Current through August 26, 2024
(1) Any surface
impoundment that is not covered by sub. (3) or s.
NR 665.0221 shall have a liner for all portions of the
impoundment (except for existing portions of the impoundment). The liner shall
be designed, constructed and installed to prevent any migration of wastes out
of the impoundment to the adjacent subsurface soil or groundwater or surface
water at any time during the active life (including the closure period) of the
impoundment. The liner may be constructed of materials that may allow wastes to
migrate into the liner (but not into the adjacent subsurface soil or
groundwater or surface water) during the active life of the facility, provided
that the impoundment is closed in accordance with s.
NR 664.0228(1)
(a). For impoundments that will be closed in
accordance with s.
NR 664.0228(1)
(b), the liner shall be constructed of
materials that can prevent wastes from migrating into the liner during the
active life of the facility. The liner shall be all of the following:
(a) Constructed of materials that have
appropriate chemical properties and sufficient strength and thickness to
prevent failure due to pressure gradients (including static head and external
hydrogeologic forces), physical contact with the waste or leachate to which
they are exposed, climatic conditions, the stress of installation and the
stress of daily operation.
(b)
Placed upon a foundation or base capable of providing support to the liner and
resistance to pressure gradients above and below the liner to prevent failure
of the liner due to settlement, compression or uplift.
(c) Installed to cover all surrounding earth
likely to be in contact with the waste or leachate.
(2) The owner or operator will be exempted
from the requirements of sub. (1) if the department finds, based on a
demonstration by the owner or operator, that alternate design and operating
practices, together with location characteristics, will prevent the migration
of any hazardous constituents (see s.
NR 664.0093) into the groundwater or surface water at
any future time. In deciding whether to grant an exemption, the department will
consider all of the following:
(a) The nature
and quantity of the wastes.
(b) The
proposed alternate design and operation.
(c) The hydrogeologic setting of the
facility, including the attenuative capacity and thickness of the liners and
soils present between the impoundment and groundwater or surface
water.
(d) All other factors which
would influence the quality and mobility of the leachate produced and the
potential for it to migrate to groundwater or surface
water.
(3) The owner or
operator of each new surface impoundment unit on which construction commences
after June 1, 1995, each lateral expansion of a surface impoundment unit on
which construction commences after June 1, 1995 and each replacement of an
existing surface impoundment unit that is to commence reuse after June 1, 1995
shall install 2 or more liners and a leachate collection and removal system
between the liners. "Construction commences" is as defined in s.
NR 660.10 under "existing facility".
(a)
1. The
liner system shall include both of the following:
a. A top liner designed and constructed of
materials (e.g., a geomembrane) to prevent the migration of hazardous
constituents into the liner during the active life and long-term care
period.
b. A composite bottom
liner, consisting of at least 2 components. The upper component shall be
designed and constructed of materials (e.g., a geomembrane) to prevent the
migration of hazardous constituents into this component during the active life
and long-term care period. The lower component shall be designed and
constructed of materials to minimize the migration of hazardous constituents if
a breach in the upper component were to occur. The lower component shall be
constructed of at least 3 feet (91 cm) of compacted soil material with a
hydraulic conductivity of no more than 1x10 -7 cm/sec.
2. The liners shall comply with sub. (1) (a),
(b) and (c).
(b) The
leachate collection and removal system between the liners, and immediately
above the bottom composite liner in the case of multiple leachate collection
and removal systems, is also a leak detection system
. This
leak detection system shall be capable of detecting, collecting and removing
leaks of hazardous constituents at the earliest practicable time through all
areas of the top liner likely to be exposed to waste or leachate during the
active life and long-term care period. The requirements for a leak detection
system in this subsection are satisfied by installation of a system that is, at
a minimum, all of the following:
1.
Constructed with a bottom slope of 1% or more.
2. Constructed of granular drainage materials
with a hydraulic conductivity of 1x10 -1 cm/sec or more and a thickness of 12
inches (30.5 cm) or more; or constructed of synthetic or geonet drainage
materials with a transmissivity of 3x10 -4 m 2/sec or more.
