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Maps 2.04.5-1 (General Geology and Hydrology Map), 2.04.6-4 and 2.04.6-5 (Geologic Cross <br />Sections A —A' and B -B') graphically illustrate the site specific geology at the NHN area. New <br />ground water monitoring wells GW -N47 through GW -N49 are located on the northwest end of <br />Cross Section A -A'. Monitoring wells GW -N50 through GW -N52 and GW -N53 through GW - <br />N55 are located on the northeast and southwest ends respectively of Cross Section B -B'. Finally, <br />monitoring wells GW -N56 through GW -N58 are located south of the southwest end of Cross <br />Section B -B'. <br />The NHN Mine permit area is shown on Maps 2.04.5-1 and 2.04.7-1. These maps also show the <br />topography of the NHN area. The permit area is drained to the west and north by tributaries of <br />Coal Canyon and to the south by tributaries of Tuttle Draw. The surface water divide between <br />Tuttle Draw and Coal Canyon is located in the southernmost part of the mining area. Relatively <br />deep incision of the strata to be mined by Coal Canyon, Tuttle Draw and their tributaries results in <br />a somewhat small and isolated hydrologic system. This system is completely isolated from the <br />New Horizon Mine effects on both surface and ground water because of the stream incision of <br />Tuttle Draw. The projected outcrop of the LDx Seam is shown on Map 2.04.7-1. The relative <br />shallow strata of the affected ground water system and the relatively small area of the surface <br />drainage system are totally dominated by the effects of seasonal irrigation. Irrigation was brought <br />to Nucla in 1904. Map 2.04.7-1 shows the locations of the "2nd Park Lateral" the primary artery of <br />the irrigation system in the permit area. Disturbance within the permit will primarily affect the <br />topography, the overburden unit and the coal unit. The underburden will be day -lighted by the pit <br />floor but otherwise left in place. The 2 n Park irrigation water will be diverted through a HDPE <br />pipeline during and after mining. Irrigation within the permit boundary will be suspended during <br />mining. Percolation of water from the 2nd Park Lateral and the flood irrigation during mining into <br />the underlying strata will be eliminated. The effects of reducing the recharge into both the ground <br />water and surface water systems are discussed in the appropriate places in the following. <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. Nine new monitor wells (GW -N47 through GW -N55) were added in the NHN permit <br />area in October 2008 (see Map 2.04.7-1) of this application. Typical completion diagrams one <br />each for the overburden, coal zone and underburden well completion monitoring zones are <br />provided in Figure 1 of Appendix 2.04.7-1. Water level and water quality monitoring began <br />immediately upon completion of these 9 wells on October 10, 2008. Water levels of these new <br />wells are measured on a monthly basis and water quality samples are measured quarterly. The <br />tabulated water level data and resulting hydrographs are contained in Appendix 2.04.7-1. Review <br />Section 2.04.7 Page 2 Sept. 2015 (TR -11) <br />