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LIST Removal Repod 4 The Southland CoToratior4 Store 1!20632 4627 Davmm Dr,Stodaoa,CA December 11 1998 ' 6.0 CONCLUSION On October 22, 1998,three 10,000-galion USTs were removed from the site A total of eight soil t samples and three water samples were submitted for laboratory analysis to characterize soil and groundwater conditions from the tank excavation A total of sic soil samples were collected to characterize the soil overburden generated during removal of the USTs and associated piping On ' October 28, 1998,sic sod samples were taken beneath the former dispenser Island and product lines, and on November 13, 1998,two soil samples were taken beneath the vent lines and submitted for laboratory analysis to characterize sod conditions beneath those locations Analytical results indicated sod hydrocarbon levels ranged up to 2,100 mg/kg TPH-G The highest TPH-G levels were found near the center of the south wall of the UST pit Highest benzene and MTBE levels were 4 3 mg/kg and 26 mg/kg, respectively The highest total lead concentration was detected in sample L-2-30,taken from beneath the UST vent lines, at 13 mg/kg The low to non-detectable benzene concentrations relative to TPH-G concentrations indicate probable continuing natural biodegradation ' Analytical results indicated groundwater hydrocarbon levels ranged up to 62,000 pg/L TPH-G Benzene and MTBE levels taken from the UST pit were 660 pgA_and 24,000 pg/L, respectively The total lead concentration in the water sample taken from the UST pit was 0 02 mgA- ' To define the dissolved hydrocarbon plume an additional downgradient monitoring well will be installed at the site in early 1999 If analytical results from groundwater samples taken from the new well indicate non-detectable concentrations of dissolved hydrocarbons, Fluor Daniel GTI, on behalf of the Southland Corporation,will propose site closure/no further action status at the site based on 1) source removal, USTs and fuel dispenser island have been upgraded in compliance with current UST regulations and no longer represent a continued source of hydrocarbons,2)the excavation and removal of contaminated soil and groundwater beneath and surrounding the USTs and fuel dispensers, ' 3)the low benzene to TPH-G ratio indicating continued natural biodegradation, and 4)the dissolved hydrocarbon plume having been defined based on quarterly groundwater monitoring well concentrations 1 20632udlpt(srni) FLUOR DANIEL GTI ` r ��