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5 <br /> Z3 Field Investigation <br /> The scope of work for this project included an underground utility location survey and the <br /> advancement of two soil borings using Cone Penetrometer Testing (CPT) methods Details of <br /> the investigation methods are presented in the following sections <br /> 2.3.1 Underground Utility Location Survey <br /> On February 11, 2002, an underground utility location survey was conducted to assess the <br /> absence or presence of unreported underground utilities at the site The utility survey was <br /> conducted using ground-penetrating radar (GPR) and radio frequency survey equipment The <br /> utility survey cleared utilities for the proposed CPT boring locations <br /> 2.3.2 Drilling and Groundwater Sample Collection <br /> Two borings were advanced to 30 5 meters (100 feet) using a truck mounted Cone Penetrometer <br /> Testing (CPT) rig A boring location map is presented in Figure 2 The boring locations were <br /> selected by Caltrans to provide data for determining the vertical extent of contamination The <br /> CPT borings were performed to obtain deep lithologic data on the aquifer and to collect discreet <br /> groundwater samples As the first boring was advanced, cone bearing tip resistance, sleeve <br /> friction, friction ratio, and pore water pressure were measured using the cone penetrometer tip <br /> Using the CPT results, subsurface conditions were interpreted in order to determine aquifer <br /> zones to collect groundwater samples from The CPT log indicated that potential water bearing <br /> zones were located at 19 8 meters (65 feet), 27 4 meters (90 feet), and 30 5 meters (100 feet) <br /> Based on the CPT data, Zone A includes a very stiff fined grained sand observed between <br /> 117 and 13 4 meters (38 5 and 44 feet) BGS, and again between 18 1 and 18 5 meters (59.5 and <br /> 61 feet) BGS Zone B includes a silty sand to sandy silt observed between 20 1 to 210 meters <br /> (66 to 69 feet) BGS and a very stiff fine grained sand observed between 210 and 25 0 meters (69 <br /> and 82 feet) BGS Chemical concentrations detected in the HydroPunch® sample collected at <br /> 27 4 meters (90 feet) BGS was applied to this zone Zone C includes very stiff fine-grained sand <br /> observed between 27 1 and 30 5 meters (89 and 100 feet) BGS <br /> r <br /> The second boring, SC-1, was advanced to obtain groundwater samples from the targeted zones <br /> using HydroPuncO methods <br /> Groundwater samples were collected from each of the zones using HydropuncO methods The <br /> samples were collected by advancing approximately 1 meter (3 3 feet) below the targeted zone <br /> and raising the probe to expose the 1 5-meter (5-foot) screen New disposable polyethylene and <br /> stainless steel bailers were used for groundwater collection The groundwater samples were <br /> N �zaozw�natss� nzae 2-2 <br /> s�r�.nz <br />