2012-10-04_REVISION - C1981022 (5)

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C- 1981 -022 PR -7 Findings October 4, 2012 the Division as appropriate (4.10.2(1)). 4. An alternative subdrainage system for the east yard coal mine waste area has been approved. The Division finds that such an alternative will ensure the applicable static factor of safety, stability of the fill, and protection of the surface and ground water (4.10.3(5)). VII. Backfilling and Grading The Division has approved a variance from meeting approximate original contour for reclaimed areas located at the lower Hubbard Creek area and at the Bear Creek facilities area (both areas are pre -law disturbance). The Division has approved a modification in the general grading requirements of 4.14.2 since sufficient spoil will not be available (4.14.2(1)). VIII. Reve etg ation Previously the Division had approved the use of introduced species in the reclamation seed mix. The seed mix was revised in TR -27 to include all native species. TR -40 revised the seed mix again to provide for additional forbs and woody plants to enhance overall stand diversity. Cicer milkvetch (a non - native species) was added to the mix and the grass component was modified by a reduction in overall seeding rate and increased diversity. Specific exceptions were made for some small disturbed areas on US Forest Service land. 2. The Division has approved the use of mulching with straw at the rate of 4,000 pounds per acre crimped in on slopes less than 3H: IV. On steeper slopes, hydromulch or straw held down with netting will be used as a means to meet soil stabilization requirements (4.15.4). Methods to measure herbaceous cover and production are discussed in Appendix H of the permit application. The methods follow those suggested in the DMG Bond Release Guideline, 1995. The Division has granted Oxbow Mining's request for the elimination of the woody stem density standard for the reclamation of the mine site. The Division has approved these techniques (4.15.7(1)). 4. Species diversity will be determined successful for bond release areas greater than 10 acres when at least four perennial species have a relative cover between 3% and 60 %. Of the four species at least one will be a forb or shrub, and applicable perennial grasses will be cool - season species. Species diversity for areas less than 10 acres will be determined successful when at least three perennial species will have a relative cover between 1% and 60 %. Of the three species, at least one will be a forb or shrub, and applicable grasses will be cool - season species. 28