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I Site Background Information AGE-NC Project No 99-0657 IPage 2 of 3 I hydrocarbons quantified as gasoline (TPH-g), total petroleum hydrocarbons quantified as diesel (TPH-d), volatile aromatics (benzene, toluene, ethyl benzene, and total xylenes BTEX), fuel oxygenating compounds Including methyl tertiary-butyl ether(MTBE) and total lead In accordance with the appropriate EPA Methods On 16 May 1999, the excavation was re-sampled due to inconsistencies between the field observations noted during the tank removal and the analysis results ' TPH-g and the fuel oxygenate MTBE were detected In soil samples collected beneath the former USTs at concentrations as high as 260 milligrams per kilogram(mg/kg)and 46 mg/kg,respectively Low levels of BTEX compounds were also detected In the samples collected beneath the former USTs In addition, TPH-d was present at 48 mg/kg in the sample collected from beneath the former dispenser area and TPH-g,TPH-d,and MTBE were detected In samples collected from the excavated (stockpiled) soil The stockpiled soil was transported off-site with approval from the EHD and ' accepted by Mr Dennis Alexander, a local farmer who intended to use the soil to shore up levees around his farm SITE ASSESSMENT ACTIVITIES 10 On 04 June 1997,RAIZ Environmental,Inc over-excavated the original tank excavation to a depth of 22 feet bsg in the area of the previous soil sample locations Subsequently,three soil samples were I collected at 22 feet bsg or 6 feet below the original samples and analyzed for TPH-g and BTEX with MTBE in accordance with EPA Methods 8015m and 8020,respectively TPH-g and BTEX were not detected In any of the analyzed samples MTBE was detected at 22 feet bsg in all three of the soil Isamples analyzed, at a maximum concentration of 4 0 mg/kg In March 2000, four ground water monitoring wells (MW-1 through MW-4) were installed at the I site by Advanced GeoEnvlronmental, Inc (AGE) A total of 13 soil samples were analyzed for TPH-g, TPH-d, BTEX, and the suite of five fuel additives by EPA Method 8260 Modified TPH-g was detected In soil samples analyzed from borings MW-1 and MW-2 at concentrations as high as I 2,300 mg/kg and TPH-d was detected at concentrations as high as 590 mg/kg BTEX compounds were detected,with the exception of benzene, at concentrations as high as I 1 mg/kg, 8 3 mg/kg,and 50 mg/kg, respectively Petroleum hydrocarbons were not detected In soil samples collected from IMW-3 and MW-4 MTBE was detected in a sample collected from momtonng well MW-2 at a concentration of 0 87 mg/kg(MW2-25)by EPA Method 8260 No other oxygenates were detected In the soil sample analysis On 27 and 28 February and 01 March 2002 three soil boring CPT-1 CPT-2 and CPT-3 were advanced on- and off-sate to total depths of 128 feet bsg utilizing cone penetrometer (CPT) technology Seven hydrologic units(HUs)were Identified Significant concentrations of petroleum • hydrocarbons were detected in the water samples collected from boring CPT-2 from units HU3, Advanced GeoEnvwonmental,Inc I