REP16829

• Permit No: C1981020
• IBM Index Class Name: Report
• Doc Date: 5/23/1996
• Doc Name: MCCLANE CANYON MINE C-80-004 MUNGER CANYON MINE C-81-020 1995 ANNUAL HYDROLOGY REPORT
• From: DMG
• To: DAN MATHEWS
• Permit Index Doc Type: HYDROLOGY REPORT
• Media Type: D
• Archive: No

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STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1 313 Sherman 51., Room 215

Denver, Colorado 80203 I~~
Phone: [phone] ~
FAX: [phone]
DEPARTMENT OF
NATURAL
RESOURCES

DATE: May 23, 1996 Roy Romer
Governor
tames S Lochhead

TO: Dan Mathews Eeemuve D~reaor
Michael B. Long
Division Duenor
FROM: Susan Bnrgmaier
RE: McClane Canyon Mine (C-80-.004)
Munger Canyon Mine (C-81-020)
1995 Annual Hydrology Report
I have completed a review of the surface water portion of the Annual Hydrology Report (AHR)
for the McClane Canyon and Munger Canyon Mines. I did not see a memo from you as to
whether you reviewed compliance with monitoring frequency for the sites. I did not review
whether Grand Valley Coal Company (GVCC) conducted all of the required monitoring at both
operations. I did, however, review the results of the monitoring reported, comparing that
information with baseline monitoring, monitoring since the operations were permitted, and the
predictions of probable hydrologic consequences (PHC). Based on that review, I have the
following comments. Since I just looked at the same information for the McClane Canyon
renewal, some of these comments are carried over from my memos to you on the renewal.
1. The PHC section of the McClane Canyon permit predicts impacts to surface water will
be minimal. The Munger Canyon permit predicts impacts to surface water will range
from insignificant to nonexistent. Neither permit quantifies predicted impacts. As such,
monitoring to date is consistent with predictions, in that there seem to be no noticeable
mine related impacts to East Salt Creek, to which both operations drain.
2. There have been increases in suspended solids, both upstream and downstream of the
mines, in response to large precipitation events. The precipitation data provided in the
Annual Hydrology Reports correlates large events with increases in suspended solids.
3. Dissolved solids have remained relatively .constant over the period of record. Increases
downstream are parallelled by upstream degradation in McClane Creek, Munger Creek,
and East Salt Creek.
4. As I mentioned in my May 16, 1996 memo to you regarding the McClane Canyon permit
renewal, GVCC does not monitor flow at SW-8. In accordance with Rule
2.05.6(3)(iv)(C), and to make the surface water quality information more meaningful, flow
must be measured. Without flow measurement, if there were inconsistencies in quality