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1 ' <br /> M <br /> • 18 July 2002 <br /> AGE-NC Project No 95-0109 <br /> Page 7 of 8 <br /> 4 4 GROUNDWATER SAMPLING PROCEDURES <br /> Ground water sample collection will be performed in accordance with the guidelines established by <br /> the ERD for sampling ground water monitoring wells <br /> 4 4 1 Static Water Level Measurements <br /> Before purging and sampling during ground water monitoring events, static water level will be <br /> measured using an electric water level indicator Water level data will be recorded to the nearest <br /> 0 01-foot from a reference point marked of the top of the PVC well casing Water level and the time <br /> of the measurement will be recorded on a field log Before and after each use, the measurement <br /> device will be rinsed with water <br /> 4 4 2 Well Evacuation <br /> Subsequent to measurement of depth to water and prior to sampling, the well will be purged using <br /> a submersible pump or a disposable bailer to ensure that the sample is representative of the <br /> formation,rather than water standing In the well casing The well will be purged until 1)a minimum <br /> of three casing-water volumes has been removed from the well, and/or 2)the field-measured ground <br /> water parameters have stabilized However, If a well is purged dry prior to evacuating three casing- <br /> water volumes, a ground water sample will be collected following 80 percent recovery of ground <br /> water within the well or within 1 hour of well evacuation <br /> 4 4 3 Sample Withdrawal <br /> Water samples will be collected from the monitoring well using a 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 minimized Sample containers will <br /> be filled using the appropriate disposable sampling attachment which allows controlled flow out of <br /> the bottom of the bailer by lifting the check valve <br /> 4 4 4 Sample Handling <br /> Ground water samples will he collected Into laboratory-supplied containers Ground water samples <br /> for TPH-g, BTEX, fuel additives and volatile organic analysis will be collected Into 40-m1 <br /> EPA-approved VOA vials containing 0 5 ml HCl as a sample preservative Following collection,the <br /> samples will be labeled placed on Ice and kept In a cooler until delivered to the laboratory for <br /> Advanced GeoEnvironmental,Inc <br /> s ` <br />