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i i13 April 2005 . AGE-NC Project No 01-0827 iPage 5 of 7 i3 1 GROUND WATER GRADIENT AND FLOW DIRECTION On 31 March 2005, depths to ground water in monitoring wells MW-1 through MW-6 and vapor i wells VW-2d and VW-5d ranged from 21 10 to 23 00 feet below the tops of the casings (btoc) (Table 1) The ground water elevations and gradient were calculated and determined from depth to groundwater data from monitoring wells MW-1 through MW-5 The first quarter 2005 groundwater elevations at the site ranged from 13 87 feet (MW-5) to 14 92 feet (MW-2) below mean sea level (MSL) The ground water flow direction at the UST release was inferred to be towards the east, at a gradient of approximately 0 0009 foot per foot (ft/ft) on-site (Figure 3), while upgradient of the iUST release at Madison Street, a gradient of 0 01 ft/ft was observed i3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES Based on analysis of the 31 March 2005 ground water samples, TPH-g was detected in the ground iwater samples collected from wells VW-2d and MW-6 at a concentration of 2,700 micrograms per liter (µg/l) and 250 µg/1, respectively BTEX compounds were also detected in the ground water sample collected from well VW-2d at concentrations of 190 µg/1 benzene, 25 µg/l toluene, 24 µg/1 iethylbenzene and 28 6µg11 xylenes Ethylbenzene and xylenes were also detected in the deep ground water sample collected from well MW-6 at concentrations of 19 µg/1 and 16 4 µg/l, respectively iThe fuel additive MTBE was detected only in sample VW-2d at a concentration of 41 µg/1 (Tables 2 and 3) No additional analytes were detected at or above laboratory reporting limits in the samples analyzed The analytical results are summarized in Tables 2 and 3 A copy of the laboratory report (CTEL i Project No CT214-0504012), quality assurance/quality control (QA/QC) reports and chain of custody forms are included in Appendix D GeoTracker confirmation pages of the submitted laboratory electronic deliverable format(EDF) files are included in Appendix E I 3 3 ANALYTICAL RESULTS OF SOIL SAMPLES ' A total of three soil samples were analyzed for TPH-g, BTEX and the fuel additive MTBE iTPH- g was detected in the soil samples collected at 20 and 30 feet bsg at concentrations of 26 milligrams per kilogram(mg/kg)at 20 feet and 8 0 mg/kg at 30 feet bsg Benzene,ethylbenzene and total xylenes were detected in the soil sample collected at 30 feet bsg at concentrations of 0 09 Nmg/kg, 13 mg/kg and 10 9 mg/kg, respectively iAdvanced GeoEnvironmental,Inc i