GENERAL38943

• Permit No: M1980244
• IBM Index Class Name: General Documents
• Doc Date: 7/8/1994
• Doc Name: CRESSON PROJECT PN M-80-244 COMMITMENT 36 UNDERDRAIN MATERIAL INFORMATION ON SUITABILITY OF GRANITIC
• From: CRIPPLE CREEK & VICTOR GOLD MINING CO
• To: DMG
• Media Type: D
• Archive: No

//-~• Cripple Creek & Victor Gold Mining Company 999
l\ A Joint Ventun; -Pikes Peak Mining Company, Manager
"`~~~.t(1/// "~` 7// Operations Olflce Englewood Office
!\`~71T \V/ PO. Box 191, 2755 State Highway 67 5251 OTC Parkway, Suite 700, Englewood
Victor, Colorado 80860 Colorado 80111
[phone] • FAX [phone] [phone] • FAX [phone]
July 6, 1994
SENT BY FASCIMILE -COPY FOLLOWS BY OVERNIGHT MAIL
Mr. Berhan Keffelew
Environmental Protection Specialist
Colorado Department of Natural Resources
Division of Mines and Geology
Office of Mined Land Reclamation
]313 Sherman Street, Room 215
Denver, Colorado 80203
+~Ft;EiVF(~
JUL 81994
Q;v;S'on 01 iltul~;81•S d l.CrolrOY
Reference: Cresson Project: Permit Number M-80-244: Commitment Number "36"
(Underdrain Materiall -Information on Suitability of Granitic Material For
Use As Underdrain and Underdrain Pipe Bedding Material -Commitment
Number 32. Request to Modify Specification for Underdrain (maximum size).
Dear Mr. Keffelew:
The Cripple Creek & Victor Gold Mining Company ("CC&V") committed to utilizing
suitable rock materials for the underdrain in Commitment Number 32. In that commitment,
the Colorado Office of Mined Land Reclamation ("OMLR") has specified that the fill
materials used to construct the underdrain below the Arequa Overburden Storage Area and
the Cresson Heap Leach Facility be constructed from "durable, non-slaking, and chemically
inert" materials. More specifically, the Commitment reads:
"All urulerrlrain fill materials will be comprised of durable, non-slaking, and
chemically inert rock material, and must meet the gradation defined in the technical
specifications in this Application. !f any underdrain fill materials or soil liner
materials that have been placed are shown to be acid or toxin generators by the
geachemical evuhtarions acceptable to the Office, and such materials were placed
prior ro receipt of OMLR approval, materials pat meeting the criteria will be
completely removed, properly diseased of, and replaced with acceptable fill. The
technical specifications included in this Application (Volumes V and Vl, Appendix E;
February 28, 1994) are understood by CC&V to constitute et forceable permit
parameters. "
During the course of the Cresson Project it has been determined that granitic material (now
described upon examination as "granodiorite," selectively borrowed from within the limits of
the leach pad, should be used as the construction material to construct the underdrain. In
order to quantify the material as durable it was initially recommended by OMLR that LA
Abrasion and Slake Durability testing be performed. Concurrently Acid Base Accounting