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' pack, and pumping. Development activities were continued until a minimum of 10 well casing ivolumes of water were purged and field parameter (pH, electrical conductivity, and temperature) ' readings had stabilized. Purge water generated during development activities was contained on-site in an appropriately labeled 55-gallon drum. ' A.S. GROUND WATER SAMPLING PROCEDURES ' Prior to purging and sampling, static water level was measured using an electric water level indicator. Water level data was recorded to the nearest 0.01 foot from a reference point marked on the top of the PVC well casing. Before and after each use,the measurement device was rinsed with ' water. ' A.5.1. Well Evacuation Subsequent to measurement of depth to water and prior to sampling,the well was purged to ensure ' that the sample is representative of the formation, rather than water standing in the well casing. The monitoring well was purged using a two-stage submersible pump. The wells were purged until: 1) a ' minimum of three casing volumes was removed from each well; and 2)field-measured ground water parameters including temperature, electrical conductivity, and pH had stabilized. A ground water sample was collected following 80 percent recovery of ground water within the well. '• Purge water generated during development activities was contained on-site in an appropriately labeled 55-gallon drum. A.5.2. Sample Withdrawal Ground water samples were collected from the monitoring wells using disposable polyethylene bailers. These bailers are disposed of after one use and required no decontaminating, minimizing ' cross contamination due to sampling devices. The samples were drawn and collected in such a manner that agitation and exposure of the groundwater to the atmosphere was minimal. Sample ' containers were filled using the appropriate disposable sampling attachment which allows controlled flow out of the bottom of the bailer. ' A.5.3. Sample Handling ' The ground water samples were collected into laboratory-supplied containers. The ground water samples for TPH-g, BTEX, and fuel oxygenate analyses were collected into 40-m1 VOA vials containing 0.5 ml of hydrochloric acid as preservative. Samples for TPH-d analysis were collected ' into unpreserved 1-liter amber glass container. Following collection the samples were appropriately labeled and placed on ice in a cooler until delivered to the laboratory for analysis. Chain-of-custody protocols were implemented to document sample custody transfer from the field to the analytical Advanced GeoEnvironmenta[,]ne.