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Map 35A and Map 52 indicate the locations of AVF well sites and the location of alluvial valley <br />floors. The Coy well drilled into the alluvium of Flume drainage functions as a point of <br />compliance well. Four wells are drilled into the Pyeatt alluvium, well J1 is located in the Johnson <br />drainage alluvium and one of the three GLEV wells in the Deacon drainage reached the alluvium at <br />the very north east corner of the permit. This GLEV well is located downgradient of any mining to <br />the east that may occur in the future. These wells constitute an environmental monitoring system <br />during surface coal mining and reclamation operations continuing until release of all bonds in <br />accordance with Rule 3 (4.24.4). <br />Four gulches (No Name, Johnson, Pyeatt, and Flume) are determined not to be alluvial valley <br />floors based on their absence of water availability sufficient for flood -irrigation or sub -irrigation <br />agricultural activities. <br />Potential impacts to the Yampa River AVF resulting from the proposed mining operation are <br />negligible. Generally, the Yampa River AVF receives very little of its water supply (surface and <br />ground water) from the proposed mine area. The majority of the flow in the river and subsequent <br />recharge to the alluvial aquifer derive from the headwaters portions of the drainage, far upstream <br />from Trapper. The applicant states that the contribution of surface water from the Trapper mine is <br />insignificant as per page 2-533 of the permit application. <br />This is substantiated by seepage, runoff, and potentiometric studies in Appendix H of the permit <br />application. Based on the information presented by the applicant, the Division finds that proposed <br />surface coal mining operations will not interrupt, discontinue, or preclude farming on the Yampa <br />River AVF, nor materially damage surface or ground water quantity or quality in systems <br />supplying the Yampa River AVF (4.24.3(l)),(4.24.3(3), and 2.06.8(5)(a)(ii)). <br />The potential for impacts from mining to the Williams Fork AVF is also negligible. The <br />Williams Fork River is located south of the proposed mining area. Almost exclusively, spring <br />snowmelt comprises the only surface discharge from sediment ponds in the drainages flowing <br />towards the Williams Fork River. It is likely that much of the discharge from these ponds infiltrate <br />into the permeable Twentymile Sandstone outcrop prior to reaching the Williams Fork River. <br />Therefore, the Division finds that the proposed surface coal mining operations will not interrupt, <br />discontinue, or preclude farming on the Williams Fork AVF, and will not materially damage the <br />quantity or quality of water in surface or ground water systems that supply the Williams Fork <br />AVF (4.24.3(l)),(4.24.3(3), and 2.06.8(5)(a)(ii)). <br />The Division finds that: <br />1. Proposed mining activities comply with the requirements of the Act and the <br />Regulations with respect to alluvial valley floors, (2.06.8(5)(a)(iii)). <br />2. The surface coal mining and reclamation operations will be conducted to <br />preserve the essential hydrologic functions of alluvial valley floors outside the <br />permit area and to reestablish the essential hydrologic functions of alluvial valley <br />floors within the affected area throughout the mining and reclamation process (4. <br />24.2). <br />22 <br />