Current through Register Vol. 24-06, March 15, 2024
(1)
Applicability.
(a) The regulations in this
section apply to owners and operators of facilities that store or treat
dangerous waste in piles.
(b) The
regulations in this section do not apply to owners or operators of waste piles
that will be closed with wastes left in place. Such waste piles are subject to
regulation under WAC
173-303-665
(Landfills).
(c) The owner or
operator of any waste pile that is inside or under a structure that provides
protection from precipitation so that neither runoff nor leachate is generated
is not subject to regulation under subsection (2) of this section, or under WAC
173-303-645, provided that:
(i) Liquids or materials containing free
liquids are not placed in the pile;
(ii) The pile is protected from surface water
run-on by the structure or in some other manner;
(iii) The pile is designed and operated to
control dispersal of the waste by wind, by means other than wetting;
and
(iv) The pile will not generate
leachate through decomposition or other reactions.
(d) Reserve.
(2) Design and operating requirements.
(a) A waste pile (except for an existing
portion of a waste pile) must have:
(i) A
liner that is designed, constructed, installed and maintained to prevent any
migration of wastes out of the pile into the adjacent subsurface soil or
groundwater or surface water at any time during the active life (including the
closure period) of the waste pile. The liner may be constructed of materials
that may allow waste to migrate into the liner itself (but not into the
adjacent subsurface soil or groundwater or surface water) during the active
life of the facility. The liner must be:
(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; and
(C)
Installed to cover all surrounding earth likely to be in contact with the waste
or leachate; and
(ii) A
leachate collection and removal system immediately above the liner that is
designed, constructed, maintained, and operated to collect and remove leachate
from the pile. 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:
(A) Constructed of materials that are:
(I) Chemically resistant to the waste managed
in the pile and to the leachate expected to be generated; and
(II) Of sufficient strength and thickness to
prevent collapse under the pressures exerted by overlaying wastes, waste cover
materials, and by any equipment used at the pile; and
(B) Designed and operated to function without
clogging through the scheduled closure of the waste pile.
(b) A liner and leachate
collection and removal system must be protected from plant growth which could
adversely affect any component of the system.
(c) The owner or operator must submit an
engineering report with his permit application stating the basis for selecting
the liner required in subsection (2)(a)(i) of this section. The statement must
be certified by an independent, qualified registered professional
engineer.
(d) The owner or operator
will be exempted from the requirements of (a), (b), and (c) of this subsection,
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 dangerous constituents
identified under WAC
173-303-645(4)
into the groundwater or surface water at any future time. In deciding whether
to grant an exemption, the department will consider:
(i) The nature and quantity of the
wastes;
(ii) The proposed alternate
design and operation;
(iii) The
hydrogeologic setting of the facility, including attenuative capacity and
thickness of the liners and soils present between the pile and groundwater or
surface water; and
(iv) 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.
(e) The owner or operator must
design, construct, operate, and maintain a run-on control system capable of
preventing flow onto any portion of the pile during peak discharge from at
least a twenty-five-year storm.
(f)
The owner or operator must design, construct, operate, and maintain a runoff
management system to collect and control at least the water volume resulting
from a twenty-four-hour, twenty-five-year storm.
(g) Collection and holding facilities (e.g.,
tanks or basins) associated with run-on and runoff control systems must be
emptied or otherwise managed expeditiously and in accordance with this chapter
after storms to maintain design capacity of the system.
(h) If the pile contains any particulate
matter which may be subject to wind dispersal, the owner or operator must cover
or otherwise manage the pile to control wind dispersal.
(i) The department will specify in the permit
all design and operating practices that are necessary to ensure that the
requirements of this subsection are satisfied.
(j) The owner or operator of each new waste
pile unit, each lateral expansion of a waste pile unit, and each replacement of
an existing waste pile unit must install two or more liners and a leachate
collection and removal system above and between such liners.
(i) The liner system must include:
(A) A top liner designed and constructed of
materials (e.g., a geomembrane) to prevent the migration of dangerous
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 dangerous 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 dangerous 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.
(C) The liners must comply
with (a)(i), (A), (B), and (C) of this subsection.
