Current through Register Vol. 24-06, March 15, 2024
(1) The department must designate a CAMU that
will be used for storage and/or treatment only in accordance with subsection
(4) of this section. When designating all other CAMUs, the department will do
so in accordance with WAC
173-303-64650 and
173-303-64670, and the following:
(a) The CAMU will facilitate the
implementation of reliable, effective, protective, and cost-effective
remedies;
(b) Waste management
activities associated with the CAMU will not create unacceptable risks to
humans or the environment resulting from exposure to dangerous wastes or
dangerous constituents;
(c) The
CAMU will include uncontaminated areas of the facility only if including such
areas for the purposes of managing CAMU-eligible wastes is more protective than
management of such wastes at contaminated areas of the facility;
(d) Areas within the CAMU where wastes remain
in place after closure of the CAMU, will be managed and contained so as to
minimize future releases of dangerous wastes and dangerous constituents to the
extent practicable;
(e) When
appropriate and practicable, the CAMU will expedite the timing of remedial
activity implementation;
(f) The
CAMU will enable the use, when appropriate, of treatment technologies
(including innovative technologies) to enhance the long-term effectiveness of
remedial actions by reducing the toxicity, mobility, or volume of wastes that
will remain in place after closure of the CAMU; and
(g) The CAMU will, to the extent practicable,
minimize the land area of the facility upon which wastes will remain in place
after closure of the CAMU.
(2) The owner/operator must provide
sufficient information to enable the department to designate a CAMU in
accordance with the criteria in this section. This must include, unless not
reasonably available, information on:
(a) The
origin of the waste and how it was subsequently managed (including a
description of the timing and circumstances surrounding the disposal and/or
release);
(b) Whether the waste was
listed or identified as dangerous at the time of disposal and/or release;
and
(c) Whether the disposal and/or
release of the waste occurred before or after the land disposal requirements of
40 C.F.R. part 268, which are incorporated by reference at WAC
173-303-140(2)(a),
or, if the waste is a state-only dangerous waste, the land disposal
restrictions of WAC
173-303-140(2)(b),
were in effect for the waste listing, characteristic, or criterion.
(3) When designating a CAMU, the
department will specify, in the permit or order, requirements for the CAMU
including the following:
(a) The areal
configuration of the CAMU;
(b)
Except as provided in subsection (5) of this section, requirements for
CAMU-eligible waste management within the CAMU including specification of
applicable design, operation, treatment, and closure requirements;
(c) Minimum design requirements. CAMUs,
except as provided in subsection (4) of this section, into which wastes are
placed must be designed in accordance with the following:
(i) Unless the department approves alternate
requirements under (c)(ii) of this subsection, CAMUs that consist of new,
replacement, or laterally expanded units must include a composite liner and a
leachate collection system that is designed and constructed to maintain less
than a 30-cm depth of leachate over the liner. For purposes of this subsection,
composite liner means a system consisting of two components; the upper
component must consist of a minimum 30-mil flexible membrane liner (FML)
(geomembrane), and the lower component must consist of at least a two-foot
layer of compacted soil with a hydraulic conductivity of no more than
1x10-7 cm/sec. FML components consisting of high
density polyethylene (HDPE) must be at least 60 mil thick. The FML component
must be installed in direct and uniform contact with the compacted soil
component;
(ii) Alternate
requirements. The department may approve alternate requirements if:
(A) The department finds that alternate
design and operating practices, together with location characteristics, will
prevent the migration of any dangerous constituents into the groundwater or
surface water at least as effectively as the liner and leachate collection
systems in (c)(i) of this subsection; or
(B) The CAMU is to be established in an area
with existing significant levels of contamination, and the department finds
that an alternative design, including a design that does not include a liner,
would prevent migration from the unit that would exceed long-term remedial
goals.
(d)
Minimum treatment requirements: Unless the wastes will be placed in a CAMU for
storage and/or treatment only in accordance with subsection (4) of this
section, CAMU-eligible wastes that, absent this subsection, would be subject to
the treatment requirements of WAC
173-303-140(2),
and that the department determines contain principal hazardous constituents
must be treated to the standards specified in (d)(iii) of this subsection.
(i) Principal hazardous constituents are
those constituents that the department determines pose a risk to human health
and the environment substantially higher than the cleanup levels or goals at
the site.
(A) In general, the department will
designate as principal hazardous constituents:
(I) Carcinogens that pose a potential direct
risk from ingestion or inhalation at the site at or above
10-3; and
(II) Noncarcinogens that pose a potential
direct risk from ingestion or inhalation at the site an order of magnitude or
greater over their reference dose.
(B) The department will also designate
constituents as principal hazardous constituents, where appropriate, when risks
to human health and the environment posed by the potential migration of
constituents in wastes to groundwater are substantially higher than cleanup
levels or goals at the site; when making such a designation, the department may
consider such factors as constituent concentrations, and fate and transport
characteristics under site conditions.
(C) The department may also designate other
constituents as principal hazardous constituents that the department determines
pose a risk to human health and the environment substantially higher than the
cleanup levels or goals at the site.
(ii) In determining which constituents are
"principal hazardous constituents," the department must consider all
constituents which, absent this section, would be subject to the treatment
requirements of WAC
173-303-140(2).
(iii) Waste that the department determines
contains principal hazardous constituents must meet treatment standards
determined in accordance with (d)(iv) or (v) of this subsection.
(iv) Treatment standards for wastes placed in
CAMUs.
(A) For nonmetals, treatment must
achieve 90 percent reduction in total principal hazardous constituent
concentrations, except as provided by (d)(iv)(C) of this subsection.
(B) For metals, treatment must achieve 90
percent reduction in principal hazardous constituent concentrations as measured
in leachate from the treated waste or media (tested according to the TCLP) or
90 percent reduction in total constituent concentrations (when a metal removal
treatment technology is used), except as provided by (d)(iv)(C) of this
subsection.
(C) When treatment of
any principal hazardous constituent to a 90 percent reduction standard would
result in a concentration less than 10 times the Universal Treatment Standard
for that constituent, treatment to achieve constituent concentrations less than
10 times the Universal Treatment Standard is not required. Universal Treatment
Standards are identified in 40 C.F.R. 268.48 Table UTS, which
is incorporated by reference at WAC
173-303-140(2)(a).
(D) For waste exhibiting the dangerous
characteristic of ignitability, corrosivity or reactivity, the waste must also
be treated to eliminate these characteristics.
(E) For debris, the debris must be treated in
accordance with 40 C.F.R.
268.45, which is incorporated by reference at
WAC 173-303-140(2)(a),
or by methods or to levels established under (d)(iv)(A) through (D) of this
subsection or (d)(v) of this subsection, whichever the department determines is
appropriate.
(F) Alternatives to
TCLP. For metal bearing wastes for which metals removal treatment is not used,
the department may specify a leaching test other than the TCLP (SW-846 Method
1311, WAC
173-303-110(3)(a)
) to measure treatment effectiveness,
provided the department determines that an alternative leach testing protocol
is appropriate for use, and that the alternative more accurately reflects
conditions at the site that affect leaching.
(v) Adjusted standards. The department may
adjust the treatment level or method in (d)(iv) of this subsection to a higher
or lower level, based on one or more of the following factors, as appropriate.
