2009-08-06_REVISION - C1982056

• Permit No: C1982056
• IBM Index Class Name: REVISION
• Doc Date: 8/6/2009
• Doc Name: Preliminary Adequacy Review ‎(Memo)‎
• From: Marcia Talvitie
• To: Janet Binns
• Type & Sequence: TR67
• Email Name: JHB
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman St., Room 215
Denver, Colorado 80203 COLORADO
[

Phone: [phone] D I V I S I ON O F
RECLAMATION
FAX: [phone] MINING
INTEROFFICE MEMORANDUM SAFETY
Bill Ritter, Jr.
Date: 06 August 2009 Governor
Harris D. Sherman
To: Janet Binns, Lead Specialist Executive Director
Ronald W. Cattany

From:
Marcia L. Talvitie, P.E. Division Director
Natural Resource Trustee
Subject: Permit No. C-1982-056 - Foidel Creek Mine
TR-67 - Expansion of Coal Refuse Disposal Area
Preliminary Adequacy Review - Engineering
Per your request for assistance, dated 6/26/2009, I have reviewed the application for TR-67
submitted by Twentymile Coal Company (TCC) for expansion of the Coal Refuse Disposal Area
(CRDA) at the Foidel Creek Mine from the currently permitted 3 million cubic yard capacity to a
capacity estimated at 20 million cubic yards. Specifically, my review has focused on Rules
4.09.1, 4.09.2, 4.10 and 4.11.
Rule 4.09 - DISPOSAL OF EXCESS SPOIL
Rule 4.09.1 - General Requirements
The application adequately addresses the requirements of this section, with the exception
of (11).
Please refer to the comments regarding Rule 4.10.2, below.
Rule 4.09.2 - Valley Fill
"Valley Fill" is defined as follows: "a fill structure... that is placed in a valley where
side slopes of the existing valley measured at the steepest point are greater than 20-
[2.75:1, or 36.4%] or the average slope of the profile of the valley from the toe of the fill
to the top of the fill is greater than 10- [5.67:1, or 17.6°/x]".
Based on slopes and gradient information provided in the application, the Division
concurs with TCC's assertion that the proposed CRDA expansion does not meet the
definition of a Valley Fill.
Rule 4.10 - COAL MINE WASTE BANKS
4.10.2 [and 4.09.1(11)] - Site Inspection
Page 11 of the Geotechnical and Hydrological Report prepared by NWCC describes in
detail the inspection and testing schedule that NWCC recommends for construction of the
expanded CRDA. This schedule complies with the requirements of Sections 4.10.2 and
4.09.1(11). The Division did not observe that these recommendations have been included
as commitments by the operator within the revised pages of Section 2.05. The last
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Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines