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19 March 1999 <br /> AGE-NC Project No. 98-0471 <br /> Page 11 of 12 <br /> will be recorded to the nearest 0.01 foot from a reference point marked of the top of the PVC well <br /> casing. Before and after each use, the measurement device will be washed in an Alconox solution <br /> and rinsed with water. <br /> 4.3.2. Well Evacuation <br /> Subsequent to measurement of depth to water and prior to sampling, the well will be purged using <br /> a disposable bailer to ensure that the ground water sample is representative of the formation, rather <br /> than water standing in the well casing. The well will be purged until: 1) a minimum of three casing <br /> volumes of water is removed from the well; and/or 2) the field-measured ground water parameters <br /> have stabilized. However, if a well is purged dry prior to evacuating three casing volumes, a ground <br /> water sample will be collected following 80 percent recovery of ground water level within the well <br /> or within 8-hours of well evacuation. <br /> Purge water, free-product, and decontamination water generated during the ground water sampling <br /> activities will be contained in DOT-approved drums which will be appropriately labeled for storage. <br /> Drums containing purge water will be stored on-site pending appropriate removal and disposal. <br /> 4.3.3. Sample Withdrawal <br /> Water samples will be collected from the monitoring wells using disposable polyethylene bailer. <br /> These bailers are disposed of after one use and require no decontaminating,thereby minimizing cross <br /> contamination due to sampling devices. Samples will be drawn and collected in such a manner that <br /> agitation and exposure of the groundwater to the atmosphere is minimal. Sample containers will be <br /> filled using the appropriate disposable sampling attachment which allows controlled flow out of the <br /> bottom of the bailer by lifting up on the check valve. <br /> 4.3.4. Sample Handling <br /> Ground water samples will be collected into laboratory supplied containers. Ground water samples <br /> to be analyzed for TPH-g,BTEX and MTBE oxygenates analyses will be collected into 40-m1 VOA <br /> vials,containing 0.5-m1 of hydrochloric acid 18%as preservative. Following collection the samples <br /> will be placed on ice and kept in a cooler until delivered to the laboratory for analysis. Chain-of- <br /> custody protocols will be used to document sample custody transfer from the field to the analytical <br /> laboratory. A chain-of-custody form will accompany the samples. <br /> Advanced GeoEnvironmental,Inc. <br />