Thursday
November 19, 1998
Part IV
Environmental
Protection Agency
40 CFR Part 261
Hazardous Waste Management System:
Identification and Listing of Hazardous
Waste, Solvents; Final Rule
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64372 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Part 261
[SWH-FRL-6185-3]
RIN 2050-AD84
Hazardous Waste Management
System: Identification and Listing of
Hazardous Waste Solvents
AGENCY: Environmental Protection
Agency.
ACTION: Final decision.
SUMMARY: The U.S. Environmental
Protection Agency (EPA) is issuing a
final decision not to list wastes
generated from the use of 14 chemicals
as solvents as hazardous under the
Resource Conservation and Recovery
Act (RCRA). The determinations in this
rule are limited to specific solvent
wastes. This rule is a determination
only that the solvent wastes considered
will not be added to the list of
hazardous wastes and is not a
determination that the underlying
chemicals are nontoxic in all
circumstances in which they are used or
discarded.
DATES: Today's final decision will
become effective on December 21, 1998.
ADDRESSES: Supporting materials are
available for public viewing and
photocopying in the RCRA Information
Center (RIC), located at Crystal Gateway
I. First Floor. 1235 Jefferson Davis
Highway. Arlington, VA. The Docket
Identification Number is F-98-SLDF-
FFFFF. The RIC is open from 9:00 a.m.
to 4:00 p.m., Monday through Friday,
excluding federal holidays. To review
docket materials, it is recommended
that the public make an appointment by
calling (703) 603-9230. The public may
copy a maximum of 100 pages from any
regulatory docket at no charge.
Additional copies cost S0.15/page. The
index and some supporting materials
are available electronically. See the FOR
FURTHER INFORMATION CONTACT section
for information on accessing them.
FOR FURTHER INFORMATION CONTACT: The
RCRA/Superfund Hotline, toll-free, at
(800) 424-9346 or at (703) 920-9810.
The TDD Hotline number is (800) 553-
7672 (toll-free) or (703) 486-3323 in the
Washington, DC metropolitan area.
For technical information on the
RCRA hazardous waste listings, contact
Ron Josephson or Robert Kayser, Office
of Solid Waste (5304W), U.S.
Environmental Protection Agency, 401
M Str.eet, SW, Washington, DC 20460.
The telephone number is (703) 308-
8890.
SUPPLEMENTARY INFORMATION : There are
no regulated entities as a result of this
action.
The index and the supporting
materials are available on the Internet:
Follow these instructions to access the
information electronically:
WWW: http://www.epa.gov/epaoswer/
hazwaste.htm#id
FTP: ftp.epa.gov
Login: anonymous
Password: your Internet address
Files are located in /pub/oswer
The contents of the preamble to this
final rule are listed in the following
outline:
I. Legal Authority and Background
A. Statutory and Regulatory Authorities
B. Existing Solvent Listings and the
Regulatory Definition of Solvent
n. Summary of Proposed Rule
A. Determinations Not to List Solvent
Wastes as Hazardous Waste
B. Summary of Risk Assessment
Supporting the Proposed Rule
m. Peer Review of Calculated f oxicological
Benchmarks
IV. Summary of Response to Comments and
Rationale for Final Rule
A. Data Collection
1. Representativeness of Industry
Characterization
2. Engineering Site Visit Reports
B. Methodology
1. Definition of "Solvent'
, 2. Lack of Sampling and Analysis
3. Consistency of Methodology With Other
Listing Determinations
4. Plausible Mismanagement Scenarios
C. Risk Assessment
1. Surface Impoundments
2. Tank-Based Management of Wastes
3. Multiple Solvents
4. Comparison with HWIR Exit Levels
5. Environmental Damage Incidents
6. Spills, Leaks, and Overflows
7. Non-Aqueous Phase Liquids
8. Risk Modeling Parameters
9. Comparison with Results of Air
Characteristic Study
D. Listing Determinations
1. General Comments
2. Sufficient Regulation of Solvents
3. Waste-Specific Rationales and Response
to Specific Comments
V. Regulatory Requirements
A. Regulatory Impact Analysis Pursuant to
Executive Order 12866
B. Regulatory Flexibility
C. Unfunded Mandates Reform Act
D. Executive Order 12875: Enhancing
Intergovernmental Partnership
E. Executive Order 13045: Protection of
Children from Environmental Health
Risks and Safety Risks
F. Environmental Justice E.O. 12898
G. Paperwork Reduction Act
H. National Technology Transfer and
Advancement Act
I. Executive Order 13084: Consultation and
Coordination with Indian Tribal
Governments
J. Congressional Review Act
I. Legal Authority and Background
A. Statutory and Regulatory Authorities
The Environmental Protection Agency
(EPA) conducted this investigation and
listing determination under the
authority of sections 2002(a), 3001 (a),
(b) and (e)(2) of the Solid Waste
Disposal Act (42 U.S.C. 6912(a), and
692 l(b) and (e)(2)), as amended by
various other laws, the most
comprehensive of which was the
Hazardous and Solid Waste
Amendments (HSWA) of 1984. These
statutes are commonly referred to as the
Resource Conservation and Recovery
Act (RCRA) and are codified at Volume
42 of the United States Code (U.S.C.),
sections 6901 to 6992 (k).
Section 3001(a) of RCRA, 42 U.S.C.
6921 (a), requires EPA to promulgate
criteria for identifying characteristics of
hazardous wastes and for listing
hazardous wastes. Section 300 l(b) of
RCRA requires EPA to promulgate
regulations, based on these criteria,
identifying and listing hazardous wastes
which shall be subject to the
requirements of the Act. Section 1004(5)
of RCRA, 42 U.S.C. 6903(5), defines the
term "hazardous waste." There are two
types of hazardous waste. First,
hazardous wastes are those solid wastes
which may cause or significantly
contribute to an increase in mortality,
serious irreversible illness, or
incapacitating reversible illness.
Second, hazardous wastes are those
solid wastes which may pose a
substantial present or potential hazard
to human health or the environment
when improperly managed. Id.
EPA's regulations establishing criteria
for listing hazardous wastes are codified
at Title 40 of the Code of Federal
Regulations (CFR) 261.11 (40 CFR
261.11). Section 261.11 presents three
criteria by which EPA identifies wastes
as hazardous.
First, solid wastes may be classified as
"characteristic" wastes if they exhibit
any of the characteristics of hazardous
waste identified at 40 CFR 261.21-24
(i.e., ignitability, corrosivity. reactivity,
ortoxicity).
Second, solid wastes may be listed as
acutely hazardous if they are fatal to
humans at low doses, lethal in animal
studies at particular doses designated in
the regulation, or otherwise capable of
causing or significantly contributing to
an increase in serious illness.
Third, solid wastes may be listed as
hazardous if they contain any of the
toxic constituents identified in
Appendix VIII of 40 CFR part 261 and
the Agency concludes, after considering
the eleven factors enumerated in 40 CFR
261.11 (a) (3), that the waste is capable of
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posing a substantial present or potential
hazard to human health or the
environment when improperly
managed. A substance is listed in
Appendix VIII if it has been shown in
scientific studies to have toxic,
carcinogenic, mutagenic, or teratogenic
effects on humans or other life forms.
