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17 January 2003 AGE-NC Project No. 02-0946 Page 9 of 9 on the top of the PVC well casing. Before and after each use,the measurement device will be rinsed with water. 4.5.2. Well Evacuation Subsequent to measurement of depth to water and prior to sampling, the well will be purged using a disposable bailer or a submersible pump to ensure that the sample is representative of the formation,rather than water standing in the well casing.The well will be purged until: 1)a minimum of three casing-water volumes of water is removed from the well; and 2)the field-measured ground water parameters have stabilized. However, if a well is purged dry prior to evacuating three casing volumes, a ground water sample will be collected following 80 percent recovery of ground water level within the well or within 2 hours of well evacuation. 4.5.3. Sample Withdrawal Water samples will be collected from the monitoring well using a disposable polyethylene bailer. These pre-cleaned bailers are disposed of after one use and require no decontaminating, thereby minimizing cross contamination due to sampling devices. Samples will be drawn and collected in such a manner that agitation and exposure of the groundwater to the atmosphere is minimal. Sample containers will be filled using the appropriate disposable sampling attachment which allows controlled flow out of the bottom of the bailer by lifting up on the check valve. 4.5.4. Sample Handling Ground water samples will be collected into laboratory supplied containers. Ground water samples for TPH-g, BTEX and fuel oxygenating compound analyses will be collected into 40-m1 VOA vials containing 0.5 ml of hydrochloric acid as preservative. Ground water samples for TPH-d and TPH-mo will be collected into 1-liter amber bottles with no preservative. Following collection the samples will be placed on ice and kept in a cooler until delivered to the laboratory for analysis. Chain-of-custody protocols will be used to document sample custody transfer from the field to the analytical laboratory. A chain-of-custody form will accompany the samples. 4.6. EQUIPMENT DECONTAMINATION All sampling tools used for sample collection will be thoroughly washed with a solution of Alconox and water and rinsed with clean water prior to use. All down-hole drilling and sampling equipment will be pressure washed prior to starting each boring. Advanced Get)EnYICOnitielltal.Inc.