GENERAL50201

• Permit No: C1991078
• IBM Index Class Name: General Documents
• Doc Date: 12/14/1992
• Doc Name: PROPOSED DECISION & FINDINGS OF COMPLIANCE FOR PR1
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

In accordance with Rule 4.05.13(4), an
report will be prepared and submitted
March 15th of each year. The report w
monitoring data, including laboratory
the previous year.
annual hydrologic
to the Division by
ill contain all
analytical reports for
Probable Hydrologic Consequences
Ground Water
The proposed permit area for the Hamilton Mine consists of 677
acres and is located approximately 2 miles southeast of the town of
Naturita in Montrose County. The proposed permit area overlies part
of the Nucla-Naturita Coal Field. The area is characterized
topographically by dissected mesas sloping to the north toward the
San Miguel River. The region is underlain by sedimentary rocks of
Jurassic and Cretaceous age which dip gently to the north. The
entire proposed permit area is underlain by the Lower Cretaceous
Dakota Sandstone, which consists of interbedded conglomeratic
sandstones, dark-gray carbonaceous shale, and numerous coal seams.
Five coal seams are present in the Dakota Sandstone in the permit
area, three of which are of mineable thickness.
Underlying the Dakota Sandstone is the Lower Cretaceous Burro
Canyon Formation, which is approximately 150 feet thick in the
area. It consists generally of two beds of conglomeratic sandstone,
each 10 to 40 feet thick, separated by a shale sequence. The lower
sandstone of the Burro Canyon Formation contains the only
significant ground water accumulations in the permit area. This
aquifer lies 90 to 100 feet stratigraphically below the lowest coal
seam to be mined. The applicant has monitored wells BW-1, BW-2, and
BW-3 to establish pre-mining water levels and quality. Yield from
these wells vary from zero to three gallons per minute. No other
ground water development has taken place in the vicinity of the
permit area.
Five springs or seeps have also been located in and around the
permit area at the contact of the Burro Canyon and the underlying
Morrison Formation. The discharge of these springs is generally so
slight as to be unmeasurable, and most have been dry since the
second quarter of 1989. Specific conductivity of the water varies
from approximately 1100 to 1700 umhos/sec.
Potential impacts to ground water from the operation include:
- Lowering of water levels in the Burro Canyon aquifer;
- Contamination of the Burro Canyon aquifer;
- Lowering of water levels in alluvial aquifers of Bramiers Draw and
Section 33 Creek;
- Contamination of the same alluvial aquifers.
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