The adjusted level or method must be protective of human health and the
environment:
(A) The technical
impracticability of treatment to the levels or by the methods in (d)(iv) of
this subsection;
(B) The levels or
methods in (d)(iv) of this subsection would result in concentrations of
principal hazardous constituents (PHCs) that are significantly above or below
cleanup standards applicable to the site (established either site-specifically,
or promulgated under state or federal law);
(C) The views of the affected local community
on the treatment levels or methods in (d)(iv) of this subsection as applied at
the site, and, for treatment levels, the treatment methods necessary to achieve
these levels;
(D) The short-term
risks presented by the on-site treatment method necessary to achieve the levels
or treatment methods in (d)(iv) of this subsection;
(E) The long-term protection offered by the
engineering design of the CAMU and related engineering controls:
(I) Where the treatment standards in (d)(iv)
of this subsection are substantially met and the principal hazardous
constituents in the waste or residuals are of very low mobility; or
(II) Where cost-effective treatment has been
used and the CAMU meets the liner and leachate collection requirements for new
land disposal units at WAC
173-303-665(2)(h) and
(j); or
(III) Where, after review of appropriate
treatment technologies, the department determines that cost-effective treatment
is not reasonably available, and the CAMU meets the liner and leachate
collection requirements for new land disposal units at WAC
173-303-665(2)(h) and
(j); or
(IV) Where cost-effective treatment has been
used and the principal hazardous constituents in the treated wastes are of very
low mobility; or
(V) Where, after
review of appropriate treatment technologies, the department determines that
cost-effective treatment is not reasonably available, the principal hazardous
constituents in the wastes are of very low mobility, and either the CAMU meets
or exceeds the liner standards for new, replacement, or laterally expanded
CAMUs in (c)(i) and (ii) of this subsection, or the CAMU provides substantially
equivalent or greater protection.
(vi) The treatment required by the treatment
standards must be completed prior to, or within a reasonable time after,
placement in the CAMU.
(vii) For
the purpose of determining whether wastes placed in CAMUs have met
site-specific treatment standards, the department may, as appropriate, specify
a subset of the principal hazardous constituents in the waste as analytical
surrogates for determining whether treatment standards have been met for other
principal dangerous constituents. This specification will be based on the
degree of difficulty of treatment and analysis of constituents with similar
treatment properties.
(e) Except as provided in subsection (4) of
this section, requirements for groundwater and vadose zone monitoring and
corrective action that are sufficient to:
(i)
Continue to detect and to characterize the nature, extent, concentration,
direction, and movement of existing releases of dangerous waste and dangerous
constituents in groundwater from sources located within the CAMU; and
(ii) Detect and subsequently characterize
releases of dangerous waste and dangerous constituents to groundwater that may
occur from areas of the CAMU in which wastes will remain in place after CAMU
closure.
(iii) Require notification
to the department and corrective action as necessary to protect human health
and the environment for releases to groundwater from the CAMU.
(f) Except as provided in
subsection (4) of this section, requirements for closure will minimize the need
for further maintenance; and control, minimize, or eliminate, to the extent
necessary to protect human health and the environment, for areas where wastes
remain in place, post-closure escape of dangerous wastes, dangerous
constituents, leachate, contaminated runoff, or dangerous waste decomposition
products to the ground, to groundwaters, to surface waters, or to the
atmosphere.
(i) Requirements for closure will
include, as appropriate and deemed necessary by the department, the following:
(A) Requirements for excavation, removal,
treatment, and/or containment of wastes; and
(B) Requirements for removal and
decontamination of equipment, devices, and structures used in CAMU-eligible
waste management activities within the CAMU.
(ii) In establishing closure requirements for
CAMUs under subsection (3) of this section, the department will consider the
following factors:
(A) CAMU
characteristics;
(B) Volume of
wastes which will remain in place after CAMU closure;
(C) Potential for releases from the
CAMU;
(D) Physical and chemical
characteristics of the waste;
(E)
Hydrogeological and other relevant environmental conditions at the facility
which may influence the migration of any potential or actual releases in and/or
from the CAMU; and
(F) Potential
for exposure of humans and environmental receptors if releases were to occur at
or from the CAMU.
(iii)
Cap requirements:
(A) At final closure of the
CAMU, for areas in which wastes will remain after closure of the CAMU, with
constituent concentrations at or above remedial levels or goals applicable to
the site, the owner or operator must cover the CAMU with a final cover designed
and constructed to meet the following performance criteria, except as provided
in (f)(iii)(B) of this subsection:
(I) Provide
long-term minimization of migration of liquids through the closed
unit;
(II) Function with minimum
maintenance;
(III) Promote drainage
and minimize erosion or abrasion of the cover;
(IV) Accommodate settling and subsidence so
that the cover's integrity is maintained; and
(V) Have a permeability less than or equal to
the permeability of any bottom liner system or natural subsoils
present.
