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Lined Pit Guide l0 September 2000 <br /> first excavating a trench with a flat floor and sloping sides around the perimeter of the reservoir at the <br /> midpoint of the wedge of soil liner fill that will be installed. Trench excavation continues until <br /> impermeable material is penetrated to the depth listed in the specifications. The keyway is backfilled <br /> with soil liner fill that is compacted in accordance with the specifications. <br /> Soil Liner Cover Fill <br /> The design should describe the materials that will be used to bury the soil liner and the depth of burial <br /> to prevent desiccation, freeze-thaw effects, and erosion. Typically, the wedge of soil liner fill may by <br /> covered by several feet of random fill, and the reservoir perimeter protected from wave erosion by a <br /> layer of pit run gravel or riprap depending on the size of the water surface and the anticipated wave <br /> generation. <br /> Specifications <br /> The Division of Minerals and Geology does not require that Applicants provide the complete set of <br /> technical specifications for a soil liner project. However, certain elements of the specifications should <br /> be incorporated into the reclamation permit to become eligible for the lower bond under the regulated <br /> construction option. These elements are outlined in the following list of typical examples: <br /> Submittals -Provide a basic earthwork operations plan and schedule for the installation of the soil <br /> liner and the soil liner cover fill. Include a description of the equipment and quality control <br /> procedures to be used, including lift thickness control, composite material preparation, and methods <br /> for moisture conditioning. <br /> • Materials—Soil liner and soil liner cover fill shall be free of organic matter, debris, frozen material, <br /> and other deleterious.materials. Soil liner fill shall be excavated from approved borrow areas and <br /> conform to the following (example) specification: <br /> U.S. Standard Percent Passing <br /> Sieve Size by Dry Weight <br /> 3/4-inch 100 <br /> 3/8-inch 70-100 <br /> No. 4 50-100 <br /> No. 40 20-50 <br /> No. 200 20-50 <br /> Plasticity Index 10 minimum <br /> • Excavations —Excavations shall be graded and properly maintained to provide adequate drainage at <br /> all times. Work shall be suspended when the site is overly wet, muddy, or otherwise unsuitable for <br /> proper maintenance. In excavations where soil liner fill is to be placed on slopes steeper than <br />