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!" Somerset Mine - 3 - April 24, 1987 B. The culverts at the Elk Creek, Bear Creek and Hubbard Creek facilities will be removed during reclamation. The Division has not been provided with designs for riprap placement along the channel sideslopes following culvert removal. There are a total of 5 culverts totaling approximately 1,000 feet in length. Of major concern is the 670 foot culvert in the Elk Creek Yard Area. Information and cost estimates for culvert removal, channel construction, and riprap placement have not been provided. C. Sediment and drainage control plans during the reclamation phase are practically non-existant, Adequate plans must be submitted. D. Regrading plans are to be based on design criteria that wil] allow for long-term (greater than 10 years) stable slopes that will support a cover of suitable plant growth medium. Soil will not remain in place on a regraded slope that is at the angle of repose. If the soil sloughs, revegetation will fail and erosion will occur at an accerlerated rate. Regrading plans that allow for adequate revegetation success as well as long-term stability must be submitted for all areas. E. An erosion control plan needs to be developed for the regraded slopes. When bench outslopes and highwa115 are reduced, there may be 50~ slopes that are 300 feet long. Unless erosion controls such as contour furrows, contour trenches, or small basins are implemented there will undoubtedly be rill and gully problems. This is particularly true for the Elk Creek Yard Area - a 26 acre site on a south facing slope. F. Post-mining topography maps must be amended to ensure that regraded slopes compliment surrounding areas to the extent possible and that the post-mining topography is stable and capable of supporting a permanent vegetative cover. G. The mine was opened in 1902. At that time very little topsoil was salvaged during construction of the Somerset Mine facilities. The topsoil that was salvaged has been stored for at least a 5-10 year period. One would expect that the nutrient content and microbvial activity in the stored topsoil to be very low. Revegetation at the disturbed sites will occur on regraded subsoil or gob material with a thin covering of fair quality topsoil. Because of the soil conditions created during reclamation, various soil amendments will be needed for all regraded slopes. Soil amendments such as composted manure, wood chips, sewage sludge, or crimped mulch will help to build the post-mining soil. Without amendments, the post-mining soil will be very low in organic matter. The soil has to be developed first before the plants can grow successfully. The plants will then replenish the soil system through natural decay processes. Thus a soil conditioning or soil amendment plan must be incorporated into the overall reclamation plan to ensure reclamation requirements can be met.