|
4
<br /> 1
<br /> . ppb MTBE The highest hydrocarbon concentrations were detected in soil
<br />' and groundwater samples collected from borings B-2, B-3, B-5 and B-7
<br /> near the USTs and dispenser islands
<br />' 2.3 May 1999 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 drilled using mud rotary
<br /> drilling but was abandoned due to poor sample recovery A soil sample
<br />' collected from 14-feet bgs to boring 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 hydrocarbons were detected in the soil sample collected
<br />' from 33-feet bgs in this boring Borings CPT-11 and CPT-12 were drilled
<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 Other compounds detected in
<br /> soil samples from borings B-11 and CPT-11 included up to 0 024 p p m
<br /> tetrachloroethene (PCE), 1 1 ppm isopropyl benzene, 9 9 ppm n-
<br /> propylbenzene, 10 ppm 1 ,3,5-trimethylbenzene, 2 9 ppm t-butylbenzene,
<br /> 32 ppm 1 ,2,4-trimethylbenzene, 0 87 ppm sec-butylbenzene, 0 11 p p m
<br />' naphthalene and 5 7 ppm n-butylbenzene No hydrocarbons were
<br /> detected in soil samples collected from boring CPT-12 The CPT also
<br /> provided valuable information on lxthologic and hydrogeologic conditions
<br />' at depth beneath the site Sediments beneath the site are primarily sand
<br /> and sandy silt of relatively high permeability The only significant low
<br /> permeability materials were clayey silt layers located between 26 and 32-
<br /> feet bgs and 50 and 64-feet bgs (in boring CPT-12 only)
<br /> 2.4 June 1998 UST Removal and Contaminated Sohl Excavation
<br /> In June 1998, Remedy Construction removed two (2) 10,000 gallon diesel
<br /> USTs and four (4) 10,000 gallon gasoline USTs from the site Staining an d
<br /> hydrocarbon odors were present in soil beneath the USTs Up to 1 , 100
<br /> ppm TPH-G, 19,000 ppm TPH-D, 14 ppm benzene, 19 ppm toluene, 11
<br /> Ippm ethyl benzene, 120 ppm total xylenes and 23 ppm MTBE were
<br /> detected in soil samples collected from the UST excavations Up t o
<br /> 24,000 ppb TPH-G, 97,000 ppb TPH-D, 490 ppb benzene, 2,700 p p b
<br /> toluene, 780 ppb ethyl benzene, 5,000 ppb total xylenes and 16,000 p p b
<br /> MTBE were detected in grab groundwater samples collected from the UST
<br /> excavations A total of 15 soil samples were collected along the pipelines
<br /> Frank's One Stop Workplan — September 2003
<br /> -2-
<br />
|