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GEOMATRIX 2.2 PREVIOUS SITE INVESTIGATIONS Soil and groundwater investigations have been conducted at the site since 1995. During this period, multiple soil borings were advanced and four groundwater monitoring wells (MW-1, MW-2, MW-3, and MW-4)were installed at the site to depths of approximately 50 feet below ground surface (bgs). Results of these investigations indicated the presence of petroleum hydrocarbons in soil within two areas along the northeastern site boundary. Additionally, volatile organic compounds (VOCs)trichloroethylene (TCE), and 1,1,1-trichloroethane (TCA) were detected in site soil in the vicinity of a former drain pipe location at the northeastern side of the building. Petroleum hydrocarbons and cis-1,2-dichloroethene (cis-1,2-DCE)were also detected in groundwater. The presence of chlorinated volatile organic compounds, including TCE, TCA, and cis-1,2-DCE, in soil and groundwater are likely due to former can manufac- turing at the site and are not associated with the OVP. A summary of pertinent results of these investigations is provided below. Soil and groundwater sampling locations are shown on Fig- ure 3. Historical soil and groundwater analytical results are presented in Tables 1 and 2, respectively. 2.2.1 Soil Conditions Petroleum hydrocarbon-affected soil has been identified in two areas along the northern perimeter of the site; (1)within the eastern area of the site adjacent to the existing building and (2) further west in an area currently used for automobile parking (Figure 3). The estimated lateral extent of petroleum hydrocarbon(i.e., crude) affected soil at the site is shown on Figure 3. The vertical extent of petroleum hydrocarbon-affected soil at the site is estimated to a depth of approximately 75 to 80 feet below ground surface (bgs). The highest concentration of TPHc measured in soil at the site was 10,000 milligrams per kilogram(mg/kg) collected from 37 feet bgs from boring GMX-3 in 1999 (Geomatrix, 2000). The highest concentration of benzene measured in soil at the site was 1.0 mg/kg collected from 25 feet bgs from boring B7/MW-2 in 1998 (Radian, ? ). Historical sampling results indicated that TCE was identified in shallow soil within a limited area directly adjacent to the building, in the area of GMX-1. Multiple soil borings have been completed at the site since 1995 to investigate the extent and magnitude of TCE-impacted soil (ERM, 1995a and 1995b: GTI, 1996; WHF 1996b). The highest concentration of WE meas- ured at the site was 9.5 mg/kg in a soil sample collected from boring S-6 in 1995 (ERM, 1995a). The lateral extent of TCE in soil has been defined. TCE has not been detected in soil samples collected at depths greater than 10 feet bgs at the site with the exception of one sample I:\Doc_Safe\6000s\6447.001\OffSite Rpt\US Can SoilGW Rpt 2003.doc 3