(B) The
department may determine that modifications to (f)(iii)(A) of this subsection
are needed to facilitate treatment or the performance of the CAMU (e.g., to
promote biodegradation).
(iv) The department will, for areas of the
CAMU in which wastes will remain in place after CAMU closure, specify
post-closure requirements to control, minimize, or eliminate, to the extent
necessary to protect human health and the environment, post-closure escape of
dangerous waste, dangerous constituents, leachate, contaminated runoff, and
dangerous waste decomposition products to the ground, to groundwaters, to
surface waters, and to the atmosphere. Such post-closure requirements will
include, as necessary to protect human health and the environment, monitoring
and maintenance activities and the frequency with which such activities will be
performed to ensure the integrity of any cap, final cover, or other containment
system.
(4)
CAMUs used for storage and/or treatment only are CAMUs in which wastes will not
remain after closure. Such CAMUs must be designated in accordance with all of
the requirements of this subsection, except as follows.
(a) CAMUs that are used for storage and/or
treatment only and that operate in accordance with the time limits established
in the staging pile regulations at
40 C.F.R.
264.554(d)(1)(iii), (h), and
(i) are subject to the requirements for staging piles at
40 C.F.R.
264.554(d)(1)(i) and (ii),
§ 264.554(d)(2), § 264.554(e) and (f), and § 264.554(j) and (k)
in lieu of the performance standards and requirements for CAMUs in this section
at subsections (1) and (3)(c) through (f). The staging pile requirements of 40
C.F.R. Part 264.554 are incorporated by reference at WAC
173-303-64690.
(b) CAMUs that are used for storage and/or
treatment only and that do not operate in accordance with the time limits
established in the staging pile regulations at
40 C.F.R.
264.554(d)(1)(iii), (h), and
(i), which are incorporated by reference:
(i)
Must operate in accordance with a time limit, established by the department,
that is no longer than necessary to achieve a timely remedy selected for the
waste; and
(ii) Are subject to the
requirements for staging piles at
40 C.F.R.
264.554(d)(1)(i) and (ii),
264.554(d)(2),
264.554(e)
and (f), and
264.554(j)
and (k) in lieu of the performance standards
and requirements for CAMUs in this section at subsections (1) and (3)(d) and
(f).
(5)
CAMUs into which wastes are placed where all wastes have constituent levels at
or below remedial levels or goals applicable to the site do not have to comply
with the requirements for liners at subsection (3)(c)(i) of this section, caps
at subsection (3)(f)(iii) of this section, groundwater monitoring requirements
at subsection (3)(e) of this section or, for treatment and/or storage-only
CAMUs, the design standards at subsection (4) of this section.
(6) The department must provide public notice
and a reasonable opportunity for public comment before designating a CAMU. Such
a notice will include the rationale for any proposed adjustments under
subsection (3)(d)(v) of this section to the treatment standards in subsection
(3)(d)(iv) of this section.
(7)
Notwithstanding any other provision of this subsection, the department may
impose additional requirements as necessary to protect human health and the
environment.
(8) Incorporation of
the designation of and requirements for a CAMU into a existing permit must be
approved by the department according to the procedures for agency initiated
permit modifications under WAC
173-303-830(3),
or according to the permit modification procedures of WAC
173-303-830(4).
Statutory Authority:
Chapters
70.105 and
70.105D RCW. 09-14-105 (Order
07-12), § 173-303-64660, filed 6/30/09, effective 7/31/09. Statutory
Authority:
Chapters
70.105,
70.105D, and
15.54 RCW and
RCW
70.105.007. 04-24-065 (Order 03-10), §
173-303-64660, filed 11/30/04, effective
1/1/05.