Current through Register Vol. 48, No. 9, September 27, 2024
(a) Drip pads must
(1) Be constructed of nonearthen materials,
excluding wood and nonstructurally supported asphalt;
(2) 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;
(3) Have a curb or berm around the
perimeter;
(4)
(i) Have a hydraulic conductivity of less
than or equal to 1x10-7 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
1x10-7 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 264.572(b) instead of 264.572(a). (revised
12/93; 12/94)
(ii) 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 paragraph (b) of this Section.
(5) Be of sufficient structural strength and
thickness to prevent failure due to physical contact, climatic conditions, the
stress of daily operations, e.g., variable and moving loads such as vehicle
traffic, movement of wood, etc.
[Note: 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 paragraph.]
(b) If an owner/operator elects to comply
with 264.572(a) instead of 264.572(b), the drip pad must have:
(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:
(i) 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);
(ii) 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
(iii)
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:
(i) Constructed of materials that are:
(A) Chemically resistant to the waste managed
in the drip pad and the leakage that might be generated; and
(B) Of sufficient strength and thickness to
prevent collapse under the pressures exerted by overlaying materials and by any
equipment used at the drip pad;
(ii) Designed and operated to function
without clogging through the scheduled closure of the drip pad; and
(iii) 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.
Note: See 264.573(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 runoff.
(e) Unless protected by a structure, as
described in 264.570(b), the owner or operator must design, construct, operate
and maintain a runon 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 runoff that might enter
the system.
(f) Unless protected by
a structure or cover as described in 264.570(b), 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 24-hour, 25-year
storm.
(g) The drip pad must be
evaluated to determine that it meets the requirements of paragraphs (a) through
(f) of this section and the owner or operator must obtain a statement from
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 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 hazardous as per R.69-79.262.11 and, if so, must manage them under parts
261-268, 270, and section3010 of RCRA.
(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 pad following treatment in accordance with this requirement.
(l) Collection and holding units associated
with runon 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:
(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:
(i) Enter a record of the discovery in the
facility operating log;
(ii)
Immediately remove the portion of the drip pad affected by the condition from
service;
(iii) 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;
(iv) Within 24 hours after discovery of the
condition, notify the Department of the condition and, within 10 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.
(2) 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.
(3) 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 paragraph (m)(1)(iv) of this
section.
(n) Should a
permit under these regulations 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.
