PERMFILE46153

• Permit No: M2005033
• IBM Index Class Name: Permit File
• Doc Date: 8/30/2006
• Doc Name: Mining Setbacks from Permanent Valuable Man-made Structures
• From: DRMS rmw
• To: DRMS
• Media Type: D
• Archive: No

STATE OF COLORADO
DIVISION OF RECLAMATION, MINING AND SAFETY
Department of Natural Resources
1313 Sherman S[., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
Date: August 30, 2006 /
To: Erica Crosby's
From: Rick Wenzel
COLORADO
DIVISION OF
RECLAMATION
MINING
- &-
SAFETY
Bill Owens
Governor
Russell George
Executive Director
Ronald W. Gattany
Division Direcor
Natural Resource Trustee
RE: i~'lining Setbacks from Permanent Valuable Manmade Structures, Coulson Excavating Co.,
Inc., Gardels Pit, DBMS Permit No. M-2005-033 t/
As requested, I have reviewed the slope stability analysis prepared by WSI Weiland, Inc. (Weiland) on behalf
of Coulson Excavating Co., Inc. (Coulson) and submitted to the Division on August 7, 2006 as part of
Coulson's Regnlaz 112 Permit Application for the Gazdels Pit, DRMS Permit No. M-2005-033.
The purpose of the slope stability analysis was to demonstrate that the proposed mining activities would not
adversely affect the stability of any significant, valuable and permanent man-made structures located within
two-hundred feet of the affected land, in accordance with Rule 6.4.19 of the Mineral Rules and Regulations of
the Colorado Mined Land Reclamation Board for The Extraction of Construction Materials (Rules).
Based on a review of Exhibit C-2, Mine Plan Map, submitted with the permit application, the City of
Loveland, Colorado owns a wastewater treatment plant that is located within two-hundred feet of the proposed
west permit boundary for Cell B of the proposed mining operation. The Division understands that the City of
Loveland declined to provide the applicant with a notarized letter stating that the proposed mining and
reclamation activities will have "no negative effect" on their utility. Therefore, the applicant has provided the
Division with the aforementioned engineering evaluation to satisfy the requirements of Rule 6.4.19.
The slope stability analysis submitted as the Geotechnical Stability Exhibit ofthe permit application evaluated
the stability of a O.SH:1 V slope with a forty foot setback from the permit boundary (approximately fifty feet
from the wastewater treatment plan). Using conservative soil properties previously suggested by the Division,
the analysis resulted in a Factor of Safety (FOS) of 1.01, indicating that the slope should be stable under the
modeled conditions and that the proposed mining activities should not adversely affect the stability of the
adjacent wastewater treatment plant. To confirm this result, I performed an independent analysis using the
same soil profile and soil properties. The result I obtained from my analysis was similar to the result obtained
by Weiland. Therefore, it is my opinion that the applicant has satisfied the requirements of Rule 6.4.19.
Should you have any further questions regarding this issue, please feel free to contact me.
Cc: Carl Mount, DRMS
Attachments: DRMS Slope Stability Analysis
Office of Office of
Mined Land Reclamation Arrive and Inactive Mines