| (a) The final graded slopes shall not exceed in grade either
the approximate premining slopes, or any lesser slopes approved by the Commission
based on consideration of soil, climate, or other characteristics of the surrounding
area. Postmining final graded slopes need not be uniform but shall approximate
the general nature of the premining topography. The person who conduct surface
mining activities shall, at a minimum:
(1) retain all overburden and spoil on the solid portion of
existing or new benches; and
(2) backfill and grade to the most moderate slope possible
to eliminate the highwall which does not exceed either the angle of repose
or such lesser slope as is necessary to achieve a minimum static safety factor
of 1.3. In all cases the highwall shall be eliminated.
(b) On approval by the Commission in order to conserve soil
moisture, ensure stability, and control erosion on final graded slopes, cut-and-fill
terraces may be allowed, if the terraces are compatible with the approved
postmining land use and are appropriate substitutes for construction of lower
grades on the reclaimed lands. The terraces shall meet the following requirements:
(1) the width of the individual terrace bench shall not exceed
20 feet, unless specifically approved by the Commission as necessary for stability,
erosion control, or roads included in the approved postmining land-use plan;
(2) the vertical distance between terraces shall be as specified
by the Commission, to prevent excessive erosion and to provide long-term stability;
(3) the slope of the terrace outslope shall not exceed 2h:1v
(50%). In no case may highwalls be left as part of terraces; and
(4) culverts and underground rock drains shall be used on the
terrace only when approved by the Commission.
(c) Small depressions may be constructed, if they:
(1) are approved by the Commission to minimize erosion, conserve
soil moisture, or promote vegetation;
(2) do not restrict normal access; and
(3) are not inappropriate substitutes for lower grades on the
reclaimed lands.
(d) All final grading, preparation of overburden before replacement
of topsoil, and placement of topsoil, shall be done along the contour to minimize
subsequent erosion and instability. If such grading, preparation, or placement
along the contour is hazardous to equipment operators, then grading, preparation,
or placement in a direction other than generally parallel to the contour may
be used. In all cases, grading, preparation, or placement shall be conducted
in a manner which minimizes erosion and provides a surface for replacement
of topsoil which will minimize slippage.
(e) Backfilling and grading of previously mined areas shall
be subject to the following requirements:
(1) remining operations on previously mined areas that contain
a preexisting highwall shall comply with the requirements of §12.384
of this title (relating to Backfilling and Grading: General Requirements),
this section, and §§12.386-12.388 of this title (relating to Backfilling
and Grading: Covering Coal and Acid- and Toxic-Forming Materials, to Backfilling
and Grading: Thin Overburden, and to Backfilling and Grading: Thick Overburden),
except as provided in this subsection; and
(2) the requirements of §12.384(b)(1) requiring the elimination
of highwalls shall not apply to remining operations where the volume of all
reasonably available spoil is demonstrated in writing to the Commission to
be insufficient to completely backfill the reaffected or enlarged highwall.
The highwall shall be eliminated to the maximum extent technically practical
in accordance with the following criteria:
(A) all spoil generated by the remining operation and any other
reasonably available spoil shall be used to backfill the area. Reasonably
available spoil in the immediate vicinity of the remining operation shall
be included within the permit area;
(B) the backfill shall be graded to a slope which is compatible
with the approved postmining land use and which provides adequate drainage
and long-term stability;
(C) any highwall remnant shall be stable and not pose a hazard
to the public health and safety or to the environment. The operator shall
demonstrate, to the satisfaction of the Commission, that the highwall remnant
is stable; and
(D) spoil placed on the outslope during previous mining operations
shall not be disturbed if such disturbances will cause instability of the
remaining spoil or otherwise increase the hazard to the public health and
safety or to the environment.
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| Source Note: The provisions of this §12.385 adopted to be effective April 7, 1997, 22 TexReg 3093; amended to be effective November 4, 1997, 22 TexReg 10640; amended to be effective June 12, 2001, 26 TexReg 4090 |
