2008-04-15_REVISION - M1980244 ‎(325)‎

• Permit No: M1980244
• IBM Index Class Name: REVISION
• Doc Date: 4/15/2008
• Doc Name: VOL II Appendix 2, Hydrologic Evaluation Report
• From: CC & V
• To: DRMS
• Type & Sequence: AM9
• Media Type: D
• Archive: No

Introduction
• Section 4.0, Grassy Valley Hydrologic Conditions - Presents a detailed
hydrologic assessment of the Grassy Valley drainage and the hydrologic
conditions anticipated from the proposed MLE activities. A discussion of the
potential hydrochemical effects of the proposed MLE activities is also provided.
Details and results of the field investigations within the Grassy Valley drainage
are presented. A water balance model has been prepared for the Grassy Valley
drainage, calibrated to current conditions, and used to evaluate the MLE
activities in the drainage. This water balance model is described and results of
the current, operational, and post mining simulations are presented. Potential
hydrological effects from the operational and design criteria for the proposed
ECOSA are also provided.
• .Section 5.0, Summary and Conclusions - Presents a summary of the document
and overall conclusions.
A separate report titled "Cresson Project Hydrogeochemical Evaluation" has been
prepared by Adrian Brown (Adrian Brown, 2008). That report addresses the
hydrogeological and geochemical properties associated with the proposed MLE.
1.1 Mine Life Extension activities summary
CC&V is submitting an application to extend mining in the existing Main Cresson Mine,
extend mining to the north in the WHEX portion of the East Cresson Mine, extend mining
to the north in the Schist Island portion and in the Globe Hill portion of the North Cresson
surtace mines, and to add capacity to the existing VLF. Overburden resulting from
mining in these extension areas will be placed into the existing Main Cresson Mine, East
Cresson Mine (including the WHEX portion), and North Cresson Mine as mine backfill or
placed for storage in the SGOSA, an extension of the SGOSA or the ECOSA. This MLE
will increase the anticipated mine life from 2012 to approximately 2016 and will extend
the duration of ore processing, as well. Figure 1.2 presents the general locations of the
current mine features and proposed MLE features.
Approximately 110 million tons of additional gold-bearing ore and approximately 250
million tons of overburden are contained within the proposed MLE areas. The ore
(including ore under the approved Amendment No. 8) will be crushed and processed
using the existing crushing and conveying facilities. Ore will be processed on the
existing Phase I, II, III and IV VLF as welt as the extension to the existing VLF (Phase 5)
and gold will be recovered in the existing process facility. The overburden will be
backfilled into other portions of the mine, along with rock from other mining areas
already approved under Amendment No. 8, to establish apost-mining topography as
shown in the proposed final reclamation plan. Up to approximately 50 million tons of
additional overburden may be placed in the extension of the SGOSA and up to
approximately 60 million tons of overburden may be placed in the proposed ECOSA.
The following project elements are proposed to be changed for the current Cresson
Project as part of the MLE project:
• The categories of affected acreage within the permit boundary.
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Cripple Creek & Victor Gold Mining Company
Water Management Consultants