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R603 UPDATE-10 11/09/92 3. 2 VAPOR RECOVERY VAPOR RECOVERY SYSTEM AND MONITORING As stated in Update Status Report #5 , monitoring wells MW1, MW2, MW3 , MW10 and the excavation 6 inch (EX-411 ) have been individually manifolded to a vapor extraction system with individual valved orifices for flow control sampling and vacuum and flow measurements from the individual wells. MW2 and MW3 are manifolded together with 211 tubing T ' ed at the wells, but can be individually tested by placing a packer below the extraction T of the well to seal that well from the vacuum system. The individual wells are fitted with a PVC "T" head with an air tight cap for well access. The 'IT" lateral (211 ) is fitted with a 1/4" pipe to tubing fitting for obtaining vacuum/pressure and temperature readings. Wells MW2 , and EX-41' are fitted with a pipe to hose 2" fitting placed between the 'IT" and the 2" PVC flex hose that goes from the well to their individual condensation drop outs that hook into the extraction manifold. The 3" SCH 40 PVC lateral from MW3 is also fitted with a 2" pipe to hose fitting where it enters the traffic box near MW2 and is T' ed to the 2" tubing from MW2 at that • point. MW1 is fitted with a 2" PVC Y to allow access to the well from the straight leg of the Y and vapor recovery from the angled leg of the Y. The vacuum recovery piping from this point rises 7 feet into the air prior to an 90 degree elbow connecting 2" PVC pipe at a slight incline towards the eastern fence of the compound, 8 feet above the surface. At this point the PVC pipe drops into the condensation drop out tank for MW1, prior to the vacuum extraction manifold. MW10 is manifolded to the treatment compound via SCH 40 PVC pipe underground west towards the store. Once the pipe reaches the store it connects into a condensation drop out tank (Approximately 5 gallon capacity) prior to heading over the roof of the store with 2" galvanized pipe. The condensation tank is below ground in a concrete lined traffic box. The condensation collected in this tank is removed weekly via an air tight valve attached to the top of the air tight lid of the tank. Once the pipe reaches the roof of the store, it 90 degree elbows into SCH 40 W protected PVC pipe and heads across the roof towards the treatment compound. There it 90 degree elbows down the wall into a second condensation drop out tank prior to the manifold. At the manifold the individual wells , condensation tanks are connected to their own 2" PVC riser ( 36" in height) with an orifice plate and a gate valve at the top of the riser. Vacuum/pressure ports are located on either side of the orifice piaze. Each orifice kwell has iT-s own manome-cer kcalibra-ced in millimeters (mm) oil ) which are hooked to the ports for continuous • measurement of flow from a particular well , or in the case of MW2 and MW3, combination of wells. All the extraction wells are manifolded together above the gate valve to a 4 inch orifice riser PAGE 5