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r analyzed for TPHg by EPA Method 8015M; and BTEX, MTBE, TAME, TBA, ETBE, DIPE, 1,2-DCA, and EDB by EPA Method 8260B. r3.0 SUBSURFACE CONDITIONS 3_1 Geology Soil from the borings generally consisted of clays from the surface to approximately 15 feet bgs. rSoil consisting primarily of sands or silty sands was encountered between approximately 15 to 35 feet. Soil encountered between approximately 35 to 60 feet bgs consisted of silts and clays and clayey sand. Soils consisting of poorly graded sands were encountered from 60 feet to ' approximately 70 feet bgs. Soils consisting of clays and clayey sands were encountered from 70 feet to approximately 78 feet bgs. Soil encountered between approximately 78 to 90 feet bgs consisted of sands with a layer of clay from 85-86 feet bgs. Soil boring logs with detailed descriptions of soil types are contained in Appendix A. Cross section locations are shown on Figure 4 and generalized cross-sectional interpretation of subsurface conditions are shown on Figures 5 and 6. 3.2 Hydrogeolozy Water levels were measured in monitoring wells MW1 through MW6, MW8, MW9, MW10, and MW12 on December 22, 2004. Water levels in the shallow zone (MW1, MW2, MW3, MWS, ' MW9, and MW 10) ranged from 5 1.94 to 53.71 feet below the tops of the well casing elevations. Water levels in the intermediate zone wells (MW4, MWS, MW6, and MW12) ranged from 53.13 to 53.46 feet below the tops of well casing elevations. Water level in the deep zone well, MW7, ' was 53.5 3 feet below the top of well casing elevation. The water level data were used to develop groundwater elevation contour maps (Figures 7 and 8). Groundwater flow in the shallow zone was towards the northeast during the monitoring period. The average hydraulic gradient in the ' shallow zone on December 22, 2004, was calculated to be 0.001 ft/ft or approximately 5.2 ftlnule. Groundwater flow in the intermediate zone was towards the southwest. The average hydraulic gradient in the intermediate zone on December 22, 2004, was calculated to be 0.016 ft/ft or approximately 84 ft/mile. A summary of groundwater monitoring data is presented in Table 2. ' 4.0 RESULTS 4.1 Soil Analytical Results Petroleum hydrocarbon constituents were detected in soil samples collected from the boreholes ' of MW5 through MW9 and MW12. BTEX constituents were detected in the soil samples collected from the boreholes of MW5 at 89 feet bgs, MW6 at 89.5 feet bgs, MW7 at 50 and 90 feet bgs, MW8 at 65.5 feet bgs, and MW12 at 70 and 90 feet bgs. TPHg was detected in the soil samples collected from the boreholes of MW7 at 50 feet bgs and MWS at 65.5 feet bgs at saEnviromenta11283491reportslsum.doe 4 ATC Associates Inc. 1