container could range from a spring-operated safety container to a drum
with its opening covered by a piece of plywood. EPA stated in the
proposal that generators would not need to seal, secure, latch, or
close the container every time a solvent-contaminated wipe is placed
inside the container; rather, they would only need to ensure that the
container was covered. EPA also proposed that solvent-contaminated
wipes must be transported in containers that are designed, constructed,
and managed to minimize loss to the environment. EPA explained this to
mean that the containers must not leak liquids and must control
emission releases to the air. The Agency stated it would consider
containers that met the Department of Transportation (DOT) packaging
requirements for hazardous materials to meet the proposed performance
standard, as would closed, sealed, impermeable containers. Finally, EPA
proposed that handling facilities, such as laundries and combustors,
must contain solvent-contaminated wipes in containers that met the
transportation container standard or containers that met the generator
container standard.
    EPA also requested comment on requiring the transportation of wipes
in impermeable ``closed'' containers. In this context, closed
containers were defined as containers with a lid that screws on to the
top and must be sealed to be considered closed. EPA also requested
comment on whether or not EPA should defer to the U.S. Department of
Labor's Occupational Safety and Health Administration (OSHA)
regulations for the management of solvent-contaminated wipes during
accumulation at the generator's facility. In addition, for reusable
wipes, EPA sought comment on adding a provision that allows wipes
containing less than five grams of solvent to be transported without
any management standards and on whether cloth bags have the ability to
meet the proposed performance standard of minimizing loss to the
environment.
Comments: Containers
    Over half of the commenters supported the covered standard for
containers and agreed with a performance-based standard, which allows
companies flexibility in meeting the standard. Many of these commenters
noted that the covered standard reflects current industry practice and
that this standard is adequate to control fugitive air emissions and
potential risk of fire. These commenters stated that many businesses
use large quantities of solvent-contaminated wipes each day, so to
unseal and seal a container every time a wipe is placed inside it would
be overly burdensome. Other commenters supported the performance-based
standard because they feared a specific container standard (e.g., a 55-
gallon drum) could force laundries to purchase new vehicles in order to
transport the required containers. Commenters also argued that EPA
regulations should be consistent with DOT and OSHA standards for
covered containers.
    The remaining commenters opposed the covered standard, arguing it
would not sufficiently protect human health and the environment. These
commenters disagreed with EPA's assertion that containers covered with
plywood or cardboard would be sufficient to prevent air emissions or
prevent spills during accumulation and transportation. These commenters
also opposed the use of cloth and woven polypropylene bags to store
solvent-contaminated wipes because these bags are permeable and thus,
would not prevent releases of free liquid spent solvent. They urged EPA
to strengthen the container standard by requiring a performance-based
``closed'' container standard and requiring the use of impermeable
bags. These commenters also called for one consistent container
standard throughout the handling process, because there was no reason
for having different standards for on-site accumulation,
transportation, and handling.
EPA Response: Containers
    EPA agrees with those commenters who argued that a strengthened
container standard is necessary to protect human health and the
environment. In the proposal, EPA explained that plywood over a
container would meet the covered container standard; however, EPA
acknowledges that this scenario would not always prevent releases,
especially if the container was accidentally overturned. Therefore, EPA
is not finalizing the proposed covered container standard and is
instead requiring that solvent-contaminated wipes be accumulated,
stored, and transported in non-leaking, closed containers, such as
containers with a spring-loaded lid or an impermeable bag. Today's
standard addresses commenters' concerns regarding spills and exposures
to solvents in a covered container (e.g., simply covering a container
with plywood would not meet today's container standard and cloth bags,
if used, would have to be non-leaking).
    Regarding the closed container standard, EPA agrees with those
commenters that argued that it is burdensome to unseal and seal a
container every time a wipe is placed in the container. Therefore,
today's closed container standard is defined to allow for flexibility
during accumulation of solvent-contaminated wipes; during accumulation,
a closed container does not need to be sealed and is considered closed
when there is complete contact between the fitted lid and the rim,

except when it is necessary to add or remove solvent-contaminated
wipes. Then, when the container is full, or when the solvent-
contaminated wipes are no longer being accumulated, or when the
container is being transported, the container must be sealed with all
lids properly and securely affixed to the container and all openings
tightly bound or closed sufficiently to prevent leaks and emissions.
    Today's closed container standard more adequately addresses
fugitive air emissions from the solvent-contaminated wipes than the
proposed covered container standard and thus, will adequately protect
facility employees, inspectors, emergency response personnel,
transporters, and other downstream handlers. Moreover, EPA's non-
leaking, closed container standard remains a performance-based
standard, which many commenters supported because it provides
generators the flexibility to meet the standard in a way that best
suits their business without increasing compliance costs. Today's
container standard should not be overly burdensome since several trade
associations and laundries already encourage their members and
customers to use closed or sealed containers during storage and
transportation of solvent-contaminated wipes.
    EPA also agrees with those commenters that argued that
substantively different container standards for solvent-contaminated
wipes during accumulation, transportation, and handling are not
necessary. Today's container standard applies to solvent-contaminated
wipes under both conditional exclusions and applies to accumulation and
storage at the generating facility, transportation either on-site or
off-site, and, finally, storage and management at the handling
facility. This represents a simple and straightforward approach that
eases implementation and compliance monitoring. Additionally, this
condition replaces the proposed management condition for transporters
and handlers to manage solvent-contaminated wipes in containers
``designed, constructed, and managed to minimize loss to the
environment,'' which was subjective and thus, more difficult to
interpret than today's container standard.
    Furthermore, although today's rule does not impact how DOT or OSHA
regulations apply to solvent-contaminated wipes, EPA has determined
that it is not appropriate to rely solely on these regulations in lieu
of a container standard.

E. Accumulation Time Limit

    In the November 2003 proposal, EPA did not propose a time limit on
accumulation for disposable wipes. However, EPA did propose to apply
the speculative accumulation limits on reusable wipes consistent with
other conditional exclusions from the definition of solid waste for
recycling activities. The speculative accumulation provision requires
that, in any calendar year, 75 percent of the material accumulated for
recycling must actually be recycled. In addition, EPA requested comment
on whether specific time limits should be imposed for accumulation and
storage of both reusable and disposable wipes and specifically
requested comment on whether generators should follow the accumulation
time limits in 40 CFR 262.34 that are applicable for their generator
status (i.e., 90 days for large quantity generators and 180 days for
small quantity generators). If the accumulation time limits in 40 CFR
262.34 were included in the final rule, generators would have to mark
any container in which the solvent-contaminated wipes were being
accumulated with a label that included the date accumulation started.
Comments: Accumulation Time Limit
    The majority of commenters believed accumulation time limits for
solvent-contaminated wipes are unnecessary and unwarranted. These
commenters argued that because the wipes are no longer subject to
regulation as hazardous waste there was no need for an accumulation
time limit (and noted that EPA does not require accumulation limits on
other solid non-hazardous wastes). Other commenters indicated that
requiring transportation at 90 or 180 days would be burdensome for
facilities generating small quantities of solvent-contaminated wipes.
For reusable wipes, most commenters believed accumulation time limits
were unnecessary because the vast majority of generators have contracts
with laundries that stipulate weekly pickup of their solvent-
contaminated wipes.
    The remaining commenters suggested adopting an accumulation time
limit. These commenters argued that accumulation limits would decrease
the time solvent-contaminated wipes are managed on-site, thereby
decreasing the risk of adverse affects to human health, such as from
fires and volatilization. Furthermore, these commenters believed that
generators do not have an incentive to remove solvent-contaminated
wipes, and thus, specific accumulation time limits would be necessary
in order to prevent over accumulation of wipes at generator facilities.
    Several commenters supported applying the speculative accumulation
provision to reusable wipes. These commenters believed reusable wipes
should have the same management standards as other recycled hazardous
secondary materials that are excluded from regulation under 40 CFR
261.4(a).
EPA Response: Accumulation Time Limit
    EPA agrees with commenters that argued accumulation time limits for
solvent-contaminated wipes are necessary. During the accumulation
period, solvent-contaminated wipes may contain free liquids or free
liquids may occur, for example, from percolation or compression of
wipes in a container. Thus, in the absence of accumulation limits,
generators may have an incentive to store solvent-contaminated wipes
containing free liquids indefinitely in order to avoid potential
hazardous waste disposal costs of the free liquid spent solvent. This
accumulation time limit is appropriate because, although the solvent-
contaminated wipes are not hazardous wastes when managed under today's
exclusions, the free liquid spent solvent is subject to the applicable
hazardous waste regulations upon its removal from the wipe and/or the
container holding the wipe.
    EPA, therefore, agrees with commenters that supported an
accumulation time limit. An accumulation time limit ensures that free
liquid hazardous waste solvent is removed within an appropriate
timeframe. This condition also decreases the maximum amount of time
that solvent-contaminated wipes are managed on-site, which further
decreases the risk of adverse affects to human health, such as from
fires and volatilization. Therefore, in today's final rule, EPA is
establishing an accumulation time limit for both reusable and
disposable wipes which allows solvent-contaminated wipes to be
accumulated by the generator for up to 180 days prior to cleaning or
disposal. Today's accumulation standard is necessary to ensure the
proper disposition of the solvent-contaminated wipes and the free
liquids that may accumulate in containers.
    The regulations at 40 CFR 262.34 establish accumulation time limits
based on the quantity of hazardous waste generated; however, solvent-
contaminated wipes under today's exclusions are not hazardous wastes
and thus, do not count towards the

generator's status. Therefore, strict compliance with the hazardous
waste accumulation time limits presents an odd situation where a
generator could be generating large amounts of excluded solvent-
contaminated wipes, but only a small amount of other hazardous waste.
It would seem inappropriate to require an accumulation time limit for
solvent-contaminated wipes that are based on quantities of hazardous
waste that don't include the solvent-contaminated wipes.
    Furthermore, applying speculative accumulation limits, which is
consistent with how other hazardous secondary materials excluded from
the definition of solid waste are managed, is not appropriate. Solvent-
contaminated wipes may contain free liquids during accumulation and
applying speculative accumulation limits to today's exclusions would
have allowed generators to accumulate solvent-contaminated wipes, and
the associated free liquid spent solvent, for up to a year. This amount
of time would likely have increased the quantity of free liquid spent
solvent managed onsite and thus, may increase adverse affects to human
health, such as from fires and volatilization.
    To ensure solvent-contaminated wipes and any associated free liquid
spent solvent are managed appropriately, while at the same time
allowing the greatest flexibility and ease of compliance for
generators, EPA chose to establish a flat 180-day accumulation time
limit for all facilities generating solvent-contaminated wipes. This
straightforward accumulation time limit is easier to implement by the
tens of thousands of facilities that generate solvent-contaminated
wipes. The 180-day accumulation time limit is what is currently
required for small quantity generators under 40 CFR 262.34 and thus,
provides the greatest flexibility for generators managing excluded
solvent-contaminated wipes.\32\
---------------------------------------------------------------------------

    \32\ The regulations at 40 CFR 262.34 also allow small quantity
generators to accumulate hazardous wastes for up to 270 days if the
generator must transfer the waste to a facility located more than
200 miles from the generator. However, because solvent-contaminated
wipes managed under today's rule can go to municipal solid waste
landfills, we anticipate that transportation distances will be
shortened given the greater number of available options under
today's rule.
---------------------------------------------------------------------------

    We agree with commenters that reusable wipes are routinely picked
up by laundries on a periodic (e.g., weekly) basis and, thus, today's
accumulation time limit is not likely to impose an undue burden.
Additionally, disposable wipes meeting the conditions of today's rule
may be discarded with a facility's other solid waste trash, which is
likely collected on a frequent basis. We also note that the free
liquids, upon removal from the solvent-contaminated wipes or from the
container holding the wipes, are subject to the applicable hazardous
waste regulations, including accumulation time limits in 40 CFR 262.34.

