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Cmc CONTINENTAL MATERIALS CORPORATION <br /> the existing roads at the crest of the quarry so that water is collected and conveyed to the north <br /> or south. Diverting this water away from the quarry walls will limit flows and seeps into the fracture <br /> zone. Second, is preventing heavy sediment and stormwater flows from leaving the site. This <br /> is accomplished by maintaining, as much as possible, "informal" detention basins within the <br /> mine. These are "informal" in that they are composed of mine pits and other depressions <br /> that simply capture stormwater and sediment and prevent it from entering the lower portions of <br /> the permit where the more "formal" controls identified in TR-7 (1994) are present. The <br /> "depression" in the pit is expected to last throughout the mining and reclamation grading phase <br /> and will be the last area graded. <br /> The "formal" stormwater controls include the use of culverts to direct the water and sediment <br /> to a series of detention basins that capture the sediment and allow much cleaner water to pass <br /> through. Open drainage paths will be armored with riprap. <br /> A final detention basin near the east edge of the permit that was constructed before <br /> May 27, 1994, provides a final treatment area. This basin was included in the stormwater <br /> management facilities technical revision submitted in January 1994. This allows for capture of <br /> any sediment that bypasses the upper sediment basins and riprap channels. <br /> Near conclusion of the reclamation construction,the quarry depression will no longer be available <br /> for sediment control. Runoff will be routed to the northeast through the sediment pond, when <br /> practical, and best management practices will limit offsite sedimentation in other locations. <br /> Discharge and sediment volumes should not be greater than current volumes and will probably <br /> be much less. This is because nearly all the land at the end of the reclamation will be <br /> revegetated. At present, most of the sediment that needs to be controlled comes not from <br /> revegetated areas, but from nonvegetated roads, mining, and processing areas. This sediment <br /> control will be managed using the existing facilities near and after the end of reclamation. <br /> Reclamation Drainage Plan <br /> The reclamation drainage plan includes a network of terraces and ditches designed to convey <br /> runoff from the graded and reclaimed slopes to the existing sediment control structures previously <br /> described. Terraces will collect sheet flow occurring on the reclaimed slope and divert it to <br /> armored ditches on the edge of the reclamation slope. <br /> Design of the channels and calculation of run off quantities were carried out using SEDCAD <br /> Version 4, a commercially available software package that calculates the runoff response to a <br /> given precipitation event for specific surface topography, soil, and vegetative cover conditions <br /> using subroutines from TR-55 (USDA-SCS, 1986). Application of the SEDCAD 4 program <br /> involves subdividing the drainage area into sub-watersheds with relatively uniform surface <br /> Pikeview Quarry Amendment 4 <br /> G-3 <br />