Today's listing determination has been
made pursuant to this third set of
criteria.
As part of its regulations
implementing section 300 l(b) of RCRA,
EPA published a list of hazardous
wastes that includes hazardous wastes
generated from nonspecific sources (F-
wastes) and a list of hazardous wastes
from specific sources (K-wastes). These
lists, published at 40 CFR 261.31 and
261.32, respectively, have been
amended several times.
Persons who generate, transport, treat,
store, or dispose of wastes listed as
hazardous must do so subject to Federal
requirements under RCRA. Facilities
that must meet the hazardous waste
management requirements, including
the need to obtain permits to manage
hazardous wastes, are commonly
referred to as RCRA Subtitle C facilities.
EPA standards and procedural
regulations implementing Subtitle C are
found generally at 40 CFR parts 260
through 279.
Solid wastes that are not hazardous
wastes may be disposed of at facilities
that are overseen by State and local
governments. These facilities are
referred to as RCRA Subtitle D facilities.
EPA regulations affecting Subtitle D
facilities are found generally at 40 CFR
parts 240 through 247, and parts 255
through 258.
Section 3001 (e) (2) of RCRA requires
EPA to determine whether to list as
hazardous several specified wastes,
including solvent wastes. The
Environmental Defense Fund (EDF) and
EPA entered into a consent decree to
resolve issues raised in a civil action
brought by EDF (EDFv. Browner, Civ.
No. 89-0598 (D.D.C.)) in which the
Agency agreed, among other things, to a
schedule for making a listing
determination on spent solvents. This
listing determination is to consider
spent solvents, still bottoms from the
recovery of these solvents,, and spent
solvent mixtures when the following
chemicals are used as solvents: cumene,
phenol, isophorone, acetonitrile,
furfural, epichlorohydrin, methyl
chloride, ethylene dibromide, benzyl
chloride, p-dichlorobenzene, 2-
methoxyethanol, 2-methoxyethanol
acetate, 2-ethoxyethanol acetate, and
cyclohexanol.
For an additional set of seven
solvents, EPA agreed to conduct a study
and issue a final report by August 30,
1996. This study, which EPA completed
on August 22, 1996, discusses the
wastes associated with the use of the
materials as solvents, the toxicity of the
wastes, and a description of the
management practices for the wastes.
Solvent uses are found throughout
various industries and, thus, would fall
under the category of wastes from
nonspecific sources (F-wastes) if listed
in 40 CFR 261.31. In fact, wastes
designated F001 through F005 are
various wastes from solvent uses of a
number of chemicals. In today's action,
EPA has decided not to amend 40 CFR
261.31 to add wastes generated during
the use of the 14 chemicals of concern
as solvents.
EPA emphasizes that the
determination not to list these wastes
only means that the Agency has found
it is not appropriate to list as hazardous
the wastes across broad industry
categories that could result from solvent
uses of the 14 chemicals. As will be
more fully explained below, EPA did
not find that solvent uses for these
chemicals, in general, produce
hazardous wastes that require listing.
Many of the wastes examined are
hazardous already because they are
characteristic wastes under 40 CFR part
261, subpart C, or contain other solvent
wastes currently listed as hazardous. In
addition, some of the chemicals may
produce wastes that are hazardous when
used in ways other than as solvents,
perhaps as catalysts, feedstocks or other
uses in chemical manufacturing
processes. Solvents use simply does not
constitute an appropriate way to
designate these chemicals as a
hazardous waste category under RCRA
for wastes from nonspecific sources.
Particular industrial wastes from these
chemicals might be hazardous, but such
wastes were not examined in this
determination.
B. Existing Solvent Listings and the
Regulatory Definition of Solvent
Five hazardous waste listings for
specific solvents have been promulgated
to date: F001, F002, F003, F004, and
F005. These are found at 40 CFR 261.31.
Today's decision applies the same
criteria for defining solvent wastes as
are applied to these existing solvents
listings. These criteria are explained in
the Federal Register of December 31,
1985 (50 FR 53316) and are also
consistent with the requirements of the
EDF Consent Decree.
The December 1985 document
amended the solvent listings to include
spent solvent mixtures when the
solvent, before it is used, contains 10
percent or more of total listed solvents.
The original listing included only the
technical grade, practical grade or pure
form of the solvents when used. This
threshold level was considered by the
Agency to be well below the minimum
solvent concentration typically used in
solvent formulations and was designed
to bring the majority of listed solvent
mixtures used in commerce into the
hazardous waste management system,
while excluding dilute mixtures or de
minimis concentrations.
In addition, the document issued
several clarifications to the original
listings. First, the listings apply to
"spent" solvents—those that are no
longer fit for use without being
regenerated, reclaimed, or otherwise
processed. (See 40 CFR 261.1(c) (1) and
(4); 261.2(c) (3) and (e)). Second, the
listings cover only those solvents used
for their solvent properties—"to
solubilize (dissolve) or mobilize other
constituents." These include solvents
used in degreasing, cleaning, fabric
scouring, as diluents, extractants,
reaction and synthesis media. The
document stated that the listings do not
cover wastes from the processing of
products where a chemical that might
be used as a solvent is, instead, used as
a reactant or where a chemical is used
as a solvent only as an ingredient in the
formulation of a commercial chemical.
This latter category would include
chemicals used as a solvent in paint
formulations to dissolve the paint itself.
These uses do not generate "spent
solvent" wastes. The wastes of concern
for these products would be the
production process wastes or wastes
from the use of the product, not the
solvent itself.
This approach is also consistent with
the requirements of the EDF Consent
Decree. This is because the consent
decree identifies a subset of solvent
wastes that are potential candidates for
listing and specifies that the listing
determination applies to "spent
solvents," a term that tracks the
language of the existing listings.
Moreover, this approach had been the
longstanding approach of the Agency to
dealing with solvent listings at the time
the Consent Decree was negotiated and
should be interpreted as representing
the understanding of the parties.
This approach, whereby EPA has
limited the scope of this rulemaking
through this focused definition of
solvents subject to the listing, is a
reasonable interpretation of RCRA and
is consistent with EPA's historical
treatment of solvent listing descriptions.
Use of the definition has allowed the
Agency to place reasonable limits on the
scope of its listing investigation for this
rulemaking. RCRA3001(e)(2) directs
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EPA to make a listing determination on
"solvents," but provides no further
direction on the meaning of that term.
EPA, therefore, has the discretion to
reasonably define the scope of the
listing determination. Given the
ubiquity of solvents, the great variety of
uses and the huge differences in the
composition of the waste streams, EPA
could not gather the evidence to list
"solvent wastes" as a general category.
Under the Agency's regulations at 40
CFR 261.11 (b), wastes may be listed as
a category if they are "typically or
frequently" hazardous. EPA could make
no such findings for "solvent" wastes in
general and, therefore, has reasonably
focused its investigation and listing
decision.
As noted above, the existing solvent
listings are limited to spent solvent
mixtures when the solvent, before it is
used, contains 10 percent or more of
total listed solvents. While wastes from
this use threshold were the primary
focus of today's listing determination,
EPA also considered in its evaluations
the few solvent uses that were reported
to be below the 10 percent threshold.
