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1 <br />' 30 August 2005 <br /> . AGE-NC Project No 96-0229 <br />' Page 3 of 6 <br />' Ethylene dibromide (EDB), 1,2-dichloroethane (1,2-DCA), tert-butyl alcohol (TBA), di- <br /> isopropyl ether(DIPE), ethyl ter -butyl ether(ETBE),tert-amyl methyl ether(TAME), and <br /> methyl tert-buyl ether(MTBE) by EPA Method 8260B <br />' 3.0. FINDINGS <br /> Ground water monitoring field data was utilized to determine ground water flow direction and <br /> gradient, petroleum hydrocarbon-impact to ground water was quantified by laboratory analysis of <br /> samples <br /> 3 1 GROUND WATER ELEVATION AND GRADIENT <br /> The depth to ground water measurements on 04 April 2005 ranged between 30 65 feet(MW-5)and <br /> 33 56 feet(MW-12) below the tops of the well casings Generally,the average ground water depth <br /> at the site was equal to 32 03 feet, ground water levels generally increased an average of 3 19 feet <br /> 10 <br /> between the December 2004 and the Apn12005 ground water monitoring events <br /> Ground water elevations were calculated by subtracting the measured depth to ground water from <br /> the surveyed casing elevations The ground water elevations averaged 18 98 feet below mean sea <br /> level (MSL) at the site, with a range of between 18 14 feet (MW-13D) and 20 60 feet (MW-12) <br /> below MSL <br /> Ground water elevation data collected from wells MW-1 MW-2 MW-3 MW-13 A-D MW-14 <br /> I (A-D), and MW-16 (A-E) on 07 December 2004 is depicted on cross section B-B' (Figure 3) By <br /> determining the difference between ground water elevations (dh) and dividing by the difference of <br /> the screen interval midpoints (A), the vertical gradient between adjacent screen intervals was <br /> calculated Generally, nearly flat vertical gradients and slightly downward vertical gradients were <br /> observed between the Second Water Zone, Second Confining Unit and Third Water Zone screen <br /> intervals of all the above wells (Figure 3), however, moderate upward vertical gradients were <br /> generally observed in the First Confining Unit <br /> Ground water elevations were plotted on scaled site plans for the informal First Water Zone <br /> (between 15 and 45 feet, Figure 4) and Second Water Zone (between 70 and 95 feet, Figure 5) <br /> 3 1 1 First Water Zone <br /> Ground water elevation data collected in the First Water Zone(15 to 45 feet bsg) at the site inferred <br /> IAdvanced GeoEnvironmental,Inc <br /> I <br />