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1 <br /> 3.0 SUBSURFACE CONDITIONS <br /> t !. Geology <br /> Soil from the borings generally consisted of silty sand and sandy silt from the surface to 1 I to 15 <br /> feet bgs Soil consisting primarily of sand and gravelly sand was encountered in borings MWI <br /> and MW2 between I 1 to 15 feet and approximately 25 feet, while soil encountered in the same <br /> ' interval in MW3 consisted of silty clay Soil encountered between approximately 25 feet bgs and <br /> 56 to 60 feet bgs in all three borings generally consisted of mixed silts and clays with very little <br /> or no sand The percentage of sand in the soil increased in all three borings between 56 to 60 <br /> ' feet and 65 feet, the maximum depth explored in these borings Soil boring logs with a detailed <br /> description of soil types are contained in Appendix A J <br /> ' 3_2 Hydrogeology <br /> Water level measurements were collected from wells MWI through MW3 on January 15, 2004 <br /> Water levels ranged from 51 73 to 52 89 feet below the tops of the well casing elevations The <br /> water level data were used to develop the groundwater elevation contour map (Figure 3) <br /> M Assuming that horizontal isotropic conditions prevail, groundwater in the uppermost aquifer <br /> beneath the site flowed towards the north-northeast The average hydraulic gradient on January <br /> 15, 2004 was calculated to be 0 002 ft/ft or approximately 11 7 ft/mile A summary of <br />' groundwater monitoring data is presented in Table 3 <br /> 4.0 RESULTS <br />' 4.1 Soil Analytical Results <br /> The soil samples collected from borings MWI, MW2, and MW3 did not contain detectable <br /> concentrations of TPHg, TPHd, BTEX, MTBE, TAME, TBA, ETBE, DIPE, 1,2-DCA, or EDB <br />' The soil sample collected from boring MW3 did not contain a detectable concentration of total <br /> lead <br /> Analytical results of soil samples are summarized in Table 1 Laboratory data sheets and chain- <br /> of-custody documentation are presented in Appendix B <br />' 4_2 Groundwater Analytical Results <br /> None of the groundwater samples collected from wells MW1, MW2, and MW3 contained <br /> detectable concentrations of TPHg, TPHd, BTEX, MTBE, TAME, ETBE, DIPE, TBA, EDB, or <br /> 1,2-DCA <br />' w 1268741reportslsum doc 4 <br />