2013-01-29_PERMIT FILE - C1981022A (3)

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Section - 2.05.3 Maintenance for clean water diversions will include periodic inspection for excessive erosion or damage and repair and clean-out as necessary to maintain an adequate channel profile and assure that the ditches continue to function as designed. On completion of active operations and reclamation of the associated disturbance areas, the clean water diversions will be maintained through the reclamation liability period and then removed in conjunction with sedimentation pond removal. Ditch removal may involve some discretionary judgement. In some cases, it may be adequate to block the ditches and allow them to silt-in. In others, it may be necessary to backfill, regrade, and revegetate the ditch areas. Mine Runoff Collection Ditches and Containment Berms -Mine runoff collection ditches and/or berms have been constructed for most mine disturbance areas to intercept disturbed area runoff and route it to either sedimentation ponds or through alternative sediment control structures. Runoff collection ditches and berms are designed to minimize erosion and additional sediment contributions and to safely pass design flows while maintaining adequate freeboard. Where design flow velocities would result in excessive erosive forces, adequate channel protection is provided to prevent erosion and down-cutting. Runoff collection ditches and berms are identified and associated design calculations for both the ditches/berets and associated culverts are provided in Exhibit 2.05-E3, Drainage and Sediment Control Plan. Ditch/beret locations and configuration are shown on the Drainage and Sediment Control Map, (Nlap 2.05-M4). Maintenance and reclamation practices for runoff collection ditches and berms will be essentially the same as previously discussed for clean water diversions. Small Area Exemptions and Alternative Sediment Controls - As previously discussed, OMLLC utilizes Alternative Sediment Controls where feasible in order to control drainage and sediment as close to its source as possible and to avoid any unnecessary additional surface disturbance. Alternative Sediment Controls are also used for small-scale temporary disturbances as the most effective control approach. Alternative Sediment Controls typically consists of one or a combination of the following control measures: • Silt fences, straw bales and wattles • Vegetative filters • Erosion control matting • Surface manipulations (pitting, contour ditches, surface roughening) • Mulch applications Where associated disturbance areas are small or isolated, OMLLC has received approval for the following Small Area Exemptions in accordance with applicable provisions of Rule 4.05.2(3). The specific Exhibit 2.05-E3 section has been noted where the documentation required under Rule 4.05.2(3) for each Small Area Exemption is provided. • Upper Hubbard Creek soil stockpile (Exhibit 2.05-E3, Sec. 4, page B-142 and B-149) • Lower Hubbard Creek facilities area (2 SAE's) (Exhibit 2.05-E3, Sec. 4, page B-141) • Bear Creek facilities area (Exhibit 2.05-E3, Sec. 4, page B-141) • Sanborn Creek Mine portal area (Exhibit 2.05-E3, Sec. 3) • Sanborn Creek Mine overland conveyor (two SAE's) (Exhibit 2.05-E3, Sec. 3) • Elk Creek Mine Area (5 SAE's: soil stockpile, Slope 1, Slope 2, North area and Storage area) (Exhibit 2.05-E3, Sec. 9) • CBM - Degasification Well Pad Areas (Exhibit 2.05-E3, Sec. 9) • Bear Creek Shaft and Fansite (2009) (Exhibit 2.05-E3) Small Area Exemptions and areas where Alternative Sediment Controls will be used are also identified on the Drainage and Sediment Control Map, (Map 2.05-M4) and Bear Creek Fansite (Map 2.05-E1- BCA2). Small Area Exemptions and areas where Alternative Sediment Controls are utilized will be inspected periodically for indications of damage, TR-60 2.05-37 Revised Nov. 2008