2008-06-26_REVISION - C1981019 - Laserfiche WebLink

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• On long slopes steeper than 10%, topsoil distribution using pushdown techniques may be altered to facilitate thin layers near the upper shoulders of the slope, with thicker layers near the bottoms. • Another directive... (at the discretion of the field supervisor) will be instruction to equipment operators to NOT engineer the final surface, but to leave it in a state of disarray with thick and thin spots of topsoil. • Another... technique that may be used in ... Sagebrush Steppe would be the development of... topsoil "snow fence " berms. • The primary... element... is the ability to replace variable topsoil depths... depending on site-specific needs, the discretion of the field construction supervisor, and the capabilities (or lack thereofi of available materials and equipment. The only real commitments in the above (given the operator's use of "may" and "at the discretion of...") are that soil would be replaced in lifts less than 8 inches thick on ridgetops in grazingland areas, and gradually thicker moving down the slope; on sagebrush steppe, soil would be replaced in lifts less than 8 inches thick except along drainages, where thickness would be greater than 8 inches. The operator also included a list of practices that would not be implemented; specifically, topsoil would not be: • "buried in place" in the footprint of existing stockpiles. • placed without adequate metrics in place to accurately estimate volumes placed within each reclamation unit... • placed indiscriminately ... in a manner that does not serve a specific defendable purpose regarding vegetation type establishment... The amended plan is an improvement over the original proposal, but still does not provide the level of detail and commitment necessary to demonstrate compliance with regulatory requirements and land use/community type objectives. Additional details will need to be provided, to ensure that topsoil will be redistributed to achieve an approximate uniform, stable thickness consistent with postmining land uses and vegetation requirements, and to ensure ecologically significant variation in replacement thickness across the landscape. The value of significant (planned) variation in replacement thicknesses has been emphasized in discussions among the Division, DOW, and the operator since well prior to submittal of TR-72. Were the Division to approve the plan as presently laid out, it is not clear what the Division would be approving, except in the most general way (in some areas replacement thickness would be less than 8 inches thick and in other areas replacement thickness would be greater than 8 inches thick). The Division has given this matter considerable thought, and have come to the conclusion that, to be approvable, the plan will need to specify topsoil replacement thickness average and range for delineated or narratively defined