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11 January 2007 AGE-NC Project No. 00-0769 Page 7 of 8 3 . 1 . 1 Well Completion The extractionwells willbe completedwith 4-inch diameter, schedule 40 PVC well casing emplaced through the hollow stem augers. The three shallow wells will utilize twenty-feet of slotted well casing (0.030-inch screen size) from 30 to 50 feet bsg and one deep well will utilize 10 feet of slotted well casing (0 .030-inch screen size) from 110 to 120 feet bsg. Filter pack material composed of #3 Lonestar Lapis Luster sand with a moderate proportion of coarse sand, will be poured down the annulus between the well casing and the inner wall of the hollow stem auger as the augers are slowly raised to emplace the filter pack material between the well screen and the bore hole wall. The filter pack will be placed adjacent to the screen from the bottom of the boring to a point approximately 2 feet above the top of the screen. A nominal three-foot interval ofbentonite chip (annular seal) will be placed above the filter pack. Portland cement will be utilized to grout from the annular seal to surface grade. Ground water extraction well construction diagrams are depicted in Figures 3 and 4. 3 . 1 .2. Well Development Development of the proposed extraction wells will consist of a combination of bailing with a stainless steel bailer to remove the major portion of fine-grained sediment from inside the well, surging to flush out or draw in sediment from the filter pack and additional ground water evacuation (purging) with a submersible pump to finish the removal of fine-grained sediment. Developmental purging activities will be continued until field parameter (pH, electrical conductivity, and temperature) readings inproduced water have stabilized andpurged water is visually sediment-free. 3 .2 . INSTALLATION OF REMEDIATION PIPING NETWORK A network of two-inch diameter, schedule 80 PVC piping will be installed aboveground in light traffic areas and belowground in high traffic areas. The belowground piping will be installed in trenches approximately I1/z-foot bsg deep and 146o wide. The PVC piping will be routed from each ground water extraction well head to a water holding tank; the holding tank will be directly connected to the ground water treatment system. A plan showing the proposed piping system and enclosed unit location are depicted in Figure 2. The location of the ground water pump and treat system is proposed to be near the northeast corner of the site (Figure 2). This proposed location of the pump and treat system will allow the on-site tenant to conduct their day-to-day business without interference from the operation of the remediation system. A concrete containment sump will be installed surrounding the ground water remediation system. The pump and treat system will be secured by a chain-linked, gated enclosure approximately 15 feet wide, 30 feet long and seven feet high. Advanced GeoEnvironmental, Inc.