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pf v i 20 April 2005 AGE-NC Project No 95-0109 Page 5 of 6 • Ground water on-site and off-site was inferred to be flowing towards the south The ground water gradient ranged from 0 002 ft/ft on-site to 0 004 ft/ft off-site • TPH-g was detected in ground water samples from wells MW-6,MW-8,MW-9 and MW-14 at concentrations as high as 4,400 µg/1 (MW-8) • Benzene was not detected above laboratory reporting limits in the sample collected this quarter • TPH-g and BTEX compounds were not detected for the fifth consecutive quarter in recently Installed monitoring wells MW-20,MW-21 and MW-22 The lateral and vertical extent of petroleum hydrocarbon-impacted ground water has been defined • The fuel additive 1,2-DCA was detected in samples collected from wells MW-4, MW-5, MW-9,MW-14 and MW-16 at concentrations rangingbetween 3 9µgll(MW-9)and 6 8 µg11 (MW-14) 1,2-DCA was not detected in any of the recently installed ground water monitoring wells nor the newer deeply-screened wells The lateral and vertical extent of the 1,2-DCA contamination appears to be defined • Eight of twelve analyzed minerals were detected in the samples collected from wells EW-1 iand MW-14 at concentrations ranging from 0 13 mg/l (manganese) to 74 mg/l (Calcium) Total alkalinity in samples EW-1 and MW-14 ranged from 86 mg/1 and 110 mg/l, TDS ranged from 400 mg/1 to 580 mg/1,conductivity ranged from 603 umho to 874 umho and pH ranged from 6 601 to 6 821 The concentrations of minerals detected were below the State of California's Primary Maximum Contaminant Levels (MCLS) Alkalinity, TDS, Conductivity, and pH were all within recommended levels However, manganese detected in EW-1 and MW-14 at 0 13 mg/1 and 2 6 mg/l are above the secondary MCL(0 05 mg/1) for manganese in drinking water • Barium was detected m the sample from well MW-14 at a concentration of 0 19 mg/1 No other metals, including chromium and chromium VI were detected above reporting limits The detection of barium is below the State of California's MCL (1 0 mg/1) for barium in dnnkmg water Based upon data collected from the site during 2004, AGE finds • TPH-g concentrations have decreased to non detect levels in wells MW-1 and MW-4 and remained relatively stable in the remaining wells • Benzene concentrations have decreased to non-detect levels in the samples collected from wells MW-1,MW-4,MW-5,MW-8,MW-9 and MW-14 Benzene concentrations remained non-detect in the samples from the remaining wells Advanced GeoEnvironmenW,Inc