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Table 1.3 Natural and Artificial Containment Features for Mining
Units
| Waste Group |
Waste Management Unit |
Geologic Setting |
Liner(s) Hydr. Cond. Values
(Units: cm/sec) |
Leachate Collection and
Removal System |
| A |
Waste Pile |
per §2531(b)(1) of Title 23, OR
single clay liner1 < 1x10-7 |
|
required |
| |
Surface Impoundment or Tailings
Pond |
not applicable |
double liner, both < 1x10-7
outer clay; Inner: clay or synthetic |
required(2) |
| B |
Waste Pile |
per §20250(b)(1) OR single clay
liner |
< 1x10-6(1) |
required |
| |
Surface Impoundment or Tailings
Pond |
not applicable |
double liner, both < 1x10-6//
outer : clay or natural permeability(3); inner: clay or
synthetic
OR
single replaceable clay liner(4) |
required(2) |
| C |
Waste Pile, Surface Impoundment, Tailings Pond |
not applicable |
not applicable |
not applicable |
(1) Synthetic liner may be used for short-term
containment [see §22490(f)(1)].
(2) Liner and leachate collection and removal system for tailings pond must
be able to withstand the ultimate weight of wastes.
(3) Permability of < 1x10-6 cm/sec or natural geologic materials
may replace outer liner of double liner system.
(4) Single clay liner <(1x10-6 cm/sec) for surface impoundment,
to be removed before last 25 percent (minimum 1 foot thickness) of liner is
penetrated by fluid, including waste and leachate.
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