Laserfiche WebLink
I. Probable Hydrologic Consequences <br />A detailed analysis of the Probable Hydrologic Consequences has been prepared by <br />WFC and is contained in Section 2.05.6(3) of the permit application package. All <br />maps, figures and tables referenced in this section below are contained in the permit <br />document <br />1. Impact on groundwater rights. <br />Ground water rights within the immediate region (2 mile radius) around the New <br />Horizon Mine are presented in Appendix 2.04.7 -1 of the permit. In all, 29 ground <br />water rights have been identified in the vicinity of the New Horizon 1 and New <br />Horizon 2 mining areas. All monitoring wells installed by the permittee and <br />domestic wells within the surrounding area are shown on Map 2.04.7 -1 -A. Two <br />wells within the mine area will be affected, the Garvey well (Water Right 942) <br />and the Ernest well (Water Right #1). These wells, and the land in which they are <br />located, have been purchased by the permittee. <br />Of the 29 water rights within the surrounding area, 27 wells have intakes too <br />deep to be affected by the pit pumping induced drawdown in the overburden <br />aquifer. These wells are installed in the Burro Canyon Formation, which is below <br />the Dakota coals that were mined. Significant shales separate the coals from the <br />strata of the wells. Two righted wells, W -009 and W04, have intakes close to the <br />elevation of the bottom of the mine pit. The wells are located approximately <br />2,300 feet east of New Horizon 2 and will not be affected by the New Horizon 91 <br />Mine Area. At the eastern boundary of New Horizon 2, mining will only extend <br />10 feet below the water table. Therefore, drawdown impacts to these wells are <br />expected to be small. The wells are righted for irrigation water use. This area has <br />been mined and reclaimed for over 6 years ago and there has not been any <br />problem identified with these wells. <br />2. Impact of spoil material on groundwater flow and recharge. <br />The mine pit will remain open only until the coal has been removed. Following <br />the short -term water level decline on the groundwater system as a result of <br />pumpage of groundwater inflow to the pit, a potential long -term impact to the <br />local groundwater flow is the period of time necessary for resaturation of the <br />spoil material and reestablishment of a flow gradient. Another potential impact <br />is increased recharge into the spoil from precipitation and irrigation, resulting in <br />spoil springs developing downgradient. Figure 2.05.6(3) -1 in the permit <br />application package shows a general cross - section downgradient through the <br />New Horizon 92 mine spoil. <br />Spoil material at the New Horizon 2 mine will be replaced into the mine pit areas <br />using 3 techniques: 1) cast blasting, end dumping of trucks from the spoil bench <br />31 <br />