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19 March 2004 <br /> AGE-NC Project No. 02-0886 <br /> Page 7of8 <br /> grouting inspection will be scheduled with EHD personnel.Borings not completed as ground water <br /> monitoring wells shall be grouted under the same protocol above. <br /> Following completion of the monitoring wells,well elevations and locations will be surveyed by a <br /> California-licensed surveyor relative to a San Joaquin County elevation benchmark. <br /> 4.3. WELL DEVELOPMENT <br /> Development of the proposed wells will consist of a combination of bailing with a stainless steel <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(purging)with <br /> a Waterra bailing pump to finish the removal of fine-grained sediment. Developmental purging <br /> activities will be continued until field parameter (pH, electrical conductivity, and temperature) <br /> readings have stabilized and purged water is visually sediment-free. <br /> 4.4. GROUND WATER SAMPLING PROCEDURES <br /> Ground water sample collection will be performed in accordance with CRWQCB guidelines (Tri- <br /> Regional Water Quality Control Board Recommendations for Preliminary Investigations and <br /> Evaluation of Underground Storage Tanks) sampling protocols. <br /> 4.4.1. Static Water Level Measurements <br /> Before sampling and during groundwater monitoring, static water level will be measured using an <br /> electric water level indicator. Water level data will be recorded to the nearest 0.01-foot from a <br /> reference point marked of the top of the PVC well casing. The total well casing depth will also be <br /> measured. Before and after each use, the measurement device will be decontaminated. <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 /> an inertia pump,submersible pump or a disposable bailer,to ensure that the sample is representative <br /> of the formation, rather than water standing in the well casing. The well will be purged until: 1) a <br /> minimum of three casing-water volumes has been removed from the well; and/or 2) the field- <br /> measured ground water parameters,pH,temperature and conductivity have stabilized. However,if <br /> a well is purged dry prior to evacuating three casing volumes, a ground water sample will be <br /> collected following 80 percent recovery of ground water within the well or after a minimum of one <br /> Advanced GeoEnvironmental,Inc. <br />