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two foot thick sand layer was encountered at approximately 85 feet bgs. No permeable coarse <br /> grained or saturated fine-grained soil was encountered beneath this sand layer. Therefore, <br /> PSC did not install a well in this location. The boring was grouted to the surface with neat <br /> ' cement. <br /> Initially, PSC drilled and installed well CT-MW-8 to a total depth of 80 feet bgs. However, <br /> when well development was attempted it was discovered that the well was filled with filter- <br /> sand up to approximately 42 feet bgs. Apparently, the well casing or screen was broken <br /> during installation causing sand to flow into the center of the well. Based on records of well <br /> installation, the break may have occurred during installation of the sand pack. Well <br /> 1 CT-MW-8-80 was re-drilled to remove all the casing, sand, seal, and grout material. The <br /> boring was over drilled to 87 feet bgs to install a well with a screened interval intercepting the <br /> sand encountered at 85-87 feet bgs. The replacement well was designated as CT-MW-8-87. <br /> ' The work plan proposed samples to be collected from the `B" and "C" permeable zones for <br /> permeability testing at PSC's soil mechanics laboratory. Sample recovery in these zones was <br /> ' not sufficient for submittal for this testing in addition to testing scheduled for contaminants, <br /> nutrient and biological laboratory analysis. Permeability values for silty sands and sands for <br /> the evaluation were obtained from referenced sources. <br /> 2.4 Geologic Data <br /> Soil encountered in the borings was similar to soil encountered at the Site during previous <br /> investigations and was predominately silt and clay for the full depth of exploration. Silty sand <br /> and sand layers were encountered at approximately 65-87 feet bgs for borings CT-MW-8-87 <br /> and CT-8-130. Sandy layers were encountered at approximately 45-50 feet bgs, 60-64 feet <br /> ' bgs, 80-84 feet bgs, and 115-117 feet bgs for well CT-MW-9-120. Groundwater was <br /> encountered in each of the sandy layers. Water levels stabilized at approximately 20 feet bgs <br /> for CT-MW-8-87 and CT-MW-9-120. Geologic cross-sections are presented on Figures 4 <br /> ' through 7. <br /> 2.5 Soil and Groundwater Sample Analytical Results <br /> Soil samples collected during investigation activities were submitted to Mff Analytical LLC <br /> (Kiff) and analyzed for BTEX, TPH-g, five fuel oxygenates (methyl tertiary butyl ether <br /> ' [MTBE], tertiary butyl alcohol [TBA], di-isopropyl ether [DIPE], ethyl tertiary butyl ether <br /> [ETBE], and tertiary amyl methyl ether [TAME]), and duel additives (1,2-dichloroethane <br /> [1,2-DCA] and 1,2-dibromoethane [1,2-DBA]) by EPA Method 826OB. The IDW samples <br /> collected from the soil disposal drums were analyzed for all of the above as well as total lead <br /> by EPA Method 6010. Laboratory analytical data for soil samples collected during the well <br /> installation activities are included in Appendix D, and are summarized in Table 1, and on <br /> ' cross-section Figures 6 and 7. <br /> No detectable concentrations were reported for soil boring CT-MW-8-80, except for TBA in <br /> ' samples from 45 to 81.5 feet bgs. All constituents were below the detection limit for soil <br /> Boring CT-8-130. CT-MW-9-120 had detections of benzene that were above the San <br /> Francisco Bay Regional Water Quality Control Board Residential Environmental Screening <br /> ' Monitoring Well Installation <br /> and <br /> Biosparge Evaluation Report <br /> ' Prepared For:Sara Lee Bakery Group,Inc. I l Prepared By:PSC Industrial Outsourcing,LP <br /> Sane Lee—Lincoln Street 2009_12_03-MW Installation&BioSparge Evaluation Report(Final).dac Report Daze:December 3,2009 <br />