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• 2000 Analytical results for drilling wastes are included in Tables 2 through 4 Chain of custody <br /> documentation and laboratory data sheets are,Included in Appendix N <br /> Groundwater purged from newly installed monitoring wells was contained separately in 55-gallon <br /> drums pending analytical results Based upon the analytical results, the water purged from wells <br /> MW7, MW8, and MW9(B) will be discharged directly to the ground surface The water purged <br /> from wells MW5 and MW6 will be transported off-site for disposal or recycling at a licensed <br /> transportation, storage, and disposal facility (TSDF) <br /> 7.0 SUMMARY AND CONCLUSIONS <br /> The stratigraphy encountered during the recent phase of investigation is generally consistent with <br /> previously drilled borings Shallow groundwater beneath the site appears to exist within two <br /> primary water bearing units a laterally continuous sand lying between the depths of approximately <br /> 52 and 65 feet bgs, and a deeper sand unit encountered in well MW9(B) between the depths of <br /> approximately 122 and 130 feet bgs Based upon groundwater elevation measurements, a slightly <br /> downward vertical gradient exists between the shallow water table (approximately 58-60 feet bgs) <br /> and the 120-foot aquifer <br /> The lateral extent of groundwater contamination beneath the site has been essentially defined, with <br /> the exception of the northeastern extent of the dissolved MTBE plume Dissolved contamination in <br /> the upper water-bearing zone does not appear to extend to deeper zones based upon the absence of <br /> dissolved gasoline constituents, including MTBE, in well MW9(B) Well MW9(B) is located <br /> approximately 20 feet closer to the former USTs than A Zone well MW6, which contained 20,000 <br /> ppb MTBE in October 2000 <br /> The apparent groundwater depression in the vicinity of well MW4 in October 2000 may have <br /> resulted from operation of the facility well However, it could be an indicator that some vertical <br /> leakage of the shallow aquifer is occurring through the water supply well <br /> 8.0 RECOMMENDATIONS <br /> Ground Zero recommends accelerating the schedule to drill a replacement water supply well and <br /> 12 <br /> data/groundzeltuleburg/reports/mud_has_we1ImporLdoc <br /> I <br />