ENFORCE25154

• Permit No: C1982055
• IBM Index Class Name: Enforcement
• Doc Name: COAL PROCESSING WASTE AND NON-COAL PROCESSING WASTE
• Violation No.: CV1993084
• Media Type: D
• Archive: No

will be utilized to accomplish adequate compaction. As with
~,, both previous designs, overburden material will be stripped
i
in advance of the relusa pile as it expands and replaced over
the top of the final graded elopes. A minimum o! 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 play under Section 2.05.4.
4. Stability: Haled upon the stability analysis conducted for
each of the previous refuse disposal area designs, the
stability safety !actor for the current refuse embanlonent
design will be is excess of 2.5. In the initial design
submitted by the previous operator in 1982, physical
parameters affecting stability ware estimated based upon data
from seven similar xaete sites obtained from the Bureau of
Pines Report of Investigation 7964 titled Phvaieal Property
Data on Coal Waste Emban3anent !(ateriale. These factors were
`~~}' as follows
~,,:
i. Placement density 89.5 lbs/cu. it.
2. Internal angle of 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 o! 145 test, the factor of
safety for the initial design was determined utilizing the
Bureau of !lines Report of Investigation 8564 titled Factor of
Safety Charts for Estimating the Stabilitw of Saturated and
Unsaturated Tailings Pond Embanloneats. The resultant factor
ealety was 3.2. A sensitivity analysis was performed
utilizing the above described reierenees and by varying
coheslons down to 0 psi and internal eagles of friction down
to 24.b°. The sensitivity analysis indicated that the lowest
possible factor of safety for the initisl design would be
1.75.
r'~,
`,..,.
489
Revised 1/88