PERMFILE50066 - Laserfiche WebLink

Home Browse Search

03'128!2095 11:47 970834029404 JOE INTERMILL PAGE 04 PAGE3 EXHiBTT E-RECLAMA77ON 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 wethuuUpond area . Which is correct, the oaRative or the snap? Our concern is with the amount of wave action erosion that can be created by wind blowing over1/2f mile of open water. -- --- ----- --- - - - - ~Ve are also conoemad~by ttie piemtse of muvng the cCaystone and utilizuag it as the material for the clay lining in the ponds, Ms. ORiz and Mr. Rainer have arranged for us to ' view a similar operation next week at a nearby location. It is understood that mining and reclamation schedules are difficult to establish considering that the operation is driven by market demand, weather, and m~merous other factors that the operator is unable to control. However, after reviewing pertinent supplemental data submitted with the easement i~'ormation, the Reclamation Plan, the lvfuiin~Plan, and the various maps, it appears that the 1:2 slopes between the buffer area and the excavated area could stand untreated for somewhere between 2 and 9-1(2 years before the clay lisring is wmpleted. The otdy reason this is of concern to CDOT is that steep slopes ,left for an extended period of time tend to erode and cave back into the adjacem 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 tce 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 wmpacted lift thickness? 2. What type of compaction equipment will be used? 3. Will moisture/densitytests 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.