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i <br /> 2.0 Site investigation Scope of Work <br /> Shaw utilized HydroPuncho and Geoprobe° groundwater and soil sampling, from a direct-push <br /> drill rig and a Membrane Interface Probe (MIP) to further delineate the extent of residual <br /> hydrocarbon in the vicinity of the former UST systems The locations of the borings are <br /> indicated on Figure 2, "Site Map" All drilling work was performed by Vironex, Inc <br /> Details of these activities are summarized below The field and laboratory procedures used <br /> during this investigation are described in Appendix B, "Field Procedures" <br /> 2.1 Pre-Field Activities <br /> Shaw obtained the Well Permits from the San Joaquin County Environmental Health Department <br /> for all potential borings to be constructed during the March investigation An Encroachment <br /> Permit was also obtained from the City of Stockton for temporary lane closure on Lincoln Street <br />' plan to <br /> Shaw visited the property to prepare a health and safety safely y implement the work To <br /> assist in the avoidance of underground utilities, Shaw contacted Underground Service Alert at <br /> least 48 hours prior to the initiation of drilling activities and subcontracted Cruz Brothers <br /> Locators to clear all boring locations <br /> 2.2 Real-Time Direct Push Characterization <br /> 2.2.1 Conductivity Testing <br /> MIP Exploratory borings were pushed in 8 locations to maximum depths of 66 9 feet below <br /> ground surface (bgs), on March 27, 28, 29, and 30, 2006 Five borings were made within the <br /> property and three were made beyond the eastern edge of the property, about 8 feet into the <br /> southbound curb lane of Lincoln Street Conductivity logs were completed for each of the <br /> borings using down hole probes that measured the formation conductivity as the probe was <br /> advanced downward Lithologic properties may be inferred from the MIP conductivity <br /> Materials with higher conductivity are inferred to be composed of finer gram sizes and those of <br /> lower conductivity are inferred to be composed of coarser grained material (Appendix C, <br /> "Vironex Environmental Field Services Report") <br /> 2.2.2 Measurements of Contaminant Response with Membrane Interface Probe <br />' The MIP is a device that is advanced downward in one-foot vertical intervals It heats up <br /> subsurface material proximal to the MIP probe The vapors generated by the heating are carried <br /> in a stream of nitrogen gas to aboveground analytical equipment for analysis The MIP utilizes <br /> an Electron Capture Detector (ECD), Photo Ionization Detector (PID), and Flame Ionization <br /> Detector (FID) to test for concentrations of double-bonded compounds present in gasolines and <br /> N VTecAPUN12022f Dan Rodger9 Rpfs0RGpnng2006 SIR(AugusV doc 2-1 <br />