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Petroleum-impacted sods appear to be present beneath the budding at <br /> Former Tank Site #2 in a 5-foot thick interval immediately adjacent to <br /> the former tank location Analytical results indicate that hydrocarbon <br /> constituents do not appear to be present beneath the excavation backfill <br /> and that the 1993 excavation effectively remediated the majority of <br /> hydrocarbon-soil outside the building footprint As at Site #1, <br /> TPH/BTEX concentrations have decreased steadily since initiation of <br /> monitoring and do not show evidence of significant impact to ground <br /> water from the presence of residual hydrocarbons beneath the building <br /> Based upon the results of the post-excavation sampling, the residual <br /> 1 hydrocarbon-sods do not appear to pose a threat to human health due <br /> to direct contact, as they are located in the subsurface, beyond depths <br /> where on-site workers or passersby would be exposed In the case of <br /> t Site #2, the hydrocarbon-soils are beneath the foundation of the <br /> warehouse, effectively precluding direct exposure Ground water <br /> monitoring results corroborate the contention that the source of <br /> hydrocarbons in ground water was effectively removed from each site <br /> in 1993, even though localized residual pockets of soil with elevated <br /> TPH/BTEX concentrations may remain in subsurface soils <br />' Furthermore, the presence of overlying asphalt and building structures <br /> mitigate the potential for downward migration of hydrocarbon <br /> constituents into ground water due to infiltration of surface water <br /> Because the localized hydrocarbon occurrences do not appear to pose a <br /> risk to human health and the environment under current site <br /> conditions, no further action appears warranted to address the residual <br /> hydrocarbon-affected soils <br /> 1 <br /> ' viii <br />