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} go 07 May 2002 AGE-NC Project No. 98-0466 Page 6 of 16 • Lead- <5 to 180 mg/kg; • Zinc - 50 to 2,200 mg/kg; • Arsenic - 6 to 11 mg/kg (teepee area); and • Chromium- 30 to 65 mg/kg (burn pits) Sample 63599, collected at 10 feet bsg in the north bum pit, contained 30 mg/kg nickel, 11,000 mg/kg copper, 1,500 mg/kg lead, 400 mg/kg zinc, and 65 mg/kg chromium. Among the 1992 soil samples analyzed, only the lead concentration in sample 63599 and the arsenic concentrations in the teepee area exceeded the PRGs for industrial soil issued by Region 9 of the US EPA. In addition to metals, sample 63599, collected in the backfill in the northern pit in 1992, contained 6 micrograms per kilogram(gg/kg)dichloromethane(DCMA), 8 µg/kg t 'chloroethene(TCE), and 27 µg/kg tetrachloroethene (PCE). Sample 70858, collected at 5 feet bs in the south bum pit did not contain detectable concentrations ofthese analytes.No other samples ere analyzed for solvents. Three samples (63599, 70858 and 70864-south burn pit, 5 feet bsg) cont rined 15 mg/kg, 26 mg/kg and 18 mg/kg diesel-range hydrocarbons. Five other samples from 5 feet bsg and 15 feet bsg in the two bum pits did not have detectable concentrations of diesel-range hydrocarbons. Following excavation of the bum pits and teepee area, soil samples collected from the excavation walls and floors 1994 by Stockton Service Station Equipment Comp (SSSE) contained lead concentrations ranging from less than 4 mg/kg to 10 mg/kg. Soil samples collected from the teepee area in 1994 contained arsenic concentrations were equal to or less than .55 mg/kg - less than the the mean background concentration in California soils and less than the PRG for industrial soil. Concentrations for the other metal analytes did not exceed the TTLC, S rLC or applicable PRGs. Sampling location and analytical results were included in AGE's Site Environmental History report, dated 04 May 2001. AGE visited the burn pit areas on 15 October 1999 and noted that flie excavated soil is still stockpiled on site east and north of the burn pit area. The north burn pith approximate dimensions of 45 feet x 47 feet x 14 feet depth, with a volume of approximately 1,100 cubic yards. The south bum pit had dimensions of approximately 30 feet x 40 feet x 10 feel deep, with a volume of approximately 450 cubic yards. A drawing of the teepee area shows a ci cular area with a 57-foot diameter that is excavated to a depth of 4.5 feet, for a potential volume of approximately 850 cubic yards. AGE advanced one soil boring (PB9) adjacent to the former teepee structure for collection of soil and grab ground water samples during the November 2001 site assessment. Metals concentrations detected in soil samples from boring PB9 were at or near background levels. No other analytes of Advanced GeoEnvironmental Inc.