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<br /> ?y TABLE 1
<br /> UST OVEREXCAVATION:SOIL SAMPLE ANALYSES
<br /> Village West Marina, Stoddou-San Joaquin County
<br /> Results expressed in mg/Kg
<br /> ...... .......... ............ . ......... ..............„.,..,....,..... . ...,..,..,. .,..... ..............
<br /> ....... .......... ........... ........ .. .,...,... . ......,..,..... .,.. .. .,...,..,..., ....,..,..,. . ...,..,..,.,..,..,..,,.., ..,..,... .. .., .,..,,.... .,..,..,...., .,...,..,.,..,..,..,..
<br /> iJFT
<br /> A Metl36d lr>'A ivlethod 6(12 CA LUFT
<br /> 15-t 1187
<br /> = Sample':: bateital . Organic
<br /> Na SamQled Benzene Tbllletle I thylbi nzene Xyleneslead
<br /> N-Bottom 07/20/93 4.3 0.065 0.038 0.14 0.57 ND
<br /> S-Bottom 07/20/93 340 5.8 13 8.9 44 ND
<br /> :a N-Wall 07/20/93 330 0.69 0.44 3.4 15 NA
<br /> . 1
<br /> S-Wall 07/20/93 4.7 0.68 0.016 0.46 1.2 NA
<br /> E-Wall 07/20/93 ND ND ND ND ND NA
<br /> W-Wall 07/20/93 ND ND ND ND ND NA
<br /> Reporting 1 mg/Kg 0.005 mg/Kg 0.05
<br /> Limits mg/Kg
<br /> I; ND Not detected above the reporting limit of the laboratory test.
<br /> NA Not analyzed
<br /> Laboratory analyses by Sequoia Analytical of Concord
<br /> v The excavation was backfilled in May 1994 subsequent to collection of stockpile soil samples
<br /> for single-sample-composite analyses in order to detect residual TPH-g and TRPH-d analytes.
<br /> Favorable results (all analytes were nondetectable) allowed for stockpile backfill were approved
<br /> in a letter dated May 10, 1994 from Specialist Collins to Mr. Dwight Davis of the Pegasus
<br /> Group.
<br /> Hydropuncb7 Sampling - April 8, 1994
<br /> Under the supervision of Specialist Collins, three Hydropunch''''boreholes (HP-1, HP-2, and HP-
<br /> `-- 3 shown on the Site Sketch, Figure 2 and the Ground-Water Gradient Map, Figure 3) were
<br /> drilled near the north, east, and west flanks of the overexcavation. Borehole soil samples were
<br /> c=i logged at five-foot intervals by the W.W. Irwin, Inc. field geologist; the samples were chilled
<br /> and retained for laboratory analyses, but the analyses were not required by the SJCPHS-EHD.
<br /> Ground water.was encountered at an average depth of 23.7 feet below surface grade (bsg).
<br /> t
<br /> When analyzed, the ground-water samples collected from HP-1 and HP-2 revealed BTEX
<br /> analytes in nondetectable or fractional concentrations; the sample from HP-1 exhibited 86 µglk
<br /> of TPH-gasoline. When analyzed, the sample collected from HP-3 exhibited TPH-g at 360
<br /> ltgli, and a benzene concentration of 160 lcgl f, prompting the SJCPHS-EHD to order the
<br /> completion of three monitoring wells for ground-water direction and gradient determination, and
<br /> possible definition of the contaminant migratory path. See Table IA for analytical results.
<br /> W.W.Irwin,rm.
<br /> Project No.33616.06
<br /> October 1995 3
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