F. Labeling

    In the November 2003 proposal, EPA proposed that containers
managing disposable wipes be labeled ``Exempt Solvent-Contaminated
Wipes'' to alert downstream handlers to the contents of the container
and ensure proper handling and/or inspection of the materials. EPA did
not propose a similar labeling condition for reusable wipes because
laundries and dry cleaners typically have agreements with their
customers and thus, already know what is in the container of wipes that
arrive. However, EPA requested comment on whether a labeling
requirement was necessary for reusable wipes containers.
Comments: Labeling
    Some commenters agreed with EPA that containers that hold
disposable wipes should be labeled. These commenters believed that
labeling was necessary in order to allow identification of the
containers' contents for emergency response personnel, motor carrier
inspectors, transporters, and downstream handlers. Other commenters
also believed that labeling is good business practice and that it would
not be burdensome to implement.
    On the other hand, other commenters were opposed to the labeling
requirement because it constituted an undue burden on generators. These
commenters also argued that the DOT labeling requirements would be
sufficient and that EPA should not create a duplicative label.
Furthermore, these commenters noted that since generators would have
contractual arrangements with any handling facility, the downstream
handlers would already know the contents of the containers. Some
commenters also argued that facilities generating both non-hazardous
wipes--that is wipes that are not used with listed hazardous waste and
do not exhibit characteristics of hazardous waste--and excluded
disposable wipes would need to separate the wipes in order to meet the
labeling condition, even though both types would be sent to, for
example, the same MSWLF.
    The majority of commenters, however, recommended the same labeling
requirement should apply to both disposable and reusable wipes. Most of
these commenters did not take a position on whether or not such a
requirement was necessary, but argued that, if a label was necessary,
then it should apply equally to both disposable and reusable wipes.
EPA Response: Labeling
    EPA agrees with the majority of commenters that the labeling
requirement should be applied to both disposable and reusable wipes.
Concerns regarding air emissions and potential fire risk apply to all
solvent-contaminated wipes regardless of their ultimate disposition.
Although DOT packaging requirements may apply, as appropriate, to the
transport of reusable and disposable wipes, it is important to require
labeling during accumulation, storage, and at the handling facility in
order to communicate the contents to facility employees, emergency
response personnel, downstream handlers, and state and EPA inspectors,
as well as transporters and motor carrier inspectors. Thus, in today's
rule, we are requiring that solvent-contaminated wipes must be managed
in containers labeled ``Excluded Solvent-Contaminated Wipes.''
Imposition of this condition addresses comments that urged EPA to adopt
the same labeling standard for both types of wipes in order to ease
implementation and understanding of the regulations, especially for
facilities that use both reusable and disposable wipes.
    The Agency does not believe that this condition places an undue
burden on facilities, as labels are relatively inexpensive and can be
affixed to containers with relative ease. Additionally, generators of
disposable wipes, which have generally been heretofore regulated as
hazardous wastes, have already had to comply with labeling requirements
under the hazardous waste regulations.

G. ``No Free Liquids'' and ``Dry'' Conditions

    In the November 2003 proposal, EPA proposed that reusable wipes
going to an industrial laundry or dry cleaner and disposable wipes
going to a combustor must have no free liquids when sent off-site. We
proposed defining ``no free liquids'' as allowing no liquid solvent to
drip from the wipe when sent off-site and no free liquids in the bottom
of the container in which the wipes are transported for cleaning or
disposal. EPA explained that generators could meet the ``no free
liquids'' condition by ensuring that a solvent-contaminated wipe held
for a short period of time, such as when being moved from one container
to another, does not drip. Facilities could use mechanical

wringers, solvent extraction technologies or process knowledge to meet
the standard. Screen-bottom drums could also be used to ensure no
liquid solvent was in the bottom of the container used to transport the
solvent-contaminated wipes for cleaning or disposal.
    For wipes going to a landfill, EPA proposed that the solvent-
contaminated wipes meet a ``dry'' condition. ``Dry'' was defined as a
wipe containing less than five grams of solvent. To meet the ``dry''
condition, generators could use a centrifuge or other solvent
extraction technologies, use less than five grams of solvent per wipe,
or use normal business records that indicate solvent usage rates, such
as the total amount of solvent used each month divided by the number of
wipes used each month. Generators could also conduct sampling to ensure
the solvent-contaminated wipes met the condition.
    EPA also requested comment on a ``no free liquids when wrung''
condition that would require that each wipe not drip solvent when hand
wrung.
Comments: No Free Liquids
    Many commenters supported the ``no free liquids'' condition for
solvent-contaminated wipes going to laundries/dry cleaners and
combustors. Some commenters noted that this is already standard
practice for solvent-contaminated wipes going to laundries and dry
cleaners and is used by many states in their regulations for reusable
wipes. Commenters believed that ensuring that the solvent-contaminated
wipes do not contain free liquids would prevent releases of solvents in
transportation to handling facilities.
    Most commenters urged EPA not to place a specific limit on the
maximum amount of solvent or the concentration of solvent on a wipe and
not to place a numerical limit on the number of shop towels laundries
or dry cleaners can accept on an annual basis. They asserted that a
limit on the number of solvent-contaminated wipes that can be sent for
cleaning would adversely impact the manufacturing process and would be
confusing and essentially impossible to implement. They also argued
that limits on the amount or concentration of solvent are unnecessary,
particularly because CWA/NPDES permits impose enforceable limits on
point source discharges to waterways from laundries and dry cleaners
through industrial user and pretreatment requirements.
    Some commenters suggested that EPA clarify the ``no free liquids''
condition and recommended that EPA specify permissible technologies
that are presumed to meet the ``no free liquids'' condition. Other
commenters disagreed that EPA should compile a list of acceptable
technologies. Moreover, some commenters urged EPA to finalize a
standard that is simple enough for hundreds of thousands of businesses
to apply daily and clear enough to avoid confusion during inspections
and enforcement.
    Many commenters did not support EPA's alternative condition of ``no
free liquids when wrung'' because requiring each solvent-contaminated
wipe to be wrung would unnecessarily expose employees to solvents.
Additionally, ``when wrung'' is too subjective a standard and creates
confusion (for example, ``when wrung'' is dependent on the size and
strength of the individual doing the wringing). Still other commenters
supported the ``when wrung'' alternative, arguing that the condition
would result in more solvent removed from the wipe.
EPA Response: No Free Liquids
    EPA agrees with commenters that supported the ``no free liquids''
condition, particularly because this is currently standard industry
practice and is used by many states in their programs, and thus, is
already familiar to the regulated community and state regulators. One
concern, however, is how to define and make the ``no free liquids''
condition an objective, clear, and enforceable standard. Some
commenters suggested defining a list of solvent extraction technologies
to meet this standard; however, it is not appropriate to require the
use of specific technologies, particularly if such specific
technologies are not necessary under certain circumstances to meet the
condition and may impose unnecessary cost on businesses. Furthermore,
technologies evolve over time and rulemaking would be required to
incorporate new technologies into the rule. To reduce confusion, we
have deleted the definition of ``solvent extraction'' from the final
rule and have eliminated any reference to this term in the definition
of no free liquids.
    Presently, many state agencies have established several methods for
verifying compliance with state-imposed ``no free liquids'' conditions.
The majority of states require the use of the Paint Filter Liquids Test
(SW-846, Method 9095), while other states require the Liquids Release
Test (SW-846, Method 9096) or the Toxicity Characteristic Leaching
Procedure (TCLP) (SW-846, Method 1311), among other state defined
standards. Defining ``no free liquids'' in terms of an objective test
enables better implementation and compliance monitoring. By defining
``no free liquids'' in terms of a standard test, we are also addressing
the spirit of many commenters that argued that EPA should specify
technologies that would meet this condition (i.e., EPA should finalize
a more objective definition of ``no free liquids''). While all of the
above tests are objective, for today's rule, EPA is using the Paint
Filter Liquids Test for determining whether solvent-contaminated wipes
contain free liquids. The Paint Filter Liquids Test is already used for
determining compliance with the ``no free liquids'' condition by many
states and is also the test used to implement the restrictions on
disposal of free liquids in the MSWLF regulations (40 CFR 258.28). The
Paint Filter Liquids Test is simple, straightforward, and generally
less costly than the other test methods considered.
    EPA notes that generators do not have to conduct the Paint Filter
Liquids Test for every solvent-contaminated wipe. Rather, generators
must ensure that if the Paint Filter Liquids Test was performed, the
wipe would pass.
    Where authorized states have defined ``no free liquids'' using a
different standard, generators in those states must meet the state
standard for purposes of meeting the ``no free liquids'' condition.
This ensures that today's rule complements existing state policies and,
thus, does not place an unnecessary burden on states and the regulated
community to change existing practices. Of course, the authorized state
standard must be no less stringent than today's definition of ``no free
liquids.'' See section VI.D.3 for more information.
    EPA agrees with the majority of commenters that argued a specific
limit on the maximum amount of solvent, or the concentration of solvent
on a wipe, or a numerical limit on the number of shop towels laundries
or dry cleaners can accept on an annual basis is not necessary and
would be burdensome to implement. We agree that the regulations under
the CWA already impose enforceable limits on point source discharges to
waterways through industrial user and pretreatment requirements.
Today's rule enforces this by requiring that solvent-contaminated wipes
only be sent to laundries and dry cleaners whose discharge, if any, are
regulated under applicable sections of the CWA.
    Moreover, EPA agrees that the ``no free liquids when wrung''
condition could increase, or at least be perceived to increase,
workers' exposure to solvents. Today's definition of when solvent-
contaminated wipes contain no free liquids is sufficient to reduce the

probability of free liquids being transported under today's rule.
Comments: ``Dry'' Condition
    The majority of comments on this issue disagreed with EPA's
proposed ``dry'' condition for disposable wipes going to landfills.
Specifically, commenters argued that the five gram limit per wipe was
arbitrary, inconvenient, unworkable, time-consuming, and potentially
cost-prohibitive to businesses, many of which are small businesses.
Additionally, some commenters pointed out that wipes vary in terms of
size, composition, absorbency, and thickness and that, in some cases, a
wipe may meet the ``dry'' condition (less than five grams of solvent)
but still have liquid solvent that could drip from the wipe and thus,
be released to the environment. In response to EPA's proposed methods
of meeting the ``dry'' condition, commenters stated that solvent
extraction technology was not easily attainable or affordable.
Commenters also argued that EPA's proposal to use normal business
records to comply with the condition would be difficult to implement
and may in fact be an incentive for facilities to use more disposable
wipes than necessary, such as dividing the amount of solvent by an even
larger amount of wipes used each month. Therefore, many commenters
urged EPA to abandon the ``dry'' condition and require solvent-
contaminated wipes going to landfills to meet the ``no free liquids''
or ``no free liquids when wrung'' condition instead. Many commenters
also argued that the same standard should be applied to both reusable
and disposable wipes in order to ease implementation, especially for
facilities that use both types of wipes.
    Of the few commenters that did support the ``dry'' condition, some
argued that this approach is the only practical way to assure
disposable wipes do not contain excessive levels of solvents when sent
to municipal or non-hazardous waste landfills. Other commenters
supported the ``dry'' condition as long as EPA specified in the
regulations which extraction technologies can be presumed to meet the
five gram standard, which would assist implementation and compliance
monitoring.
    Still another commenter argued that the five gram limit per wipe
was not stringent enough because the solvent would exceed the Land
Disposal Restriction standards for disposal.
EPA Response: ``Dry'' Condition
    Based on the comments, the Agency has decided not to finalize the
``dry'' condition for disposable wipes going to landfills, as it would
be burdensome to implement and enforce. In addition, as noted by
commenters, setting a firm quantitative limit on the amount of solvent
in each wipe does not take into account the diverse sizes and types of
wipes in the marketplace. For example, it's possible that some wipes
could contain less than five grams of solvent and still have free
liquids. Some commenters believed we could improve the ``dry''
condition by specifying a list of technologies that could be used to
achieve the standard; however, we understand that these technologies
are expensive and may not always be necessary depending on the type of
wipe and the amount of solvent used. Furthermore, technology changes
over time and thus, specifying a list in the regulations may
unnecessarily preclude newer technologies.
    In choosing what standard to use in place of the ``dry'' condition,
we relied on the results of our risk analysis, which evaluated various
industries, the amount of solvent that was typically placed on wipes,
and how much solvent would eventually be placed into landfills. After
estimating the amount of solvent that could be on a wipe before
disposal and the number of generators potentially disposing of solvent-
contaminated wipes into a MSWLF, the 2012 final risk analysis
demonstrated that 19 of the 20 solvents evaluated did not exceed target
risk criteria when placed into a composite-lined landfill. Therefore,
the ``no free liquids'' condition is appropriate to use to ensure that
solvent-contaminated wipes going to landfills do not exceed the risk
thresholds. Furthermore, the ``no free liquids'' condition is
consistent with what is currently required in the 40 CFR part 258 MSWLF
standards. By using the same standard for disposable and reusable
wipes, we are able to address those comments that urged EPA to finalize
the same condition for both types of wipes in order to ease
implementation and understanding of the regulations, especially for
facilities that use both reusable and disposable wipes.
    EPA does not agree with the commenter that argued that the five
gram limit per wipe was not stringent enough because the solvent would
exceed the Land Disposal Restriction standards for disposal. The Agency
has conducted a robust risk analysis that demonstrates the solvent-
contaminated wipes included under the exclusion for disposable wipes do
not exceed risk thresholds when disposed in a composite-lined landfill.

