GENERAL37354

• Permit No: M1980244
• IBM Index Class Name: General Documents
• Doc Date: 11/1/1994
• Doc Name: REVIEW ACID BASE POTENTIAL OF CRESSON MINE OVERBURDEN CRESSON PROJECT M-80-244
• Media Type: D
• Archive: No

•

STATE OF • III IIIIIIIIIIIIIIII
999
COLORADO
DIVISION OF MINERALS AND GEOLOGY
Depanmenl of Natural Resources
1313 Sherman 51., Room 215 J
F

Denver, Colorado 80203 I~
~~
I
Phone: [phone] I
FA%: (3031 832-8106
DEPARTMENT OF
NATURAL
RESOURCES
Roy Romer
Governor
DATE: November 1 1994
~ lames 5. Lochhead
Execmrve Dvec~o~
Michael B. Long
TO: Berhan Keffelew Drcivon Director
FROM: Harry Posey and Bill York-Feirn " I
RE: Review: Acid-Base Potential of Cresson Mine Overburden; Cresson Project,
M-80-244
GENERAL OBSERVATIONS
Part of CC&V's conclusions, and procedural decisions depending on those, are not supported
by the data disclosed. CC&V was cautioned to analyze the humidity cell leachates with an eye toward
surface water quality standards. Required detection levels should have been at or below water quality
table value standards. In general, this was not done.
CC&V has taken an approach to data interpretation that will probably not be acceptable either
to DMG or to CDPHE. They conclude that the "ambient" water quality measured at Arequa Gulch
WQCD Station 111 is the criterion to aim for in terms of water quality. And this conclusion is drawn
even though many of the surface water quality measurements at AG-1 are not in compliance with the
Water Quality Standards. Of course, the DMG does not set or enforce water quality standards.
However, the DMG does require that as a condition of minimization of impacts to the hydrologic
balance, that operators must meet all other Local, State and Federal requirements. In that regard, the
criterion upon which the DMG must measure effluents generated within the mine permit boundary is
surface and ground water quality standards. Thus, until the CDPHE indicates otherwise, process
waters that do not meet water quality standards must be controlled by the operator, either from
forming or from discharging.
EXECUTIVE SUMMARY
CC&V anticipates that open pit mining will not adversely modify the current water=quality of
water emanating from the Cripple Creek Mining District. They propose to segregate high pyrite
overburden [i.e. waste] by placing it in the Ironclad and Globe Hill mines and the Cresson mine.
They propose further to monitor water quality in the Arequa Gulch overburden storage area.