2008-04-15_REVISION - M1980244 ‎(256)‎

• Permit No: M1980244
• IBM Index Class Name: REVISION
• Doc Date: 4/15/2008
• Doc Name: VOL V APP 8 Valley Leach Facility Phase 5 Extension Design
• From: CC & V
• To: DRMS
• Type & Sequence: AM9
• Media Type: D
• Archive: No

SMITH WILLIAMS CONSULTANTS, INC.
Colorado will be on site to observe and/or provide testing for vegetation and soil removal;
underground working remediation, subgrade preparation, fill placement, SLF placement,
underdrain and leak detection system installation, geomembrane installation, and LVSCF and
DCF placement. Technical specifications for Phase 5 VLF are included in Appendix H. The
earthwork and geomembrane test results and locations will be summarized in an as-built report
certified by a professional engineer registered in the state of Colorado, a copy of which will be
forwarded by CC&V to the DRMS for acceptance.
4.2 Site Layout
The design and layout of Phase 5 VLF were developed to achieve several key objectives. The
first objective was to provide a geotechnically stable layout, such that acceptable slope stability
factors of safety-(FOS) can be achieved. The second objective involved developing an effective
remediation program for the underground workings located within the Phase 5 VLF footprint
area. The third objective included providing adequate capacity for ore reserves.
4.3 Staged Construction
.The engineering designs contained in this document provide a detailed description of the project
features associated with the proposed extension. In instances where the submittal of further
information is warranted, Smith Williams understands that CC&V will provide issued-for-
construction (IFC) drawings and appropriate supporting documentation (e.g., calculations,
narrative explanations, etc.) to the DRMS containing design details and changes that are based
on site-specific conditions and constraints. Comparable to Amendment No. 8 activities,
submittal of the IFC drawings and any supporting information is not expected to require new
approvals but is intended solely to ensure that the DRMS is aware of the phased implementation
of the proposed extension activities.
The Phase 5 VLF will likely be constructed over a period of 3 to 4 construction seasons, but
could be constructed in a shorter or longer period at CC&V's discretion. Development of
construction limits will be dependent on a number of factors including, but not limited to,
-climatic conditions, mine sequencing, contractor availability, and other related factors.

4.4 Valley Leach Facility (VLF) Foundation
Preparation of the Phase 5 VLF foundation includes clearing and grubbing, placing compacted
structural fill during site grading, .and placing SLF. The overall Phase 5 VLF site-grading plan is
presented on Drawing A220. The site-grading plan was developed to provide a stable VLF
foundation while promoting internal drainage to the PSSA. The Phase 5 VLF grading plan has
S:\PROJECTS\1125 CC&V PHASE 5 VLF\H2 - DESIGMAREQUA VLF\VLF PHASE 5 FINAL REPORT V2.DOC 21