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0/28/2005 11:47 970834020404 PAGE 04 JOE INTERMILL PAGE3 EXEIIBTT E-RECLAMATION PLAN: Paragraph (a) of the Reclamation plan shows that 4 water storage ponds are proposed, ranging in size from 23 acres to 94 acres. They total approximately 277 acres of surface area. Reclamation plan, map 6, shows two ponds, one at 86,4 acres and one at 175 acres. There is also an area labeled 19.3 acre wetland/pond area . Which is correct, the oarrarive or the map? Our concern is with the amoum of wave action erosion that can be created by wind blowing overl/2f mile of open water. We are also concerned by the premise of mining the claystone and utilizing it as the material for the clay lining in the ponds..Ms. Ortiz and Mr. Reiner have arranged for us to view a similar operation next week at a nearby location. It is understood that mining and reclamation schedules are difEcult to establish considering that the operation is driven by market demand, weather, and mrmerous other factors that the operator is unable to control. However, suer reviewing pertinent supplemental data submitted with the easement information, the Reclamation Plan, the lvfining Plan, and the various maps, it appears that the ] :2 slopes between the buffer area and the excavated area could stand untreated for somewhere between 2 and 9-1 /2 years before the clay lining is completed. The only reason this is of concern to CDOT is that steep slopes , leR for an extended period o£time tend to erode and cave back into the adjacerrt material. This situation could potentially reduce the width of the natural buffer area between the pond and the CDOT ROW. Also, are there drainage trenches along the toe of the slopes paralleling HWY 85? If so, since these western pods are scheduled to be mined earlier, will the slopes be left unlined until completion of excavation in the area so as not to disrupt the drainage operation? Ts there a provision for some type of keying operation to help bond the clay liner to the claystone bedrock, and prevent the intrusion of water between the liner aad the bedrock? Tt is assumed that the liner material will be placed in horizontal lifts with some type of keying or benching into the adjacent alluvial sand and gravel. 1. Is there a maximum loose or compacted lift thickness? 2. What type of wmpacxion equipmem will be used? 3. Will moistureldensitytests be required on the compacted liner, and if so at what frequency? The slope stability calculations were submitted to the CDOT Geotechnical Unit for their review and comments. We anticipate their report early this week.