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<br />Proposed Decision and Findings of Compliance July 2018 <br />Permit Renewal No. 7 P a g e | 47 <br />Drainages in the South Taylor Pit are constructed with gradients similar to those originally present, <br />and complement the drainage pattern of the surrounding terrain. Pre-mining and post-mining <br />drainage profiles are found on Map 33B of the PAP. <br /> <br />Final grading plans for the South Taylor Pit provide a surface that both minimizes erosion and <br />slippage following the placement of topsoil. Final slopes, in general, do not exceed one vertical to <br />three horizontal (1v:3h). <br /> <br />The Collom area to be mined will be restored to a topography approximating pre-mining grades. <br />The slopes of backfilled areas, as necessary, will utilize contour furrows for erosion control and <br />stability. Final grading plans for the Collom pit will be conducted in a manner that minimizes <br />erosion and provides a surface for topsoil that minimizes slippage. Final grading will be <br />accomplished that overall grades will not exceed 1v:3h. Backfill and grading for the Collom Pit <br />is shown on Maps 19C and 29B of the PAP. <br />D. Specific Findings Required by Section 4.14 <br /> <br />The following specific findings are applicable to all areas of the Mine including the East Pit, West <br />Pit, Section 16 Pit, South Taylor Pit and Collom Pit. <br /> <br />1. The Division approved the retention of box cut spoil or initial cut spoil outside the pit area since <br />Colowyo has demonstrated that such material is not required to achieve approximate original <br />contour in accordance with Rule 4.09.1 (Rule 4.14.1(2)(d)). <br /> <br />2. Colowyo demonstrated that fill proposed to eliminate the highwall and depressions meets all <br />the requirements of 4.05, 4.06, 4.09 and 4.15. Therefore, the Division proposes that excess <br />material not required for reclaiming highwalls and other depressions need not be returned to <br />approximate original contour (Rule 4.14.1(2)(a)). <br /> <br />3. In order to conserve soil moisture, ensure stability, and control erosion on final graded slopes, <br />the Division approved cut-and-fill terraces. These terraces are compatible with the post-mining <br />land use, and will meet all the requirements of Rule 4.14.2(2). <br /> <br />4. Permitted small depressions (less than two acre-foot in capacity, embankments less than five- <br />feet) in the backfill are used to minimize erosion, create or enhance wildlife habitat, conserve soil <br />moisture, and promote revegetation. The Division specifically approves each such small <br />depression (Rule 4.14.2(3)). <br /> <br />5. The Division approved Colowyo’s plan for disposal of debris, acid-forming or toxic materials, <br />or materials constituting a fire hazard in a manner designed to prevent contamination of ground or <br />surface waters. A contingency plan has also been developed to prevent sustained combustion of <br />flammable materials (Rule 4.14.3(1)(a)). <br /> <br />6. The Division approved the method and design specifications for covering of acid-and