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HYDROLOGIC BALANCE - GROUND WATER A. Description of Existing Environment Geology The Deserado Mine Plan Area is located in the White River Basin, the eastern part of the larger Uinta Basin which extends from northwest Colorado west into eastern Utah. The rocks wihtin the mine plan area are the interbedded sandstone and silts tone strata of the Upper Williams Fork Formation: Mesa Yerde group. The Mesa Verde Group has been divided into two sections: the Lower Iles Formation and the Williams Fork Formation, which are separated by the Trout Creek Sandstone. The Williams Fork Formation is further divided into Upper and Lower Members. The Lower Williams Fork contains coal seams A through H, of which the D and B seams will be recovered by the proposed underground operation. Maps 4 and 121 in the application are plan view maps showing the geology of the area. Within the mine plan area dips of the strata have been determined by the Red Wash Syncline, an assymonetrical flexure on the northern limit of the Rangely Anticline, the axis of which is located beneath the Refuse Disposal site in the northern section of the permit area and also trends northwest/southeast. Dips vary from 7° northeast in the southern part of the permit area, to horizontal at the synclinal axis, to as much as 70° south-southwest north of the permit area on the north flank of the syncline. The coal and sandstone beds outcrop along this steep northern flank. Structure and local topograptry are the main factors which control ground water movement in the area. Western Fuels has divided the Williams Fork Formation into three hydrologic facies: the Lower Sandstone Facies, which lies beneath the "A" coal seam and is generally equivalent to the Trout Creek Sandstone and the upper portion of the Iles Formation; the Siltstone and Coal Facies, which consists of the inter- bedded coal, siltstone, and shale strata of the Lower Williams Fork; and the Upper Sandstone Facies of the Upper Williams Fork. The applicant did not de- fine exactly which units within the above noted formations are water bearing and instead studied each entire formation as a whole. Due to the complex 1