H. Recordkeeping

    In the November 2003 proposal, EPA did not propose any
recordkeeping requirements for the conditional exclusion for reusable
wipes or for the conditional exclusion for disposable wipes. However,
we did request comment on a number of recordkeeping options, such as
requiring handling facilities that receive shipments of solvent-
contaminated wipes with free liquids to submit a notification to the
state or EPA region. Additionally, we requested comment on whether we
should require generators to keep basic information, such as the volume
of solvent-contaminated wipes generated, where the wipes were sent, and
how many shipments were sent off-site. We also requested comment on
whether generators and handlers should certify that shipments sent and
received met either the ``no free liquids'' or ``dry'' condition, as
appropriate, and whether generators should certify that their employees
are adequately trained to manage the solvent-contaminated wipes.
Lastly, we requested comment on whether the accumulation time limits in
40 CFR 262.34 should be required. If so, then the generator would have
to include a label stating the date accumulation started.
Comments: Recordkeeping
    Many commenters urged EPA not to finalize any recordkeeping or
reporting requirements. These commenters argued that these requirements
would be duplicative of other regulations, for example, OSHA training
requirements and 40 CFR 261.2(f). These commenters stated that
additional recordkeeping, such as one-time notifications,
certifications, or shipping records would place unnecessary burdens on
generators and handling facilities, while providing little, if any,
additional environmental benefit. Additionally, commenters stated that
the goal of this regulation is to simplify requirements and exclude
properly managed solvent-contaminated wipes from hazardous waste
regulations; requiring additional recordkeeping thus runs counter to
that goal.
    Other commenters argued for recordkeeping requirements, including
records of volumes of solvent-contaminated wipes generated, employee
training certifications, records of shipments, a management plan for
meeting the ``no free liquids'' condition, manifests, biennial reports,
notifications, and certifications of meeting the ``no free liquids''
condition, as well as a log or notifications to the generator, state,
or EPA when shipments

of solvent-contaminated wipes are received that contain free liquids.
These commenters stated that recordkeeping requirements are essential
to hold generators and handling facilities accountable under today's
rule. The commenters argued that recordkeeping requirements would not
be overly burdensome to generators and could easily be maintained as
part of existing standard business records. Additionally, such
recordkeeping would assist implementing agencies with ensuring that
solvent-contaminated wipes are properly managed.
EPA Response: Recordkeeping
    EPA agrees with commenters that support incorporating recordkeeping
requirements into the final rule. In evaluating whether to require
recordkeeping for the conditional exclusions for reusable wipes and
disposable wipes, we balanced the need to enable proper implementation
and compliance monitoring of the rule's conditions with the desire to
avoid needless paperwork requirements that may be burdensome to
generators and handling facilities, a concern raised by the commenters
who argued against recordkeeping requirements. We also considered which
recordkeeping requirements would be appropriate for these conditionally
excluded materials.
    After reviewing the comments, we chose to require generators to
maintain records at their site that document (1) the name and address
of the handling facility (i.e., laundry, dry cleaner, landfill, or
combustor); (2) that the 180-day accumulation time limit is being met;
and (3) the description of the process the generator is using to ensure
the solvent-contaminated wipes meet the ``no free liquids'' condition
at the point of being sent for cleaning or disposal.
    The purpose of requiring the name and address of the handling
facility is to ensure that the solvent-contaminated wipes are being
managed in compliance with the conditional exclusion (e.g., for
reusable wipes, that they are sent for cleaning and, for disposable
wipes, that they are sent to an appropriate landfill or combustor).
This information can be easily maintained by the generator using
routine business records, such as contracts and invoices and, thus,
should not pose significant burden on a facility.
    Documenting the accumulation time limit is important to enable
regulatory authorities to monitor compliance with the condition and to
ensure that solvent-contaminated wipes are not stored indefinitely in
lieu of sending the solvent-contaminated wipes to be cleaned or
disposed. This condition is particularly important because the solvent-
contaminated wipes can be accumulated with free liquids under the
exclusion. Thus, there may be an incentive for a generator to store
such wipes indefinitely in order to avoid the hazardous waste disposal
costs associated with the free liquid spent solvent.
    Requiring the description of the process the generator is using to
ensure that the solvent-contaminated wipes contain no free liquids is
critical for assisting implementation and compliance monitoring of this
key condition of today's rule. Today's rule only extends to the
solvent-contaminated wipe and the conditional exclusions do not include
any free liquid spent solvent, which would continue to be subject to
the hazardous waste regulations, as appropriate. It is therefore
imperative that the condition of ``no free liquids'' be met. In order
to ensure that this condition is properly implemented, it is
appropriate to require documentation of the process, methodology, and/
or knowledge that is being used to ensure the solvent-contaminated
wipes managed under today's rule meet the ``no free liquids''
condition.
    We disagree with commenters who wanted additional recordkeeping
requirements, such as biennial reports or records on amounts of
solvent-contaminated wipes generated. We do not find these records are
necessary to ensure that solvent-contaminated wipes meet the conditions
of today's rule. Records of shipments are also unnecessary as long as
the generator documents the name and address of the laundry, dry
cleaner, combustor, or landfill where the solvent-contaminated wipes
are being sent. This documentation then would only have to be updated
in the event the name or address of the destination facility changed.
This serves to keep paperwork burden to a minimum.
    Furthermore, we are convinced that requiring a log or notification
to the generator, state or EPA region by a handler (e.g., laundry) that
receives solvent-contaminated wipes containing free liquids is not
necessary. First, under today's rule, free liquid spent solvent must be
managed according to the hazardous waste regulations, as appropriate.
Thus, any liquid spent solvent that is discovered upon receipt, for
example, by a laundry, must be managed as hazardous waste, if
applicable. (Under today's rule, handlers are not allowed to send back
shipments of free liquid waste to the generator as was proposed in
November 2003. See section VIII.I below for more information.) This
creates a strong incentive for generators to ensure that the solvent-
contaminated wipes meet the ``no free liquids'' condition prior to
sending the wipes to a handler because the generator is likely to incur
a fee imposed by the handling facility for the hazardous waste disposal
of the free liquid spent solvent wastes.
    Additionally, in today's rule we have more clearly defined ``no
free liquids'' using a performance standard based on the Paint Filter
Liquids Test. This test provides a more objective definition than the
November 2003 proposed definition, which specified only that no liquid
solvent could drip from the wipe. Today's standard strengthens the ``no
free liquids'' condition sufficiently so that solvent-contaminated
wipes meeting the standard are not likely to produce free liquids in
transit (as a result of compression, gravity, or percolation).
    Secondly, if a handling facility did receive a shipment of solvent-
contaminated wipes that contained free liquid spent solvent, the spent
solvent would become subject to the reporting and recordkeeping
requirements of the hazardous waste regulations as appropriate to the
amount of hazardous waste generated in that month by the handling
facility. EPA finds that any additional reporting requirements would be
duplicative of what is already required under the hazardous waste
regulations.

I. Handling Facilities

Laundries and Dry Cleaners
    EPA proposed to conditionally exclude from the definition of solid
waste solvent-contaminated reusable wipes that are sent to an
industrial laundry or dry cleaner. Specifically, EPA proposed to
require that these handling facilities manage the solvent-contaminated
wipes in non-leaking, covered containers or in containers that are
designed, constructed, and managed to minimize loss to the environment
before the wipes enter the handling process. If free liquids accumulate
in containers that arrive at a laundry or dry cleaner, EPA proposed
that the handling facility either remove the free liquids and manage
them as hazardous waste or return the closed container to the
generator. Additionally, laundries and dry cleaners could dispose of
the treatment residuals in solid waste landfills if they did not
exhibit a hazardous waste characteristic.
Comments: Laundries and Dry Cleaners
    Some commenters were concerned that contaminated solvents removed

from the solvent-contaminated wipes in laundering and discharged into
waterways would adversely affect human health and the environment.
Commenters believed that laundries and dry cleaners should be required
to demonstrate that they are appropriately managing the solvent removed
from the solvent-contaminated wipes during cleaning. At least one
commenter stated that generators should only be allowed to send
solvent-contaminated wipes to facilities that have been issued a valid
NPDES or State Pollutant Discharge Elimination System permit, pursuant
to section 402 of the CWA, or that have a pretreatment permit with a
POTW, pursuant to section 307 of the CWA.
    A few commenters believed that the conditions for management of
solvent-contaminated wipes at laundries and other such handling
facilities needed to be strengthened and that EPA should require more
specific provisions for container management, storage time limitations,
and notification requirements.
    Some commenters argued against additional requirements on laundries
and dry cleaners and other such handling facilities because the
proposed conditions, in conjunction with existing regulatory programs,
such as the effluent limitation guidelines for wastewater discharges
from industrial laundries and applicable OSHA workplace exposure
standards, already provide appropriate safeguards to protect the
environment and human health. These commenters pointed out that
solvent-contaminated wipes arriving at a laundry or dry cleaner already
meet the standard of ``no free liquids.'' Commenters added that the
solvents contaminating the wipes and removed during the laundering
process are captured by laundry wastewater treatment systems designed
to ensure compliance with applicable wastewater pretreatment permits.
Comments stated that solvents not captured by an industrial laundry's
wastewater treatment system are safely conveyed to a POTW where
secondary biological treatment effectively destroys these organic
compounds. Additionally, in response to EPA's request for comment on
placing specific limits on the maximum amount of solvent on a wipe or a
numerical limit on the number of shop towels laundries or dry cleaners
can accept on an annual basis, most commenters asserted that limits on
the amount or concentration of solvent are unnecessary because CWA/
NPDES permits impose enforceable limits on point source discharges to
waterways (from laundries and dry cleaners) through industrial user and
pretreatment requirements.
EPA Response: Laundries and Dry Cleaners
    We agree with those commenters that argued against additional
requirements, beyond the management conditions included in today's
rule, because, as the commenters argued, laundry and dry cleaner
discharges are regulated under the CWA, which ensures that the solvents
removed from solvent-contaminated wipes during the cleaning process are
properly managed to avoid adverse affects on human health and the
environment. EPA also agrees with commenters that placing specific
limits on the maximum amount of solvent, or the concentration of
solvent on a wipe, or a numerical limit on the number of shop towels
laundries or dry cleaners can accept on an annual basis is unnecessary
because the CWA already imposes enforceable limits on point source
discharges to waterways through industrial user and pretreatment
requirements. (See section VI.D.5 for more information.) Thus, to
reduce confusion, we are clarifying in the regulatory language that we
are allowing reusable wipes (that meet the conditions of today's rule)
to be sent to laundries and dry cleaners whose discharges, if any, are
regulated under the applicable provisions of the CWA.
    Because we agree with commenters seeking strengthened management
conditions, we are requiring in today's rule that handling facilities
must accumulate, store, and manage reusable wipes in non-leaking,
closed containers that are labeled ``Excluded Solvent-Contaminated
Wipes'' when the wipes are not being processed or cleaned.
Additionally, the container must also be able to contain free liquids
should free liquids occur, for example, from percolation and
compression of the wipes. (See section VI.D.1 for further discussion on
this requirement.) However, we disagree that conditions, such as
accumulation time limits for the laundry or further recordkeeping, are
necessary. The business of a laundry or dry cleaner is to clean wipes
in order to provide them to their customers in exchange for revenue. We
do not see an incentive for a laundry or dry cleaner to overaccumulate
solvent-contaminated wipes and thus, do not see a need to regulate to
this end. As for recordkeeping, please see section VIII.H below for our
response to comments regarding this issue. We also agree with
commenters that compliance with applicable OSHA workplace exposure
standards, in conjunction with today's requirement that solvent-
contaminated wipes be managed in closed, non-leaking containers,
provide appropriate safeguards to protect workers.
Landfills
    In the Agency's November 2003 proposal, EPA proposed to allow
solvent-contaminated wipes to be disposed in either a MSWLF or another
non-hazardous waste landfill that meets the standards under 40 CFR part
257 subpart B.\33\ In addition, EPA also proposed to make 11 solvents
ineligible for the exclusion because these solvents are included in the
TC or because they failed EPA's risk screening analysis for the
November 2003 proposed rule. In EPA's October 2009 NODA, which
requested comment on EPA's 2009 revised risk analysis for the solvent-
contaminated wipes rulemaking, EPA requested comment on two additional
approaches for managing disposable wipes. The first approach would
allow the disposal of solvent-contaminated wipes that did not exceed
target risk criteria for an unlined landfill, based on the Agency's
risk analysis, to be disposed in landfills without a liner; solvent-
contaminated wipes that did exceed target risk criteria for an unlined
landfill could only be disposed in a lined landfill. The second
approach would direct all excluded solvent-contaminated wipes,
including those that could safely be disposed in an unlined landfill,
be sent to a Subtitle D MSWLF subject to the requirements in 40 CFR
258.40(a)(2) and (b) (74 FR 55167-8).
---------------------------------------------------------------------------

