2008-10-07_PERMIT FILE - C1981047 (4)

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• The applicant has contacted OSM, BLM and USFS. The comments made in the permit application on mitigation aspects are acceptable to those three agencies. 2.05.6 (3) Protection of Hydrolggic Balance The quality of the water in and around the Blue Ribbon Mine is affected by surface runoff. Prior to the mine being reclaimed in 1986, disturbed areas which may have contributed both dissolved and suspended solids to runoff and which may have otherwise affected water quality are: the highwall above the portals, the portal bench (including the upper coal storage area and the shop area), the bench outslope, the mine access road, and the lower material and coal storage areas. The chemical constituents in natural runoff originate from the weathering process. in humid climates, precipitation is most likely to leach out soluble salts as rapidly as they are formed. However, such is not the case in an arid to semi-arid climate as presently exists in the Hubbard Creek area. In addition, much of the soil in this area has been derived from Mancos Shale and Rollins Sandstone of the Mesaverde Group (Dunrud, 1976). These sedimentary rocks commonly contain substantial amounts of soluble salts (McWhorter et al, 1975). in dry climates, salts in soils derived from these sedimentary formations generally remain inadequately leached, except in the top layers of the soil profile. Mine waste disposal exposes fresh surfaces of saline shales and sandstone for leaching by rainfall • and snowmelt, thus influencing the quality of surface and subsurface runoff. Recent work has shown this to be the case in the Rocky Mountain region. Such complex factors as weathering, microbial activity, acid formation, cation exchange, capacity and nonequilibrium chemical reactions, to name a few, all influence the water pollution potential of mine spoils. Moreover, the salt pickup rate also depends heavily upon the local hydrology. Precise estimation of the total quantities of soluble salts that was generated from the Blue Ribbon mining operation is beyond the scope of this study and, for that matter, the state of the art. However, recent work by McWhorter and Rowe (1976) suggests that total salt pickup can be estimated from saturated spoil analyses and a knowledge of the local hydrology of mine waste disposal area. With further development, such a model would provide a method of evaluating the impacts of mine waste disposal on water quality. For the present, however, we must rely on a small data base for predicting impacts. 120 (Rev. 12-16-92)