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<br /> 15. 5 foot sample fSee Drill Log) . Field inspection and PID
<br /> ,.j testing did not record the presence of organic vapors or
<br /> visual staining of soils typically associated with waste oil
<br /> contamination in Boring SB2 to a depth of 17.5 feet. Slight
<br /> to strong gasoline hydrocarbon odors were noted in boring
<br /> SB3 to a depth of 31.5 feet, the maximum depth explored.
<br /> PID readings in the 20.5, 25.5 and 30.5 samples were 4751,
<br /> 4122, and 1400 ppm, respectively. The depth to first
<br /> t,N groundwater beneath the site was recorded approximately 32
<br /> feet below grade in boring SBI. ----- '
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<br /> 4.2 Laboratory Analysis - Soil
<br /> The laboratory analysis of samples collected at 20.5, 25.5
<br /> and 30.5 feet in boring SBI did not record the presence of
<br /> BTEX above the 0.02 ppm method detection limit_ The TPH-G
<br /> concentrations in these samples and the TPH-PT concentration
<br /> in the 30.5 foot sample were not detected above the 5.0 ppm
<br /> detection limit (Table 1 ) . Elevated concentrations of BTEX
<br /> and TPH-G were recorded in the 20.5, 25.5 and 30.5 samples
<br /> from boring S� The 30_5 footsa e exhibited the highest
<br /> levels with BTEX and TPH-G concentrations of 215, 967, 279,
<br /> 1358 and 11089 ppm, respectively. The laboratory test
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<br /> results for these samples, including BTEX concentrations,
<br /> are summarized in Table 2. The 11.5 and 16.5 foot samples
<br /> from boring SB2 did not record EPA 8010 constituents,
<br /> including Chloroform and Trichloroethane, above method
<br /> detection limits (Table 3) . Laboratory data sheets, chain
<br /> + of custody forms and laboratory quality control data are-
<br /> presented
<br /> represented in Appendix IV.
<br /> 5.0 CONCLUSIONS
<br /> The result of field inspection and laboratory apalysis of
<br /> # soils collected during tank removal and subsequent borings
<br /> drilled within the former tank pits, indicate hydrocarbon
<br /> contamination has occurred as a result of leakage of
<br /> s gasoline product to the subsurface from 'Tanks A and C. The
<br /> absence of significant contamination in the pit sample from
<br /> Tank B and the non-detectable concentrations of EPA 8010
<br /> constituents (including Chloroform and Trichloroethane) in
<br /> samples collected from sail boring SB2 indicate no
<br /> significant leakage of waste oil. occurred at this location.
<br /> ; . Primary source control has been achieved at the site with
<br /> the removal of the three u/g tanks and associated product
<br /> lines. The only other source for continuing contamination
<br /> are the soils contaminated by the leakage of gasoline
<br /> product from Tanks A and C.
<br /> The elevated concentrations of total petroleum hydrocarbons
<br /> recorded in soils to a depth of 30. 5 feet beneath Tank A
<br /> indicates a significant volume of gasoline has leaked. The
<br /> k highest TPH concentration detected in the 30.5 foot sample,
<br /> S Y
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