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� 4 <br /> Monitoring Well Installation <br /> ' Monitoringwells m <br /> in cemented non-cobble matrix will be completed by installing 2- <br /> inch-diameter schedule 40 polyvinyl chloride (PVC) casing in a 6- to 8-inch <br /> borehole The 2-inch-diameter flush-threaded casing is generally used for wells <br /> dedicated for groundwater monitoring purposes or a 1-inch "prepacked" pvc casing <br /> may be placed in a 4-inch diameter DPT bore hole using the DPT hollow stem and <br /> head The screened sections of casing are factory machine slotted with 0010- or <br /> 0 02-inch openings They will be installed approximately 5 feet above and 15 feet <br /> ' below first-encountered water level The screen length is reduced if an aquitard with <br /> a minimum thickness of 5 feet is encountered If an aquitard is encountered the well <br /> is usually terminated 1 to 2 feet into the aquitard Effort is made to not screen <br /> across two aquifers The screened interval will allow for seasonal fluctuation in <br /> water level and for monitoring floating product A filter pack of appropriate clean <br /> graded RMC Pacific 0130 or 2112 Monterey sand will be placed in the annular space <br /> between the PVC casing and the borehole wall Sand will be added to the borehole <br /> through the hollow stem of the augers to provide a uniform filter pack around the <br /> casing and to stabilize the borehole The sand pack will be placed to a maximum of <br /> ' 2-feet above the screens followed by a minimum 2-feet seal consisting of bentonite <br /> pellets <br /> Cement grout containing 5 percent bentonite or concrete will be placed above the <br /> bentonite seal to the ground surface Monitoring well will be protected from traffic <br /> by concrete pipe or a concrete traffic-rated vault box will be installed over the <br /> ' monitoring well(s) A watertight locking cap will be installed over the top of the well <br /> casing Reference elevations for each monitoring well will be surveyed when more <br /> than two wells will be located on site Depth to water surface in direct push <br /> ' technology holes will be measured and recorded after level has stabilized PVC <br /> pipe will be left in holes until removed prior to grouting Monitoring well elevations <br /> will be surveyed by a State of California registered civil engineer or licensed <br /> surveyor or a subcontractor to the nearest 0 01 foot relative to mean sea level or a <br /> site datum <br /> t Exploratory boring logs and well construction details will be prepared for the final <br /> written report <br /> ' Well installation will be carried out by a properly licensed contractor A permit for <br /> the well will be required from San Joaquin County Health Department <br /> 1 <br /> B -4 <br />