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KLEINFELDER <br /> A-3 2 Monitoring Well Development <br /> • The wells are developed to reduce the effects of dulling 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 <br /> to set Each well is first sampled with a clear acrylic bailer to visually inspect for <br /> hydrocarbon layer or sheen if no product layer of sheen is observed on the water, the well <br />' is developed by surging, pumping, or bailing Surging along the screened interval of the <br /> well is performed to draw the sediment from the formation into the filter pack and the well <br /> and to set the sand pack The sediment-laden water is purged from the well at a rate of <br />' between 0 75 to 10 gallons per minute (gpm) depending on recharge rate and casing size <br /> Development continues until the discharge runs relatively clear of fines Approximately 5 <br />' to 10 well volumes generally are removed from each monitoring well Discharge water is <br /> stored in 55-gallon drums and left on site for later discharge or disposal by the client, <br /> depending on laboratory results <br /> A-3.3 Equipment Decontamination <br />' To reduce the potential for crass-contamination between wells, developing equipment is <br /> washed in a trisodium phosphate or lab grade detergent solution and rinsed in distilled water <br /> Mor steam cleaned prior to use in the next monitoring well <br />' A-3.4 Well Survey <br />' The locations of soil borings and monitoring wells and the elevation of the top of the PVC <br /> casings will be surveyed and tied into permanent markers, if readily available Survey <br /> accuracy is 0 1 foot for the "x" and "y" coordinates and 0 01 foot for the "z" coordinate <br />' The depth to static groundwater is measured from a set location at the top of the PVC <br /> casing The depth of water is then subtracted from the elevation of the top of the well <br /> casing to provide a groundwater elevation for each monitoring well location <br /> A-4 GROUNDWATER <br /> A-4.1 Water Level Measurements <br />' Water level measurements are made in the wells prior to purging and sampling the wells <br /> Measurement protocol is as follows <br /> 1 The wells are opened and allowed to equilibrate with the atmosphere <br /> GH and 7EI94 Page ry of v <br />' Copyright 1994 Klernfelder, Inc <br />