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------------- <br /> '&Rdb <br /> engineered for a set depth. A-soil and groundwater sample will be collected at the bottom of the <br /> excavation and analyzed for: <br /> TPH g and TPH d by EPA method 8015M,and <br /> Benzene, toluene, ethylbenzene, total xylenes (BTEX) and MTBE by EPA Method 8021. <br /> 4.3 Excavation Volumes <br /> The proposed excavation will generate approximately 230 cubic yards or 370 tons of soil. It 15 <br /> estimated that up to one excavation volume of water(one volume is 10 feet x 25 feet x 6.5 feet) <br /> will be removed after soil excavation, or approximately 12,000 gallons of water. The soil will be <br /> stockpiled and characterized for onsite re-use and/or offsite disposal. Previous sampling <br /> indicates that the top 15 feet of soil is not contaminated and can likely be reused to backfill the <br /> excavation We anticipate that sidewalls will require shoring similar to that used during the <br /> Previous deep excavation at the site. Clean import material will be used to replace contaminated <br /> soil that can not be re-used to backfill the excavation. Backfilling procedures will be determined <br /> by the project geotechnical engineer. <br /> 4.4 Remediation Schedule <br /> We can begin the excavation as soon as this workplan is approved by the SJCEHD. The <br /> excavation would take approximately one week to shore and another 2 to 3 days to excavate. <br /> The excavation will likely remain open 2 to 5 days to complete the dewatering. Backfilling,re- <br /> compaction and shoring removal will take an additional 4 to 7 days. <br /> 5.0 PROPOSED GROUNDWATER MONITORING <br /> 5.1 Well Installation and Monitoring <br /> Three monitoring wells will be installed at locations CMW-1, CMW-2 and CMW-3 shown on <br /> Figure 3. The well locations were selected to better characterize the extent of the groundwater <br /> 6 <br /> 25970122.DGD <br /> 14 February 2005 <br />