2012-10-16_REPORT - C1981028 ‎(2)‎

• Permit No: C1981028
• IBM Index Class Name: Report
• Doc Date: 10/16/2012
• Doc Name: 2011 AHR Review ‎(Emailed)‎
• From: DRMS
• To: Don MacDonald & Savage
• Annual Report Year: 2011
• Permit Index Doc Type: Hydrology Report
• Email Name: JLE
• Email Name: SB1
• Media Type: D
• Archive: No

DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215 COL O RA D O
Denver, Colorado 80203 D I V I S I O N o l:
RECLAMATION
Phone: [phone] MINING
FAX: [phone] —&—
SAFETY
16 October 2012
John W. Hickenlooper
Governor
Donald MacDonald
Coors Energy* Company* Mike King
Executive Director
P.O. Box 467
Golden, Colorado 80402 Loretta Pineda
Director
RE: Keenesburg Mine; C- 1981 -028, 2011 AHR Review
Response to Coors Sep. 10th, 2012 Letter; Proposed Revegetation Success Standards Equations
Dear Mr. MacDonald,
The Division received your response to the review of the 2011 Annual Hydrology and Reclamation Report on
September 12, 2012. The Division conducted a preliminaiv review of the proposal to revise the predictive
equations used to project the revegetation success standards for cover and production at the Keenesburg Mine.
One item that will need to be addressed is an error in the precipitation value for the Near 1995. Based on the
Division's calculations it appears the precipitation amount from September of 1994 to July of 1995 should be
16.59 instead of the 16.77 as indicated in the response letter. This precipitation value modifies the predictive
equations slightly*.
The Division agrees with Mr. Savage's analysis that the correlation coefficients of the new predictive equations
are lower than the currently* approved equations. For the vegetation cover predictive equation, the currently*
approved equations yielded a correlation coefficient value of .9433; the new equation yields a value of .7698.
Similarly* for herbaceous production, the currently* approved equation yielded a correlation coefficient value of
.8948 and the new equation yields a value of .8414. Please provide documentation and rational that the
correlation coefficients yielded by the new equations are adequate.
This revision will need to be submitted in the form of a Technical Revision.
If you have any questions please feel free to contact me at (303) 866 -3567 ext. 8120.
Sincerely*,
f ) A gyj)K-
Jared Ebert
Environmental Protection Specialist, DRMS
CC: Brock Bowles, DRMS
Mike Savage, Savage and Savage via e -mail.
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines