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TreadvvelUMb <br /> ' 5.2 Groundwater Extraction,Treatment and Disposal <br /> Approximately 20,000 gallons of groundwater were pumped from excavation and stored in a <br /> Baker Tank prior to analysis and discharge The results of the groundwater analyses met the <br /> requirements of the City of Stockton Municipal Utilities Department(SMUD) for discharge into <br /> the Sanitary Sewer Laboratory analytical results are included in Appendix B SMUD accepted <br /> the groundwater for discharge in a 7 July 2004 permit that is included in Appendix C <br /> 5.3 Pump Island Excavation <br /> ' On 25 June 2004, Treadwell &Rollo excavated four test pits (TP-A through TP-D) along the <br /> footprint of the former pump islands to determine if there was hydrocarbon contamination from <br /> leaking fuel pipelines (Figure 2) Based on field observations of soil color, odor, and approval <br /> from Jeff Wong, TP-A was sampled at 4, 7, and 10 feet bgs, and TP-B was sampled at 4 and <br /> 10 feet bgs <br /> All three soil samples from beneath TP-A and the four foot sample beneath TP-B had elevated <br /> TPH-d results Following review of analytical results, the soil from the test pits was excavated <br /> on 1 July 2004 to an mitial depth of 10 feet The geotech excavation, which removed the upper <br /> four feet of soil, was conducted at the site (Figure 2) prior to beginning our pump island <br /> ' excavation Additional soil was excavated to depths of up to 19 feet based on visual and <br /> olfactory indicators of contamination <br /> Sidewall confirmation samples were collected on the north, west, and south walls at depths of 15, <br /> 8, and 10 feet respectively Analytical results for samples from previous bonngs CSB-4 and <br /> CSB-5 contained no or low petroleum hydrocarbon concentrations,which provided excavation <br /> limits for the northwest and southwest portions of the excavation A sidewall sample was not <br /> collected from the east wall as this was a ramped area required for OSHA regulations Two <br /> ' bottom confirmation samples (CPT-EXC-BT12 and CPT-EXC-BT19)were collected at depths <br /> of 12 and 19 feet bgs Elevated concentrations of TPH-g and TPH-d were only detected in the <br /> bottom confirmation sample CPT-EXC-BT-19, which was collected from the deepest part of the <br /> 25971020 DGD 7 23 August 2004 <br />