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Given the small size (13.6 acres) and nature of the disturbance, no significant <br />hydrological impacts are anticipated. There is minimal potential for the quality of <br />water supplied to the alluvial valley floor via the Deer Trail Ditch or the Fire <br />Mountain Canal to be affected. <br />The canals are located upslope from the disturbed area. Irrigation runoff and storm <br />runoff will be diverted around the disturbance and disturbed flows will be routed <br />through a sediment pond prior to discharge. The applicant has obtained water rights <br />to Deer Trail Ditch water totalling 300 acre -feet per year and anticipates a <br />maximum operational need of approximately 44 acre -feet per year. Forty-four acre - <br />feet is approximately .01% of the mean annual flow of the North Fork. <br />The applicant's discussion of probable hydrologic consequences has identified no <br />anticipated changes in surface water quality. All runoff from disturbed surface <br />areas drains through an approved sediment control system. No material damage to <br />the quality of surface waters supplied to the alluvial valley floor is anticipated, due <br />to sediment control at the site and the fact that the ditch, which supplies the AVF is <br />located upslope of the disturbance. <br />There is a slight potential for water quality degradation to occur in the alluvial <br />aquifer immediately down gradient of the loadout pad as a result of percolation of <br />degraded water through the colluvium. This potential is considered insignificant for <br />the following reasons. First, the small amount of degraded percolation water that <br />would infiltrate would be rapidly diluted by existing water in the system. The <br />amount of percolation water would be minimized by the small size of the <br />contributing drainage area (less than 15 acres) and the fact that the compacted <br />surface of the pad will favor runoff over infiltration. Once operations are <br />completed, the coal stockpile and sediment pond will be reclaimed and the potential <br />for water quality degradation will cease. <br />Pursuant to Rules 4.24.2(1) and (2), the Division finds that surface coal mining and <br />reclamation operations would be conducted to preserve, throughout the mining and <br />reclamation process, the essential hydrologic functions of alluvial valley floors not <br />within the affected area and would be conducted to reestablish the essential <br />hydrologic functions of the alluvial valley floor within the affected area. <br />As stated previously, operations are not expected to materially damage the quantity <br />and quality of surface and ground water that supply the alluvial valley floor <br />downstream from the permit area. Pond discharge sampling, as specified in Section <br />V of this document, will be implemented to document the assumptions of this <br />finding. Operations, as presented in the application, will not interfere with or <br />preclude irrigation of those portions of the AVF not within the affected area. <br />Appropriate culverts and ditches have been required, where necessary. <br />XVIIL Operations on Prime Farmland <br />A. Pursuant to Rule 2.07.6(2)(k), the Division has made a negative determination for the <br />presence of prime farmland within the proposed permit area. The decision was based on <br />mapping by the U.S. Soil Conservation Service, which demonstrates that no prime <br />farmland mapping units are found within the permit area. <br />22 <br />