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That said, the methods of reclamation described above for future stepped highwalls which <br /> would undoubtedly be used here should still apply quite nicely. However, the lines of stepped walls <br /> may be very different here and may be curved as the margin of the silt pocket is slowly uncovered <br /> strip by strip. It is still true that if this area is mined and it turns out that all of it is good, then all of it <br /> will still end up with a north-south oriented, stepped wall along the western edge. And that will <br /> become a 3:1 slope with reclamation. If not then the reclamation slope will need to curve around the <br /> outside of whatever portion of the assumed silt pocket there actually is that is not worth mining. <br /> Drainage Control <br /> No ponds or lakes will remain after reclamation. Any exposed groundwater will be eliminated. <br /> As the general slope will be about 1%to the south, drainage of surface water that accumulates during <br /> rain storms will be gentle and to the south. <br /> But what if the amount of precipitation is so great that the gravel floor of the pit cannot absorb <br /> it quickly?That does happen once in awhile with very large thunderstorms. However, because the <br /> gravel floor is so porous it is uncommon that any ponding occurs that lasts for more than two or three <br /> days. <br /> Because the surface flow path to the south down the gentle slope of the floor is always blocked <br /> by a highwall during mining,runoff cannot go anywhere except into the underlying gravel layer that <br /> sits on top of the Pierre Shale. Plus,because the operation is in a pit bounded on all sides by walls no <br /> water can leave the interior of the mining operation. Sediment in the water simply drops out as the <br /> water percolates into the ground. There are no water outlets from the pit to any place outside of the pit <br /> such as drainages. <br /> However, at the end of the operation no blocking highwall may remain and instead designed <br /> drainage facilities will be installed. As described in the portion dealing with the "Final Configuration <br /> of the South End" of the mined area, decisions as to what will be best at that time will need to be <br /> determined at the time the mining reaches this area and it can be determined what, if any, mining will <br /> be done. It may be necessary to modify the permit at that time. Several options are possible. It is also <br /> possible the most southerly part of the permit may not be mined at all and mining will stop at the top <br /> of the steeper slope that descends into the valley to the south. <br /> Fountain Pit Technical Revision#3 - June 2022 M-1982-155 Reclamation Plan Page 16 of 23 <br />