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Integration of Layback and Enhanced Amendment Plans <br />Pikeview Quarry <br />Feb~aryE2,' VED <br />JUN 0 9 2003 <br />Background Division ~f Minerals and Geology <br />In the mid-1990's an amendment was approved for the Pikeview Quarry that included the <br />Enhanced Reclamation Plans. This amendment modified the mining plan to remove previously <br />permitted lands and substitute an over-excavation hole at the base of the quarry backwall. <br />Mining progressed since that time primarily under the direction of the late Greg Francis. <br />However, mining did not progress to the point where the over-excavation was actually begun. At <br />the time of the development of this integrated plan there was still a considerable amount of <br />limestone to be removed at the base of the quarry backwall before the over-excavation is actually <br />started. The over-excavation was referred to as Area H in that amendment and that name is <br />carried over into this plan. <br />Late in the 1990's consideration was given to laying back the backwall of the quarry to <br />produce a more reclaimable surface and configuration and to remove much of the remaining <br />limestone forming the current backwall of the quarry. The problem with that limestone is that it <br />is highly unstable due to the steep (34 degree) dip of the rock away from the mountain. Although <br />bench reclamation methods have been changed since the Enhanced Reclamation amendment and <br />that has considerably improved stability where that was used, all the old mining benches remain <br />in a highly unstable condition. Reclamation of those old benches without drastic modification is <br />probably not possible. Therefore, the Layback amendment was developed and approved. <br />In 2002 the Layback was started on the most southerly of the two peaks involved in that <br />plan. It began here because of ready access to that land. Granite produced from the excavation of <br />this initial Layback work was pushed over the quarry face and formed a long talus slope that <br />ended on the bench below the backwall and more or less in the middle of the quarry. By late <br />2002, work on the quarry began to encounter problems with this Layback work. In brief, the <br />problem was twofold. First, there was a lack of room to dispose of the material coming from the <br />Layback work without contaminating the limestone. Second, continued excavation of limestone <br />to reach the Area H elevation (about 7250') was becoming increasingly difficult without creating <br />difficulties in the haulage of the limestone to the processing plant. <br />Near the end of 2002, Mark Heffner and BJ Fuller were asked to examine this situation <br />and see if a solution could be found to alleviate these problems. <br />