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25 April 2007 <br /> AGE-NC Project No. 95-0106 <br /> Page 4 of 5 <br /> 3.2. SOIL SAMPLING COLLECTION AND ANALYSIS <br /> Soil borings will be sampled at three feet bsg with a 1.125-inch Geoprobe soil sampling assembly <br /> loaded with four six-inch brass sleeves. Upon sample retrieval, the ends of the second sleeve will <br /> be covered with Teflon sheets, capped and sealed with tape. <br /> Appropriately sealed and labeled samples will be placed in a chilled container under ice and <br /> transported under chain-of-custody procedure to a DHS-certified laboratory.Each sample sleeve will <br /> be labeled with the boring designation,depth,time,date and sampler's initials. Soils encountered in <br /> the borings will be visually classified by an AGE geologist in accordance with the Unified Soil <br /> Classification System(USCS).Additionally,soil samples will be field-screened for the presence of <br /> volatile organic compounds using an organic vapor meter(OVM),equipped with photo-ionization <br /> detector(PID). <br /> 3.3. SOIL-VAPOR SAMPLING COLLECTION AND ANALYSIS <br /> Soil vapor samples will be obtained at a depth of approximately five feet bsg in each soil vapor <br /> boring.Samples will be collected using a Geoprobe soil vapor assembly.An expendable vapor point <br /> will be placed into a point holder at the bottom of a string of 1-inch diameter hollow drive rods.The <br /> assembly will then be advanced to the specified depth and retracted between six inches to one foot, <br /> in order to engage the expendable point and expose a column of strata from which soil vapor can be <br /> extracted. A post run tubing adapter equipped with an O-ring to ensure a vacuum-tight seal is then <br /> attached to a'/4-inch diameter,single use,disposable polyethylene tubing.The sampling tube is then <br /> lowered through the center of the hollow drive rods and secured by threading into the expendable <br /> point holder. The probe rod is retracted a minimum of two feet, placing the expendable tip in soil <br /> and creating a void open boring. <br /> Above ground,the polyethylene tubing is attached to a vacuum sampling chamber.A Tedlar bag will <br /> be placed into the vacuum chamber. The sampling tube will be attached directly to the Tedlar <br /> sampling bag,through a collapsible,air tight port.The vacuum chamber is then sealed.The vacuum <br /> will then be used to purge the exposed soil column,through the sampling tubing,until approximately <br /> three volumes of soil vapor or ambient air is evacuated through the sampling system. The vacuum <br /> is then applied to the chamber,creating a negative pressure on the exterior of the sample Tedlar bag. <br /> The bag then fills with vapor from the subsurface, allowing the sample to enter directly into the <br /> Tedlar bag. On complete collection of the vapor sample, the negative pressure in the chamber is <br /> reduced and the sampling bag sealed. Upon collection, each sample will be labeled, logged on a <br /> chain of custody form and place into a dry cooler. Samples will be delivered to a State-certified <br /> laboratory for analysis of volatile organic compounds(VOCs)to include1�I EX in accordance with i�.e <br /> EPA Method 8260B. / U P <br /> Advanced GeoEnvironmental,Inc. t f <br />