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Springs <br />There are no definable springs at the New Horizon 2 mining area. <br />Ground Water Suitability <br />Present Ground Water Use <br />Ground water rights within the immediate region (2 mile radius) around the New Horizon Mine are <br />presented in Peabody Attachment 16-1. In all, 29 groundwater rights have been identified in the vicinity of <br />the New Horizon 1 and New Horizon 2 mining areas. Of the 29 wells, 27 have intakes too deep to be <br />affected by the pit pumpage induced drawdowns in the overburden aquifer. Two righted wells W-009 and <br />W041 have intakes close to the elevation of the bottom of the mine pit. The wells are located approximately <br />2,300 feet east of New Horizon 2. At the eastern boundary of New Horizon 2, mining will only extend 10 <br />feet below the water table. Therefore, drawdown impacts to these wells are expected to be small. The <br />wells are righted for irrigation water use. <br />Potential Ground Water Use <br />This section will evaluate the use potential of the local, shallow ground water aquifers by comparing the <br />water quality against domestic drinking water standards, livestock drinking water standards and irrigation <br />use standards. The shallow aquifers will also be evaluated in terms of water yield potential. <br />In comparison to domestic drinking water standards, all aquifers at the New Horizon 2 mining area exceeded <br />at least two of the drinking water standards and some exceeded as many as seven of the standards (refer to <br />Peabody Tables 7-32A and 7-32B). The most frequent domestic drinking water standards exceeded were <br />iron, manganese, ammonia and sulfate. Well GW -N16, an underburden monitoring well in the New <br />Horizon 2 mining area had the best overall water quality and only exceeded the pH and ammonia standards. <br />The Dakota coal aquifers and the overburden aquifer in the New Horizon 2 mining area yielded ground water <br />that exceeded one or more of the livestock drinking water standards. The coal aquifer in the New Horizon 2 <br />mining area has poor quality with regard to agricultural water use. <br />A comparison of TDS values for the New Horizon wells indicates that 3 wells exceeded the 5,000 mg/1 limit, <br />12 wells yield water that could only be used for tolerant plants on permeable soils with careful management <br />practices, and 2 wells yielded water that might have adverse effects on crops and requires careful <br />management practices. Shallow ground water aquifers at New Horizon were unsuitable for irrigation use. <br />Plots of SAR's versus conductivity for each of the wells showed that the ground water fell into one of two <br />categories. It was either a high to very high salinity hazard and a low sodium hazard (12 wells) or a high to <br />very high salinity hazard and a very high sodium hazard (2 wells). <br />Wells yields and aquifer characteristics of the shallow aquifers at the New Horizon Mine were also <br />considered when evaluating potential water uses. Transmissivity values ranged from 77 to 1.1 ftZ/day and <br />pumping rates above 1.5 gpm could not be maintained for any significant period of time. Where shortterm, <br />pumping withdrawal tests (McWhorter's analyses) were performed specific capacities of only 0.1 to 0.6 <br />gpm/ft could only be maintained over short time periods. Aquifer yields were too low for irrigation <br />purposes and only poor to fair for domestic purposes. Assuming yields necessary for livestock water would <br />be similar to domestic needs, the aquifer yield potential for livestock use was also fair to poor. <br />Page 2.04.7-14 March 2017 (TR -77) <br />