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Slope <br />(Construction Materials Rule 3.1.5 (1), (3)) <br />The natural land form and dip slopes in the surrounding area can be <br />considerably greater then a 33% slope (Map 5 and 7, Photo 2). The <br />classifications of the soils on the pit also indicate a natural slope of 25-75% <br />(Schroeder, 2004). Using the 10 m DEM and converting to represent slope <br />shows a fair amount of areas with slopes over 3/1 along the same geologic <br />features that stretches to the east and west. Map 5 details the natural slope <br />derived from the 10m DEM (Appendix E, Map E3). The 1995 land survey was <br />used to estimate the slopes of the north side hill and the westerly portion <br />with the steepest area averaging 2.5/1 and ranges from 1.1/1 - 3.1/1. Since <br />this portion has never been mined it is assumed that this is a representation <br />of the natural land form (Appendix E, Map E5). While a slope of 33% or less <br />is advantageous for stability or re -vegetation, it may not be physically <br />possible (e.g. bedrock, Photo 8) nor in keeping with the surrounding land <br />form (See Map 5-7 and Appendix Q. We quote from the Construction <br />Materials Rule 3.1.5 (2006), "Maximum slopes and slope combinations shall <br />be compatible with the configuration of surrounding conditions..." Thus we <br />suggest that during mining of product and removal of overburden, the final <br />contour is considered in keeping with the surrounding land form. For <br />example, using a dozer to move material from the top to the bottom of the <br />slope may prevent undercutting and destabilization of the hill and help <br />maintain a shallower slope (mining in a downhill direction). It is also <br />suggested that when a slope greater than 2.5/1 cannot be reduced due to <br />bedrock (without blasting), or constraints by land form, that the overall <br />height should be reduced or the toe portion buttressed if possible (or both). <br />This was the approach in the 2016-17 reclamation area leaving 0.25 acres <br />with slopes ranging from 0.9 to 1.6. <br />See Appendix A for further suggestions and recommendations on soils and <br />contouring. <br />----- 30 1 Page <br />left.1'(JI'VLLLk-R-%VILIII RAIMAI <br />E:Y { .kLA I' BASIN HNA- IW")N\II N I AI MINI] M -!l I.\ I I( 5 - WIVIN. (, R I A I R NSI N1 1,V 1 LO \d <br />