    \33\ The 40 CFR part 258 MSWLF regulations include design
standards, groundwater monitoring, and other specific management
standards. The 40 CFR part 257 Subpart B Non-Municipal Non-Hazardous
Waste Disposal Unit regulations establish minimum federal criteria,
such as location restrictions and groundwater monitoring, but do not
require liners or other design and management standards (although
states may require additional standards).
---------------------------------------------------------------------------

Comments: Landfills
    Some commenters supported EPA's first approach to allow solvent-
contaminated wipes to be disposed in both types of landfills (lined and
unlined) depending on the type of solvent used on the wipe and whether
that solvent posed a risk, based on the Agency's 2009 revised risk
analysis.
    Other commenters supported the second approach to allow solvent-
contaminated wipes to be disposed only in MSWLFs. These commenters
argued that this approach would be easier to implement because it
avoids the need for generators to separate wipes by solvent,
particularly for wipes used in different parts of a facility, and then
determine whether the solvent-

contaminated wipes could be sent to an unlined or lined landfill.
EPA Response: Landfills
    EPA agrees with those commenters that supported a requirement that
all solvent-contaminated wipes be sent only to MSWLFs operating under
the 40 CFR part 258 standards.\34\ This represents the most
straightforward approach and imposes the least burden to implement and
enforce. Under this approach, generators will not need to keep track of
which excluded wipes are contaminated with which solvents and whether
those solvent-contaminated wipes are being sent to a lined or an
unlined landfill.
---------------------------------------------------------------------------

    \34\ Solvent-contaminated wipes could also be sent to hazardous
waste landfills operating under 40 CFR parts 264 and 265.
---------------------------------------------------------------------------

    Although this approach may technically narrow the number of options
for a generator from those in our proposal (because a generator will
not be able to use a 40 CFR part 257 non-hazardous waste landfill),
this will not constitute an undue restriction for the following
reasons: (1) Generators are likely already using one or more of the
1,908 MSWLFs that operate under the 40 CFR part 258 standards for
disposal of their other solid waste trash; \35\ (2) a 40 CFR part 257
non-hazardous waste landfill may not accept solvent-contaminated wipes
as these landfills are often set up for specific purposes, such as for
large quantities of construction and demolition waste; and, (3) we do
not have any indication that there is a significant cost advantage for
using a 40 CFR part 257 non-hazardous waste landfill as compared to a
40 CFR part 258 MSWLF.
---------------------------------------------------------------------------

    \35\ Municipal Solid Waste Generation, Recycling, and Disposal
in the United States Tables and Figures for 2010, November 2011
http://www.epa.gov/wastes/nonhaz/municipal/pubs/msw_2010_data_tables.pdf.
---------------------------------------------------------------------------

    Any potential benefit gained from allowing the use of a non-
hazardous waste landfill is likely to be insignificant, especially in
light of the increased complexity for implementation and compliance
monitoring that would be required to ensure that certain solvent-
contaminated wipes were being sent to the appropriate landfill.
Combustors
    EPA proposed that municipal and other non-hazardous waste
combustors be allowed to burn solvent-contaminated wipes that meet the
proposed conditions for the exclusion from the definition of hazardous
waste. For solvent-contaminated wipes going to combustors, EPA proposed
to require that these handling facilities manage the solvent-
contaminated wipes in non-leaking, covered containers or in containers
that are designed, constructed, and managed to minimize loss to the
environment before the wipes enter the handling process. If free
liquids accumulate in containers that arrive at a combustor, EPA
proposed that the handling facility either remove the free liquids and
manage them as hazardous waste or return the closed container to the
generator. Additionally, combustors could dispose of the residuals in
solid waste landfills if they did not exhibit a hazardous waste
characteristic.
Comments: Combustors
    Several commenters supported allowing combustion of solvent-
contaminated wipes in a municipal waste combustor or other combustion
facility. These commenters stated that EPA's 2003 risk screening
analysis demonstrates that such combustion practices would be
protective of human health and the environment when conducted in
accordance with applicable permit conditions. Additionally, commenters
stated that this management option would provide an environmentally
beneficial recycling alternative to disposal and would allow facilities
to use solvent-contaminated wipes as supplemental fuels in lieu of
virgin fuels.
    Some commenters raised the concern that some combustion units
allowed in the November 2003 proposal would not address dioxin and
furan formation and that combustors receiving large quantities of
solvent-contaminated wipes containing halogenated solvents (listed F001
and F002 solvents) could become a significant source of dioxin
emissions.
    Additionally, at least one commenter argued that the proposed
management conditions for combustors were not adequately protective of
human health and the environment. This commenter argued that combustors
routinely dump incoming waste into a large bin or concrete pit where it
is then placed into the combustion unit via a clam shell, backhoe, or
similar equipment. This commenter stated that the solvent-contaminated
wipes could pose a risk to the environment, either through
volatilization, release of free liquids, or potential fire. Commenters
urged EPA to specify some minimum standards for management of solvent-
contaminated wipes to be burned in combustors to address risk from
fugitive emissions during the storage and processing of these wipes
prior to and during combustion.
    At least one commenter stated that EPA should allow the solvent-
contaminated wipes to be used for energy recovery in cement kilns
(which are generally regulated under hazardous waste regulations and
thus, have been heretofore receiving disposable wipes).
EPA Response: Combustors
    EPA agrees with commenters that support allowing combustion of
solvent-contaminated wipes in municipal waste combustors and other
combustion facilities. As explained in the November 2003 proposal,
combustion facility owners/operators will be screening wipes
contaminated with hazardous solvents that arrive at their facilities to
ensure they do not violate local permit conditions. In addition, these
combustors are easily capable of destroying the solvent, as described
in section IV.F.11 of the Technical Background Document (68 FR 65602).
    EPA does not agree with commenters that raised concerns that
certain combustion units would not address dioxin and furan formation
from combustors receiving large quantities of solvent-contaminated
wipes containing halogenated solvents. As explained in the November
2003 proposal, EPA has promulgated revised air emission standard
requirements under the New Source Performance Standards for municipal
waste combustors and commercial and industrial solid waste incinerators
(68 FR 65602). Thus, municipal waste combustors and other combustion
facilities must comply with emission standards, including those that
address dioxin and furan emissions. To reduce confusion, we have
revised the regulatory language to be clear that we are allowing
disposable wipes (that meet the conditions of today's rule) to be sent
to municipal waste combustors and other combustion facilities that are
regulated under the New Source Performance Standards in section 129 of
the CAA.
    EPA agrees with commenters' concern about the management of
solvent-contaminated wipes prior to combustion. The provisions in
today's rule will adequately address those commenters' concerns.
Specifically, under today's rule, solvent-contaminated wipes must not
contain free liquids when transported to a municipal waste combustor or
other combustion facility. EPA has clarified this standard by defining
``no free liquids'' using the Paint Filter Liquids Test. The use of
this test enables proper implementation of the ``no free liquids''
condition and, combined with today's requirement that generators
document how they are meeting this condition,

should minimize the possibility of free liquids occurring after the
solvent-contaminated wipes leave the generator. If, however, free
liquids do reach the combustor, they must be removed and managed under
the applicable hazardous waste regulations.
    Additionally, EPA is requiring that solvent-contaminated wipes be
accumulated, stored, and transported in non-leaking, closed containers
that are labeled as ``Excluded Solvent-Contaminated Wipes.'' This
container standard will prevent release of the solvent to the air or
through spills while being managed by the combustor.
    EPA confirms that solvent-contaminated wipes may continue to be
sent to RCRA hazardous waste combustors, boilers, and industrial
furnaces (as well as hazardous waste landfills) regulated under 40 CFR
parts 264, 265, or 266 subpart H, which includes cement kilns that are
operating under these regulations. To further clarify this point, we
have added these citations to the final regulatory language for this
exclusion.
Comments: Free Liquids Received by Handling Facilities
    Some commenters agreed with EPA's proposal to maintain the
conditional exclusion for solvent-contaminated wipes that contain some
free liquids when received by the handling facility. Commenters argued
that free liquids may inadvertently make their way to the handling
facility as a result of compression, gravity, or percolation effects on
the wipes during transport or by improper management of the solvent-
contaminated wipes by the generator prior to transport. These
commenters agreed that the handling facility should be allowed to
manage the liquids as hazardous waste or send the shipment back to the
generator. At least one commenter stated that the handling facility
should not be considered the generator of the solvents contained on the
solvent-contaminated wipes and should not be responsible for removing
the free liquids. Some commenters argued that EPA should allow handling
facilities to recover the free liquid spent solvent through use of
appropriate technology without classifying the liquid as hazardous
waste.
    Other commenters disagreed with EPA's proposed approach and argued
that a handler who discovers free liquids should not be allowed to
return the container with the solvent-contaminated wipes and free
liquid to the generator. These commenters argued that containers with
liquid hazardous waste should not be considered as having met the
conditional exclusion and should only be transported by licensed
hazardous waste transporters to permitted hazardous waste facilities.
Additionally, commenters argued that allowing shipments to be returned
to the generator may create problems in which the generator refuses to
accept the returned solvent-contaminated wipes, or goes out of business
after sending the wipes to the receiving facility.
    In a similar vein, some commenters noted that generators have their
own incentives to ensure there are no free liquids because generators
could incur additional transportation (if the container is returned) or
additional disposal costs (if the container and its contents are
managed by the receiver as hazardous waste).
EPA Response: Free Liquids Received by Handling Facilities
    EPA agrees with commenters that supported EPA's proposal to
maintain the conditional exclusion for solvent-contaminated wipes that
contain some free liquids when received by the handling facility. In
the November 2003 proposal, EPA acknowledged that free liquids may be
generated during transport to a handling facility, despite best efforts
by the generator. Today's final rule further decreases the frequency of
free liquids occurring during transport by defining the ``no free
liquids'' condition for wipes using an objective test method and
requiring generators to document their method for meeting this
condition. Additionally, we agree with commenters who stated that
generators have an economic incentive to ensure the solvent-
contaminated wipes contain no free liquids.
    However, if free liquids are observed in a container at the
handling facility, EPA is requiring handlers to manage the free liquids
according to all applicable hazardous waste regulations in 40 CFR parts
260 through 273. The wipes themselves may remain under the exclusion
provided that the conditions of the exclusion were met (e.g., the
solvent-contaminated wipes and the container contained no free liquids
at the point of transport by the generator). We do not agree with
commenters that argue the handling facility should not be responsible
for removing free liquids and that the containers with free liquids
should be sent back to the generator. This approach would be
inconsistent with the requirements for managing hazardous waste and
increases the time the free liquids spend in transit, and the
possibility of their release, since the generator would likely have to
send them off-site again for their ultimate disposition. This approach
supports those commenters who argued that containers with liquid
hazardous waste should only be transported by licensed hazardous waste
transporters to permitted hazardous waste facilities and should not be
sent back to generators because these generators may refuse to accept
the waste or may have gone out of business.
    Laundries or dry cleaners may also recycle free liquid spent
solvent within their allowed accumulation period (e.g., 90 or 180 days)
without a RCRA permit under the provisions of 40 CFR 261.6(c), which
exempts the recycling process itself from certain hazardous waste
requirements.
    If the generator complies with the conditions of today's rule, free
liquids during transport should be a very rare occurrence. Today's rule
provides a strong incentive for generators to meet the ``no free
liquids'' condition because handling facilities will likely expect them
to bear the additional costs to manage the free liquids as hazardous
waste.

