2011-06-22_REVISION - C1981019

• Permit No: C1981019
• IBM Index Class Name: REVISION
• Doc Date: 6/22/2011
• Doc Name: Preliminary Adequacy Review No. 2 ‎(Memo)‎
• From: Marcia Talvitie
• To: Janet Binns
• Type & Sequence: PR3
• Email Name: JHB
• Email Name: MLT
• Email Name: SB1
• 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]
Rule 2.05.3 Operation Plan
Office of
Mined Land Reclamation
INTEROFFICE MEMORANDUM
Date: 22 June 2011
To: Janet H Binns, Lead Specialist
From: Marcia L. Talvitie, P.E.
Subject: Colowyo Mine — Permit No. C- 1981 -019 PR -03
Preliminary Adequacy Review No. 2— Engineering /Geotech
STATE OF COLOFADO
COLORADO
D I V I S I O N O F
RECLAMATION
MINING
—&—
SAFETY
John W. Hickenlooper
Governor
Mike King
Executive Director
Loretta E. Pifleda
Director
Pursuant to your request, I have conducted a review of the twice- revised (23 March and 28 May
2011) PR -03 application for the Collom area at the Colowyo Coal Mine. My review focuses on
the engineering and geotechnical aspects, specifically the haul and access roads, the sediment
ponds, and the temporary excess spoil pile. New questions are highlighted in blue.
1. Rule 2.05.3(2)(a) requires that a detailed narrative and appropriate maps be prepared,
describing the land to be affected within the permit area according to the proposed
sequence of mining and reclamation. Each narrative and/or map shall include a detailed
timetable sufficient to describe the various mining phases proposed. The Collom Mine
Plan is illustrated on Map 23B; Map 29B shows the proposed Spoil Grading by year.
When combined with information found on the Temporary Spoil Pile Design (Map 29C)
and the Little Collom Sump design, as illustrated in Exhibit 7 Item 26 Figure 2 (Fig. 2),
the overall sequence of activities for the Little Collom X Pit, the Temporary Spoil Pile,
and the Sump is not clear.
Map 29B appears to indicate that the X Pit will be entirely backfilled to grade by 2017.
However, the temporary spoil pile, which covers the southern portion of the pit, is not
scheduled for removal until the end of mining. Fig. 2 shows the Sump superimposed on
the X Pit shell, but does not address the condition that would exist if and when the pit is
backfilled with spoil and brought to final grade, nor does it show the presence of the
temporary spoil pile. Map 29C shows the temporary spoil pile superimposed upon the X
Pit shell, but the southern portions of the shell (beneath the pile) are not shown.
Please provide a clear narrative (with accompanying details on the maps, as
appropriate) of the proposed process: from excavation of the Sump, through mining of
Little Collom X Pit, phased construction of the temporary spoil pile, backfill of the
Little Collom X Pit, and final reclamation.
Office of
Denver • Grand Junction • Durango Active and Inactive Mines