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Passive Soil Gas and Subslab Installation and Retrieval <br /> Standard Operating Procedure (SOP) <br /> Nested Multiple Depth Passive Soil Vapor Wells: <br /> Auger or drill a 3-inch diameter hole through the slab or asphalt (if present) and into the <br /> underlying soil or fill matrix to desired maximum depth. The following figure illustrates it is <br /> important to use a spacer between wells to ensure no short-circuiting or vapor pathways exist <br /> between sampling depths. Tie a 2-inch long by 1/2 to 1-inch diameter spacer with drill holes for <br /> plastic or galvanized wire ties to each of two 1"PVC pipes (i.e. vapor wells) cut to desired <br /> lengths (e.g. 4 ft and 15ft bgs). Place soil vapor well nest into the hole and insert completely. Use <br /> a tapping dowel and hammer to push pipe a 1-inch below grade and clear soil/fill around well <br /> casing to place cement and well vault in accordance with standard well vault installation <br /> procedures. <br /> 2"x2" PVC SPACER <br /> 1" DEEPER 1" SHALLOWER <br /> VAPOR PROBE 2" 1" VAPOR PROBE <br /> O <br /> LOOSE FITTING <br /> PLASTIC TIE <br /> DRILLED HOLES <br /> TIGHTLY THREADED <br /> PLASTIC TIES <br /> BENTONITE CLAY SEAL <br /> c� 1" TO 2" ABOVE <br /> z N FILTER PACK SAND <br /> n <br /> U U <br /> TOP OF #3 FILTER <br /> c� <br /> a > PACK SAND <br /> � <br /> Y Y <br /> Z Z <br /> g g <br /> m m <br /> 2' — #3 FILTER PACK SAND <br /> TOP OF SCREEN <br /> SLOTTED PVC SCREEN <br /> BENTONITE CLAY SEAL <br /> PROPOSED "SPACER" FOR <br /> NESTED SOIL VAPOR PROBE <br /> SCALE: NONE <br /> Page 5 of 8 <br />