In a previous proposed hazardous
waste listing for wastes from the
production of dyes and pigments (59 FR
66072, December 22, 1994) EPA
presented the general approach the
Agency uses for determining whether to
list a waste as hazardous pursuant to 40
CFR 261.11 (a) (3). The discussion
focused on the selection of waste
management scenarios used in assessing
risk and the use of information on risk
levels in making listing determinations.
This approach was further developed in
EPA's listing for petroleum refining
process wastes (proposed rule published
at 60 FR 57747, November 20, 1995;
final rule published at 63 FR 42110,
August 6, 1988). EPA is employing the
same general approach in this final
rulemaking. Readers are referred to
these documents for a description of
EPA's listing policy. Also, section II.C.2.
of the proposed rule, "Risk
Assessment," contains a discussion of
how elements of EPA's listing policy
were applied in today's listing
determination.
The following section contains a
summary of the methodology used to
arrive at the no-list determinations in
today's document. For more details on
this methodology, see the proposed rule,
background document, and the response
to comments document in the docket.
EC. Summary of Proposed Rule
A. Determinations Not To List Solvent
Wastes as Hazardous Waste
EPA proposed the decision not to list
the spent solvent wastes from the 14
chemicals noted above on August 14,
1996 (61 FR 42318). The Agency
determined that these wastes did not
meet the criteria for listing set out in 40
CFR 261.11. The proposed rule
presented the waste characterization,
waste management, mobility,
persistence, and risk assessment data
that were the bases for the Agency's
proposed decision not to list these
wastes as hazardous. Further details of
EPA's approach are presented in the
Hazardous Waste Listing Determination
Background Document for Solvents
(hereafter known as "Listing
Background Document") in the docket
for the proposal to today's rule.
As explained in section II.B of the
proposed rule, spent solvents differ
from other listed wastes among EPA's
waste listings in that the solvents are
used in manufacturing and allied
processes rather than being the
principal waste streams generated by
manufacturing processes. In order to
characterize industrial solvent use, the
Agency sent out almost 1,500
preliminary questionnaires to cover the
21 total chemicals (14 from the listing
determination and seven from the
study). An additional 60 facilities were
surveyed on their use of these chemicals
as solvents through the chlorinated
aliphatics industry survey. EPA then
sent out a full RCRA section 3007
survey to facilities using greater than a
combined total of 1,200 kilograms of all
the chemicals-sf concern.
The Agency consulted various
literature and reference sources, such as
Chemical Abstracts, general reference
books, the Agency's Toxic Release
Inventory (TRI) compiled under section
313 of the Emergency Planning and the
Right-to-Know Act (EPCRA), databases
compiled for various EPA programs
dealing with air and water pollution,
and information available from trade
associations. Of the 14 chemicals
involved in the listing determination, 11
were on the TRI. Use of the literature.
Chemical Abstracts, TRI, and other EPA
databases allowed the Agency to focus
on the industries that actually use these
chemicals as solvents. In addition, many
of these sources gave strong indications
as to when major uses of a chemical
were not as a solvent.
Once the Agency narrowed down the
potential solvent-using industries, the
Agency developed a list of facilities to
survey about their solvent use. These
facility names and addresses were
obtained again from a variety of sources,
including TRI, trade associations, and
other Agency media program sources.
The Agency sent a short ("preliminary")
questionnaire to approximately 1,500
facilities inquiring about uses of any of
the 14 listing determination chemicals
as solvents and the quantities used.
The Agency used the preliminary
questionnaire data to develop the large
questionnaire mailing list and to
organize site visits. The Agency also
made several hundred confirmatory
telephone calls to determine that
reported information was correct. The
data from the preliminary questionnaire
showed the Agency several distinct
patterns of solvent use: facilities that
use large amounts of any of these
chemicals as solvent, those that use
small quantities as solvents, and those
that use none of the chemicals as
solvents. The Agency found that a
solvent use quantity of 100 kg per
month, or 1,200 kg per year, provided a
mathematically convenient separation
of those facilities who use large amounts
of solvent and those who use very little
and provided an indication as to which
facilities were likely to be large quantity
generators of hazardous waste based on
use of these chemicals as solvents.
Based on careful analysis of the data,
the Agency identified likely large-scale
users of these chemicals as solvents.
The Agency then developed the large
questionnaire. This questionnaire
reconfirmed data on solvent use and
requested detailed information on a
facility's solvent-using processes, waste
generation, waste management, and
waste minimization activities. The
Agency sent this questionnaire to
approximately 150 facilities that
indicated to the Agency through the
preliminary questionnaire that
significant solvent uses of these
chemicals exist. The data obtained from
the questionnaire were applied to the
risk assessment process described in
today's document as well as the
preparation of the background
document.
To summarize the results, 4 of the 14
chemicals showed no use as a solvent.
The remaining 10 chemicals were
analyzed in the Agency's risk
assessment based on solvent uses found
by the Agency. For the 10 chemicals of
the required listing determination for
which there were solvent uses
(acetonitrile, 2-ethoxyethanol acetate, 2-
methoxyethanol, 2-methoxyethanol
acetate, cyclohexanol, cumene, phenol,
furfural, isophorone, and methyl
chloride), EPA found that the
management of residuals from the use of
these chemicals as solvents did not pose
a risk to human health or the
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environment under the plausible
management scenarios assessed. The
data used as the bases for these
determinations were presented in
sections II.D through II.M of the
proposed rule (61 FR 42327). Detailed
information is also presented in the
background documents supporting the
proposed rule (RCRA Docket number F-
96-SLDP-FFFFF).
Specifically, none of the solvents
satisfy the criteria for listing in 40 CFR
261.11 (a) (3). For acetonitrile, 2-
methoxyethanol, and methyl chloride,
while risk analyses indicated some
potential risk from air releases of these
chemicals from onsite accumulation in
open tanks, EPA believes this risk
would not be significant because most,
or in some cases all, of the
nonwastewater residuals are already
regulated as hazardous waste. For
phenol, 2-ethoxyethanol acetate,
furfural, cumene, cyclohexanol,
isophorone, and 2-methoxyethanol
acetate, the risk estimates indicated that
spent solvent residuals from the use of
these chemicals as solvents do not pose
a substantial risk or potential hazard to
human health or the environment
through the plausible management
scenarios and pathways assessed.
For the remaining four chemicals
subject to the required listing
determination in the EDF Consent
Decree (1,4-dichlorobenzene, benzyl
chloride, epichlorohydrin, and ethylene
dibromide), EPA proposed not to list
residuals from their use as solvents,
because the data collected by EPA
showed that these chemicals are
extremely unlikely to be used as
solvents. One of the chemicals (p-
dichlorobenzene) is a solid at room
temperature, and the other three (benzyl
chloride, epichlorohydrin, and ethylene
dibromide) are relatively reactive
chemicals not well suited to solvent use.
EPA's information showed that the very
limited solvent use reported for these
four chemicals is linked to bench-scale
or experimental laboratory settings, and
no significant solvent uses were found.
