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28 November 2005 AGE-NC Project No 96-0232 Page 3 of 8 _ transported to a California DHS-certified laboratory for analysis for O TPH-g and TPH-d by EPA Methods 503013/8015Cm and 3510C/8015C, respectively, G Methyl-tertiary butyl ether (MTBE) by EPA Method 8260B 24 FINDINGS Ground water elevation, flow direction and gradient were determined from field data collected on 26 September 2005, the contaminant impact to ground water was quantified by laboratory analysis of water samples collected between 27 and 28 September 2005 2 4 1 Ground Water Elevation and Gradient The depths to ground water were measured at between 11 84 feet(MW-18)and 16 22 feet(MW-9C) below the tops of the well casings on 26 September 2005, ground water elevations were calculated O to be between 1 11 feet (MW-13B&C) and 2 82 feet (MW-10B) below mean sea level (MSL) The 26 September 2005 ground water elevation data collected from the Flag City Chevron site and the adjacent Three B's Truck Plaza site were plotted for the informal First Zone and Second Zone hydrogeologic units as defined in AGE's Final Remediation Plan,and are depicted in Figures 3 and 4, respectively 2 4 1 1 First Zone Aquifer Ground water elevation data collected in the First Zone Aquifer(15 to 35 feet bsg) at the Flag City Chevron inferred a net ground water flow towards the east-southeast at a hydraulic gradient of 0 001 ft/ft or less The ground water gradient along the western edge of the Three B's Truck Plaza inferred a net ground water flow direction towards the east at a hydraulic gradient of approximately 0 001 ft/ft (Figure 3) 2 4 12 Second Zone A uifer Ground water elevation data collected in the Second Zone Aquifer(40 to 60 feet bsg) inferred a net ground water flow direction at the Flag City Chevron towards the southeast at a hydraulic gradient of 0 003 ft/ft or less The ground water gradient at the Three B's Truck Plaza inferred a net ground l� Advanced GcoEnvironmental,Inc