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15 February 1999 AGE-NC Project No 96-0229 - Page 6 of 9 measured on 15 and 19 October 1998, are depicted in Figure 1 l Ground water elevation at the site decreased an average 2 96 feet between May 1998 and the October 1998 ground water monitoring events The general ground water gradient at the site was calculated to be approximately 0 004 ft/ft or approximately 21 feet per mile and directed towards the northeast Ground water elevation measured from MW-IOA (screened 23 to 43 feet) was measured 0 44 feet above ground water elevation measured at MW-IOB (screened 50 to 55 feet) Due to the anomalous measurements, data collected from MW-1 and MW-IOB was not utilized to determine ground water elevations In October 1998, the depths to first encountered ground water in wells MW-3 and MW-4 were 2 05 feet and 3 47 feet, respectively, above the tops of their wells casings, wells MW-1 and MW-IOB were approximately 20 9 feet and 22 47 feet above the tops of their well casings Therefore, the wells are "drowned", and may not yield samples fully representative of ground water conditions near the top of the saturated zone, where fuel hydrocarbons would be expected to have the greatest impact Due to the low gradient at the site, slight variations in ground water measurements or changes of recharge/discharge of the local ground water could greatly modify ground water flow direction 34 ANALYTICAL RESULTS OF SOIL SAMPLES A total of ten soil samples were submitted to a DHS-certified laboratory for analysis of TPH-g, BTE&X, MTBE and fuel oxygenates TPH-g was not detected from any of the samples selected for analysis BTEX constituents were detected in the 35-foot and 40-foot soil samples collected from soil boring MW-7 at concentrations ranging between 0 01 mg/kg (milligrams per kilogram) and 0 052 mg/kg ' The highest concentration of benzene was reported in the 40-foot sample from MW-7 at 0 011 mg/kg ' MTBE was detected at a concentration of 0 0053 mg/kg in the 40-foot soil sample collected from MW-8 None of the fuel oxygenates were detected above laboratory reporting limits The analytical results of selected soil samples are summarized in Table 1 The laboratory reports (Castle Analytical Laboratory Reference No 1798 and McCampbell Analytical Inc Lab I D No 97040 - 46. 97396 - 98) and chain-of-custody forms are included in Appendix D 35 ANALYTICAL RESULTS OF GROUND WATER SAMPLES A total of eleven ground water samples were submitted to a DHS-certified laboratory in October 1998 TPH-g was detected in ground water samples collected from wells MW-I through MW-4, Advanced CeoEmironmental,Inc