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w <br /> 19 July 2005 <br /> AGE-NC Project No. 95-0135 <br /> Page 8 of 9 <br /> t". <br /> bailer to remove the major portion of fine-grained sediment from inside the well, surging to flush <br /> out or draw in sediment from the filter pack,and additional ground water evacuation with a Waterra <br /> inertia pump to finish the removal of fine-grained sediment. Developmental purging activities will <br /> be continued until field parameters(pH,electrical conductivity,and temperature)have stabilized and <br /> purged water is visually sediment-free. <br /> 4.4. GROUNDWATER SAMPLING PROCEDURES <br /> Ground water sample collection will be performed in accordance CVRWQCB guidelines and the <br /> L. EHD's Recommended Groundwater Sampling Guidelines, dated 15 February 1995. <br /> t <br /> 6W 4.4.1. Static Water Level Measurements <br /> t Before purging and sampling during ground water monitoring events, static water levels 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 at the top of the PVC well casing.Before and after each use, <br /> the electric water level indicator will be washed in an Alconox solution and rinsed with water. <br /> 4.4.2. Well Evacuation <br /> After measuring the depth to water and prior to sampling, the well will be purged using a <br /> ;,e, submersible pump 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 /> c 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 /> w <br /> Purge water and decontamination water generated during the ground water sampling activities will <br /> be contained in Department of Transportation (DOT)-approved 55-gallon drums, which will be <br /> appropriately labeled for storage. Drums containing purge water will be stored on-site pending <br /> appropriate removal and disposal. <br /> LM <br /> 4.4.3. Sample Withdrawal <br /> Water samples will be collected from the monitoring wells using a disposable polyethylene bailer <br /> 1i' Advanced GeoEnvironmental,Inc. <br />