GENERAL41258

• Permit No: C1981034
• IBM Index Class Name: General Documents
• Doc Date: 6/14/1993
• Doc Name: PROPOSED DECISION & FINDINGS OF COMPLIANCE FOR RN2
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

250 feet thick in places and composed of loose gravel and boulder material.
water quality is high and can be considered as acceptable for potable and
irrigation uses.
The bedrock aquifers are much lower in potential yield. The coal beds are
relatively thin, less than 10 feet, and rely on secondary fracture porosity to
transmit water. it is estimated that these aquifers have a permeability on the
order of 100 times less than the overlying alluvial glacial outwash materials.
Water quality analyses from the vicinity of the Red Canyon Mine indicate that the
water is primarily of a sodium bicarbonate type having dissolved solids ranging
from 258 mg/1 in the F seam to 1354 mg/1 in the E seam.
There are a number of water wells that exist in the area. Depths are shallow and
yields low enough so as to not affect the underlying bedrock aquifers. Mining
and dewatering of the coal seams should not significantly interfere with
utilization of this water in the immediate area. The largest yields from these
wells are 15 to 20 gallons per minute (gpm) and are designated as domestic use
only. It appears that the majority of these wells are producing water from the
glacial alluvial cover and not from bedrock aquifers.
The sandstone bedrock aquifers are usually thin, less than 20 feet, very fine
grained, highly cemented, and generally unfractured, except where regional joint
patterns exist. These sandstones were deposited in lenticular, delta-like bar
and lagoon sands and are not laterally extensive. The hydraulic potential of
these sandstones is limited and does not permit large capacity wells to be
predicted or developed in these units. The Rollins Sandstone is the exception
and, although it is usually 100 or more feet thick and is very extensive
laterally, yields from a well in the Rollins Sandstone would not be expected to
yield more than 25 to 50 gpm. The Rollins Sandstone ie approximately 300-
350 feet stratigraphically below the proposed D seam workings.
Surface water information can be found in the permit in Section 2.04.5(1). In
addition, Volume 8 of the permit addressed a number of concerns expressed by the
Division during the first permit review with regard to potential impacts of the
operation on the surface water regime. Volume 9 of the permit contains post-
mining drainage profiles and cross sections of the disturbed area.
A description of surface water occurrence and mining impacts on surface water
within the permit and adjacent areas can be found in the "Probable Hydrologic
Consequences of Mining" section of this document and the "Cumulative Hydrologic
Impact Study" document for this mine area.
Surface drainage systems within or adjacent to the permit area are Ward Creek,
Williams Creek, Cottonwood Creek, Kiser Creek, Rowell Draw, and agricultural
irrigation systems. Both Ward and Williams Creek are calcium bicarbonate water
with low salinities (TDS ranging from 100-300 mg/1).
Geology-Rule 2.04.5 and 2.04.6
The geology sections in the permit application can be found in Section 2.04.5.
For a description of the geology of the area, refer to the "Probable Hydrologic
Consequences of Mining" section of this document.
Climatological Information-Rule 2.04.8
The climatological information in the permit application can be found in
Section 2.04.8.
The Red Canyon Mine lies on the southern slope of Grand Mesa in a small box
canyon about 5 miles northwest from Cedaredge, Colorado. The closest climatic
data station is in Cedaredge at an elevation on 6200 feet. The climate is
considered semi-arid with an annual precipitation of 12-14 inches.