For more detail see sections II.N through
II.Q of the proposed rule (61 FR 42347)
and background documents supporting
the proposed rule (RCRA Docket
number F-96-SLDP-FFFFF).
B. Summary of Risk Assessment
Supporting the Proposed Rule
As described in detail in the proposed
rule (see 61 FR 42322-42327), EPA
carried out various analyses to
determine the potential risk that might
arise from the disposal of the spent
solvent wastes under study. In carrying
out the modeling for these assessments,
EPA used available data it collected
from industries using these solvents.
The Agency used information gathered
in the RCRA 3007 Questionnaires and
site visits related to the waste
characteristics, waste management
practices, and potential pathways for
release and exposure. EPA used other
generic input parameters to fate and
transport models to estimate the risk a
waste might present under management
scenarios known to occur. The data
used in the modeling efforts included
the concentrations and toxicity of the
solvent constituents in the waste, the
mobility and fate of such constituents in
different disposal scenarios, likely
exposure routes under these scenarios,
and the location of receptors that might
be exposed.
The levels of receptor exposure
estimated from modeling were
compared with toxicological
benchmarks to evaluate the potential
health impacts. For noncarcinogenic
constituents, EPA used reference doses
for ingestion exposure (RfDs) and
reference concentrations for inhalation
exposure (RfCs); these are measures of
acceptable daily intakes for a specific
chemical. To assess the hazard to a
hypothetical individual, EPA used
hazard quotients (HQs). An HQ is the
ratio of the modeled exposure (or dose)
received compared with-the acceptable
daily dose (the RfC or RED). An HQ
above one indicates that exposures may
occur above acceptable levels. For
carcinogenic constituents, EPA
compared exposure levels to
carcinogenic potency estimates
(carcinogenic slope factors, or CSFs) to
calculate specific risk levels. The
carcinogenic risks results are expressed
in terms of individual risk, reflecting the
additional incidence of cancer that may
occur in an exposed population. For
example, a risk of 1 x 10~5 (which will
be presented in this document as IE-OS)
corresponds to a probability of one
additional case of cancer for every
100,000 people exposed.
EPA used verified RfDs, RfCs, or CSFs
when available in EPA's Integrated Risk
Assessment Information System (IRIS).
IRIS, which represents a consensus
opinion of EPA health scientists, is a
database of human health effects that
may result from exposure to various
substances found in the environment.
For the chemicals that did not have
complete verified IRIS data available (2-
methoxyethanol acetate, cyclohexanol,
phenol, and isophorone), EPA
calculated provisional values when
needed for use in the listing
determinations.
EPA performed a number of different
types of risk analyses. First the Agency
completed a "bounding analysis" to
screen out solvent wastes from further
consideration. In this analysis, the key
input parameters were set to their
"high-end" values (typically the 90th
percentile point on the distribution of
values available for each parameter). For
solvent wastes that did not "bound
out," EPA then ran a high-end
"deterministic" sensitivity analysis to
determine which high-end input
parameters result in the greatest risk.
EPA calculated risks for all
combinations when the most sensitive
parameters were set at high-end values
and then used the highest "high-end"
risk. In this way, EPA attempted to
estimate "high-end" risks that were
somewhere above the 90th percentila,
i.e., the risks would be below this level
for at least 90% of the population at
risk. EPA also calculated "central
tendency" risks, which correspond to
the risk when all input parameters were
set at their median value.
Critical decisions for risk assessment
include EPA's determination regarding
which waste management scenarios to
model and how to use the information
on waste volumes and solvent
concentrations disposed as modeling
input. The Agency's modeling focused
primarily on potential releases from
wastes managed in aerated tanks, stored
in open tanks, undergoing thermal
treatment, and managed in surface
impoundments. Modeling was based on
the information EPA collected from
facilities, including quantities of wastes
managed. For each management
scenario, EPA evaluated the full range of
direct and indirect pathways through
which the solvents could affect human
health or the environment. Based on the
physical and chemical properties of the
constituents of concern and plausible
management practices, certain routes of
exposure for some scenarios were not
considered to pose threats and were not
further evaluated.
In general, solvent wastes fell in
several major categories. Wastewaters
were typically diluted aqueous wastes
that are managed in a biological
treatment system (usually in tanks).,
Nonwastewaters includes two
subcategories. These include: (1) wastes
with high levels of solvents or other
organic chemicals, which were sent for
thermal treatment in incinerators,
industrial boilers, or fuel blenders, and
(2) treatment residuals, such as
wastewater treatment sludges or
incinerator ash, which contained
negligible levels of solvents.
EPA modeled storage in an open tank
and thermal treatment for
nonwastewater spent solvent residuals
from use of all of the ten solvents. EPA
modeled wastewater treatment in
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64376 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
aerated tanks for wastewater residuals
resulting from the use of acetonitrile, 2-
methoxyethanol, 2-ethoxyethanol
acetate, phenol, furfural, and cumene as
solvents.
The surface impoundment scenario
was assessed for five of the solvents;
acetonitrile, phenol, cumene, furfural,
and methyl chloride. For acetonitrile
and cumene, the headworks
concentrations (i.e., the concentrations
after the spent solvent was mixed with
other wastewaters at the headworks of
the wastewater treatment system)
potentially discharged to surface
impoundment were below the health-
based levels for these constituents, and
thus were not evaluated further. For
phenol, three wastewaters with spent
phenol were reported to be managed in
surface impoundments that are part of a
wastewater treatment train. In two of
these cases, the phenol concentration
was below the drinking water health-
based level after mixing at the
headworks. prior to reaching the surface
Impoundment. In the third case the
stream had levels ranging above the
health-based level: however this level is
expected to be efficiently treated by the
activated sludge, such that little phenol
would be available for release to
groundwater. For methyl chloride, EPA
modeled air releases from treatment in
a surface impoundment, but not the
groundwater pathway because the
impoundment was a permitted
hazardous waste management unit. (As
described below, the unit treating
methyl chloride wastes was unique due
to the highly specialized nature of this
solvent use). EPA modeled treatment in
a surface impoundment for furfural;
however, bounding analyses showed no
significant risks via air or groundwater
pathways. The solvent use of the
chemicals modeled in surface
impoundments are very specialized.
This means that they have properties
that only allow very particular solvent
uses in a very narrow set of
circumstances and only for some
industries, or even for only one. For
example, methyl chloride is a gas at
room temperature, which severely limits
its utility as a solvent. The only
significant solvent use for this chemical
is as a solvent in the polymerization of
butyl rubber, during which methyl
chloride is passed through aluminum
chloride to form and solubilize the
catalyst used. The chemical's special
ability to generate such a catalyst
solution is why it is used. Similarly, by
far the largest solvent uses of furfural
and phenol are in the extraction of a
high molecular weight oil (lubrication
oil) during petroleum refining; these
chemicals have very limited solvent
uses outside the petroleum industry.
Therefore, EPA has a high degree of
confidence that the concentrations of
chemicals in the streams flowing into
surface impoundments studied in this
listing determination are representative
of the universe of such uses and
possible exposure scenarios.
