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Tuttle Draw. The surface water divide between Tuttle Draw and Coal Canyon is located in the <br />southernmost part of the mining area. Relatively deep incision of the strata to be mined by Coal <br />Canyon, Tuttle Draw and their tributaries results in a somewhat small and isolated hydrologic <br />system. This system is completely isolated from the New Horizon Mine effects on both surface <br />and ground water because of the stream incision of Tuttle Draw. The projected outcrop of the <br />LDx Seam is shown on Map 2.04.6-1. The relative shallow strata of the affected ground water <br />system and the relatively small area of the surface drainage system are totally dominated by the <br />effects of seasonal irrigation. Irrigation was brought to Nucla in 1904. Map 2.04.7-1 shows the <br />locations of the "2nd Park Lateral" the primary artery of the irrigation system in the permit area. <br />Disturbance within the permit will primarily affect the topography, the overburden unit and the <br />coal unit. The underburden will be day -lighted by the pit floor but otherwise left in place. The 2nd <br />Park irrigation water has been diverted through a HDPE pipeline during and after mining. <br />Irrigation within the permit boundary will not occur during mining, but will be reinstated to <br />support post -mine reclamation areas that require irrigation. Percolation of water from the 2nd <br />Park Lateral and the flood irrigation during mining into the underlying strata will be eliminated. <br />The effects of reducing the recharge into both the ground water and surface water systems are <br />discussed in the following sections. <br />Baseline Ground Water Levels WFC and Peabody maintained and operated a ground water <br />monitoring network in the NHN permit area consisting of 15 monitor wells (see Map 2.04.7-1). <br />Each monitor well was measured for static water level on a monthly basis. While monitoring of <br />some of these wells has been suspended and others have been plugged and abandoned, the data <br />from these wells provide historical reference and this information is contained in WFC's New <br />Horizon 1 and New Horizon 2 permit documents. None of these older wells are currently being <br />monitored. Monitoring wells GW -N47 through GW -N55 were added in the NHN permit area in <br />October 2008 (see Map 2.04.7-1). Typical completion diagrams one each for the overburden, <br />coal zone and underburden well completion monitoring zones are provided in Figure 1 of <br />Appendix 2.04.7-1. Water level and water quality monitoring began immediately upon <br />completion of these wells. Water levels of these wells are measured on a monthly basis and <br />water quality samples are measured quarterly. The tabulated water level data and resulting <br />hydrographs are contained in Appendix 2.04.7-1. Review of the hydrographs indicates that there <br />is separation of the three zones (underburden, coal, and overburden). Further, most of the <br />monitoring wells show a gradual decline in water level from October '08 through March of 2009 <br />at which point they rapidly recover again. This demonstrates the effect that the seasonal surface <br />irrigation has on the ground water zones. The water levels decline in the fall and winter after the <br />irrigation water is shut off in the "2nd Park Lateral" and rapidly recover in the spring when the <br />irrigation flow resumes. The hydrograph for GW -N9 (contained in the New Horizon 1 Permit <br />and in the Appendix 2.04.7-1 of this Section) demonstrates this annual cycle from September <br />1979 through December of 1987. <br />Section 2.04.7 Page 2 April 2016 (PR -01) <br />