2016-12-23_PERMIT FILE - C1982056A (3)

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2,500 feet upstream of the crossing. An instantaneous peak flow of 65 cfs was recorded on May 5, 1996. The recording period for station 800 is 1976 to 1996. An additional culvert run was performed with SEDCAD+ for the instantaneous peak flow of 65 cfs. Headwater depth for this run was based on the design roadway elevation of 6.5 feet above the invert of the culvert. A 36 -inch culvert will safely pass the highest recorded instantaneous peak flow with the additional headwater depth provided by the roadway embankment. In order to assure additional capacity for potential blockage, a 70 -foot, 42 -inch CMP, or up to a 48 -inch CMP, was installed at the crossing. Slope protection is provided on both the upstream and downstream sides of the crossing using rock rip -rap. Drainage from the road surface flows along the ditch line provided by the safety berm. Rock filters or other sediment control measures are constructed at locations where road drainage flows into the creek as necessary. Drainage from the Batch Weigh/Loadout area is currently directed along the railroad tracks to Foidel Creek. The road on the west side of Foidel Creek is located in a previously disturbed old roadbed, therefore topsoil was not available for salvage. The road on the east side of Foidel Creek is constructed along the toe of Pond C, which is also in a previously disturbed area. On the east side of Foidel Creek, limited quantities of topsoil are available for use in final reclamation. The topsoil was windrowed to the side or placed in a stockpile adjacent to the road. Minor grading was done in the road corridor to provide a satisfactory base for subsequent road construction. A structural geo-grid material was placed above geo-fabric to distribute loads over the soft soils more uniformly and reduce the required thickness of fill material required which, in turn, reduces the overall footprint of the roadway. Openings in the geo-grid structure are approximately 1 inch by 1 inch. The fill material locks into these openings and increase the structural stability of the sub -grade. Safety berms were constructed on either side of the roadway. The berms are constructed of spoils materials from the mine site. This spoils material has been used extensively on the mine site in the past as fill material and is not acid -producing. During construction, temporary erosion control measures were implemented as necessary. Long-term erosion protection is provided by seeding the outslopes with an appropriate seed mix and use of selectively placed rock check dams. Mulching, fiber mats, topsoil, or other appropriate medium for the establishment of plant growth may be applied, as necessary, to assure adequate vegetative establishment. Affected wetlands areas will be revegetated with vegetation native to the area as determined in project wetlands delineations. The total area of wetlands disturbed by this project is approximately 0.01 acres. Upon reclamation of this roadway, TCC will seed a wetlands area of at least 0.10 acres to satisfy the U.S. Fish and Wildlife's request for a 2:1 mitigation of wetlands area disturbed by the crossing. HwIroad Modifications for Sage Creek Coal Haul f M2-80 As development of the Peabody Sage Creek Mine (PSCM) proceeds, the coal generated from the ongoing mine development and subsequent future mining activities will be stockpiled at the Sage Creek site, loaded onto highway trucks, and transported to the Foidel Creek Mine facilities for processing through the existing washplant and loading into trucks or rail -cars for shipment. As production from the Foidel Creek Mine declines in future years, production from the PSCM is expected to increase, with a maximum of approximately 8.0 million tons of raw coal being transported from Sage Creek to the Foidel Creek Mine Facilities. Overall production and throughput for the Foidel Creek Mine Facilities is not expected to exceed the currently permitted annual level of 12.0 million tons. In order to minimize incremental disturbance, and handle the additional anticipated truck traffic from Sage Creek safely and efficiently, TC plans to utilize the existing Foidel Creek Mine road network, with a number of minor road and drainage modifications, to increase road widths and capacities and address safety considerations associated with the anticipated increase in traffic levels, as shown on the Mine Facilities Map (Map 24). With the exceptions of the Main Entrance Access/Haulroad, most of the Refuse Haulroad, and the Batchweigh/Loadout Haulroad, all other mine haulroads will be modified and utilized for the Sage Creek coal haul. Normally, the Sage Creek coal haul will enter the Foidel Creek Mine Facilities at the West Mine Entrance, proceeding on Haulroad A to the Haulroad C intersection, the coal haul will continue on Haulroads C, B-2, and the Haulroad B Driveway to a truck dump at the ROM Coal Stockpile. The empty coal tricks will proceed from the ROM Pile to the west on a portion of the Refuse Haulroad, the Haulroad B-1 Extension, and Haulroad B-1, connecting back to Haulroad A, exiting the Foidel Creek Mine Facilities at the West Entrance, and returning to Sage Creek on RCR27. If the intersection of Haulroads C and B-2 is blocked by a TR12-80 2.05-72 11/07/12