Current through Vol. 42, No. 1, September 16, 2024
(a) The Department may approve the disposal
of excess spoil through placement on preexisting benches, provided that all the
standards set forth in Sections
460:20-43-24(a),(b)(1),
and
460:20-43-24(d)
-
(I) and the requirements of this Section are
met.
(b) Excess spoil
shall be placed only on the solid portion of the preexisting bench.
(c) The fill shall be designed and
constructed using current prudent engineering practices. The design will be
certified by a registered professional engineer. The spoil shall be placed on
the solid portion of the bench in a controlled manner and concurrently
compacted as necessary to attain a long-term static safety factor of 1.3 for
all portions of the fill. Any spoil deposited on any fill of the bench will be
treated as excess spoil fill under 460:20:43-24.
(d) The preexisting bench shall be backfilled
and graded to:
(1) Achieve the most moderate
slope possible which does not exceed the angle of repose, and
(2) Eliminate the highwall to the maximum
extent technically practical.
(e) Disposal of excess spoil from an upper
actively mined bench to a lower preexisting bench by means of gravity transport
may be approved by the Department provided that:
(1) The gravity transport courses are
determined on a site-specific basis by the operator as part of the permit
application and approved by the Department to minimize hazards to health and
safety and to ensure that damage will be minimized between the benches, outside
the set course, and downslope of the lower bench should excess spoil
accidentally move;
(2) All gravity
transported excess spoil, including that excess spoil immediately below the
gravity transport courses and any preexisting spoil that is disturbed, is
rehandled and placed in horizontal lifts in a controlled manner, concurrently
compacted as necessary to ensure mass stability and to prevent mass movement,
and graded to allow surface and subsurface drainage to be compatible with the
natural surroundings and to ensure a minimum long-term static safety factor of
1.3. Excess spoil on the bench prior to the current mining operation that is
not disturbed need not be rehandled except where necessary to ensure stability
of the fill;
(3) A safety bean is
constructed on the solid portion of the lower bench prior to gravity transport
of the excess spoil. Where there is insufficient material on the lower bench to
construct a safety berm, only that amount of excess spoil necessary for the
construction of the berm may be gravity transported to the lower bench prior to
construction of the berm.
(4)
Excess spoil shall not be allowed on the downslope below the upper bench except
on designated gravity transport courses properly prepared according to Section
460:20-43-7.
Upon completion of the fill, no excess spoil shall be allowed to remain on the
designated gravity transport course between the two benches and each transport
course shall be reclaimed in accordance with the requirements of this
Subchapter.
Amended at 16 Ok Reg
3526, eff 9-13-99
