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Site Background Information: former Blue Star Gasoline Page 2 of 3 Based on quarterly ground water monitoring events conducted at the site beginning in May 2005, ground water is currently encountered at approximately 60 feet below surface grade(bsg)and flows east-northeast. However, local ground water flow patterns at the site have been somewhat erratic. Ground water is considered to be of beneficial use and is used for domestic, industrial and commercial purposes. UNDERGROUND STORAGE TANK REMOVAL On 06 March 2002, three USTs, two dispenser islands, and associated piping were removed from the site under AGE supervision. Six soil samples were collected beneath the USTs and two laboratory-composited and one discrete soil samples were collected from the excavated soil for laboratory analysis. 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 No. 2 and No. 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 sample 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 excavation because of the proximity to a major roadway. Subsequent analytical results of the discrete soil sample from one stockpile of approximately 25 cubic 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 • On 28 through 30 April 2003,three soil borings(B 1,B2,and B3)were advanced at the site to a depth of approximately 65 feet bsg. 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. Benzene, toluene, ethylbenzene, and xylenes (BTEX) 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 micrograms per liter(µg/1) to 1.8 µg/1. • On 02 and 03 May 2005,three groundwater monitoring wells(MW-1 through MW-3)were Advanced GeoEnvironmental,Inc.