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TIMETABLES: Timetables for working these areas contain some degree of vagueness with respect to certain • aspects. The ultimate goal is to complete all work on this side of Academy Boulevard as soon as possible. Accomplishing that goal will take time. It also requires the extraction of sufficient sand on the east aide of Academy to produce an area large enough so the processing facilities can move to that side. Before the processing facilities can be moved, most or all bacldilling of Phases 2W and 3W needs to be completed. It is more efficient to complete all this work before moving the plant, even if the movement to the east side of the highway needs to be delayed somewhat. It is not known exactly how long all this will take before the plant can be moved and the area totally reclaimed. It is currently predicted this will take appmzimately 15 years. Hopefully, the expansion of mined areas on the east aide of Academy and the bacldilling of land on the west side of Academy will coordinate such that a smooth transition can occur. Because mining and processing and backfilling are all market dependent, the rate of this change is difficult to predict. However, the mining and reclamation plans of both sides of Academy Boulevard have been coordinated in such a way that even if the actual time certain events occur shifts, the temporal relationship between those events should remain essentially as designed. NATURE OF DEPOSIT AND UNDERLYING MATERIALS: The gravels in Phase 2W are about 10 to 20 feet thick and tend to be quite variable. This variability exists because these gravels were laid down by meanders in Fountain Creek a very long time ago. Underlying the gravel is shale. This shale exists under all the alluvial and aeolian • deposits in this part of El Paso County. Where sand is present it is 90 to 100 feet thick and often rests on top of about 10 to 20 feet of coarse gravel. The gravel rests on top of the shale discussed above. In some places the gravel is missing and is replaced by sand which rests on top of shale. The pattern of this variation has never been determined with accuracy, but is indicated by ground water patterns. Generally, the gravel acts as an aquifer. Where water occurs gravel is usually found. But where water is not found the gravel is usually missing or is a minor component of that layer. Past drilling reflects this variation. Some holes never encounter water and those that do exhibit highly variable flow rates. At this point, it appears the presence of the gravel layer is more common than its absence. East of Academy Boulevard METHOD OF MINING: Mining on the asst side of Academy will follow the sequences depicted in the sequence maps included at the end of this exhibit. Two methods are available for mining this sand deposit. First, is to mine the sand in benches or Lifts. The second method is to mine the sand to full depth along a working face as has been previously done. • East of Academy Mining Plan Page Q7 ,~