2012-03-28_REVISION - M1977300

• Permit No: M1977300
• IBM Index Class Name: REVISION
• Doc Date: 3/28/2012
• Doc Name: DRMS RESPONSE TO COTTER LETTER OF MARCH 1ST, 2012
• From: DRMS
• To: COTTER CORPORATION
• Type & Sequence: AM4
• Email Name: TAK
• Email Name: AJW
• Media Type: D
• Archive: No

iDIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
► 4 (V1arch 28, 2012
John S. Hamrick
otter Corporation
P.O. Box 1750
Canon City, CO 81215
/
Re: Schwartzwalder Mine, Permit No. M- 1977 -300
..-DRMS response to Cotter letter of March 1, 2012
Dear Mr. Hamrick:
STATE OF COLORADO
*OW
DRMS has received your letter of March 1, 2012 which, in part, expresses Cotter's desire to
propose onsite disposal of alluvial source term materials from the mine. DRMS agrees that
Cotter should have the opportunity to propose onsite disposal of alluvial source term materials,
including disposal at a location inside the Schwartzwalder Mine workings or in a waste rock pile
on the land surface. Such a disposal plan must be submitted as a permit amendment and will
need sufficient detail to demonstrate that disturbances to the prevailing hydrologic balance will
be minimized. To allow for such a plan, please revise item 6 in Attachment A of our letter of
January 30, 2012 as follows.
6. Integrate a plan into the EPP for disposal of the alluvial source term materials, including a
cost estimate of completing the plan. If the proposed disposal method is a fill structure
within the mine workings or is a fill structure in an onsite waste pile, then please provide in
the plan a detailed engineering design that includes:
Office of
Mined Land Reclamation
a) Two vertical cross - sections oriented perpendicular to each other that are drawn through
the fill and surrounding rock at a scale sufficient to show details of the final fill structure
and any installed moisture barriers,
b) A structural stability analysis of the fill structure that demonstrates long -term stability,
c) A drainage plan demonstrating that ground water or meteoric water that infiltrates into
the subsurface will not saturate any part of the fill structure,
<4 i< 1 A W
C0
D I V I S I O N O F
RECLAMATION
MINING
— &—
SAFETY
John W. Hickenlooper
Governor
Mike King
Executive Director
Loretta E. Pineda
Director
d) A predictive geochemical model of expected water quality demonstrating that, should the
fill drainage plan fail, saturation of the fill by meteoric water or ground water will not
result in degradation of the quality of the mine pool water, ground water, or surface
water,
Office of
Denver • Grand Junction • Durango Active and Inactive Mines