Laserfiche WebLink
County Road 5/10 will capture runoff from the areas further east of the waste pile. This phase is <br />expected to last two yeazs. <br />• <br />The interim phase 2 includes the expansion of the waste pile into Temporary Basins Tc and Tde at <br />a flat grade up to the level of the interim East Diversion Ditch. The interim diversion will be <br />constructed along the hillside contour above the expanding waste pile and will dischazge into a <br />culvert that runs under County Road 5/10 just east of the primary topsoil stockpile. The diversion <br />ditch on the south edge of the lower pad azea will be reconstructed so that it drains to the <br />ephemeral drainage located west of the site. A culvert will be installed at the portal so that this <br />water will not be impacted by mobile equipment passing through the portal. A collection ditch, Tn- <br />1, will be installed between the expanding waste pile and the county road. Temporary collection <br />ditches will also be installed azound the east edge of the expanding waste pile as topsoil is stripped. <br />These temporary ditches will be at the edge of the stripped area and will flow into collection ditch <br />Tn-1. This phase of the operation is 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. <br />• As the pile is raised, the west diversion channel will be extended further to the east and will <br />become permanent. A permanent diversion channel will also be constructed azound the east side of <br />the pile. Internal collection ditches will remain at the waste pile downslope perimeter and new <br />ditches will be installed along the haul road to the upper waste pile pad area. Phase 3 is expected to <br />extend through the life of the mine. <br />The maximum projected flow through culverts during any phase determined the ultimate size of <br />each culvert. A minimum culvert size of 24 inches was used for all installations to minunize the <br />potential for plugging and to facilitate cleaning. Culverts will be installed at the initial phase of the <br />project or as needed for the next phase to continue. <br />16.2 Packrat Surface Drainage <br />As the Packrat portal area is very small (i.e., about an acre), installation of an unlined collection <br />sump is considered sufficient to control runoff and sediment from the disturbed area. This sump will <br />~~ <br />Whirlwind Mine June 07 D-28 <br />