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extend under the Round Bottom alluvial valley floor. The 2 West workings of this mine <br />did, however, undermine approximately 90 acres containing surface and ground waters <br />tributary to the Round Bottom alluvial valley floor. The 2 West workings undermined <br />small ephemeral streams directly tributary to the Yampa River /Round Bottom alluvial <br />valley floor. The 2 West workings also undermined the Twentymile and Middle <br />Sandstone aquifers along the upper edge of the Round Bottom Synclinal Basin (a <br />regional ground water basin) and along the axis of the Williams Fork Anticline. <br />The 2 West workings have been abandoned for more than ten years. Only minor areas <br />had pillars pulled. Other mining was development by room and pillaring only. The <br />impacts to the quantity of water supplied to the Round Bottom AVF were previously (in <br />the 1984 Findings Document) predicted to be negligible upon evaluating the proposed <br />mine plan. Due to the reduced areas of mining, impacts are considered to be negligible <br />for both quality and quantity of water supplied to the Big Bottom AVE <br />The No. 5 Mine will not disrupt the essential hydrologic functions (e.g., the capacity for <br />flood irrigation) of the Round Bottom alluvial valley floor. The mine will neither <br />undermine the land surface of the alluvial valley floor nor undermine the irrigation <br />systems supplying the alluvial valley floor. Therefore, there will be no subsidence <br />impacts to areas of the Round Bottom alluvial valley floor as a result of mining in the 2 <br />West area of the No. 5 Mine. <br />The Division finds that Williams Fork Mines will not impact the essential hydrologic <br />functions of the Yampa River /Round Bottom alluvial valley floor, and will not impact <br />the quantity and quality of water supplied to this alluvial valley floor so as to reduce the <br />productivity of the alluvial valley floor. <br />A. The Division has determined that three alluvial valley floors exist within the <br />affected or adjacent area. Therefore, the following findings are in order for the <br />alluvial valley floors known as Williams Fork alluvial valley floor, Yampa <br />River /Big Bottom alluvial valley floor, and Yampa River/Round Bottom alluvial <br />valley floor. Map 25 of the permit depicts the locations of these resources. The <br />Division finds that activities proposed by the applicant will not interrupt, <br />discontinue, or preclude farming on the alluvial valley floors that are irrigated or <br />naturally subirrigated (4.24.3(1)). <br />The proposed activities will not materially damage the quantity or quality of water <br />in the surface or ground water system described above (424.3(3) and <br />2.06.8(5)(a)(ii)). <br />The proposed activities will comply with the requirements of the Act and the <br />Regulations with respect to alluvial valley floors (2.06.8(5)(a)(iii)). <br />The operation proposed by the applicant produced coal in commercial quantities <br />and was located within or adjacent to an alluvial valley floor prior to August 3, <br />1977 (424.3(4)(a) and 2.06.8(5)(b)(i)(A)). <br />Williams Fork Mines 40 Permit Renewal 06 <br />C- 1981 -044 December 8, 2014 <br />