PERMFILE67922

• Permit No: M2005045
• IBM Index Class Name: Permit File
• Doc Date: 1/13/2006
• Doc Name: Review of Proposed Gravel Pit Access Road Gravel LLC
• From: DMG acs
• To: DMG
• Media Type: D
• Archive: No

STATE OF COLOIZ~DO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman St, Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: (30}) 832-8106
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JAN' ~ 1~
~ivtston of Minerals eaI GeWogY
COLORADO
DIVISION O F
MIN&RALS
GEOLOGY
0.ECLAMATIOMMINING
SAFETY•SUENCE
DATE: 7anuary 13, 2006
TO: Kate Pickford
FROM: Allen Sorenson
RE: Review of Proposed Gravel Pit Access Road, Gravel, L.L.C.,
Rock Dog No. 1 Pat, Fite No. M-2005-045
Bill Owens
Governor
Russell George
Executive Director
Ronald W, Cattany
Division Director
Natural Resource Tmstee
The Applicant for the Rock Dog No. 1 Pit has proposed the construction of an access road that would
traverse a relatively steep slope down from Airport Road, located on a high terrace above the Florida River,
to a lower terrace where mining operations are proposed. In June of 2005, Andy Gleason, a geologist with
the Colorado Geological Survey, inspected the location of the proposed access road, and made the
following comments in a June 30, 2005 letter to the La Plata County Planning Department:
The access road from (Airport Road) to the bottom of the floodplain adjacent to the Florida River
cuts across slopes of 30% or greater.
There are a few concerns I have with the construction of this road. The first is slope stability in the
vicinity of the Williamson residence. The access road is proposed to run below the residence, which
sits very close to the edge of the top of the slope. Over-steepening of the slope below the residence
has the potential to cause slope instability and possibly have a negative effect on the Williamson
house.
There are wet areas on the slope below the proposed access road that may be wetlands. These wet
areas can affect the slope stability, especially with over-steepened road cuts and heavy truck traffic.
A slope stability analysis should be performed on the slope crossed by the access road which
includes the wet areas in the analysis.
In conclusion, a slope stability analysis should be performed on the slopes crossed by the access
road. A wetlands evaluation should be performed prior to the slope stability analysis so that the
water mass maybe included in the slope stability analysis.
In order to investigate slope stability concerns with the proposed access road, the Applicant engaged
Trautner Geotech of Durango, Colorado to complete a geotechnical investigation of the slope. This
investigation resulted in the issuance of a Trautner Geotech report dated October 21, 2005 and titled
"Geotechnical Engineering Recommendations for the Access Roadway to the Proposed Gravel LLC Gravel
Pit" (Trautner Report). In addition to the Trautner Report, the Division of Minerals and Geology (DMG)
engineering staff also reviewed the following documents:
Office of Office of Colorado
Mined Land Reclamation Active and Inactive Mines Geological Survey