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Soil and Groundwater Investigation Quik Stop No 121 Page 7 samples collected for laboratory analysis, with the exception of 0 005 mg/kg toluene at a depth of 28 feet in sample GP-5-28 This concentration is at the detection limit of the laboratory equipment s and is the only soil sample reported by the laboratory to contain petroleum hydrocarbon contamination Only 1 of the 5 groundwater samples was reported to have petroleum hydrocarbon contamination Boring GP-1 was "direct pushed"through the former fuel tank areas on the north side of the site to determine the vertical extent of soil contamination discovered during the March 1998 tank removal and to determine whether groundwater continued to be impacted in this area of the site As previously indicated, no soil contamination was detected However, groundwater contamination as high as 800 ug/l TPHG, 8 ug/1 benzene and 73 ug/l MTBE, along with detectable concentrations of toluene, ethylbenzene and total xylenes,were reported It should be noted that no petroleum odors were detected at this location during the collection of soil and groundwater samples CONCLUSION AND RECOMMENDATIONS Laboratory analyses of the soil and groundwater samples collected from the site during this investigation revealed only one (GP-1) area on the north side of the site to contain petroleum hydrocarbon contamination in the grab groundwater sample This area was report to contain the highest level of soil contamination during the fuel tank removal in March 1998 Based on the data gathered during this Soil and Groundwater Investigation, the soil contamination reported in sample S-5 collected in March 1998 appears to have substantially dissipated Low to moderate levels of petroleum hydrocarbons exist in this area of the site, as confirmed by groundwater sample GP-1W This area of groundwater contamination appears to be localized, since other groundwater samples collected from areas to the east, south and west of the former tank excavation were reported to be free of petroleum hydrocarbon contamination The extent of the groundwater contamination to the north of GP-1 is currently not known However, it is unlikely tha any contamination that currently exists at the site would impact any of the 4 wells located within th 2,000-foot radius of the site CCT recommends the following course of action for the site A) Three groundwater monitoring wells should be installed at the site to determine the groundwater flow direction at the site, B) Quarterly groundwater monitoring should be initiated after the installation of the wells to monitor groundwater quality for a minimum of one year At the conclusion of that time, the site should be reviewed to determine whether additional investigative work is warranted or whether the site should be reviewed for case closure