Current through Register Vol. 24-06, March 15, 2024
(1) Applicability.
(a) The requirements of this section apply to
owners and operators of facilities that use new or existing drip pads to convey
treated wood drippage, precipitation, and/or surface water runoff to an
associated collection system. Existing drip pads are those constructed before
December 6, 1990, and those for which the owner or operator has a design and
has entered into binding financial or other agreements for construction prior
to December 6, 1990. All other drip pads are new drip pads. The requirement in
subsection (4)(b)(iii) of this section to install a leak collection system
applies only to those drip pads that are constructed after December 24, 1992,
except for those constructed after December 24, 1992, for which the owner or
operator has a design and has entered into binding financial or other
agreements for construction prior to December 24, 1992.
(b) The owner or operator of any drip pad
that is inside or under a structure that provides protection from precipitation
so that neither runoff nor run-on is generated is not subject to regulation
under subsection (4)(e) or (f) of this section, as appropriate.
(c) The requirements of this section are not
applicable to the management of infrequent and incidental drippage in storage
yards provided that: The owner or operator maintains and complies with a
written contingency plan that describes how the owner or operator will respond
immediately to the discharge of such infrequent and incidental drippage. At a
minimum, the contingency plan must describe how the owner or operator will do
the following:
(i) Clean up the
drippage;
(ii) Document the cleanup
of the drippage;
(iii) Retain
documents regarding cleanup for three years; and
(iv) Manage the contaminated media in a
manner consistent with federal regulations.
(2) Assessment of existing drip pad
integrity.
(a) For each existing drip pad as
defined in subsection (1) of this section, the owner or operator must evaluate
the drip pad and determine that it meets all of the requirements of this
section, except the requirements for liners and leak detection systems of
subsection (4)(b) of this section. No later than the effective date of this
rule, the owner or operator must obtain and keep on file at the facility a
written assessment of the drip pad, reviewed and certified by an independent,
qualified registered professional engineer that attests to the results of the
evaluation. The assessment must be reviewed, updated and recertified annually
until all upgrades, repairs, or modifications necessary to achieve compliance
with all of the standards of subsection (4) of this section are complete. The
evaluation must document the extent to which the drip pad meets each of the
design and operating standards of subsection (4) of this section, except the
standards for liners and leak detection systems, specified in subsection (4)(b)
of this section.
(b) The owner or
operator must develop a written plan for upgrading, repairing, and modifying
the drip pad to meet the requirements of subsection (4)(b) of this section, and
submit the plan to the department no later than two years before the date that
all repairs, upgrades, and modifications are complete. This written plan must
describe all changes to be made to the drip pad in sufficient detail to
document compliance with all the requirements of subsection (4) of this
section. The plan must be reviewed and certified by an independent qualified
registered professional engineer.
(c) Upon completion of all upgrades, repairs,
and modifications, the owner or operator must submit to the department, the
as-built drawings for the drip pad together with a certification by an
independent qualified registered professional engineer attesting that the drip
pad conforms to the drawings.
(d)
If the drip pad is found to be leaking or unfit for use, the owner or operator
must comply with the provisions of subsection (4)(m) of this section or close
the drip pad in accordance with subsection (6) of this section.
(3) Design and installation of new
drip pads.
Owners and operators of new drip pads must ensure that the pads
are designed, installed, and operated in accordance with one of the
following:
(a) All of the requirements
of subsections (4) of this section (except subsection (4)(a)(iv)), (5) and (6)
of this section; or
(b) All of the
requirements of subsections (4) of this section (except subsection (4)(b)), (5)
and (6) of this section.
(4) Design and operating requirements.
(a) Drip pads must:
(i) Be constructed of nonearthen materials,
excluding wood and nonstructurally supported asphalt;
(ii) Be sloped to free-drain treated wood
drippage, rain and other waters, or solutions of drippage and water or other
wastes to the associated collection system;
(iii) Have a curb or berm around the
perimeter;
(iv)
(A) Have a hydraulic conductivity of less
than or equal to 1 x 10-7 centimeters per second,
for example, existing concrete drip pads must be sealed, coated, or covered
with a surface material with a hydraulic conductivity of less than or equal to
1 x 10-7 centimeters per second such that the entire
surface where drippage occurs or may run across is capable of containing such
drippage and mixtures of drippage and precipitation, materials, or other wastes
while being routed to an associated collection system. This surface material
must be maintained free of cracks and gaps that could adversely affect its
hydraulic conductivity, and the material must be chemically compatible with the
preservatives that contact the drip pad. The requirements of this provision
apply only to existing drip pads and those drip pads for which the owner or
operator elects to comply with subsection (3)(b) of this section instead of
subsection (3)(a) of this section.
