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applied. These activities can include, but are not limited to, rock channels, contour furrows or
<br /> laterals with rock or matting bottoms, V ditches made with the dozer or motor grader, and
<br /> subsequent revegetation. Head cutting in channels will be controlled by a number of methods. If
<br /> the area is at a point that concentrates runoff, the area will be improved to accept this runoff. This
<br /> would include reshaping the channel and channel bottom, covering with erosion matting, seeding,
<br /> or rocking. Inlet channel erosion will be controlled down to the average water level of the ponds.
<br /> Remedial action on pond slopes will extend as far down the slopes as equipment access allows,
<br /> which at a minimum will be below the level of the principal spillway of each pond. In other areas,
<br /> depending on the extent of erosion and time of year, the area will be regraded, disked, and seeded
<br /> as needed. Straw bales, erosion matting, or rock fill may also be used to stabilize the area.
<br /> Should an area need repaired that requires a more long term control method, New Horizon may
<br /> employ additional measures including erosion control blankets,straw wattles,silt fences, silt fence
<br /> like products, small riprap structures, mulches, small check dams, small rock structures including
<br /> rock basket(s) to reduce runoff volume. If repairs are required, all areas that have been mitigated
<br /> will be seeded with an appropriate approved seed mixture. Prior to any erosional mitigation work
<br /> occurring,the surface landowner(unless it is New Horizon private property)will be contacted for
<br /> their approval of the proposed remediation measures. If any of the above mentioned sediment
<br /> control measures are employed, they will be used inside the primary sediment control systems or
<br /> in conjunction with small area exemptions (SAE).All surface mining operations will be conducted
<br /> to achieve the effluent limitations of 4.05.2(7) for all mixed drainage when it leaves the permit
<br /> area. Sedimentation ponds, diversion ditches,or impoundments will be constructed before creating
<br /> new disturbances, unless approved drainage diversions or other surface water control structures
<br /> are installed.
<br /> C. Collection Ditches, Culverts and Diversion Design Parameters
<br /> All ditches were designed and constructed in accordance with the applicable regulations in 4.05.3.
<br /> Diversions will be designed, constructed, and maintained in a manner which prevents additional
<br /> contributions of suspended solids to stream flow and to runoff outside the permit area,to the extent
<br /> possible,using the best technology currently available. Appropriate sediment control measures for
<br /> these diversions may include,but not be limited to, maintenance of appropriate gradients, channel
<br /> lining,revegetation, roughness structures, and detention basins. No diversion will be located so as
<br /> to increase the potential for landslides. When no longer needed, each temporary diversion will be
<br /> removed and the affected land regraded, topsoiled, and revegetated in accordance with 4.06, 4.14,
<br /> and 4.15. If the temporary diversion was for an ephemeral stream,the channel will be reestablished
<br /> to functionally blend with the undisturbed drainage above and below the area to be reclaimed.
<br /> Diversion design will incorporate the following:
<br /> a. Most ditches will not need to be lined; however, any stretch of collection ditch which has
<br /> a velocity above 5.5 feet per second will be lined. Channel linings, including channel
<br /> riprap, will be designed using standard engineering practices to pass safely the design
<br /> Section 2.05.3(3) Page 4 July 2020 (TR-99)
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