2010-10-04_PERMIT FILE - M2009076

• Permit No: M2009076
• IBM Index Class Name: PERMIT FILE
• Doc Date: 10/4/2010
• Doc Name: Adequacy Review #2 & Tailings Impoundment Design
• From: DRMS
• To: Venture Resources, Inc.
• Email Name: JLE
• Email Name: AJW
• Email Name: PSH
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY t
Department of Natural Resources J
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
/October 4, 2010
Ryan McHale, PE
1/enture Resources, Inc.
COLORADO
D IV IS I ON OF
RECLAMATION
MINING
SAFETY
Bill Ritter, Jr.
Governor
Mike King
Executive Director
P.O. Box 1974
Loretta E. Pineda
Idaho Springs, CO 80452 Director
RE: Hukill Gulch Millsite; File No. M-2009-076. Adequacy Review #2 & Tailings Impoundment
Design
Dear Mr. McHale,
The Division received your letter dated October 1, 2010 and September 14, 2010 in regards to
acceptable outslope angles for the mill tailings impoundment. After our meeting on September 30,
2010, the Division re-analyzed the proposed tailings impoundment design and stability of the proposed
impoundment to determine if a different outslope angle could be accepted. After careful consideration,
the Division maintains its stance outlined in the second adequacy review letter dated September 8,
2010. The long-term stability of the proposed upstream impoundment cannot be assured due to the
potential for liquefaction during an earthquake. The outslope angle of the impoundment is not the
limiting factor of the design.
The Division believes there are several options the Applicant should consider, if they decide to proceed.
They are summarized below:
1.) Submit a technical revision to the permit application for limited mill tailings disposal in Hukill
Gulch impounded by conventional earthen damming, such as the barrier bench described in the
permit application.
2.) Submit an amendment to the permit application to impound the mill tailings in multiple
conventional earthen dam embankments.
3.) Submit an amendment to the permit application to impound the mill tailings using a different
embankment raising method, such as downstream raises.
4.) Submit an amendment to the permit application to use a cemented paste technology to stabilize
the mill tailings. However, as discussed in the second adequacy review, the paste technology
may not resolve the liquefaction issue, and would exacerbate the revegetation problem and
would likely require a plan for placement and anchoring of growth medium. Also, the Operator
would likely have to import enough growth medium to support a rangeland plant community.
Along with these options, the Operator will need to submit the information and address the remaining
issues identified in the second adequacy review letter dated September 8, 2010. In accordance with
Rule 1.8.1, the Applicant may amend, or make technical revision to application for a permit under
consideration by the Office by filing a copy of such amendment or technical revision with the Office and
placing a copy with the County Clerk and Recorder. Any amendment or technical revision to an
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