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<br /> . ppb MTBE The highest hydrocarbon concentrations were detected in soil
<br /> and gioundwater samples collected from borings B-2, B-3, B-5 and B-7
<br /> near the USTs and dispenser islands
<br /> 2. 3 Mav 1998 Site Assessment
<br /> In May 1998, Remedy, Inc drilled three soil borings (B-11, CPT-11, and
<br /> CPT-12) at the site (Figure 2) Boring B-11 was dialled using mud t otary
<br /> drilling but was abandoned due to poor sample recovery A soil sample
<br /> collected from 14-feet bgs in boiing B-11 contained 13 ppm TPH-G, 140
<br /> ppm TPH-D, 0 006 ppm toluene, 0 013 ppm ethyl benzene and 0 084 p p m
<br /> total xylenes No hydiocarbom, weie detected in the soil sample collected
<br /> liom 33-feet bas in this boiing Borings CPT-11 and CPT-12 were dolled
<br /> using cone penetrometer testing (CPT) The soil sample collected from
<br /> 13-feet bgs in boring CPT-11 contained 550 ppm TPH-G, 500 ppm TPH-D,
<br /> 0 75 ppm toluene, 3 6 ppm ethyl benzene and 42 ppm total xylenes The
<br /> soil sample collected from 75-feet bgs in boring CPT-11 contained 15 p p m
<br /> TPH-G, 10 ppm TPH-D, 0 036 ppm toluene, 0 11 ppm ethyl benzene, 0 9 6
<br /> ppm total xylenes and 0 093 ppm MTBE Othei compounds detected in
<br /> Soil samples fi om boi Ings B-11 and CPT-11 included up to 0 024 p p in
<br /> tetiachloioethene (PCE), I 1 ppm isopropyl benzene, 9 9 ppm n-
<br /> propylbenzene, 10 ppm 1,3,5-trimethylbenzene, 29 ppm t-butylbenzene,
<br /> 32 ppm 1 ,2,4-trimethylbenzene, 0 87 ppm sec-butylbenzene, 0 11 ppm
<br /> naphthalene and 5 7 ppm n-butylbenzene No hydrocarbons were
<br /> detected in any of the soil samples collected from boring CPT-12 The CPT
<br /> also provided valuable infoimation on lithologic and hydrogeologic
<br /> conditions at depth beneath the Site Sediments beneath the site are
<br /> primarily sand and sandy silt of relatively high permeability The only
<br /> significant low permeability materials were clayey silt layers located
<br /> between 26 and 32-feet bgs and 50 and 64-feet bgs (in boring CPT-12
<br /> only) Neither of these layers should be considered a competent aquitard
<br /> 2 -4 June 1998 UST Removal and Contaminated Soil Fx avatiQn
<br /> In June 1998, Remedy Construction removed two (2) 10,000 gallon diesel
<br /> USTs and four (4) 10,000 gallon gasoline USTs Staining and hydrocarbon
<br /> odors were present in soil beneath the USTs Up to 1,100 ppm TPH-G,
<br /> 19,000 ppm TPH-D, 14 ppm benzene, 19 ppm toluene, 11 ppm ethyl
<br /> benzene, 120 ppm total xylenes and 23 ppm MTBE were detected in soil
<br /> samples collected from the UST excavations Up to 24,000 ppb TPH-G,
<br /> 97,000 ppb TPH-D, 490 ppb benzene, 2,700 ppb toluene, 780 ppb ethyl
<br /> benzene, 5,000 ppb total xylenes and 16,000 ppb MTBE were detected in
<br /> grab groundwater samples collected from the UST excavations A total o f
<br /> Frank's One Stop Workplan — September 2000
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