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Pit dewatering will be primarily a seasonal occurrence. The dewatering process will be a <br />sporadic, operation -controlled occurrence depending on various factors which may include the <br />location of the pit inflows, the location of standing water in the pit, or the location within the pit <br />of the overburden and coal removal operations. When pit dewatering is required, the anticipated <br />dewatering rate will be in the range of one to two cubic feet per second or less. Direct pit <br />pumping into Pond NHN-001 or NHN-002 is planned for the mining south of Meehan Draw and <br />into Pond NHN-003 for the mining north of Meehan Draw. Actual water flow velocity going into <br />ponds will be controlled with adequate erosion control (i.e., rock riprap, geotextiles, synthetic <br />liner, half -culverts, etc.) or discharged onto non -erodible bedrock material. This will minimize <br />erosion of the pond banks. <br />Pit dewatering will have an insignificant impact on the ponds. Pit dewatering will be sporadic <br />versus continuous. The flow rate of one to two cubic feet per second or less compared to the <br />designed 10 -year, 24-hour peak inflow rate the ponds were designed for is relatively <br />insignificant. Furthermore, all discharge from the ponds will be in accordance with applicable <br />discharge permits. <br />Monitoring for rills and gullies on the pond and other reclaimed slopes will be carried out on a <br />periodic basis; the monitoring being geared to those periods after spring snow melt and during <br />required quarterly pond inspections. <br />Occurrence of excessive rills and gullies will result in implementation of the following plan. <br />One of, or a combination of, the following options and corrective methods will be employed: <br />If it is determined that the topography of the regraded area is such that drainage is concentrated <br />in a particular area, then this area will be improved to accept the runoff. In areas where no <br />natural armoring is present, the drainage bottom or channel will be reshaped, if needed. The <br />channel bottom will be seeded, covered with erosion matting and seeded, or rip -rapped. The <br />method used will, of course, depend on site conditions. Continued observations will be made of <br />this area for problems or necessary maintenance. On slopes where no swale or defined channel <br />exists, regrading, or disking, or chisel plowing will be performed, depending on the extent of the <br />erosion. Reseeding will then take place. <br />In addition to the above, contour furrows in and above the erosion area may be constructed to <br />trap and slow down the runoff. Straw dikes can also be used where appropriate to control runoff <br />and promote revegetation. <br />If corrective measures described above fail, WFC proposes to observe and reevaluate the <br />situation. A combination of the first two methods described or some variation therein will be <br />applied. These activities can include, but are not limited to, rock channels, contour furrows or <br />Section 2.05.3(4) Page 5 Sept. 2015 (TR -11) <br />