Laserfiche WebLink
hKLEINFELDER <br /> A-3.2 Monitoring Well Development <br /> The wells are developed to reduce`.the effects of drilling on the formation and to irâ–ºcrease the <br /> effective hydraulic radius of the we.lL <br /> Monitoring wells are generally developed 24. to 48 hours after installation to allow the grout to <br /> set. Each well is -first sampled with a clear acrylic bailer to visually inspect for hydrocarbon layer <br /> or sheen. 1 C.no product layer of sheen is observed on the water, the well is developed by surging, <br /> pumpi.rig, or baiiing. Surging alone 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 pureed 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 <br /> runs relatively clear of fides. Approximately.5 to 10 well volumes generally are removed :Brom sl <br /> each monitoring wcJl. Discharge ,vater is stored in 55-ballon drums and left on site .For later <br /> discharge or disposal by the client, depending on laboratory results. <br /> A-3.3 Equipment Decontamination <br /> To reduce the potential for cross-contamination between wells, developing equipment is washed <br /> in a trisodium phosphate or lab grade detergent solution and rinsed in distilled water or steam. <br /> cleaned prior to use.in the next.monitoring well. <br /> A-3.4 Well Survu% <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 permai.ient rriarki.rs, if readily available. Survey accuracy is 0.1 foot <br /> for the "x" and "y" coordinates and 0.01 foot for the "r" 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 /> fbr each monitoring well location. <br /> 20-Y[18-124/20181'1,11!20180270 Pagc A-4 <br /> © 1998. IClcinlcldcr. Inc. June IG. 1998 <br />