1990-01-09_REVISION - M1988112 ‎(6)‎

• Permit No: M1988112
• IBM Index Class Name: Revision
• Doc Date: 1/9/1990
• Doc Name: FAX COVER
• From: STEFFEN ROBERTSON & KIRSTEN
• To: MLRD
• Type & Sequence: AM1
• Media Type: D
• Archive: No

90 03109 18:?6 ~ S 303 965 9947 SRK DENV~ 03
BATTLE MOUNTAIN RESOURCES, SAN LUIS PROJECT
CMLRD ADEQUACY LETTER RESPONSES
Page 17 of 28
26. Please provide a sliding wedge stability analysts for the main
embankment at Phase 2, Raise I and Phase 2, Raise 2.
RESPONSE: The sliding wedge stability analysis for the main embankment is
provided on the revised Figure D.6-9, 511ding Wedge Stability
Summary.
27. Please revise the stability analysis summary in Figure 0.6-12 to
include the VLDPE instead of the material type 1 as foundation
material.
RESPONSE: Figure D.6-12 has been revised to include the VLDPE instead of
Material Type 1 as foundation material. The revised figure is
included here.
28. Please provide a stability analysis of Waste Rock Disposal Area D,
similar to those provided for the other waste rock facilities in the
approved application.
RESPONSE: The stability analysis for Waste Rock Disposal Area D is provided
in Figure D.3-2. This analysis did not include an analysis of the
single bench static and pseudostatic factors of safety. A revised
Figure D.3-2 1s provided with this submittal.
29. Piease describe what methods wiil be used to validate the assumption
that unsaturated conditions will be maintained within the embankment
fill throughout the life of the facility. Pietometers should be
placed within the embankment, and within the tails adjacent to the
embankment inslope to verify the design assumptions.
RESPONSE: A series of pneumatic plezometers will be placed beneath the
embankment, at the upstream toe of the embankment and within the
beach sands deposited on the upstream slope of the embankment.
30. The mode) assumes 5OX of the tailings disposal area is under
deposition at any paint in time and thus 50X of the area wit) be
evaporating. How many days wi 11 an area of tai 1 logs be dry and
sub,~ect to wind erosion? What would be the maximum extent (acres)
of area with moisture conditions conducive to wind erosion and
resultant dust generation? What measures, aside from residual
moisture, will be used for dust control?
RESPONSE: Once the area of tailings approaches desiccation and begins to dry
at the surface, this is an indication that the thin layer deposition
concept is working properly and that the area is ready for the next
thin layer to be deposited. Dust generation at the facility will be
controlled through the active management of the thin layer deposition
techniques. As an area dries out, the spigots will be reopened and
more slurry deposited, preventing dust generation.