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I 25 October 2001 AGE-NC Project No 97-0301 Page 5 of 7 µg11, and in one P-10 water sample collected from Third Water Zone at a concentration of 23 µg11 The greatest benzene concentration was detected from First Water Zone at P-9 at a concentration of 99µg11 tThe only detection of MTBE was in a P-5 water sample collected from First Water Zone at a concentration of 4 2 µg11 ' 1,2-Dichloroethane (1,2-DCA) was detected in one P-5 water sample collected from First Water Zone at a concentration of 19/.,ig/l, in two P-7 water samples collected from First and Second Water ' Zones at concentrations as high as 590µg11, in three P-8 water samples collected from Second and Third Water Zones at concentrations as high as 3 6 kig11, and in one P-10 water sample collected from Third Water Zone at a concentration of 13 Ag1l No other hydrocarbon fuel constituents or fuel oxygenated compounds were detected by the � Iaboratory analyses The laboratory reports (McCampbell Analytical Inc Lab ID's 73125 through ' 73144 and 73280 through 73290, ) and chain-of-custody forms are presented in Appendices B Analytical results of the ground water samples are summarized in Table 1, analytical results of CPT "grab" ground water samples collected in July 2001 and monitoring well ground water samples collected in June 2001 are depicted in petroleum-impact cross sectional views D-D', E-E'and F-F' (Figures 6, 7 and 8) I 3.0. SUMMARY AND CONCLUSIONS ' The implications of the July 2001 CPT investigation results are as follows ' • AGE interprets the CPT data to identify four potential hydrogeologic units informally identified as"First Water Zone"(located 35 to 55 feet bsg), "Second Water Zone"(located 60 to 80 feet bsg), "Third Water Zone" (located 90 to 100 feet bsg) and "Fourth Water ' Zone"(located 110 to at least 125 feet bsg) It is not known how effectively the intervening fine grained intervals hydrologically separate the informal hydrogeologic units though some contamination has migrated through or around them Geologic cross sections D-D',E-E'and ' F-F' were generated from CPT data collected from P-5, P-6, P-7, P-8, P-9 and P-10 and depict general lithology beneath the site in cross sectional view (Figures 3, 4 and 5, respectively) • Permeable lithology consisting of gravelly, fine to coarse sand was commonly encountered at depths between 55 and 65 feet bsg(First Water Zone and Second Water Zone)and 110 and ' 125 feet bsg(Fourth Water Zone), semi-permeable lithology consisting of silty fine sand was commonly encountered at depths between 90 and 100 feet bsg (Third Water Zone) Conversely, less-permeable fine grained, silty clay and clayey silt was encountered at depths Advanced GeeEnvironmental,Inc I