REV00811

• Permit No: M1982020
• IBM Index Class Name: Revision
• Doc Date: 9/12/1985
• Doc Name: LUCKY STRIKE MINE FN M-82-20
• From: QUATERNARY ENVIRONMENTAL CONSULTING
• To: MLR
• Media Type: D
• Archive: No

Quc>~ternlary III IIIIIIIIIIIIIIII SEP 1219~)~
L•nvirunmental Consulting; rr.»vE0 LANp
September QEQk~IylAT1ON OIVISIOPJ
Mr. Philip C. Saletta
Mined Land Reclamation
1313 Sherman St., Rm. 423
Denver, CO 80203
Re: Lucky Strike Mine; File No. M-82-20
Dear Phil:
On August 12, 1985, I inspected the above operation in Gunnison
County. The purpose of this visit was to determine the as-built
configurations and modifications of certain structures relative to an
amendment approved for this operation in the summer of 1984. Given below
is a comparison of the approved designs and the existing conditions. Other
information is also given where pertinent. A number of photographs taken
the day of my visit are included with this report to help illustrate the
status of these structures and other features. This information is also to
serve as a technical revision to the plan, where appropriate.
Cyanide Pond
The cyanide circuit is not now being used in the milling process due
to some unexpected technical problems encountered in milling the ore.
There are thus no plans to use cyanidation in the near future. In lieu of
using the pond far the disposal of cyanide wastes, the pond may be used in
the future to store fresh water for use in the flotation milling process.
However, the operator does not wish to eliminate the intended function of
the pond from the approved plan because it may ultimately be used again in
conjunction with the cyanidation circuit, approved in the 1984 amendment,
if the technical difficulties are resolved. The operator will, however,
notify the Division if the cyanidization process is to be resumed.
The cyanide pond had only about 2-3 feet of water in it with 9-10 feet
of freeboard at the time of the visit. I was unable to sample any of the
tailings in the cyanide pond (the amount of tailings in the pond was
obviously minimal). The water/tailings have been in the pond for a number
of months and I believe that this would be sufficient residency time of the
water with the solids to reflect a number of chemical characteristics in
the solution. The water was tested on site only for pH and the presence of
free cyanide using the selective ion electrode process. Freshly-mixed
cyanide solutions for use as the calibration standards were made for the
analysis The water had a pH of 8.5 and a free cyanide content determined
to be about 0.27mg/1. It is recognized that the selective ion electrode
measurement technique is probably not as accurate for low levels of free
cyanide as implied, but does provide a framework of magnitude for the
purposes of preliminary data assessment.
With regards to the construction of an overflow from the lined pond to
the lower tailings pond, the operator has reported that a ditch and berm
has been constructed as of September 9 from the northeast side of the lined
pond down to the lower tailings area. According to the operator, the
overflow structure measures approximately 10 feet wide by 4 feet deep and
would route any overflow from the lined pond to the lower area.
1210 Suuth Park Drive, Munument, Colorado 80132 [phone]