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i I15 January 2001 • AGE-NC Project No 96-0232 Page 4 of 20 311 Logging During drilling activities, soil samples were not collected for laboratory analysis or observation Boring logs documenting the as-built ground water extraction well installations are included as Appendix D I3 12 Equipment Decontamination The hollow stem augers were steam cleaned prior to each bore hole advancement Following drilling, rinseate generated from decontaminating the equipment was placed in properly labeled DOT- approved model 17H 55-gallon drums and was stored in a northeast section at the site in an area Ilacking public access ' 3 2 EXTRACTION WELL COMPLETION '. Soil borings EW-4, EW-5,EW-6,EW-7, EW-8, EW-9 and EW-10 were single-completed as ground water extraction wells utilizing schedule 40, 4-inch diameter blank polyvinylchloride (PVC) well casing and perforated, 4-inch diameter PVC well casing (0 020-inch slot) Each of the above mentioned ground water extraction wells were installed by placing a 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 3 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 to facilitate settling of the filter pack Approximately two feet of bentonite chips (transition seal) ' were placed above the filter pack and hydrated with tap water The remaining annular space was backfilled with portland cement As-built well-construction diagrams are included as Figures 3, 4, 5, 6, 7, 8 and 9, ground water extraction well details are summarized in Table 3 3 3 EXTRACTION WELL DEVELOPMENT ' During installation of each of the above mentioned extraction wells, approximately 55 gallons of ground water were bailed from the bottom of each well utilizing a 4-inch diameter stainless steel ' bailer to supplement well development and surging procedures �l Advanced GeoEnvironmental,Inc i