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Finally, monitoring wells GW -N56 through GW -N58 are located south of the southwest end of <br />Cross 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 proposed mining area. <br />Relatively deep incision of the strata to be mined by Coal Canyon, Tuttle Draw and their <br />tributaries results in a somewhat small and isolated hydrologic system. This system is completely <br />isolated from the New Horizon Mine effects on both surface and ground water because of the <br />stream incision of Tuttle Draw. The projected outcrop of the LDx Seam is shown on Map 2.04.7- <br />1. The relative shallow strata of the affected ground water system and the relatively small area of <br />the surface drainage system are totally dominated by the effects of seasonal irrigation. Irrigation <br />was brought to Nucla in 1904. Map 2.04.7 -1 shows the locations of the "2 "d Park Lateral" the <br />primary artery of the irrigation system in the permit area. Disturbance within the permit will <br />primarily affect the topography, the overburden unit and the coal unit. The underburden will be <br />day - lighted by the pit floor but otherwise left in place. The 2"d Park irrigation water will be <br />diverted through a HDPE pipeline during and after mining. Irrigation within the permit boundary <br />will be suspended during mining. Percolation of water from the 2 "d Park Lateral and the flood <br />irrigation during mining into the underlying strata will be eliminated. The effects of reducing the <br />recharge into both the ground water and surface water systems are discussed in the appropriate <br />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from these wells provide historical reference and this information is contained in WFC's New 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. <br />Review of the hydrographs indicates that there is separation of the three zones (underburden, <br />coal, and overburden). Further, most of the monitoring wells show a gradual decline in water <br />level from October '08 through March of 2009 at which point they rapidly recover again. This <br />demonstrates the effect that the seasonal surface irrigation has on the ground water zones. The <br />water levels decline in the fall and winter after the irrigation water is shut off in the "2nd Park <br />Lateral" and rapidly recover in the spring when the irrigation flow resumes. The hydrograph for <br />GW -N9 (contained in the New Horizon 1 Permit and in the Appendix 2.04.7 -1 of this Section) <br />demonstrates this annual cycle from September 1979 through December of 1987. <br />After permit approval and prior to new disturbance, three (3) new ground water monitoring wells <br />were installed in the southwestern portion of the NHN permit area. The locations of these 3 new <br />Section 2.04.7 Page 2 October 2013 (TR -05) <br />E: \New Horizon \DRMS \NHN Permit \04 Technical Revisions TR \TR -05 \Documents from Jason \2.04.7 Hydrology Description_TR- 05.docx <br />