(f)
Unstable areas.
(1) Owners or operators of
new MSWLF units and existing units located in an unstable area shall
demonstrate to the department that engineering measures have been incorporated
into the unit's design to ensure that the integrity of the structural
components of the MSWLF unit will not be disrupted. The owner or operator shall
consider the following factors, at a minimum, when determining whether an area
is unstable:
(A) on-site or local soil
conditions that may result in significant differential settling;
(B) on-site or local geologic or
geomorphologic features; and
(C)
on-site or local human-made features or events both surface and subsurface.
(2) The owner or
operator shall place a copy of the demonstration in the operating record.
(3) For purposes of this
subsection:
(A) "Unstable area" means a
location that is susceptible to natural or human-induced events or forces
capable of impairing the integrity of some or all of the MSWLF structural
components responsible for preventing releases from a landfill. Unstable areas
may include poor foundation conditions, areas susceptible to mass movements,
and karst terranes.
(B)
"Structural components" means liners, leachate collection systems, final
covers, run-on systems, run-off systems, and any other component used in the
construction and operation of the MSWLF that is necessary for protection of
human health and the environment.
(C) "Poor foundation conditions" means those
areas where features exist which indicate that a natural or human-induced event
may result in inadequate foundation support for the structural components of an
MSWLF unit.
(D) "Areas susceptible
to mass movement" means those areas of influence including areas characterized
as having an active or substantial possibility of mass movement, where the
movement of earth material at, beneath, or adjacent to the MSWLF unit, because
of natural or man-induced events, results in the downslope transport of soil
and rock material by means of gravitational influence. Areas of mass movement
may include:
(iii) debris slides and flows;
(E) "Karst terranes" means areas where karst
topography, with its characteristic surface and subterranean features, is
developed as the result of dissolution of limestone, dolomite, or other soluble
rock. Characteristic physiographic features present in karst terranes may
include: