Laserfiche WebLink
' 15 February 2006 <br /> • AGE-NC Project No 95-0184 <br />' Page 4 of 7 <br /> In 'addition, the ground water sample from well MW-4 was analyzed for total petroleum <br />' hydrocarbons quantified as diesel (TPH-d) in accordance with EPA Method 8015M <br /> 3.0. FINDINGS <br /> Ground water elevation and flow direction were inferred from field data Hydrocarbon impact to <br />' ground water was quantified by laboratory analysis of the ground water samples <br />' 31 STRATIGRAPHY <br />' The subsurface stratigraphy between thirty and sixty feet was composed predominantly of <br /> interbedded fine-grained soil, mainly clay, silty clay,clayey silt and silt Notableyvere clay layers at <br /> 25 to 30 fe et and at 55 feet bsg Sand was encountered between 60 to 65 feet bsg and between 67 to ' <br /> 73 feet bsSilt was observed at 65 feet and in the lower portion of EW-1 between 40 to 50 feet bsg <br /> 1 <br /> 10 <br /> 3 2 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> The elevation of ground water in each well was calculated by subtracting the depth to ground water <br /> from the surveyed casing elevation (Table 1) <br /> Depths to ground water ranged from 35 91 feet to 36 34 feet below the tops of the well casings'The <br /> average ground water elevation at the site was 23 19 feet below mean sea level (MSL), indicating <br /> a decrease of 0 3 feet between the third and fourth quarter 2005 monitoring events The ground water <br /> levels were as high as approximately 19 feet above the screened intervals in wells MW-1 through <br /> MW-4, MW-7, VW-213, and VW-5C <br /> r <br />' The groundwater appeared to flowgenerally southeast across the former northern UST area and east <br /> across the southern UST area,under an average hydraulic gradient of approximately 0 007 foot/foot <br /> in the northern and 0 004 ft/ft in the southern portions of the site (ft/ft, Figure 3) <br /> 33 ANALYTICAL RESULTS OF WATER SAMPLES <br />' TPH-g was detected in all of the sampled monitoring wells at concentrations ranging from 420 <br /> micrograms per liter(µg/1)in MW-7 to 790,000 µg11 in VW-2B TPH-d was detected in the sample <br />' from MW-4 at a concentration of 38,000 µg/1 A map of dissolved TPH-g concentrations are <br /> . illustrated on Figure 4 <br />' Advanced GeoEnvironmental,Inc <br />