Laserfiche WebLink
Logan Wash Mine TR No. 4 <br />composition, and south-facing aspect. The original Plan calls for the establishment of <br />"biological islands" on the dump slope. No top soil was to be added to the slope. The biological <br />islands were to be created by transplanting tubelings of shrubs and the "hydraulic planting" of <br />grasses and fortis. A Weyerhauser Silva-Fiber was to be used to during the hydro-mulching <br />process. The hydro-mulch was to be applied directly to the dump slopes. <br />OOSI has reassessed reclamation of the mine dump slopes. Given the steep slopes and <br />occasional high winds experienced at the mine site, it is very unlikely that an applied hydro- <br />mulch application will adhere to the steep dump face for the time required to establish <br />germination and plant growth. Even after initial root development, high intensity storm events <br />and normal rock fall events would remove much of the seed and young vegetation on this slope. <br />OOSI has formulated and initiated a more reliable approach to establishing vegetated islands on <br />the dump slopes. This approach involves the construction of hand-dug terraces on the mine <br />dump face. Terraces provide a flat surface that mitigates runoff of precipitation; a higher <br />percentage of precipitation should remain in place and provide plants with much-needed <br />moisture. Terraces will be installed where the waste rock material has a sufficient component of <br />fine soil-like material to support vegetation. To prepare for terrace construction, OOSI has spent <br />a significant amount of time removing metal trash and debris from the dump face. The <br />constructed terraces are small; about 18-inches wide and IS to 35 feet (ft) long. Silt fence is <br />installed on the headwall of each terrace to maintain terrace integrity. The terraces are spaced 6 <br />to 10 ft vertically and vary from 10 or more feet apart horizontally. Generally, the terraces are <br />constructed in groups. Each group of terraces will form the core of a vegetated island. <br />Although hand-sowing seed into the terraces was the preferred option, time constraints with the <br />approaching fall planting season will not allow this approach. OOSI therefore proposes to <br />hydro-seed the terraces. Because of the terraces' flat surface, impact from wind and runoff is <br />expected to be significantly less than the adjacent slope face, thereby providing a better <br />environment for hydro-seed materials. In addition, the hydro-seeding application will be <br />relatively fast and cost effective as the potential negative impact to adjacent terraces from <br />rockfall while on the slope face will be reduced because of less time spent on the slope face <br />while seeding as compared to hand planting. An organic fertilizer (Biosol®) and tackifier <br />(Guazdian®) will be used to improve seed germination and adherence to the terrace surface. <br />The hydro-mulch mixture for the slope terraces will consist of the following materials: <br />Slope Reclamation Materials <br /> <br />Material Application Rate <br />lbs er acre <br />Mat fiber h dro-mulch 2,500 <br />Guardian® (tackifier) 110 <br />Biosol® 1,500 <br />Humate 500 <br />Seed Mix (Table 1) 17.5 <br />Western Water & Land, Inc. <br />