_INSPECTION - C1981017 (20) - Laserfiche WebLink

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III. COMMENTS - COMPLIANCE Below are comments on the inspection. The comments include discussion of observations made during the inspection. Comments also describe any enforcement actions taken during the inspection and the facts or evidence supporting the enforcement action. This was a complete of the Coal Basin Mine. The operating permit has been revoked at this site, and the reclamation bond has been forfeited. Reclamation of the site is substantially completed. Only maintenance of previously reclaimed mining areas remains to be completed. The Sutey Refuse Disposal Area required maintenance at one of the reclaimed down-drains. Ditch 8, which drains the southerly portion of the facility, had experienced severe erosion as a result of summer rain storms, and a breach in an up-slope diversion channel. A repair design had been prepared by the site Project Manager. This design was developed into a Documented Quote Bid. This competitive bid was awarded to Red Dog Enterprises of Hotchkiss, Colorado. Red Dog began the maintenance work on the date of this inspection. Maintenance of the ditch required excavation of existing channel sediments and previously constructed flow velocity reduction devices. The channel was excavated as needed, and widened toward the east(away from the coal refuse). Approximately 20 coarse rock check dams were established within the excavated channel. These check dams were placed so that their top elevation exceeded that of the reconstructed channel, upon completion of channel reconstruction. Logs and timber slash were placed in the intervening channel segments between the coarse rock check dams. The timber and slash was compacted in place using a tracked excavator with a thumb, to ensure secure contact with the channel bottom and sides. The previously excavated dirt was then placed over the timber and slash to act as the channel base. The entire channel was then seeded with both a fast growing seed mixture and a reclamation seed mixture. Maintenance work is planned at the upper reaches of Road D near the former location of the Mine 3 loadout. This area is subject to heavy runoff from snowmelt and periodic summer rains. Red Dog will perform drainage control work at this location as part of the maintenance contract. Most of the reclaimed mine facilities, including roads and slopes below the mine benches, were evaluated during this inspection. The reclaimed areas were generally found to be functioning as designed. One portion of Road G, approximately one half mile below Mine 5, had been flooded by a tributary to Coal Creek, as a result of an intense rain storm. However, this is not viewed as an event that compromises reclamation integrity, as the reclamation concept for the entire mine site was to allow natural processes to occur un-checked within the Basin. The result of this event was that the affected portion of Road G is now difficult to navigate with All Terrain Vehicles due to deepening of the channel.