2011-01-12_REPORT - C1981028

• Permit No: C1981028
• IBM Index Class Name: REPORT
• Doc Date: 1/12/2011
• Doc Name: 2009 AHR Review Letter
• From: DMRS
• To: Coors Energy Company
• Annual Report Year: 2009
• Permit Index Doc Type: Hydrology Report
• Email Name: RDZ
• Media Type: D
• Archive: No

Require-

Requirement Requirement
citation ment
complied
Comment
with?
(yes / no)
level identified in the 7/6/05 memo.
Each pit disrupts the potentiometric surface. After final
S. Restoration of backfilling, the pits can be expected to show full recovery
ground water CDRMS of the potentiometric surface outside of the pits and water
recharge to regulation yes table (unconfined) conditions inside the pits. No
approximate 4.05.11(3) significant formation of surface spoil springs is expected
premining rate due to the flat topography; therefore, there will be no loss
of ground water flows to surface waters.
The Probable Hydrologic Consequences section of the
permit application predicts no appreciable impacts to
T. Prevention of ground water systems outside the permit area. Water
adverse impacts CDRMS quality data from well DH-96 indicate there have been no
to ground water regulation yes adverse impacts to ground water in the Ennis alluvium and
systems outside 4.05.11 eolian sand outside the permit area, approximately 6,000 ft.
the permit area downgradient from the mine's pits.
The approved post-mining land use of most of the permit
U. Prevention of area is rangeland (a few acres are approved for
impacts to ground CDRMS commercial/industrial gas well use). As previously
water that regulations discussed, ground water in the Ennis alluvium and eolian
adversely impact 4.05
.1 and yes sand have not been adversely impacted by mining and
the postmining
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4
05 reclamation operations at the Keenesburg Mine. Ground
land use within .
. water in the Laramie coal and sandstone is not likely to have
the permit area had adverse impacts as explained in the previous discussion
of Basic Standards for Ground Water.
V. Minimization of
disturbance to the Changes to the hydrologic balance within and adjacent to the
hydrologic CDRMS
regulation es permit area, if any, would be the minimum that can be
balance within 4.05.1(1) y expected from a surface coal mining operation.
and adjacent to
the permit area
W. Prevention of
material damage CDRMS Previously discussed monitoring data and ground water
to the hydrologic regulation yes quality predictions indicate material damage has been
balance outside 4.05.1(1) prevented.
the permit area
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