Current through Register Vol. 47, No. 17, September 10, 2024
(a)
Any landfill that is not covered by paragraph (c) of this section or §
265.301(a) of these regulations must have a liner system for all portions of
the landfill (except for existing portions of such landfill). The liner system
must have:
(1) A liner that is designed,
constructed, and installed to prevent any migration of wastes out of the
landfill to the adjacent subsurface soil or ground water or surface water at
anytime during the active life (including the closure period) of the landfill.
The liner must be constructed of materials that prevent wastes from passing
into the liner during the active life of the facility. The liner must be:
(i) 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;
(ii)
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; and
(iii) Installed to cover all surrounding
earth likely to be in contact with the waste or leachate; and
(2) A leachate collection and
removal system immediately above the liner that is designed, constructed,
maintained, and operated to collect and remove leachate from the landfill. The
Department will specify design and operating conditions in the permit to ensure
that the leachate depth over the liner does not exceed 30 cm (one foot). The
leachate collection and removal system must be:
(i) Constructed of materials that are:
(A) Chemically resistant to the waste managed
in the landfill and the leachate expected to be generated; and
(B) Of sufficient strength and thickness to
prevent collapse under the pressures exerted by overlying wastes, waste cover
materials, and by any equipment used at the landfill; and
(ii) Designed and operated to function
without clogging through the scheduled closure of the landfill.
(b) The owner or
operator will be exempted from the requirements of paragraph (a) of this
section if the Department finds, based on a demonstration by the owner or
operator, that alternative design and operating practices, together with
location characteristics, will prevent the migration of any hazardous
constituents (see § 264.93) into the ground water or surface water at any
future time. In deciding whether to grant an exemption, the Department will
consider:
(1) The nature and quantity of the
wastes;
(2) The proposed alternate
design and operation;
(3) The
hydrogeologic setting of the facility, including the attenuative capacity and
thickness of the liners and soils present between the landfill and ground water
or surface water; and
(4) All other
factors which would influence the quality and mobility of the leachate produced
and the potential for it to migrate to ground water or surface water.
(c) The owner or operator of each
new landfill unit on which construction commences after January 29, 1992, each
lateral expansion of a landfill unit on which construction commences after July
29, 1992, and each replacement of an existing landfill unit that is to commence
reuse after July 29, 1992 must install two or more liners and a leachate
collection and removal system above and between such liners. "Construction
commences" is as defined in § 260.10 of these regulations under "existing
facility".
(1)
(i) The
liner system must
include:
(A) A top liner designed and
constructed of materials (e.g., a geomembrane) to prevent the migration of
hazardous constituents into such liner during the active life and post-closure
care period; and
(B) A composite
bottom liner, consisting of at least two components. The upper component must
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 post-closure care period. The lower component must 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 must be
constructed of at least 3 feet (91 cm) of compacted soil material with a
hydraulic conductivity of no more than 1 x 10
-7 cm/sec.
(ii) The liners must comply with paragraphs
(a)(1)(i), (ii), and (iii) of this section.
(2) The leachate collection and removal
system immediately above the top liner must be designed, constructed, operated,
and maintained to collect and remove leachate from the landfill during the
active life and post-closure care period. The Department will specify design
and operating conditions in the permit to ensure that the leachate depth over
the liner does not exceed 30 cm (one foot). The leachate collection and removal
system must comply with paragraphs (c)(3)(iii) and (iv) of this
section.
(3) 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 must 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 post-closure care
period. The requirements for a leak detection system in this paragraph are
satisfied by installation of a system that is, at a minimum:
(i) Constructed with a bottom slope of one
percent or more;
(ii) Constructed
of granular drainage materials with a hydraulic conductivity of 1 x 10
-2 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 3 x 10
-5 m
2 /sec or more;
(iii) Constructed of materials that are
chemically resistant to the waste managed in the landfill and the leachate
expected to be generated, and of sufficient strength and thickness to prevent
collapse under the pressures exerted by overlying wastes, waste cover
materials, and equipment used at the landfill;
(iv) Designed and operated to minimize
clogging during the active life and post-closure care period; and
(v) 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
must have its own sump(s). The design of each sump and removal system must
provide a method for measuring and recording the volume of liquids present in
the sump and of liquids removed.
(4) The owner or operator shall collect and
remove pumpable liquids in the leak detection system sumps to minimize the head
on the bottom liner.
(5) The owner
or operator of a leak detection system that is not located completely above the
seasonal high water table must demonstrate that the operation of the leak
detection system will not be adversely affected by the presence of ground
water.
(d) The Department
may approve alternative design or operating practices to those specified in
paragraph (c) of this section if the owner or operator demonstrates to the
Department that such design and operating practices, together with location
characteristics:
(1) Will prevent the
migration of any hazardous constituent into the ground water or surface water
at least as effectively as the liners and leachate collection and removal
systems specified in paragraph (c) of this section; and
(2) Will allow detection of leaks of
hazardous constituents through the top liner at least as effectively.
(e) The double liner requirement
set forth in paragraph (c) of this section may be waived by the Department for
any monofill, if:
(1) The monofill contains
only hazardous wastes from foundry furnace emission controls or metal casting
molding sand, and such wastes do not contain constituents which would render
the wastes hazardous for reasons other than the Toxicity Characteristic in
§ 261.24 of these regulations, with EPA Hazardous Waste Numbers D004
through D017; and
(2)
(i)
(A) The
monofill has at least one liner for which there is no evidence that the liner
is leaking;
(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);
and
(C) The monofill is in
compliance with generally applicable ground water monitoring requirements for
facilities with permits under RCRA 3005(c) [42 U.S.C. §
6925(c)] ;
or
(ii) 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
ground water or surface water at any future time.
(f) The owner or operator of any replacement
landfill unit is exempt from paragraph (c) of this section if:
(1) The existing unit was constructed in
compliance with the design standards of section 3004(o)(1)(A)(i) and (o)(5) of
the Resource Conservation and Recovery Act [42 U.S.C §
6924(o)] ; and
(2) There is no reason to believe that the
liner is not functioning as designed.
(g) The owner or operator must design,
construct, operate, and maintain a run-on control system capable of preventing
flow onto the active portion of the landfill during peak discharge from at
least a 100-year storm.
(h) The
owner or operator must design, construct, operate, and maintain a run-off
management system to collect and control at least the water volume resulting
from a 24-hour, 100-year storm.
(i)
Collection and holding facilities(e.g., tanks or basins) associated with run-on
and run-off control systems must be emptied or otherwise managed expeditiously
after storms to maintain design capacity of the system.
(j) If the landfill contains any particulate
matter which may be subject to wind dispersal, the owner or operator must cover
or otherwise manage the landfill to control wind dispersal.
(k) The Department will specify in the permit
all design and operating practices that are necessary to ensure that the
requirements of this section are satisfied.
