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CNAPTERFOUR Environmental Consequences acres of fragile soils (5 percent of the study azea). Incremental disturbance of the mine panels would affect 470 acres of fzagile soils (12 percent of the study area) over 30 yeazs. Project facilities would disturb 35.2 acres of fragile soils (less than 1 percent of the study area) for the ' life of the project. Some soil loss to wind and water erosion is inevitable. However, minimizing the disturbance azea, retaining a vegetative cover over much of the Piceance Site, and effectively using erosion ' and sediment control structures (i.e., silt fencing, straw or hay check dams and filters, erosion blankets or mats, water bars etc.) at all disturbed sites would reduce the potential for accelerated ' erosion and sedimentation. Studies have shown that most accelerated erosion occurs in the first year following soil disturbance and that measures such a mulching can reduce erosion by as much as 60 to 80 percent in that critical fast year (Ketcheson and Megahan 1996; USFS 1979; ' Synthetic Industries 1996). Interim or final revegetation with a protective herbaceous cover could be expected within one to two years for most areas. Upon successful revegetation, erosion rates could be expected to return ' to rates similar to existing conditions for the long term. Revegetation may be more difficult in areas with high rock content and for shallow soils on steep slopes, but use of erosion control ' measures, and monitoring and retreatment as needed, would likely return such sites to conditions similaz to predisturbance levels of erosion within 5 years. Severe, localized erosion impacts would be expected to occur in any azea of fragile soils where erosion control measures or revegetation efforts were not adequate. Loss of soil fertility and soil structure would occur during soil salvage and stockpiling. Although almost none of the soils within the proposed mine azea are well-suited for use during reclamation, salvage of what little coversoil is available would provide an important source of plant growth material to assist with reclamation. Stockpiled material would be protected from erosion, and a temporary vegetative cover would be established on stockpiles that would be inactive for more than 12 months. Following redistribution of coversoil material, and based on fertility testing, fertilizers or other soil amendments would be applied as needed, which would increase the potential for successful reclamation. Other measures such as erosion control and ,application of organic mulches would also aid in re-initiation of the soil development process. Biological activity in soils would gradually increase after reclamation, and plant communities and soil structure would evolve on reclaimed azeas. Natural Gas Piveline Alternative A Construction of this alternative would result in temporary disturbance of 1.2 acres of fragile soils. Impacts, mitigation and reclamation would be as described above. Natural Gas Piveline Alternative B Construction of this alternative would not result in any impacts to soils in addition to those described above. ' Soils 4-7