2014-02-06_REPORT - M2010049

• Permit No: M2010049
• IBM Index Class Name: REPORT
• Doc Date: 2/6/2014
• Doc Name: Water information, second adequacy review
• From: DRMS/psh
• To: DRMS/tc1
• Email Name: PSH
• Email Name: TC1
• Media Type: D
• Archive: No

DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
STATE OF COLORADO
MEMORANDUM
To: Peter Hays, Environmental Protection Specialist
From: Tim Cazier, P.E., Environmental Protection Specialist _rL
Date: February 6, 2014
Re: Varra - Coulson Resource Project, Permit No. M- 2010 -049;
Exhibit G — Water Information, Second Adequacy Review
COLORADO
D I V I S ION OF
RECLAMATION
MINING
— St—
SAFETY
John W. Hickenlooper
Governor
Mike King
Executive Director
Loretta Pineda
Director
The Division of Reclamation, Mining and Safety engineering staff (DRMS) has reviewed the
following documents in response to our December 13, 2013 adequacy memorandum:
• January 13, 2014 response to DRMS comments to Mr. Garrett Varra from AWES, LLC,
• January 14, 2014 response memorandum from Mr. Douglas Trieste, Flow Technologies to
Messrs. Garrett Varra and Brad Jones, Varra Companies, Inc.,
• Drawing: Floodway and Erosion Mitigation Map, revised 1/7/14
• Drawing: Riprap Typical Section and Profile, revised 1/7/14
Shadow /Mounding Analysis Letter dated June 27, 2013 from Awes, LLC:
1. The letter focuses on Pit 112 and Pit 110. Response Comment #20 —The response does not
provide rationale for using an analysis from a different pit. The DRMS maintains that using
an analysis from a different site is of less value than modeling the subject site with less
certain data. No further response is necessary.
2. The DRMS questions the validity of the vector analysis. Also Response Comment #20 (2nd
paragraph) — this response requires some clarification:
a. The first assumption stated uses a seven -foot thick barrier wall. Typical clay liner
designs are only 3 feet thick. Please comment on the use of a seven -foot thick
liner.
b. The second assumption stated uses a constant head boundary inside the barrier
wall with an elevation of 4027 feet. Based on the drawing " Floodway and
Erosion Mitigation Map, revised 1/7/14 ", this is nearly 600 feet below existing
ground (crest elevation 4615). Please provide clarification or a corrected
elevation.
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines