2014-03-05_REVISION - M1977211 - Laserfiche WebLink

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.r r "CEIVIED 05 N14 DIV __ -)N OF 2ULAMv F' '• MINiNGMI) SAFETY February 28, 2014 Mr. Tim Cazier Colorado Division of Reclamation, Mining and Safety 1313 Sherman, Suite 215 Denver, CO 80203 Subject: Technical Revision, M -77 -211 Continental Materials Corporation, Transit Mix Aggregates, Castle Concrete Pikeview Quarry Dear Mr. Cazier, Transit Mix Aggregates requests a Technical Revision to the Applicant's Pikeview Quarry operation. This Technical Revision to Amendment 3, which satisfied the board cease and desist order, proposes to change the mining sequencing, expand mining in the plant area, and to add non - traditional quarry mining methods. The modifications proposed in this Technical Revision will not impact the permit boundaries. The mining sequencing in Amendment 3 utilized a phased approach with mining and reclamation progressing from north to south in a top -down manner. Recent inclinometer data suggest the ongoing pitwall movements are progressing northward, and the Applicant proposes to begin mining and reclamation operations at the southern extent of the mine for safety reasons. The Applicant anticipates mining from south to north after finishing the Horseshoe area, but the sequencing will be evaluated after each phase. Subsequently, the safest phase will be mined. All mining and reclamation will be performed in a top -down manner. The Applicant proposes to commence mining and reclamation in the only area that can currently be accessed safety — the south horseshoe. Mining this area will produce the initial fill volumes required to buttress the pitwall slope and allow safe access to the subsequent mining phase. Mining will continue in this manner with the Applicant mining at the top of the slope, filling at the bottom of the slope in advance of the mining operations, and removing and processing limestone where possible. Amendment 3 included mining between the plant and Area H, and the Applicant proposes to continue mining this area, with all mining occurring within previously disturbed areas. The mining will progress east to the center of the plant, which may have to be partially removed. Site conditions, mainly the steep gradients and landslide, will likely require using the non- traditional mining methods of yarder and slusher operations. The Applicant will continue to use Pikeview Quarry Technical Revision February 28, 2014