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Greys one Uevelopmenl Consultants, Inc. June 10, 1986 Page 4. The Wadge overburden and Trout Creek Sandstone aquifers are projected to be affected by the proposed mining operation. The Wadge overburden has been calculated to discharge approximately 12 acre-feet per year to the surface in the area to be effected by mining operations. The dewatering and lowering of the potentiometric surface will probably result in most of this discharge being eliminated. Drawdown in the Trout Creek Sand- stone, as a result of mine inflow via fault zones, would also result in decreased flow of natural discharge in the north and northeast margins of the Twentymile Park Basin. A long term reduction of potential alluvial recharge in the order of 48 acre- feet per year is expected. Thus, drawdown in these aquifers may result in a maximum loss of 60 acre-feet per year to the alluvium of Fish and Foidel Creeks. • Average annual inflow to the mine is predicted to be 250 gpm or approximately 405 acre-feet per year. This inflow will provide the water to more than offset the predicated 60 acre- feet per year reduction in alluvial recharge to Fish and Foidel • Creeks. Deep Aquifer Pumpage The Foidel Creek Mine will utilize deep aquifer pumpage from a well completed in the Trout Creek Sandstone Aquifer. Based on previous use, 17 gpm or 27 acre-feet per year will be utilized for mine operations water. Postmining Inflow to Workings Following cessation of mining operations, the underground mine will be allowed to flood. Based on modeling calculations from the probable hydrologic consequence, it will take 350 years to flood the workings at the projected inflow rate of 220 acre- feet per year. As described above, this inflow will come from the Wadge overburden and Trout Creek Sandstone aquifers. This inflow is considered insignificant to the overall storage and recharge capacity of these aquifers within the Twentymile Park Basin. Revised 10/24/86