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Upon final reclamation, all temporary diversion ditches, berms and culverts will be <br /> removed, and ephemeral drainages will be reconstructed in their approximate <br /> original locations. Fill embankments in locations where the haul road crosses <br /> McClane Creek will be removed and the approximate original channel <br /> configurations will be restored. <br /> Diversion design is addressed in Sections 2.4.1 and 2.4.4 of the application. Channel <br /> reconstruction is discussed in Section 3.5 of the application. Applicable maps and <br /> tables are referenced in the cited text sections. <br /> The following specific approval is required by Rule 4. <br /> 1. Rock riprap lining is proposed for use to control erosion in certain reclaimed <br /> ephemeral stream channels. This measure is proposed to be approved by the <br /> Division, since the riprap lining is necessary to control erosion, and the lined <br /> channels will be stable and will require infrequent maintenance (4.05.4(2)(a)). <br /> C. Sedimentation Ponds <br /> There is one sedimentation pond at the mine, located between the portal bench area <br /> and the office facilities area, on the south side of the haul road. The pond treats <br /> runoff from the portal bench disturbed area,the upper segment of the haul road <br /> surface and cut slopes, and a small supply storage area. The pond is oversized <br /> (storage volume adequate to contain the sediment and runoff from multiple 10 year, <br /> 24 hour precipitation events below the level of the gated 8" primary discharge pipe). <br /> In addition to the primary discharge pipe,the pond has an open channel emergency <br /> spillway designed for the 25-year, 24-hour precipitation event. The sedimentation <br /> pond is discussed in Section 2.4.4 of the text, and designs are depicted on Figure 2.2- <br /> 3 of the PAP. <br /> The sediment pond was filled in with sediment by a 100 year magnitude storm event <br /> in August 2001 that had buried and overwhelmed one of the primary upland <br /> diversion culverts. In association with excavation of sediment,the inside slopes of <br /> the sediment pond were reduced to approximately 21-1:1V. The re-constructed pond <br /> was properly certified by a professional engineer(see "Impoundment Yearly <br /> Inspection" of March 29, 2002). The pond embankment failed in 2004, apparently <br /> as result of leakage from the buried primary discharge pipe. The embankment was <br /> reconstructed and the primary discharge pipe was replaced. Embankment <br /> reconstruction was properly certified (see"Sediment Pond Certification" of <br /> December 14, 2004). <br /> D. Surface and Ground Water Monitoring <br /> GROUND WATER <br /> xvi <br />