2009-08-13_PERMIT FILE - C1981019A (3)

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and if necessary, after an area has been seeded. Given recent changes to Federal legislation (30 C.F.R. §816.22(d)(1)(i)) as published in the Federal Register (August 30, 2006, - pages 51683 - 51706), mine operators are now allowed to use "non-uniform redistribution of topsoil in their reclamation plan to encourage plant diversity...." Furthermore, the Colorado Division of Wildlife has requested Colowyo replace topsoil in a non-uniform manner as indicated by their statement: (see complete CDOW letter in Section 4.15.8) "DWM Wangnild discussed the possibility of changing reclamation efforts in the new [South Taylor] permit area. Specific changes would ideally be focused on dramatically varying topsoil depths in an effort to mimic natural depths and thus provide more suitable environments for woody species establishment. One example of this would be to create some sites with extremely shallow topsoil designed at reducing grass stand establishment and their resulting competition with shrubs for water and soil nutrients. Another example would be to create other sites with extremely deep topsoil depths. These sites would ideally benefit woody species like aspen and chokecherry." In this regard, and depending on site-specific opportunities, Colowyo will utilize the planned post-mine topography (PMT) to help identify candidate (and prime candidate) areas for targeting Sagebrush Steppe post-mining communities. Key to this analysis will be considerations for the risk of erosion and for long-term stability. One such "threshold" value to be used for this analysis will be a slope break at 10% gradient. Slopes greater than 10% will be considered too risky to make attempts at targeting shrub communities, largely due to snowpack runoff scenarios that can often lead to serious erosion and stability failures. For example, snowmelt runoff in the early 1980s caused widespread and severe down-cutting of the natural drainages to the immediate west of Colowyo. Unless proven otherwise by hydraulic and/or erosion modeling, slopes less than 10% will be identified as candidate locations for shrub community establishment. Another "threshold" value to be used in the PMT analysis is the size of units that may exhibit slopes 10% or flatter. Areas small in aerial extent (e.g., less than about 5 acres) will not be identified to receive shrub-conducive metrics. Only those areas that are larger will be identified. The exact size cutoff will be at the discretion of the reclamation coordinator, however, a practical limitation must be defined given the complications realized by the change in revegetation targeting measures. Where Sagebrush Steppe revegetation will be targeted, Colowyo would apply shallow lifts of topsoil (< 8 inches, ideally 4-6 inches). Where ideal spoil conditions are encountered, special effort will be made to place very minimal topsoil layers (nearly zero). The size of these areas must be small in order to ensure the potential erosion potential created by this activity does not negatively impact areas down slope. It is imperative for the Division to grant a substantial amount of latitude to Colowyo in the first several years of the implementation of the new reclamation plan as this will be a learning process for all parties involved. The Division will be informed of any instances of "nearly zero" topsoil laydown areas prior to or during topsoil laydown activities to ensure that the Division has the opportunity to verify Colowyo is adequately managing erosive potential. In most cases, due to the general rockiness of Colowyo's spoil, a layer of topsoil is desirable in order to limit damage to the preferred seeding equipment that will be utilized wherever possible in these areas, as proper seed depth placement is a major factor when establishing shrubs. To help maintain topsoil replacement balances, thicker lifts of topsoil (> 8 inches, occasionally up to 3-4 feet) can be placed along the groin of opposing slopes (drainage-ways). On long slopes steeper than 10%, topsoil distribution using pushdown 2.05-48 Revision Date: 3/14/08 Revision No.: TR-72