| (a) Spoil not required to achieve the approximate original
contour within the area where overburden has been removed shall be
hauled or conveyed to and placed in designated disposal areas within
a permit area, if the disposal areas are authorized for such purposes
in the approved permit application in accordance with this section
and §§12.364-12.366 of this title (relating to Disposal
of Excess Spoil: Valley Fills, Disposal of Excess Spoil: Head-of-Hollow
Fills, and to Disposal of Excess Spoil: Durable Rock Fills). The spoil
shall be placed in a controlled manner to ensure:
(1) that leachate and surface runoff from the fill
will not degrade surface or ground waters or exceed the effluent limitations
referenced in §12.340 of this title (relating to Hydrologic Balance:
Water-Quality Standards and Effluent Limitations);
(2) stability of the fill; and
(3) that the land mass designated as the disposal area
is suitable for reclamation and revegetation compatible with the natural
surroundings.
(b) The fill shall be designed using recognized professional
standards, certified by a qualified professional engineer, and approved
by the Commission.
(c) All vegetative and organic materials shall be removed
from the disposal area and the topsoil shall be removed, segregated,
and stored or replaced under §§12.334-12.338 of this title
(relating to Topsoil: General Requirements, to Topsoil: Removal, to
Topsoil: Storage, to Topsoil: Redistribution, and to Topsoil: Nutrients
and Soil Amendments). If approved by the Commission, organic material
may be used as mulch or may be included in the topsoil to control
erosion, promote growth of vegetation, or increase the moisture retention
of the soil.
(d) Slope protection shall be provided to minimize
surface erosion at the site. Diversion design shall conform with the
requirements of §12.341 of this title (relating to Hydrologic
Balance: Diversions). All disturbed areas, including diversion ditches
that are not riprapped, shall be vegetated upon completion of construction.
(e) The disposal areas shall be located on the most
moderately sloping and naturally stable areas available as approved
by the Commission. If such placement provides additional stability
and prevents mass movement, fill materials suitable for disposal shall
be placed upon or above a natural terrace, bench, or berm.
(f) The spoil shall be hauled or conveyed and placed
in horizontal lifts in a controlled manner, concurrently compacted
as necessary to ensure mass stability and prevent mass movement, covered,
and graded to allow surface and subsurface drainage to be compatible
with the natural surroundings and ensure a long-term static safety
factor of 1.5.
(g) The final configuration of the fill must be suitable
for postmining land uses approved in accordance with §12.399
of this title (relating to Postmining Land Use), except that no depressions
or impoundments shall be allowed on the completed fill.
(h) Terraces may be utilized to control erosion and
enhance stability if approved by the Commission and consistent with §12.385(b)
of this title (relating to Backfilling and Grading: General Grading
Requirements).
(i) Where the slope in the disposal area exceeds 2.8h:1v
(36%), or such lesser slope as may be designated by the Commission
based on local conditions, keyway cuts (excavations to stable bedrock)
or rock toe-buttresses shall be constructed to stabilize the fill.
Where the toe of the spoil rests on a downslope, stability analyses
shall be performed in accordance with §12.153(c) of this title
(relating to Disposal of Excess Spoil) to determine the size of rock
toe-buttresses and key-way cuts.
(j) The fill shall be inspected for stability by a
qualified professional engineer, or other qualified professional specialist
under the direction of the professional engineer, experienced in the
construction of earth and rockfill embankments, at least quarterly
throughout construction and during the following critical construction
periods:
(1) removal of all organic material and topsoil;
(2) placement of underdrainage systems and protective
filter systems;
(3) installation of surface drainage systems;
(4) placement and compaction of fill materials; and
(5) revegetation.
(k) The qualified professional engineer shall provide
to the Commission a certified report, within 2 weeks after each inspection,
that the fill has been constructed as specified in the design approved
by the Commission. The certified report on the drainage system and
protective filters shall include color photographs taken during and
after construction, but before underdrains are covered with excess
spoil. If the underdrain system is constructed in phases, each phase
shall be certified separately. A copy of the report shall be retained
at the minesite.
(l) Coal processing wastes shall not be disposed of
in head-of-hollow or valley fills, and may only be disposed of in
other excess spoil fills, if such waste is:
(1) placed in accordance with §12.371 of this
title (relating to Coal Processing Waste Banks: General Requirements);
(2) demonstrated to be non-toxic and non-acid-forming;
and
(3) demonstrated to be consistent with the design stability
of the fill.
(m) If the disposal area contains springs, natural
or manmade watercourses, or wet-weather seeps, an underdrain system
consisting of durable rock shall be constructed from the wet areas
in a manner that prevents infiltration of the water into the spoil
material. The underdrain system shall be protected by an adequate
filter and shall be designed and constructed using standard geotechnical
engineering methods. Where excess durable rock spoil is placed in
single or multiple lifts such that the underdrain system is constructed
simultaneously with excess spoil placement by the natural segregation
of dumped materials, color photographs shall be taken of the underdrain
as the underdrain system is being formed.
(n) 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 in order to determine the design requirements for
stability of the foundation. Analyses of foundation conditions shall
include the effect of underground mine workings, if any, upon the
stability of the structure.
(o) Excess spoil may be returned to underground mine
workings, but only in accordance with a disposal program approved
by the Commission and MSHA upon the basis of a plan submitted under §12.193
of this title (relating to Underground Development Waste/Return of
Coal Processing Waste to Abandoned Underground Workings).
(p) Excess spoil that is acid-forming or toxic-forming
or combustible shall be adequately covered with non-acid, non-toxic
and noncombustible material, or treated, to control the impact on
surface and ground water in accordance with this chapter (relating
to Coal Mining Regulations), to prevent sustained combustion and to
minimize adverse effects on plant growth and the approved postmining
land use.
(q) The photographs required by this section to accompany
each certified report shall be taken in adequate size and number with
enough terrain or other physical features of the site shown to provide
a relative scale to the photographs and to specifically and clearly
identify the site.
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