a) Drip pads must fulfill the following:
1) Not be constructed of non-earthen
materials, wood, or asphalt, unless the asphalt is structurally
supported;
2) Be sloped to
free-drain to the associated collection system treated wood drippage, rain,
other waters, or solutions of drippage and water or other wastes;
3) Have a curb or berm around the
perimeter;
4) In addition, the drip
pad must fulfill the following:
A) Have a
hydraulic conductivity of less than or equal to
1x10
-7 centimeters per second (cm/sec), e.g.,
existing concrete drip pads must be sealed, coated, or covered with a surface
material with a hydraulic conductivity of less than or equal to
1x10
-7 cm/sec 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 the existing drip pads and those drip pads for which the owner or
operator elects to comply with Section
724.672(b)
instead of Section
724.672(a).
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 a qualified 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 Section, except for in subsection
(b).
5) Be of sufficient
structural strength and thickness to prevent failure due to physical contact,
climatic conditions, the stress of installation, and the stress of daily
operations, e.g., variable and moving loads such as vehicle traffic, movement
of wood, etc.
BOARD NOTE: In judging the structural integrity requirement
of this subsection (c), the Agency should generally consider applicable
standards established by professional organizations generally recognized by the
industry, including ACI 318 (Building Code Requirements for Reinforced
Concrete), or ASTM C 94-90 (Standard Specification for Ready-Mixed Concrete),
each incorporated by reference in 35 Ill. Adm. Code
720.111(a).
b) If an owner or
operator elects to comply with Section
724.672(a)
instead of Section
724.672(b),
the drip pad must have the following:
1) 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 fulfill the
following:
A) It must be 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) It must be 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) It must be installed to cover all
surrounding earth that could come in contact with the waste or leakage;
and
2) 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 fulfill the following:
A) It must be constructed of materials that
are as follows:
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; and
B) It must be designed and operated to
function without clogging through the scheduled closure of the drip pad;
and
C) It must be 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.
3) A leaking
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.
A) 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 to allow weekly inspections of the entire drip pad surface without
interference of 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 cleaning procedure used in the facility's operating
log. The owner or operator must determine if the residues are hazardous, as per
35 Ill. Adm. Code
722.111,
and, if so, the owner or operator must manage them under 35 Ill. Adm. Code
721
through
728, and section 3010 of RCRA (
42 USC
6930
).
B) The federal rules do not
contain a
40 CFR
264.573(b)(3)(B). This
subsection (b) is added to conform to Illinois Administrative Code
rules.
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.
BOARD NOTE: See subsection (m) for remedial action required
if deterioration or leakage is detected.
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 run-off.
e) Unless the drip pad is protected by a
structure, as described in Section
724.670(b),
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 24-hour, 25-year storm, unless the system has
sufficient excess capacity to contain any run-on that might enter the
system.
f) Unless the drip pad is
protected by a structure or cover, as described in Section
724.670(b),
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, 25-year storm.
g)
The drip pad must be evaluated to determine that it meets the requirements of
subsections (a) through (f). The owner or operator must obtain a statement from
a qualified 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 surface must be cleaned
thoroughly at least once every seven days such that accumulated residues of
hazardous waste or other materials are removed, using an appropriate and
effective cleaning technique, including but not limited to, rinsing, washing
with detergents or other appropriate solvents, or steam cleaning. The owner or
operator must document, in the facility's operating log, the date and time of
each cleaning and the cleaning procedure used.
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 non-pressure
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 pad, in accordance with this Section, following
treatment.
l) Collection and
holding units associated with run-on and run-off 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 could lead to 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:
1) 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
do the following:
A) Enter a record of the
discovery in the facility operating log;
B) Immediately remove from service the
portion of the drip pad affected by the condition;
C) Determine what steps must be taken to
repair the drip pad, clean up any leakage from below the drip pad, and
establish a schedule for accomplishing the clean up and repairs;
D) Within 24 hours after discovery of the
condition, notify the Agency of the condition and, within 10 working days,
provide written notice to the Agency 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.
2) The Agency must do the following: 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.
3)
Upon completing all repairs and clean up, the owner or operator must notify the
Agency 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
subsection (m)(1)(D).
n)
If a permit is necessary, the Agency must 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.