Laserfiche WebLink
tir ... <br /> 26 July 2002 <br /> AGE-NC Project No. 97-0326 <br /> Page 9 of 10 <br /> 4.4.1. Static Water Level Measurements <br /> Prior to all ground water purging and sampling,the static water level 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 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 until: <br /> 1)a minimum of three casing-water volumes is removed from the well;and/or 2)the field-measured <br /> ground waterparameters have stabilized.However,if the well is purged dry prior to evacuating three <br /> casing-water volumes, a ground water sample will be collected following 80 percent recovery of <br /> ground water within the well or within 8 hours of well evacuation. <br /> Single-level monitoring well purge procedures are described in the AGE-prepared Monitoring Well <br /> Installation Work Plan - July 1998. Multi-level monitoring wells will be purged by inserting a <br /> 3/8-inch outer diameter polyethylene hose equipped with a ball-valve water tip (lift bailer) through <br /> the selected well chamber into the specific water-charged screened interval and oscillating the tube <br /> vertically to lift the water up and out. <br /> 4.4.3. Sample Withdrawal <br /> Water samples will be collected from the wells utilizing the same bailer used for purging.The bailers <br /> are disposed of after one use and require no decontaminating, thereby minimizing cross <br /> contamination due to sampling devices. <br /> 4.4.4. Sample Handling and Analysis <br /> Ground water samples will be collected into laboratory-supplied 40-m1 volatile organic analysis <br /> (VOA)vials containing 0.5 ml of hydrochloric acid as preservative. Care will be taken to ensure that <br /> visible air bubbles are not present in the vials after filling and capping. Following collection the <br /> samples will be appropriately labeled, placed on ice and kept in a cooler until delivered to a DHS- <br /> certified analytical laboratory for analysis. Chain-of-custody protocols will be used to document <br /> sample custody transfer from the field to a DHS-certified laboratory; a chain-of-custody form will <br /> accompany the samples. <br /> Advanced GeoEnvironmental,lne. <br />