J. Other Major Comments

    EPA also sought comment on a few additional issues, including (1)
co-contaminants; (2) intra- and inter-company transfers; (3) exotic
solvents; and (4) state authorization.
Co-Contaminants
    In the November 2003 proposal, EPA stated that the rule ``is not
intended to override EPA's mixture and derived from rule regarding
contaminants on industrial wipes other than the solvents specified in
this proposal'' (see 68 FR 65602). Thus, if the solvent-contaminated
wipes contain a listed waste other than the identified solvents, the
wipes would remain listed hazardous waste and would not be eligible for
the exclusion. EPA also proposed that solvent-contaminated wipes that
exhibit a characteristic of hazardous waste other than ignitability due
to co-contaminants (i.e., any contaminant other than a solvent) would
not be eligible for the conditional exclusions. However, EPA proposed
that wipes co-contaminated with ignitable waste would remain eligible
for the exclusions if they met the other conditions. EPA based this
proposal on the fact that the solvent-contaminated wipes could be
ignitable due to the nature of the solvents on them, and because the
conditions would adequately address this risk.
Comments: Co-Contaminants
    Some commenters encouraged EPA to allow the conditional exclusions
to apply regardless of the presence of co-

contaminants, including the presence of other listed hazardous waste or
characteristic waste. These comments claimed prohibiting solvent-
contaminated wipes that contain co-contaminants will reduce or
eliminate the eligibility of the majority of wipes from the exclusions.
    Other commenters agreed with EPA's proposal not to allow solvent-
contaminated wipes to be excluded if they were hazardous due to co-
contaminants arising from other listed hazardous waste or exhibiting a
hazardous waste characteristic. They argued that no assessment was made
of the co-contaminants associated with the solvent-contaminated wipes,
in particular metals, and EPA must ensure that other hazardous
constituents do not result in adverse risk or environmental impact.
These commenters also opposed allowing ignitable wipes to be eligible
for the exclusions if the co-contaminant is an ignitable non-solvent
constituent.
EPA Response: Co-Contaminants
    EPA agrees with commenters that solvent-contaminated wipes that are
hazardous due to the presence of co-contaminants that are other listed
hazardous waste or that exhibit a hazardous waste characteristic (other
than ignitability) should not be eligible for the conditional
exclusions. Therefore, EPA is finalizing the provision regarding co-
contaminants as proposed. That is, wipes contaminated with non-solvent
listed waste (for example, as a result of a hazardous waste spill
clean-up) or that exhibit a hazardous waste characteristic other than
ignitability due to a non-solvent contaminant are not eligible for the
conditional exclusions. EPA agrees with commenters that we did not
evaluate the risks posed by solvent-contaminated wipes that are
contaminated with other listed hazardous wastes and thus, it is not
appropriate to exclude them in this rulemaking. Likewise, solvent-
contaminated wipes that exhibit a characteristic due to constituents
other than one of the excluded solvents (e.g., co-contaminant metals)
are not included in the conditional exclusions (with one exception for
ignitable-only wastes) for similar reasons (i.e., solvent-contaminated
wipes contaminated with these other co-constituents were not
evaluated).
    We agree with commenters who sought to make solvent-contaminated
wipes that are co-contaminated with ignitable-only wastes eligible for
the conditional exclusion. Because solvents are often ignitable, as a
practical matter it would be difficult to distinguish between those
solvent-contaminated wipes that are ignitable due to the solvent from
those that are ignitable due to a non-solvent co-contaminant. And such
a distinction is unnecessary because the conditions of the exclusion
(e.g., no free liquids and closed, non-leaking containers) address the
issue of ignitibility no matter what the source.
Intra- and Inter-Company Transfers
    EPA proposed to allow intra-company transfers of solvent-
contaminated wipes with free liquids, which would allow facilities to
send their wipes to another facility within their same company that
would remove sufficient solvent from the wipes so they could meet the
``dry'' condition or the ``no free liquids'' condition, as appropriate.
The receiving facility would have to manage the extracted solvent
according to the applicable hazardous waste regulations found under 40
CFR parts 260 through 273. We proposed this provision to encourage
additional solvent recycling and energy recovery, as well as to assist
facilities in meeting the ``no free liquids'' or ``dry'' condition.
    The Agency also requested comment on allowing inter-company
transfers of solvent-contaminated wipes with free liquids, which would
allow generators to ship solvent-contaminated wipes with free liquids
to any facility if the receiving facility uses a solvent extraction
and/or recovery process to remove enough solvent from the wipes for
them to meet the ``no free liquids'' condition.
Comments: Intra- and Inter-Company Transfers
    Some commenters supported allowing intra-company transfers of
solvent-contaminated wipes containing free liquids, if the receiving
facility has a solvent-extraction and/or recovery process. These
commenters argued that intra-company transfers would allow smaller
facilities access to solvent extraction equipment or technologies at
larger facilities, thus increasing solvent reuse while decreasing off-
site disposal costs. At least one commenter, however, did not agree
that allowing intra-company transfers would significantly increase
solvent recycling because facilities are unlikely to invest in such
extraction technologies.
    Other commenters argued that intra- and inter-company transfers of
solvent-contaminated wipes with free liquids should not be eligible for
the exclusions. These commenters stated that excluding saturated
solvent-contaminated wipes transported off-site for solvent reclamation
runs counter to the premise that wipes contain no free liquids. They
argued that it is not appropriate to allow free liquid spent solvent
waste to be transported without RCRA controls, such as a manifest and
other minimum protections. They further argued that allowing free
liquid spent solvents to be transported freely to multiple sites
creates an opportunity for further exposure and potential for
environmental releases.
EPA Response: Intra- and Inter-Company Transfers
    EPA has chosen not to finalize the provision allowing intra-company
or inter-company transfers for solvent extraction. We agree with those
commenters who argued that allowing off-site transport of saturated
solvent-contaminated wipes runs counter to the premise of today's rule.
Saturated solvent-contaminated wipes inherently present greater risk of
environmental release than wipes containing no free liquids and the
conditions of today's rule may not be adequate to address the risks
posed by transport of solvent-contaminated wipes containing free
liquids.
    Although we acknowledge commenters' arguments that intra-company
transfers may allow smaller facilities access to solvent extraction
equipment and technologies and therefore increase solvent reuse, we
note that, since this rule was proposed in November 2003, EPA has
finalized 40 CFR 261.4(a)(23), which allows off-site transfers of
hazardous secondary materials being reclaimed under the control of the
generator, provided certain conditions are met. Therefore, generators
of solvent-contaminated wipes that wish to transfer their wipes within
the same company for the purposes of reclamation may use this
exclusion, promulgated in October 2008 (73 FR 64668).
Exotic Solvents
    In the November 2003 proposal, EPA stated that it had learned of
new, ``exotic'' solvents on the market, such as terpenes and citric
acids, that, while labeled as non-hazardous, could actually be
flammable (68 FR 65600). Stakeholders had informed the Agency that,
under certain conditions that have yet to be determined, the solvent-
contaminated wipes that contain these exotic solvents may spontaneously
combust. To prevent combustion, generators have wet down the wipes with
water.
    In the proposal, EPA requested information and comments on these
exotic solvents and how they are presently managed. The Agency stated
that some stakeholders have suggested that EPA should allow generating

facilities that are using one of these exotic solvents to wet down the
wipes with water and thus, allow the off-site transport of these
solvent-contaminated wipes with free liquids.
Comments: Exotic Solvents
    A few commenters urged EPA to include special conditions for
handling of such exotic solvents in the final rule, noting that wipes
that contain certain vegetable-based oils could increase the
possibility of spontaneous combustion during storage. These commenters
recommended that EPA give special consideration to the use of water to
mitigate potential spontaneous combustion due to these exotic solvents.
    Another commenter argued that there is no need to address exotic
solvents in the final regulation since the current hazardous waste
regulations adequately cover such waste streams. The commenter added
that while adding water to the wipes might reduce ignitability, it
would also add waste volume and confuse the issue of free liquids.
    Still another commenter disagreed with the term exotic solvents
because the term suggests that such solvents are particularly
dangerous, when, in fact, these solvents are almost always less
potentially harmful to human health and the environment than the
petroleum-based solvents they often replace. The commenter stated that
these solvents typically exhibit a high flash point (>140 degrees F),
are readily biodegradable, and have a low human and environmental
toxicity than the more flammable petroleum-based solvents. This
commenter stated that the most common concern with citrus-based
solvents is their biodegradability, because, as the substance breaks
down, heat is generated. This commenter also said that some citrus-
based solvents biodegrade rapidly enough to generate significant
quantities of heat and, if this heat is not allowed to dissipate, as
with a closed container of solvent-contaminated wipes, the heat can
raise the solvent to its flash point, thus causing spontaneous
combustion.
    This commenter argued that the safety considerations in preventing
spontaneous fires have long been considered an acceptable practice.
This commenter stated that often, wipes are wetted to the point where
they would not pass a ``no free liquids'' test. This practice, the
commenter stated, however, does not violate current state policies nor
would it violate the Agency's proposed solvent-contaminated wipes rule
because citrus-based solvents are not RCRA regulated hazardous waste.
As long as citrus-based solvents are not commingled with other RCRA
regulated solvents, the commenter argued that the wetting of wipes
containing citrus-based solvents to the point at which the wipes
contain free liquids is not of regulatory concern.
EPA Response: Exotic Solvents
    EPA agrees with commenters that stated wipes contaminated with
exotic solvents that do not exhibit a hazardous waste characteristic
and which are not listed hazardous wastes are not subject to RCRA
hazardous waste regulation and are thus, outside the scope of today's
rulemaking. In some cases, however, although the solvent may not
exhibit a hazardous characteristic based on its flash point, a wipe
contaminated with that solvent may be hazardous because it can oxidize
and spontaneously combust. EPA did not intend to imply in the November
2003 proposal that wipes contaminated with these solvents would not be
ignitable under RCRA. EPA considers wastes that can spontaneously
combust at any point in their management as potentially meeting the
definition of ignitibility under 40 CFR 261.21(a)(2). Generators are
responsible for making a hazardous waste determination as is required
for any wastestream.
    We recognize that generators and handlers may sometimes wet down
wipes contaminated with exotic solvents to prevent spontaneous fires
from occurring. Although wetting these wipes may be appropriate for
managing the on-site risk of spontaneous combustion, we do not agree
that these wipes should be allowed special consideration under today's
exclusions. If wipes contaminated with solvents must be wetted to the
point where they would not pass a ``no free liquids'' test at the point
of transport for cleaning or disposal, then EPA believes they should
not be eligible for today's exclusions. This approach is consistent
with wipes containing F-listed solvents that would not pass the ``no
free liquids'' test at the point of transport from the generator to the
handling facility in order to minimize release of solvents to the
environment. While EPA supports generators' choices to use less toxic
solvents, we encourage generators to work with their suppliers to
understand and become aware of any potential hazards that could arise
from using solvents in conjunction with wipes, and to appropriately
classify and manage them.
Comments: State Authorization
    Some commenters argued that EPA should require the rule be
implemented in all 50 states to ensure national consistency of the
regulations regarding solvent-contaminated wipes. At least one
commenter noted that, because this regulation is not specifically
authorized under the Hazardous and Solid Waste Amendments of 1984
(HSWA), it will not be effective automatically in all states and thus,
EPA should conduct comprehensive outreach with the states to adopt the
proposed conditional exclusions when they are finalized.
    Other commenters argued that EPA's final rule should allow states
to adopt the federal rule with modifications and should allow states to
adopt equally protective provisions, which will enable consistency with
the states' current policies, many of which have been in effect since
1994. Additionally, these commenters urged EPA to be cognizant of the
fact that many states have had over a decade of experience in
establishing cost-effective, practical, and protective regulatory
programs for solvent-contaminated wipes. The commenters argued that EPA
should be cautious to avoid interfering with pre-existing and equally-
protective state programs that already are in place for the management
of solvent-contaminated wipes.
    Another commenter argued that, with respect to the rule's reusable
wipes provision, EPA has not made clear whether it considers the
exclusion to be an ``exit'' mechanism from otherwise applicable
hazardous waste regulatory requirements or, in light of EPA's pre-
existing decision to allow states to determine their own regulatory
status of reusable wipes, a first-time hazardous waste ``entry''
mechanism for listed solvent-containing laundered wipes. This commenter
argued, if the former is the case, EPA should clarify that as a matter
of federal law, the full set of RCRA-authorized state hazardous waste
regulations should be immediately applicable to reusable wipes unless
and until the provisions of the final rule for reusable wipes are
implemented lawfully by authorized states. If the latter is the case,
then consistent with EPA's prior determinations regarding the status of
hazardous waste listings involving solvent ``mixtures'' under the HSWA
amendments, the commenters argued those provisions of the final rule
must be classified as a ``HSWA rule'' that is immediately effective in
all respects in all states. In either case, in order to comply with its
own RCRA state authorization regulations and guidance, the commenters
stated that EPA needs to clarify that states whose current policies
governing reusable wipes are less stringent in any respect than the new
federal conditional exclusion must amend their RCRA-

