2025-04-08_PERMIT FILE - C1981019A

Home Browse Search

RULE 2 PERMITS Rule 2 Permits 2.05-18 Revision Date: 3/7/25 Revision No.: TR-166 Final grading before topsoil placement will be conducted in a manner that minimizes erosion and provides a surface for the topsoil that minimizes slippage. If spoil compaction is a problem, the spoil will be ripped with a dozer to minimize compaction, assure stability, and minimize slippage after topsoil replacement. Where possible, development of concave landforms (to encourage snow entrapment) will be developed. Where necessary, the overburden surface will be roughened by ripping or discing etc., to ensure a bond between the topsoil and spoil to reduce slippage. To date there is no evidence of topsoil slippage on reclaimed areas. A few small tension cracks resulting from settling of fill along tie in locations with highwall have occurred in a few areas. However, these areas within a year or two after reclamation, soon stabilize and begin to fill in. The final post mine surfaces are shown on Map 19, 19A, and 19B. Appropriate cross sections that show the anticipated final surface configuration of the reclaimed area, in conjunction with the existing pre-mining topography are shown Maps 20, 20A and 20B. Topsoil Redistribution Plan As discussed in Section 2.05.3, prior to any mining-related disturbances, all available topsoil will be removed from the site to be disturbed, and will be redistributed or stockpiled as necessary to satisfy the needs of the reclamation timetable described herein. The topsoil redistribution plan is also broken into three distinct timeframes which are pre-2005, 2005 to 2009, and post-2010. Each plan is described in more detail below. Pre-2005 and 2005-2009 Topsoil Redistribution Plan Prior to 2005, essentially all reclamation units were covered with an average of 18 inches of topsoil. From 2005 through 2009, reclamation areas received an approximate average of 8 inches of topsoil. 2010 - 2024 Topsoil Redistribution Plan A variable topsoil replacement plan was utilized at Colowyo from 2010 to 2024. This topsoil replacement plan targeted a variable depth replacement directly tied to the post mine land uses presented in Section 2.05.5, targeting the two rangeland components consisting of grazingland and wildlife habitat (sagebrush steppe). In the grazingland targeted areas (areas with slopes greater than 10%), topsoil was redistributed utilizing variable replacement depths. Thinner topsoil (approximately six inches) was replaced on ridge tops, and topsoil replacement depths gradually thickened moving down the slopes toward the drainage bottoms. In wildlife habitat (sagebrush steppe) targeted areas (flatter areas with less than 10% slopes), topsoil replacement depth was targeted an average of four inches, with a more uniform application depth which was attempting to encourage proper seeding depth and conditions for sagebrush establishment.