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undermined small ephemeral streams directly tributary to the Yampa River/Round <br />Bottom alluvial valley floor. The 2 West workings also undermined the - <br />Twentymile and Middle Sandstone aquifers along the upper edge of the Round <br />Bottom Synclinal Basin (a regional ground water basin) and along the axis of <br />the Williams Fork Anticline. <br />The 2W workings have been abandoned for approximately 2 years at this <br />writing. Only minor areas had pillars pulled. Other mining was development <br />by room and pillaring only. The impacts to the quantity of water supplied to <br />the Round Bottom AVF were previously (in the 1984 Findings Document) predicted <br />to be negligible upon evaluating the proposed mine plan. Due to the reduced <br />areas of mining, impacts are considered to be negligible for both quality and <br />quantity of water supplied to the Biq Bottom AVF. <br />The Eagle No. 5 Mine will not disrupt the essential hydrologic functions <br />(e. g., the capacity for flood irrigation) of the Round Bottom alluvial valley <br />floor. The mine will neither undermine the land surface of the alluvial <br />valley floor nor undermine the irrigation systems supplying the alluvial <br />valley floor. Therefore, there will be no subsidence impacts to areas of the <br />Round Bottom alluvial valley floor as a re suit of mining in the 2 West area of <br />the Eagle Na. 5 Mine. <br />The Division finds that Empire Energy Corporation will not impact the <br />essential hydrologic functions of the Yampa River/Round Bottom alluvial valley <br />floor, and will not impact the quantity and quality of water supplied to this <br />alluvial valley floor so as to reduce the productivity of the alluvial valley <br />floor. <br />This section is in compliance for the Eagle Mines No. 5 and No. 6. <br />VIII. Cumulative Hvdrolovic Impact Study and Probable Hydrologic <br />Rule 2.07.6(2)(c) requires the Division to make an assessment of the probable <br />cumulative impacts of ail anticipated coal mining in the general area on the <br />hydrologic balance and to make a finding that the operations proposed in the <br />permit application have been designed to prevent damage to the hydralgoic <br />balance outside the proposed permit area. This section is divided into the <br />following sub-sections; A) Introduction and Background of the General Area; B) <br />Definition of anticipated Mining in the General Area; C) Description of the <br />Existing Environment; D) Probable Hydrologic Consequences; E) Hydrologic <br />Monitoring; F) Cumulative Hydrologic Impacts Study; and G) Summary and <br />Findings. <br />This Cumulative Hydrologic Impact Study (CHIS) assesses the projected <br />cumulative hydrolgic impacts of all anticipated coal mining operations in the <br />general area of the Eagle No. 5 and No. 6 Mines. Anticipated mining is <br />defined as the proposed life of mine areas for the existing mines and those <br />mines for which complete permit applications have been submitted to the <br />Division. <br />_19_ <br />