authorized hazardous waste regulations as necessary to ensure that all
the conditions of the final exclusion for reusable wipes are provided
for in duly promulgated regulations of those states.
EPA Response: State Authorization
    EPA does not agree that we should require the rule be implemented
in all 50 states. Under RCRA section 3006, EPA may authorize qualified
states to administer the RCRA Subtitle C hazardous waste program within
the state. Following authorization, the authorized state program
operates in lieu of the federal regulations. Authorized states are
required to modify their programs only when EPA promulgates federal
requirements that are more stringent or broader in scope than existing
federal requirements. RCRA section 3009 allows states to impose
standards more stringent than those in the federal program (see 40 CFR
271.1). Therefore, authorized states may, but are not required to,
adopt federal regulations, both HSWA and non-HSWA, that are considered
less stringent than previous federal regulations. See section X for
more information on state authorization under RCRA. Because today's
rule finalizes conditional exclusions from the definition of solid and
hazardous waste, it is less stringent than previous federal regulations
and thus, EPA cannot mandate that the rule become effective in all 50
states. However, we encourage states to adopt today's exclusions to
reduce regulatory burden and maximize national consistency of
regulations regarding solvent-contaminated wipes.
    EPA agrees with commenters that states may adopt the federal rule
with modifications provided their state programs are at least as
stringent as the federal program per the provisions of 40 CFR
271.21(e). This allows some consistency with the states' current
policies, which have been in effect for many years. For example, we
specifically allow authorized states to specify a different standard or
test method for determining that solvent-contaminated wipes contain no
free liquids. Where an authorized state standard exists, generators
must meet that standard in lieu of the Paint Filter Liquids test for
purposes of meeting the ``no free liquids'' condition. Of course, the
authorized state standard must be no less stringent than today's
definition of ``no free liquids.''
    EPA does not agree that today's rule establishes for the first time
that solvent-contaminated wipes are solid and hazardous wastes. In
fact, the 1994 Shapiro memo plainly describes that a ``wiper can only
be defined as listed hazardous waste if the wiper either contains
listed waste, or is otherwise mixed with hazardous waste. Whether or
not a used wiper contains listed hazardous waste, is mixed with listed
hazardous waste, only exhibits a characteristic of hazardous waste, or
is not a waste at all, is dependent on site-specific factor(s); this is
not a new policy.'' \36\ Clearly, EPA has always considered solvent-
contaminated wipes subject to solid and hazardous waste determinations.
Therefore, today's rule conditionally excluding solvent-contaminated
wipes is promulgated under the authority of sections 2002, 3001-3010
and 7004 of the Solid Waste Disposal Act of 1965 and is not a HSWA
rule.
---------------------------------------------------------------------------

    \36\ See ``Industrial Wipers and Shop Towels under the Hazardous
Waste Regulations,'' Michael Shapiro, February 14, 1994. This memo
can be found in RCRA Online, Number 11813 and in the docket for
today's rule.
---------------------------------------------------------------------------

    In response to the argument that reusable wipes must be managed as
hazardous wastes unless and until the state adopts the conditional
exclusion, we note that, as stated in the November 2003 proposal, the
1994 Shapiro memo established federal policy with regard to solvent-
contaminated wipes that deferred the determination of their regulatory
status in case-specific scenarios to the states and EPA Regions (68 FR
65617). This deferral has resulted in the development of various state
programs for reusable wipes. Therefore, authorized states whose
programs include less stringent requirements than today's final rule
are required to modify their programs to maintain consistency with the
federal program per the provisions of 40 CFR 271.21(e). In addition,
any states that delineate their program for reusable wipes in guidance
documents or interpretive letters will need to promulgate enforceable
regulations, as required by 40 CFR 271.21(a). Because today's rule is a
non-HSWA rule, the current state requirements remain in place until the
state adopts requirements equivalent to these federal requirements.

IX. Major Comments on Risk Analysis

    The Agency received comments on both the risk screening analysis
from the November 2003 proposal and on the revised risk analysis
presented in the October 2009 NODA. Many of the comments and criticisms
of the original analysis from November 2003 were addressed by the
revisions to the risk analysis undertaken and published for comment in
the October 2009 NODA. In the following responses, we will first
address the comments on the landfill loading calculations (i.e., how
much of the solvents and sludges might be disposed in landfills under
an exclusion) in the 2003 risk screening analysis for the November 2003
proposal and in the 2009 revised risk analysis for the October 2009
NODA. We will then respond to the comments on how the Agency calculated
the risk-based mass loading limits for the solvents and the sludges in
the 2003 risk screening analysis for the November 2003 proposal and in
the 2009 revised risk analysis for the October 2009 NODA.

Comments: November 2003 Solvent Loading Calculations

    The Agency received many public comments in response to EPA's
November 2003 proposed rule regarding the approach and assumptions used
in estimating the quantity of solvent which might be disposed in a
landfill, known as landfill loading. Most of these comments were
related to how the Agency chose the various values used as inputs to
the calculations. Some commenters criticized the use of ``high-end
assumptions'' for key input data, while other commenters suggested we
underestimated these input data. For disposable wipes, the input data
questioned included the following: number of generators, quantity of
solvent on a wipe, the percent of wipes in a sector containing the
solvents, and number of generators using a single landfill for
disposal. For reusable wipes, the key input data at issue included
quantity and distribution of wipes washed at each laundry,
concentrations of solvents in washwater, partitioning of solvents to
the sludge, and number of laundries using a single landfill for sludge
disposal.

EPA Response: November 2003 Solvent Loading Calculations

    In response to these comments, we completely revised the landfill
loading calculations and presented our new analysis in the October 2009
NODA (see the document entitled ``Landfill Loadings Calculations for
Disposed Solvent-Contaminated Wipes and Laundry Sludge Managed in
Municipal Landfills,'' October 2008; this is referred to below as the
``Landfill Loadings Report''). The Landfill Loadings Report, and the
associated appendices, includes improvements in referencing and
describing the assumptions used for the above input data, such as the
amount of solvent on each wipe, the fraction of wipes containing the
listed solvent, and the number of wipes used per facility. To account
for the variability in these parameters (e.g., facilities using

different quantities of solvent), we used a probabilistic analysis,
such that the calculation inputs account for the full range of data
available. Therefore, we did not use ``high-end'' parameters in our
analysis, except as part of a range which also includes less
conservative values. The probabilistic approach used in the revised
landfill loading analysis addresses the potential to overestimate or
underestimate the input data used in the solvent loading calculations.
The Landfill Loadings Report also includes an analysis of uncertainty
and sensitivity, which were evaluated using a probabilistic analysis.
Therefore, we believe that this analysis presented in the October 2009
NODA addresses the comments received on the landfill loading
calculations presented in the November 2003 proposal.
Comments: 2009 Revised Risk Analysis Solvent Loading Calculations
    As described earlier in the background section of this notice, we
undertook an external peer review of the 2009 revised risk analysis and
addressed those comments prior to presenting the new risk analysis in
the October 2009 NODA. Commenters generally supported our conclusion
that 10 of the 30 solvents have no use, or very limited use, as
solvents on wipes. However, some commenters stated that EPA used
limited data sets, resulting in over-conservative mass loading levels
for the disposable wipes. One commenter indicated that extreme solvent
loading values are inconsistent with the implicit assumption that the
solvent-contaminated wipes meet the conditions of the exclusion (e.g.,
no free liquids). The commenter stated that establishing an ``upper
bound'' for the amount of solvent on each wipe would more accurately
account for the ``no free liquids'' condition.
    Another commenter provided comments specific to the analysis for
solvent loadings for reusable wipes. This commenter provided updated
information collected in surveys for various input parameters related
to the sludge generated by facilities that laundered reusable wipes
(e.g., the quantity of wastewater generated and the quantity of towels
being processed).
EPA Response: 2009 Revised Risk Analysis Solvent Loading Calculations
    In response to comments on over-conservative mass loading levels
for disposable wipes, we note that the report typically used
distributions that resulted in the best fit of the available data.
While setting an upper bound for the amount of solvent on a wipe is one
approach to account for the ``no free liquids'' condition, selecting a
precise value for this upper bound is difficult. The initial
sensitivity analysis presented in the report (i.e., section 2.4.2 of
the Landfill Loadings Report) suggests that the amount of solvent on
the solvent-contaminated wipes is not a particularly sensitive input
parameter, so modifications in this parameter are not expected to
affect the results significantly. To fully respond to the comment, we
conducted further sensitivity analyses by truncating this parameter at
a lower value (to be more consistent with observed data) and confirmed
that this change would lower the landfill loading estimates by less
than 10%. Therefore, we find that the slightly more conservative
approach used in conducting the analysis is reasonable.
    Regarding the information provided by one commenter for reusable
wipes, we decided to modify our analysis to incorporate the more recent
data, where appropriate. We made a case-by-case evaluation of the data
provided by the commenter, and modified the calculations accordingly.
Using the updated data on the pounds of towels processed per year and
the resulting washwater used lowered the mass loadings calculated for
sludges generated by the laundries by about 50%. These changes had
little effect on the overall risks presented by the combined disposal
of disposable wipes and laundry sludges, because the sludges
represented a relatively small fraction of the combined risk for the
solvents. However, the effect of these modifications was sufficient to
reduce the combined risk results presented in the October 2009 NODA for
tetrachloroethylene in a composite-lined landfill, such that this
chemical would meet the target risk criteria (a cancer risk of 1.0 x
10-5, based on the 90th percentile estimated landfill
loading and the 90th percentile risk-based mass loading limit). As
noted in the background section of this notice, the Agency has since
issued a new human health assessment for tetrachloroethylene, which
included updated health-based values. When we substituted the new
health-based values for tetrachloroethylene in our final risk
evaluation (see the Addendum in the docket for this rulemaking), the
combined risks for this chemical in a composite-lined unit dropped even
further, such that the risks were well below the target risk criteria,
with or without the modifications to the sludge data based on the
commenter's new data.
    Responses to all comments on the landfill loading estimate used in
the November 2003 proposal and the October 2009 NODA are provided in
the docket.\37\ The docket also contains the final landfill loadings
report (``Landfill Loadings Calculations For Solvent-Contaminated
Wipes,'' January 2012), which reflects the modifications made in
response to the public comments and external peer reviewer comments on
the risk analysis.
---------------------------------------------------------------------------

    \37\ See the docket for ``Response to Comments on the 2003
Proposal on the Landfill Loadings Calculations for Solvent-
Contaminated Wipes,'' and ``Response to Comments on the 2009 NODA on
the Landfill Loadings Calculations for Solvent-Contaminated Wipes,''
and ``EPA's Response to Peer Reviewer Comments on the Landfill
Loadings Calculations for Solvent-Contaminated Wipes.''
---------------------------------------------------------------------------

Comments: Other Aspects of 2003 Risk Screening Analysis for November
2003 Proposal

    EPA received many comments on other aspects of the 2003 risk
screening analysis used to support the November 2003 proposal. Most of
these comments were addressed in the 2009 revised risk analysis in the
October 2009 NODA. Several commenters expressed concern that the 2003
risk screening analysis was overly conservative. Concerns expressed
included the following: use of a simple deterministic approach based on
high end or average input values; landfill assumptions did not consider
liners or chemical degradation mechanisms; use of the highest leachate
concentrations; use of fixed distance to receptors, as well as others.
    Other commenters expressed concerns that the 2003 risk screening
analysis underestimated risk.\38\ Other comments questioned our
exposure assumptions, our use of generic Dilution and Attenuation
Factors (DAFs) to estimate exposure point concentrations, and our lack
of response to the peer reviewer comments. We also received comments
that the 2003 risk screening analysis failed to consider other
important indirect exposure pathways for humans and the environment
(e.g., runoff and erosion, particulate emissions, and possible food
chain risks).
---------------------------------------------------------------------------

    \38\ Many of these comments concerned our assumptions for the
amount of solvent contained on the wipes; the new Landfill Loadings
Report presented in the October 2009 NODA addressed these comments,
as described previously.
---------------------------------------------------------------------------

    Commenters also stated that the 2003 risk screening analysis only
considered a single solvent constituent from a single source going to a
single landfill, and that EPA assumed that the landfill receives wipes
from no other sources. Commenters noted that the target risk criteria
used were inadequate to allow margins for other contaminants migrating
from the landfill.

