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A P • 15 April 2004 AGE-NC Project No 99-0559 Page 5of13 3 1 INSTALLATION OF GROUND WATER RECOVERY WELLS On On 01 and 02 April 2003, four soil bonngs(EW-1 through EW-4) were advanced using a truck- mounted CME 85-HT drill ng equipped with continuous flight I0-inch augers, the drill ng and two- man crew were provided by Cascade Drilling of Sacramento, California The soil bonngs were advanced to a depth of 80 feet below surface grade (bsg), soil samples were not collected Soil cuttings were stockpiled and rinseate were contamenzed in DOT-approved 55-gallon drums and placed in the southwestern portion of the site The boring locations are depicted in Figure 2 The hollow stem augers were steam-cleaned prior to advancement of each soil pilot boring Following drilling activities, nnseate generated from decontaminating the equipment was placed in properly labeled DOT-approved model 17H 55-gallon drums and placed in the southeast portion of the site 3 1 1 Well Completion . Soil borings EW 1 through EW-4 were single-completed as ground water extraction wells utilizing a schedule 40, 4-inch diameter blank polyvinylchloride(PVC)well casing with a perforated(0 020- inch slot)bottom section The wells were 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 filter pack material consisting of a #3 Monterey Sand 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 settle the filter pack material A nominal three-foot seal of bentonite pellets was placed above the filter pack and allowed to hydrate with clean tap water The remaining annular space was backfilled with portland cement An as-built well-construction diagram is included as Appendix A 3 1 2 Well Development On 27 and 28 May 2003, the extraction wells were developed utilizing a stainless steel hand bailer, a 4-inch diameter PVC hand bailer, and a Waterra lift pump Approximately 55 gallons of ground water were purged from the wells before the ground water produced was almost sediment free Purged ground water was discharged from the wells to a properly labeled DOT-approved model 17H 55-gallon drum and was stored at the site • Advanced GcoEnvironmental,Inc