Current through Register Vol. 24-06, March 15, 2024
(1) Applicability. This section applies to
owners and operators of facilities that monofill special incinerator ash,
except as WAC
173-306-400 provides
otherwise.
(2) Minimum standards
for performance.
(a) Groundwater. Monofill
owners or operators may not contaminate underlying groundwater beyond the point
of compliance. Contamination and point of compliance are defined in WAC
173-306-100.
(b) Soil. Soils at the property boundary may
not exceed the following limits for cadmium due to the facility operations
based upon annual samples:
(i) The annual
increase in cadmium loading in the upper six inches of soil with a pH equal to
or greater than 6.5 may not exceed 0.5 kilograms per hectacre annually or a
total accumulation of 20 kilograms per hectacre; and
(ii) The annual increase in cadmium loading
in the upper six inches of soil with a pH less than 6.5 may not exceed a total
accumulation of 5.0 kilograms per hectacre.
(c) Air quality. Monofill owners or operators
may not cause a violation of an emission standard from any emission of
particulates, dusts or gases associated with the operation and/or
closure/post-closure of the landfill nor any ambient air quality standard at
the property boundary including the following ambient lead standard:
The level of lead and its compounds measured as elemental lead
in suspended particulate matter measured during a twenty-four hour sample taken
at the downwind facility boundary may not exceed 1.5 micrograms per cubic meter
of air due to the facility's operation or the latest national ambient air
quality standards. The sampling frequency will be monthly unless otherwise
approved by the department.
(d) Surface waters. Monofill owners or
operators may not cause a violation of any receiving water quality standard or
violate chapter 90.48
RCW from discharges of surface runoff, leachate, or any other liquid associated
with a monofill.
(3)
Siting standards. Monofill owners or operators receiving special incinerator
ash shall comply with incinerator ash siting standards of WAC
173-306-350(2).
(4) Minimum design standards.
(a) Minimizing liquids. Monofill owners or
operators shall minimize liquids admitted to active areas by:
(i) Covering according to subsection (5)(e)
of this section.
(ii) Disposing of
no ash containing free liquids unless approved by the department;
(iii) Designing, constructing, and
maintaining runoff controls to restrict the chance of a runoff event from
releasing contaminated runoff waters to an annual probability of one percent or
less (one hundred-year event or greater). In meeting this requirement the
following items are to be considered:
(A) The
design of the containment structures should be selected based on the ability of
the facility to store, test, and/or treat the runoff during a twenty-four hour
or longer storm event.
(B) The
design assumes that the storm event occurs during the final year of the active
life of the monofill or at a time when the facility is most vulnerable to a
storm that could produce the release of contaminated waters. The method of
placement of the ash should be considered when determining the volume available
for storage of runoff.
(C) A
minimum of one foot of freeboard (measured from the invert of the emergency
spillway) should be maintained following the occurrence of the design
storm.
(D) An emergency spillway is
to be constructed for the containment structure to provide controlled release
of excess runoff waters in the case where the design storm is
exceeded.
(iv) Design,
construct, and maintain diversion channels, channel containment berms,
culverts, pipes, and other drainage control features to pass and/or store
run-on to restrict the chance of failure of the drainage control features to an
annual probability of one percent or less (one hundred-year event or greater).
In meeting this requirement the following items are to be considered:
(A) For those cases where the run-on waters
are to be stored and/or treated, selection of the storm design should be based
on the appropriate procedures governing runoff controls.
(B) For those cases where the run-on waters
are to be diverted around the facility, the drainage control features should be
sized to pass the run-on peak discharge (design flood) of a magnitude that has
an annual exceedance probability of one percent or less (one hundred-year flood
peak discharge or greater).
(C)
Sufficient erosion protection and freeboard (one foot minimum) are to be
provided for all drainage control features to preclude failure of those
features during passage of the design flood.
(v) Submit engineering plans and
specifications for any containment barrier equalling or exceeding as storage
capacity of ten acre-feet to the department's dam safety section for review
under RCW
90.03.350.
(b) Leachate systems. Monofill owners or
operators shall:
(i) Install a
department-approved leachate collection system sized according to water balance
calculations or using other accepted engineering methods;
(ii) Install a leachate collection system to
prevent no more than one foot of leachate developing at the topographical low
point of the active area; and
(iii)
Install a leachate treatment system to meet requirements of WAC
173-306-200(3)(c)(ii)(B) through
(E).
(c) Liner and final cap design. Ash monofill
owners or operators shall comply with the requirements of WAC
173-306-450.
(d) Liner construction and inspection. Ash
monofill owners or operators shall:
(i) Comply
with the requirements of WAC
173-306-450.
(ii) Employ an independent third party as
defined in WAC
173-306-100 to inspect the liners
during construction and installation for uniformity, damage and imperfections
(e.g., holes, cracks, thin spots, foreign materials) and quality of
construction; and immediately after construction and installations to inspect:
(A) Synthetic liners and covers for tight
seams and joints and the absence of tears, punctures or blisters; and
(B) Soil-based and admixed liners and covers
for imperfections (e.g., lenses, cracks, channels, root holes) or structural
nonuniformities that may affect liner permeability.
