SITE INFORMATION AND CORRESPONDENCE

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• • Page 4 of 5 200 milliliters per minute (ml/min); a stainless steel tee-fitting; two vacuum gauges at either end of the flow controller and connections for both purge and sampling canisters(manifold assembly). The manifold assembly will be attached to the Teflon tubing from the vapor implant; for the duplicate TO-15 sample, a tee-fitting will be used to attach the tubing to two separate manifold assemblies. The purge canister will be attached to the end of the sampling manifold while the sample canisters will be attached to the tee-fitting between the tubing and purge container. A manifold assembly will not be used for sorbent tube sample collection. The inlet of the sorbent tube will be attached directly to the Teflon tubing and a low-flow pump will be attached to the outlet of the sorbent tube. The low-flow pump will be calibrated to approximately 100 ml/min and will used to extract soil-vapor through the tubing and into the sorbent tube. Approximately four liters of soil-vapor will be collected into each sorbent tube. This step will repeated for collection of a replicate TO-17 soil-vapor sample. \ Leak tests will be performed on each assembly by attaching and securing the sample and purge canisters to the manifold and opening the valve on the purge canister and the manifold. The leak test will be performed for approximately 10 minutes on each assembly. The soil-vapor boring location will be isolated from ambient air by enclosing the borehole, tubing and manifold/canister assembly in a plastic shroud, which will be weighted at the surface. Isopropyl alcohol (IPA) as a liquid will be placed in a stainless steel bowl within the plastic structure and allowed to volatilize into the air enclosed within the plastic structure surrounding the borehole, tubing and manifold/canister assembly. Upon achieving a successful leak test and allowing for 120 minutes of equilibration time, the purge canister valve will be opened for a calculated period of time to allow for three calculated volumes of air to be purged. The purge canister vacuum gauge will be monitored to ensure a proper decrease of vacuum ensuring flow and purging. The purge volume will be determined by calculating the internal volume of the tubing, vapor implant and the volume of sampling void. Upon achieving the targeted purge volume, the purge canister valve will be closed and the sample canister valve will be opened. The initial pressure and time will be recorded. UponN'y reaching at least-5 in Hg or less, the sample canister valve will be closed and final pressure 'V and time recorded. The sampling port on the sampling canister will be capped with a brass end-cap. For TO-17 analysis the tow-flow pump will be activated and allowed to operate for approximately 40 minutes 100 ml/m1b to recover approximately 4 liters of soil-vapor. The initial start time and comp) ime will be recorded and the sorbent tube will be capped with brass end-caps. The samples will be transported under chain-of-custody procedure to a CDPH-certified laboratory. Each sample canister and tube will be labeled with sample designation, time, date and sampler's initials and analyzed for the constituents listed in Section 2.3. Additionally, sorbent tubes will be placed in a chilled container for transport and include a trip blank for TO- 17. Vicki, with this new method of soil-vapor sample collection the only materials being used is the Polyethylene Vapor Implant with Speed-Fit Fitting and 0.25-inch diameter Teflon tubing. Both products we have been purchasing from Environmental Service Products (ESP): 1) The Polyethylene Vapor Implant is listed as Item#SVPT91-14 on the ESP website------ ----------http7//www envservprod com/Polyethylene-Vapor-Implant-with-Speed-Fit- Fittinq-P1932C5.asox 2) The 0.25-diameter Teflon Tubing is listed as Item#T250TEF on the ESP website-------- ---http-//www.envservprod.com/storerTeflon-Tubing-316-x-1 4-OD-per-foot-P24C5.asPx Material Blank Case: 8/8/2014