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' 3 0 RESULTS OF THE INVESTIGATION 31 Geology and Hydrogeology Soils observed during the drilling consisted of clay, silt and fine sand mixtures to the total drilling depth of approximately 55 feet Sandy soils, present between 30 and 55 feet bgs, appear to be underlain by clay/silt soils Detailed soil descriptions are included on the well logs (Appendix C) During the drilling of MW-7 on February 25, 2005, saturated soil and groundwater were first encountered at approximately 54 feet bgs On March 23, 2005, the static depth to the groundwater table at MW-7 was 46 43 feet bgs As such, groundwater appeared to be present under semi-confined conditions Groundwater recharge was observed to be moderately strong On March 23, 2005, the depth to static groundwater across the site ranged from 46 43 feet bgs in MW-7 to 48 63 feet bgs in MW-1 The corresponding groundwater surface elevation ranged from a high of 28 38 feet below mean sea level (msl) at MW-7 to a low of 29 42 feet below msl at MW- 1 The groundwater elevation at MW-1 does not appear to fit the regional trend, possibly due to the presence of free product Otherwise, the groundwater table surface appears as a plane dipping toward the east-northeast at a gradient of approximately 0 0020 foot/foot A groundwater surface contour map is included as Figure 4 The well construction details and groundwater monitoring data are summarized in Table 2 ' Between December 30, 2004 and March 23, 2005, the groundwater surface rose an average of 1 00 feet, the groundwater gradient increased from 0 0016 to 0 0020 foot/foot, and the groundwater flow direction remained toward the east This is consistent with seasonal and historical groundwater surface data 32 Soil and Groundwater Analytical Results The two soil samples collected from the boring for MW-7 did not contain detectable ' concentrations of any of the gasoline compounds analyzed, However, all 10 of the soil samples collected from the remedial feasibility test well borings contained gasoline compounds In general, the gasoline compounds detected consisted of TPH-as-gasoline, BTEX, and MTBE The soil samples collected at the base of both source area borings contained gasoline compounds These soil sample results are summarized in Table 1 and the laboratory reports are included in ' Appendix E • 11