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C <br /> SECTION 3 - <br /> Sampling Methodologies and Analytical Plan <br /> rThis section presents the sampling methodologies and techniques to be followed in conducting <br /> s-' this focused field investigation. The sample analytical plan is also presented. <br /> 3.1 Sampling Methodologies <br /> r 3.1.1 Cone Penetrometer Testing (CPT) <br /> L All borings installed during this field investigation will be installed using a CPT drill rig.CPT <br /> lithologic logging will be conducted using a standard electronic piezocone (CPTU).CPTU <br /> measurements of cone bearing,sleeve friction,and dynamic pore water pressure will be <br /> recorded at 5 cm intervals for the entire length of each boring. An ultra-violet induced <br /> fluorescence (UVIF)module will be used in addition to the CPTU to log the borings installed <br /> I in the former tank and pump area. The UVIF module detects the presence of petroleum <br /> hydrocarbons in soil and groundwater and will be used as a screening tool to provide <br /> information about the vertical distribution of petroleum hydrocarbons. <br /> I CPT borings will be installed at 7 locations on the Disco site. Five borings will be installed <br /> !•" upgradient, downgradient,and within the former tank and pump area,and 2 borings will be <br /> installed downgradient of the site as shown in Figure 2. The downgradient borings will be <br /> installed in the shoulder area of Highway 4,approximately 140 feet downgradient from the <br /> former tank and pump area. CPT logs will be obtained in each of the borings to a depth of <br /> j approximately 150 feet,if possible. If refusal is met during CPT logging prior to attaining the <br /> I target depth,one additional attempt will be made at each location by moving a short distance <br /> G <br /> from the original location and making one more attempt. If the second attempt fails,CPT <br /> logging in that location will be abandoned. <br /> Prior to beginning field work,boring permit applications will be submitted to PHS for <br /> approval, all boring locations will be marked and Underground Service Alert (USA) will be <br /> notified,and approval from Cal Trans for work in the shoulder area of Highway 4 will be <br /> obtained. <br /> E 3.1.2 Soil and Grab Groundwater Sampling <br /> Adjacent to each of the seven CPT borings,additional borings will be installed to obtain soil <br /> and grab groundwater samples. These borings will be completed using direct push methods <br /> that are compatible with the CPT sampling rig, as described below.The exact sampling depths <br /> t� will be determined in the field by the onsite field geologist based on the CPT lithologic and <br /> r UVIF logs. <br /> IRy <br /> The location,depth,and rationale of each soil and groundwater sample are described below. <br /> Soil Sampling <br /> Soil samples will be collected using a piston-type sampler.The sampling tool is pushed in the <br /> 'closed' position to the desired sample interval.The inner cone tip portion of the sampler is <br /> then retracted approximately 12-inches,leaving a hollow so II sampler containing two inner <br /> L 1.25-inch diameter by 6-inch long stainless steel soil sample tubes. The hollow sampler is then <br /> SFO/CABERNET/GRWP$/EBGIDELMONTE/PLPNT_33MORKPUW_CPT.DOC 5 <br /> t <br />