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f 25 August 1995 AGE-NC Project No 95-0143 Page 4 of 6 4.0. FINDINGS 4 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT The relative elevation of ground water in each well was calculated by subtracting the depth to water from the surveyed relative casing elevation (Table 1) Ground water rose an average of 3 28 feet between December 1994 and May 1995 The approximate gradient was calculated to be 0 0015 ft/ft directed northwest (Figure 3) 4 2 LABORATORY REPORT OF GROUND WATER MONITORING TPH-g was detected in monitoring wells MW-6, MW-7 and MW-9 at concentrations of 3,100 µg/l (parts per billion, ppb), 23,000 ppb and 96,000 ppb, respectively BTE&X were detected in each well at concentrations ranging from 100 to 20,000 ppb The analytical results are summarized on Table 2 The laboratory report and chain-of-custody form are presented in Appendix B 43 STRATIGRAPHY Clayey to sandy silts were encountered from the surface to depths of approximately 20 feet with increasing gram size downward Silty sands were encountered from below the silts to approximately 24 feet Larger grained silty sands were encountered from approximately 24 feet to the bottom of the probings (25 5 feet) Boring logs are included in Appendix C 4 4 GEOPROBE SAMPLE RESULTS 4 4 1 SOIL SAMPLES Eight soil samples were analyzed for TPH-g and BTE&X TPH-g, benzene, ethylbenzene and xylenes were detected in sample GP 18-25 at concentrations of 1 6 mg/kg (parts per million, ppm), 0 17 ppm, 0 028 ppm and 0 35 ppm, respectively Benzene, ethylbenzene and xylenes were detected in sample GP21-25 at concentrations of 0 032 ppm, 0 027 ppm and 0 088 ppm, respectively Petroleum hydrocarbons were not detected in the six other soil samples analyzed Organic vapors were detected with the PID in samples GP18-25, GP20-25 and GP12-25 at concentrations of 15 ppm, 2 ppm and 17 ppm, respectively Slight hydrocarbon odors were detected . in each of these samples No other organic vapors or hydrocarbon odors were detected in any of the remaining soil samples Analytical results are summarized on Table 3 The laboratory report and