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Species Diversity Conclusions <br />The Division considers that adequate species diversity for the post-mining land use of rangeland has <br />been established based upon vegetation sampling conducted in July 2005 and June 2006. <br />The 2005 sampling observed perennial five species that met the required species composition with <br />greater than 3% relative cover. These species consisted of three grass species (Smooth brome, <br />Kentucky bluegrass and Western wheatgrass), one shrub species (Mountain big sagebrush); and one <br />forb species (common dandelion) consistent with a rangeland community. Other species that <br />support the post mining land use of rangeland were present but with lower relative cover. The <br />reclaimed area had been heavily grazed prior to sampling. None of the species with greater than 3% <br />relative cover were considered noxious species. <br />The 2006 sampling observed eight species that met the required species composition with greater <br />than 3% relative cover. These species consisted of five perennial grass species (Smooth brome, <br />Intermediate wheatgrass, Kentucky bluegrass, Western wheatgrass, and Sheep fescue), one shrub <br />species (Mountain big sagebrush), and two forb species (Silvery lupine and Western yarrow) <br />consistent with a rangeland community. The reclaimed area had been grazed prior to sampling. <br />None of the species with greater than 3% relative cover were considered noxious species. <br />Erosion Control and Sediment Yield <br />Established vegetative cover on the reclaimed pits appears to be sufficient for preventing rill and <br />gully formation. No significant rilling or gullying was encountered during the termination of <br />jurisdiction inspection of November 8, 2007. Contour furrows are still in evidence on the reclaimed <br />pits. Short and shallow rills (no longer than the distance between furrows, and no more than four or <br />five inches in depth), were noted occasionally where water had breached a contour furrow. This <br />breach flow was caught by the next downslope furrow, keeping any rilling to a minimum. These <br />features were few and observed only on steeper slopes in reclaimed Pits 1 and 5. Some gullying was <br />observed on the remaining pit access roads in areas where runoff bypasses road ditches. Pond 5 <br />catches road runoff from Pits 1, 5 and 6 and associated access roads. <br />Soil loss rates derived from the Universal Soil Loss Equation (USLE) and the T factor were <br />compared. The USLE is the product of rainfall-runoff (R), soil erodibility (K), slope-length- <br />steepness (LS), cover-management (C), and erosion control practice (P). The T factor is an estimate <br />of the annual rate of soil erosion by wind or water that can occur over a sustained period of time <br />without affecting crop productivity, with T factor values calculated by the National Resource <br />Conservation Service. <br />For the Grassy Gap Mine, the following USLE factors were used: <br />R = 30 [Figure 1, SCS Agronomy Note #50 re. #2, August 1982] <br />K = 0.24 [Figure 3, SCS Agronomy Note #50 re. #2, August 1982 & <br />http://websoilsurvey.nres.usda. gov/app/WebSoilSurvey.aspx] <br />LS = 2.4 [Table 2, SCS Agronomy Note #50 re. #2, August 1982. Grassy Gap Permit, <br />Reclaimed Topography Map (1990). Slope gradient was determined for each <br />pit, then averaged. An average slope length value of 300 feet was used.] <br />Grassy Gap TOJ 6/5/2009 15