2007-06-29_PERMIT FILE - C1981022A (2)

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Se7iar - 2.05.4 sideslopes to m;n;m;~r the potential for erosion from normal variations inflow levek. Riprap will l,e • obtained from one or both etosting permitted borrow sources along the Elk Geek road. Channel reconstruction work will be completed during late sununer or early fall during seasonal low flow periods to the extent reasonably feasible to m;n;m;>e impacts on Elk Geek and downstream on tite North Fork of the Gunnison River. The sub-grade coal stockpile reclaim tunnel is a reinforced concrete structure. This structure will l,e demolished and the mbblized demolition debris will be left in place. The resulting void will allow fgr sub-grade placement of demolition debris from other structures within the Ells Creek Facilities area, Final overall grading of the facilities area and specifically the coal stockpile area and reconstructed E11t Geek channel will generate sufficient excess fill to provide a m;n;~*+um of four feet of cover over tite reclaim tunnel and associated demolition debris disposal area. A material balance for final backfilling and grading attivities was developed based on comparison bf the premising or existing and the postmining topography maps- The reclamation material balance resulted in a cut-fill isopach and material balance table that are included in Exhibit 2.05-E5 Reclamation Details. Generally, drainage and sediment control stmctures including diversion ditches for undisturbed area runoff, collettion ditches for disturbed azea runoff, sedimentation ponds, and localized drainage artd sediment control features and Alternative Sediment Controls will either be retained during final reclamation or reconstructed or replaced by postmining drainage structures during final grading, These drainage and sediment conuol features will remain in place during the initial ponion of ~e reclamation liability period and will be removed, unless previously approved as permanent structures. Removal and reclamation of associated disturbance areas will occur following DMG approval of Phase II Bond Release or the drainage restoration demonstration under Rule 4.05.2 (2). Ditches v~i11 • be reclaimed by reducing the ditch cross-sectional profile by grading ditch sideslopes into the ditch channel and blending the regraded sideslopes with adjacent azeas. Smaller ditches may be reclaitrved and eliminated through natural siltation. When these ditches are no longer needed to conuol drainage and sediment, check dams may be placed at regular intervals in the ditches to reduce flow veloctues trap sediment, and accelerate sediment deposition, allowing the ditches to silt-in over a short tires interval. Retention of ditches along the partially reclaimed or modified Somerset Cemetery road will enhance the long-term stability of the road and these ditches will either be retained or reconswctad. Upgradient collection ditches for the coal mine waste piles aze an integral pan of the design for thESe prtrtratetn atucmtrs• aru' wril' m1~s ~ ,cnminu! .3'etdinrtneui,-tr tst-trtd° .vtil' ~ ,etntsvett; atn~`ss separately approved in the future as permanent impoundments to support the postmining land uSe, and the associated surface disturbance areas will be regraded to blend with the surrounding terra, Sedimentation pond reclamation will involve removal of discharge structures, grading of poi,d etnbankmenrs into the pond basins, and grading of basin and embankment areas to blend with the surrounding terrain and reestablish effective drainage The pre-disturbance land use for this area was undeveloped land and historic mining activities. The affected lands will be reclaimed consistent with the undeveloped land use while maintaining access through the area and to adjacent public lands. As previously noted, the Somerset Cemetery, );]]t Geek, and Sanborn Geek roads will be retained to provide long-term access. Soil Replacement -Topsoil was not recovered or segregated during constnuction and development o f the historic Somerset Mute and the associated surface facilities in the azea now designated as the loner • Elk Creek Facilities area. Soil materials were mixed with and incorporated into other sutficial aid neaz-surface materials and used as fill for construction and leveling of the bench and yard areas. Sittce soil materials are not available for replacement, use of existing surficial materials supplemented by weathered surficial materials generated by final site regrading operations for site reclamation has been approved by the DMG. A tttinimum of 6 inches of weathered surfic;al materiak from selected PR04 2.05-58 Revised May 2001