2009-02-24_PERMIT FILE - M2008080

• Permit No: M2008080
• IBM Index Class Name: PERMIT FILE
• Doc Date: 2/24/2009
• Doc Name: Review of the Slope Stability Report
• From: DRMS-acs
• To: DRMS-mac
• Email Name: MAC
• 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] DIVISION O F
RECLAMATION
FAX: [phone] MINING

SAFETY
Bill Ritter, Jr.
Governor
DATE: February 24, 2009 Harris D. Sherman
Executive Director
TO: Michael Cunningham
Ronald W. Cattany
Division Director
FROM: Allen Sorenson Natural Resource Trustee

RE: Review of the Slope Stability Report, Journey Ventures, LLC,
Journey Ventures Pit, File No. M-2008-080
The Division of Reclamation, Mining, and Safety (DRMS) engineering staff has completed a review of the
slope stability report included with the above referenced permit application. The application states that the
pit will be mined such that at no time will any excavations be steeper than 2H:1 V. The majority of the
excavations will be in the dense sand and gravel deposit present at the site. 2H:1 V slopes in bank sand and
gravel are inherently stable, and therefore, the DRMS concurs with the conclusions in the slope stability
report that surrounding structures will not be affected by land sliding of the excavated pit walls. In fact,
depending on the applicant's response to item nine in the DRMS February 4, 2009 preliminary adequacy
review letter, most of the excavations in the pit will be no steeper than 3H:1 V. Since the stability of
surrounding structures is dependent on the excavation of pit walls no steeper than 2H:1 V, the DRMS will
consider excavations steeper than 2H:1 V at any point during mining to be a serious violation of the terms
of the permit, if granted.
The application states that there are gas and water pipelines located near the proposed pit. For pipelines,
the DRMS is concerned not only with the potential for landslide failure to damage the structure, but also
with the potential for the pipeline to be damaged by flexure caused by slight earth movements caused by
lateral stress relief through the excavation adjacent to the pipeline. DRMS frequently requires that strain
gauges be installed on pipelines adjacent to pits to monitor for flexure. The applicant must provide the
following information about the pipelines before a determination can be made about the need for
monitoring:
1. Pipeline material, diameter, and wall thickness.
2. Burial depth.
3. Pressure and flow rate.
Enclosed with this memo is information about pipeline monitoring that may be required if it is determined
to be necessary.
enclosure(s)
c:\acs files\My Documents 4-19-06 thru\joumey ventures stability review.doc
Office of Office of
Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines