Laserfiche WebLink
Monitoring Well Installation <br /> ' Monitoring wells were completed by installing 2-inch-diameter Schedule 40 <br /> polyvinyl chloride {PVC} casing. The 2-inch-diameter flush-threaded casing <br /> is generally used for wells dedicated for ground-water monitoring purposes. <br /> The wells were screened from approximately 76 to 90 feet below the ground <br /> surface. A filter pack of graded sand was placed in the annular space <br /> ' between the PVC casing and the bore hole wall. Sand was added to the <br /> bore holes either through the hollow stem of the augers or down the open <br /> bore hole to provide a uniform filter pack around the casing. The sand pack <br /> ' was placed to a maximum of 3 feet above the screens followed by a <br /> minimum 1-foot seal consisting of hydrated bentonite pellets. <br /> Cement grout containing 5 percent bentonite was placed above the <br /> ' bentonite seal to the ground surface. A traffic-rated vault box and locking <br /> well cap were installed over each monitoring well to protect each well and <br /> ' prevent unauthorized access. Reference elevations for each monitoring well <br /> were surveyed by Yolo Engineers and Surveyors to the nearest 0.01 foot <br /> relative to mean sea level based on city of Stockton benchmark B.B.1-11. <br /> 1 <br /> pj010f9010f900020.1 ag B - 2 Rev. 0 December 15, 1992 <br />