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• available at this time and, therefore, it can be assumed that during spring the saturation of colluvium can be much higher due • to snowmelt. The "D" coal seam is saturated where the subcrop is located under the saturated portion of colluvium. Therefore, the initial near surface driving of entries will encounter dry conditions. Only in deeper portions, approximately 300 feet from the surface, will the coal seam become saturated. The permeability testing performed in the "D" coal seam indicated low values of hydraulic conductivity. Inflow of ground water into an entry at a distance of 300 to 600 feet from the surface was calculated as 0.26 gpm. This quantity of seepage would not cause any visible flow and would probably be consumed by evaporation. In deeper sections of the tunnels where the coal is under confined conditions, the seepage could increase to approximately 0.7 gpm per 100 feet of tunnel. This amount of seepage would probably not require discharge of water from the mine. Only if the entry driving encountered a fault or highly fractured Zone connected with colluvial sediments would the quantity of seepage increase. The potential for increased seepage into the entries driven underneath East Roatcap Creek was addressed in more detail in a previous report entitled "Water Inflow into the Orchard Valley Coal Mine, Paonia, • Colorado" (Hydro-Geo Consultants, May, 1985). The hydrogeologic study of the proposed portal bench area indicates that the construction will have an insignificant impact on the local ground water regime. The saturated portion of the colluvium will not be excavated and the seepage into the mine through the coal strata would have a small impact on water levels in colluvium due to the low permeability of both coal and colluvium. The impact on ground water quality in the colluvial strata would be limited by the fact that the excavated material will be composed predominantly of colluvium. Oniy a small quantity of weathered bedrock strata will be in the fill material and, therefore, the potential for exposure of soluble toxic materials to runoff and infiltration would be limited. The proposed surface drainage of the disturbed area and the compaction of the fill materials would also limit the amount of water percolating through the fill materials. There are no ground water supply wells within the East Roatcap Creek drainage and all identified springs are located upstream of the proposed construction. Therefore, there is no potential for impact on ground water rights within the project area. • 16