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GEO MATRIX <br /> turbidity, and temperature. The clarity of the water also was observed. After water-quality <br /> parameters stabilized (e.g., a minimum of three consecutive readings with values within 10 <br /> percent for each parameter), groundwater samples were collected using the new polyethylene <br /> disposable bailer. <br /> The groundwater samples were collected in accordance with Geomatrix protocols and decanted <br /> into acidified VOA vials and 1-liter amber bottles provided by the laboratory. Sample contain- <br /> ers were labeled, sealed in plastic bags, and placed immediately in an ice-cooled chest for sub- <br /> sequent delivery to F&B under Geomatrix chain-of-custody procedures. <br /> Purge water and cleaning rinsate were placed in steel 55-gallon drums, identified with pending <br /> analysis labels, and temporarily stared at the site pending future off-site disposal by <br /> ChevronTexaco. <br /> 4.4 ANALYTICAL METHODS <br /> Soil samples were analyzed for total petroleum hydrocarbons(TPH) quantified as crude oil <br /> (TPHc; C10-C36 carbon range) using EPA Method 8015 Modified; BTEX using EPA Method <br /> 8021B; and polynuclear aromatic hydrocarbons(PAHs) using EPA Method 8270 SIM. <br /> Groundwater samples were analyzed for TPHg(C6 to C12 carbon range) and TPHd (CIO to C24 <br /> carbon range)using EPA Method 8015 Modified;BTEX using EPA Method 8021B; and PAHs <br /> using EPA Method 8270 SIM. TPHd analyses were performed both with and without a silica <br /> gel preparation procedure. <br /> 5.4 RESULTS <br /> The following sections describe the results from this investigation_ The analytical results for <br /> soil samples are summarized in Tables 5 and b. Groundwater analytical results from the <br /> monitoring wells are summarized in Tables 3 and 4, along with the historical results from these <br /> wells. Groundwater level elevation data and separate-phase hydrocarbon thickness are summa- <br /> rized in Table 7. Groundwater analytical results are shown on Figure 3. Soil analytical results <br /> are shown on Figures 4 and 5. Analytical laboratory reports are included in Appendix C. <br /> 5.1 GEOLOGIC AND HYDROGEOLOGIC CONDITIONS <br /> Soil encountered during the May 2002 investigation included deposits of fine grained soil, <br /> including silts with sand and gravel with interbedded coarse grained deposits including silty <br /> sands and sands. Depth to groundwater measured in wells MW-2,MW-3, and MW-4 was <br /> 1:Bloc_SafaX5OpO M11.dQ11}Z np smi and QW Repomdoc 7 <br />