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recovery was less than originally projected in portions of the original (pre-PR-5) permit area, due <br />to discrepancies found in the Peabody topsoil depth estimates. A mitigation plan was approved <br />by the Division and implemented by the mine in 1996. <br />Whenever possible, topsoil is live hauled to active reclamation areas. However, this cannot <br />always be accomplished (particularly in the case of acreage designated as Prime Farmland), and <br />some topsoil will be stockpiled. Stockpiled topsoil will be protected from wind and water <br />erosion by roughening and ditching around the pile, establishing an annual cover crop, or <br />establishing a perennial grass cover, depending on the length of time a stockpile will be in place. <br />Excavation is performed by dozers, trucks and shovel. The anticipated mining schedule for each <br />area where mining will occur is graphically shown on Map 2.05.3-1 in the permit document. <br />Overburden is removed by a shovel and trucks after an area has been drilled and shot. An ANFO <br />slurry is the primary agent used in tine blast. All shots are monitored with seismographs located <br />at structures nearest to the blast. Blasting schedules are published in the local newspaper. Most <br />blasting occurs mid-day early in the week. Daily notifications are made to certain individuals <br />that request this service prior to each blast. <br />The primary coal seam to be recovered is the Lower Dakota seam; however, the Upper Dakota <br />seam will be recovered if it is thick enough and of sufficient quality. Maximum overburden <br />depth will approach 120 feet. Excavations currently have a north-south orientation and will <br />progress westward for the remainder of the life of the mine. <br />Mining began along the eastern subcrop of the New Horizon Mine 2 area. A panel mining <br />method is used to develop the pits (see Map 2.05.2-1). The panels will vary in length, up to <br />3,500 feet. The panel width will typically be 100 to 120 feet. The mine will occasionally have <br />up to two pits actively working in order to effectively mine the two seams. Exhibit 2.05.3-1 <br />shows a typical cross section of the mining and reclamation plan. The overburden is excavated <br />using a shovel and trucks and then placed or pushed into an adjacent or nearby mined-out pit <br />panels, with the exception of the initial cut, which was placed adjacent to the pit onto land <br />designated as a temporary overburden stockpile (see Map 2.05.2-1). <br />During overburden removal operations, some selective handling of material will be performed <br />based on chemical and physical core data contained in Section 2.04.6, Geology Description, and <br />discussions presented in Section 2.05.4(2)(d), Topsoil (Redistribution) of the permit application. <br />Following recovery of the lower Dakota coal seam within the New Horizon Minel permit block, <br />the pit was backfilled to approximate original contour. Overburden was tested to ensure that acid <br />or toxic forming spoil was not placed within four feet of the surface. Topsoil was then replaced <br />in approximate thickness of 1.0 feet on dryland pastures and 1.5 feet on irrigated pastures, <br />dependent upon the actual amount of topsoil recovered. The areas were then seeded and <br />irrigated for pasture establishment. <br />At the New Horizon Mine 2 permit block, the sequence of coal recovery, backfilling, and <br />overburden testing is as described for the Mine 1 permit block. Soil stripping and replacement <br />practices have been revised a number of times subsequent to initiation of operations in 1992, <br />most recently by TR-57, approved in early 2009. In most areas, the thicker, higher quality <br />16