(ii) 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 waste pile 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 twelve inches (30.5 cm). The leachate collection and
removal system must comply with (j)(iii) (D) and (E) of this
subsection.
(iii) 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 dangerous 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:
(A) Constructed with a bottom slope of one
percent or more;
(B) 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
m2/sec or more:
(C) Constructed of materials that are
chemically resistant to the waste managed in the waste pile 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 waste pile;
(D) Designed and operated to minimize
clogging during the active life and post-closure care period; and
(E) 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.
(iv) The owner or operator will collect and
remove pumpable liquids in the leak detection system sumps to minimize the head
on the bottom liner.
(v) 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.
(k) The
department may approve alternative design or operating practices to those
specified in (j) of this subsection if the owner or operator demonstrates to
the department that such design and operating practices, together with location
characteristics:
(i) Will prevent the
migration of any dangerous constituent into the groundwater or surface water at
least as effectively as the liners and leachate collection and removal systems
specified in (c) of this subsection; and
(ii) Will allow detection of leaks of
dangerous constituents through the top liner at least as effectively.
(l) Subitem (j) of this subsection
does not apply to mono-fills that are granted a waiver by the department in
accordance with WAC
173-303-650(2)(l).
(m) The owner or operator of any replacement
waste pile unit is exempt from (j) of this subsection if:
(i) 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; and
(ii) There is no reason to believe that the
liner is not functioning as designed.
(3) Action leakage rate.
(a) The department must approve an action
leakage rate for waste piles subject to subsection (2)(j) or (k) of this
section. The action leakage rate is the maximum design flow rate that the leak
detection system (LDS) can remove without the fluid head on the bottom liner
exceeding 1 foot. The action leakage rate must include an adequate safety
margin to allow for uncertainties in the design (e.g., slope, hydraulic
conductivity, thickness of drainage material), construction, operation, and
location of the LDS, waste and leachate characteristics, likelihood and amounts
of other sources of liquids in the LDS, and proposed response actions (e.g.,
the action leakage rate must consider decreases in the flow capacity of the
system over time resulting from siltation and clogging, rib layover and creep
of synthetic components of the system, overburden pressures, etc.).
(b) To determine if the action leakage rate
has been exceeded, the owner or operator must convert the weekly flow rate from
the monitoring data obtained under subsection (5)(c) of this section to an
average daily flow rate (gallons per acre per day) for each sump. Unless the
department approves a different calculation, the average daily flow rate for
each sump must be calculated weekly during the active life and closure
period.
(4) Response
actions.
(a) The owner or operator of waste
pile units subject to subsection (2)(j) or (k) of this section must have an
approved response action plan before receipt of waste. The response action plan
must set forth the actions to be taken if the action leakage rate has been
exceeded. At a minimum, the response action plan must describe the actions
specified in (b) of this subsection.
(b) If the flow rate into the leak detection
system exceeds the action leakage rate for any sump, the owner or operator
must:
(i) Notify the department in writing of
the exceedance within seven days of the determination;
(ii) Submit a preliminary written assessment
to the department within fourteen days of the determination, as to the amount
of liquids, likely sources of liquids, possible location, size, and cause of
any leaks, and short-term actions taken and planned;
(iii) Determine to the extent practicable the
location, size, and cause of any leak;
(iv) Determine whether waste receipt should
cease or be curtailed, whether any waste should be removed from the unit for
inspection, repairs, or controls, and whether or not the unit should be
closed;
(v) Determine any other
short-term and long-term actions to be taken to mitigate or stop any leaks;
and
(vi) Within thirty days after
the notification that the action leakage rate has been exceeded, submit to the
department the results of the analyses specified in (b) of this subsection and
in subsections (3), (4), and (5) of this section, the results of actions taken,
and actions planned. Monthly thereafter, as long as the flow rate in the leak
detection system exceeds the action leakage rate, the owner or operator must
submit to the department a report summarizing the results of any remedial
actions taken and actions planned.
(c) To make the leak and/or remediation
determinations in (b) (C), (D), and (E) of this subsection, the owner or
operator must:
(i)
(A) Assess the source of liquids and amounts
of liquids by source;
(B) Conduct a
fingerprint, dangerous constituent, or other analyses of the liquids in the
leak detection system to identify the source of liquids and possible location
of any leaks, and the hazard and mobility of the liquid; and
(C) Assess the seriousness of any leaks in
terms of potential for escaping into the environment; or
(ii) Document why such assessments are not
needed.
