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lie 16 January 2003 <br /> AGE-NC Project No. 98-0450 <br />' Page 5 of 8 <br />' 3.1. ANALYTICAL RESULTS OF CONFIRMATION SOIL SAMPLES <br /> Petroleum hydrocarbons were detected only in confirmation soil samples collected from boring CB 1, <br />' in the former UST area. TPH-g was detected in one soil sample(CB1-35) at a concentration of 580 <br /> milligrams per kilogram (mg/kg). TPH-d was detected in three soil samples at a maximum <br /> concentration of 800 mg/kg(CB 1-35). TBA was detected in two soil samples,CBI-25 and CBI-30, <br />' at concentrations of 260 microgram per kilogram (pg/kg) and 590 µg/kg, respectively. <br /> No other target analytes were detected in the samples analyzed.Confirmation soil sample analytical <br />' results are summarized in Table 2.The laboratory report(MAI Lab ID 0210505), quality assurance <br /> and quality control (QA/QC) and chain-of-custody are included in Appendix B. <br />' 3.2. RELATIVE GROUND WATER ELEVATION AND GRADIENT <br /> The depths to ground water from the tops of the monitoring well casings were measured at 49.53 to <br /> 50.60 feet bsg. The ground water elevations ranged from 4.85 feet below mean sea level (MSL) in <br /> well MW-5 to 4.43 feet below MSL in MW-4(Table 1); ground water elevation had increased an <br />' average of 3 feet at the site since the previous quarterly monitoring event. The ground water flow <br /> direction was inferred to be southwest to south-southwest at a hydraulic gradient of approximately <br />' 0.003 ft/ft (Figure 3). <br /> Table 1 lists the screen intervals for monitoring wells BMW-1 through BMW-5 and MW-5 and the <br />' assumed screen intervals for monitoring wells BMW-1 and BMW-2. With the exception of MW-5, <br /> the wells were screened across the ground water table; laboratory analytical results obtained from <br /> these wells should be representative of the dissolved hydrocarbon concentrations in the shallow <br />' ground water. <br />' 3.3. LABORATORY RESULTS OF GROUND WATER SAMPLES <br /> TPH-g and TPH-d were detected in two ground water samples collected at the site,at concentrations <br />' of 1,300 micrograms per liter(µg/1)and 3,500 ptg/l,respectively,in sample MW-4 at the former UST <br /> area and 170µg11 and 130µg11,respectively,in sample MW-5 at the down-gradient edge of the site. <br /> Benzene was not-detected in the samples analyzed; the other BTEX compounds were detected at --- <br /> various concentrations with the highest concentrations'occurring in BMW-4 (17 µg/l of toluene). <br /> MTBE was detected in samples BMW-2 and MW-5 by EPA method 8260 Modified at <br /> concentrations of 5.7 gg/1 and 45 µg/l,respectively. In addition,TBA was detected in sample MW-5 <br />' at a concentration of 11 gg/l. <br /> Advanced GeoEnvironmental,Inc. <br /> 1 <br />