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I31 August 1999 <br /> • AGE-NC Project No 97-0290 <br /> IPage 2 of b <br /> Due to data collection problems with the datalogger, Initial data from the pump test was not <br /> recorded Therefore, on 19 July 1999 the above procedures were repeated A constant flow was <br /> maintained for approximately 45 minutes to record initial drawdown Field data is included in <br /> Appendix A <br /> I22 PUMP TEST DATA ANALYSIS <br /> The 19 July 1999 pump test contained the initial drawdown data and proved to be the best data for <br /> analysis based on graphing and was therefore used for all calculations outlined For wells VWIC, <br /> MW2, SWI and SW2, the drawdown versus time was graphed on semi-logrithmic paper The <br /> transmissivity and storativlty for each well were determined The radius of influence was then <br /> determined by graphing the drawdown in each well at a specific time versus distance The well <br /> efficiency of VW1C was calculated and the transmissivity of the aquifer determined A porosity of <br /> 35 percent was assumed for the aquifer Methods used for the above described calculations are <br /> described in Appendix B <br /> 10 <br /> 23 MONITORING WELL PURGE PROCEDURES <br /> IOn 21 July 1999, a Solinst «ater level meter was used to measure the depth to ground water in <br /> monitoring wells MWI through MW8, sparging wells SWI and SW2 and vapor well VW1C, <br /> relative to the tops of the well casings The ground water elevations and gradient were determined <br /> from these data (Table 1) <br /> After recording water level measurements, pre-cleaned PVC bailers were used to purge monitoring <br /> wells MW I through MW8 of standing water Approximately 9 gallons of water (minimum of three <br /> well casing volumes) were removed from each purged well <br /> Ground water temperature, pH and conductivity were measured at regular purge-volume Intervals <br /> during purging using an ICM water analyzer Field sheets and data are Included in Appendix C <br /> IPurged water was stored on-site in labeled, 55-gallon DOT-approved drums <br /> 24 COLLECTION OF GROUND WATER SAMPLES <br /> The depth to ground water was measured In each well following purging to measure well recharge <br /> . A minunum of 80% recharge was observed In each well Immediately following purging Water <br /> samples were then collected using new disposable plastic bailers Each water sample was transferred <br /> Iinto 40-m1 VOA vials containing 0 5 ml 18% hydrochloric acid as a sample preservative and Into <br /> 4diairced Gro Em iron mental,Inc <br />