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11 August 1997 <br /> AGE-NC Project No 95-0173 <br /> Page 4 of 10 <br /> 2 2 3 BORING LOGS <br /> During drilling activities, sample duplicates were described on boring logs using the Unified Soil <br /> Classification System(USCS), and were monitored for the presence of organic vapor using a photo- <br /> ionisation detector(PID Microtip HL-2000, calibrated to isobutylene) Boring logs are summarized <br /> in Appendix A General lithology beneath the site in cross sectional view is depicted on Figure Nos <br /> 3 and 4 - Geological Cross Sections A -A ' and B -B', respectively <br /> I2 2 4 WELL INSTALLATION <br /> Ground water monitoring wells MW-5 through MW-9 and SVE wells VW-1 and VW-2 were <br /> Icompleted by using 2-inch diameter PVC (schedule 40) blank and screened casing As the total depth <br /> of each well was achieved, a FVC well casing was emplaced through the hollow stem of the augers <br /> The augers were incrementally raised as a #8 SRI Supreme Sand (equivalent to #3 Lonestar Lapis <br /> Luster sand)was slowly poured down the annulus between the well casing and the inner wall of the <br /> hollow stem auger The filter pack was placed adjacent to the screened casing (0 020-inch screen <br /> size) from the bottom of the boring to a point approximately 2-feet above the top of the screen <br /> Following placement of the filter pack, a surge block was inserted into the PVC casing and lowered <br /> then raised repeatedly for approximately 10 minutes Thereafter, approximately 3 feet of bentonite <br /> chips was placed above the filter pack and hydrated with clean tap water to serve as the annular seal <br /> between the screened and unscreened intervals The remaining annular space was sealed with Portland <br /> Type H cement As-built well construction diagrams are included as Figure Nos 5 through I I - Well <br /> Construction Diagrams <br /> 2 2 5 SURVEYING <br /> A reference point was marked on the top of each well head, and surveyed to the nearest 0 01-foot <br /> to determine the elevation relative to existing wells The results of the well survey are contained in <br /> Table 4 - Relative Gi ound Watei Elevations <br /> 2 2 6 MONITORING WELL DEVELOPMENT <br /> Monitoring wells MW-5 through MW-9 were developed utilizing a two stage submersible pump <br /> Ground water was purged from each well until the water produced was essentially sediment free <br /> Approximately 20-gallons of ground water were purged from each monitoring well Purged ground <br /> water was containerized in properly labeled D 0 T model 17H 55-gallon drums and stored on-site <br /> • in an area lacking public access <br />