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21 July 1999 <br /> AGE-NC Project No. 99-0604 <br /> Page 5 of 6 <br /> 3.3. BORING ABANDONMENT <br /> The soil boring will be permanently sealed to prevent vertical migration of potential contaminants <br /> by backfilling with bentonite or cement-bentonite slurry from the total depth to surface grade. The <br /> PHS-EHD will be notified for grout inspection at least 48 hours prior to grout emplacement. <br /> 3.4. GROUNDWATER SAMPLING PROCEDURES <br /> Groundwater sample collection will be performed in accordance with pertinent applicable sampling <br /> protocols, details of which are presented below. <br /> 3.4.1. Static Water Level Measurements <br /> Before sampling and during groundwater monitoring,static water level in the wells will be measured <br /> using an electric water level indicator.Water level data will be recorded to the nearest 0.01 foot from <br /> the surveyed reference point marked of the top of the PVC well casing. Before and after each use, <br /> the measurement device will be washed and rinsed with water. <br /> 3.4.2. 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 of water standing in the well casing. The well will be purged until: 1) a <br /> minimum of three casing volumes is 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 /> volumes, a ground water sample will be collected following 80 percent recovery of ground water <br /> within the well or within 8-hours of well evacuation. <br /> 3.4.3. Sample Collection <br /> Water samples will be collected from the monitoring well using a disposable polyethylene bailer. <br /> These bailers are disposed ofafter 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 ground water to the atmosphere is minimal. Sample containers will be <br /> filled using the appropriate disposable sampling attachment which allows controlled flow out of the <br /> bottom of the bailer by]I fling up on the check valve. <br /> Advanced GeoEnvironmental,Inc. <br />