REV100251

• Permit No: C1981038
• IBM Index Class Name: Revision
• Doc Date: 6/29/1994
• Doc Name: TR 25 WEST RIDGE WASTE PILE MODIFICATION ORCHARD VALLEY MINE C-81-038
• From: DMG
• To: STEVE SHUEY
• Type & Sequence: TR25
• Media Type: D
• Archive: No

- • • iii iiiiiiiiiiiii iii
999
STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Deparimenl of Natural Resources
1313 Sherman 51., Room 215
Denver, Colorado 80203
Phone: [phone]
FAY: [phone]
Date: June 29, 1994
To: Steve Shuey
II~~~
DEPARTMENT OF
NATURAL
RESOURCES
K , / Roy Romer
7 Governor
From: Kent Gorham
lames S. Lochhead
ErecWive Director
RE: TR-25, West Ridge Waste Pile Modification, Orchard Valley MJ~hlc4Qel e. Eong
#C-81-038 DIYISIOn DReCIUr
As per your request, I reviewed the information submitted attached
to your memo dated 6-21-94 for technical revision #25 (TR-25) for
the Orchard Valley Mine. My comments are as follows:
1. I approve of the elimination of the half-pipe and recommend
the installation of a vegetated ditch over this distance which
is sized for the 100-year, 24-hour event. I also understand
that the ditch below the road to the crushing and screening
level bench is part of the 100-year diversion which is
required for waste pile water diversion. This leaves a very
small area between the upper diversion and the pile which
drains to the upper toe of the pile. I will leave the
decision on whether this is a problem to you since I am
unfamiliar with the site, and in particular, this micro-area.
2. During my review, another issue came to light. Page 37 of
section 2.05.3, which was submitted with this revision, states
that a permanent diversion channel exists north of the mine
facilities area. This is incorrect and should be removed from
the permit text. Although this ditch may currently exist, it
is not part of the final drainage configuration as outlined in
the Final Abandonment Plan of the currently approved permit.
(Reference Map No. 6A-5D)
3. Another issue which should be considered at the next mid-term
or permit renewal is whether or not the existence of the waste
piles which are currently being constructed are being
considered in light of the final reclamation plan. These
piles and their associated drainage controls are a permanent
imprint on the current active mining surface and could easily
modify or change how the area will be reclaimed. In other
words, each time a waste pile is proposed or modified, the
final reclamtion plan must be considered to avoid future
problems. This becomes even more important when you consider
the associated bonding issues of having to regrade large areas
without the adequate bond monies available. (default scenario)
If you have questions let me know.