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Eagle No. 5 Mine. Ground water flows in the Round Bottom Syncline in the vicinity of the proposed Sugarloaf Mine are to the east, toward the axis of the Round Bottom Syncline. Faults within the general area may provide a vehicle for ground water communication between overlying and underlying aquifers, between aquifers and underground mine workings or open pits, and between aquifers and the overlying surface stream/alluvial systems. The faulting produces increased fracturing within and between aquifers (secondary porosity). These more porous fault zones with their higher permeabilities cazt control both vertical and horizontal movement of ground water between and within aquifers. In areas where hydrostatic heads are higher in the underlying aquifers than the overlying surface elevation or the hydrostatic heads in overlying aquifers, the vertical movement of water through the fault system would be either upward and discharge to the surface/alluvial systems, or upward and recharge overlying aquifers. The Trout Creek Sandstone subcrope beneath the stream/alluvial systems of the Williams Fork and Yampa Rivers and outcrops along the valley walla of the rivers, and at the edges of the synclinal basins. The .Trout Creek Sandstone ie confined by the underlying shales of the Iles Shale and the overlying interbedded and lenticular shales, sandy shales, coals, and sandstones. The Bagle No. 5 Mine is separated from the Trout Creek Sandstone by 320 to 360 feet of interburden. Empire Energy Corporation drilled three water supply~welle in the Trout Creek Sandstone, two at the No. 5 Mine, and one at Okie Park. Well yields from thi~,s aquifer are highly variable and range from 10 gpm to 100 gpm. Based on an aquifer test conducted in the No. 5 Mine Well, the hydraulic conductivity in the Trout Creek Sandstone is about 0.71 gpd/ftZ, and the transmisaivity is about 0.01 gpd/ft. The Trout Creek is an important regional sandstone aquifer used primarily for industrial and domestic uses. The Middle Sandstone lies 61 to 267 feet above the F coed seam. It ie recharged along the valley walls of the Williams Fork az~d Yampa Rivers and along ridges in the general area. The Middle Sandstone ie recharged by and discharges to the stream/alluvial systems of the rivers. This sandstone aquifer is artesian downdip of its outcrops and subcrops. No water supply wells are completed in this aquifer in the general area. Empire Energy Corporation installed six monitoring wells in the Middle Sandstone; TR-4, TA-7A, 81-01, 83-.01, 83-02, and .83-03. These wells are monitored for ground water levels and water. quality.. The applicant's aquifer testa of this sandstone yielded low transmiesivity values (0.7 gpd/ft) and low storativity values (0.00045 and 0.0015, page III-46). The Twentymile Sandstone lies approximately 200 feet above the Middle Sandstone, 370 feet below the P coal seam, and 220 feet below the R coal seam, the lowest coal seam to be mined at the nearby Trapper Mine. The sandstone underlies much of the permit area of the Eagle Mines and forma broad outcrop areas near the central portions of the permit areas of the Eagle and Trapper Mines along the valley walls of the Williams Fork and Yampa Rivers. Pustping tests performed for the Trapper Mine by Utah International, Inc. on the Twentymile Sandstone yielded values for tranamissivity of 77 to 85 gpd/ft. Utah International, .Inc. postulated that these values are very low, given the yield of the 1}rentymile Sandstone near the axis of the Big Bottom Syncline. In the Big Bottom Basin, Utah International, Inc. obtained yield of 500 gpm and they postulated trans- missivity values of 5,000 gpd/ft and hydraulic conductivity values of 50 gpd/f t=. Both Trapper Mining Inc. and fimpire Energy Corporation have water wells completed in the Twentymile Sandstone; the Trapper Mine office facility well and the Eagle No. 9 Mine well. The Trapper Mine well (GD-1) produces 75 gpm. The Eagle No. 9 well produces 9.6 gpm. Other wells are completed in .this sandstone and used for domestic supplies in the general area. 17