PERMFILE53867

• Permit No: M1977004
• IBM Index Class Name: Permit File
• Doc Date: 8/31/1984
• Doc Name: Response to Adequacy
• From: Homestake
• To: DMG
• Media Type: D
• Archive: No

-3-
pond is about 19.75 acres. The resulting average annual evaporation would
therefore be 7.4 acre feet, which is substantially less than one percent
of the 3,640 acre feet annual yield of Indian Creek. The effect on
Marshall and Tomichi Creeks would be, of course, less.
As we have discussed, we do not believe a plan of augumentation is
necessary for the proposed reclamation plan.
The following items were raised by Dr. Jim Pendleton, Review Memorandum of
March 28, 1484, concerning the geotechm cai aspects of the_amendment.
Item: Determination of the term and nature of Homestake's responsibility for
final stabilization of the existing landslide on the northeast wall of the
North Pit.
Response: Call & Nicholas, Inc., consultants to Homestake Mining Company,
completed an analysis of the existing landslide on the northeast wall of the
North Pit at the Pitch Mine. The subsequent report, included in the Amendment
as Supplement Report S-3, concluded that the "final" topography will be
between the present topography and the projected maximum topography, and that
equilibrium would be reached in five years after backfilling or ten years
from the present time, if there was no backfilling. The Division has
observed that the projected rate of adjustment may not be accurate.
uomestake is aware of its responsibility for reclaiming the landslide area
regardless of the time involved {rate of adjustment) in reaching the "final"
equilibrium configuration. Homestake does not plan to grade the slide area
prior to its reaching equilibrium conditions, nor is it anticipated that any
major grading effort would be desirable or appropriate after the equilibrium
conditions are met. In order to accomplish minor regrading to reduce
locally steep slopes and fissures located near the head of the slide area, and
thus to reduce the potential for erosion and increase the stability for
revegetation, adequate surety has been incorporated in the calculations
for Exhibit L. These minor grading activities have been termed "final dressing."
We believe that Homestake and the Division are in agreement that the
landslide will proceed toward equilibrium. It is generally agreed that the
equilibrium configuration will be at an angle conducive to the establishment
of vegetation. The final configuration may vary slightly from that projected
in the amendment application (Drawing 02001-2), while still meeting the
objectives of the approved reclamation plan. If a significant variance
from the projected configuration occurs, adjustments to the approved
plan should be made at the time equilibrium is reached,
Item: The operator should prepare and submit a sampling program including
criteria for determining when final consolidated topographic conditions have
been achieved ("success criteria").
Response: Homestake agrees with the Division that an important consideration
is the criteria used for determinin when final topographic configuration
has been achieved (success criteria . Call & Nicholas, Inc. was again
retained by Homestake for determining these criteria. Their report is
attached. Based on investigations of the slide area and knowledge of the
phenomena of mass movement of soil and rock, Homestake proposes to monitor