3. Constructed of materials that are
chemically resistant to the waste managed in the surface impoundment and the
leachate expected to be generated, and of sufficient strength and thickness to
prevent collapse under the pressures exerted by overlying wastes and any waste
cover materials or equipment used at the surface impoundment.
4. Designed and operated to minimize clogging
during the active life and long-term care period.
5. Constructed with sumps and liquid removal
methods (e.g., pumps) of sufficient size to collect and remove liquids from the
sump and prevent liquids from backing up into the drainage layer. Each unit
shall have its own sump. The design of each sump and removal system shall
provide a method for measuring and recording the volume of liquids present in
the sump and of liquids removed.
(c) The owner or operator shall collect and
remove pumpable liquids in the sumps to minimize the head on the bottom
liner.
(d) The owner or operator of
a leak detection system that is not located completely above the seasonal high
water table shall demonstrate that the operation of the leak detection system
will not be adversely affected by the presence of
groundwater.
(4) The
department may approve alternative design or operating practices to those
specified in sub. (3) if the owner or operator demonstrates to the department
that the design and operating practices, together with location
characteristics, will do both of the following:
(a) Prevent the migration of any hazardous
constituent into the groundwater or surface water at least as effectively as
the liners and leachate collection and removal system specified in sub.
(3).
(b) Allow detection of leaks
of hazardous constituents through the top liner at least as
effectively.
(5) The
double liner requirement in sub. (3) may be waived by the department for any
monofill, if the requirements of pars. (a) and (b) 1. or 2. are met:
(a) The monofill contains only hazardous
wastes from foundry furnace emission controls or metal casting molding sand,
and the wastes do not contain constituents which would render the wastes
hazardous for reasons other than the toxicity characteristic in s. NR 661.0024.
(b)
1. All of the following:
a. The monofill has at least one liner for
which there is no evidence that the liner is leaking. For the purposes of this
subsection, the term "liner" means a liner designed, constructed, installed and
operated to prevent hazardous waste from passing into the liner at any time
during the active life of the facility, or a liner designed, constructed,
installed and operated to prevent hazardous waste from migrating beyond the
liner to adjacent subsurface soil, groundwater or surface water at any time
during the active life of the facility. In the case of any surface impoundment
which has been exempted from the requirements of sub. (3) on the basis of a
liner designed, constructed, installed and operated to prevent hazardous waste
from passing beyond the liner, at the closure of the impoundment, the owner or
operator shall remove or decontaminate all waste residues, all contaminated
liner material and contaminated soil to the extent practicable. If all
contaminated soil is not removed or decontaminated, the owner or operator of
the impoundment will comply with appropriate long-term care requirements,
including but not limited to groundwater monitoring and corrective
action.
b. The monofill is located
more than one-quarter mile from an underground source of drinking water (as
that term is defined in
40
CFR 144.3).
c. The monofill is in compliance with
generally applicable groundwater monitoring requirements for facilities with
operating licenses under s.
291.25,
Stats.
2. The owner or
operator demonstrates that the monofill is located, designed and operated so as
to assure that there will be no migration of any hazardous constituent into
groundwater or surface water at any future time.
(6) The owner or operator of any replacement
surface impoundment unit is exempt from sub. (3) if both of the following
apply:
(a) The existing unit was constructed
in compliance with the design standards of
42
USC 6924(o)(1)(A)(i) and
(5).
(b) There is no reason to believe that the
liner is not functioning as designed.
(7) A surface impoundment shall be designed,
constructed, maintained and operated to prevent overtopping resulting from
normal or abnormal operations; overfilling; wind and wave action; rainfall;
run-on; malfunctions of level controllers, alarms and other equipment and human
error.
(8) A surface impoundment
shall have dikes that are designed, constructed and maintained with sufficient
structural integrity to prevent massive failure of the dikes. In ensuring
structural integrity, it may not be presumed that the liner system will
function without leakage during the active life of the unit.
(9) The department shall specify in the
operating license all design and operating practices that are necessary to
ensure that the requirements of this section are satisfied.
