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plugged with a silicone stopper. The sample should be the following data is recorded:air flow,temperature,and
<br /> placed in a non-refrigerated,dry cooler with sufficient packing pressure at collection ports and gauges.
<br /> to eliminate breakage during transport. Cooling samples will
<br /> cause condensation of moisture,thereby distorting laboratory The sampling equipment consists of a sterilized,gas-tight,
<br /> analysis. "Vaca-Sampler"stainless steel canister,and 1/4-inch-
<br /> diameter polyethylene tubing approximately 2 feet in length.
<br /> For quality control purposes,a duplicate air sample should
<br /> be collected from each port. This sample is put on hold at The sampling ports are brass connections fitted with silicone
<br /> the laboratory pending initial analysis. septa and threaded into a tapped hole in the system piping.
<br /> The sampling procedure requires one end of the tubing to be
<br /> Vapor samples are subject to very limited holding times, slipped over the sampling port and the other end over the
<br /> typically 48 hours. Thus,care must taken to avoid delays in canister nozzle to acquire an air-tight connection. The
<br /> submittal of vapor samples to the laboratory. In the event the actuator on top of the canister is depressed for 10 seconds.
<br /> vapor samples cannot be submitted to the analytical At the end of the 10 seconds,the canister is disconnected
<br /> laboratory on the same day they are collected,they are to be from the tubing and the tubing is disconnected from the
<br /> temporarily stored in the dry,non-refrigerated,packed cooler sampling port. Immediately following the sample collection,
<br /> until the very first opportunity for submittal well within the complete sampling information is recorded on the label on
<br /> required holding time,taking into account the time needed for the air sampling canister(e.g.,sample ID,date,time,
<br /> shipment to and receipt by the laboratory. location,and temperature). The sample is placed in a non-
<br /> refrigerated,dry cooler with sufficient packing to ensure
<br /> SOP-11 against damage during transport. Cooling samples will
<br /> VAPOR SAMPLING:CANISTER SAMPLING TECHNIQUE cause condensation of any moisture within the air sample,
<br /> thereby distorting laboratory analysis.
<br /> Prior to vapor sampling,the vacuum system must reach a
<br /> stabilized air flow(cubic feet per minute)for approximately 15
<br /> minutes. Prior to the actual collection of the vapor sample,
<br /> For quality control purposes,a duplicate vapor sample case,this is the depth-to-water(DTW)indication and the
<br /> should be collected from each sampling port. This sample is DTW measurement is made accordingly. The steady tone
<br /> then put on hold at the laboratory pending the initial analysis. indicates floating liquid hydrocarbons(FLH). In this case,the
<br /> To minimize the potential for cross-contamination between probe is slowly raised until the steady tone ceases. This is
<br /> vapor samples,the polyethylene tubing,if not sample the depth-to-product(DTP)indication and the DTP
<br /> dedicated,is thoroughly cleaned and rinsed. measurement is made accordingly.
<br /> Vapor samples are subject to very limited holding times, The process of lowering and raising the probe must be
<br /> typically 48 hours. Thus,care must taken to avoid delays in repeated several times to ensure accurate measurements.
<br /> submittal of vapor samples to the laboratory. In the event the The DTW and DTP measurements are recorded on the
<br /> vapor samples cannot be submitted to the analytical liquid-level data sheet. When FLH are indicated by the
<br /> laboratory on the same day they are collected,they are to be probe's response,a product bailer is lowered partially
<br /> temporarily stored in the dry,non-refrigerated,packed cooler through the FLH-water interface to confirm the FLH on the
<br /> until the very first opportunity for submittal well within the water surface and as further indication of the FLH thickness,
<br /> required holding time,taking into account the time needed for particularly in cases where the FLH layer is quite thin. This
<br /> shipment to and receipt by the laboratory. measurement is recorded on the data sheet as"FLH
<br /> thickness."
<br /> SOP-12
<br /> MEASURING LIQUID LEVELS USING WATER LEVEL In order to avoid cross-contamination of wells during the
<br /> METER OR INTERFACE PROBE liquid-level measurement process,wells are measured in the
<br /> order of"clean"to"dirty"(where such information is
<br /> Field equipment used for liquid-level gauging typically available). In addition,all measurement equipment is
<br /> includes the measuring instrument(water-level meter or cleaned with solution and thoroughly rinsed with deionized
<br /> interface probe)and product bailer(s). The field kit also water before use,between measurements in respective
<br /> includes cleaning supplies(buckets,solution,spray bottles, wells,and at the completion of the day's use.
<br /> and deionized water)to be used in cleaning the equipment
<br /> between wells. SOP-13
<br /> SOIL VAPOR SAMPLING:"TEDLAR"BAG SAMPLING
<br /> Prior to measurement,the instrument tip is lowered into the TECHNIQUE
<br /> well until it touches bottom. Using the previously established
<br /> top-of-casing or top-of-box(i.e.,wellhead vault)point,the The sampling equipment consists of a TedlarTm bag
<br /> probe cord(or halyard)is marked and a measuring tape (available in 1,3,5,and 10 liter sizes),a diaphragm pump,
<br /> (graduated in hundredths of a foot)is used to determine the and 3/16-inch-diameter polyethylene tubing(approximately 1
<br /> distance between the probe end and the marking on the foot long).The Tedlarl" bag should be fitted with an integral
<br /> cord. This measurement is then recorded on the liquid-level valve for filling and sealing the bag after sampling.The
<br /> data sheet as the"Measured Total Depth"of the well. diaphragm pump inlet and outlet are fitted with 3/16-inch
<br /> hose barbs for attaching the sample tubing.Prior to vapor
<br /> When necessary in using the interface probe to measure sampling,the soil vapor source(vapor screen,vapor
<br /> liquid levels,the probe is first electrically grounded to either extraction well or manifold,etc.)must be isolated for
<br /> the metal stove pipe or another metal object nearby. When sampling.A sample label with the sample number and date
<br /> no ground is available,reproducible measurements can be and time of sample collection is prepared and placed on the
<br /> obtained by clipping the ground lead to the handle of the Tedlar"I bag.
<br /> interface probe case.
<br /> If the sample is being collected from an operating vapor
<br /> The probe tip is then lowered into the well and submerged in extraction system,the target vapor manifolds must be set up
<br /> the groundwater. An oscillating(beeping)tone indicates the with sample ports that can be isolated without interrupting
<br /> probe is in water. The probe is slowly raised until either the system operation. Prior to the actual collection of the vapor
<br /> oscillating tone ceases or becomes a steady tone. In either sample,source data is recorded:air flow,temperature,and
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