Sec. 34.
(a) All
excess spoil material resulting from mining and reclamation activities must be
placed as follows:
(1) Spoil shall be
transported and placed in a controlled manner in a position for concurrent
compaction, and to:
(A) assure
stability;
(B) prevent mass
movement; and
(C) ensure a long
term static safety factor of one and five-tenths (1.5).
(2) The areas of disposal shall be within the
bonded permit areas, and all organic matter shall be removed immediately before
spoil placement.
(3) Sufficient
surface and internal drainage systems and diversion ditches shall be used to
prevent spoil erosion and movement.
(4) The disposal area shall not contain
springs, natural water courses, or wet weather seeps unless lateral drains are
constructed from the wet areas to the main underdrains to prevent the
infiltration of the water into the spoil pile.
(5) If placed on a slope, the spoil shall be
placed upon the most moderate slope available that the director determines will
ensure compliance with IC 14-34. If possible, the spoil shall be placed upon or
above a natural terrace, bench, or berm if this placement will provide
additional stability and prevent mass movement.
(6) Where the toe of the spoil rests on a
downslope, a rock toe buttress of sufficient size to prevent mass movement
shall be constructed.
(7) The final
configuration shall be compatible with the natural drainage pattern and
surroundings and suitable for intended uses. Terraces may be constructed on the
outslope if required for stability, control of erosion, conservation of soil
moisture, or facilitation of the approved postmining land use. The grade of the
outslope between terrace benches shall not be steeper than fifty percent (50%),
2h:1v.
(8) The spoil disposal area
shall be designed and inspected during construction under the supervision of,
and certified after construction by, a qualified registered professional
engineer.
(9) The foundation and
abutments of the fill shall be stable under all conditions of construction and
operation. Sufficient foundation investigation and laboratory testing of
foundation materials shall be performed to determine the design requirements
for stability of the foundation. Analyses of foundation conditions shall
include the effect of underground mine workings upon the stability of the
structure.
(10) Spoil shall be
placed in horizontal lifts not exceeding four (4) feet thick, except where the
director approves a greater thickness based upon:
(A) a certification by a qualified registered
professional engineer that the design ensures the stability of the fill;
and
(B) a demonstration by the
permittee that all other requirements of this section are satisfied.
(11) No permanent impoundments
shall be allowed on the completed fill. Small depressions may be allowed by the
director if they are needed to retain moisture, minimize erosion, create and
enhance wildlife habitat, or assist revegetation, and if they are not
incompatible with stability of the fill.
(b) All box cut spoil that is demonstrated to
be excess spoil under section 50 of this rule must conform to the following:
(1) Topsoil shall be removed from the area
upon which the box cut spoil will be placed.
(2) The topsoil shall be handled consistently
with the topsoil storage and replacement requirements of this
article.
(3) If placed on a slope,
the box cut spoil shall be placed upon the most moderate slope available which
the director determines will ensure compliance with IC 14-34 and which will
prevent mass movement.
(4) The
final graded slope of box cut spoil areas shall not exceed thirty-three and
one-third percent (33a%) or any lesser slope approved by the director based
upon a consideration of soil, climate, land use, or other characteristics of
the surrounding area.
(5) The final
surface configuration shall be compatible with the natural drainage pattern and
surroundings, and the reclamation of the box cut spoil shall achieve an
ecologically sound land use compatible with existing land use policies and
plans.
(c) Excess spoil
areas, including box cut spoil approved as excess as outlined under subsection
(b), shall be inspected by a qualified registered professional engineer or
another qualified specialist under the direction of a qualified registered
professional engineer, who shall periodically inspect the fill during
construction. The professional engineer or specialist must be experienced in
the construction of earth and rock fills.
(d) The inspections required under subsection
(c) must be made at least quarterly throughout construction and during critical
construction periods. Critical construction periods include the following:
(1) Foundation preparation including the
removal of organic material and topsoil.
(2) The placement of underdrains and
protective filter systems.
(3) The
installation of final surface drainage systems.
(4) The placement and compaction of fill
materials.
(5) The establishment of
final graded and revegetated fill.
(e) The registered professional engineer
shall provide a report to the director promptly after each inspection performed
under subsection (c) that certifies that any fill has been constructed and
maintained as designed and under the approved reclamation plan and this
article. The report shall identify any appearance of instability, structural
weakness, or other hazardous condition. A report on any drainage system or
protective filter shall include color photographs taken during and after
construction (but before an underdrain is covered with excess spoil). If an
underdrain system is constructed in phases, each phase shall be certified
separately.
(f) A copy of each
inspection report shall be retained at or near the mine site.
