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pre-mining topography for the Pond 010 drainage basin consists of a gently west-sloping, well- <br />. grassed surface of about 3,300 ft feet that exhibits excellent sediment control characteristics. <br />The mine plan calls for anorth-south oriented pit that moves westward from 27.00 Rd. Since <br />typically the mine strips topsoil from one to three pit widths (115 ft to 345ft) ahead of the pit at any <br />one time, the actual area needing storm sediment protection will be much less than the area <br />calculated for Ponds 010. In addition, because WFC will use contour ditches to collect run-off from <br />a significant portion of the area of topsoil removal and direct the storm flow into the pit, the actual <br />proposed for the SAE is estimated to vary from about 2.82 acres in 2003 to about 11.67 acres in <br />2008. Map Att 2.05.3(3)7-1 shows the surface area disturbed by topsoil removal from year 2003 to <br />2008, the general location of the contour ditches and sediment control ponds(discussed below), <br />and the acres up and downgradient of the contour ditch for each year. To the east of the topsoil <br />stripping area will be the coal extraction pit. The west edge of this pit will be the east limit of the <br />disturbed topsoil area that would drain westward. East of the west edge of the pit, the pit itself will <br />act as a gigantic "sediment" pond for any overland storm water flow from the mine spoil areas or <br />from reclaimed land. So, the only area needing storm water protection will be the migrating area <br />stripped of topsoil in advance of the coal extraction pit. For the smaller watersheds that drain into <br />Tuttle Draw, sediment control Ponds such as 012 and 013 will be built as needed in the normal <br />course of mining. ~. , <br />For sediment control in the proposed "Traveling" Pond W FC will use contour ditches to collect run- <br />off from a significant portion of the area of topsoil removal and direct the storm flow into the pit. For <br />the areas down gradient of the contour ditches, small incised, non-discharging, sediment control <br />ponds sufficient for the calculated run-off volume of the disturbed area will be excavated at either: <br />1) the downstream edge of each annual topsoil strip area, or 2) a single pond sized for the largest <br />annual disturbance will be located at the downstream edge of the estimated year 2008 disturbed <br />area. These ponds will be excavated by mine equipment, and their complete placement in native <br />earth plus non-discharging nature precludes an engineering design other than the need for <br />adequate volume. In addition (but not limited to), a number of staggered contour catchment v- <br />ditches (approximately 12 inches deep) will be plowed along the length of the topsoil removal area <br />within the SAE to catch runoff and keep the water from gathering volume. Intermediate scarifying <br />groves of approximately 6-9 inches deep would also be plowed in to further allow infiltration of <br />surface water runoff into the earth, rather than allowing it to collect and run cross country. <br />• (Revised ~/zoos) 2.05.3(3) - 20 <br />