The landfill scenario was initially
assessed for acetonitrile, methyl
chloride, cumene, and cyclohexanol,
but not modeled for spent solvent
residuals from any of these solvents
because the concentrations in the wastes
were "trace" or "negligible." Further
general background for the risk
assessment is provided in the preamble
to the proposed rule (see 61 FR 42318).
III. Peer Review of Calculated
Toxicological Benchmarks
Standard inhalation toxicological
benchmarks were not available to EPA
for four of the solvents when the Agency
was conducting the risk assessment for
the proposed rule. The Agency therefore
calculated values specifically for the
rule. EPA has labeled these toxicological
benchmarks "provisional RfCs" to
clearly differentiate them from the
Agency consensus values listed on IRIS.
During the comment period, EPA
solicited peer review of these calculated
risk values. The peer review reports and
the complete Agency response to the
reports are in the docket for this
rulemaking.
In response to comments received in
the peer review reports, EPA adjusted
three of the provisional toxicological
benchmarks used for this risk
assessment. The changes are shown in
Table 1.
TABLE 1 .—CHANGES IN TOXICOLOGICAL BENCHMARKS FOR AIR PATHWAY
Solvent
Cyclohexanol
Phenol .. ,
Isophorone
NOAEL1 (mg/m3)
0.06
.19
37(LOAEL)2
Previous provi-
sional toxi-
cological
benchmark
(mg/m3)
Q00006
Q019
0.0037
New provisional
toxicological
benchmark
(mg/m3)
0.00002
0.006
0.012
1 No observed adverse effect level.
2 Lowest observed adverse effect level.
The new benchmarks for
cyclohexanol and phenol reflect
additional uncertainty factors to account
for insufficient toxicity databases. The
benchmark for isophorone reflects a
reduction in overall uncertainty factors
to reflect Agency guidance limiting such
factors to a total of 3,000. Full
documentation of the methodology for
developing these benchmarks is in the
docket for this rulemaking.
In addition, the toxicological values
for cumene were changed on IRIS
during the comment period. The RfD
(for noncancer ingestion risks) was
changed from 0.04 mg/kg/day to 0.1 mg/
kg/day. The RfC (for noncancer
inhalation risks) was changed from
0.009 mg/m3 to 0.4 mg/m3. These
changes both reflect greater tolerance for
cumene than the previous benchmarks
and thus have no impact on EPA's
decision not to list wastes derived from
the use of this chemical as a solvent.
The Agency has employed these
revised "provisional RfCs" for all the
updated risk assessments involving
these solvents for the final rule. In
addition, the Agency has re-estimated
risks assessed for the proposed rule
using these new benchmarks.
Documentation of these re-estimations
appears in the supplemental risk
assessment background document to
this final rule. The final risk estimates
for all the solvents are shown in Table
3 of this preamble.
In all cases the changes to the
toxicological values do not have any
significant impact on EPA's risk results,
nor do the changes affect any listing
decisions. The solvent wastes for the
chemicals examined still do not pose
significant risks, and thus, these
analyses confirm the proposed decisions
not to list these wastes.
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IV. Summary of Response to Comments
and Rationale for Final Rule
The Agency is responding in this
preamble to the most significant
comments received in response to the
document of August 14, 1996, 61 FR
42318. Other comments received by the
Agency are addressed in the document
entitled Hazardous Waste Listing
Determination: Spent Solvents,
Response to Comments (hereafter
known as Response to Comments
Document) that is available in the
docket associated with this rulemaking.
The Agency is responding to a variety
of comments concerning data collection,
methodology, risk assessment scenarios,
and issues specific to each chemical in
this listing determination. The
responses, while touching many specific
aspects of the listing determination
effort, involve three major themes:
• The Agency used a very thorough
survey, which characterized the risks of
the spent solvents. The Agency
researched various potential
applications of these chemicals as
solvents and found that solvent uses are
confined to a limited set of industrial
applications. Data collected from the
questionnaires confirmed the general
lack of wide solvent use, and are
consistent with EPA's search of the
literature. These findings allowed the
Agency to consider the applicable waste
generation and management practices,
and define plausible management
scenarios for use in evaluating potential
risks associated with these solvent
wastes.
• Facilities use the solvents for
specific purposes that vary by the
desired process. Some of the solvents in
this listing determination have different
applications over certain industries (i.e.,
acetonitrile). Even within one industry,
the primary commonality among the
processes is-the solvent constituent
itself. Other solvents were used in very
limited ways and their primary uses
were highly specialized (e.g., furfural).
However, even for solvents with
specialized uses, other minor uses were
typically reported for different
industries and processes. The resulting
potential variability in waste
compositions led the Agency to focus its
efforts on evaluating the solvent
constituent itself. The Agency believes
it has captured the risks that arise from
the solvents themselves, and that this is
a reasonable approach to fulfilling its
listing determination obligations.
• Little to no benefit would accrue
from regulating these wastes because
many are already regulated and treated
as hazardous wastes. These solvent
wastes, particularly nonwastewaters
with a high organic content, are
characteristically hazardous or mixed
with other listed wastes, and are
generally thermally treated. Other
nonwastewaters, such as wastewater
treatment sludges or filter media, do not
contain measurable levels of the solvent
constituents, and thus present no
significant risks.
A. Data Collection
1. Representativeness of Industry
Characterization
One comment argues that EPA cannot
fully characterize industry solvent
management practices because the
facilities that may be affected are too
numerous to predict and specifically
identify. Therefore, the Agency should
project standard mismanagement
scenarios in order to examine the full
range of actual and potential waste
management practices applicable to the
wastes. This is the only way the Agency
can discharge its mandate to protect
human health and the environment.
In response, EPA disagrees that it is
not possible to predict and identify, as
a practical matter, the facilities that may
be affected. It is possible and
appropriate to do so and EPA has, in
fact, accomplished that purpose, as
summarized below and explained more
fully in the Response to Comments
Document. The Agency outlined the
general approach to the data collection
process in the proposal (61 FR 42321-
42322). To summarize, the Agency
began collecting data on all 14
chemicals involved in the listing
determination (plus the seven in the
Solvents Study) as a means of collecting
background information on these
chemicals. The Agency identified
solvent uses through cross-referencing
SIC codes in known and suspected
process industries with data found in
the TRI, Office of Water facility lists,
and many other data sources. The
Agency used many different facility
address lists to create a list of potential
solvent-using facilities.
The sources used by the Agency
provide a comprehensive view of the
types of uses of these chemicals as
solvents and the quantities used. The
Agency identified industries using the
14 chemicals as solvents by conducting
literature searches including Chemical
Abstracts, the Chemical Engineering
Handbook, the Industrial Solvents
Handbook, and the SRI Chemical
Economics Handbook. As today's
document and the associated
background documents explain, the
process was a logical, iterative, step-by-
step process. The chemicals in question
are not likely to be widely used as
solvents (with the exception of
acetonitrile and, to a more limited
extent, 2-methoxyethanol, which have
significant solvent uses in some
industries), because they have
properties that limit their use to specific
situations, and are generally
noncompetitive in price. In addition,
the Agency's data collection
methodology combined a
comprehensive view not only of the
chemical's solvent use, but also of
nonsolvent uses to confirm use data.
