2008-05-09_PERMIT FILE - M2008010

• Permit No: M2008010
• IBM Index Class Name: PERMIT FILE
• Doc Date: 5/9/2008
• Doc Name: Review of exhibit
• From: DRMS
• To: DRMS
• Email Name: ACS
• 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
Phone: [phone]
FAX: [phone]
~ ~~ ~.
DATE: May 9, 2008
TO: Kate Pickford
COLORADO
D I V I S I O N O F
RECLAMATION
MINING
-&-
SAFETY
Bill Ritter, Jr.
Governor
Harris D. Sherman
Executive Director
Ronald W. Cattany
FROM: Allen Sorenson Division Director
~ ~~' ~ Natural Resource Trustee
:.~""~
RE: Review of Exhibit SyMcStone Aggregates, LLC, Mud Creek Pit, File No. M-2008-010 /
The Division of Reclamation, Mining, and Safety (DBMS) engineering staff have reviewed the following
documents:
• Exhibit S to the original Mud Creek Pit permit application.
• The application adequacy response letter from McStone Aggregates received Apri125, 2008.
• Revised Exhibit S received by email from Nathan Barton on Apri126, 2008.
None of these materials contain quantitative slope stability analyses to demonstrate that structures owned by
surrounding landowners will not be destabilized by excavation in the proposed pit. For the type of excavation
proposed, given the site stratigraphy, maximum pit depth, and that type of nearby structures that are present,
DBMS does not require quantitative slope stability analysis if the horizontal distance from the toe of any slope
excavated in the mining operation to any structure to be protected is at least twice the depth of the excavation.
This leaves only structures labeled E, M, and N on Map S-1 included in the original application as being of
concern for stability. The Applicant has three options to address the stability of structures E, M, and N.
1. Provide a notarized agreement between the Applicant and the persons having an interest in theses
structures that damage to the structures is to be compensated for by the Applicant.
2. Provide a clearly worded commitment that setbacks from these structures will be maintained at all times
during operations in the proposed pit such that the horizontal distance from the toe of any slope
excavated in the mining operation to any structure to be protected is at least twice the depth of the
excavation.
3. Provide quantitative slope stability analysis as a Geotechnical Stability Exhibit to the permit application
demonstrating that setbacks shown on the mining plan map are sufficient to protect the structures.
Since the excavation limits proposed for the Mud Creek Pit are different than the permit boundaries, it should be
reiterated to the Applicant that the mining limits shown on the Exhibit C maps and on map S-1 are enforceable,
and that mining beyond those limits, even if excavations remain within the permit boundaries, will be considered
a violation of the mine plan. Also, the mine plan allows for removal, relocation, and damage to structures
located within the permit boundaries during conduct of the mining operation. In order to approve a mine plan so
worded, even while recognizing that the landowners of the area to be permitted are the principles of McStone
Aggregates, the Applicant, a notarized agreement between the Applicant and the landowners stating that
damage to the structures is to be compensated for by the Applicant is required.
c:\acs files\My Documents 4-19-06 thru\mud creek ex s review.doc
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