2017-02-03_PERMIT FILE - C1980004A ‎(8)‎

• Permit No: C1980004A
• IBM Index Class Name: Permit File
• Doc Date: 2/3/2017
• Section_Exhibit Name: Section 2.05 & 2.06
• Media Type: D
• Archive: Yes

2.05.3
Hydraulic Conductivity specification of 1x10"' cm/sec, the native soils are
proposed to be amended with bentonite. Huddleston -Berry Engineering and
Testing (HBET), or another approved Geotechnical firm will complete a mix
design to establish the percentage of bentonite required to be blended into the
native soils in order to meet the Hydraulic Conductivity specification.
Subsequently, the full suite of testing outlined in Appendix T, Table 1 will be
completed on the blended material to be used for the liner construction. If
bentonite is to be used, it will be obtained off-site and the blended liner will be 12 -
inches thick.
During installation, in order to ensure the soil liner will perform as designed,
construction materials testing will be conducted by qualified engineering
technicians under the direction of a Field Testing Services Manager and/or
Project Engineer. Prior to liner construction, the subgrade will be evaluated to
ensure that it is free of unsuitable materials. In addition, a geotechincal engineer
will observe proofrolling of the subgrade to ensure subgrade stability in
accordance with referenced Solid Waste Guidance Document, as incorporated in
Exhibit 20. Subsequent to proofrolling, but prior to liner placement, a
geotechnical engineer will verify that subgrade is properly scarified. In
accordance with the referenced Solid Waste Guidance Document, materials
testing during liner construction for the sediment pond will be conducted as
summarized in Appendix T, Table 1.
Twelve inches of native soil will be used as a liner cover in order to prevent
cracking of the liner, and damage during sediment cleanout. The soil cover will
be compacted until it attains at least 90% of the maximum dry density attained in
a laboratory compaction test in accordance with ASTM D698. Compaction
testing will be taken at a frequency and location of not less than one per every
other layer, at random locations across the ponds.
(ii)(C) Operations and maintenance requirements forthe pond. The sediment pond
must be dewatered if it contains water above the maximum sediment level.
Dewatering events should occur within 48 hours after the storm event or
mine discharge which caused the water accumulation. Sediment must be
removed from the sediment pond no later than when the sediment is 60% of
the ponds maximum sediment level.
PR -02 2.05-20- 10/12