(B) The owner or operator must obtain and
keep on file at the facility a written assessment of the drip pad, reviewed and
certified by an independent, qualified registered professional engineer that
attests to the results of the evaluation. The assessment must be reviewed,
updated and recertified annually. The evaluation must document the extent to
which the drip pad meets the design and operating standards of this subsection,
except for (b) of this subsection.
(v) Be of sufficient structural strength and
thickness to prevent failure due to physical contact, climatic conditions,
stress of installation, the stress of daily operations, for example, variable
and moving loads such as vehicle traffic, movement of wood, etc.
Note:
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The department will generally consider applicable
standards established by professional organizations generally recognized by the
industry such as the American Concrete Institute (ACI) or the American Society
of Testing and Materials (ASTM) in judging the structural integrity requirement
of this subsection.
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(b) If an owner/operator elects to comply
with subsection (3)(a) of this section instead of subsection (3)(b) of this
section, the drip pad must have:
(i) A
synthetic liner installed below the drip pad that is designed, constructed, and
installed to prevent leakage from the drip pad into the adjacent subsurface
soil or groundwater or surface water at any time during the active life
(including the closure period) of the drip pad. The liner must be constructed
of materials that will prevent waste from being absorbed into the liner and to
prevent releases 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 drip pad leakage to
which they are exposed, climatic conditions, the stress of installation, and
the stress of daily operation (including stresses from vehicular traffic on the
drip pad);
(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
that could come in contact with the waste or leakage; and
(ii) A leakage detection system immediately
above the liner that is designed, constructed, maintained and operated to
detect leakage from the drip pad. The leakage detection system must be:
(A) Constructed of materials that are:
(I) Chemically resistant to the waste managed
in the drip pad and the leakage that might be generated; and
(II) Of sufficient strength and thickness to
prevent collapse under the pressures exerted by overlaying materials and by any
equipment used at the drip pad;
(B) Designed and operated to function without
clogging through the scheduled closure of the drip pad; and
(C) Designed so that it will detect the
failure of the drip pad or the presence of a release of hazardous waste or
accumulated liquid at the earliest practicable time.
(iii) A leakage collection system immediately
above the liner that is designed, constructed, maintained and operated to
collect leakage from the drip pad such that it can be removed from below the
drip pad. The date, time, and quantity of any leakage collected in this system
and removed must be documented in the operating log.
(c) Drip pads must be maintained such that
they remain free of cracks, gaps, corrosion, or other deterioration that could
cause hazardous waste to be released from the drip pad.
Note:
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See subsection (4)(m) of this section for remedial
action required if deterioration or leakage is detected.
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(d)
The drip pad and associated collection system must be designed and operated to
convey, drain, and collect liquid resulting from drippage or precipitation in
order to prevent runoff.
(e) Unless
protected by a structure, as described in subsection (1)(b) of this section,
the owner or operator must design, construct, operate and maintain a run-on
control system capable of preventing flow onto the drip pad during peak
discharge from at least a twenty-four-hour, twenty-five-year storm, unless the
system has sufficient excess capacity to contain any runoff that might enter
the system.
(f) Unless protected by
a structure or cover as described in subsection (1)(b) of this section, 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) The drip pad must be evaluated to
determine that it meets the requirements of (a) through (f) of this subsection
and the owner or operator must obtain a statement from an independent,
qualified registered professional engineer certifying that the drip pad design
meets the requirements of this section.
(h) Drippage and accumulated precipitation
must be removed from the associated collection system as necessary to prevent
overflow onto the drip pad.
(i) The
drip pad surface must be cleaned thoroughly in a manner and frequency such that
accumulated residues of hazardous waste or other materials are removed, with
residues being properly managed as hazardous waste, so as to allow weekly
inspections of the entire drip pad surface without interference or hindrance
from accumulated residues of hazardous waste or other materials on the drip
pad. The owner or operator must document the date and time of each cleaning and
the cleaning procedure used in the facility's operating log. The owner/operator
must determine if the residues are dangerous under WAC
173-303-070 and, if so, must
manage them under this chapter.
