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i <br /> after site remediation. At this time, contamination levels are <br /> moderate and the plume is moderately well delineated. Therefore, we <br /> do not recommend groundwater remediation at this time. Rather, we <br /> recommend that the quarterly groundwater monitoring program be <br /> continued. The next sampling event should be scheduled for December <br /> 1993 . <br /> 5. 4 Residual soil Contamination <br /> I Soil samples from the excavation and the installation of MW-4 <br /> indicate that soil contamination extends off-site to the north and <br /> northwest. The data also indicate that most of the residual soil <br />' contamination exists within the capillary fringe and upper portion <br /> of the phreatic (i . e. saturated) zone. Because subsurface <br /> conditions away from soil samples can vary widely, it is difficult <br /> to estimate the amount and concentration of remaining soil <br /> contamination. Using available data, the volume of remaining <br /> contaminated soil can be approximated by multiplying the distance <br /> between the excavation and MW-4 (85 feet) by the width of the <br /> excavation or contaminated plume (40 feet) by the approximate <br /> thickness of the capillary fringe (3 feet) . This calculation yields <br /> approximately 375 cubic yards of contaminated soil. The average TPH <br /> level of this residual contamination is probably between 100 ppm <br /> and 400 ppm, as indicated from the analysis of the excavation and <br /> monitoring well soil samples. <br /> Excavating the contaminated soil is clearly not a viable option. If <br /> the soil cannot remain In place, then an in-situ (in place) method <br /> of remediation will need to be implemented. <br /> 6. 0 LIMITATIONS <br /> IOur professional services were performed using that degree of care <br /> and skill -ordinarily exercised by environmental consultants <br /> practicing in this or similar localities. The findings were mainly <br /> I based on analytical results provided by an independent laboratory. <br /> No other warranty, expressed or implied, is made as to the <br /> professional recommendations contained in this report. <br /> The opportunity to prepare this report is greatly appreciated. <br /> Please contact our office if you have any questions or comments. <br /> I <br /> 18 <br />