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significance since all disturbed areas will be protected by a system of sediment ponds. Contour <br />ripping, mulching and revegetation have been demonstrated to minimize soil erosion and will be <br />used to mitigate the increased runoff potential until the topsoil structure is developed. Irrigation <br />will help this to occur rapidly. <br />8) Effects Of Sediment Ponds On Channel Characteristics and Downstream Users Potential <br />impacts of sediment ponds on downstream users will involve possible reductions in flow due to <br />impounded water. The water augmentation plan (included in the Appendix 2.05.6(3) -lc to this <br />Section) discusses the available water which will be used should impacts be identified. NHN <br />currently has rights to a sufficient quantity of water to supply all users associated with the mining <br />activities, plus an additional quantity of water that can be used to mitigate any impact to <br />downstream users. <br />9) Effects Of Sediment Pond Discharge On Surface Water Quality The effects of sediment <br />ponds on surface water quality will be negligible because each sediment structure has been <br />designed to minimize impacts to the hydrologic balance. The ponds involve such minor areas of <br />disturbance that chemical and sediment changes in the flows will be immeasurable. <br />10) Effects of Runoff from Reclaimed Areas on the Quality Of Streamflow Due to the <br />relatively small area of disturbance in the NHN Mine area, any reductions in runoff will have <br />only a minimal impact on streamflow quantity, as flow in Tuttle Draw is dominated by irrigation <br />return flow. Decreased sediment loads predicated by SEDCAD (see New Horizon #2 Area <br />permit) indicate that reclamation efforts conducted in the mining area will ensure that additional <br />contributions of suspended sediment in runoff from reclaimed areas will not occur. Irrigation of <br />reclaimed area will utilize sprinklers instead of flood irrigation that should further reduce erosion <br />and sediment load. Based on past operating history at both Nucla Mine and the adjacent New <br />Horizon Mine, no significant trend toward higher concentrations of the selected parameters has <br />been detected. In addition, the pond discharge will be monitored in accordance with NPDES <br />discharge limitations and any potential impact will be identified. Therefore, runoff from the <br />reclaimed area should have no significant impact over time on the quality of receiving stream <br />waters. As a result, post mining land uses which currently occur in the area should not be <br />affected due to the projected mining plan. <br />Summary The discussion presented herein of the probable hydrologic consequences of the NHN <br />mine plan identifies the potential effects of mining. Table 2.05.6(3)-2a located in Appendix <br />2.05.6(3)-2 of this permit application summarizes the discussion by listing the probable <br />hydrologic consequences and the results of the analysis of each. As can be seen, all of the <br />probable impacts have been determined to be of a short term nature, of minimal significance, or a <br />plan has been presented to mitigate those determined to have some significance. As a result, <br />mining and post mining effects to the current land uses should be negligible. <br />Section 2.05.6(3) Page 27 March 2018 (TR -16) <br />