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ATTACHMENT A <br /> SOIL SAMPLING DURING DRILLING <br /> Soil samples will be collected duan; the drilling operations for three reasons (1) for field <br /> identification of the borehole lithology, (2) for qualitative field screening for the presence of <br /> contaminants, and (3) for chemical analysis <br /> For purposes of collecting soil samples for lithologic identification and for field screening, <br /> soil samples are collected every 5 feet from each borehole The soil samples will be examined <br /> in the geld and classified according the Unified Soil Classification system In addition to <br /> evaluating the borehole Iithology, the soil samples will be screened in the field with a <br /> phototonization detector (PID) or similar instrument, and the relative permeability of the soil will <br /> be qualitatively estimated The lithology, PID reading, and estimated permeability of each <br /> sample will be recorded on the borehole log next to the depth interval from which the sample <br /> was obtained <br /> Soil samples for laboratory chemical analysis will be collected at 5-loot intervals, at a <br /> . minimum, to the total depth of the boring The samples will be obtained using a 2-inch-diameter <br /> by 18-inch-long split-spoon sampler lined with three 6-inch-lona thin-walled brass tubes The <br /> sampler will be driven its enure length into undisturbed soil, either hydraulically or by a 140- <br /> pound drop hammer <br /> When the sampler is extracted from the borehole, the brass Lubes will be removed and the <br /> ends of the tubes will immediately be screened for the presence of hydrocarbons with a PID or <br /> equivalent instrument One sample per 5-toot sampling interval will be selected for possible <br /> chemical analysis on the bans of the highest PID reading The ends of the selected brass tube <br /> will be (1) covered with aluminum toil and plastic caps, which will then be taped with plastic <br /> tape to provide an air-tight seal, (2) labeled and placed into zip-lock plastic bags, and (3) stored <br /> in a cooled ice chest for delivery to the analytical laboratory These procedures minimize the <br /> potential for cross contamination and volatilvalion of volatile oto=anu, compounds prior to <br /> chemical analysts <br /> Toprevent cross contamination during sampling, all equipment will be washed with <br /> laboratory-;rade detergent, rinsed with tap water, and rinsed with deionized water before and <br /> between collecting each sample <br />