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i 17 July 2002 . AGE-NC Project No. 97-0327 ' Page 4 of 10 ' 2.5. EQUIPMENT DECONTAMINATION The hollow stern augers and the Geoprobe rods were pressure washed prior to each bore hole advancement. Sampling tools and brass sleeves used for sample collection were thoroughly washed with a solution of Alconox, and were thoroughly rinsed with clean tap water prior to each sampling sequence. Following drilling activities, rinseate generated from decontaminating the equipment was ' placed in properly labeled DOT-approved model 17H 55-gallon drums and was stored on-site in an area lacking public access. 2.6. MONITORING WELL COMPLETION ' Soil boring MW-4 was single-completed as a ground water monitoring well utilizing 2-inch diameter, schedule 40, blank polyvinylchloride (PVC) well casing and perforated, 2-inch diameter PVC well casing (0.020-inch slot). The well was installed by placing the PVC well casing assembly ' through the hollow stem of the augers to the total depth of the boring. The augers were incrementally raised as No. 2112 Lonestar Lapis Luster sand (filter pack) was slowly poured down the annulus ' between the well casing and the inner wall of the hollow stem auger. The filter pack was placed adjacent to the screened casing from the bottom of the boring to a point approximately two feet above the top of the screen; following filter pack placement, a surge block was inserted into the well ' casing and was alternately raised and lowered (surged) repeatedly for approximately 20 minutes. Approximately three feet of bentonite chips (annular seal)were placed above the filter pack and were hydrated with clean tap water. The remaining annular space was backfilled with portland cement ' (grout seal). An as-built monitoring well-construction diagram is included as Figure 5. ' 2,7. QUARTERLY GROUND WATER MONITORING PROCEDURES' On 22 March 2002,ground water monitoring and sampling was performed at the site on wells MW-1 ' through MW-4.Ground water monitoring pr cea es . or the sitelIw� ere performed as outlined in Monitoring Well Installation Work Plan - tem 7999, dated 9-September 1999, prepared by AGE and approved by the EHD by letter dated,-23-September 1999. Af DV i° 3b ��lcrt�l� 2.7.1. Well Monitoring and Evacuation Depths to ground water were measured in each well from the top of the well casing to the nearest ' 0.01-foot utilizing a Solinst water level meter; ground water elevation was calculated by subtracting the measured depth to ground water from the surveyed casing elevation (Table 3). Ground water elevations were plotted and contoured on a scaled site map (Figure 8). ' Advanced GeoEnvironmental,Inc.