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' 12 December 2006 AGE-NC Project No 01-0827 ' Page 2 of 14 ' In October 1992 UST#2, UST#3 and UST45 were removed from the site, along with the dispenser lines which served the site's dispenser located at the southwestern corner of the building UST#5 was a 500 gallon UST used for the storage of diesel fuel UST#2 was a 1,000 gallon gasoline UST and ' UST#3 was a 500 gallon diesel UST These two USTs serviced the western dispenser on the on the fuel island Contamination was reportedly evident on the southern excavation wall However,the only sample with reported hydrocarbons was collected at the dispenser island (P1) Sample P-1 ' contained at total petroleum hydrocarbons as gasoline (TPH-g), and TPH-diesel (TPH-d) and toluene, ethyl-benzene and xylene at concentrations of 1,600 mg/kg, 4,900 mg/kg, 0 33 mg/kg, 4 9 mg/kg and 56 mg/kg, respectively Analytical results of soil samples are depicted in Table 1 22 SITE ASSESSMENT MILESTONES In December 1988 the assessment of the petroleum hydrocarbons release from the USTs began with the installation of soil borings B I through B3, completed as ground water monitoring wells MW-1 ' through MW-3 Soil samples from boring 131 contained TPH-g at a maximum concentration of 350 mg/kg (B1-25) BTEX was detected in the same sample at concentration of 4 7 mg/kg, 21 mg/kg, 18 mg/kg and 110 mg/kg, respectively Analytical results of soil samples are depicted in ' • Table 1 Monitoring well MW-1 was installed at the western edge of the former UST cluster area,well MW-2 ' was installed 100 feet east of well MW-I and well MW-3 was installed 90 feet south of well MW-1 and the former UST excavation The wells were first sampled on 12 December 1988 ' In May 1990,five additional soil borings,B4 though B8 were established on the site Boring B8 was completed as monitoring well MW-4,at a location 140 feet north of well MW-I and the former UST ' excavation In August and September 1992,five additional soil borings,B9 though B 13,were established on the site Boring B 13 was completed as remediation well RW-1,at a location 20 feet north of well MW-1 and the former UST excavation Boring B 12 was completed as ground water observation well PZ-1 between well RW-1 and the former UST excavation�Additionally, boring B9 was completed as vapor well VW-1, boring B10 was completed as vapor we and boring BI I was completed I as vapor well VW-3 During September 1992 a set of ground water and soil vapor extraction(SVE) remediation feasibility pilot studies were conducted on the site One ground water extraction(GWE) pilot test was conducted at well RW-1 and one SVE pilot test was conducted on wells VW2 and VW-3 ' In September 1993, four additional soil borings, boring B 14 thought B17 were established on the site Boring B 14 was completed as monitoring well MW-5 at a location 100 feet west of well MW-1 Advanced GeoEnnronmental,Inc I