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Geofo rcaf?ec(trlusYltc Page 3 We1FInstallation Report S Cardoza(Super Stop) Project No 662 2 January 19,2000 ' 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 will be developed and sampled during the month of January A monitoring report will be prepared once the data has been received from the laboratory A licensed Iand surveyor will be contracted to survey the top of casing elevations into a known benchmark elevation This data will be used for the calculation of groundwater ' gradient ' 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 monitoring well Iocations is included as Figure 2 3.1 Analytical Results Soil Saml2le Anal,r}sis In summary • Low levels of oluene and xylene were detected in the 30-foot soil sample from MW-1 + Low levels of xylene were detected in the 20-foot soil sample from MW-3 • MW-2 was non-detect for all analytes • Low levels of MTBE were detected in the 20 and 30-foot samples collected from MW-1 + Low levels of MTBE were detected in the 20, 30 and 35-foot samples collected from MW-3 • Low levels of TBA were detected in the 20-foot sample collected from. MW-1 Table 1 in Appendix A is a full summary of all soil analytical data collected at the site 3.2 Geology and Ficld Observations The following section discusses the subjective field observations and geology documented during this investigation based on the interpretations of the field geologist ' • The site exhibits alternating sand/clay geology The sand is typically brown to orangish brown and ranges from very fine to very coarse grained The clay was typically a gray to brown color and was slightly plastic to plastic in nature The soil was moist to very moist ' starting at the first sampling interval of 5 feet bgs • A slight gasoline odor was detected in the 20-foot sample from MW-3 Analytical data confirms the presence of low concentrations of xylene in this sample • Groundwater was encountered during drilling at approximately 25 feet bgs See Appendix B, Boring Logs for more information