REV105747

• Permit No: C1996083
• IBM Index Class Name: Revision
• Doc Date: 1/19/1999
• Doc Name: MEMO BOWIE 2 MINE PN C-96-083 TR 7
• From: DMG
• To: JOE DUDASH
• Type & Sequence: TR7
• Media Type: D
• Archive: No

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STATE OF COLUI~UO
DIVISION OF MINERALS AND GEOLOGY
Deparlmenl of Nalu ral Resources
131 3 Sherman 51 . Rwm 215
Denver, Colorado 80203
Phone: [phone]
FAX: 13031 K72 B1 U6
INTEROFFICE MEMORANDUM
TO: Joe Dudish v
FROM: Mike Boulay fJ16
DATE: January 19, 1999
SUBJECT: Bowie No.2 Mine, Permit No. C-96-083, Technical Revision No. 7
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DEPARTMENT Of
NATURAL..
RESOURCES
Roy Romer
Gmernor
lames 5 Lochhead
E3eculive Dimrfor
Michael B. Long
Division Dueaor
As requested, I have reviewed the Bowie No. 2 TR-07 submittal as it relates to groundwater issues.
I have reviewed the entire submittal, the permit document, and the 1997 AHR. Based on my review,
I have the following comments concerning the adequacy of the TR-07 submittal.
Five drill holes completed in the "D" seam have been converted to monitoring wells. Of
these five, four wells (DH-l~, DH-16, DH-25, and DH-49) are included in the current
groundwatermonitoringprogram. Groundwater flow direction in the coal bearing member
of the Mesaverde Formation in the area of [he longwall panels is to the north. All of the "D"
seam wells included in the monitoring program are located up gradient of the proposed
longwall panels. DH-13 (completed in the upper portion of the "D" seam) is located
immediately downgradientof the proposed panels. However, no monitoring data have ever
been provided for this well and the well has since filled with mud.
Because the abandoned mine workings are expected to fill with groundwater, the potential
exists for future migration of mine inflow water to off-site areas down gradient of the mined
out panels. Although the saturated portions of the coal bearing member of the Mesaverde
Formation may transmit only small quantities of water, secondary porosity may result in
significant quantities of groundwater migrating dowrrgradient away from the mine workings.
The concern is- that this water would likely contain high levels of total dissolved solids
(TDS) and may discharge as seeps and springs particularly along the coal outcrop north of
the mine workings along Hubbard Creek. This may also increase the potential for landslides
in this area. The existing monitoring program does not adequately quantify impacts due to
the potential for mine discharge via the coal bearing strata and/or surrounding strata.