REP39665

• Permit No: C1981044
• IBM Index Class Name: Report
• Doc Date: 11/24/1995
• Doc Name: 1994 AHR Review: internal memo
• From: DMG
• To: ERICA CROSBY
• Permit Index Doc Type: Hydrology Report 1994
• Media Type: D
• Archive: No

III IIIIIIIIIIIIIIII
STATE OF COLOIZP~UU
DIVISION OF MINERALS AND GEOLOGY
Department of Nalu rat Rewurces
1313 Sherman 51., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
To: Erica Crosby
From: Barbara Pavlik
Date: November 24, 1995
Re: Annual Hydrology
Eagle Mine (C-81-044)
~~
DEPARTMENT OF
NATURAL
RESOURCES
Roy Romer
Governor
lames S Lochhead
Enec uu ve Dvrc~or
Michael B Long
Drvis ion Director
I have reviewed the groundwater portions of the F~nnual Hydrology
Report for the Eagle Mine. A summary is presented below:
1) The report was well organized and thorough.
2) Bedrock Groundwater Levels:
Trout Creek Sandstone: Both of the monitoring wells
completed in the Trout Creek Sandstone had bc~en used as
pumping wells. Both wells have experienced a :recovery in
water level which the operator attributes to a reduction
in pumping. Both wells have experienced about.a 200 foot
recovery from their maximum drawdowns. water levels are
about 45-70 feet lower than when monitoring began. The
Okie Plaza well was mined through in 1994.
Middle Sandstone: Water levels in the Middle Sandstone
appear to have been affected by mine dewatex•ing and by
subsidence. Water level fluctuations are greater in
wells which are in closest proximity to the mine
workings. The operator notes that the potentiometric
gradient trends south as a result of water :Level drops
above the longwall panels. However, the contours drawn
on the Middle Sandstone Potentiometric Surface Map
indicate more of a westerly flow. The oper<><tor should
clarify this. Also, the contour lines should be labelled
to avoid confusion.
Twentymile Sandstone: No long term trends in water
levels were noted in the Twentymile Sandstone. The
hydraulic gradient in this aquifer remains toward the
northwest.