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k4..' 08 September 2009 AGE -NC Project No. 03-1055 Page 16 of 19 Based on the hydrocarbon concentration of TPH-g in excavated stockpile soil samples and highest concentration of TPH-g in soil at the base of the excavation, an estimated 13 gallons or 64 kilograms (kg) of gasoline were removed from the site during both the UST removal and soil excavation procedures. The procedures and results of the October 2000 soil excavation are presented in the AGE -prepared report entitled Interim Soil Excavation and Quarterly Report - Fourth Quarter 2000, dated 29 January 2001. October and November 2003 On 20 and 21 October 2003, approximately 300 cubic yards ofpetroleum hydrocarbon -impacted soil was excavated from the southwest portion of the site; on 21 October 2003 a 500 -gallon UST was discovered, on the western excavation wall, and excavation activities were halted. On 10, 11, and 12 November 2003 an additional 370 cubic yards of petroleum hydrocarbon -impacted soil was excavated north of the initial excavation (see Figure 2 for excavation areas). On 13 and 14 November 2003, the excavation was backfilled using 5116 -inch pea gravel to approximately 12 feet bsg. The remaining void was filled using clean overburden to surface grade. Impacted soil removed from the excavations was identified and segregated based on OVM readings and field observations. Excavated soil was stockpiled on-site for transportation and was transported and disposed at Forward Landfill in Manteca, California. On 05 November 2003, AGE personnel collected four soil samples (UST -1 through UST -4) from beneath the floor area of the additional 500 -gallon UST, six stockpile soil samples (SICK -1 through STCK-6), and one grab ground water sample (WS -5) from standing water in the excavation pit (Figure 2). On 12 and 13 November 2003, AGE personnel collected five soil samples (EXC-1 through EXC-5) from the side walls of the excavation and twelve stockpile soil samples (STCK-7 through STCK-12). Petroleum hydrocarbons were reported in one (UST -4) of the four soil samples collected from beneath the 500 -gallon UST; TPH-g and TPH-d were reported at concentrations of 39 mg/kg and 120 mg/kg, respectively; and BTEX and MTBE were reported at concentrations of 0.028 mg/kg benzene, 0.14 mg/kg toluene, 0.030 mg/kg ethylbenzene, 0.23 mg/kg total xylenes, and 0.095 mg/kg MTBE. Lead was reported in all four of the UST samples, with a maximum concentration in UST -4 of 14 mg/kg. No other analytes were reported in the soil samples collected from beneath the 500 -gallon UST. No analytes of concern were reported at or above detection limits in the five soil samples (EXC- l through EXC-5) collected from the side walls of the excavation. TPH-g were reported in four of the seven soil stockpile samples at a maximum concentration of 24 mg/kg (STCK-4); TPH-d were reported in three of the soil stockpile samples at a maximum Advanced GeoEnvironmental, ine.