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Pond 8 collects run-off from the South Portal and the RSRDA. The pond was damp <br />during the inspection. Volume III, Appendix 13-2, page RSS-1 shows that its design <br />water and sediment capacities are 0.68 A-F and 0.22 A-F respectively. On February 13, <br />2008 the undersigned certified the water and sediment capacities of pond 8 at 0.76 A-F <br />and 0.22 A-F respectively. It is a dugout pond which must be dewatered with a pump. <br />There is and estimated 10% sediment buildup in the pond. Based on this sediment <br />buildup the pond has the following estimated capacity: <br /> Water Sediment Total <br />Pond 8 - A-F 0.76 (0.22*0.9) =0.2 0.96 <br />Pond 9 collects run-off from the South Portal and RSRDA. The pond was dry during <br />the inspection. Volume III, Appendix 13-2, page RSS-15 & 15i shows that its design <br />water and sediment capacities are 0.33 A-F and 0.33 A-F respectively. The sediment <br />was removed from the pond during 2003 so the pond had a total depth of 9-feet. <br />Sediment (2.6) has accumulated in the pond since it was cleaned. The percent of <br />sediment buildup is 60% (2.6' deep divided by 4.3' maximum depth). Based on this <br />sediment buildup and a 2003 survey of the pond after sediment was removed, the pond <br />has the following estimated capacity: <br /> Water Sediment Total <br />Pond 9 - A-F 0.66 0.15 0.81 <br />Pond 10 collects run-off from CRDA-2. The pond was dry during the inspection. <br />Volume III, Appendix 13-2, page CRDA2-1 shows its design water and sediment <br />capacities are 1.37 A-F and 1.23 A-F respectively. There are approximately 3.2-feet of <br />sediment buildup in the pond. This figure is derived from the average length of the two <br />sediment poles located in the pond minus the design depth. The percent of sediment <br />buildup is 60% (3.2' deep divided by 5.3' maximum depth). Based on this sediment <br />buildup and aerial topo maps, the pond has the following estimated capacity: <br /> Water Sediment Total <br />Pond 10 A-F 1.48 0.53 2.01 <br />Pond 11 collects run-off from Cameo Borrow Area No 2. The pond was dry during the <br />inspection. The Operator obtained approval from DRMS, (TR-47), to amend the design <br />of the pond so it relies primarily on storage to control run-off from the design event <br />(DRMS Rule 4.05.9(2)(e)). Therefore, the open channel a primary spillway is not <br />required. The design event the pond must contain is the 25-year event which <br />generates 0.47 A-F of sediment and 0.66 A-F of run-off for a total required pond <br />capacity of 1.13 A-F. During 2006 the pond received a substantial amount of sediment <br />from an overflow of Coal Gulch. The estimated capacity of the pond was reduced from <br />5.7 A-F to 3.5 A-F. The pond is still significantly oversized for both sediment and water <br />capacity. <br />-2-