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Ground water samples collected from the three newly installed wells during the June, 1996 quarterly sampling event indicated no detectable levels of gasoline or gasoline constituents in any of these wells Analytical laboratory data obtained from the remaining six wells were consistent with data obtained from previous quarterly sampling events 6.3 Soil Vapor Extraction Test Results The soil vapor extraction test performed on monitoring well MW-1 indicated that there was no influence generated at the closest observation well located 49 feet away This was confirmed by readings collected at observation points 53 feet and 100 feet from MW-1 A ground water mound developed in MW-1 during the vapor extraction test The depth ' to water was measured in the casing immediately after removal of the vacuum hose from the well head The measured depth to water was approximately 6 70 feet from the top of the casing The water level dropped quickly and returned to near its original depth of ' 10 34 feet within two minutes This indicates that a relatively strong vacuum was induced at the well head The readings obtained from the PID while monitoring the effluent air stream indicated that only minor amounts of gasoline were being removed during the test Based upon the type of soil encountered during the installation of soil borings and monitoring wells during this recent, and previous, investigations it is likely that soil vapor extraction would not be a feasible remediation alternative for this site The soil vapor extraction test performed by AGS further confirms this contention 7.0 CONCLUSIONS tBased upon the analytical data obtained to date, the lateral and vertical extent of soil and ground water contamination have been defined The spatial distribution of gasoline contamination in soil and ground water supports the concept of gasoline originating from ' a source near the former UST and flowing down to the water table where the gasoline dissolved in ground water The contaminant plume was then spread laterally in the ' downgradient direction (northwest) Gasoline was deposited on soils in the ground water smear zone as the plume of contaminated ground water was carried downgradient ' The spatial distribution of soil contamination resulting from this process is that of an upper zone of uncontaminated soil underlain be a relatively thin layer of contaminated soil from two to five feet thick i r American Geological Services,Inc CA95DE-029 14