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G eolagical7'eclxlcs INC. Soil&Groundwater Investigation Report Page 5 Marci Property Project No. 701.2 July 24,2002 MW-104bk V • Laboratory samples were obtained from 55 an�85 feet bgs. The 55 feet bgs sample contained 1300 mg/kg TPH-D and 801 jig/kg Xylene. The 85 feet bgs sample did not contain contaminant concentrations above the laboratory reporting limits. MW-106 f Laboratory samples were obtained from 85 and 95 feet bgs. Neither sample contained contaminant concentrations above the laboratory reporting limits. �. 5.0 CONCLUSIONS AND RECOMMENDATIONS Based on our interpretation of the data collected over the course of this subsurface investigation, GTI has reached several conclusions. These conclusions are based on the premise that the data considered, although incomplete, are representative of actual site conditions. We acknowledge that there may be undiscovered conditions, which would upon their consideration, change our interpretation and thus our conclusions. Our recommendations are based on our knowledge of site conditions, and on the state and limitations of subsurface investigative technology. 5.1 Conclusions Geological Technics Inc. makes the following conclusions. 1. Geology: 0 The geology of the site consists primarily of alternating layers, lenses and +- interstratified beds of clays, silts and sands. Units containing gravels are less frequent. See Appendix B - Boring Logs and Figures 3 & 5 - Cross-Sections for more information. Figures 3 & 5 provide a geologic interpretation of the units observed in the borehole drill logs. • Figure 3: Geologic Cross-Section A-A' illustrates the subsurface from the southwest to northeast sections of the subject area.,'The interpretation incorporates sub-classes such as gravelly clay and silty clay which are consolidated into the general category of clays. There is little correlation in lithologic units between borings. Boring MW- 3 (logged by Wm. Hunter & Associates) contains significantly more clay than the other boreholes. • Figure 5: Geologic Cross-Section B-B' illustrates the subsurface from the northwest to southeast sections of the subject area. There is little correlation in lithologic units between borings as in Cross-Section A —A'. Boring MW-2 (logged by Wm. Hunter & Associates) contains significantly more clay than the other boreholes. Together with the MW-3 data this suggests that contamination would be less likely to migrate eastward across the site. 2. Contaminant Distribution Figures 4 and 6 illustrate the soil and groundwater contaminant distribution as superimposed on cross sections A - A' and B --- B'.' The groundwater data from the June 7, ` 2002, monitoring event are presented in the diagrams adjacent to the respective well's screened interval.