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'N t .24 Jarivary 1995' :.G <br /> AG&NC.Praject No`95 0114 ` ,, <br /> Page 3:of 6 - , <br /> accordance with;the'Unified Soil'Classification System(see Boring'Logs;,Appendix A): <br /> ti <br /> 3.3., WELL COMPLETION,,.- <br /> Each boring was completed as a.2-inclf dia raker gr nd'water monitoring well'using,PVC casing' <br /> .with 0.020-inch slotted screen from 28,to.48`feet:'The filter'pack.(#2-lonestar sand) was-installed <br /> from 2G to 49 feet. Hydrated bentonite chips were:used to niake,a six=footplug.and,thle remaining " <br /> y p . <br /> depth was grouted to the surface with Portland cement. <br /> 3.4.' MONITORING't�'ELL ABANDONMENT <br /> During.the•d.evelopment ofMW�3 in 1993, a surge block was lodged'inthe•well.:Since that,time, <br /> lv[W=3 has consistently failed to.produce sufficient ground water to,'meet the.,pre-sampling purge <br /> requirements requested by.the'PHS-EHD and CVRWQCB, Therefore, NAV-3 was 6.uerdrilled'cn <br /> 07 December 1995:and grouted-.to..surface grade'with Portland.cement.in' accordance,withe^ll' <br /> aliandoizment regulations established by the PHS-EHD. <br /> ' 3.5. 'MONITORING WELL PURGE PROCEDURES ` <br /> On 21 June and 19 December 1995, a.Solinst water level meter,was used to measure the depth to <br /> ' ground water in each well relative to the'top"of the casing. The.relative ground water•'elevation in <br /> each well and hydraulic gradient were determined from these•data (Table 1)'. No free hydrocarbon,:., ; <br /> product was observed in,any of the wells during the June or'December 1995 sampling events:' <br /> Pre-cleaned PVC bailers were used to purge wells MW-l;MW-2 and MW-3 during the June 1995 , <br /> monitoring. A submersible pump was used to purge wells MW-1, M1�'-2; MW-3 R,-MW,-4'and'ARAN=5' <br /> ' <br /> - during the,December 1995 monitoring, For each-monitoring event, approximately 7 to 8 gallons of <br /> ,water (minimum of three well-volumes) were.removed from each well'except MW-3, which' was <br /> ' bailed-dry.aAer removing only 2 gallons' Temperature, pH and'conductivity were�,mi.asured at 1-, <br /> gallon intervals'using an ICM water analyzer. Purged.water was stored.in 55-gallon;dr'um&on-site. ; <br /> Mbnitoring well stabilization data and'field data-sheets are included in Appendix B.:' <br /> 3.5. ' MONITORING WELL,DEVELOPMENT AND SURVEY _ <br /> On 15 December 1995, wells MW-3R,,MW-4 and MW-5 were developed using a subrnersible,purrip. <br /> Approximately 25 gallons of water were removed from well'until the extracted water was:clear'.' <br />