2014-11-17_PERMIT FILE - C1982056A (3)

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A maximum of approximately 1.0 million cubic yards of un- compacted refuse was previously permitted to be temporarily stockpiled in a surge pile at the south end of the refuse area on an area where the topsoil has been removed. Actual maximum__ placement in this area has been approximately_400,000_ cubic yards and this volume • has been reduced to approximately 80,000 cubic yards by dozing stockpiled material to an adjacent permanent refuse disposal area. Once the remaining stockpiled material is removed and placed in permanent disposal areas, TCC has no future plans to utilize this area for temporary stockpiling (other than the temporary winter stockpiling, as discussed below). Stockpiled materials are transferred, placed, and compacted on active portions of the refuse area. As the stockpiled material is moved and placed, during the summer construction season, any underlying spoil/sub -soil material will be recovered and placed on available completed refuse pile bench areas. During the winter, up to 300,000 cubic yards of material may be tail- dumped on active portions of the refuse pile for temporary storage. In the spring, once any frozen materials are thawed so that effective compaction can be achieved, the piles will be spread and compacted as the next lift on the active pile area(s). The pile will be constructed in 50 -foot benches, as originally planned, and drainage will be established off of the pile as presented in Exhibit 26A. 2) Vertical Construction — This segment has been clarified to remove the requirement to construct "A" and `B" segments as proposed in Exhibit 26A. The recommendation presented in Exhibit 26A -1 to compact the entire lift as one unit without dividing it into segments will be followed. This will increase the stability of the fill by removing the potential for establishing a slip plane between segments A & B. As noted in Exhibit 26A -1, the two - segment construction was for "zoned construction" and this is not required for smaller piles. 3) Temporary Road Construction — The temporary road within the CRDA footprint will be filled in with refuse material, as per. the recommendation in Exhibit 26A -1, when it is no longer required. The recommendation includes benching and tying in with existing refuse pile to the north and south of this road. Final refuse placement activities in this area will require recovery and temporary stockpiling of clay cover materials in a nearby placement area, as shown on Exhibit 26A -1 -M1. The temporary clay stockpile will be placed on an existing permanent excess overburden stockpile. A short segment of the existing light -use road (designated a permanent postmining road in •Permit C -81 -071) will be widened to approximately 30 feet to accommodate two -way scraper traffic. Soil material will be stripped and stockpiled from stockpile and haulage areas prior to disturbance, and drainage control will be addressed by existing collection ditches and bench terraces on the excess spoil pile, which will route all drainage to the existing Sedimentation Pond D. The existing collection ditches and bench terraces, described in Exhibit 29, Draiange Control, and Exhibit 9, Excess Spoil, of Permit C -81 -071 as follows, were designed to effectively collect and convey all surface drainage from the excess overburden stockpile. Exhibit 29 (pg. Ex 29 -36) — "The drainage systems on top of the excess spoil structures are described in detail in Exhibit 9, Excess Spoil, and consist of maintaining a gradient that will prevent the impoundment of water on the spoil, thereby minimizing possible leaching. These drainage systems will transmit water off the spoil in a manner that prevents erosion and TSS loading of surface water. This will be accomplished by maintaining an even and consistent gradient and by installing riprap or other energy dissipaters where necessary. All drainage from the surface of the spoil will be diverted away from the outslope of the fill. Exhibit 9, page 27, Recommendation No. 11 addresses the drainage system on the top of the excess spoil piles. The intent of the recommendation is that the point of intersection of the outslope with the top of the fill be the highest portion of the excess spoil pile. As a result of the recommendation that the central portion of the fill be overbuilt approximately 5 percent, the water collecting on the top surface of the fill will flow to the edge of the fill and down the permanent diversion ditch. Exhibit 9 (pg. 27) — 8. We recommend that diversion ditches be constructed around and uphill of all disposal areas. For Area 1, it appears that the most effective method would be to have a horseshoe - shaped drainage system with a high point near the highest elevation of the fill, with drainage occurring on the north side and the south side of the fill in natural materials. The drainage ditch on the south side of the fill should be substantially larger than on the north side to intercept drainage which might occur from the slope above the fill. • MR 10 -251 2.05 -97.1 05/27/11