2012-04-05_HYDROLOGY - C1981041 (6)

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SNOWCAP COAL COMPANY NORTH AND SOUTH PORTALS IMPOUNDMENT YEARLY INSPECTION In accordance with Rule 4.05.9(14), all impoundments shall be inspected at least yearly to determine if the impoundment has been maintained as designed, and in accordance with the approved plan and the applicable regulations. This yearly inspection is for the impoundments located at the North and South Portals and Refuse Disposal Areas. On March 15, 2012, I performed the required yearly inspections. I, J. E. Stover, have a wide variety of experience in the design and construction of earth fill embankments. Nothing was observed during the inspection that would indicate the ponds have a potential for failure. There was no appearance of erosion, instability, structural weakness or other hazardous conditions. There are no required monitoring procedures or instrumentation other than quarterly and yearly inspections. There are no aspects which might affect stability and there is no required maintenance. None of the pond /impoundments were discharging during the inspection. Pond 6 collects run-off from CRDA -1. The pond was dry during the inspection. There are approximately 2.3 -feet of sediment buildup in the pond. This figure is derived from the average length of the three sediment poles located in the pond minus the design depth. The percent of sediment buildup is 43% (2.3' deep divided by 5.4' maximum depth). Based on this sediment buildup and aerial topo maps, the pond has the following estimated capacity. The estimated water capacity of Pond 6 is less than the original design requirement of 1.49 acre feet. However, calculations presented in Volume III, Appendix 13 -2, page CDRA -1 -1 ii, based on the partially reclaimed and vegetated refuse pile indicate the required water capacity of Pond 6 is only 0.68 acre -feet. Pond 7 & 8 were reclaimed in 2011 Pond 9 collects run -off from the South Portal and RSRDA. The pond was dry during the inspection. Volume III, Appendix 13 -2, page RSS -15 & 15i shows that its design water and sediment capacities are 0.33 A -F and 0.33 A -F respectively. The sediment was removed from the pond during 2003 so the pond had a total depth of 9 -feet. Sediment (2.6) has accumulated in the pond since it was cleaned. The percent of sediment buildup is 60% (2.6' deep divided by 4.3' maximum depth). Based on this sediment buildup and a 2003 survey of the pond after sediment was removed, the pond has the following estimated capacity. Pond 10 collects run -off from CRDA -2. The pond was dry during the inspection. Volume III, Appendix 13 -2, page CRDA2 -1 shows its design water and sediment capacities are 1.37 A -F and 1.23 A -F respectively. There are approximately 3.2 -feet of sediment buildup in the pond. This figure is derived from the average length of the two sediment poles located in the pond Water Sediment Total Pond 9 - A -F 0.66 0.15 0.81 SNOWCAP COAL COMPANY NORTH AND SOUTH PORTALS IMPOUNDMENT YEARLY INSPECTION In accordance with Rule 4.05.9(14), all impoundments shall be inspected at least yearly to determine if the impoundment has been maintained as designed, and in accordance with the approved plan and the applicable regulations. This yearly inspection is for the impoundments located at the North and South Portals and Refuse Disposal Areas. On March 15, 2012, I performed the required yearly inspections. I, J. E. Stover, have a wide variety of experience in the design and construction of earth fill embankments. Nothing was observed during the inspection that would indicate the ponds have a potential for failure. There was no appearance of erosion, instability, structural weakness or other hazardous conditions. There are no required monitoring procedures or instrumentation other than quarterly and yearly inspections. There are no aspects which might affect stability and there is no required maintenance. None of the pond /impoundments were discharging during the inspection. Pond 6 collects run-off from CRDA -1. The pond was dry during the inspection. There are approximately 2.3 -feet of sediment buildup in the pond. This figure is derived from the average length of the three sediment poles located in the pond minus the design depth. The percent of sediment buildup is 43% (2.3' deep