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I ' 09 January 2004 AGE-NC Project No 96-0254 ' Page 3 of 6 ' Fuel additives methyl tertiary-butyl ether(MTBE),tertiary-butal alcohol(TBA),di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), tertiary-amyl methyl ether (TAME), 1,2-dibromoethane (EDB) and 1,2-dichloro ethane (1,2-DCA)by EPA Method 8260B I 2 4 BACKFILLING OF EXCAVATION ' On 02 and 03 June 2003 the excavation was backfilled usinga combination of ea gravel, clean p �' , ' native soil removed from the excavation and imported AIB baserock I25 DISPOSAL OF HYDROCARBON-IMPACTED SOIL On 04 and 05 June 2003, approximately 1,310 tons of petroleum hydrocarbon-impacted soil was transported to Forward Landfill In Manteca,California for disposal Landfill weight tags are included as Appendix B 2 6 MONITORING WELL INSTALLATION I On 30 June 2003, monitoring wells MW-1A, MW-1B, MW-4 and MW-7 were reinstalled, all as single-completed wells, their locations are shown on Figure 2 Pilot borings were advanced using a truck-mounted hollow stem drill rig equipped with S 25-inch augers The pilot borings for MWA B and MW-4 were advanced to approximately 15 feet bsg,pilot borings for MW-IA and MW-7 were advanced to approximately 28 feet bsg and 41 feet bsg,respectively The drill rig and two-man crew were supplied by Mitchell Drilling Environmental Auger returns generated by drilling were stored In properly labeled DOT-approved model 17H 55-gallon drums pending laboratory analysis The wells were completed as ground water monitoring wells utilizing 2-inch PVC casing with 0 020-inch slotted screen installed from approximately 5 to 15 feet bsg in wells MW-1B and MW-4, from 22 to 27 feet bsg In well MW-IA and from 36 to 41 feet bsg in well MW-7 Blank casing was I utilized from the top of the screened-interval to surface grade for each well The filter pack(No 2/12 sand) was installed from total depth to approximately 2 feet above the screened interval of each well A nominal 2-foot bentonite chip plug was installed above the filter pack in wells MW-IB and I MW-4, a 3-foot bentonite chip plug was installed above the filter pack in wells MW-1A and MW-7 The bentonite chip plug was allowed to hydrate for approximately 30 minutes Following installation of the bentonite plug,the wells were then grouted to near surface grade with portland cement Water- tight,traffic-rated well boxes were then installed over the wells As-built well diagrams are depicted on the boring logs in Appendix C Advanced Geo EnVLronmental,Inc