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transport. Cooling samples will cause condensation of trailer consist of an air compressor, two 150-gallon moisture within the sample, thereby distorting the laboratory polyethylene tanks, pneumatic pumps, and hoses. analysis. The injection hoses are attached to the desired injection To minimize the potential for cross-contamination between wells via an injection access point. The injection access air samples, the polyethylene tubing is replaced with new point consists of/2-inch stainless steel tee which screws into tubing. a coupling attached to the injection well and injection hose. The coupling is glued to the injection well at least 48 hours Vapor samples are also subject to the same hold times and prior to the injection even to ensure the PVC glue has time to must be stored as stated in SOP-10. properly set and the well elevation is resurveyed. SOP-16 After the injection hoses are attached to the desired wells, SOIL GAS SAMPLING FROM SOIL VAPOR POINT the trailer-mounted tanks are filled with potable water from an onsite source. As the tanks fill, the chemical oxidant is Installation of a soil vapor point may be performed with a mixed into the tank. The amount of oxidant mixed in the hand auger or truck mounted auger drilling rig. Once the tank is dependent on the desired concentration of the boring has achieved the desired depth, a 6-inch long slotted solution. After the tanks have been filled, the trailer-mounted probe, capped on both ends with one end fitted with a air compressor is started and air is supplied to the pneumatic Swagelok fitting attached to 3/16-inch diameter Nylon tubing pumps. The pneumatic pumps force the solution into the of desired length is placed in the boring and 12 inches of well through the injection hoses at a maximum of 20 pounds filter pack placed in the annulus. A layer of dry bentonite per square inch gauge(psig). The pressure of injection is powder or chips, followed by a layer of hydrated bentonite, controlled by a valve and can be reduced, if necessary to and a final layer of dry bentonite powder or chips will be avoid damaging the well and well seal. Additionally, each placed in the annulus above the filter pack. Excess tubing at injection access point is equipped with a pressure gauge to the top is coiled and placed in a flush finished well box. monitored the pressure at each injection well individually. Soil vapor samples will be collected no sooner than one After the total volume of solution has been injected, the week after probe installation to permit soil vapors to tanks are washed down with potable water to remove any accumulate within the probe. Soil vapor sampling will occur chemical residue from the tank. The rinsate water is then after a minimum of five consecutive precipitation-free days injected into the well to clean out the hoses. After the and after any on site irrigation has ceased. injection activities have terminated, the injection access points are left on the wells to ensure that pressure in the The sampling equipment consists of a TedlarTm bag wells declines to background levels prior to removing the (available in 1, 3, 5, and 10 liter sizes), a diaphragm pump, access points and hoses. A pressure relief valve is located and 3/16-inch-diameter polyethylene tubing (approximately 1 on the access points to relieve any excess pressure above foot long). The TedlarTm bag should be fitted with an integral 20 psig. 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 the end of the tubing from the probe be connected to 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 transport. Cooling samples will cause condensation of moisture within the sample, thereby distorting the laboratory analysis. To minimize the potential for cross-contamination between air samples, the polyethylene tubing on the discharge side of the pump is replaced with new tubing. Vapor samples are also subject to the same hold times and must be stored as stated in SOP-10. SOP-17 PRESSURIZED SOLUTION INJECTION For remediation purposes, a portable injection trailer is used to inject a solution of potable water and a chemical oxidant suited to remediate contamination at the site. The injection