2011-04-19_REPORT - M1977004 - Laserfiche WebLink

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elevation. The success of the experiment will continue to be monitored and enhanced in 2011. 3.2 Tie Camp Creek Disposal Cell In 2001 and 2002, dismantled building material from the former RTP, concrete and contaminated soils removed from the immediate drainage, were removed and placed in a Disposal Cell near the toe of Tie Camp Creek Low-Grade Stockpile. This cell was created in mid-1990 as a clay-lined repository for materials dredged from the Sediment Control Pond. The cell, as shown on Figures 2 and 3, was left open with sufficient capacity for the RTP demolition material. The demolition material and contaminated soil placed in the cell were crushed and compacted. In 2003, the cell was shaped and prepared for the placement of a clay cap. Placement and compaction of a clay cap was completed in 2004. A final layer of topsoil (minimum 24 inches) was added and compacted on top of the clay cap during 2005. In 2007 and 2008, finish grading was conducted on the topsoil cover to eliminate any low spots where water could pond, and to enhance drainage on and around the disposal cell. Harrowing, scarifying and reseeding of the surface of the disposal cell area were completed in 2007, 2008, 2009 and 2010 to improve the cover stability and to minimize erosion. The vegetative cover on the disposal cell cover is showing success. All reclamation work was conducted in accordance with conditions in the RML and the Pitch Reclamation Project Procedures Manual. 3.3 Erosion Control in the North and South Pits and Waste Rock dumps Snow melt, summer precipitation and springs in the east wall of the North Pit have been recurring issues since the pit was developed. This problem has been exacerbated over the past few years by heavier snow pack in the mine area. On the east wall of the North Pit, minor erosion in the form of rill development, has occurred between the 10,800 and 10,600 elevations due to snow melt runoff. This area at the crest of the east wall of the North Pit is a topographically low area that concentrates surface drainage from a relatively large area above the crest of the east wall. The area will be regraded as weather and ground conditions permit each year, to capture and channel surface water to discharge at an outcrop of competent rock that is adjacent to the current area of discharge. Flow will be channeled to the "Spring Creek" channel that flows at the 10,600 bench. Straw bales were staked in place at the area above the pit crest late in the fall of 2010, to slow surface water velocities and reduce the impact of surface erosion until the more permanent re-grading work Pitch Reclamation Project Colorado Mined Land Reclamation Board 2010 Annual Reclamation Report 6