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Analysis of the groundwater samples was performed by Amencan Analytics In accordance with state guidelines and EPA protocol The groundwater samples were analyzed for TPK BTEX and MTBE using EPA Methods 8015M (modified for gasoline) and 8020, respectively Any groundwater samples detecting MTBE were confirmed using EPA Method 8260 4.0 FINDINGS ' 4.1 Site Lithology and Hydrogeology Subsurface investigations conducted by Park and others encountered interbedded sediments ' consisting of dark brown, moist, poorly sorted, fine to medium grained, silty sands and sands to the maximum depths Investigated of approximately 73 feet bgs Static groundwater Ievels were measured in each groundwater monitoring well on March 30, 1999 Depth to groundwater at the Site ranged from 30 0 to 31 83 feet bgs Groundwater data obtained for the Site and calculated elevations, are presented in Table 3 Groundwater elevations calculated ' from the March 30, 1999 groundwater measurements, Indicated a direction of subsurface flow to the southeast and southwest at an approximate hydraulic gradient of 0 0025 foot per foot ' 4.2 Results of Laboratory Analyses of Soil Samples Soil samples submitted for laboratory analysis were obtained during the dnlling operations conducted on March 31, 1999 Results of laboratory analyses of soil samples for TPHg using EPA Method 8015 indicated the presence of gasoline-range hydrocarbons at concentrations ranging from 14 to 6,400 mg/kg in MW-12 The highest concentration of TPHg in soil was observed in the 50 foot bgs ' sample Aromatic volatile compounds were detected in the soil samples at concentrations ranging from 0 26 to 100 mg/kg for benzene, 0 22 to 520 mg/kg for toluene, 0 014 to 170 mg/kg for ethylbenzene, 0 079 to 840 mg/kg for total xylenes, and ND to 35 mg/kg for MTBE The presence of MTBE in soil samples was confirmed at concentrations ranging from ND to 1 1 mg/kg (EPA 8260) The highest concentration of aromatic volatiles in soil samples were detected in the 50 foot bgs sample ' Analytical results for soil samples from the recent additional sampling event are summarized in Table 2 Isoconcentration contours for TPH, benzene, and MTBE in soli are Included as Figures 7 through 12 Laboratory reports and chain-of-custody forms are presented in Appendix B ' 4.3 Results of Laboratory Analyses of Groundwater Samples ' Presented in the following are the results of laboratory analysis associated with the groundwater samples collected at the extraction well and the observation wells A.1152SJI ASA 10