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i <br /> 4 <br /> i <br /> a MW-1 is screened between 6-feet bgs and 18-feet bgs. Monitoring wells <br /> .yY <br /> MW-2 and MW-3 are screened between 4.5-feet bgs and 16.5-feet bgs. <br /> Monitoring wells MW-4 and MW-5 are screened between 4-feet bgs and <br /> 16.5-feet bgs. In each monitoring well, Lonestar #2112 Monterey sand <br /> occupies the annular space between the borehole and the casing from t h e <br /> bottom of the boring to -approximately 1-foot above the screen. A 1 -foo <br /> t <br /> thick hydrated bentonite layer separates the sand from the overlying <br /> cement surface seal. The cement surface seal in these shallow wells was <br /> placed by gravity free-fall. <br /> The wellheads of all five wells are secured with locking wellplugs beneath <br /> i at-grade traffic-rated vaults. <br /> 9.2 onitoring Well evelopment <br /> I• f <br /> I <br /> i Monitoring wells MW-1 through MW-5 were developed on October 9, <br /> 2000, using surge block agitation and submersible pump evacuation. In k <br /> total, at least ten times the volume of the well casing in was removed <br /> during the development process. Upon completion of the well <br /> development, the water produced in all five wells was clear. <br /> 9-3 Monitoring Well Samnlin <br /> r <br /> On October 12, 2000, ASE associate geologist Ian Reed collected <br /> groundwater samples from each monitoring well for analysis. Prior t o <br /> sampling, the wells were purged of four well casing volumes of <br /> groundwater using dedicated bailers. The pH, temperature a n d <br /> conductivity of the purge water were monitored during evacuation, and k <br /> samples were not collected until these parameters stabilized. Samples <br /> were collected from the wells using pre-cleaned dedicated polyethylene <br /> bailers. All groundwater samples were decanted from the bailers into 40- <br /> ml volatile organic analysis (VOA) vials, preserved with hydrochloric acid <br /> and sealed without headspace. All of the samples were labeled and stored € <br /> on ice for transport to Kiff Analytical, LLC under chain of custody. See <br /> Appendix F for o a co of th <br /> Pp copy e Field Logs" k <br /> 9.4 Purge,. Water Disposal <br /> WeII development and sampling purge water were contained in 55-gallon <br /> steel drums and left on-site for temporary storage. This water will b e <br /> transported to an appropriate facility for recycling_ <br /> I <br /> 574 West Grant Line Road Report — October 2000 <br /> -8- <br /> I <br />