(5)
Monitoring and inspection.
(a) During
construction or installation, liners (except in the case of existing portions
of piles exempt from subsection (2)(a) of this section), and cover systems
(e.g., membranes, sheets, coatings) must be inspected for uniformity, damage,
and imperfections (e.g., holes, cracks, thin spots, foreign materials).
Immediately after construction or installation:
(i) Synthetic liners and covers must be
inspected to ensure tight seams and joints and the absence of tears, punctures,
or blisters; and
(ii) Soil-based
and admixed liners and covers must be inspected for imperfections including
lenses, cracks, channels, root holes, or other structural nonuniformities that
may cause an increase in the permeability of the liner or cover.
(b) While a waste pile is in
operation, it must be inspected weekly and after storms to detect evidence of
any of the following:
(i) Deterioration,
malfunctions, or improper operation of run-on and runoff control
systems;
(ii) Proper functioning of
wind dispersal control systems; and
(iii) The presence of leachate in and proper
functioning of leachate collection and removal systems, where
present.
(c) An owner or
operator required to have a leak detection system under subsection (2)(j) of
this section must record the amount of liquids removed from each leak detection
system sump at least once each week during the active life and closure
period.
(6) Containment
system repairs((___)) - Contingency plans.
(a)
Whenever there is any indication of a possible failure of the containment
system, that system must be inspected in accordance with the provisions of the
containment system evaluation and repair plan required by (d) of this
subsection. Indications of possible failure of the containment system include
liquid detected in the leachate detection system, evidence of leakage or the
potential for leakage in the base, erosion of the base, or apparent or
potential deterioration of the liner(s) based on observation or test samples of
the liner materials.
(b) Whenever
there is a positive indication of a failure of the containment system, the
waste pile must be removed from service. Indications of positive failure of the
containment system include waste detected in the leachate detection system, or
a breach (e.g., a hole, tear, crack, or separation) in the base.
(c) If the waste pile must be removed from
service as required by (b) of this subsection, the owner or operator must:
(i) Immediately stop adding wastes to the
pile;
(ii) Immediately contain any
leakage which has occurred or is occurring;
(iii) Immediately cause the leak to be
stopped; and
(iv) If the leak
cannot be stopped by any other means, remove the waste from the base.
(d) As part of the contingency
plan required in WAC
173-303-350, the owner or
operator must specify:
(i) A procedure for
complying with the requirements of (c) of this subsection; and
(ii) A containment system evaluation and
repair plan describing: Testing and monitoring techniques; procedures to be
followed to evaluate the integrity of the containment system in the event of a
possible failure; a schedule of actions to be taken in the event of a possible
failure; and a description of the repair techniques and materials (and their
availability) to be used in the event of leakage due to containment system
failure or deterioration which does not require the waste pile to be removed
from service. For EHW piles, the owner or operator must submit with his permit
application a statement signed by an independent, qualified registered
professional engineer of the basis on which the evaluation and repair plan has
been established.
(e) No
waste pile that has been removed from service pursuant to (b) of this
subsection, may be restored to service unless:
(i) The containment system has been repaired;
and
(ii) The containment system has
been certified by an independent qualified registered professional engineer as
meeting the design specifications approved in the permit.
(f) A waste pile that has been removed from
service pursuant to (b) of this subsection, and will not be repaired, must be
closed in accordance with subsection (9) of this section.
(7) Special requirements for ignitable or
reactive waste. Ignitable or reactive waste must not be placed in a waste pile,
unless the waste and waste pile satisfy all applicable requirements of WAC
173-303-140(2)(a),
and:
(a) Addition of the waste to an existing
pile results in the waste or mixture no longer meeting the definition of
ignitable or reactive waste under WAC
173-303-090, and complies with
WAC 173-303-395(1)(b);
or
(b)
(i) The waste is managed in such a way that
it is protected from any material or conditions which may cause it to ignite or
react; and
(ii) The generator
complies with WAC
173-303-395(1)(d).
