Laserfiche WebLink
8 <br /> shall consist of a sand-cement mixture in accordance with California Department of Water <br /> Resources Well Standards, Bulletin 74-81/Supplement 74-90. <br /> 2. The mixture for the surface, or sanitary, seal shall conform to State standards and local <br /> ordinances for sanitary seals. <br /> 3. The bentonite sealing material shall be a graded chip bentonite with granules ranging <br /> from 1/4 inch to 3/8 inch. An approved product for the bentonite seals is"HOLEPLUG"as <br /> manufactured by the NL Baroid Division of NL Industries, Inc. <br /> B. Well Casing and Screen Material <br /> 1. The 2-inch diameter PVC well casing and well screen for the monitoring well will <br /> be made of ASTM F-480-88A Schedule 40 PVC. The ends of each joint shall be <br /> threaded and couple with O-ring seals. The blank casing will be 2-inch Schedule <br /> 40 PVC, ASTM F480-88a. The well screen shall be fabricated from the same <br /> material as the blank casing. The perforations shall be machine cut horizontal <br /> slots, with openings of 0.030 inch. <br /> 2. The bottom of each PVC casing assembly shall be furnished with PVC threaded, <br /> pointed or rounded end cap of the same schedule and size as the casing and the <br /> same specifications as described herein. <br /> 3. Each casing will be fitted with appropriate centralizers to ensure that the well <br /> casings meet the minimum 2-inch separation distance from the borehole wall <br /> 4. The top of each casing shall be furnished with a watertight and locking security <br /> plug. <br /> C. Gravel Envelope --All gravel or coarse-grained sand for packing shall be hard, water-worn, <br /> and washed clean of silt,fine sand, dirt, and foreign matter(crushed gravel will not be accepted). It <br /> shall be well rounded, graded, and selected. The gravel envelope material is specified to be Silica <br /> Resources Incorporated(SRI -Marysville, CA)sand, or equal. Alternative materials are subject to <br /> the approval of the Engineer. A description and sieve analysis of gravel packing materials to be <br /> delivered to the site must be submitted prior to the use of the material in the Work. The gravel, if <br /> stockpiled at the well site, shall be protected and kept free of foreign matter. <br /> 2.3 TEST HOLE DRILLING AND MONITORING WELL CONSTRUCTION <br /> 2.3.1 MOBILIZATION AND SITE TO SITE MOBILIZATION <br /> A. General <br /> 1. Mobilization to the site shall include acquisition and payment for all necessary permits; <br /> transportation of personnel, equipment, and operating supplies to and from the site <br /> establishment of portable sanitary facilities, preparing a work site sufficient to support <br /> equipment and personnel in a safe and workman-like manner,and other preparatory work <br /> at the site required by the Contractor for his/her operations. <br /> 2. The Contractor shall provide one complete direct rotary drilling unit with shaker, <br /> desanding cones, and containment facilities. The Contractor shall also provide all tools, <br />