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20 <br />Ditch 29 collects runoff from 67.2 acres of undisturbed runoff and directs this runoff <br />to the lay down area without impacting any disturbed area. Culvert C -27 has been <br />installed at the east end of the lay down area to handle peak flows from Drainage <br />Basins CC and DD as shown on Map 13A- Drainage Basins. <br />Ditches 39a and 39aa are proposed to route storm water around the cut slope of the <br />substation and rock dust system to maintain the integrity of the slope. At the time of <br />construction, the slope material characteristics will be evaluated to determine if a <br />drop structure is necessary to carry the cut slope runoff. The details of the cut slope <br />are included as Figure 2d. <br />Sedimentation control for the RDA haul road is shown on Map -13. Runoff from the <br />haul road will be managed with ditches and culverts and the design for each structure <br />is included in Exhibit 19(24). Runoff from the haul road is not considered to be in <br />the disturbed area as deemed by Rule 4.05.2(4) and is therefore not routed to a <br />Sediment Pond. <br />Sedimentation control at the Bates Portal is shown on Map 13 -A Sediment and <br />Surface Water Control Silo Area. Six new ditches and four new culverts and the <br />design size and routing of each structure are provided in Exhibit 19 (16). Runoff <br />from the 10 -year, 24 -hour event at the Portal will be routed to Pond 007. <br />The C & W train shop, 10 -stall garage and other associated structures are located on <br />the west side of the east mine sedimentation control system. The land slopes <br />approximate 2% from the C & W train shop to the east towards pond 7. Flow from <br />this general area will be collected in either ditch D -5 or D -6 and conveyed to <br />sediment pond 7 and can be found on Map -13C, West Side of the East Mine - <br />Sedimentation Control Plan. <br />A small area exemption has been established for subsoil storage pile #1 due to its <br />proposed location outside of areas where disturbed runoff will be routed to a <br />sediment pond. Berms and silt fences provide alternative sedimentation control for <br />this area. The design of the silt fences are included Exhibit 19(16). This SAE area is <br />shown on Maps 11 and 12. <br />The proposed DWDA #2 storm water management above, around and on the waste <br />pile was evaluated for a 100 year, 24 -hour storm event. The results indicate that the <br />management system already in place for the site will safely pass the storm with the <br />recommendation that the berms and ditches are field verified to be constructed as <br />designed. The storm water routing near the DWDA #2 is shown on Figure 2e. The <br />runoff above (North) is diverted through Ditch D -11 through culvert C -30, ditch D -1, <br />culvert C -26, and ditch D -32 to the river. This is shown in Figure 2e. Exhibit 39 <br />Sediment Design Specification- Development Waste Disposal Area demonstrates that <br />the existing ditches are appropriately sized to carry the storm water above the <br />DWDA #2. <br />The DWDA #2 runoff is routed through a small catchment into culvert C -13 and to <br />Section 2.05 TR -68 12/10/2014 <br />