Current through Register Vol. 47, No. 17, September 10, 2024
(a)
Drip pads must:
(1) Be constructed of
non-earthen materials, excluding wood and non-structurally 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).
(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 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 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 installation, and 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 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 possible
tune.
(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 run-off.
(e) Unless protected by a structure, as
described in § 264.570(b) of this subpart, 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-off that might enter the system.
(f) Unless protected by a structure or cover,
as described in § 264.570(b) of this subpart, 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 paragraphs (a) through
(f) of this section 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 hazardous as per
6 CCR
1007-3§ 262.11 and, if so, must manage them
under Parts 261-268, and Parts 99 and 100.
(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 the 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 following treatment in accordance with this
requirement.
(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 may cause, 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 cause, 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 the discovery of
the condition, notify the Director of the condition and, within 10 working
days, provide written notice to the Director 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 Director will 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 Director 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 paragraph (m)(1)(iv)
of this section.
(n)
Should a permit be necessary, the Director will specify in the permit all
design and operating practices 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.
