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3.0 RESULTS OF THE INVESTIGATION 31 Geology and Hydrogeology ' Soils observed during the drilling of MW-4 consisted of massive intervals of clay, silt an fine sand mixtures to a depth of approximately 70 feet, underlain by a poorly-graded fine sand and silty sand interval approximately 15 feet thick This stratigraphy is relatively consistent with soils observed during previous drilling at the site Detailed sod descriptions are included on the monitoring well ' log for MW-4 (Appendix C) During drilling on November 30, 2001, saturated soil and groundwater were first encountered at approximately 75 5 feet bgs On December 17, 2001, the static depth to the groundwater table at MW-4 was 77 34 feet bgs. As such, groundwater does not appear to be present under confining ' conditions Groundwater recharge was observed to be moderately strong ' On December 17, 2001, the depth to static groundwater across the site ranged from 76 96 feet bgs. in MW-1 to 77 83 feet bgs in MW-3 The corresponding groundwater surface elevation ranged from a high of 23 04 feet (arbitrary datum) at MW-2 to a low of 22 86 feet (arbitrary datum) at MW-1 The resulting groundwater surface appears as an irregular plane dipping to the north- northeast at a gradient of approximately 0 0031 foottfoot A groundwater surface contour map is included as Figure 4 The well construction details, wellhead elevations and groundwater monitoring data are summarized in Table 2 ' 32 Soil and Groundwater Analytical Results The three soil samples collected during the investigation did not contain detectable concentrations of any of the gasoline compounds analyzed These soil sample results are summarized in Table 1 and the laboratory reports are included in Appendix D The groundwater samples collected from MW-4 only contained 0 55 µg11 of xylenes No other gasoline compound was detected in the MW-4 sample The groundwater samples collected from the other three monitoring wells (MW-1, MW-2 and MW-3) and the on-site domestic water well did not contain detectable concentrations of any of the gasoline compounds analyzed These groundwater sample results are summarized in Table 3 and the laboratory reports are also included in Appendix D 1 14