5,300µg11, respectively BTEX compounds were detected in ground water samples collected from wells MW-1 and MW-7 at concentrations ranging as high as 6,700 4g11 The greatest benzene concentration was detected in the sample from well MW-7 at 6,700 gg/l 1 MTBE was detected in a water sample collected from well MW-1 at a concentration of 8 8 'Ug/l, TBA was detected in a water sample collected from well MW-I at a concentration of 62 gg/l, 1,2- DCA was detected in water samples collected from wells MW-1 and MW-7 at concentrations of 59 ' and 570 gg/l No other fuel oxygenated compounds were detected during the laboratory analysis Previous and current analytical results of ground water monitoring well samples are summarized in ' Tables 2 and 3 The laboratory reports(McCampbell Analytical Inc Lab I D 79954 through 79960) and chain-of-custody forms are presented in Appendix B ' 4.0. SUMMARY AND CONCLUSIONS ' The implications from the September 2001 ground water monitoring event are as follows • Ground water flow direction for the area bound by wells MW-1 through MW-7 was inferred to be towards the east-northeast at a gradient of 0 004 ft/ft or less (Figure 3), • Due to the low gradient at the site, slight variations in ground water measurements or Advanced GeoEnvironmental,Inc