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Geomatrix <br /> Memorandum <br /> Hold times: EPA Method 8310 PAHs 14 days <br /> EPA Method 8290 ? <br /> Laboratory <br /> STL, West Sacramento, California will conduct the analyses of soil amples for EPA Method <br /> 8310 PAH and EPA Method 8290. STL Sacramento is sending a co irier for sample pickup. <br /> SOIL VAPOR SAMPLING <br /> Methodology <br /> A direct push rig will be used to collect depth discrete (5 feet bgs) s it vapor samples from a <br /> total of 3 locations. At each location a boring will be advanced to 5 feet bgs. Soil cuttings will <br /> not be generated. The rods and sample tip will be decontaminated tween each boring. All the <br /> soil vapor sample locations will be analyzed by method TO-15 for VOCs. <br /> Temporary Probe Installation <br /> Prior to use at each sampling location, drive rods and any other non dedicated,non-disposable <br /> equipment that may come in contact with the soil vapor sample will be decontaminated. <br /> Each soil vapor probe will be driven to the target depth and then ret acted by 4-6 inches to <br /> expose the screened sampling tip. An 8 length of disposable sampling line (1/4 to 1/8 inch <br /> diameter)will then be inserted through the drive rod into the vapor probe. The sampling line is <br /> connected to the screened sampling tip with a threaded connection containing a rubber gasket. <br /> Following the installation of the sampling line,the annulus surrounding the drive rod will be <br /> sealed at ground surface with hydrated bentonite; the top of the driv casing will also be sealed <br /> with hydrated bentonite. Since the subsurface conditions are distur ed,the available soil vapor <br /> guidelines provided by Cal EPA recommend that the probe equilibr to for at least 20 minutes. <br /> Once the 20 minute equilibration is complete, the purging will begi . The desired flow rate is <br /> 100 to 200 ml/min. The tubing length,total purge volume,purge ra e, and PID readings will be <br /> recorded. For the first sample points, a purge test will be conducted; this test is intended to <br /> ensure that a sufficient volume of air is removed and that the highes concentration of soil gas <br /> from the targeted formation is being sampled. If no VOCs are detected by the PID, a default 3 <br /> purge volumes will be extracted prior to sampling. <br /> Once the purging is complete, method TO-15 (VOCs)will be colle d in a 1 liter laboratory <br /> evacuated summa canister. Each summa canister will have a 100-200 ml/min calibrated <br /> regulator. During the sampling a leak test will be conducted with isopropyl alcohol. An <br /> isopropyl alcohol saturated rag will be placed on the bentonite seal at the base and top of the <br /> drive rod. <br /> I:\12000s\12870\H&S and SAP\SAP(Soil and Soil Vapor Sampling)10022007.doc <br /> 1281 East Alluvial,Sme 101 Tel 559164.2535 www geomatrix.cum <br /> Fresno,California 93720-2659 Fax 559.264.7431 <br />