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Lined Pit Guide 10 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