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k'q KLEINFELDER <br /> File No. 20-4054-01.1301 <br /> May 1, 1997 <br /> B-3.2 Monitoring Well Development <br /> The wells are developed to reduce the effects of drilling on the formation and to increase the <br /> effective hydraulic radius of the well. <br /> Monitoring wells are generally developed 24 to 48 hours after installation to allow the grout to set. <br /> Each well is first sampled with a clear acrylic bailer to visually inspect for hydrocarbon layer or <br /> sheen. If no product layer of sheen is observed on the water, the well is developed by surging, <br /> pumping, or bailing. Surging along the screened interval of the well is performed to draw the <br /> sediment from the formation into the filter pack and the well and to set the sand pack. The <br /> sediment-laden water is purged from the well at a rate of between 0.75 to 10 gallons per minute <br /> (gpm) depending on recharge rate and casing size. Development continues until the discharge runs <br /> relatively clear of fines. Approximately 5 to 10 well volumes generally are removed from each <br /> monitoring well. Discharge water is stored in 55-gallon drums and left on site for later discharge or <br /> disposal by the client, depending on laboratory results. <br /> B-3.3 Equipment Decontamination <br /> To reduce the potential for cross-contamination between wells, developing equipment is washed in <br /> a trisodium phosphate or lab grade detergent solution and rinsed in distilled water or steam cleaned <br /> prior to use in the next monitoring well. <br /> B-3.4 Well Survey <br /> The locations of soil borings and monitoring wells and the elevation of the top of the PVC casings <br /> will be surveyed and tied into permanent markers, if readily available. Survey accuracy is 0.1 foot <br /> for the "x" and "y" coordinates and 0.01 foot for the "z" coordinate. The depth to static <br /> groundwater is measured from a set location at the top of the PVC casing. The depth of water is <br /> then subtracted from the elevation of the top of the well casing to provide a groundwater elevation <br /> for each monitoring well location. <br /> 20-4054-01.E01-G0112017P036 Page B-4 01997,Kleinfelder,Inc. <br />