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GEOMATRIX TPHg, TPHd, BTEX, and PAHs were not detected in groundwater samples from monitoring wells WFSMW-1, MW-3, and MW-4, with the exception of fluorene, which was detected at a concentration equal to the detection limit(Le., 0.1 µg/1) in MW-3. 6.0 CONCLUSIONS Based on the results of this and previous investigations, Geomatrix has developed the following conclusions regarding site conditions. ® The site is underlain rimanl fine • rlai p y by grained deposits (i.e., silts)with interbedded coarse grained deposits (i.e., sands and gravel) that are underlain by a sandy lean clay at a depth of approximately 80 feet bgs. The depth to groundwater as measured in May 2002 is 33 to 35 feet bgs. Based on current data from the existing monitoring wells, groundwater flows to the east. Historical data(i.e., 1998) indicated a more northeasterly component to groundwater flow. A slight sheen was observed in MW-2, and MW-1 contained approximately 0.13- ® inches of separate-phase petroleum. a � • TCE was analyzed in the 5 and 10 feet bgs samples collected from C =1-6 and was not detected. • Petroleum hydrocarbon-affected soil was identified in two areas along the northeast perimeter of the site; (1) within an area adjacent to the existing building and (2) within an area further west that is currently used for automobile parking(Fig- ure 3). The lateral extent of petroleum (i.e.,crude) affected soil has been delineated in these areas as part of previous investigations and by advancing boring GMX-9 ® during this investigation. The vertical extent of petroleum hydrocarbon-affected soil at the site is defined by borings GMX-I B and GMX-8. In GMX-1 B and GMX-8, affected soil was identified in field observations at a depth of approxi- mately 75 to 80 feet bgs; the soil samples collected from the terminus of each boring did not contain significant concentrations of petroleum hydrocarbons. • Groundwater samples collected in cross and downgradient wells MW-3, MW-4, and WFSMW-1 did not contain petroleum hydrocarbons. Samples collected within petroleum hydrocarbon-affected soil (MW-2) contained concentrations of TPHg, TPHd(with and without silica gel preparation procedure),BTEX, and PAHs. These detections may be partly due to the presence of a slight sheen that was noted during sampling activities. Iloakltdcptd2ta\Doc_Safc16000s16447.0011RcponlUS Can SoilGW Rpt.doc 10