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<br />Memo to Erica Crosbv 5 March 22 X000 <br />materials will be managed to ensure adequate compaction for stability. The Division has the following <br />questions or concerns relative to the proposed dike: <br />• The applicant proposes to use excess topsoil stripped from the top three feet of the ground profile <br />mixed with weathered shale to construct the dike. The Division recommends that A-Horizon soils <br />be segregated for replacement in locations requiring revegetation and that B-Horizon or lower soils <br />be used to construct the dike and backfill the shorelines. <br />• The applicant describes dike construction stating that topsoil and shale will be placed in alternating <br />layers and compacted with a dozer to ensure mixing and compaction. The two types of material <br />must be thoroughly blended to enhance stability. The applicant should describe in detail how this <br />blending of materials will be accomplished. Degree of compaction will be further discussed below. <br />• The application states that the dike and the pond shores will slope at 3:1 for 10 vertical feet below <br />the maximum reservoir water level, then at 2:1 thereafter. The 3:1 slopes should be extended to 10 <br />vertical feet below the ordinary low water mark anticipated for the reservoirs. <br />The Division does not typically require a rigorous discussion of specifications and testing for a dike <br />such as the one proposed. However, the applicant should provide a discussion of maximum lift <br />thickness during construction, the compaction goal as a percentage of maximum dry density, a <br />method compaction specification in terms of the number of passes and the types and sizes of <br />equipment that may be employed, and control of moisture content in the backfill. The application <br />mentions compaction using dozers. A higher degree of compaction could be obtained using rubber <br />tired equipment. <br />• Compaction methods around the cross drain culvert should be described. <br />The applicant should commit to providing a construction report describing installation of the <br />interior dike with each annual report during years that dike construction occurs. The construction <br />report would detail construction observations relative to the general specifications discussed above, <br />and would provide the results of any testing of the backfilled materials. <br />attachment(s) <br />cc: Carl Mount, DMG <br />c:\windows\personal\Fl. Lupton Pil.duc <br />