EPA Response: Other Aspects of 2003 Risk Screening Analysis for
November 2003 Proposal

    In response to comments on the 2003 risk screening analysis for the
November 2003 proposal, the Agency undertook a more robust risk
analysis. This 2009 revised risk analysis, which was presented in the
October 2009 NODA, was probabilistic in nature and used Monte Carlo
methods to characterize the variability and uncertainty associated with
the modeling. The 2009 revised risk analysis results included solvent-
specific, risk-based mass loading limit (RB-MLL) estimates for both
unlined and composite-lined landfill scenarios. In addition, the Agency
developed and used a new landfill coupled reactor model (LFCR), which
allowed the modeling to account for solvent biodegradation and
partitioning between air, water, and solid phases while in the
landfill. The LFCR model was run to develop distributions of estimates
of landfill leachates, which were used as input to EPA's Composite
Model for Leachate Migration with Transformation Products (CMTP)
groundwater model. The time-averaged solvent concentrations were used
as input to the downstream exposure model.
    The probabilistic approach used in the 2009 revised risk analysis
addresses the potential to either overestimate or underestimate the
risks from disposal of solvent-contaminated wipes and sludges in
landfills. For example, the 2009 revised risk analysis presented in the
October 2009 NODA addresses the exposure assumption comments primarily
through the use of data distributions for exposure factors, which were
developed based on EPA's guidance (e.g., the EPA Exposure Factors
Handbook). Regarding the use of generic DAFs, the 2009 revised risk
analysis did not use generic DAFs, but rather reflected solvent-
specific modeling with a probabilistic analysis, which included
national-level modeling using EPA's CMTP groundwater model. As noted in
the background section of this notice, we submitted the 2009 revised
risk analysis for extensive peer review and responded to the comments,
as appropriate. Our full response to the peer reviewer comments on the
2009 revised risk analysis is in the docket for today's final rule.
    In the 2009 revised risk analysis, we also reevaluated the
potential for risk via indirect exposure pathways, as well as the
potential for significant impacts on the environment. We developed the
RB-MLLs for the exposure pathways that pose the greatest potential
concern. We considered the physical and chemical properties of the
chemicals of interest and focused our evaluation primarily on direct
exposure pathways. The 20 solvents evaluated include a range of
volatile and semi-volatile organic chemicals, most of which have
relatively short environmental half-lives (as compared to persistent
organic chemicals). The primary release mechanisms from landfills are
diffusion and advection into the air and leaching to groundwater. The
generally low values for partition coefficients for these solvents
strongly suggest that indirect exposure pathways will either be
incomplete or contribute negligibly to total exposure. The conclusion
that these solvents are insignificant contributors to risk via indirect
exposure pathways (for a landfill source) is consistent with other risk
analyses of landfill waste management scenarios undertaken by the
Agency.\39\ Furthermore, landfills maintain controls for particulate
air releases and for soil erosion and runoff; regulations for MSWLFs
include run-on/runoff controls (40 CFR 258.26), daily cover (Sec.
258.21), and compliance with the CAA requirements (Sec.  258.24). Thus,
the primary focus of the risk modeling was to assess direct exposure
pathways to the air and groundwater. The commenters did not provide any
information to suggest that these indirect exposure pathways would
alter the RB-MLLs.
---------------------------------------------------------------------------

    \39\ For example, see EPA's evaluation of potential risks from
landfill disposal for paint production wastes as described in the
proposed rule; 66 FR 10060, February 13, 2001.
---------------------------------------------------------------------------

    Regarding multiple facilities using the same landfill, the 2009
risk analysis presented in the October 2009 NODA evaluated multiple
facilities disposing of solvent-contaminated wipes in one landfill. We
used a Monte Carlo analysis to represent the variability of generator
and landfill locations; the distribution used ranged from 2 to 67
generators per landfill. In addition, the overall loadings assumed were
conservative estimates, as described in the Landfill Loadings Report.
    EPA disagrees with suggestions by a commenter that EPA should use
more restrictive target risk criteria to address other possible sources
of the solvents of concern. The Agency believes that the risk criteria
used (1E-5 cancer risk and HQ less than or equal to 1.0 for non-cancer
risk) are appropriate for a listing decision, especially in light of
the conservative approach used in the overall risk evaluation.
Furthermore, we point out that the 2012 final risk analysis indicates
that the risks for the solvent-contaminated wipes in composite-lined
landfills were well below the target risk criteria for all of the
solvents (except for trichloroethylene, which is not eligible for the
exclusion for disposable wipes), i.e., the solvent landfill loadings
are more than a factor of ten below the risk-based mass loading
limits.\40\ Therefore, even if the Agency used lower target risk
criteria, as suggested by the commenter, the disposal of solvent-
contaminated wipes and sludge in composite-lined landfills would not
present a significant risk for the solvent chemicals included in the
exclusion.
---------------------------------------------------------------------------

    \40\ See Table 5 in ``F001-F005 Solvent-Contaminated Wipes and
Laundry Sludge: Comparison of Landfill Loading Calculations and
Risk-Based Mass Loading Limits,'' revised, April 2012, in the docket
for the final rule.
---------------------------------------------------------------------------

Comments: Assumptions for Reusable Wipes
    Commenters on the 2003 risk screening analysis for the November
2003 proposal stated that EPA did not consider exposures resulting from
solvent-contaminated wipes and laundering processes, other than to
evaluate the sludge and solvent-contaminated wipes disposed in a MSWLF.
Other possible exposure pathways noted were worker exposure at the
laundering facility; the release of constituents not treated at the
POTW; and air emissions from laundries affecting nearby residences.
    Some commenters also noted that EPA neglected to consider
contamination of wipes from the materials that the solvent removes from
the equipment. Information submitted by one commenter indicated that
even after processing by a professional laundering service, cloth shop
towels may contain levels of chemicals (metals) that are potentially
harmful to workers using the wipes. However, another commenter
dismissed this point, stating that claims about residual metals in
clean, laundered shop towels are entirely without merit.
EPA Response: Assumptions for Reusable Wipes
    The purpose of the 2003 risk screening analysis for the November
2003 proposed rule and the 2009 revised risk analysis presented in the
October 2009 NODA was to characterize the potential risk from the
disposal of solvent-contaminated wipes and laundry sludge in landfills.
Therefore, occupational exposures, such as exposures resulting from the
partitioning of solvents to air and wastewater during laundering and
dry cleaning operations, were not

considered. Our analyses assumed that workers are appropriately
protected by regulation and guidance provided by OSHA.\41\
---------------------------------------------------------------------------

    \41\ For example, worker exposures to airborne contaminants are
limited based on 29 CFR 1910.1000 Tables Z-1 and Z-2.
---------------------------------------------------------------------------

    Concerning exposure to residents living in close proximity to
laundering/dry cleaning facilities, given the range of exposures
captured by the modeling scenarios in the 2009 revised risk analysis
presented in the October 2009 NODA, and the fact that ambient air
exposures were not significant, any ambient air impacts from
laundering/dry cleaning operations should be less significant than
those considered under our landfill disposal scenario. The 2009 revised
risk analysis assumed that ambient air exposure could occur as close as
25 meters from the landfill, a fairly conservative assumption. Despite
this, none of the 90th percentile RB-MLLs were based on ambient air
exposures. Indoor air exposures resulting from showering with
contaminated groundwater and groundwater ingestion were found to be the
key exposures considered, and these risks drove the analysis. With
regard to partitioning of solvents to wastewater, any risks associated
with these discharges would be addressed by the CWA, under NPDES
permits or local POTW pretreatment standards, if necessary.
    In response to the possibility of co-contaminants, we first note
that solvent-contaminated wipes that exhibit a characteristic (except
for ignitability) due to constituents other than one of the excluded F-
and corresponding P- and U-listed solvents (e.g., co-contaminant
metals) are not eligible for the conditional exclusions. Similarly,
wipes contaminated with other listed hazardous wastes would not be
eligible for the conditional exclusions. Regarding other possible
contaminants, we note that the F-, P-, and U-code solvent listings are
based on the toxicity and/or ignitability hazards presented by the
specific solvents included in the listing descriptions. The language in
the listings illustrates EPA's concern with the solvent chemicals.
Other potential constituents in the solvent wastes vary widely across
industries, such that it would be exceedingly difficult, if not
impossible, to categorize and evaluate risks associated with these
wastes if we considered all other hazardous constituents and
characteristics. Because of the wide variability in constituents that
might be present in wastes from use of the solvents and the identified
hazards posed by the solvents, we focused our evaluation on the solvent
chemicals themselves. We find that this is the most practical approach
to evaluating risks posed by solvent-contaminated wipes.
    Regarding the potential for laundered towels to contain residual
metals, we note that the study cited by the commenter was limited to
metal contaminants, not listed solvents. As described in the above
paragraph, EPA did not attempt to evaluate possible co-contaminants on
the wipes. The exclusion is for wipes contaminated with F-listed
solvents, not metal-contaminated wipes. The solvent-contaminated wipes
are still subject to the TC for metals, which would help to address any
potential metal residuals in the laundered wipes. In addition, any
residual metals still on the towels after laundering would likely be
tightly bound to the fibers, making any transfer from laundered towels
to workers unlikely.
Comments: Other Aspects of the 2009 Revised Risk Analysis Presented in
the October 2009 NODA
    Commenters were generally supportive of the 2009 revised risk
analysis presented in the October 2009 NODA. However, we received
comments on some aspects of the analysis. Many of the comments
submitted were related to the way EPA calculated the estimated landfill
loading rates (ELLRs) for solvents disposed in landfills; we addressed
these comments as described previously (see comments on the revised
solvent loading calculations above). Comments on other aspects of the
2009 revised risk analysis are described below.
    One commenter stated that EPA should use data for laundry sludge
measured using a leaching test in its risk analysis (i.e., the TCLP).
The commenter also argued that EPA was overly-conservative in not
considering the likelihood that the monitoring of groundwater wells
near the landfill would limit exposure and in the assumptions EPA used
for well locations near landfills. In addition, the commenter provided
results of a survey that indicated a ``majority'' of laundry facilities
send their sludges to lined landfills, arguing that this reflected the
general trend over the past 20 years away from unlined landfills.
    Another commenter generally concluded that EPA's 2009 revised risk
analysis is ``scientifically defensible.'' The commenter suggested that
the use of lined Subtitle D landfills for disposal of solvent-
contaminated wipes and laundry sludge ``would be permissible, but not
required, to adequately protect human health and the environment.''
However, the commenter indicated that a number of input assumptions
used in EPA's 2009 revised risk analysis are unnecessarily
conservative, resulting in significant over-estimation of the risks
posed. In particular, the commenter stated that EPA used population
distribution assumptions to calculate exposure concentrations for both
the groundwater and air pathways that assumed higher population
percentages located closer to a landfill than actually occurs. The
commenter also states that, because exposure concentration is a
function of distance from the source, using the EPA distributions
result in an overestimation of calculated risk.
    The commenter also stated that our modeling underestimated the
effect of biodegradation, noting that this could lower the peak
contaminant concentration to which individuals would be exposed.
Finally, the commenter criticized the Agency's approach in comparing
the ELLRs to the RB-MLLs for the various solvents, which used a
comparison of two upper bound values (i.e., the 90th percentile ELLR
and 90th percentile RB-MLL). The commenter stated that this results in
a level of protectiveness that exceeds EPA's stated goal of ensuring
that 90 percent of the hypothetical individuals living near a landfill
will not be exposed to solvent releases at levels of concern. As an
alternative, the commenter suggested the use of ratios that combine the
90th percentile RB-MLLs and the 50th percentile ELLRs.
EPA Response: Other Aspects of the 2009 Revised Risk Analysis Presented
in the October 2009 NODA
    EPA disagrees with the comments regarding the use of TCLP data from
laundry sludge and finds that using the new landfill model (LFCR)
rather than TCLP leachate data for modeling solvent releases from
disposed solvent-contaminated wipes and sludge presented several
advantages. The landfill model we used captured a broad variety of
conditions needed to back-calculate acceptable levels of solvent
loadings for a national rule. Our approach allowed calculation of
releases to all media, including air. Using this approach, we were able
to consider the potential risk for a range of chemicals based on their
properties and transport characteristics, regardless of whether
empirical release data, such as TCLP, were available. Furthermore, the
TCLP data submitted by the commenter were severely limited (e.g., the
submitted samples were taken in the 1990s, some samples were not
analyzed for the organic constituents of interest, and

