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- 16 - Two seeps were also located within the drainage of the proposed life-of-mine disposal area site. The water quality of both these seeps is typical of Mancos ground water, with a high content of sulfates and total dissolved solids (7DS). The Mancos Shale is generally considered to be a relatively impermeable rock unit. The presence of seeps from this shale indicates some component of ground water movement. The potential impact of this groundwater is discussed later in relationship to the proposed refuse disposal site for the life-of-mine plan. The major source of ground water along the Colorado River is provided by the alluvial deposits fringing the river which have relatively good water quality. Surface water tributaries and their alluvial bodies along the Colorado River also provide significant quantities of water for irrigation, stock, municipal and domestic purposes. Most local wells completed in the alluvial aquifers are less than 100 feet deep in the area of the mine. The alluvium in the are a. is recharged from contact with surface water of the Colorado River and its tributaries, and from upland sheet flow and snow melt. The alluvial bodies adjacent to the Colorado River will release water back to the surface water system during periods of low flow. Therefore, any impacts to the alluvial ground water also have potential to impact the quality or quantity of water within the Colorado River. The present permit term of the Coal Ridge #1 Mine will involve an operations plan that calls for minor disturbance both on the surface and underground, compared to the life-of-mine plan. The proposed surface disturbance for this permit term is 37.5 acres, compared to 256 acres for life-of-mine. The underground disturbance is proposed for 110 acres in this permit term, and 5900 acres for the life-of-mine plan. Obviously, the potential impacts of the life-of-mine plan are greater than under this permit term. This Probable Hydrologic Consequences section will focus upon those impacts of the life-of-mine, except where some variance might exist in this permit term. These life-of-mine impacts are projected to be worst case, and should not be realized during this permit term. The Coal Ridge No. 1 Mine is designed as a hydraulic mining process within the Wheeler coal seam. The hydraulic mining process is a relatively new development within the coal industry, which uses high pressure water to fracture and rubblize the coal. Entries within the coal seam are designed to move upslope so that gravity allows the slurry of coal and water to flow from the mining section to the portal. The entire mine is designed as a closed water system enabling reuse of almost all the water within the hydraulic system. The total acreage to be mined during the life-of-mine is 5,900 acres. The total surface disturbance proposed for the life-of-mine is 256 acres.