2014-04-25_PERMIT FILE - C1982056A (3)

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The tunnel also includes a 36 -inch buried corrugated steel pipe escape tube extending from the tunnel approximately 50 feet to the south. One cubic yard of concrete was required at the point where the escape tube daylights. A 150 -foot long 3-6-inch-conveyor extends from within the tunnel to discharge directly into the stoker •trucks. Two cubic yards of concrete were required for a pad to support the conveyor structure. An MCC building was constructed near the escape tube exit. Dimensions of this building are approximately 15 x 15 feet, with a concrete floor requiring approximately 2 cubic yards of concrete. A retaining wall was constructed on the north side of the existing pile. The wall required 6 steel piles driven to a depth of 25 feet, with treated wood cribs placed between the piles to form the wall. On completion, this wall was approximately 50 feet long and up to 12 feet high. Haulroad B -2 was widened by approximately 20 feet to allow for a loading area with room for traffic to pass trucks that are loading. The emergency spillway elevation of Pond E was staked and the toe of the fill does not extend past this line, to assure that no storage capacity is lost. Topsoil was stripped, salvaged, and stockpiled on the topsoil stockpile east of Pond E where the haulroad widening extended below the west of the pond embankment. No construction occurred within a buffer zone of 100 feet from Foidel Creek. Silt fences, hay bales, rock filters, or a combination of these control measures were used, as required, to prevent sediment from washing into Foidel Creek from the new fill material or road section. Reclamation associated with these additions will occur when the Washplant facility is dismantled. The concrete will be broken up and disposed of on -site. The steel associated with these additions will be either salvaged or disposed of on -site. Stoker Coal Handling System Modifications (TR08 -65) With construction and commissioning of the new washplant (Washplant II) coal processing is shifting to the new, and more efficient, washplant. As a result, TCC proposes to construct and operate a stoker coal conveyor from the new washplant to the existing Stoker Coal Self - Loading System. The Washplant II Stoker Coal Conveyor will consist of a 50 -foot long, 30 -inch coal transfer conveyor, installed on the second level of the new washplant (feed chute -work was installed at the time of initial construction), a 190 -foot long, 30 -inch elevated • conveyor from the end of the transfer conveyor to top of the existing coal stoker stockpile, an 8 -foot wide elevated conveyor support truss structure with walkway, three conveyor bents on poured support piers, and the associated conveyor drive units and take -ups. The highest support bent will be approximately 65 feet high (drop - cables to support conveyor truss), and the conveyor discharge point will be approximately 40 feet above grade. Support piers will be drilled reinforced concrete piers, 36 inches in diameter and approximately 20 feet deep. Conveyors will have full covers for dust control. To facilitate more efficient truck movements and loading, the existing stoker reclaim conveyor will be extended approximately 20 feet, the truck loading area (includes a segment of Haulroad B -2) will be widened approximately 15 feet on the north side, and a 15 x 100 foot concrete pad will be poured under the loading chute. Extension of the reclaim conveyor and widening of the truck loading area will allow trucks to load and complete a full circle turn in the loading area, eliminating operational and safety concerns associated with truck backing and re- positioning in the loading area. Widening of the truck loading area will require soil material recovery from the expansion foot -print (approximately 120 cubic yards to Stockpile PPSP -1), relocation of one powerpole, and expansion of the existing engineered road fill to the north (approximately 1,800 cubic yards of compacted suitable fill), encroaching on the existing Foidel Creek stream buffer zone variance area. This minor incremental disturbance will not cause or contribute to violation of water quality standards or adversely impact water quality or quantity in Foidel Creek. The proposed Stoker Coal Handling System modifications are shown on Map 24 (Sheet 1 of 3) and by the design drawings provided in Exhibit 49K. Prior to, during, and following vegetative stabilization of the extended road fills, ASC's, consisting of silt fencing or straw wattles, will be installed and maintained along the toe of the extended fills to minimize erosion and help keep sediment out of Foidel Creek. The fill outslope and crest will be stabilized by seeding with the Pastureland Seed Mixture. As previously described, reclamation of the Stoker Coal Handling Modifications will • occur when the Washplant facility is dismantled. Equipment and steel will be either salvaged or disposed of on- site, and concrete piers will be broken up and disposed of on -site. MR 10 -251 2.05.32 05/27/11