2009-05-22_GENERAL DOCUMENTS - C1981044

• Permit No: C1981044
• IBM Index Class Name: General Documents
• Doc Date: 5/22/2009
• Doc Name: Proposed Decision & Findings of Compliance for RN5
• Permit Index Doc Type: Findings
• Email Name: JRS
• Media Type: D
• Archive: No

be minor. The Round Bottom alluvial valley floor primarily supports flood irrigated
hayfields and pasturelands.
The Eagle No. 9 Mine workings are not in close proximity to nor do they impact areas
tributary to the Round Bottom AVF. Therefore, no impacts to the essential hydrologic
functions of the Round Bottom alluvial valley floor occurred. The Eagle No. 5 Mine
does not extend under the Round Bottom alluvial valley floor. The 2 West workings of
this mine did, however, undermine approximately 90 acres containing surface and
ground waters tributary to the Round Bottom alluvial valley floor. The 2 West
workings undermined small ephemeral streams directly tributary to the Yampa
River/Round Bottom alluvial valley floor. The 2 West workings also undermined the
Twentymile and Middle Sandstone aquifers along the upper edge of the Round Bottom
Synclinal Basin (a regional ground water basin) and along the axis of the Williams Fork
Anticline.
The 2 West workings have been abandoned for more than ten years. Only minor areas
had pillars pulled. Other mining was development by room and pillaring only. The
impacts to the quantity of water supplied to the Round Bottom AVF were previously (in
the 1984 Findings Document) predicted to be negligible upon evaluating the proposed
mine plan. Due to the reduced areas of mining, impacts are considered to be negligible
for both quality and quantity of water supplied to the Big Bottom AVF.
The Eagle No. 5 Mine will not disrupt the essential hydrologic functions (e.g., the
capacity for flood irrigation) of the Round Bottom alluvial valley floor. The mine will
neither undermine the land surface of the alluvial valley floor nor undermine the
irrigation systems supplying the alluvial valley floor. Therefore, there will be no
subsidence impacts to areas of the Round Bottom alluvial valley floor as a result of
mining in the 2 West area of the Eagle No. 5 Mine.
The Division finds that BTU EC will not impact the essential hydrologic functions of
the Yampa River/Round Bottom alluvial valley floor, and will not impact the quantity
and quality of water supplied to this alluvial valley floor so as to reduce the productivity
of the alluvial valley floor.
A. The Division has determined that three alluvial valley floors exist within the
affected or adjacent area. Therefore, the following findings are in order for the
alluvial valley floors known as Williams Fork alluvial valley floor, Yampa
River/Big Bottom alluvial valley floor, and Yampa River/Round Bottom alluvial
valley floor. Map 25 of the permit depicts the locations of these resources. The
Division finds that activities proposed by the applicant will not interrupt,
discontinue, or preclude farming on the alluvial valley floors that are irrigated or
naturally subirrigated (4.24.3(1)).
The proposed activities will not materially damage the quantity or quality of water
in the surface or ground water system described above (4.24.3(3) and
2.06.8(5)(a)(ii)).
Eagle Mine Complex 39 Permit Renewal 05
C-1981-044 May 22, 2009