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The sampling equipment consists of a"Tedlar"bag(available The probe tip is then lowered into the well and submerged in in 1,3,5,and 10 liter sizes),a diaphragm pump,and 1144nch- the groundwater. An oscillating(beeping)tone indicates the diameter polyethylene tubing(appro)amately 1 foot long). probe is in water. The probe is slowly raised until ether the oscillating tone ceases or becomes a steady tone. In either The sampling ports are brass connections,fitted with a silicone case,this Is the depth-to-water(DTW)indication and the DTW septa,and threaded into a tapped hole in the system piping. measurement is made accordingly. The steady tone indicates The sampling procedure requires one end of the tubing be floating liquid hydrocarbons(FLH). In this case,the probe is slipped over the sampling port and the other end over the slowly raised until the steady tone ceases. This is the depth-to- diaphragm pump to acquire an airdigM connection. The product(DTP)indication and the DTP measurement is made sampling pump is purged for 1 minute with the extracted vapor accordingly. to be sampled. Following purging,the discharge of the pump is then diverted through a two-way valve into the"Tedlar"bag, The process of lowering and raising the probe must be Mich should be filled to 314 of volume capacity. Caution repeated several times to ensure accurate measurements. The should be taken not to overfill the sampling bag. The sample is DTW and DTP measurements are recorded on the liquid-level placed in a non-refrigerated dry cooler with sufficient packing to data sheet. When FLH are indicated by the probe's response, eliminated damage during transport. Cooling samples will a product baiter is lowered partially through the FLH-water cause condensation of moisture within the sample,thereby interface to confirm the FLH on the water surface and as distorting laboratory analysis. further indication of the FLH thickness,particularly in cases where the FLH layer is quite thin. This measurement is For quality control purposes,a duplicate vapor sample should recorded on the data sheet as"FLH thickness," be collected from each sampling port This sample is then put on hold at the laboratory pending initial analysis. To ensure In order to avoid cross-contamination of wells during the liquid- quality control and minimize the potential for cross- level measurement process,wells are measured in the order of contamination prior to and during sampling,the diaphragm "clean"to"dirty"(where such information is available). In pump is thoroughly purged for approbmately 5 minutes with addition,all measurement equipment is cleaned with solution nitrogen or clean air(i.e.,compressed clean air), A"blame' and thoroughly rinsed with deionized water before use,between sample of the discharged air is raptured in a'Tedlar"bag at measurements in respective wells,and at the completion of the the end of the purging procedure and may be analyzed to day's use. ensure the purging was effective. To minimize the potential for cross-contamination between air samples,the polyethylene tubing,if not sample dedicated,is thoroughly cleaned and rinsed. Vapor samples are subject to very limited holding times, typically 48 hours. Thus,care must taken to avoid delays in '1 submittal of vapor samples to the laboratory. In the event the vapor samples cannot be submitted to the analytical laboratory on the same day they are collected,they are to be temporarily erated packed cooler until the very stored in the dry,non-refig ,p first opportunity for submittal welt within the required holding time,taWng into account the time needed for shipment to and receipt by the laboratory. SOP-1 2 MEASURING LIQUID LEVELS USING WATER LEVEL METER OR INTERFACE PROBE Field equipment used for liquid-level gauging typically includes the measuring instrument(water-level meter or interface probe) and product bailer(s). The field kit also includes cleaning supplies(buckets,solution,spray bottles,and deionized water) to be used in cleaning the equipment between wells. Prior to measurement,the instrument tip is lowered into the well until it touches bottom. Using the previously established top-of- casing or top-of-box(i.e.,wellhead vaulty point,the probe cord (or halyard)is marked and a measuring tape(graduated in hundredths of a foot)is used to determine the distance between the probe end and the marking on the cord. This measurement is then recorded on the liquid-level data sheet as the"Measured Total Depth"of the well. When necessary in using the Interface probe to measure liquid levels,the probe is first electrically grounded to either the metal stove pipe or another metal object nearby. When no ground is available,reproducible measurements can be obtained by clipping the ground lead to the handle of the interface probe case. Page 2-SOP Operation 8 Maintenance