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Site Background Information: Ralph's Square AGE -NC Project No. 02-0918 Page 3 of 4 remaining samples submitted from borings B2 through B4. The highest benzene concentration was detected in soil sample B 1-40 at 6.2 mg/kg. MTBE was detected in fourteen of the soil samples analyzed. MTBE was detected in boring B I soil samples from 40 feet bsg to the total depth of the boring (65 feet bsg), at a maximum concentration of 40 mg/kg (B1-40). MTBE was also detected in boring B2 samples from 30 feet bsg to the total depth of the boring (50 feet bsg) at a maximum concentration of 0.25 mg/kg (B2-40), in boring B3 from 30 and 40 feet bsg at a maximum concentration of 0.96 mg/kg (B3-40) and in boring B4 from 20 to 35 feet bsg and at 50 feet bsg at a maximum concentration of 5.2 mg/kg (B4-35). • TBA was only detected in soil sample 133-30 at a concentration of 0.26 mg/kg. Laboratory results of soil samples are summarized in Tables 1 and 2 of this appendix. Three ground water samples collected during the July 2002 monitoring event and one grab ground water sample collected from boring B 1 on 26 June 2002 were analyzed for TPH-g, BTEX and oxygenated fuel additives: • TPH-g was detected in the ground water samples from B1 and MW -I through MW -3 at concentrations of 32,000 micrograms per liter (µg/1), 600 µg/l, 56,000 µg/1 and 55,000 µg/1, respectively. • BTEX constituents were detected in the samples from BI, MW -2 and MW -3 at maximum concentrations of 24,000 µg/1 benzene, 4,500 µg/1 ethylbenzene and 6,700 gg/l xylenes in sample MW -2 and 3,100 gg/l toluene in sample MW -3. • MTBE was detected in samples B1, MW -1, MW -2 and MW -3 at concentrations of 8,600 µg11, 40 µg11, 100 µg/1 and 4,000 gg/l, respectively. • 1,2 -DCA was detected in the sample from MW -2 at a concentration of 61 µg11. • TBA was detected in the sample from B 1 at a concentration of 170 µg/1. Ground water results from previous investigations and monitoring events to date are summarized in the tables of the attached report. STRATIGRAPHY Silt, sand and clay with a tan, brown or gray color, apparently depending on hydrocarbon -impact, was generally encountered from a depth of approximately 5 feet to 65 feet bsg. Silt was the dominant soil type encountered to total depth in the boreholes. Silty sand was encountered between 10 and 15 Advanced GeoEnvironmenlal, Inc.