divided by 5.4' maximum depth). Based on this sediment buildup and aerial topo maps, the pond has the following estimated capacity. The estimated water capacity of Pond 6 is less than the original design requirement of 1.49 acre feet. However, calculations presented in Volume III, Appendix 13 -2, page CDRA -1 -1 ii, based on the partially reclaimed and vegetated refuse pile indicate the required water capacity of Pond 6 is only 0.68 acre -feet. Pond 7 & 8 were reclaimed in 2011 Pond 9 collects run -off from the South Portal and RSRDA. The pond was dry during the inspection. Volume III, Appendix 13 -2, page RSS -15 & 15i shows that its design water and sediment capacities are 0.33 A -F and 0.33 A -F respectively. The sediment was removed from the pond during 2003 so the pond had a total depth of 9 -feet. Sediment (2.6) has accumulated in the pond since it was cleaned. The percent of sediment buildup is 60% (2.6' deep divided by 4.3' maximum depth). Based on this sediment buildup and a 2003 survey of the pond after sediment was removed, the pond has the following estimated capacity. Pond 10 collects run -off from CRDA -2. The pond was dry during the inspection. Volume III, Appendix 13 -2, page CRDA2 -1 shows its design water and sediment capacities are 1.37 A -F and 1.23 A -F respectively. There are approximately 3.2 -feet of sediment buildup in the pond. This figure is derived from the average length of the two sediment poles located in the pond Water Sediment Total Pond 6 - A -F 1.33 0.95 2.28 SNOWCAP COAL COMPANY NORTH AND SOUTH PORTALS IMPOUNDMENT YEARLY INSPECTION In accordance with Rule 4.05.9(14), all impoundments shall be inspected at least yearly to determine if the impoundment has been maintained as designed, and in accordance with the approved plan and the applicable regulations. This yearly inspection is for the impoundments located at the North and South Portals and Refuse Disposal Areas. On March 15, 2012, I performed the required yearly inspections. I, J. E. Stover, have a wide variety of experience in the design and construction of earth fill embankments. Nothing was observed during the inspection that would indicate the ponds have a potential for failure. There was no appearance of erosion, instability, structural weakness or other hazardous conditions. There are no required monitoring procedures or instrumentation other than quarterly and yearly inspections. There are no aspects which might affect stability and there is no required maintenance. None of the pond /impoundments were discharging during the inspection. Pond 6 collects run-off from CRDA -1. The pond was dry during the inspection. There are approximately 2.3 -feet of sediment buildup in the pond. This figure is derived from the average length of the three sediment poles located in the pond minus the design depth. The percent of sediment buildup is 43% (2.3' deep divided by 5.4' maximum depth). Based on this sediment buildup and aerial topo maps, the pond has the following estimated capacity. The estimated water capacity of Pond 6 is less than the original design requirement of 1.49 acre feet. However, calculations presented in Volume III, Appendix 13 -2, page CDRA -1 -1 ii, based on the partially reclaimed and vegetated refuse pile indicate the required water capacity of Pond 6 is only 0.68 acre -feet. Pond 7 & 8 were reclaimed in 2011 Pond 9 collects run -off from the South Portal and RSRDA. The pond was dry during the inspection. Volume III, Appendix 13 -2, page RSS -15 & 15i shows that its design water and sediment capacities are 0.33 A -F and 0.33 A -F respectively. The sediment was removed from the pond during 2003 so the pond had a total depth of 9 -feet. Sediment (2.6) has accumulated in the pond since it was cleaned. The percent of sediment buildup is 60% (2.6' deep divided by 4.3' maximum depth). Based on this sediment buildup and a 2003 survey of the pond after sediment was removed, the pond has the following estimated capacity. Pond 10 collects run -off from CRDA -2. The pond was dry during the inspection. Volume III, Appendix 13 -2, page CRDA2 -1 shows its design water and sediment capacities are 1.37 A -F and 1.23 A -F respectively. There are approximately 3.2 -feet of sediment buildup in the pond. This figure is derived from the average length of the two sediment poles located in the pond