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30 April 2005 • AGE-NC Project No 96-0232 Page 2 of 9 21 WELL MONITORING AND PURGE PROCEDURES On 28 March 2005, the depth to ground water was measured at each monitoring well from the top of each well casing to the nearest 0 01-foot utilizing a Solinst water level meter The ground water elevation in each monitoring well was calculated by subtracting the measured depth to ground water from the surveyed casing elevation(Table 2) Ground water elevation and vertical gradient data for wells MW-9,MW-11,MW-13,MW-16,MW-17,MW-18 and Three B's Truck Plaza wells MW-6, MW-9 and MW-10 are depicted in cross section C-C' (Figure 3), ground water elevations were plotted for the informal First Zone, Second Zone, Secondary Aquifer Zone and Primary Aquifer Zone hydrogeologic units as defined in AGE's Final Remediation Plan (Figures 4, 5, 6 and 7, respectively) On 28 and 29 March 2005, approximately 7 to 18%2 gallons of ground water (a minimum of three casing-water volumes per well) were evacuated (purged) from wells MW-1 through MW-7 and MW-16 utilizing disposable polyethylene bailers Temperature,pH and conductivity were measured for stabilization at regular purge-volume intervals from each well using an Oakton water analyzer Field data and logs are provided in Appendix B The purged ground water was transferred to the ground water remediation system holding tank for treatment and disposal • Single-completion monitoring wells MW-14, MW-15, MW-17 and MW-18, dual completion monitoring wells MW-19 and MW-20, and multi-level monitoring wells MW-8 through MW-13 were purged utilizing a Watera-Hydro-Lift lI pump equipped with amechanical arm by lowering and raising a 3/8-inch outer diameter,length-discrete polyethylene hose equipped with a ball-valve water tip through the top chambers into the specific water-charged screened section Approximately 25 to 32 gallons of ground water(a minimum of three casing-water volumes per well)were purged from single-completion monitoring wells MW-14,MW-15,MW-17 and MW-18, approximately 7 to 19 gallons were purged from dual completion wells MW-6B, MW-19 (A-B) and MW-20 (A-B), and approximately 1/3 to 43/4 gallons of groundwater were purged from multi-level monitoring wells MW-8 through MW-13 Temperature,pH and conductivity were measured for stabilization at regular purge-volume intervals from each well using an Oakton water analyzer Field data and logs are provided in Appendix B, purged ground water was transferred to the ground water remediation system holding tank for treatment and disposal 22 GROUND WATER SAMPLING Ground water samples were collected from the purged wells MW-1 through MW-7 and MW-16A utilizing new,2-Inch diameter disposable polyethylene bailers,ground water samples were collected from the purged wells MW-6B, MW-8 through MW-15 and MW-17 through MW-20 utilizing 3/s- . inch diameter polyethylene tubing Ground water samples were transferred into one-liter amber Advanced GeoEnvironmental,Inc