The specificity of applications for these
solvents, while sometimes cutting
across more than one industry, is still
limited enough that the listing
determination could stay focused on the
actual management scenarios found
through questionnaires and site visits.
The Agency is confident that the waste
management practice data found in this
investigation are adequate for risk
assessment modeling, and that using
other modeling practices not found
would only lead to using hypothetical
waste data that do not represent any
activities that resemble reality. To
engage in this kind of hypothesis would
be likely to result in forcing significant
additional costs on the public with no
incremental jisk reduction from
regulating the wastes in question. The
Agency notes that no commenter
identified any specific solvent users of
these chemicals not already found by
the Agency. Also, the commenter could
not suggest any alternative to the
Agency's methodology other than a
listing based on hypothetical
uncertainties—an approach not justified
by the data.
The Agency sent almost 1,500
preliminary questionnaires asking
facilities how much of each chemical
was used as a solvent in 1991 and 1992.
The data showed that the Agency was
successful in identifying many solvent
users, although more than 900 facilities
were eliminated from further
consideration because they did not use
any of the chemicals as a solvent. The
Agency was also able to eliminate
another 400 facilities from consideration
to receive the final questionnaires due
to reporting errors, discontinued use, or
reported use of small quantities of the
solvents. The fact that the vast majority
of facilities that received the
preliminary questionnaire reported no
solvent use supports EPA's view that
many potential solvent users, in fact, do
not use these chemicals this way. The
Agency found that reported uses of very
small quantities of the chemicals as
solvents were often inaccurate, but
facilities reported these quantities to err
on the side of caution. The remaining
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64378 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
156 facilities received a large, detailed
questionnaire requesting information on
solvent uses and waste generation and
management practices. The listing
determination is based on these data.
The details of the data collection
effort also brought another point to the
Agency's attention. While other solvents
are used in countless industries and
facilities and would be difficult to
characterize, the particular set of
solvents in this listing determination
has much more limited applicability.
EPA's literature search found these
chemicals to have many and varied
"nonsolvent" uses. Data collected from
the questionnaires confirmed the
general lack of wide solvent use, as
discussed below.
While reference sources (e.g., SRI
Chemical Economics Handbook)
indicated many of these chemicals are
produced in fairly high quantities, these
references reported significant
quantities used.as solvent for only four
of the fourteen chemicals studied:
acetonitrile, 2-methoxyethanol, furfural,
and methyl chloride. This is consistent
with what EPA found in its 3007 Survey
for these four chemicals. Furthermore,
as described in the Listing Background
Document and the proposed rule, the
solvent uses of furfural and methyl
chloride were limited to a single
specialized use in each case, and these
users were fully surveyed. Solvent use
quantities were not reported in
reference sources for the other ten
chemicals. Four of the ten were those
for which EPA also found no solvent
uses (benzyl chloride, epichlorohydrin,
ethylene dibromide, and p-
dichlorobenzene). For an additional
four, EPA's Survey found that the
amounts of the production quantities
used as a solvent were small compared
to total production (cumene-0.026%;
cyclohexanol-<0.1 %; 2-ethoxyethanol
acetate-1.2%; isophorone-1.7%); this is
also consistent with the lack of
significant quantities of solvent use
reported in reference sources.
The remaining two chemicals are
special cases. The domestic production
of 2-methoxyethanol acetate is reported
to have ceased, and the small volume of
total solvent use found by EPA in its
Survey (1,673 kg/year) confirms the lack
of significant solvent use. EPA did find
Significant solvent use of the final
chemical, phenol, which was not
reported in most other reference
sources. However, nearly all (>99%) of
the solvent use quantity found in the
Survey was from one facility that
produces phenol for its own captive use.
This "native" phenol is produced as a
byproduct of other processes, and
would not be reported in production or
use data in reference sources. Leaving
out this volume from one facility, EPA's
Survey shows that the fraction of phenol
production that is used as a solvent is
low (<0.2%), which is consistent with
the lack of any significant solvent use
quantities reported in reference sources.
In any case, the vast majority of phenol
solvent use reported in the 3007 Survey
was a very specialized use; the
petroleum industry uses phenol to
extract lube oil from residual oil. EPA
surveyed all petroleum refiners in its
Survey; thus EPA is confident the
Survey captured all major solvent users
for this chemical.
The Agency disagrees that it should
project standard mismanagement
scenarios not indicated by the data,
because the rationales for selection of a
particular set of plausible management
scenarios are specific to each solvent.
Based on the general rationale just
discussed and the data for each of the
chemicals as given in detailed
discussion in the Response to
Comments Document for each of the
chemicals, the Agency has confidence
in the data set as the best available effort
to assess the chemical use universe and
actual waste generation and
management scenarios. Merely
developing hypothetical waste
generation and management scenarios,
as suggested by the comment, has no
sound basis in fact. This would lead to
the danger of over regulating risks that
do not exist and siphoning off scarce
resources to deal with those non-risks,
rather than risks that may be more
worthy of the public's attention.
For these solvents, the Agency has no
reason to project management scenarios
beyond what was found through
questionnaires and site visits. The
Agency found the vast majority of
wastes managed in tanks and
incinerators. Where a waste was
managed in a surface impoundment, the
Agency performed that modeling under
high-end exposure assumptions. The
Background Document to the proposal
and the Response to Comments
Document both present more detailed
assessments of how each individual
chemical is used, what wastes are
generated, and what management
scenarios were selected. For example,
no management scenarios were selected
for p-dichlorobenzene, epichlorohydrin,
ethylene dibromide, and benzyl
chloride because none of these
chemicals are used as solvents. For most
other chemicals, the uses are extremely
limited and specific. See the sections
devoted to the individual chemicals for
specific rationales, and the discussion of
management scenarios in section IV.B.4.
Below, EPA responds to the specific
issues raised in comments that the
Agency's survey was inadequate to
characterize the solvent uses and
mismanagement scenarios.
One commenter pointed out that EPA
surveyed only a small percentage of
facilities within very few SIC codes. The
commenter stated that for several
solvents, the quantity of sectors
potentially affected outnumbers the
quantity of facilities forming the basis
for EPA's plausible mismanagement
conclusions. As an example, the
commenter stated that for 2-
methoxyethanol acetate, EPA identified
seven industrial sectors potentially
affected by this chemical, but sent only
the questionnaire to three facilities
using the solvent.
The Agency disagrees with this
comment. As previously mentioned,
this listing determination covers 14
chemicals used as solvents. In order for
the Agency to determine the universe of
facilities potentially affected by this
listing determination, it sent out
preliminary information surveys to
obtain basic solvent use information.
The Agency sent this survey to nearly
1500 facilities based on an evaluation of
chemical usage. Given this large
universe of facilities and the potential to
obtain useful information on solvent use
in this mailing, the Agency also decided
to include in this preliminary
questionnaire questions concerning
seven other chemicals (in addition to
the 14 already included in this listing
determination) which it was also
investigating under a Solvent Study
mandated by the court.
