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20 September 2004 <br />AGE-NC Project No 97-0311 <br />Page 4 of 6 <br />. STRATIGRAPHY <br />Generally, dry silty sand or poorly graded sand was encountered from surface grade to approximately <br />25 feet bsg. Dry to damp silts and clays with layers of sandy silt were encountered from <br />approximately 25 feet bsg to generally 50 feet bsg. From approximately 50 feet to 65 feet bsg damp <br />to saturated medium-grained well graded sand was encountered which comprised the local aquifer <br />zone and was locally covered by clay and silt layers. Hydrocarbon-like odor were not detected in soil <br />samples collected. <br />3.2. ANALYTICAL RESULTS OF SOIL SAMPLES <br />A total of 17 soil samples were analyzed by CTEL for total petroleum hydrocarbons quantified as <br />gasoline, diesel, stoddard and oil, volatile organic compounds and fuel additives. Six soil samples <br />were analyzed for CAM17 Metals. <br />No VOCs, solvents, fuel additives or components were found at or above laboratory detection limits. <br />The C AM17 Metals were not detected above generalized background values for California, nor were <br />heavy metals detected above the method reporting limits. <br />Analytical results of soil samples are summarized in the laboratory report CTEL Project No. CT214- <br />0408115, with quality assurance and quality control (QA/QC) reports and chain of custody forms <br />included in Appendix E. <br />3.3. GROUND WATER ELEVATION AND GRADIENT <br />The elevation of ground water in each monitoring well at the time of the monitoring event was <br />calculated by subtracting the depth to ground water from the surveyed casing elevation; current <br />ground water elevation results are provided in Table 1. <br />The measured depth to ground water in monitoring wells MW-1 through MW-4 ranged between <br />49.51 and 49.98 feet below the top of casing (btoc). The ground water elevations were calculated to <br />be between 0.39 feet (MW-1) and 0.76 feet (MW-3) below mean sea level (MSL). At the time of the <br />August 2004 monitoring event, the potentiometric surface was inferred to be flowing south in the <br />area bounded by the monitoring wells (Figure 3) at a gradient of approximately 0.0028 ft/ft. <br />Advanced GeoEnvironmental, Inc.