Laserfiche WebLink
09 February 2004 <br /> AGE-NC Project No. 98-0452 <br /> Page 7 of 8 <br /> 4.4. GROUNDWATER SAMPLING PROCEDURES <br /> Ground water sample collection will be performed in accordance with the EHD's Recommended <br /> Groundwater Sampling Guidelines, dated 15 February 1995- <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. Before and after each <br /> use, the electric oil/water level indicator will be washed in an Alconox solution and rinsed with <br /> 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 disposable bailer to ensure that the ground water sample is representative of the formation, rather <br /> than water standing in the well casing. The well will be purged until: 1) a minimum of three casing <br /> volumes is removed from the well; and/or 2) the field-measured ground water parameters pH, <br /> temperature and electrical conductivity have stabilized. However, if a well is purged dry prior to <br /> evacuating three casing volumes, a ground water sample will be collected following 80 percent <br /> recovery of ground water level within the well or within 8-hours of well evacuation. <br /> Purge water and decontamination water generated during the ground water sampling activities will <br /> be contained in DOT-approved drums which will be appropriately labeled for storage. Drums <br /> containing purge water will be stored on-site pending appropriate removal and disposal. <br /> 4.4.3. Sample Withdrawal <br /> Water samples will be collected from the monitoringwells using dedicated,disposable polyethylene <br /> hailers. These bailers are disposed of after one use and require no decontaminating, thereby <br /> minimizing cross contamination due to sampling devices. Samples will be drawn and collected in <br /> such a manner that agitation and exposure of the ground water to the atmosphere is minimal. Sample <br /> containers will be filled using the appropriate disposable sampling attachment which allows <br /> controlled flow out of the bottom of the bailer by lifting up on the check valve. <br /> Advanced Geo E;nviromnental.Inc. <br />