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• During the initial phase, the existing lower pad will be expanded northward to its final design stage. <br />An initial collection ditch Gla will be constructed along the east toe of the waste pile that will carry <br />runoff from the pile to the sediment pond. This temporary collection ditch will be utilized until such <br />time the interim phase 2 starts. An existing East Diversion Ditch (Tc-1) along the south perimeter of <br />the waste pile will divert surface water runoff around the pile to a small natural channel located east of <br />the waste pile. A second Diversion Ditch (Tde-1) located along County Road 5/10 will capture runoff <br />from the areas further east of the waste pile. This phase is expected to last two years. <br />The interim phase 2 includes the expansion of the waste pile into Temporary Basins Tc and Tde at a <br />flat grade up to the level of the interim East Diversion Ditch. The interim diversion will be constructed <br />along the hillside contour above the expanding waste pile and will discharge into a culvert that runs <br />under County Road 5/10 just east of the primary topsoil stockpile. The diversion ditch on the south <br />edge of the lower pad area will be reconstructed so that it drains to the ephemeral drainage located <br />west of the site. A culvert will be installed at the portal so that this water will not be impacted by <br />mobile equipment passing through the portal. A collection ditch, Tn-1, will be installed between the <br />• expanding waste pile and the county road. Temporary collection ditches will also be installed around <br />the east edge of the expanding waste pile as topsoil is stripped. These temporary ditches will be at the <br />edge of the stripped area and will flow into collection ditch Tn-1. This phase of the operation is <br />expected to last 3 to 4 years. <br />The final phase 3 of the project will consist of gradually raising the east portion of the waste pile. As <br />the pile is raised, the west diversion channel will be extended further to the east and will become <br />permanent. A permanent diversion channel will also be constructed around the east side of the pile. <br />Internal collection ditches will remain at the waste pile downslope perimeter and new ditches will be <br />installed along the haul road to the upper waste pile pad area. Phase 3 is expected to extend through the <br />life of the mine. <br />The maximum projected flow through culverts during any phase determined the ultimate size of each <br />culvert. A minimum culvert size of 24 inches was used for all installations to minimize the potential <br />for plugging and to facilitate cleaning. Culverts will be installed at the initial phase of the project or as <br />• needed for the next phase to continue. <br />Whirlwind Mine 07 (rev. April 08) D-31 <br />