2015-11-16_REVISION - M1985043 - Laserfiche WebLink

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/(-Y Azurite, Inc. 10001 CR 12 P.O. Box 338 Cotopaxi, Colorado 81223 719-942-4178 Tim, Cazier, PE, Environmental Protection Specialist Colorado Division of Reclamation, Mining, and Safety 1313 Sherman Street Room 215 Denver, CO 80203 November 6, 2015 tkecoveD 01 i62015 �► OMSioN OF ikEMP ANI1ON WANG PN© SPF RE: RESPONSE TO DRMS TECHNICAL REVIEW OF HIGHWALL STUDY 1) Section A -A' shown on the Highwall Survey map is intended to show a typical cross section of current mine operations as well as projecting the direction of the final highwall build out at completion of mining. For clarity purposes, the highwall survey map has been revised to show a longer typical cross section line than shown on the original submittal with additional features also shown. Depending on factors such as the demand for lower hardness landscape and oversize rock, the final highwall configuration will be located normal(perpendicular) to the general line of direction of A -A', as well as east of the current top mining benches. The survey map cross section attempts to depict as accurately as possible the projected final location of the highwall build out at a point east of the current top highwall benches but still within the permit boundary east of the current working area. The differences in the number of benches at final build out will depend on the extent of mining to east. Due to topography, the upper mine benches may be reduced if mining continues to the eastern border of the permit boundary, well east of current disturbance. Thus, the final build out of highwall benches may be reduced to as low as five 40'benches or as many as eight 40'benches. For conservative estimate of overall slope stability, an eight bench build out (the maximum vertical height projected) was used for all risk calculation. (See each analysis cross section). Thus, to clarify the location of the projected final highwall build out, it will be located normal to the directional component defined by A -A' but will be east of point A on the map and will likely top out near the eastern permit boundary set -back as shown on the TR Revision No. 2 Reclamation Plan Map. Due to market and site conditions that will clarify over time, it is not possible to accurately project the exact location of the final highwall structure at the present time. More importantly, the type of rock in which the final highwall bench structure will be built, the characteristics of the rock, and the final overall slope of the structure have been addressed in this report.