(e) Filling requirements for ash
cells. Monofill owners or operators shall design and fill ash monofills in
phases or cells, as defined in WAC
173-306-100. Only one cell may be
open and in use at one time; each cell must be graded and covered with a
flexible high density polyethylene liner or other material of equivalent
mechanical strength and chemical resistance during the interim period before
reaching final elevation. The liner must be 60 mils and have the ability to
withstand weather conditions. The owner or operator shall provide, as part of
the interim cover, a method of detecting and/or monitoring/inspecting the
integrity and any possible failure of the interim cover.
(f) Fugitive dust controls. Monofill owners
and operators shall:
(i) Employ tire washing
for all ash-carrying vehicles as they leave the site or any equivalent method
to prevent the trackout of ash onto the site and the public right of way.
Contaminated wash-waters must be disposed of according to WAC
173-306-200(3)(c);
(ii) Orient the major axis of the active area
of the monofill with respect to the prevailing wind directions so as to
minimize the effect of wind upon dispersion of special incinerator ash unless
engineering designs can provide equivalent protection; and
(iii) Provide for paved approach and exit
roads outside the active area with traffic separation and traffic control
on-site and at the site entrance.
(g) Other design requirements. Monofill
owners and operators shall:
(i) Post signs at
each entrance to the active portion and at other locations, in sufficient
numbers to be seen from any approach to the active portion. Signs must bear the
legend "Danger - unauthorized personnel keep out" or an equivalent legend, and
must be legible from a distance of twenty-five feet;
(ii) Have either:
(A) A twenty-four-hour surveillance system
which continuously monitors and controls entry onto the active portion of the
facility; or
(B) An artificial or
natural barrier; or
(C) A
combination of both, which completely surrounds the active portion of the
facility, with a means to control access through gates or other entrances to
the active portion of the facility at all times.
(iii) Provide for monitoring according to WAC
173-306-500 using a design
approved by the department;
(iv)
Weigh all incoming ash on scales or provide an equivalent method of measuring
ash tonnage;
(v) Provide for
employee facilities including shelter, toilets, handwashing facilities, and
potable drinking water;
(vi)
Provide for unloading areas to be as small as possible, consistent with traffic
patterns and safe operation; and
(vii) Provide communication (such as
telephones) between employees working at the monofill and on-site or offsite
management offices to handle emergencies.
(5) Standards for operation and maintenance.
All owners and operators shall:
(a) Prohibit
the co-disposal of any other solid or hazardous waste in a special incinerator
ash landfill;
(b) Comply with the
requirements of the general operation standards, WAC
173-306-405;
(c) Control fugitive dust by wetting, by the
use of dust suppressing substances, covering, compacting, or otherwise managing
the active area of the monofill to control wind dispersal and prevent visible
emissions of windblown dust. Road dust on unpaved roads must also be similarly
controlled.
(d) Clearly mark the
active area boundaries authorized in the permit, with permanent posts or using
an equivalent method clearly visible for inspection purposes.
(e) Compact and cover ash daily before adding
successive layers according to the requirements of WAC
173-306-450.
(f) Maintain the monitoring systems required
in subsection (4)(g)(iii) of this section;
(g) Inspect the monofill weekly while it is
in operation and after major storms to detect evidence of any of the following:
(i) Deterioration, malfunctions, or improper
operation of run-on and runoff control systems and interim cover;
(ii) The presence of liquids in leak
detection systems, where installed, to comply with subsection (4)(b) of this
section. The department must be notified of any leaks into the leak detection
system within seven days after detecting the leak and immediately remove any
accumulated liquid. Notification shall include a schedule for determining the
cause of the leak and any remedial measures or increased groundwater monitoring
to assure that the performance standards of subsection (2)(a) of this section
are met;
(iii) The presence of
leachate in, and proper functioning of, leachate collection and removal
systems; and
(iv) Proper
functioning of engineered wind dispersal control systems.
(h) Record the inspections in the log as
required in WAC
173-306-405(6).
(6) Closure and post-closure
requirements.
(a) At final closure of the
monofill or upon closure of any cell, the owner or operator shall cover the
monofill or cell with a final cover designed and constructed according to
subsection (4)(d) of this section and shall comply with all closure
requirements of WAC
173-306-410;
(b) After final closure, the owner or
operator must comply with all post-closure requirements of WAC
173-306-410, and must:
(i) Maintain the integrity and effectiveness
of the final cover, including making repairs to the cap as necessary to correct
the effects of settling, subsidence, erosion, or other events;
(ii) Prevent run-on and runoff from eroding
or otherwise damaging the final cover;
(iii) Maintain and monitor the leak detection
system in accordance with subsection (4)(b) of this section, where such a
system is present; the owner or operator shall immediately remove any
accumulated liquid and notify the department of any leaks into the leak
detection system within seven days after detecting the leak. Notification shall
include a schedule for determining the cause of the leak and any remedial
measures or increased groundwater monitoring to assure that the performance
standards of subsection (2)(a) of this section are met;
(iv) Operate the leachate collection and
removal system; and
(v) Maintain
and operate the monitoring systems of WAC
173-306-500.
Statutory Authority:
Chapter
70.138 RCW. 00-19-018
(Order 00-17), § 173-306-440, filed 9/8/00, effective 10/9/00; 90-10-047,
§ 173-306-440, filed 4/30/90, effective
5/31/90.