Laserfiche WebLink
4.4 Ground Water Movement <br />/) <br />Water movement in the saturated strata in [he Upper Williams Fork Forma- <br />tion and Twenty Mile Sandstone on [he mine site is primarily parallel to <br />the bedding, i.e. downdip, towards the axis of the Big Bottom syncline <br />(Woodward-Thorfinnson, 1975). Flow lines are approximately perpendicular <br />[o Che structural contours of the Trout Creek Sandstone shown in Figure <br />4-3. After reaching the axis of the Big Bo[[om, water flow bends <br />northwestward and changes to [he plunge of [he syncline. <br />The flow path is important [o define the feasibility of groundwater from <br />the mining area mixing with the alluvial aquifer of the Yampa River. <br />Studies summarized in Section 4.2.4 demonstrate the potentials for <br />1 groundwater movement both parallel and perpendicular to the bedding. <br />•~ This is feasible if the aquifers below [he Trapper Mine area are hydrau- <br />lically connectd to the alluvial aquifer of the Yampa River. The piezo- <br />meter studies referred to in Section 4.2.4 indicate such a continuity is <br />not present. The water levels are a[ different elevations in the i <br />piezometers installed in different strata. Moreover, [he groundwater <br />gradients in these strata are no[ parallel. These relationships between <br />strata demonstrate that cross bed Elow under the mine plan area if <br />present, would be through joints and very limited. This is also <br />confirmed by pump tests conducted by Colder (1976) which indicated that <br />[he uppermost aquifer in [he Williams. Fork Formation was separated from <br />[he next water bearing strata by confining layers. , <br />•~ <br />-36- <br />