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1 ' Site Background Information former Blue Star Gasoline Page 2 of 3 tof mixed rock sources ' Based ground water data collected during a recent ground water monitoring event, ground water at the site is located approximately 65 feet below surface grade (bsg), and flows toward the south- southeast 1 UNDERGROUND STORAGE TANK REMOVAL ' On 06 March 2002 three USTs two dispenser pe ser islands, and associated piping were removed from the site under AGE supervision Six soil samples were collected beneath the USTs and three ' laboratory-composite/discrete soil samples were collected from the excavated soil Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d, respectively) were detected at concentrations up to 86 milligrams per kilogram (mg/kg) and 0 015 mg/kg Toluene,ethylbenzene,and xylenes were detected at concentrations as high as 13 mg/kg(xylenes) ' The highest concentrations of contaminants were present in the southern samples from Tanks#2 and #3, this location was the fill area for both USTs ' • Approximately 200 tons of soil were excavated during removal of the USTs Two laboratory- composite and one discrete soil samples were collected from the stockpiled soil prior to placement back into the excavation after completion of the UST removal, the soil was placed back into the t excavation because of the proximity to a mayor roadway Subsequent analytical results of the discrete soil sample from one stockpile of approximately 25 yards of soil detected TPH-g at 13 mg/kg and benzene at 0 023 mg/kg Analytical results of soil samples are summarized in Table ' 1 of this appendix • PREVIOUS SITE ASSESSMENT In April 2003,three soil borings(B1,B2,and B3)were advanced at the site(Figure 2) Each boring ' was advanced to a depth of approximately 65 feet bsg Soil and grab ground water samples were collected from each boring and analyzed TPH-g was detected in soil samples at concentrations as high as 1,800 mg/kg, TPH-d was detected at concentrations as high as 580 mg/kg BTEX ' constituents were detected at concentrations as high as 170 mg/kg Although detected in one sample using EPA Method 8021, methyl tertiary-butyl ether(MTBE) and other fuel oxygenates were not detected in any of the samples selected for analysis using EPA Method 8260 ' TPH-g, BTEX, and MTBE were reported in each of the three grab ground water samples collected from the borings at concentrations ranging from 2 3 pg/l to 180 pg/l Analytical results of soil and ' ground water samples are included in Tables 1 and 2 of this appendix On 02 and 03 May 2005, three ground water monitoring wells (MW-1 through MW-3) were Advanced GeoEnviron mental,Inc