PERMFILE46723

• Permit No: M1988112
• IBM Index Class Name: Permit File
• Doc Date: 11/8/1988
• Section_Exhibit Name: APPENDIX Q ADEQUACY REVIEW QUESTIONS AND RESPONSES
• Media Type: D
• Archive: No

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determination of the need for the slurry wall, the final design of
such a structure if necessary and a proposed implementation schedule
as a
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.
The preliminary slurry wall designs were presented in a letter dated
March 2, 1989 from Steffen Robertson and Kirsten (SRK) to the Mined
Land Reclamation Division. The slurry wall will be keyed into the
Santa Fe Conglomerate on the bottom and east and west sides of the
south wall. The extent of the alluvium in the south wall of the West
Pit was determined using existing drilling data. As shown on Figure
1, the extent of the alluvium is believed to be limited to the area
of the pit closest to the creek. As the pit wall limit moves away
from the creek and upward in elevation the alluvium is not present
and the uppermost unit is the Santa Fe Conglomerate. The slurry wall
is designed to intercept all potential flowpaths through the alluvium
by keying the bottom and both ends of the wall into the Santa Fe
Conglomerate. As shown on Figure 2, the alluvium/Santa Fe Ccontact
and the slurry wall are deepest in areas closest to the creek. As
the pit wall limit moves away from the creek and the alluviumjSanta
Fe contact moves closer to the surface, the slurry wall will become
shallower. As designed, the slurry wall will extend to the point
where the alluvium is no longer present and key into the near surface
' Santa Fe Conglomerate.
Exhibit E, Section E.3.1.2 revised 4/20/89.
i 2. The anticipated )ocation of the buttress should be shown on the mine
plan and reclamation plan maps.
Response: Since the buttress is related to long-term stability and will not
be placed until final reclamation, the buttress locati~>n has been
added to Figure F-2. A separate map showing the buttress location
' on Figure C-4 is included with this submittal.
Figure F-2 revised 3/10/89.
3. In order to provide fora useful post-mining configuration, as well
as to provide fora convenient waste disposal area, the 'ower slope
of the buttress should be established at 18°, rather than the
proposed 38°. This configuration would minimize erosion potential,
maximize revegefation potential, and provide fora convenient waste
disposal area.
Response: Battle Mountain Resources will agree to placing the lower slope of
the rock toe buttress at 3H:1V rather than the angle of repose. The
report on the buttress entitled "Geotechnical Evaluation for the
' South Wall -West Pit, San Luis Project" will be revised tc show this
change. Four copies of revised Figure F-2 are included which show
reclamation contours for the lower portion of the buttress at 3H:1V.
' Exhibit E, Section E.3.1.2 revised 4/20/89.
' 4. The buttress should be topsoiled with at least 18 inches of topsoil