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• 18 February 2003 AGE-NC Project No 96-0229 Page 6 of 9 The ground water elevation data for MW-2 through MW-12 durin; the November 2002 ground water monitoring event is depicted and contoured in Figure 7, elevation data for deep-screened wells MW-1 and MW-l OB were not used to determine gro i ind water gradient because thege clevations may be representative of deeper ground water conditions The general ground water gradient at the site was calculated to be approximately 0 003 ft/ft or less, or approximately 16 feet per mile, and inferred to be flowing towards the northeast 3 4 LABORATORY RESULTS OF GROUND WATER SAMPLES r A total of thirteen ground water samples were submitted to Castle Analytical Laboratory, a DHS- certified laboratory in Atwater, California TPH-g was detected in water samples collected from wells MW-1, MW-2, MW-3, MW-6, MW-7, MW-9 and MW-10A at concentrations between 190 micrograms per liter (µg/I) in well MW-10A and 100,000µg/1 in well MW-2 r • BTEX constituents were detected inround watersamples les collected from wells MW-1, MW-2 g p , MW-3,MW-6,MW-7 and MW-9 at a maximum concentration of 24,000 µg/l (xylene,MW-6), the highest benzene concentration was detected in sample MW-1 at a concentration of 6,500 µg/1 E MTBE was detected by EPA Method 8260 in ground water samples collected from wells MWA, MW-2, MW-3, MW-6, MW-7, MW-9, MW-10A, MW-10B and MW-11 at a maximum concentration of 1,500 µg/1(MW-6), 1,2-DCA was detected in samples collected from wells MW-1 rand MW-IOB at concentrations of 140 µg/1 and 2 µL/l, respectively _ No other constituents of concern were detected above laboratory reporting limits in the analyzed samples P revious a nd c urrent a nalytical r esults o f g round w ater m onitoring w ell s amp les a re summarized in Tables 3 and 4 The laboratory reports (Castle Analytical Laboratory reference no 5269) and chain-of-custody forms are presented in Appendix E f 35 LABORATORY RESULTS OF SOIL SAMPLES CA total of six soil samples were submitted to a DHS-certified laboratory for analysis of TPH-g, BTEX, MTBE ETBE, TAME, DIPS, TBA, 1,2-DCA, EDB and total lead Except for total lead, none of the above mentioned fuel components were detected by laboratory analysts Total lead was I detected in all samples except MW-12-25,at concentrations ranging from 3 8 to 5 8 mg/kg, which are well within the background concentrations range of 14 to 108 mg/kg for California soils The I Advanced GeoEnvzronmental,Inc