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interbedded silt layers were encountered to a depth of 45 5 feet, the maximum depth explored Groundwater was encountered in the borings at approximately 10 to 15 feet bgs during drilling ' activities The upper water bearing zone is believed to be semi-confined to unconfined Cross- section loctions are shown on Figure 8 Cross sections are shown on Figures 9 and 10 Descriptions of soil types encountered during drilling, and depths of first encountered ' groundwater, are shown on the boring logs contained in Appendix I 5.2 Analytical Results - Soil ' The results of laboratory analyses of the soil samples collected from the bonngs indicate that TPHg and BTEX were detected above method detection limits in soil samples collected from borings SB2 at 20 5 and 25 feet bgs, SB3 at 20 feet bgs, SB4 at 15 and 25 5 bgs, SB6 at 25 feet ' bgs and SB8 at 25 5 bgs Benzene was detected in bonngs SB2 (0 018 ppm and 0 023 ppm), SB4 (0 051 ppm), SB6 (0 026 ppm) and S138 (0 042 ppm) TPHg was detected in bonngs SB2 (1 1 ppm) and SB4 (18 ppm) Petroleum constituents were not detected in any of the samples ' analyzed from borings SBI, SB5 and SB7 Analytical results are summarized in Table 1 and copies of laboratory reports are contained in Appendix II 1 Copies of the laboratory reports containing results of the geophysical parameter analysis of the three soil samples from bonngs SB4 and SB7 are included in Appendix II ' 5_3 Analytical Results - Groundwater The results of laboratory analyses of the groundwater samples collected from the bonngs indicate that petroleum hydrocarbons were not detected in any of the samples above method detection limits Analytical results are presented in Table 2 and copies of laboratory reports are presented in Appendix II 6.0 GROUNDWATER GRADIENT 1 Static groundwater elevations were measured in each monitoring well on March 25, 1997 Groundwater was measured at approximately 5 6 feet above sea level Prior to this investigation, ' static groundwater elevations were measured in each monitoring well on September 30, 1996 where groundwater was measured at approximately 0 5 feet below sea level The rise in groundwater detected in March 1997 is most likely the result of a seasonal trend as a rise in the water table was also observed during the Spring of 1995 and 1996 The groundwater elevations from the March 1997 monitoring event were used to create the groundwater gradient map on Figure 3 The gradient map shows a westerly groundwater flow direction at an average gradient of approximately 0 0009 ft/ft, or approximately 4 7 feet/mile A slight mounding effect is seen in the vicinity of well MW3 Water level measurements indicated groundwater flow direction beneath the site during March 1997 was generally consistent with gradients observed in the past ' Groundwater monitoring data are summarized in Table 3 w 1943261repor1slsumrptdoc 4 1 • SMTH 1