2008-04-25_REVISION - M1988112

• Permit No: M1988112
• IBM Index Class Name: REVISION
• Doc Date: 4/25/2008
• Doc Name: Preliminary Adequacy Issues
• From: DRMS
• To: Battle Mountain Resources, Inc.
• Type & Sequence: AM3
• Email Name: WHE
• 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: April 15, 2008
TO: Wally Erickson
COLORADO
D I V I S 1 0 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: Water Management and Quality Adequacy Issues, Battle Mountain Resources, Inc.,
San Luis Project, Permit Amendment AM-03, Permit No. M-1988-112
The Division of Reclamation, Mining, and Safety (DBMS) engineering staff have reviewed the water
management and quality aspects of the above referenced amendment application, and lists in this memo issues
that must be addressed by the Applicant. The engineering aspects of the application are also under review and
will be the subject of a separate memorandum.
It is stated in that Exhibit G.1 that the pipeline from the west pit to the tailing disposal area will be maintained as
a contingency. What is the water balance for this contingency (rate of flow from west pit versus tailing pond
capacity)?
Appendix E: There is a mathematical error in the fluoride uptake calculation provided. 53.12 pounds fluoride
per year will be removed by the crop, not 531.09 pounds as stated in the appendix. However, alfalfa removed in
the crop was conservatively not considered in the ground water model presented in Appendix F, so this error
does not affect the model results.
Appendix E: Using a plant tissue fluoride concentration factor of three times the concentration in the irrigation
water is conservative relative to alfalfa uptake of fluoride calculations, but not relative to fluoride toxicity to
alfalfa. For toxicity, a conservative tissue value would be six times the concentration in the water, yielding a
safe irrigation water concentration of 100 ppm/6 = 18.3 ppm, showing that although the method was flawed, the
conclusion is the same. The west pit water used for irrigation will not be toxic for the crop.
Appendix E: Again, using a plant tissue fluoride concentration factor of three times the concentration in the
irrigation water is not conservative relative to fluoride toxicity to animals. Using a conservative value of six and
the dietary safe level of 30 ppm fluoride in feed for deer, elk, and dairy cattle the calculation of maximum
allowable fluoride in irrigation water is 30 ppm/6 = 5 ppm. This is just slightly above the west pit water fluoride
concentrations, and since the information contained in Appendix E is for clover, not alfalfa, poses an
unacceptable level of risk that the alfalfa will be toxic to wild ungulates and dairy cattle. DBMS recognizes that
this risk is based on the conservative assumption that 100 percent of the animal's diet will be plants with 30 ppm
fluoride, but even so, the DBMS will require further evaluation of this issue before recommending approval of
the amendment application. It is DRMS's understanding that alfalfa is being irrigated using high fluoride water
in New Mexico, and is likely to be occurring elsewhere. Sampling and analysis of such alfalfa would provide
the information necessary to resolve this issue.
The proposal to construct water storage ponds in the west pit area states that the ponds will be lined with
geomembrane. Issues related to the pond and liner designs will be addressed in the forthcoming memo on the
engineering aspects of the amendment application. For water quality aspects of the proposed ponds, the
Office of Office of
Mined Land Reclamation Denver Grand )unction Durango Active and Inactive Mines