PERMFILE44671

• Permit No: C1982055A
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Doc Name: page 454 - 539
• Section_Exhibit Name: SECTION 2.05 OPERATION PLAN PART 2
• Media Type: D
• Archive: Yes

will be utilized to accomplish adequate compaction. Aa with
both previous designs, overburden material will be stripped
in advance of the refuse pile as it expands and replaced over
the top of the final graded elopes. A minimum of 3.5 feet of
overburden material will be placed over regraded and
compacted refuse. Then a minimum of 6 inches of topsoil
material will be replaced and the site will be revegetated
utilizing the seed mix and methods described is the reclama-
tion plan under Section 2.05.4.
4. Stability: Based upon the stability analysis conducted for
each oP the previous refuse disposal area designs, the
stability safety factor for the current refuse embanlaneat
design will be in excess of 2.5. Zn the initial design
submitted by the previous operator in 1982, physical
parameters affecting stability ware estimated based upon data
from seven similar waste sites obtained from the Hureau of
!linen Report of Investigation 7964 titled Physical Proverty
• Data oa Coal Waste Embanloneat Materials. These factors were
as follows:
1. Placement density 89.5 lbe/cu. ft.
2. Internal angle o! friction 33.4°
3. Cohesion 3.1 psi
Utilizing as overall average elope of 3.5 horizontal to 1
vertical and a maximum pile height of 145 feet, the factor of
safety for the initial design was determined utilizing the
Bureau of Mines Report of Investigation 8564 titled Factor of
Safety Charts !or Eatimatina the Stability of Saturated and
Unsaturated Tailinaa Pond Embanlasents. The resultant factor
safety was 3.2. A sensitivity analysis was performed
utilizing the above described references and by varying
cohesions down to 0 psi and internal angles of friction down
to 24.b°. The sensitivity analysis indicated that the lowest
possible factor of safety for the initial design would be
1.76.
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Revised 1/88