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21 March 2003 <br /> AGE-NC Project No. 95-0114 <br /> Page 10 of 11 <br /> 4.4.1. Static Water Level Measurements <br /> Prior to all ground water purging and sampling, static water levels in each well will be measured <br /> using an electric water level indicator.Water level data will be recorded to the nearest 0.01-foot from <br /> a reference point marked on the top of each Teflon well casing. Before and after each use, the <br /> measurement device will be washed with a solution of Alconox and rinsed with clean water. <br /> 4.4.2. Well Evacuation <br /> Subsequent to measurement of depth to water and prior to sampling, each well will be purged by <br /> inserting a 3/8-inch outer diameter polyethylene hose equipped with a ball-valve water tip(lift bailer) <br /> through the selected well chamber into the specific water-charged screened interval and oscillating <br /> the tube vertically to lift the water. The well will be purged until: 1) a minimum of three casing- <br /> water volumes is removed from the well;and/or 2)the field-measured ground water parameters have <br /> stabilized. However, if the well is purged dry prior to evacuating three casing-water volumes, a <br /> ground water sample will be collected following 80 percent recovery of ground water within the well <br /> or within 8 hours of well evacuation. <br /> 4.4.3. Sample Withdrawal <br /> Water samples will be collected from the monitoring well screen using the same lift bailer used for <br /> purging.These bailers consist of 3/8-inch tube and base check-valve and are disposed of after one use <br /> and require no decontaminating, thereby minimizing cross contamination due to sampling devices. <br /> Care will be taken to ensure that visible air bubbles are not present in the vials after filling and <br /> capping. <br /> 4.4.4. Sample Handling <br /> Ground water samples will be collected into laboratory-supplied containers. Ground water samples <br /> will be collected into 40-m1 volatile organic analysis(VOA)vials containing 0.5 ml of hydrochloric <br /> acid as preservative. Following collection the samples will be appropriately labeled, placed on ice <br /> and kept in a cooler until delivered to the laboratory for analysis. Chain-of-custody protocols will <br /> be used to document sample custody transfer from the field to the analytical laboratory.A chain-of- <br /> custody form will accompany the samples. <br /> Advanced GeoEnvironmental,Inc. <br />