Laserfiche WebLink
09 May 2005 <br /> S AGE-NC Project No 97-0301 <br /> Page 3 of 6 <br /> ' 1,2-Dichloroethane(1,2-DCA),ethylene dibromide(EBD),di-Isopropyl ether(DIPE),ethyl <br /> tert-butyl ether(ETBE),tert-amyl methyl ether(TAME),and tertiary butanol(TBA)by EPA <br /> Method 8260B ' <br /> 1 <br /> 3.0. FINDINGS <br /> Ground water elevation flow direction andg radient were determined from field data collected on 09 <br /> December 2004 The contaminant Impact to ground water was quantified by the ground water <br /> ' samples collected on 10 December 2004 <br /> ' 3 1 GROUND WATER ELEVATION AND GRADIENT <br /> ' The depth to ground water measurements at wells MW-1 through MW-12 varied between 34 75 feet <br /> (MW-913)and 36 85 feet(MW-8C)below the tops of the well casings,ground water elevations were <br /> calculated to be between 22 50 feet (MW-8A) and 23 62 feet (MW-8C) below mean sea level <br /> ,. (MSL) The average ground water elevation at the site on 09 December 2004 was 23 03 feet below <br /> MSL Generally, ground water elevation at the site Increased an average 1 03 feet between the <br /> September 2004 and the December 2004 ground water monitoring events oe <br /> ' Ground water elevation data collected on 09 December 2004 from wells MW-8(A-C),MW-9(A-D), <br /> and MW-12 (A-D) is depicted on cross section D-D' (Figure 3) By determining the difference <br /> between ground water elevations(dh)and dividing by the difference of the screen interval midpoints <br /> (dl), the vertical gradient between adjacent screen Intervals was calculated Generally, moderately <br /> steep to steep downward vertical gradients were observed between the Second, Third, and Fourth <br /> 1 Water Zones,while near neutral vertical gradients were observed between the First Water Zone and <br /> the Second Water Zone in the southern portion of the site (Figure 3) <br /> J <br /> The ground water elevations at wells MW-1 through MW-12 were calculated by subtracting the <br /> measured depth to ground water from the surveyed casing elevation The September 2004 ground <br /> 1 water elevation data collected from wells MW-1 through MW-7 were plotted for the First Water <br /> Zone(Figure 4)as defined in AGE'S CPT Site Investigation-Third Quarter 2001 (dated25 October <br /> 2001) Generally, the net ground water flow direction was toward the east to northeast at an <br /> approximate hydraulic gradient of 0 002 foot/foot(ft/ft) <br /> Advanced GcoEnnronmental,Inc <br /> i <br />