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� v <br /> A S S O C I A T E S I N C <br /> well of 3 91 between these two monitonng events A review of the sae's <br /> groundwater measurements suggest that the water table reaches it's seasonal <br /> 1 height during the spring months where it was measured at its highest level in <br /> March A companson of analytical data corresponding to season does not show <br /> an overall increase of hydrocarbon concentrations at the site <br /> In addition, the site is capped by concrete and asphalt which covers the <br /> hydrocarbon-affected This will further impede the vertical migration of surface <br /> water through the upper clay strata and thus prevent surface infiltration from <br /> leaching contaminants to groundwater <br />' Criterion 2: Separate phase product has been removed to the extent practical. <br />' Free-product has not been observed at the site <br /> Criterion 3: No existing water supply wells, deep aquifers, surface waters or other <br />' receptors are threatened by pollutants remaining in the aquifer. <br /> The on-site domestic well is the closest groundwater receptor to former USTs <br /> (within approximately 125 feet downgradient of the former USTs) The well's <br /> total completion depth and construction details are unknown However, <br /> groundwater analytical data from a monitoring well (MW3) located between the <br /> former USTs and the domestic well indicates that dissolved petroleum <br /> hydrocarbon, if present, are not migrating toward the domestic well Water <br /> samples collected from the domestic well and subsequently analyzed did not <br />' contain petroleum hydrocarbon constituents above MDLs <br />' Clay underlying the site appears to be a continuous, confining stratum extending <br /> across the study area with a thickness of± 15 feet This would be expected act as <br /> a physical barrier against contaminants migrating vertically from above the <br />' overlying strata <br />' Criterion 4: The total pollutant mass remaining in the groundwater is decreasing at <br /> predicted rates and neither creates, nor threatens to create, a risk to human <br /> health and safety or future beneficial uses of the aquifer. <br /> The initial sampling of the on-site wells indicated that only low levels of petroleum <br /> hydrocarbons were present in well MW i Analytical results of subsequent water <br />' samples collected in March 2000, the most recent sampling event, contained no <br /> concentrations of BTEX, TPHg or fuel oxygenate additives above laboratory <br /> MDLs <br /> w 1148$Sreporls\NFA-Request doc 13 <br />