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TRAPPER MINIM 11CM <br />February 11, 2010 <br />Mr. Jason Musick RECEIVED <br />Environmental Protection Specialist ZQ10 <br />Colorado Division of Reclamation, Mining and Safety FEB 1 <br />13 13 Sherman Street, Room 215 Divis'ufl ul reclamation, <br />Denver, CO 80203 Mining and Safety <br />Re: Trapper Mining Inc., Permit No. C-81-010, Technical Revision 106 <br />Dear Mr. Musick: <br />Trapper Mining Inc. is submitting this Technical Revision to incorporate mine sequence and other <br />changes that have occurred since PR-6 was submitted. A description of the revision follows as <br />well as references to the maps, text, reports and figures that have been changed, removed or <br />added. <br />K-Pit Mining Sequence: With assistance from Agapito Associates Inc. (AAI), Trapper <br />developed and submitted a revised ground control plan to MSHA that included a mining sequence <br />for the slide area. That sequence was different than the one submitted with PR-6. Rather than <br />commencing stripping of K pit in.the middle or "B" block of the pit, the actual sequence began <br />stripping in the "C" block at the top or head of the slide. This sequence modification improves <br />stability and generally keeps the slide material below the workings. <br />K Pit Buttress: During the course of the ground control plan evaluation, the need for a buttress <br />was reexamined. Upon further analysis the determination was made that a buttress is not needed <br />for stability. Further, the placing of a large amount of material on the old East A-pit spoils north <br />of the slide area may have resulted in instability in these backfilled areas. AAI recommends that a <br />smaller amount of spoil (incorporating one - 50' lift) be placed on what was formerly a more <br />substantial buttress fill. Much of the material that was originally destined for the buttress will be <br />hauled to the final cut in F pit. Text pages 3-15, 3-15a, 3-15b, 3-39, 3-39a, 3-40-3-40b, 3-43, 3- <br />44, 4-235, 4-238j and maps M4, M 1 OA, sheet 3 and M 1 OB, sheet 3 have been revised to reflect <br />the change in sequence and eliminate the buttress. Map M12, sheets 2 and 3, and M14A have <br />been revised to reflect associated changes in the projected post mining topography. AAI's <br />Revised K-Pit Buttress Fill Stability Analysis and Recommendations is also attached. <br />Roads: The road system feeding the K pit area was also modified to accommodate the revised <br />sequence. Map M9, sheet 3 shows the new layout. With the exception of the eastern roads coming <br />across L-pit, all of these roads will be mined through before or during 2012, the worst case year <br />for reclamation liability. Liability calculations for the remaining 7,440 feet of road are included in <br />this revision. <br />Monitoring: A new slide stability monitoring system was designed in conjunction with the <br />development of the ground control plan. This system consists of four sites. Three of the sites <br />consist of an inclinometer, piezometer and CPS station. The fourth site consists of an <br />inclinometer and piezometer without a GPS station. Each site has a single borehole where <br />inclinometer and piezometer instrumentation is installed. Each instrumentation site is equipped <br />P.O. Box 187 Craig, Colorado 81626 (970) 824-4401