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1 09 May 2003 AGE-NC Project No 96-0232 ' Page 9of16 ' 3 4 FINDINGS Ground water elevation, flow direction and gradient were determined from field data collected on ' 24 March 2003, the contaminant impact to ground water was quantified by laboratory analysis of water samples collected on 24 and 25 March 2003 ' 3 4 1 Ground Water Elevation and Gradient ' The depths to ground water were measured at between 10 26 feet (MW-lOA) and 14 29 feet (MW-9C) below the tops of the well casings on 24 March 2003, ground water elevations were calculated to be between 1 98 feet(MW-I QA)and 2 88 feet(MW-10E)below mean sea level(MSL) ' Ground water elevation at the site generally increased an average 1 68 feet between the December 2002 and the March 2003 ground water monitoring events ' Ground water elevation data collected from wells MW-9 (A, B and C), MW-11 (A, B, C and D), MW-13 (A, B, C and D), MW-16, MW-17 and MW-18 on 24 March 2003 was depicted on cross section C C' (Figure 3), by determining the difference between ground water elevations (dh) and dividing by the difference ofthe screen interval midpoints(dl),the vertical gradient between adjacent screen intervals was calculated Generally, very slight downward vertical gradients were observed between the First Zone, Second Zone, Rocky's Upper Zone, Secondary Zone and Primary Zone screen intervals of all the above wells, although a slight to significant increase in upward vertical gradient was measured between Second Zone and Rocky's Upper Zone in the area of wells MW-17, MW-18 and well MW-11 (Figure 3) The 24 March 2003 ground water elevation data collected from the Flag City Chevron site and the i adjacent Three B's Truck Plaza site were plotted for the informal First Zone, Second Zone, Secondary Aquifer Zone and Primary Aquifer Zone hydrogeologic flow units as defined in AGE's Final Remediation Plan, and are depicted in Figures 4, 5, 6 and 7, respectively 3 4 1 1 First Zone Aquifer Ground water elevation data collected in the First Zone Aquifer(10 to 35 feet bsg) at the Flag City Chevron site was inferred to have a radially inward water flow direction towards a ground water depression in the area of Flag City Chevron wells MW-1, MW-2, MW-4 and MW-5 (Figure 4) Ground water flow direction was inferred to be directed towards the east-northeast at the Three B's Truck Plaza, and towards the north at Rocky's Restaurant The ground water gradients were approximately 0 003 ft/ft or less near the Flag City Chevron, and approximately 0 001 ft/ft or less at the Rocky's Restaurant and the Three B's Truck Plaza sites Advanced GmEnvironnsentai,Inc