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in the water augmentation plan, WFC has a 114 acre foot consumptive use right on the Highline <br />Canal which would be used to mitigate the potential 26 acre foot impact on surface water right <br />users from pit inflow drawdown. <br />3)Impactongroundwaterrights. Ground water rights within the immediate region (2 mile radius) <br />around the New Horizon Mine are presented in Appendix 2.04.7 -1. In all, 29 ground water rights <br />have been identified in the vicinity of the New Horizon 1 and New Horizon 2 mining areas. All <br />monitoring wells installed by the permittee and domestic wells within the surrounding area are <br />shown on Map 2.04.7 -1 -A. Two wells are within the mine area will be affected, the Garvey well <br />(Water Right #42) and the Ernest well (Water Right #1). These wells, as well as the land in which <br />they are located, have been bought by the permittee. <br />Of the 29 water rights within the surrounding area, 27 wells have intakes too deep to be affected <br />by the pit pumping induced drawdowns in the overburden aquifer. These wells are installed in the <br />Burro Canyon Formation, which is belowthe Dakota coals to be mined. Significant shales separate <br />the coals from the strata of the wells. Two righted wells W -009 and W041 have intakes close to <br />the elevation of the bottom of the mine pit. The wells are located approximately 2,300 feet east of <br />New Horizon 2. At the eastern boundary of New Horizon 2, mining will only extend 10 feet below <br />the water table. Therefore, drawdown impacts to these wells are expected to be small. The wells <br />are righted for irrigation water use. This area has been mined and reclaimed over 6 years ago and <br />there has not been any problem identified with these wells. Although some data on these wells is <br />available in Attachment 1 of this section, WFC will attempt to gather some additional information <br />from a few of the nearby water supply wells to the New Horizon #2 Mine. <br />4) Impact of spoil material on groundwater flow and recharge. The mine pit will remain open <br />only until the coal has been removed. Following the short -term water level decline on the <br />groundwater system as a result of pumpage of groundwater inflow to the pit, a potential long -term <br />impact to the local groundwater flow is the period of time necessary for resaturation of the spoil <br />material and reestablishment of a flow gradient. Another potential impact is increased recharge <br />into the spoil from precipitation and irrigation, resulting in spoil springs developing downgradient. <br />Figure 2.05.6(3) -1 shows a general cross - section downgradient through the New Horizon #2 mine <br />spoil. <br />Spoil material at the New Horizon 2 mine will be replaced into the mine pit areas using 3 <br />techniques: 1) cast blasting, end dumping of trucks from the spoil bench and dozing. These <br />Revised August 2010 (PR06) 2.05.6(3) -21 <br />