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17 July 2002 <br /> . AGE-NC Project No. 97-0327 <br />' Page 6 of 10 <br />' 3.L ,SITE STRATIGRAPHY <br /> A brown to reddish brown, damp to moist, silty sand was encountered at a depth of 15 feet bsg at <br />' MW-4 and from 15 to 35 feet bsg at P-12. A pale gray-brown and reddish brown, damp to moist, <br /> sandy silt with thin, apparently laterally discontinuous sand layers was generally encountered at <br /> depths between 15 and 75 feet bsg at P-10 and P-11,between 20 feet bsg and total depth(70 feet) <br /> ' in MW-4, and between 40 feet and total depth (55 feet) at P-12. Grayish-brown, damp, fine to <br /> medium sand was encountered between 80 and 90 feet bsg at P10 and P-11. Saturated soil was <br /> observed in all soil sample duplicates at approximately 60 feet bsg. <br /> ' Boring logs are included-in Appendix A. General lithology beneath the site is depicted in cross- <br /> sections A-A' and B-B'in Figures 3 and 4,respectively. <br /> 3.2. FIELD EVIDENCE OF HYDROCARBON-IMPACTED SOIL <br /> ' Faint to moderateY <br /> etroleum hydrocarbon odor was encountered between 25 and 50 feet in soil <br /> P <br /> ' samples collected from soil boring P-10,between 25 and 55 feet bsg from boring P-11 and between <br /> 45 and 55 feet bsg from boring P-12. <br /> ' Organic vapor(confirmed with the PID)was noted in the 40-,45- and 70-foot soil sample duplicates <br /> collected from soil boring P-10,in the 25-, 35-, 40-,45- and 50-Foot soil samples duplicates collected <br /> from P-11 and the 45-foot soil sample collected from P-12. <br /> 1 <br /> 3.3. GROUND WATER ELEVATION AND GRADIENT <br /> 1 The depths to ground water in wells MW-1 through MW-4 were measured between 53.71 and <br /> 55.20 feet below the tops of well casings; ground water elevations in wells MW-1 through MW-3 <br /> ' were calculated to be between 28.26 feet (MW-3) and 28.36 feet (MW-1) below mean sea level <br /> (Figure 6). Ground water elevation at the site increased an average 2.25 feet between the December <br /> 2001 and the March 2002 ground water monitoring events. Ground water flow direction for the area <br /> ' bound by wells MW-1 through MW-4 was generally toward the southwest at a gradient of 0.001 ft/ft, <br /> or approximately 5 feet per mile. <br /> 3.4. ANALYTICAL RESULTS OF SOIL SAMPLES <br /> ' A total of twenty-one soil samples were submitted to a DHS-certified laboratory for analysis: <br /> ' Advanced GeoEnvironmental,Inc. <br /> 1 <br />