(j)
Drip pads must be operated and maintained in a manner to minimize tracking of
hazardous waste or hazardous waste constituents off the drip pad as a result of
activities by personnel or equipment.
(k) After being removed from the treatment
vessel, treated wood from pressure and nonpressure processes must be held on
the drip pad until drippage has ceased. The owner or operator must maintain
records sufficient to document that all treated wood is held on the drip pad
following treatment in accordance with this requirement.
(l) Collection and holding units associated
with run-on and runoff control systems must be emptied or otherwise managed as
soon as possible after storms to maintain design capacity of the
system.
(m) Throughout the active
life of the drip pad and as specified in the permit, if the owner or operator
detects a condition that may have caused or has caused a release of hazardous
waste, the condition must be repaired within a reasonably prompt period of time
following discovery, in accordance with the following procedures:
(i) Upon detection of a condition that may
have caused or has caused a release of hazardous waste (e.g., upon detection of
leakage in the leak detection system), the owner or operator must:
(A) Enter a record of the discovery in the
facility operating log;
(B)
Immediately remove the portion of the drip pad affected by the condition from
service;
(C) Determine what steps
must be taken to repair the drip pad and clean up any leakage from below the
drip pad, and establish a schedule for accomplishing the repairs;
(D) Within twenty-four hours after discovery
of the condition, notify the department of the condition and, within ten
working days, provide written notice to the department with a description of
the steps that will be taken to repair the drip pad and clean up any leakage,
and the schedule for accomplishing this work.
(ii) The department will review the
information submitted, make a determination regarding whether the pad must be
removed from service completely or partially until repairs and cleanup are
complete and notify the owner or operator of the determination and the
underlying rationale in writing.
(iii) Upon completing all repairs and
cleanup, the owner or operator must notify the department in writing and
provide a certification signed by an independent, qualified registered
professional engineer, that the repairs and cleanup have been completed
according to the written plan submitted in accordance with (m)(i)(D) of this
subsection.
(n) Should a
permit be necessary, 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.
(o) The
owner or operator must maintain, as part of the facility operating log,
documentation of past operating and waste handling practices. This must include
identification of preservative formulations used in the past, a description of
drippage management practices, and a description of treated wood storage and
handling practices.
(5)
Inspections.
(a) During construction or
installation, liners and cover systems (e.g., membranes, sheets, or coatings)
must be inspected for uniformity, damage and imperfections (e.g., holes,
cracks, thin spots, or foreign materials). Immediately after construction or
installation, liners must be inspected and certified as meeting the
requirements of subsection (4) of this section by an independent qualified,
registered professional engineer. This certification must be maintained at the
facility as part of the facility operating record. After installation, liners
and covers must be inspected to ensure tight seams and joints and the absence
of tears, punctures, or blisters.
(b) While a drip pad 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) The presence of leakage in and proper
functioning of leak detection system;
(iii) Deterioration or cracking of the drip
pad surface.
Note:
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See subsection (4)(m) of this section for remedial
action required if deterioration or leakage is detected.
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(6) Closure.
(a) At closure, the owner or operator must
remove or decontaminate all waste residues, contaminated containment system
components (pad, liners, etc.), contaminated subsoils, and structures and
equipment contaminated with waste and leakage, and manage them as hazardous
waste.
(b) If, after removing or
decontaminating all residues and making all reasonable efforts to effect
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, he must close the facility and perform post-closure care in
accordance with closure and post-closure care requirements that apply to
landfills (WAC
173-303-665(6)
). For permitted units, the requirement to have a permit continues throughout
the post-closure period. In addition, for the purpose of closure, post-closure,
and financial responsibility, such a drip pad is then considered to be
landfill, and the owner or operator must meet all of the requirements for
landfills specified in WAC
173-303-610 and
173-303-620.
(c)
(i) The
owner or operator of an existing drip pad, as defined in subsection (1) of this
section, that does not comply with the liner requirements of subsection
(4)(b)(i) of this section must:
(A) Include in
the closure plan for the drip pad 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
173-303-610 and
173-303-620 for closure and
post-closure care of a drip pad subject to this subsection 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.
Statutory Authority:
Chapters
70.105 and
70.105D RCW. 09-14-105 (Order
07-12), § 173-303-675, filed 6/30/09, effective 7/31/09; 98-03-018 (Order
97-03), § 173-303-675, filed 1/12/98, effective 2/12/98; 95-22-008 (Order
94-30), § 173-303-675, filed 10/19/95, effective
11/19/95.