GENERAL36516

• Permit No: C1981010
• IBM Index Class Name: General Documents
• Doc Date: 10/30/2006
• Doc Name: Additional Information Request Re 10/8/06 Landslide
• From: DRMS
• To: Trapper Mining Inc.
• Permit Index Doc Type: General Correspondence
• 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]
October 30, 2006
Mc Forrest Luke
Trapper Mining, Inc.
F.O. BOX 187
Craig, CO 81626
Re: Additional Information Request, October 2006 Landslide,
Trapper Mining Inc., CDRMS Permit No. C-1981-010
Dear Mr. Luke:
COLORADO
DIVISION O F
RECtaMArloN
MINING
- &-
SAFETY
Bill Owens
Gavemor
Russell George
Execu[ive DIreC(OI
Ronald W. Cattany
Division Director
Natural Resource Trustee
On October 8, 2006, a landslide occurred at the Trapper Mine in an area referred to by Trapper Mining Inc
(TMI) as the East Panel Area. This landslide was reported to the Division of Reclamation, Mining and
Safety (Division) on October 9, 2006. The Division conducted an on-the-ground inspection of the
landslide on October 10-12, 2006. During this inspection, TMI personnel provided Division personnel
with information pertaining to water levels, pumping rates, and head levels in certain East Panel Area
dewatering wells. The Division subsequently conducted an aerial inspection of the slide on October 13,
2006, obtaining 38 photographs of the landslide so as to better examine the extent of the landslide.
The Division conducted a second on-the-ground inspection of the landslide on October 17, 2006. During
this inspection, TMI personnel provided Division personnel with four maps. These maps are entitled
"Geotechnical Monitoring Dewatering Wells & Continuous Core Holes (10/17/06)", "Gd Pit -Cut 2 -
Plan & Profile (1/30/06)", "K/MK Roof (undated)", and "L/ML Roof (undated)".
After review of the information obtained during these three inspections and of other materials in our
offices, the Division requests the following:
1. Please provide the Division with a forensic geotechnical and engineering analysis that
characterizes the landslide and its causes. In this analysis, please provide and evaluate the
following:
Blasting records from all blasts conducted at the Trapper Mine from September 24, 2006 to
October 9, 2006. The geotechnical and engineering analysis should include reconstructions
of each of the blasts detonated during this period to determine the maximum peak particle
velocities achieved in the area of the landslide, and to determine compliance with the
maximum weight of explosives regulatorily allowed to be detonated within any 8-
millisecond period within each blast. The geotechnical and engineering analysis should
include a determination of whether ground vibration from blasting contributed to, or
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Mined Land Reclamation Active and Inactive Mines