Current through Register Vol. 48, No. 38, September 20, 2024
a) Drip pads must fulfill the following
requirements:
1) It must not be constructed
of earthen materials, wood, or asphalt, unless the asphalt is structurally
supported;
2) It must 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) It must have a curb or berm around the
perimeter;
4) In addition, the drip
pad must fulfill the following requirements:
A) It must have a hydraulic conductivity of
less than or equal to 1 x 10-7 centimeters per
second, 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
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 the existing drip pads and those drip pads for which the owner or
operator elects to comply with Section
725.542(b)
instead of Section
725.542(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) It must 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 (a), the Agency should generally consider applicable
standards established by professional organizations generally recognized by the
industry, including ACI 318-83 (Building Code Requirements for Reinforced
Concrete) or ASTM C 94-90 (Standard Specification for Ready-Mixed Concrete),
incorporated by reference in 35 Ill. Adm. Code
720.111(a).
b) If an owner or operator elects
to comply with Section
725.542(a)
instead of Section
725.542(b),
the drip pad must have the following features:
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 be constructed as follows:
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 be constructed as follows:
A) It must be constructed of materials that
fulfill the following requirements:
i) They
are chemically resistant to the waste managed in the drip pad and the leakage
that might be generated; and
ii)
They are 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
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.
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
725.540(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
725.540(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 pad surface must be cleaned thoroughly at least once every seven days
using an appropriate and effective cleaning technique, including but not
limited to, rinsing, washing with detergents or other appropriate solvents, or
steam cleaning, with residues being properly managed, such that accumulated
residues of hazardous waste or other materials are removed 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, in the facility's operating log, the
date and time of each cleaning and the cleaning procedure.
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, 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:
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 perform the
following acts:
A) It must enter a record of
the discovery in the facility operating log;
B) It must immediately remove from service
the portion of the drip pad affected by the condition;
C) It must 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, the owner or operator must 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: review the information
submitted; make a determination regarding whether the pad must be removed from
service completely or partially until repairs and clean up 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 clean up have been completed
according to the written plan submitted in accordance with subsection
(m)(1)(D).
n) 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.
