405 KAR 30:390. Backfilling and grading.
RELATES TO: KRS 350.600
STATUTORY AUTHORITY: KRS 151.125,
224.033, 350.028, 350.050, 350.600
NECESSITY, FUNCTION, AND CONFORMITY: KRS
350.600 requires the Environmental and Public Protection Cabinet to develop administrative
regulations for oil shale operations to minimize and prevent their adverse
effects on the citizens and the environment of the Commonwealth. This
administrative regulation sets forth requirements relating to the backfilling
and grading of areas affected by oil shale operations.
Section 1. Postmining final graded slopes
need not be uniform nor does the mined area have to be backfilled to achieve
the approximate original contour of the land surface.
Section 2. Spoil, spent shale and other
wastes may be disposed of in the mined area provided it is demonstrated to the
satisfaction of the cabinet by hydrological means and chemical and physical
analyses that these waste materials are suitable for use as fill material and
that use of these materials will not adversely affect water quality, water
flow, and vegetation; will not present hazards for public health and safety;
and will not cause instability in the backfilled area.
Section 3. Covering and Stabilizing. (1)
Any acid-forming or toxic-forming materials, combustible materials, or any
other mining waste materials that are exposed, used, or produced during mining
shall be covered with a minimum of four (4) feet of nontoxic and nonacid forming
material; or, if necessary, treated in order to prevent water pollution and
sustained combustion, and to minimize adverse effects on plant growth and land
uses. These four (4) feet of nontoxic, nonacid forming material do not include
the topsoil or topsoil substitute material required in 405 KAR 30:290 relating
to topsoil and 405 KAR 30:280 covering prime farmland. Acid-forming or
toxic-forming material shall not be buried or stored in proximity to a drainage
course so as to pose a threat of water pollution or otherwise adversely affect
the hydrologic balance.
(2) Backfilled materials shall be
selectively placed and compacted as necessary to prevent leaching of
acid-forming and toxic-forming materials into surface or subsurface waters and
wherever necessary to ensure the stability of the backfilled materials. The
method of compacting backfill material and the design specifications shall be approved
by the cabinet before the acid-forming or toxic-forming materials are covered.
(3) Where highwalls are created during
mining which contain various geologic zones with substantially different
weathering rate, the permittee shall, at a minimum, backfill all zones which
are overlain by a formation with a much slower weathering rate.
(4) All backfilling shall be placed and
compacted to achieve a minimum static safety factor of one and three-tenths
(1.3) or higher if deemed necessary by the cabinet based on specific site conditions.
(5) Spent shale shall be disposed of in
mined areas in accordance with the requirements of 405 KAR 30:370, Sections
1(1) and 2 of this administrative regulation.
Section 4. (1) Where deemed necessary by
the cabinet impervious liner(s) will be required in backfill areas to protect
water quality, water flow, water quantity, and vegetation, and to prevent
hazards to public health and safety.
(2) The cabinet shall approve the type
and order in which all materials are backfilled.
Section 5. Grading Along the Contour. All
final grading, preparation of overburden before replacement of topsoil or
topsoil substitute, and placement of topsoil, in accordance with the provisions
of 405 KAR 30:290, shall be conducted in a manner which minimizes erosion and
provides a surface for replacement of topsoil which will minimize slippage.
Section 6. Regrading or Stabilizing Rills
and Gullies. When rills or gullies deeper than nine (9) inches form in areas
that have been regraded and the topsoil or topsoil substitute material replaced
but vegetation has not yet been established, the permittee shall fill, grade,
or otherwise stabilize the rills and gullies and reseed or replant the areas in
accordance with 405 KAR 30:400 with regard to revegetation. The cabinet shall
specify that rills or gullies of lesser size be stabilized if the rills or
gullies will be disruptive to the approved postmining land use or may result in
additional erosion and sedimentation.
Section 7. Small Depressions. If approved
by the cabinet, small depressions may be constructed to minimize erosion,
conserve soil moisture, or promote revegetation. The depressions shall be
compatible with the approved postmining land use and shall not be inappropriate
substitutes for construction of lower grades on the reclaimed lands. Depressions
approved under this section shall have a holding capacity of less than one (1)
cubic yard of water or, if it is necessary that they be larger, shall not
restrict normal access throughout the area or constitute a hazard.
Section 8. Permanent Impoundments. If
approved in the postmining land use plan, permanent impoundments may be
retained on mined and reclaimed areas. No impoundments shall be constructed on
top of areas in which mining and processing waste materials or spent shale are
deposited. Impoundments shall not be used to meet the requirements of Section 4
of this administrative regulation with regard to covering of acid-forming and
toxic-forming materials, spent shale or other waste materials. (8 Ky.R. 133;
Am. 489; eff. 3-1-82; 9 Ky.R. 964; eff. 10-5-83; TAm eff. 8-9-2007.)