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I06 November 2002 <br /> • AGE-NC Project No 97-0290 <br /> Page 3 of 6 <br /> I dissolved oxygen concentration in available monitoring wells In addition,the depth to ground water <br /> was measured at the available monitoring wells to check for ground water mounding <br /> 2 4 SOIL-VAPOR SAMPLING AND ANALYSIS <br /> Soil-vapor samples were collected from the carbon-adsorption soil vapor extraction system on <br /> 17 July, 19 August and 26 September 2002 The soil-vapor samples were collected in Tedlar vapor <br /> bags using a vacuum pump attached to the influent and effluent stream The samples were labeled, <br /> placed in a pre-chilled cooler and transported under chain-of-custody to McCampbell Analytical <br /> Laboratories Inc The samples were analyzed for <br /> • TPH-g in accordance with EPA Methods 8015 Modified and <br /> • BTEX and MTBE in accordance with EPA Method 8020 <br /> I3.0. FINDINGS <br /> Ground water elevation, flow direction and gradient were determined from field data collected on <br />' • 26 September 2002, the contaminant impact to ground water was quantified from the ground water <br /> laboratory data <br />' From field and laboratory data collected at the SVE remediation system on 17 July, 19 August and <br /> 26 September 2002, AGE determined the average TPH-g concentration, the average flow rate and <br /> calculated the approximate mass and volume of hydrocarbons removed <br /> 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> I The depths to ground water ed from 47 18 feet to 52 28 feet below the tops of the well casings <br /> p �' ranged <br /> on 26 September 2002 Ground water elevations calculated from the well monitoring data ranged <br />' from 0 02 feet above mean sea level (MSL) to 0 36 feet below MSL The depth to ground water <br /> decreased an average 14 feet since the previous quarter Ground water data is summarized on <br />' Table 1 <br /> The ground water flow direction at the former UST release area was south, with a gradient of <br />' 0 0006 ft/ft Ground water elevation contours based upon the data for the monitoring event are <br /> illustrated on Figure 3 <br />' Advanced GeoEnaironmental,Inc <br />