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1 <br />' GROUNDWATER MONITORING WELL INSTALLATION WORKPLAN <br /> OCTOBER, 1994 <br />' 2.6 Installation of Monitoring Wells <br /> Three groundwater monitoring wells will be constructed in soil bonngs as shown on Figure 2 <br /> The wells will consist of 4-inch, flush threaded, schedule 40 PVC slotted and blank casing A <br /> threaded end cap will be placed at the bottom of the PVC which will then be set through the <br /> auger <br />' The screened PVC casing will consist of 0 02-inch machine-cut slots Number 2 sand (or <br /> equivalent) will be poured down the auger while removing approximately 2-feet of auger at a <br />' time The filter pack will be placed 2-feet above the screened interval Three feet of bentonite <br /> pellets will be poured through the augers to form an annular seal A cement mixture will be used <br /> to fill the annular space to one foot below grade Traffic-rated, flush-mounted well boxes will be <br />' installed at a height of approximately 1-inch above grade to minimize the potential for surface <br /> runoff entering the well <br />' Park proposes to place the slotted interval of the well casing no greater than 15-feet below the <br /> static groundwater level Park requests to deviate from the state guidelines to extend the <br /> screened interval 15 or 25-feet above the groundwater level, depending on the soil conditions <br /> encountered during drilling This would allow the wells to be used for groundwater monitoring <br /> and to be potentially used for vapor extraction remediation of the vadose zone and capillary <br /> fringe <br /> 2.7 Well Development <br />' Each groundwater monitoring well will be developed using a surge block for a least 20 minutes, <br /> and then purged of at least three well volumes of groundwater During purging, values of pH, <br />' conductivity and temperature will be monitored and recorded The well will be allowed to stand <br /> for a sufficient period of time for the groundwater to equilibrate within 80% of static groundwater <br /> level prior to sampling <br /> 2.8 Groundwater Sampling <br />' Groundwater samples will be collected after the well has sufficiently equilibrated static <br /> groundwater levels In the event that the well are not sampled within 24-hours of well <br /> development and purging, each well will again be purged with a bladder or submersible pump <br /> ' until at least three well volumes have been removed Groundwater samples will be collected using <br /> a Teflon or new disposable bailer and placed in a cooler at 4 degrees centigrade or less and <br /> transported to a laboratory under proper COC documentation <br /> 1 <br />