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SECTION 7 <br /> CONCLUSIONS <br />' Review of data associated with the post-excavation sampling activities <br /> indicates that the objectives of the sampling activities have been met as <br /> defined in the workplan Specifically, the data verified the accuracy of <br />' the 1993 excavation confirmation sampling and supported the 1993 <br /> confirmation sampling results that indicated that soils exceeding the <br /> TPH cleanup goal had been excavated Furthermore, the data were <br /> sufficient to verify whether TPH-affected sods were present beneath the <br /> buildings located on site and adjacent to the former UST locations <br /> Petroleum-impacted soils appear to be present beneath the budding at <br /> Former Tank Site #2 to a limited degree, but they do not appear to be <br /> present beneath the building at Former Tank Site #1 <br />' The soil and ground water data support the contention that the <br /> volume of residual TPH-affected sods at both former tank saes is <br /> limited in extent The volume of residual TPH-impacted soils at <br /> iFormer Tank Site #2 appears to be larger than the volume of TPH- <br /> impacted soils at Former Tank Site #1 These residual TPH-soils do not <br /> pose a threat to human health due to direct contact, as they are located <br />' in the subsurface, beyond depths where on-site workers or passersby <br /> would be exposed In the case of Site #2, the TPH-soils are beneath the <br />' floor of the warehouse, effectively precluding direct exposure <br /> Furthermore, the residual TPH does not appear to be negatively <br />' impacting ground water quality except potentially on a localized scale. <br /> As described in Section 4, TPH and BTEX concentrations in ground <br /> water beneath the saes have decreased significantly since inception of <br />' monitoring Recent monitoring results indicate that TPH and BTEX <br /> are only associated with wells in the immediate vicinity of the former <br /> tank locations These results corroborate the contention that the source <br /> of hydrocarbons in ground water was effectively removed from each <br /> site in 1993, even though localized residual pockets of soil with <br /> elevated TPH/BTEX concentrations may remain in subsurface soils. <br />' All portions of Sites #1 and #2 suspected to contain residual TPH-sods <br /> are covered by asphalt pavement at ground surface This surface <br /> covering should inhibit rainfall percolation that could enhance vertical <br /> migration of TPH/BTEX into ground water Migration of TPH/BTEX <br /> into ground water is further inhibited by the presence of the warehouse <br /> over residual TPH-soils at Site #2 <br /> 7-1 <br />