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. 26 December 2001 <br />' AGE-NC Project No 97-0290 <br /> Page 4 of 8 <br />' 2 4 GROUND WATER MONITORING WELL ABANDONMENT <br /> On 23 April 2001 ground water monitoring well MW-1 was pressure grouted and abandon In-place <br />' The well casing was initially pre-flied with a cement grout slurry and pressure was applied the <br /> casing top Additional grout was added into the casing after a few minutes of grout infiltration was <br /> observed and pressure again was applied to aide In grout penetration into the well filter pack <br /> I <br /> 25 SPARGE SYSTEM AND ORC MONITORING <br />' The effect of the IAS system and/or ORC was monitored utilizing a YSI-55 dissolved oxygen meter <br /> on ground water During each monitoring event, the depth to ground water and percentage of <br />' dissolved oxygen were measured for available monitoring wells General system maintenance and <br /> adjustments were performed at this time The sparging flow rate was adjusted to approximately <br />' 4 scfm and to a pressure of 6 psi at each well <br /> l <br /> • 3.0. FINDINGS <br /> Ground water elevation, flow direction and gradient were determined from field data collected on <br /> 23 February 2001, 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 between December 2000 <br /> and 16 April 2001, 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 /> The depths to ground water ranged from 43 09 feet to 45 05 feet below the s tops of the well casings <br /> g <br /> on 23 February 2001 Ground water elevations ranged from 3 78 to 4 34 feet above mean sea level <br /> I (MSL) Ground water data is summarized on Table 1 Ground water elevation decreased an average <br /> 0 07 feet since the previous quarter The ground water flow direction was south with a gradient of <br /> 0 001 ft/ft Ground water elevation contours based upon the data for the monitoring event are <br /> illustrated on Figure 3 <br /> 3 2 ANALYTICAL RESULTS OF WATER SAMPLES <br /> • TPH-g was detected in water samples collected from wells MW-2, MW-4, MW-6 and MW-7 at <br /> concentrations of 10,000 micrograms per liter(1,6g11), 2,200,ug/l, 68 µg/1 and 240 ,ug/l, respectively <br /> Advanced GeoEnviron mental,Inc <br />