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5 <br /> TreadvvelURolb <br /> • Collecting a soil and groundwater sample from the base of the shored excavation for <br /> ' laboratory analyses, <br /> • Placing approximately 500 lbs of ORC into the base of the shored excavation prior to <br /> 1 backfilling, <br /> • Excavating soil from the former pump islands and collecting three sidewall and two <br /> bottom confirmation samples, <br /> • Backfilling and compacting clean imported soil in the excavation, and <br /> • Disposing of the excavated soil at Forward Landfill in Stockton, California <br /> 5.1 Shoring and Soil Excavation <br /> Prior to shoring the excavation, three USTs were removed from the site on 28 April 2004 <br /> (Figure 2) The UST removal activities were overseen by a Treadwell &Rollo representative <br /> under the direction of representatives from the SJCEHD The details of the UST removal <br /> activities are documented in Treadwell &Rollo's report titled Confirmation Soil Sampling UST <br /> Removal Activities, Former Carando Machine Shop, North Shore Parcel, Stockton, California <br /> dated 11 June 2004 On 10 June 2004 through 16 June 2004, all perimeter edges of the <br /> excavation were shored with metal sheet piles The excavation dimensions inside the shoring <br /> ' was 42 feet long, 13 feet wide and 25 feet deep Since the USTs were removed and the <br /> excavation was not backfilled prior to shonng, the excavation was started at approximately 4 feet <br /> below grade (Treadwell &Rollo 2004b) Therefore, the actual volume of soil excavated during <br /> this scope of work was smaller than originally estimated Approximately 425 cubic yards of soil <br /> ' were excavated and stockpiled for charactenzation Mr Jeff Wong of the SJCEHD was on-site <br /> to observe the excavation Since the excavation perimeter was shored, confirmation samples <br /> were not collected from the sidewalls On 16 June 2004, one soil confirmation sample was <br /> collected from the bottom of the excavation at 25 feet bgs (Figure 2) In addition,one <br /> ' groundwater sample was collected from the bottom of the excavation following two days of <br /> dewatering Results of the soil and groundwater confirmation samples are presented in <br /> Section 5 4 <br /> 25971020 DGD 6 23 August 2004 <br />