Section
1. Diversions and Conveyance of Overland Flow and Shallow
Groundwater Flow, and Ephemeral Streams. Overland flow, including flow through
litter, and shallow
groundwater flow from undisturbed areas, and flow in
ephemeral streams, may be diverted away from
disturbed areas by means of
temporary or permanent diversions, if required or approved by the
cabinet as
necessary to minimize erosion, to reduce the volume of water to be treated, and
to prevent or remove water from contact with acid-forming or toxic-forming
materials. The following requirements shall be met for all diversions and for
all collection drains that are used to transport water into water treatment
facilities and for all diversions of overland and shallow groundwater flow and
ephemeral streams:
(1) Temporary diversions
shall be constructed to pass safely the peak run-off from a precipitation event
with a two (2) year recurrence interval, or a larger event as specified by the
cabinet.
(2) To protect fills and
property and to avoid danger to public health and safety, permanent diversions
shall be constructed to pass safely the peak run-off from a precipitation event
with a ten (10) year recurrence interval, or a larger event as specified by the
cabinet. Permanent diversions shall be constructed with gently sloping banks
that are stabilized by vegetation. Asphalt, concrete, or other similar linings
shall be used only when approved by the cabinet to prevent seepage or to
provide stability.
(3) Diversions
shall be designed, constructed, and maintained in a manner which prevents
additional contributions of suspended solids to stream flow and to run off
outside the permit area, to the extent possible using the best technology
currently available. Appropriate sediment control measures for these diversions
may include, but not be limited to, maintenance of appropriate gradients,
channel lining, revegetation, roughness structures, and detention
basins.
(4) No diversion shall be
located so as to increase the potential for land slides. No diversion shall be
constructed on existing land slides, unless approved by the cabinet.
(6) Diversion design shall incorporate the
following:
(a) Channel lining shall be
designed using standard engineering practices to pass safely the design
velocities.
(b) Freeboard shall be
no less than three-tenths (0.3) feet. Protection shall be provided for
transition of flows and for critical areas such as swales and curves. Where the
area protected is a critical area as determined by the cabinet, the design
freeboard may be increased.
(c)
Energy dissipators shall be installed, when necessary, at discharge points,
where diversions intersect with natural streams and exit velocity of the
diversion ditch flow is greater than that of the receiving stream.
(d) Excess excavated material not necessary
for
diversion channel geometry or regrading of the channel shall be disposed of
in accordance with the plan approved by the
cabinet and submitted under
405 KAR
30:130, Section 6(13).
Section 2. Stream
Channel Diversions.
(1) Flow from perennial
and intermittent streams within the
permit area may be diverted, if the
diversions:
(a) Comply with applicable local,
state, and federal statutes and regulations;
(b) Pass the design flow (100 year storm)
without causing an increase of more than one (1) foot over existing flood
heights or an increase in potential flood hazard to life and/or property;
and
(c) Pass the design velocities
without causing any significant increase in flow velocities.
(2) When stream flow is allowed to
be diverted, the stream channel
diversion shall be designed, constructed, and
removed, in accordance with the following:
(a)
The longitudinal profile of the stream, the channel, and the flood plain shall
be designed and constructed to remain stable and to prevent, to the extent
possible using the best technology currently available, additional
contributions of suspended solids to stream flow or to run off outside the
permit area. These contributions shall not be in excess of requirements of
state or federal law. Erosion control structures such as channel lining
structures, retention basins, and artificial roughness structures shall be used
in diversions only when approved by the cabinet as being necessary to control
erosion. These structures shall be approved for permanent diversions only where
they are stable and will require infrequent maintenance.
(b) The combination of channel, bank, and
flood plain configurations shall be adequate to pass safely the peak run-off of
a ten (10) year, twenty-four (24) hour precipitation event for temporary
diversions, a 100-year, twenty-four (24) hour precipitation event for permanent
diversions, with drainage areas less than 200 acres, or larger events specified
by the cabinet for drainage areas greater than 200 acres. However, the capacity
of the channel itself should be at least equal to the capacity of the
unmodified stream channel immediately upstream and downstream of the
diversion.
(3) When no
longer needed to achieve the purpose for which they were authorized, all
temporary stream channel diversions shall be removed and the affected land
regraded and revegetated, in accordance with
405 KAR 30:290,
405 KAR
30:390, and
405 KAR 30:400. At
the time diversions are removed, downstream water treatment facilities
previously protected by the
diversion shall be modified or removed to prevent
overtopping or failure of the facilities. This requirement shall not relieve
the permittee from maintenance of a water treatment facility otherwise required
under 405 KAR or the permit.
(4)
When permanent diversions are constructed or stream channels restored, after
temporary diversions, the
permittee shall:
(a) Restore, enhance where practicable, or
maintain natural riparian vegetation on the banks of the stream;
(b) Establish or restore the stream to an
environmentally acceptable meandering shape and gradient, as determined by the
cabinet; and
(c) Establish or
restore the stream to a longitudinal profile and cross-section, including
aquatic habitats (usually a pattern of riffles, pools, and drops rather than
uniform depth) that approximate premining stream channel
characteristics.
Section
3. Stream Buffer Zones.
(1) No
land within 100 feet of a
perennial stream or a stream with a biological
community determined according to subsection (3) of this section shall be
disturbed by oil shale operations unless the
cabinet specifically authorizes
such activities closer to or through such a stream under the following
conditions.
(a) Any temporary or permanent
diversion shall comply with all provisions of this administrative regulation
and shall be constructed prior to any disturbance of the buffer zone;
(b) That the original stream channel will be
restored or relocated in a manner satisfactory to the cabinet; and
(c) During and after the mining, the water
quantity and quality from the stream section within 100 feet of the surface
mining activities shall not be adversely affected.
(2) The area not to be
disturbed shall be
designated a buffer zone and marked as specified in
405 KAR
30:210.
(3) A stream with a biological community
shall be determined by the existence in the stream at any time of an assemblage
of two (2) or more species of arthropods or mulluscan animals which are:
(a) Adapted to flowing water for all or part
of their life cycle;
(b) Dependent
upon a flowing water habitat;
(c)
Reproducing or can reasonably be expected to reproduce in the water body where
they are found; and
(d) Longer than
two (2) millimeters at some stage of the part of their life cycle spent in the
flowing water habitat.