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• C' The following resources will be impacted from actions associated with the proposed action: Minerals Coal Approximately 344 acres would be removed from the Prairie Dog Lease Tract. This would decrease the Prairie Dog Tract from 11,517 acres to 11,173 acres. Approximately 2.1 million tons of coal would be removed reducing the estimated coal reserves within the Prairie Dog Tract from 44 million tons down to 41.9 million tons. This would be equivalent to approximately 2 years of annual production from the existing mine. In addition to the coal removed from the bypass lease area, an additional .3 million tons of coal reserve in lease C-023703 would also be removed from the buffer area. Oil and Gas Oil and gas production could not be impacted by the development of the tract for coal. The granting of a lease for the production of coal deposits shall preclude neither the issuance of prospecting permits or mineral leases for prospecting, development, or production of deposits of other minerals in the same land with suitable stipulations for simultaneous operation (43 CFR Ch. 11, 3400.1). HydroloRy Due to the nature of subsidence over a longwall system, the disturbance to the hydrological flow in and below the drainages is expected to be minimal. Subsidence occurs in a wave action following the longwall face. The extent of horizontal reaction in front of the longwall face is dependent on the angle of draw. As the longwall passes, cracks will open as the ground is placed in tension and then close as the stress wave proceeds beyond any given location. It is generally believed that any cracks that develop in the crust will be discon inuous. -- - It is not considered possible for water to flow from the surface and enter the mine area. There are 600-1,200 feet of overburden above the coal seam in the Red Wash area. When the coal is extracted the roof caves ~i immediately behind the longwall. The sw,g_ of the shales and sandstones ~, l soon fills the open cavity. There wil~'~"6~yno active collapse and caving ~J / I more than 30-40 feet ~QVe~he tov of the seam.- Following--t-heini~£ial // violent caving of the immediate roof, the overlying strata will deflect slowly with only minimal fracturing. Tension cracks will form in the crust and in the secondary layer in the creek bottom. However, the thick layer of fine silt present in the drainage systems in predicted to hide and quickly seal off any openings. ~ The effect of subsidence on the groundwater under the Red Wash is ~}-~ ~ unpredictable and purely speculative. tkz host pro6obCe e-~~~~T` o~ ~'K.n9 ~"~ af,~~'co.fNn arm ~~,,.[.L (e fo`ucuse~ a ~S~f'ea~.-. QLeu~t~~n/9vq~;~wf rnr-~er~t~h;Q~~+c~ se~r-v,Mewts o~ 2 W1as~11,'sct~wLfe,,1~~1/ oss:6 c6L~ ih G/~,rQ /;JNS ~ (o / nQ ~ a1~~.fLy av~e]r ttie (.ow~.~.~GC paHeCs~~ 13 [y ~ ~~pN-o~ PaI/ert~~~~~~o~ ~tli41N, i.2_ ~no~:,~ aT liLa r :n sub -G-~~~L?~~wsSio~'J,