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Gen(v rcal°IecFinus enc Page 3 Add,tional Site Charactenzation Monta Brothers Project No 7242 December 19,2000 1 A surface seal was achieved by pumping a neat cement grout via a tremae tube (augmented with <4% bentonite) to the surface The wells were secured with a locking watertight cap ' encased in flush mounted traffic-rated well box The new wells have been scheduled for development and sampling in December, 2000 A monitoring report will be prepared once the data has been received from the laboratory 3.0 RESULTS OF INVESTIGATION The analytical results and field observations are discussed below Tabular summaries of all analytical data are included in Appendix A, and the boring logs are included in Appendix B A site map with soil boring and monitoring well locations is included as Figure 2 3.1 Analytical Results Soil Sample Analysis • In summary, no BTEX compounds, TPH-G or MTBE were detected in soil samples from borings MW-6, MW-7, MW-104, MW-106 and MW-107 ' Table 1 in Appendix A is a full summary of soil analytical data collected at the site 3.2 Geology and Field Observations The following section discusses the subjective field observations and geology documented during this investigation based on the interpretations of the field geologist ' • The geology of this site is dominated by clayey soils The clay is typically tan to brown and contains minor amounts of sand As evidenced during this and past investigation events, the color changes to a gray color once groundwater is encountered Iron oxide staining, CaCO3 nodules or streaks, and black organic material are occasionally present in soil samples No evidence of contamination was noted in the field during the installation of off-site well pair MW-6 and MW-106 • No field evidence of contamination was noted in boring MW-7, but a faint hydrocarbon ' odor was noted in boring MW-107 at the 45 and 50 feet bgs sample locations + A gasoline odor was notable in samples from 55 and 60 feet bgs in boring MW-104 ' See Appendix B, Boring Logs for more information ' 4.0 CONCLUSIONS AND RECOMMENDATIONS These conclusions are based on the data collected over the course of this subsurface investigation and premise that the data we 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