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22 September 2009 <br /> AGE-NC Project No. 09-1692 <br /> Page 10 of 11 <br /> 5.4. WELL DEVELOPMENT AND ELEVATION SURVEY <br /> The wells will be developed at least 48 hours after installation to allow for the grout to set. <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 /> Following completion of the monitoring wells,well elevations and locations will be surveyed by a <br /> California-licensed surveyor relative to the City of Stockton elevation benchmark. <br /> 5.5. QUARTERLY GROUNDWATER SAMPLING PROCEDURES <br /> Ground water sample collection will be performed in accordance with the CVRWQCB guidelines <br /> and general industry standards. <br /> 5.5.1. 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 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 /> 5.5.2. Well Evacuation <br /> Subsequent to measurement of depth to water and prior to sampling, the well will be purged using <br /> a Waterra inertia pump, submersible pump or a disposable bailer, to ensure that the sample is <br /> representative of the formation,rather than water standing in the well casing.The well will be purged <br /> until: 1)a minimum of three casing volumes is removed from the well; and/or 2)the field-measured <br /> ground water parameters have stabilized.However,if a well is purged dry prior to evacuating three <br /> casing volumes, a ground water sample will be collected following 80 percent recovery of ground <br /> water within the well or within 8-hours of well evacuation. <br /> Purge water,free-product,and decontamination water generated during the ground water sampling <br /> activities will be contained in DOT-approved drums which will be appropriately labeled for storage. <br /> Advanced GeoEnvironmental,Inc. <br />