405 KAR 3:180. Coal waste dams.
TO: KRS 350.151
AUTHORITY: KRS 350.151
FUNCTION, AND CONFORMITY: KRS 350.151 requires the Environmental and Public
Protection Cabinet to adopt rules and administrative regulations for the surface
effects of underground coal mining. This administrative regulation sets forth
requirements for the design, construction, maintenance and reclamation of coal
1. General. No waste material shall be used in existing or new dams without the
approval of the cabinet. The permittee shall design, locate, construct,
operate, maintain, modify, and abandon or remove all dams (used either
temporarily or permanently) constructed of waste materials, in accordance with
the requirements of this administrative regulation.
2. Construction of Dams. (1) Waste shall not be used in the construction of
dams unless demonstrated through appropriate engineering analysis, to have no
adverse effect on stability.
Plans for dams subject to this section, and also including those dams that do
not meet the size or other criteria of 30 CFR 77.216(a) shall be approved by
the cabinet before construction and shall contain the minimum plan requirements
established by the Mine Safety and Health Administration pursuant to 30 CFR
Construction requirements are as provided in this subsection:
Design shall be based on the flood from the probable maximum precipitation
event unless the permittee shows that the failure of the impounding structure
would not cause loss of life or severely damage property or the environment, in
which case, depending on site conditions, a design based on a precipitation
event of no less than 100-year frequency may be approved by the cabinet.
The design freeboard distance between the lowest point on the embankment crest
and the maximum water elevation shall be at least three (3) feet to avoid
overtopping by wind and wave action.
Dams shall have minimum safety factors as provided in the following table:
Minimum Safety Factor
pool with steady seepage saturation
seepage from spillway or decant crest
(cases II and III with seismic loading)
The dam, foundation, and abutments shall be stable under all conditions of
construction and operation of the impoundment. Sufficient foundation
investigations and laboratory testing shall be performed to determine the
factors of safety of the dam for all loading conditions in this administrative
regulation and for all increments of construction.
Seepage through the dam, foundation, and abutments shall be controlled to
prevent excessive uplift pressures, internal erosion, sloughing, removal of
material by solution, or erosion of material by loss into cracks, joints, and
cavities. This may require the use of impervious blankets, pervious drainage
zones or blankets, toe drains, relief wells, or dental concreting of jointed
rock surface in contact with embankment materials.
Allowances shall be made for settlement of dams and foundations so that the
required freeboard will be maintained.
Impoundments created by dams of waste materials shall be subject to a minimum
drawdown criteria that allows the facility to be evacuated within ten (10) days
by spillways or decants of ninety (90) percent of the volume of water stored
during the design precipitation event.
During construction of dams subject to this administrative regulation the
structures shall be periodically inspected by a registered professional
engineer to ensure construction according to the approved design. On completion
of construction, the structure shall be certified by a registered professional
engineer experienced in the field of dam construction as having been
constructed in accordance with accepted professional practice and the approved
A permanent identification marker, at least six (6) feet high that shows the
dam number assigned pursuant to 30 CFR 77.216-1 and the name of the person operating
or controlling the dam, shall be located on or immediately adjacent to each dam
within thirty (30) days of certification of design pursuant to this
All dams, including those not meeting the size or other criteria of 30 CFR
77.216-1, shall be routinely inspected by a registered professional engineer,
or someone under the supervision of a registered professional engineer, in
accordance with Mine Safety and Health Administration regulations pursuant to
30 CFR 77.216-3.
All dams shall be routinely maintained. Vegetative growth shall be cut where
necessary to facilitate inspection and repairs. Ditches and spillways shall be
cleaned. Any combustible materials present on the surface, other than that used
for surface stability such as mulch or dry vegetation, shall be removed and any
other appropriate maintenance procedures followed.
All dams subject to this administrative regulation shall be certified annually
as having been constructed and modified in accordance with current prudent
engineering practices to minimize the possibility of failures. Any changes in
the geometry of the impounding structure shall be highlighted and included in
the annual certification report. These certifications shall include a report on
existing and required monitoring procedures and instrumentation, the average
and maximum depths and elevations of any impounded waters over the past year,
existing storage capacity of impounding structures, any fires occurring in the
material over the past year and any other aspects of the structures affecting
Any enlargements, reductions in size, reconstruction or other modification of
the dams shall be approved by the cabinet before construction begins.
All dams shall be removed and the disturbed areas regraded, revegetated, and
stabilized before the release of bond unless the cabinet approves retention of
such dams as being compatible with an approved postmining land use.
waste dams (except those classified as Class (A) pursuant to 405 KAR 3:020,
Section 5(2)(d)) constructed pursuant to this administrative regulation shall
be approved by the cabinet, designed, constructed and maintained according to
the provisions of KRS 151.250 and administrative regulations adopted pursuant
thereto. (4 Ky.R. 422; eff. 5-3-78; Am. 526; 5 Ky.R. 232; eff. 8-23-78; TAm