GENERAL45604

• Permit No: M1980244
• IBM Index Class Name: General Documents
• Doc Date: 2/7/1995
• Doc Name: REEVALUATION OF AMENDMENT 6 LEACHING TEST CRESSON MINE CRIPPLE CREEK AND CRIPPLE CREEK & VICTOR
• From: DMG
• To: BERHAN KEFFELEW
• Media Type: D
• Archive: No

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DIVISION OF MINERALS AND GEOLOGY
Depanmenl of Natural Resources
1713 Sherman St., Raom 215
Denver, Colorado 80203
Phune: [phone]
FAX: [phone]
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999
STATE OF COLORADO
II~~~
DEPARTMENT OF
NATURAL
RESOURCES
Roy Romer
Governor
lames 5. Lochhead
DATE: February 7, 1995 Executive Director
MichaCl B. Long;
Division Director
TO: Berhan Keffelew ~,5
FROM: Harry Posey and Bill Yo -Feirn `~
RE: Reevaluation of Amendment # 6 leaching tests; Cresson Mine, Cripple Creek and
Victor Gold Mining Company, Permit No. M-80-244
The following memorandum encapsulates our reevaluation of the Amendment #6 leaching test results,
CC&V's response, Kim Lappako's letter, and David Hyatt's third pally evaluation. If you wish to
have more detailed inforntation, please contact us.
BACKGROUND
Amendment #6 to the Cresson permit was approved contingent on receipt of certain ore and waste rock
leaching tests and acceptance by the Division that the results of those tests indicated that effluents
would be benign. Based on the results of [he leach tests, we determined that some of the ore and
waste rock at the existing and proposed Cresson facility has the potential to generate acid and metals.
METHODS
We evaluated the results of the leaching studies based on surface water standards for (1) segment 21
of the Arkansas River as described in the January 31, 1995 letter from WQCD, (2) Cripple Creek as
described in Appendix 11 of the Sept 30 response to OMLR Technical Review, (3) State agricultuFal
standards, (4) State drinking water standards, and (5) standards for the Carlton Discharge. Table III-1
from the WQCD Rationale for Permit No. CO-0043648 (attached) identifies which standards were
evaluated.
Our assessment was based on simple exceedances. We assumed no dilution from other surface water,
and assumed that no metals would precipitate out of solution within the process water gain.
REVIEW
Upon review of the documents by Lapakko and by Hyatt, and after re-examining the data in light of
the proposed surface water quality control standards, it is evident that all of the reviewers have come
to the same general conclusion. That conclusion is as follows.