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<br /> and deionized water) to be used in cleaning the equipment If the sample is being collected from an operating vapor
<br /> 1 between wells. extraction system, the target vapor manifolds must be set up
<br /> With sample ports that can be isolated without interrupting
<br /> Prior to measurement, the instrument tip is lowered into the system operation. Prior to the actual collection of the vapor
<br /> well until it touches bottom. Using the previously established sample, source data is recorded: air flow, temperature, and
<br /> top-of-casing or top-of-box (i.e. , wellhead vault) point, the pressure; or, well identification number and depth interval of
<br /> probe cord (or halyard) is marked and a measuring tape screen.
<br /> (graduated in hundredths of a foot) is used to determine the
<br /> distance between the probe end and the marking on the Typical sampling ports consist of a 1 /4 —inch ball valve fitted
<br /> cord. This measurement Is then recorded on the liquid-level with a 3/16-inch hose barb to form a slip stream from the
<br /> - data sheet as the "Measured Total Depth" of the well. sample source.
<br /> -� When necessary in using the interface probe to measure The sampling procedure requires one end of the tubing be
<br /> liquid levels, the probe is first electrically grounded to either slipped over the sample port hose barb and the other end
<br /> the metal stove pipe or another metal object nearby. When over the diaphragm pump inlet hose barb to form an air-fight
<br /> no ground is available, reproducible measurements can be connection. The sampling pump is then started and the
<br /> -_ obtained by clipping the ground lead to the handle of the pump is purged for one minute with the vapor to be sampled.
<br /> interface probe case.
<br /> Following purging, the discharge of the pump is then
<br /> - The probe tip is then lowered into the well and submerged in connected to the "Tedlar' bag using a section of 3/16-inch
<br /> the groundwater. An oscillating (beeping) tone indicates the tubing. The pump is restarted and the bag is opened and
<br /> I- - probe is in water. The probe is slowly raised until either the allowed to fill to approximately 3/4 of its capacity. Caution
<br /> oscillating tone ceases or becomes a steady tone. In either should be taken not to overfill the sampling bag. The sample
<br /> case, this is the depth-to-water (DTW) indication and the is placed in a non-refrigerated dry cooler with sufficient
<br /> DTW measurement is made accordingly. The steady tone packing to prevent damage during transport. Cooling
<br /> indicates floating liquid hydrocarbons (FLH). In this case, samples will cause condensation of moisture within the
<br /> the probe is slowly raised until the steady tone ceases. This sample, thereby distorting the laboratory analysis.
<br /> is the depth-to-product (DTP) indication and the DTP
<br /> measurement is made accordingly. For quality control purposes, a duplicate vapor sample
<br /> should be collected from each sampling port. This sample is
<br /> The process of lowering and raising the probe must be then put on hold at the laboratory pending initial analysis. To
<br /> repeated several times to ensure accurate measurements. ensure quality control and minimize the potential for cross-
<br /> The DTW and DTP measurements are recorded on the contamination pdor to and during sampling, the diaphragm
<br /> liquid-level data sheet. When FLH are indicated by the pump is thoroughly purged for approximately five minutes
<br /> - probe's response, a product bailer is lowered partially with nitrogen or clean air (i.e., compressed clean air). A
<br /> through the FLH-water interface to confirm the FLH on the "blank" sample of the discharged air is captured in a "Tedlar'
<br /> _ ! water surface and as further indication of the FLH thickness, bag at the end of the purging procedure and may be
<br /> particularly in cases where the FLH layer is quite thin. This analyzed to ensure the purging was effective.
<br /> _ measurement is recorded on the data sheet as "FLH
<br /> thickness." To minimize the potential for cross-contamination between
<br /> air samples, the polyethylene tubing, if not sample
<br /> - In order to avoid cross-contamination of wells during the dedicated, is thoroughly cleaned and rinsed.
<br /> liquid-level measurement process, wells are measured in the
<br /> ,- order of "clean" to "dirty" (where such information is Vapor samples are subject to very limited holding times,
<br /> available). In addition, all measurement equipment is typically 48 hours. Thus, care must taken to avoid delays in
<br /> _ . cleaned with solution and thoroughly rinsed with deionized submittal of vapor samples to the laboratory. In the event
<br /> water before use, between measurements in respective the vapor samples cannot be submitted to the analytical
<br /> wells, and at the completion of the day's use. laboratory on the same day they are collected, they are to be
<br /> temporarily stored in the dry, non-refrigerated, packed cooler
<br /> SOP-11 until the very first opportunity for submittal well within the
<br /> SOIL VAPOR SAMPLING: "TEDLAR" BAG SAMPLING required holding time, taking into account the time needed
<br /> TECHNIQUE / REMEDIATION SYSTEM SAMPLING for shipment to and receipt by the laboratory.
<br /> Prior to vapor sampling, the vacuum system must reach a SOP42
<br /> stabilized air flow (cubic feet per minute) for approximately VAPOR SAMPLING: SUMMA CANISTER SAMPLING
<br /> 15 minutes. Prior to the actual collection of the vapor TECHNIQUE
<br /> sample, the following data is recorded: air flow, temperature,
<br /> and pressure at collection ports and gauges. Prior to vapor sampling, the vacuum system must reach a
<br /> stabilized air flow (cubic feet per minute) for approximately
<br /> The sampling equipment consists of a Tedlar"^ bag 15 minutes. Prior to the actual collection of the vapor
<br /> - (available in 1 , 31 5, and 10 liter sizes), a diaphragm pump, sample, the following data is recorded: air flow, temperature,
<br /> and 3/16-inch-diameter polyethylene tubing (approximately 1 and pressure at collection ports and gauges.
<br /> foot long). The TedlarTM bag should be fitted with an integral
<br /> valve for filling and sealing the bag after sampling. The The sampling equipment consists of a sterilized, gas-tight,
<br /> diaphragm pump inlet and outlet are fitted with 3/16-inch "Summa" stainless steel canister (available in one and six
<br /> hose barbs for attaching the sample tubing. Prior to vapor liter volumes), flow meter (if required , obtained and
<br /> sampling, the soil vapor source (vapor screen, vapor calibrated by the laboratory) and 1/4-inch-diameter
<br /> extraction well or manifold, etc.) must be isolated for polyethylene tubing approximately 2 feet in length.
<br /> sampling. A sample label with the sample number and date
<br /> - and time of sample collection is prepared and placed on the The sampling ports are brass connections fitted with silicone
<br /> Tedlar"" bag. septa and threaded into a tapped hole in the system piping.
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