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 C O L O R A D O
Denver, Colorado 80203 n t v[ s t. o N o f
Phone: [phone] RECLAMATION
FAX: [phone] MINING
-&-
° SAFETY
DATE: April 18, 2008 Bill Ritter,Jr.
Governor
TO: Wallace H. Erickson, DRMS Harris D. Sherman
Executive Director
FROM: David Bird, DRMS Ronald W. Cattany
Division Director
• Natural Resource Trustee
RE: Geochemical Adequacy Review, AM-03,
San Luis Project, Permit No. M-1988-112.
1) Fate of Manganese (Mn) and Fluoride (F). The operator has done a commendable job of attempting to
predict the fate of Mn and F after land application at the Salazar Ranch, through the combination of
laboratory batch tests and contaminant transport modeling. However, I would like to see the tests
expanded. For example, their tests have only assessed the attenuation within the topmost 2 feet of soil,
and only with one cycle of application. I recommend that they conduct more comprehensive testing that
includes the geologic materials throughout the unsaturated zone. I also suggest that they consider lateral
variation in soil chemical characteristics, perhaps testing several locations along the conceived ground
water flow path. To accomplish this, I recommend a Sequential Batch Test (ASTM method D 4793-88)
using site specific geologic materials and West Pit ground water as they did in the initial round of tests.
The well data provided in Table G.3-1 indicates that the depth to water in the SLM monitoring wells
ranges from 14 to 135 ft bgs. The SBTs would allow simulation of infiltration water moving from one
soil type to another, either vertically or horizontally. I am particularly interested in the attenuation and
leaching behavior of specific geologic materials after repeated applications and loading using the West Pit
ground water. This would help verify the claim of unlimited attenuation capacity in the soil. Because of
the high profile of this case and the consequences of incomplete or erroneous evaluation, we must demand
the most defensible analyses possible, and this testing procedure will be a crucial step towards that goal.
Operator has not evaluated the possibility of remobilization of constituents (e.g. F, Mn) from the aquifer
geologic materials due to changes in pH or redox conditions. I recommend additional laboratory testing,
which could be performed using the same loaded materials from the previous tests, to evaluate the
capability of the material to retain the constituents during chemical stresses imposed by changes in pH
and redox conditions.
2) Parameters for ground water flow model. Designation of the eastern model boundary as a no-flow
boundary is curious, because mountain ranges are generally considered to be recharge areas. Please
provide the rationale for designating the eastern boundary as a no-flow boundary. Additionally, general
head boundaries can be problematic. I recommend running some model simulations to assess the
sensitivity of the model to the different types of boundaries.
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