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0 <br /> 2.2.1 Exploratory Soil Boring (Four Borings) <br /> Prior to the start of drilling the drill rig and all down hole equipment will be decontaminated <br /> Exploratory borings will be drilled by a hollow stem auger drill rig. The hollow stem auger <br /> (HSA) drill rig will use 4.25" inner diameter(ID)by 8.25" outer diameter(OD). Soil samples <br /> will be taken every 5 feet by split spoon sampler. A field geologist will log the borehole during <br /> drilling in accordance with the American Standard for Testing and Materials ASTM)Method <br /> D2488-00, Description and Identification of Soils, Visual-Manual Procedure (ASTM, 2000). <br /> Additionally, the geologist will observe and note the soil color, relative density or stiffness, <br /> moisture content, odor(if any), and any contamination(if present). Auger cuttings will be <br /> collected and observed. The field geologist will be supervised by a California professional <br /> geologist. <br /> Volatile hydrocarbons detected by the PID will be reported in parts per million. The geologist <br /> will record all observations on the geologic boring log that will be included in the well <br /> installation report. <br /> Soil cuttings from the well boring will be dispersed on the ground next to the boring location. <br /> Drill cuttings from borings located outside of CHSL will be transported back to the landfill and <br /> disposed in an area agreed upon with landfill personnel. <br /> Soil samples will be field-monitored for total volatile hydrocarbons using a hand-held <br /> photoionization detector(PID). Samples will be sealed in a plastic baggie and left for <br /> approximately 15 minutes, which is generally sufficient for volatiles to escape from the soil. <br /> The soil boring that will be used to install permanent monitoring well MW-8 will be drilled to 15 <br /> feet below encountered groundwater in the shallow aquifer, a depth of about 85 feet below <br /> ground surface (bgs). The actual depth will be selected based on the water level encountered in <br /> the field at the well location. <br /> The three temporary soil borings will be drilled to about 75 feet bgs or 5 feet below first <br /> encountered water. <br /> 2.2.2 Well MW-8 Installation <br /> Monitoring well (MW-8) will be installed in the exploratory boring at the CSHL(Figures 2 <br /> and 4). <br /> Before installation, all well materials (exclusive of sand pack sand, bentonite and cement grout) <br /> will be decontaminated or purchased clean and sealed within plastic bags. After the boring is <br /> Corral Hollow EMP WRDOC 2.3 February 28,2007 <br />