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a°7 [11 n
<br /> AN Ms Lori Duncan
<br /> May 20, 1999
<br /> . Page 4 of 6
<br /> 4.2 Laboratory Analysis
<br /> Soil and groundwater samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg)
<br /> and diesel (TPHd) using EPA method 8015 modified, total recoverable petroleum hydrocarbons
<br /> (TRPH) using EPA method 418 1, benzene, toluene, ethylbenzene and xylenes using EPA method
<br /> 8020, volatile organic constituents (VOCs) and gasoline oxygenate additives using EPA Method
<br /> 8260, and total lead using EPA Method 6010/239 2
<br /> 4.3 Soil Analytical Results
<br /> Soils contaminated with petroleum hydrocarbons and VOCs were encountered in ccenter of the
<br /> former UST excavation(boring SB3)beginning at a depth of approximately 5 feet bgs and persis>rto
<br /> a depth of 31 feet bgs No contaminants were detected in the sample collected from boring SB3 at
<br /> 36 feet bgs Laboratory analyses also confirmed the presence of petroleum hydrocarbons and VOCs
<br /> in samples collected from boring SBI at depths of 16, 21, and 26 feet bgs However, no
<br /> contaminants were detected in the sample collected at 30 feet bgs No contaminants were detected
<br /> in any sample collected from boring SB2
<br /> The sample with the greatest degree of contamination was collected from boring SB3 in the center
<br /> of the former UST excavation at a depth of approximately 21 feet bgs This sample contained
<br /> TPHg, TPHd, and TRPH at 680 ppm, 5,000 ppm, and 79,000 ppm, respectively BTEX, various
<br /> solvent related VOCs, and total lead were also detected in this sample Contaminants generally
<br /> decreased by an order of magnitude in this boring between 21 and 31 feet bgs, and were non-detect
<br /> at 36 feet bgs It should be noted that total lead was detected at hazardous levels in the soil sample
<br /> collected from boring SB3 at a depth of 6 feet bgs Total lead in this sample was 3,500 ppm,
<br /> compared to 110 ppm at a depth of 21 feet bgs, 8 5 ppm at 31 feet bgs, and 9 2 ppm at 36 feet bgs
<br /> TPH& TPHd, and TRPH were detected at 1,800 ppm, 4,600 ppm, and 8,300 ppm, respectively, at a
<br /> depth of 21 feet bgs in boring SBI, located approximately 15 feet northwest of the former UST
<br /> excavation The samples collected from 16 and 26 feet bgs in boring SBI contained very low levels
<br /> of contaminants, and the sample collected form 30 feet bgs was non-detect
<br /> Analytical results of soil samples are summarized in Table 2 Laboratory reports and chain of
<br /> custody documentation are included in Attachment 2
<br /> 4.3 Groundwater Analytical results
<br /> The grab groundwater samples collected from borings SBI and SB3 contained petroleum
<br /> hydrocarbon constituents as well as various solvent related VOCs SBI contained TPHg, TPHd,
<br /> and TRPH at 2,700 parts per billion (ppb), 35,000 ppb, and 140,000 ppb, respectively SB3
<br /> contained TPHg, TPHd, and TRPH at 4,500 ppb, 510,000 ppb, and 16,000,000 ppb, respectively,
<br /> which are levels that are indicative of floating product BTEX and VOCs were also detected at
<br /> various levels Most notably, benzene was detected at 2 3 ppb and 170 ppb in SB 1 and SB3,
<br /> respectively The sample collected from bonnia, SB3 also contained dissolved lead at 96 parts per
<br /> • billion (ppb) VNo groundwater sample was collected from boring SB Analytical results of
<br /> groundzelgabbardlsumrpt doc
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