PERMFILE139282

• Permit No: M2005071
• IBM Index Class Name: Permit File
• Doc Date: 4/20/2006
• Doc Name: Rational for Recomendation for Approval Over Objections
• From: DMG sss
• To: File
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
7 313 Sherman St., Room 215 C C' L O RA D O
Colorado 80203
Denver DIVISION O F
, MIN
RAL S
Phone: [phone] E
FAX: (303) 832$106 G E O L O G Y
REC LAMATION•MINING
' SAfETT•SOENCE
DATE: Apri120, 2006
Bill Owens
TO: Steve Shuey Governor
Russell George
Executive Director
FROM: Allen Sorenson Ronald W. Cattany
Division Director
RE: Review of Rollins Sandstone C[iff Stability during Quarry Operations, Natural Resource Trustee
Benson Brothers, Red Shale Pit, File No. M-2005-071
The Division of Minerals and Geology (DMG) engineering staff have reviewed the following
documents relating to the potential for rock fall to be caused by operations at the proposed Red Shale
Pit/Quarry:
• Revey and Associates, Inc., "Impacts of Mechanical $quipment at Benson Brothers Proposed
Red Shale Quarry on Rock Bluffs," Report of Investigations, February 2006
• Gregory D. Lazear, "A Review of the Revey and Associates, Inc., Report of Investigations,"
April, 11, 2006
• Robert Flinn, "Memo to Greg Lazear, Red Shale Quarry Report," April 10, 2006
• Gregory D. Lazear, "Follow up Letter to: A Review of the Revey and Associates, Inc., Report
of Investigations," April, 13, 2006
• Paul Peter Urone and Patricia Urone, "Objection to the Benson Brothers Red Shale Quarry in
Coalby Canyon," April 18, 2006
• Revey and Associates, Inc., "Response to concerns regarding the Seismic Stability of the
Rollins Sandstone Bluffs adjacent to the proposed Red Shale Quarry in Delta County, CO"
April 19, 2006
While DMG recognizes that the additional vibration analysis rigor suggested by objectors to the DMG
recommendation to approve the permit application has some scientific merit, it is DMG's
determination that additional pre-mining investigations are unnecessary to assure that offsite damage
will be prevented.
DMG has considerable experience in similar quarry proposals, where the potential for quarry
operations to cause damaging rock fall has been evaluated. In particular, the South Table Mountain
Quarry application (file no. M-1992-112) was denied, in part, because the potential for the proposed
operation to exacerbate rock fall had not been sufficiently resolved. Similarly, operations at the
Summit Pit (file no. M-1988-102) were curtailed and eventually terminated, partly due to the inability
of the Operator to demonstrate that damaging rock fall would not result from on-going operations.
One of the chief differences between these quarries and the proposed Red Shale Quarry is that both
South Table Mountain and the Summit Pit would use blasting to fragment rock for further processing.
Office of Office of Colorado
Mined Land Reclamation Active and Inactive Mines Geological Survey