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~J ~ UI~il -za- The predicted mine inflow for the fifth year (1988) to the Eagle No.S Mine is 1460 gallons per minute (gpm) and the predicted inflow to the Eagle No. 9 Mine is 960 gpm, (Table II-20d). These predictions are made with the assumption that mine inflows from faults and subsidence will not increase from present levels. (Also, calculated seepage inflow rates from Table III-20, page III-72a were doubled to Come up with the maximum projected inflows.) These projections may be low, given the significance of faults to mine inflows currently observed in the two Eagle Mines in mine areas located below stream/alluvial systems. Also, subsidence fracturing could significantly increase inflow rates beneath stream/alluvial systems. Given the unpredictability of the occurrence of faults subcropping beneath the stream/alluvial systems; and given the present state of the art of subsidence projections; the companies projections are reasonable. The actual impacts of mining (empiric data) on the quantity of surface and ground waters will be obtained through the inflow monitoring required by the Division and through mine inspections conducted by the Division staff. The total inflow rate per affected acre is greater in the Eagle No. 9 Mine than in the Eagle No. 5 Mine. This may be due to the greater piezometric head and hydrostatic pressures in strata affected by the Eagle No. 9 Mine. The Eagle No. 9 Mine is a relatively young mine in comparison to the Eagle No. 5 Mine. The drawdowns caused by the mine workings in affected aquifers would not be as extensive. The pietometric head difference and ground water gradient would be greater around the Eagle No. 9 Mine. This would increase the ground water flow rates towards the mine workings. The Eagle No. 9 Mine is also located near the axis of the Big Bottom Synclinal Basin where there are higher hydrostatic heads in water bearing strata (aquifers). This would also increase the quantity and the rate of ground water flow towards the mine workings. All inflows to the Eagle No. 9 Mine are from areas of partial extraction. No areas have been pillared, whereas, in the Eagle No. 5 Mine, areas have been pillared. Therefore, subsidence is presently not considered a source of mine inflows in the Eagle No. 9 Mine and was not used in predicting mine inflows. The projections of subsidence due to the development mains and the extractlon of room and pillar panels upon advance for the Eagle No. 9 Mine have been made using extrapolated data. Empiric data on subsidence will be obtained through stipulated subsidence monitoring in sections VII and XX of this permit document. If subsidence were to occur, there would be an increased communication between overlying rock aquifers and the Yampa River/Big Bottom stream/alluvial system and inflows would be expected to increase. Empire Energy Corporation has shown that the mine inflows at the Eagle No. and No. 9 Mines have lowered water level in overlying aquifers (Figures III-l7a through III-llc and III-17e through III-17g in the permit application). The company has also shown that the mines have dewatered the "f" and "P" coal seams and have lowered the ground water level in the coals (Appendices III-8b and III-ec of the permit application).