The prequestionnaires showed that
about 600 facilities reported any
possible use of one or more of the
chemicals as solvents. The Agency
conducted further evaluations and
screening and identified 156 facilities to
which it sent the more detailed "full"
questionnaire concerning the use of the
21 chemicals as solvents (14 for this
listing determination and 7 for a
separate Solvents Study). Thus, only
about 10% of the facilities that were
sent preliminary questionnaires used
significant amounts of these chemicals
as solvents. As described in today's
document in response to other
comments, this screening removed
facilities that did not use the chemical
as a solvent (as defined by EPA), and
small volume users. For a more detailed
description of this screening and
evaluation see, please refer to section
III.A in the Response to Comment
Document for'this rulemaking.
The results of this final questionnaire
showed that 4 out of the 14 chemicals
in this listing determination were not
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Federal Register / Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations 64379
used as solvents and that 10 of the 14
chemicals were used a solvents to
varying degrees. The industry sectors
listed by SIC code by the commenter are
ones which typically do not use any of
the 14 chemicals as solvents and, thus,
did not yield data to be considered in
evaluating plausible management
scenarios. Further, as discussed earlier
in this section, all other indications
from the Agency's survey show that the
amounts of solvent use EPA found were
generally comparable to the solvent use
found in other references. The volume
of solvent use found by the Agency is
also consistent with what the Agency
knows about the likely technical
usefulness of these chemicals as
solvents. A limited set of industries
exists in which these chemicals are used
as solvents, as discovered through
standard reference sources.
The commenter presented a plethora
of small companies on the SIC code list
that operate on lower margins. The
Agency believes that these companies
are not likely to use these higher cost
chemicals for generic solvent use
processes. The Agency believes that if
any of these chemicals had been used as
solvents in other industries, as the
commenter postulates, the Agency
would have found this information
during its data collection. The facilities
surveyed by the Agency share many
processes with the large number of
smaller facilities in the lists presented
by the commenters (equipment
cleaning, electroplating, etc.). However,
the chemicals at issue are rarely, if ever,
used as solvents in those processes in
the facilities found by the Agency.
Also, the Agency recognizes that the
commenter cites a greater number of
facilities within each SIC code than the
number to which EPA has sent
questionnaires. These facility numbers
are obtained from a data base (Dun &
Bradstreet) that is not linked to
chemical use. Many of the addresses
represent corporate headquarters, not
facilities that use or generate hazardous
waste, and a single facility may have
more than one Dun & Bradstreet
number. Therefore, EPA believes that
the number of facilities reported within
each SIC code based on this data is
exaggerated.
The commenter cites 2-
methoxyethanol acetate and methyl
chloride as examples, stating that "EPA
identified seven industrial sectors
potentially using 2-MEA, but only three
facilities using the solvent received the
final questionnaire." As presented in
the background document, 14 facilities
received the full questionnaire based on
their response to the preliminary
questionnaire. However, based on their
response to the full Survey, 11 of these
14 facilities discontinued use of 2-MEA
or did not use it in a ma'hner that met
the regulatory definition of solvent use.
Only two industries reported using 2-
MEA in 1994 that met the definition of
solvent use. The commenter further
states "In the case of methyl chloride,
EPA identified eight SIC codes
potentially using the solvent, while only
seven facilities received the final
questionnaire." As presented in the
background document, 32 facilities
received the full questionnaire based on
their response to the preliminary
questionnaire. However, based on their
response to the preliminary
questionnaire, 24 facilities were TSDs,
and as a result the chemical
consumption reported could not be
linked to solvent use. Other facilities
did no't use methyl chloride in a manner
that met the definition of solvent use, or
used extremely small volumes (less than
1 kg) that generated wastes with no
methyl chloride. Thus, this left only
four facilities that reported solvent use
of methyl chloride in two industries,
and essentially all of this use was in the
synthetic rubber manufacturing.
One commenter stated that EPA chose
to review chemical abstracts for only a
four-year period, and for other solvents
limited the search to a 10-year period.
Therefore, older uses of the solvents
would not have been identified through
the literature search. The commenter
also states that newer or less studied
solvent uses would not appear in the
public literature. The commenter
disagrees with the Agency's assertion
that few, if any, solvent uses were
missed using this method.
In response, the Agency does not
believe that searching Chemical
Abstracts for an unlimited time period
for all 14 solvents is justified. If a
process was developed more than ten
years ago and is still in use today, it
would appear in more recent Chemical
Abstracts or be reflected in alternative
data sources, such as Effluent
Limitations Guidelines or the SRI
Chemical Engineering Handbook.
Furthermore, the further back the search
is conducted, the more unlikely that the
use identified will still be employed
today. Newer solvent uses, if confined
to small scale laboratory use, would not
change the solvent use universe
significantly and would be reported as
laboratory waste (and managed
accordingly, most likely as a hazardous
waste because spent solvents exhibit a
Characteristic or contain listed wastes).
Once such a process enters large-scale
commercial use, reporting generally
appears on some standard database or
literature source that the Agency would
find. The probability that a solvent use
would, in one year, not exist and then
appear in large scale is extremely low.
Small volume solvent uses of these
chemicals are not critical to EPA's
evaluation, because any risks from
larger volumes usage (and
corresponding larger loadings in wastes)
are likely to be of greater concern. Most
of the companies that would conduct
the types of research and development
to find new uses are generally reporters
to databases like the TRI, and as such,
would report any significant uses of
these solvents.
The commenter also stated that some
chemicals, such as cyclohexanol,
furfural, and isophorone, are not
reported under TRI. For the remaining
solvents, TRI reporting is not required
when chemicals are "otherwise used" in
quantities of 10,000 pounds or less
(equivalent to 4,540 kg or less). The
commenter argued that substantial
quantities of the solvents can be used
and not reported under TRI.
In response, in cases of the three
chemicals for which the TRI data base
was inadequate, the Agency relied on
other sources more heavily. In fact, the
TRI was only one source for all
chemicals in the listing determination,
even those covered by TRI. Because the
Agency was aware that these chemicals
were not required to be reported
pursuant to TRI at the time of the
solvent use industry characterization,
the Agency relied on additional sources
cited in the Listing Background
Document. Through literature searches,
potential solvent uses were identified in
several SIC codes for cyclohexanol,
furfural and isophorone.
Moreover, since the questionnaire
data were collected, the Agency added
cyclohexanol to the TRI. Analysis of TRI
chemical use data on cyclohexanol
confirms the Agency's literature search
and determination of the universe of
users of this chemical as a solvent.
While 24 facilities reported
cyclohexanol manufacturing processes
in the TRI, only one facility reported the
"otherwise use" category of
cyclohexanol that could potentially be
solvent use: Thus, the TRI data show
that the Agency might have sent out
only one additional preliminary
questionnaire (EPA received 37
responses to preliminary questionnaires
for cyclohexanol). Further investigation
by EPA revealed that cyclohexanol was
not used as a solvent at this one site.
This new information substantiates
EPA's original findings that there are no
other large users of cyclohexanol as a
solvent. See section III of the Response
to Comments Document in the docket
for details of the new TRI information.
