1997-05-05_GENERAL DOCUMENTS - C1980007

• Permit No: C1980007
• IBM Index Class Name: General Documents
• Doc Date: 5/5/1997
• Doc Name: Proposed Decision & Findings of Compliance for PR7
• From: Sylvester Gulch Facilities Area
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

haul/access road to the Sylvester Gulch fan, the entire length of the
proposed Substation access road and portions of the proposed Electric
Borehole access road. In addition there will be two stream crossings, one
is proposed at the intersection of the Sylvester Gulch haul/access road with
the Substation access road and one is located along Sylvester Gulch
haul/access road at culvert CSLY-4 located near the westem portion of the
ventilation facilities. The Division approves this stream buffer zone
variance in accordance with Rule 4.05.18(I). This decision is based on a
finding that the original stream channel will not be disturbed, water quality
and quantity will not be adversely affected, and appropriate riparian
vegetation will be reestablished. These conditions will be met by the
effective use of slope stabilization methods including Best Management
Practices, appropriate use of sediment control structures during construction,
revegetation, and mechanically stabilized earth (MSE) walls.
K. Probable Hydrologic Consequences
Under Rule 2.07.6(2)(c), the Division is required to make an assessment of the
probable cumulative impacts of all anticipated coal mining in the general area,
on the hydrologic balance and to make a finding (as discussed in Section A of
this document) that the operations proposed in the permit application have been
designed to prevent material damage to the hydrologic balance outside of the
proposed permit area. This section of the findings document is divided into the
following subsections: Description of the Hydrologic Environment, Probable
Hydrologic Consequences of the West Elk Mine, and Summary and Findings. A
separate Cumulative Hydrologic Impact Study (CHIS) is available for review at
the Division of Minerals and Geology. The Cumulative Hydrologic Impact
Study (CHIS) filed at the DMG office assesses the projected cumulative
hydrologic impacts of all anticipated mining operations in the general area of the
West Elk Mine on the North Fork of the Gunnison River Valley.
1. Description of the Hydrologic Environment
a. Regional Geology
For information regarding regional geology, see Section A, Description
of the Environment, Geology in this Findings Document.
b. Ground Water
Seven categories of potential aquifers occur in the Somerset Coal
Field. These are: 1) the alluvial and terrace deposits associated with
the North Fork of the Gunnison River; 2) the localized, shallow
alluvium along creeks tributary to the North Fork: 3) the
discontinuous, lenticular and laminar sandstones of the Mesaverde
Formation; 4) the Rollins Sandstone; 5) the coal seam; 6) shallow
colluvial surficial deposits; and 7) fracture zones in bedrock.
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