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4.0 CONCLUSIONS On the basis of the findings described herein as well as previous site investigations, SEACOR concludes the following: Groundwater Investigation ' Groundwater flow in the water table zone is towards the southeast. Based on a southeasterly flow direction, monitoring well MW-2 is located approximately 60 feet downgradient of the former USTs and monitoring well MW-3 is located approximately 95 feet downgradient and cross gradient from the former USTs. The absence of detectable concentrations of TPHg and BTEX in existing well MW- 1A, located at the former USTs,is consistent with groundwater quality data collected from this well during the previous three events and provides further evidence that dissolved phase petroleum hydrocarbon concentrations in groundwater underlying the former USTs have decreased to non-detectable levels. The absence of detectable concentrations of TPHg and BTEX in newly-installed wells MW-2 and MW-3 provide evidence that a plume of petroleum hydrocarbon-affected groundwater originiating near the former USTs does not exist. Confirmatory Soil Boring Analytical testing results from the confirmatory soil boring show that soil vapor extraction has been very effective in removing volatile adsorbed phase petroleum hydrocarbons from subsurface soils in the vicinity of the former USTs. In all but one soil sample collected from the confirmatory soil boring, TPHg were not detected above a detection limit of 1 ppm. With the exception of trace levels of xylenes reported in two samples, aromatic analytes were not detected. SEACOR believes that the confirmatory soil sampling results provide evidence that the petroleum hydrocarbon-affected soils have been adequately remediated and that the trace concentrations of TPHg (1 ppm) and xylenes (0.007 and 0.1 ppm) remaining in subsurface soils no longer pose a threat to underlying groundwater quality. 1 MARDEE.RPT 54414-003-01 MD04 10 l