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The sampling procedure requires one end of the tubing to be slipped over the sampling port and the other end over the canister nozzle or flow meter (if required) to acquire an air- tight connection. The valve should be opened at this time and the initial pressure should then be recorded,to verify that the Summa canister is under vacuum. The Summa canister is allowed to collect the soil vapor sample at a predetermined duration. After the sample has been collected record the final vacuum reading (approximately five pounds per square inch (psig)) to ensure that the flow meter was working properly, if applicable. Immediately following the sample collection, complete sampling information is recorded on the label on the air sampling canister (e.g., sample ID, date, time, location, and temperature). The sample is placed in a non-refrigerated, dry cooler with sufficient packing to ensure against damage during transport. Cooling samples will cause condensation of any moisture within the air sample, thereby distorting laboratory analysis. Summa canister samples are subject to hold times of typically 30 days and with some compounds a more rigid hold time of 14 days is required. SOP-13 SOIL VAPOR SAMPLING: SYRINGE SAMPLING TECHNIQUE Prior to vapor sampling, the vacuum system must reach a stabilized air flow (cubic feet per minute) for approximately 15 minutes. Prior to the actual collection of the vapor sample, the following data is recorded: airflow, temperature, and pressure at collection ports and gauges. The sampling equipment consists of a clean, 100cc, gas- tight syringe and silicone septa. The sampling ports are brass connections, fitted with silicone septa, and threaded into a tapped hole in the system piping. Samples are collected by inserting a clean syringe into the septum and the plunger actuated several times. Each syringe should be purged of three syringe volumes before collecting the sample. On the fourth purge, the plunger is extracted slowly until the syringe is filled with a gas sample, then the syringe is withdrawn and the needle immediately plugged with a silicone stopper. The sample should be placed in a non-refrigerated, dry cooler with sufficient packing to eliminate breakage during transport. Cooling samples will cause condensation of moisture, thereby distorting laboratory analysis. Duplicate air samples should be collected as in SOP-10. Vapor samples are also subject to the same hold times and must be stored as stated in SOP-10. SOP-14 SOIL VAPOR SURVEY SAMPLING: "TEDLAR" BAG SAMPLING TECHNIQUE The sampling equipment consists of a "Tedlar" bag (available in 1, 3, 5, and 10 liter sizes), an SKC universal sample pump, soil vapor probe, and 1/4-inch-diameter polyethylene tubing (approximately three feet long). A Roto-hammer or slam bar is used to obtain a three foot hole into the ground area, where the soil vapor sample will be collected. Once the hole has been formed the soil vapor probe will be inserted into the hole and advanced the remaining two feet, five feet total below ground surface (bgs), with the use of either a slide hammer, using a tee adapter and using physical force. Once the vapor probe has been inserted into the ground a bentonite seal must be formed between ambient air and the sample air. The bentonite must be hydrated and create an air tight seal around the probe. If required IPA can be placed on the joints of the vapor probe and analyzed for in the sample to ensure that ambient air is not diluting the soil vapor survey samples. Once the sample apparatus has been set up new tubing will be connected to the inlet of the SKC sample pump. The pump operates at a low flow purge rate of 200 milliliters per minute to prevent air stripping of contaminants from the soil. Once three volumes have been evacuated (minimum 4.2 minutes of sample time) a sample can be collected. Verification with a PID will determine when the maximum concentration is obtained and a sample should be collected. If measurable concentrations are not obtained with the PID after 7 purge volumes (10 minutes) a sample should be collected. Once a sample has been determined to be collected new tubing will be placed on the effluent of the sample pump running to the Tedlar bag, which should be filled to 3/4 of volume capacity. Caution should be taken not to overfill the sampling bag. The sample is placed in a non- refrigerated dry cooler with sufficient packing to eliminate damage during transport. Cooling samples will cause condensation of moisture within the sample, thereby distorting laboratory analysis. To minimize the potential for cross-contamination between air samples new polyethylene tubing will be used for every sample. Vapor samples are also subject to the same hold times and must be stored as stated in SOP-10. SOP-15 SOIL GAS SAMPLING FROM DIRECT PUSH SOIL BORING: "TEDLAR" BAG SAMPLING TECHNIQUE To obtain soil gas samples from a direct push drill rig, advance a discreet sampling rod with a 6-inch retractable vapor screen to the desired sample depth. Release the sample screen cover from the screen and retract the rod 6- inches. Place a dry bentonite powder layer in the annulus to seal the borehole from surface air interference. Tamp the bentonite powder, place a hydrated bentonite layer in the annulus, and follow with a second dry bentonite layer. Attach the soil gas sampling diaphragm pump to the rod casing using polyethylene tubing. The sampling equipment consists of a Tedlar Tm bag (available in 1, 3, 5, and 10 liter sizes), a diaphragm pump, and 3/16-inch-diameter polyethylene tubing (approximately 1 foot long). The TedlarTm bag should be fitted with an integral valve for filling and sealing the bag after sampling. The diaphragm pump inlet and outlet are fitted with 3/16-inch hose barbs for attaching the sample tubing. A sample label with the sample number and date and time of sample collection is prepared and placed on the TedlarTm bag. The sampling procedure requires one end of the tubing be slipped over the direct push drill rod sample port hose barb and the other end over the diaphragm pump inlet hose barb to form an air-tight connection. The sampling pump is then started and the pump is purged for 1 minute with the vapor to be sampled. Following purging, the discharge of the pump is then connected to the TedlarTm bag using a section of 3/16-inch tubing. The pump is restarted and the bag is opened and allowed to fill to approximately 3/4 of its capacity. Caution should be taken not to overfill the sampling bag. The sample is placed in a non-refrigerated dry cooler with sufficient packing to prevent damage during