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GROUNDWATER QUALITY MONITORING WELL COMPLETION <br /> When the desired borehole depth of 25 feet was reached, blank casing, screen, filter pack, and <br /> bentonite seal was installed in the hollow-stem auger string. After installation of construction <br /> materials, the hollow-stem auger string was removed, leaving the completed groundwater <br /> quality monitoring well installation in the borehole. A cement grout slurry was then poured <br /> into place to ground surface. <br /> All monitoring well screen/casing strings were thoroughly steam cleaned prior to insertion in <br /> the borehole. All construction materials (filter pack, bentonite and cement) were stockpiled <br /> away from drilling and sampling activities on polyethylene sheeting and covered to prevent <br /> _ contamination. The groundwater quality monitoring well was completed utilizing rigid <br /> NSF-approved PVC casing and screen. <br /> Materials used for constructing the groundwater quality monitoring well included 2-inch <br /> diameter interior/exterior flush threaded NSF-approved rigid PVC Schedule 40 well casing <br /> and well screen. Well screen perforations were precision machine slotted. Screen slot sizes <br /> were 0.020-inch to maximize development of the monitoring well, expedite purging of the <br /> monitoring well prior to sampling, and lower groundwater entrance velocities thereby <br /> minimizing volatilization and not biasing the representativeness of groundwater quality <br /> samples collected from the groundwater quality monitoring well. A 10-foot well screen with a <br /> 4-inch bottom cap was installed in the groundwater quality monitoring well from a depth of 5 <br /> feet above to 5 feet below the existing potentiometric surface. All screen/casing strings were <br /> threaded together. Filter pack material consisted of clean, rounded, water-worn material and <br /> was installed in the annular space adjacent to the well screen to a distance of 2 feet above the <br /> top of the well screen section. Within the annular space above the filter pack material, a <br /> 2-foot thick hydrated bentonite pellet seal was placed. The remaining portion of the annular <br /> space was sealed with a neat cement slurry to ground surface. To protect the monitoring wells <br /> from accidental damage or tampering, a traffic-rated Christy Box with an internal locking <br /> rlgc l(w2-2) Page 3 <br />