there was no supporting QA/QC data provided).
    EPA disagrees that the groundwater modeling scenario we used was
based on overly conservative assumptions. This reasonable groundwater
exposure scenario, developed to be protective of highly exposed
individuals, has been implemented to support various EPA risk analyses,
which have withstood extensive external peer reviews. EPA also
disagrees with the commenter's assumption that, in an unlined landfill
scenario, comprehensive monitoring is being done to assess potential
impacts to groundwater, and that such monitoring would prevent
potential risk. While monitoring is required for many landfills, there
are exceptions to this requirement (e.g., for smaller landfills, as
defined in Sec.  258.1(f)(1)). In any case, protectiveness should not
rely on groundwater monitoring to protect nearby residents from
potential exposures. Rather, our risk analysis seeks to estimate risks
to highly exposed individuals that rely on groundwater sources near
landfills. If we rely on well monitoring, then groundwater releases
might not be detected until aquifers have been contaminated. That
approach would be inconsistent with the preventive intent of RCRA to
prospectively avoid releases into the environment that may threaten
human health and the environment. Therefore, relying on monitoring is
not appropriate in our risk analysis.
    With respect to the issue of landfill and well locations, we note
that these locations can change over time. Therefore, EPA used
probabilistic analyses to incorporate the variability and uncertainty
in the data. Landfill locations for this risk analysis were based on
the locations found in EPA's landfill database. We implicitly assumed
that off-site landfills provide a reasonable representation of the
distribution of MSWLFs across the United States. From this database, we
obtained a sample population of locations and correlated parameters
(e.g., aquifer type, climate center, soil types, and aquifer
temperature) necessary to run the source and fate and transport models.
The commenter's claim that their survey shows that the ``majority'' of
laundry facilities dispose of their sludge in a lined landfill is not
sufficient to demonstrate that there are no potential risks from
disposal in unlined units. Nonetheless, we modeled both an unlined and
composite-lined landfill scenario to assess the full range of potential
risks. The Agency found that disposal in composite-lined landfills was
a necessary condition for the exclusion to adequately protect human
health and the environment.
    With respect to population distributions, we acknowledge that the
2009 revised risk analysis used conservative receptor locations.
However, our analysis does not directly consider population risk;
rather this national-level risk analysis was designed to be protective
of highly exposed individuals. Regarding the groundwater pathway, we
used a probabilistic approach for well placement that was based on
residential well locations taken from surveys of MSWLFs. Similarly for
the air risk evaluation, the specific distances to receptors were
selected to ensure complete coverage in the air estimates, particularly
near the source of the emissions where the greatest impact can be
observed; this analysis was conducted using a conceptual site model
that is plausible anywhere in the contiguous 48 states.
    This approach for receptor location is reasonable for this
national-level analysis. In a supplemental report, one commenter
provided an alternative assessment that evaluated the well distances
with respect to population density surrounding twelve landfills in four
states. However, the commenter's density analysis and the referenced
state regulations are only snapshots of a limited number of existing
landfill scenarios and are not sufficiently representative of potential
exposures to releases from other landfill scenarios throughout the
nation. Landfills are subject to various state requirements (e.g.,
different buffer zones), and twelve landfills in four states are
clearly less representative than the data used by EPA for the nation as
a whole.
    EPA disagrees with the commenter who stated that our modeling
underestimated the effect of biodegradation. The landfill model we used
incorporated biodegradation of the solvents in the landfill using the
available biodegradation data. We also modeled some degradation in
groundwater (i.e., hydrolysis). Some types of transformation processes
in groundwater, such as biodegradation, are more site specific and can
be highly variable. This would be much more difficult to simulate in
groundwater using a generic model such as the EPA CMTP, especially
without extensive biodegradation data on subsurface aquifer conditions
nationwide, which the commenter did not provide. Thus, for this
national-level analysis, we conservatively assumed that these processes
do not occur, and biodegradation was not included in the subsurface
environment beyond the landfill.
    Regarding our comparison of the 90th percentile values of the ELLRs
and RM-MLLs, our analysis was designed to be protective of 90 percent
of hypothetically exposed individuals across all of the landfill sites
in the United States. This is consistent with EPA guidance, which
states that ``For the Agency's purposes, high end risk descriptors are
plausible estimates of the individual risk for those persons at the
upper end of the risk distribution,'' or conceptually, individuals with
``exposure above about the 90th percentile of the population
distribution.'' \42\ While the applied approach is conservative,
comparing the 90th percentiles is appropriate for achieving this goal.
The ELLRs at selected percentiles are analogous to the RB-MLLs in that
they represent a best estimate of the actual value at each percentile.
We disagree with the comparison suggested by the commenter (i.e.,
comparing the central tendency ELLR to the 90th percentile RB-MLL)
because it would not be protective of 90 percent of hypothetically
exposed individuals. Comparing the respective 90th percentiles is
appropriately and reasonably conservative, given the considerable
uncertainty associated with the loading limits.
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    \42\ See ``Guidance for Risk Characterization,'' accessible at
http://www.epa.gov/OSA/spc/2riskchr.htm.
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    Responses to all comments on the calculation of the RB-MLLs used in
the November 2003 proposal and the 2009 revised risk analysis presented
in the October 2009 NODA are provided in the docket.\43\
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    \43\ See the docket for the documents ``Response to Comments on
the Solvent Contaminated Wipes 2003 Screening Risk Analysis'' and
``Response to Comments on the Solvent Contaminated Wipes 2009 Risk
Analysis: Risk-Based Mass Loading Limits.''
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X. How will these regulatory changes be administered and enforced?

A. Applicability of Rules in Authorized States

    Under RCRA section 3006, EPA may authorize qualified states to
administer the RCRA Subtitle C hazardous waste program within the
state. Following authorization, the authorized state program operates
in lieu of the federal regulations. EPA retains enforcement authority
to enforce the authorized state Subtitle C program, although authorized
states have primary enforcement authority. EPA also retains its
authority under sections 3007, 3008, 3013, 3017, and 7003. The
standards and

requirements for state authorization are found at 40 CFR part 271.
    Prior to enactment of the Hazardous and Solid Waste Amendments of
1984 (HSWA), a state with final RCRA authorization administered its
hazardous waste program entirely in lieu of EPA administering the
federal program in that state. EPA did not issue permits for any
facilities in that state, since the state was now authorized to issue
RCRA permits. When new, more stringent federal requirements were
promulgated, the state was obligated to enact equivalent authorities
within specified time frames. However, the new requirements did not
take effect in an authorized state until the state adopted the
equivalent state requirements.
    In contrast, under RCRA section 3006(g) (42 U.S.C. 6926(g)), which
was added by HSWA, new requirements and prohibitions imposed under HSWA
authority take effect in authorized states at the same time that they
take effect in unauthorized states. While states must still adopt HSWA
related provisions as state law to retain final authorization, EPA
implements the HSWA provisions in authorized states, including the
issuance of any permits pertaining to HSWA requirements, until the
state is granted authorization to do so.
    Authorized states are required to modify their programs only when
EPA promulgates federal requirements that are more stringent or broader
in scope than existing federal requirements.\44\ RCRA section 3009
allows states to impose standards more stringent than those in the
federal program (see 40 CFR 271.1). Therefore, authorized states may,
but are not required to, adopt federal regulations, both HSWA and non-
HSWA, that are considered less stringent than previous federal
regulations.
---------------------------------------------------------------------------

    \44\ EPA notes that decisions regarding whether a state rule is
more stringent or broader in scope than the federal program are made
when the Agency authorizes state programs.
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B. Effect on State Authorization

    Today's rule amends the definition of solid waste to conditionally
exclude solvent-contaminated reusable wipes and the definition of
hazardous waste to conditionally exclude solvent-contaminated
disposable wipes. These definitions were promulgated under the
authority of sections 2002, 3001-3010 and 7004 of the Solid Waste
Disposal Act of 1965 (later amended by RCRA and by HSWA). Today's rule
amends the application of the RCRA Subtitle C ``base'' program to
certain wastes and is thus a non-HSWA rule.
    Because, today's conditional exclusions are not HSWA regulations,
today's regulatory provisions are not immediately effective in
authorized states. They are only immediately applicable in those states
and territories that do not have final authorization for the base (non-
HSWA) portion of the RCRA program, including Indian country.
    Today's rule includes requirements and conditions that are less
stringent than those required under the base RCRA hazardous waste
program. Thus, states, except as described below, are not required to
adopt the conditional exclusions. However, the Agency encourages states
to adopt this rule as soon as possible to reduce regulatory burden on
businesses and maximize national consistency, while maintaining
protection of human health and the environment. In addition, if a state
were, through implementation of state waiver authorities or other state
laws, to allow compliance with the provisions of today's rule in
advance of adoption or authorization, EPA would not generally consider
such implementation a concern for purposes of enforcement or state
authorization.
    Of course, states cannot implement requirements that are less
stringent than the federal requirements in today's rule. As we stated
in the November 2003 proposal, the 1994 Shapiro memo established
federal policy with regard to solvent-contaminated wipes that deferred
the determination of their regulatory status to the states and EPA
regions (68 FR 65617). This deferral has resulted in the development of
various state programs for reusable wipes. Today's conditional
exclusion for reusable wipes is generally consistent with many of these
state policies; however, some conditions required by today's final rule
may be more stringent than some existing state programs. As a result,
authorized states whose programs include less stringent requirements
than today's final rule are required to modify their programs to
maintain consistency with the federal program per the provisions of 40
CFR 271.21(e). In addition, any states that delineate their program for
reusable wipes in guidance documents or interpretive letters will need
to promulgate enforceable regulations, as required by 40 CFR 271.7.
Because today's rule is a non-HSWA rule, the current state requirements
remain in place until the state adopts the equivalent to these federal
requirements.

C. Enforcement

    Under today's final rule, reusable wipes are excluded from the
definition of solid waste and disposable wipes are excluded from the
definition of hazardous waste provided certain conditions are met. To
retain the conditional exclusion, each party operating under the
conditional exclusion is responsible for ensuring that all the
conditions in the final rule are met. Failure to maintain all of the
required conditions at all times will result in loss of the exclusion.
Facilities taking advantage of the conditional exclusion that fail to
meet one or more of the conditions may be subject to enforcement
action, and the solvent-contaminated wipes will be considered to be
hazardous waste from the point of their generation (i.e., from the
point when the generator finished using them). EPA could choose to
bring an enforcement action under RCRA section 3008(a) for violations
of the hazardous waste requirements. States could choose to enforce for
violations of state hazardous waste requirements under state
authorities.
    As with any violation, EPA and authorized states have enforcement
mechanisms available that range in severity. In addition, EPA and
authorized states have flexibility in applying these mechanisms to the
various responsible parties as appropriate to the specific
circumstances. Some of the enforcement mechanisms include sending a
notice of violation, ordering that the situation be remedied, or
assessing fines or other penalties as appropriate.
    Generators, transporters, laundries, dry cleaners, disposal,
combustion, or other handling facilities claiming the conditional
exclusions must be able to demonstrate to the appropriate regulatory
agency that the applicable conditions are being met. In an enforcement
action, the facility claiming the conditional exclusion bears the
burden of proof pursuant to 40 CFR 261.2(f), to demonstrate conformance
with the conditions specified in the regulation.
    Additionally, the conditional exclusions in today's rule do not
affect the obligation to promptly respond to and remediate any releases
of solvents and wipes managed within the conditional exclusion. If a
hazardous solvent is spilled or released, then the solvent would be
discarded. Any management of the released material not in compliance
with applicable federal and state hazardous waste requirements could
result in an enforcement action. For example, a person who spilled or

otherwise released a hazardous solvent, and failed to immediately clean
it up, could potentially be subject to enforcement for illegal disposal
of the hazardous waste. The hazardous waste could also potentially be
addressed through enforcement orders, such as orders under RCRA
sections 3013 and 7003.

XI. Administrative Requirements for This Rulemaking

A. Executive Order 12866--Regulatory Planning and Review and Executive
Order 13563--Improving Regulation and Regulatory Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
action is a ``significant regulatory action'' because it raises novel
legal or policy issues under section 3(f)(4) of Executive Order 12866.
Accordingly, EPA submitted this action to the Office of Management and
Budget (OMB) for review under Executive Orders 12866 and 13563 (76 FR
3821, January 21, 2011) and any changes made in response to OMB
recommendations have been documented in the docket for this action.
    In addition, EPA prepared an analysis of the potential costs and
benefits associated with this action. This analysis is contained in
``Regulatory Impact Analysis for Conditional Exclusions from Solid and