2011-04-28_REPORT - C1982056

• Permit No: C1982056
• IBM Index Class Name: Report
• Doc Date: 4/28/2011
• Doc Name: 2010 AHR Review
• From: DRMS
• To: Twentymile Coal Company
• Annual Report Year: 2010
• Permit Index Doc Type: Hydrology Report
• Email Name: JDM
• Media Type: D
• Archive: No

undermined areas (well 93M001)
but not in areas beyond mining or
the permit area (well 008-7758.)
The Twentymile Sandstone water
levels at well 006-BRDH-7
remained relatively constant with
that of previous years, with no
mining impacts apparent. Levels
in well FBR-2 dropped 56 feet in
2003 and dropped another 84 feet
in 2005 which can be contributed
to the approaching 6 Right panel.
In 2005 water levels began to
recover and continue through
2010. Pumping for mine use of
Trout Creek sandstone wells 001-
83-106 and 001-83-107 is likely
the cause of a drop in the
potentiometric surface of the
Trout Creek sandstone at these
wells. These drops are likely a
local impact due to the proximity
of the two wells near the Trout
Creek sandstone's up-dip outcrop
belt. Therefore, the impact would
not be expected to extend beyond
the permit area. This appears to
be the case as localized
dewatering at well 001-83-106 has
stabilized in 2000 and continues to
be stable through 2010. A decline
of water level in well 001-83-107
continues to be the trend in 2010.
The Trout Creek Sandstone could
supply the needs of the
21. Prevention of postmining land uses of
impacts to ground CDRMS regulation pastureland and rangeland in the
water that adversely 4.05.11(2) YES permit area. Data from
impact post-mining land monitoring well 97013TC indicate
use mining has not impaired the use of
groundwater from the Trout Creek
Sandstone in the permit area.
22. Minimize The disturbance to the hydrologic
disturbance to CDRMS regulation balance within and adjacent to the
hydrologic balance 1(1)
4
05 YES permit area caused by mining and
within and adjacent to .
. reclamation at the Foidel Creek
the permit area Mine is the minimum that can be
expected from an underground