(8) Special
requirements for incompatible wastes.
(a)
Incompatible wastes, or incompatible wastes and materials must not be placed in
the same pile, unless WAC
173-303-395(1)(b)
is complied with.
(b) A pile of dangerous waste that is
incompatible with any waste or other material stored nearby in other
containers, piles, open tanks, or surface impoundments must be separated from
the other materials, or protected from them by means of a dike, berm, wall, or
other device. Piles of incompatible wastes must not be served by the same
containment system.
(c) Dangerous
waste must not be piled on the same base where incompatible wastes or materials
were previously piled, unless the base has been decontaminated sufficiently to
ensure compliance with WAC
173-303-395(1)(b).
(9) Closure and post-closure care.
(a) At closure, the owner or operator must
remove or decontaminate all dangerous waste, waste residues, contaminated
containment system components (liners, etc.), contaminated subsoils, and
structures and equipment contaminated with waste and leachate, and manage them
in accordance with this chapter.
(b) If, after removing or decontaminating all
residues and making all reasonable efforts regarding removal or decontamination
of contaminated components, subsoils, structures, and equipment as required in
(a) of this subsection, the owner or operator finds that not all contaminated
subsoils can be practicably removed or decontaminated (except that no EHW may
ever be left in place), he must close the facility and perform post-closure
care in accordance with the closure and post-closure care requirements that
apply to landfills, WAC
173-303-665(6).
(c)
(i) The
owner or operator of a waste pile that does not comply with the liner
requirements of subsection (2)(a)(i) of this section, and is not exempt from
them in accordance with subsection (1)(c) or (2)(d) of this section, must:
(A) Include in the closure plan for the pile
under WAC
173-303-610(3)
both a plan for complying with (a) of this subsection, and a contingent plan
for complying with (b) of this subsection, in case not all contaminated
subsoils can be practicably removed at closure; and
(B) Prepare a contingent post-closure plan
under WAC
173-303-610(8)
for complying with (b) of this subsection, in case not all contaminated
subsoils can be practicably removed at closure.
(ii) The cost estimates calculated under WAC
173-303-620(3) and
(5) for closure and post-closure care of a
pile must include the cost of complying with the contingent closure plan and
the contingent post-closure plan but are not required to include the cost of
expected closure under (a) of this subsection.
(10) Special requirements for dangerous
wastes F020, F021, F022, F023, F026, and F027.
(a) Dangerous wastes F020, F021, F022, F023,
F026, and F027 must not be placed in waste piles that are not enclosed (as
defined in subsection (1)(c) of this section) unless the owner or operator
operates the waste pile in accordance with a management plan for these wastes
that is approved by the department pursuant to the standards set out in this
subsection, and in accord with all other applicable requirements of this
chapter. The factors to be considered are:
(i) The volume, physical, and chemical
characteristics of the wastes, including their potential to migrate through
soil or to volatilize or escape into the atmosphere;
(ii) The attenuative properties of underlying
and surrounding soils or other materials;
(iii) The mobilizing properties of other
materials co-disposed with these wastes; and
(iv) The effectiveness of additional
treatment, design, or monitoring techniques.
(b) The department may determine that
additional design, operating, and monitoring requirements are necessary in
order to reduce the possibility of migration of these wastes to groundwater, to
surface water, or air so as to protect human health and the
environment.
Statutory Authority:
Chapters
70.105 and
70.105D RCW. 09-14-105 (Order
07-12), § 173-303-660, filed 6/30/09, effective 7/31/09; 95-22-008 (Order
94-30), § 173-303-660, filed 10/19/95, effective 11/19/95; 94-01-060
(Order 92-33), § 173-303-660, filed 12/8/93, effective 1/8/94. Statutory
Authority:
Chapter
70.105 RCW. 87-14-029
(Order DE-87-4), § 173-303-660, filed 6/26/87; 86-12-057 (Order DE-85-10),
§ 173-303-660, filed 6/3/86; 84-09-088 (Order DE 83-36), §
173-303-660, filed 4/18/84. Statutory Authority:
RCW
70.95.260 and
chapter
70.105 RCW. 82-05-023
(Order DE 81-33), § 173-303-660, filed
2/10/82.