2009-08-18_REVISION - C1980001

• Permit No: C1980001
• IBM Index Class Name: REVISION
• Doc Date: 8/18/2009
• Doc Name: Review Memo
• From: Tom Kaldenbach
• To: Jason Musick
• Type & Sequence: TR48
• Email Name: JDM
• Media Type: D
• Archive: No

R
STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
COLORADO
D I V I S I ON OF
RECLAMATION
MINING
SAFETY
Bill Ritter, Jr.
Governor
MEMO Harris D. Sherman
Executive Director
Date: August 18, 2009 Ronald W. Cattany
Division Director
From: Tom Kaldenbach Natural Resource Trustee
To: Jason Musick
Re: Edna Mine (C-80-001), TR-48
I have concluded the proposed termination of ground water and surface water monitoring at the Edna
Mine is warranted, based on the following observations. If final bond release is delayed, then the operator
may need to resume at least some of the monitoring.
Basic Standards (Interim Narrative Standard) for Ground Water (CWQCC regulation
41.5(C)(6))
The Edna Mine's alluvial ground water point of compliance is well TR-3, located approximately 600
feet north of the permit boundary. This well is completed in Trout Creek alluvium. In accordance with
41.5(C)(6)(b)(iii), sample data collected after January 31, 1994 is presumed to represent existing
ambient quality because no new disturbances have occurred since that date; therefore, currently
prevailing water quality is the applicable standard.
The Edna Mine does not have a ground water point of compliance for ground water in bedrock
stratigraphic units, based on the absence of the potential for the mine to negatively impact the quality of
bedrock ground water (memorandum in the mine's hydrology file, by Byron Walker of DRMS, dated
October 5, 2006). This conclusion was based on the likely head differential between spoil leachate and
bedrock ground water, and the lack of hydraulic communication between the leachate-saturated pits and
permeable bedrock stratigraphic units.
Instream Numeric Standards (CWQCC regulation 3.3.0)
The Edna Mine discharges surface runoff and spoil leachate into Segment 13c (Trout Creek above Fish
Creek) in CWQCC's Region 12 of the Yampa River basin. CWQCC Regulation 3.7.0 lists numeric
standards for 26 parameters on Segment 13c. The Edna Mine has sampled discharges from two outfalls
monitored under the Colorado Discharge Permit System (CDPS). A parameter is chosen for CDPS
sampling based on its potential for occurring in coal mine runoff and leachate, and its potential for
degrading instream water. Only one parameter in Edna's CDPS sampling program has an instream
standard (pH). The Edna Mine's CDPS samples have not exceeded the 6.5 to 9.0 pH instream standard
applicable to Segment 13c of Region 12.
As part of the monitoring required in the DRMS mine permit application, the mine has also sampled
instream quality for two additional constituents which have instream standards (NH3 and N02).
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Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines