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I 07 March 2 03 • 0 AGE-NC Project No 95-0141 Page 7of10 Hydrological Unit 5 (HU5) extends from 117 feet bsg to total depth,,;nd is composed of silt The interval is characterized by increasing pore pressures, from medium low at approximately 117 feet bsg to high at total depth The hydrological units are depicted in cross sectional views A-A' and B-B' (Figures 3 and 4 g p ( lam' ) 33 LABORATORY RESULTS OF SOIL SAMPLES Only one soil sample(CPTl-1-85)was collected and submitted for analysis during the fourth quarter 2002 TPH-g,toluene,ethylbenzene,and total xylenes were detected In the sample at concentrations I of 16 milligrams/kilogram, 16 micrograms/kilogram(µg/kg), 5 1 µg/kg and 24 gg/kg,respectively, benzene was not detected in the soil sample The laboratory report (MAI Lab ID 0210228-001) and chain-of-custody forms are presented in Appendix G Analytical results of the ground water samples are summanzed In Table 2 3 4 LABORATORY RESULTS OF "GRAB" GROUND WATER SAMPLES A total of two "grab"ground water samples were collected from CPT-01, between 96 and 100 feet bsg and between 113 and 117 feet bsg TPH-g was detected In both samples at concentrations of 13,000 micrograms/liter(µg/1) and 140,000 µg/l, respectively BTEX compounds were detected in I both samples at concentrations as high as 4,600 µg/1 benzene, 16,000 µg/1 toluene, 2,100 Pg/1 ethylbenzene and 11,000 gg/1 total xylenes (CP T-01-113-117) In addition, 1,2-DCA was detected in both samples at concentrations of 8 8 µg/1 and 250 �Lg/1, respectively and EDB was detected in sample CPT-01-113-117 at a concentration of 90 �tg/l No other analytes were detected In the grab ground water samples The laboratory report (MAI Lab IDs 0210228-002 and 0210228.003) and chain-of-custody forms are presented in Appendix G Analytical results of the ground water samples are summarized in Table 2 I 3 5 GROUND WATER ELEVATION AND GRADIENT At the time of the October 2002 monitoring event, depths to ground water ranged from 2103 feet to 22 15 feet below the tops of the well casings (btoc) Ground water elevations at the site ranged I from 13 25 feet below mean sea level (MSL) in well MW-9B to 14 53 feet below MSL in well MW-813 (Table 1) "Shallow" wells MW-3 and MW-5 were drowned, the depth to ground water . was approximately seven feet above the screen interval of these wells Advanced GeoEnvironrnental,Inc