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64380 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
The commenter argued that many of
the solvent uses EPA did identify
involve extremely high concentrations
of the chemicals, up to and including
pure solvent. These pure solvent uses
can generate wastes in quantities 100
times larger with concentrations of 1%,
still significantly in excess of
concentrations that may pose a
substantial risk to human health or the
environment.
The Agency disagrees with the
commenter that the risks of concern
were not analyzed. In fact, the Agency's
modeling considered environmental
loadings of these chemicals resulting
from solvent uses ranging from 100
percent to the part-per-million (ppm)
level. The Agency evaluated potential
releases of high percentage solvent uses
that lead to greater loadings than would
result from a one percent level in the
waste. Modeling of these chemical
releases under high end exposure
conditions did not result in risks of
concern.
In response to the commenter's
concerns that small volume users might
generate wastes of concern, perhaps due
to different management practices, the
Agency examined the data in hand from
the Survey for such users. Facilities that
received Surveys due to significant use
of some solvents (> 1,200 kg/yr), also
used other solvents in lower volumes in
some cases. Thus, the Agency has data
on wastes from facilities that used small
volumes of solvents, (see Listing
Background Document, Appendix I).
EPA reviewed the management
practices for wastes generated by these
smaller volume uses to see if any
differences were evident. For all 10
solvents, EPA found a total of 73 wastes
that were generated from solvent uses
below 1,200 kg. The Survey data show
that these were managed in ways that
were very similar to practices reported
for larger volume uses. Of these 73
wastes, 69 were incinerated or
otherwise thermally treated (nearly all
were classified as hazardous because
they exhibited a hazardous
Characteristic, or due to the presence of
other listed hazardous waste), three
wastewaters were treated in tanks, and
one wastewater was treated in a surface
impoundment (the chemical in the
impoundment, acetonitrile, was
evaluated through modeling).
Furthermore, 67 of the 73 wastes
reflected solvent use at concentrations
of 50-100%, i.e., many of these wastes
were generated from use of solvents at
high concentration. None of these
wastes from small volume users present
any special risk, because risk analyses
using larger loadings going to these
management practices found no
significant risks. Therefore, the existing
data support EPA's belief that wastes
from small volume users are not of any
special concern. Furthermore, these
wastes are nearly all handled as
hazardous, which is also consistent with
the general pattern found for other
larger volume wastes.
Two commenters stated that they
agreed with EPA's decision to limit the
solvents listing investigation to facilities
that use a combined total of 1,200
kilograms or more per year of all
chemicals of concern used as solvents
because the commenters feel that this
level represents a reasonable
characterization of the universe of
solvent users. One of these commenters
requested clarification to ensure this
approach would not be misconstrued by
hazardous waste generators when
determining their generator category. In
response, the Agency is confirming that
the cutoff categories used by the Agency
in this listing determination are not to
be construed by any actual or potential
hazardous waste generators to be a
means of determining waste generator
categories. Furthermore, EPA did
consider solvent uses below the 1,200
kg threshold as noted above, however,
the Agency found that such small
quantity use is highly unlikely to
present risks of concern when compared
to the risks from larger users.
However, another commenter stated
that EPA's rationale for deleting
facilities using 1,200 kg or less of
solvent in 1992 was that only large
quantity solvent users could be
expected to have treatment, storage, and
disposal (TSD) units on-site, and that
many of the solvent uses are peculiar to
large companies. The commenter stated
that this limitation in the data collection
introduces bias against solvent
generators relying upon commercial
services, including offsite nonhazardous
landfills, for their waste management
needs. The commenter then argued that
the Agency cannot assume offsite
disposal in a nonhazardous waste
landfill is rarely practiced when EPA
intentionally excluded those facilities
most likely to use such facilities by not
surveying smaller volume users.
The reasoning cited by the commenter
is taken out of context and does not
reflect EPA's rationale. EPA did not
decide to eliminate small volume users
because they would not have on-site
treatment capabilities. Rather, EPA
determined that the burden of
completing a complex, 100-plus page
questionnaire would not be
commensurate with the value of the
information EPA would receive. EPA
would not gain useful information from
small users because many of these
facilities, if they use these chemicals as
solvents at all, would present low risks
compared to larger solvent users.
Furthermore, as noted above, EPA did,
in fact, capture small users of solvents
in the full Survey, and found no special
management or risk concerns that were
not reflected in it evaluation of larger
solvent users.
Facilities are likely to use on-site as
well as off-site waste management
practices, and sometimes a combination
of the two. This is evidenced in
responses to the 3007 Survey, wherein
respondents indicated that both on-site
and off-site practices were employed.
The 3007 Survey has captured
numerous facilities that use commercial
services. Based on the results of the
Survey, 62 percent of the wastestreams
are managed in commercial offsite
treatment or disposal units. As such, the
Agency does not believe there is any
significant bias in its Survey.
In addition, EPA points out that the
vast majority of small solvent users
eliminated by EPA reported using
amounts well below the 1,200 kg
threshold. In fact more than 90% of
those eliminated reported used less than
120 kg total for all of the solvents
studied. EPA found that uses of such
small volumes typically were reported
for laboratory uses, are difficult to
verify, and may be reported as solvent
use if laboratory uses are not known.
The 1,200 kg/yr cutoff is an appropriate
surrogate for identifying facilities that
may potentially generate large amounts
of hazardous waste or waste with high
solvent loadings. EPA believes the
facilities with larger solvent uses would
be most likely to provide useful data
through the questionnaire, i.e., data
based on verifiable solvent use that
could then be used in developing risk
assessments.
One commenter argued that solvent
use fluctuates from year to year, thus
uses below 1,200 kg could increase
dramatically in the future due to process
changes, increases in production, or
solvent substitutions. The commenter
went on to state that use volumes for
some solvents reported in the final
questionnaire for 1993 were higher than
the rates reported for the same facilities
in the preliminary questionnaire for the
prior year. The commenter stated that
EPA fails to appreciate the consequence
of these fluctuations and substantial
changes can be expected from year to
year, e.g., a facility using less than 1,200
kg of solvent one year may use more
than that amount the next year. The
commenter concludes that EPA lacks an
objective basis for simply assuming the
data it collected is fully dispositive with
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respect to future solvent uses and
management practices.
EPA believes that the data collected
provides a reasonable bases for
decision-making. The purpose of the
preliminary questionnaire was to
capture what occurs at the facilities
surveyed during a typical year. As was
expected, some facilities' solvent use
consumption decreased between the
two years and other facilities' solvent
consumption increased between the two
years. The Agency does not expect
solvent consumptions to be identical
from year-to-year, but has no data to
indicate that 1993 is an atypical year.
Even if the specific facilities meeting the
cutoff varied from year to year, EPA
believes the data gathered from facilities
studied provide a representative
database. The Agency used the most
recent data when determining the 1,200
kg cutoff for those facilities receiving
the full questionnaire.
EPA considered whether or not
solvent management practices were
likely to change in the future from those
reported in the 3007 Survey. The
Agency determined that there was no
reason to believe that they would,
regardless of the volume fluctuation. In
the case of wastewaters, EPA has no
reason to believe that a facility would
convert from a tank-based system to a
surface impoundment given the capital
investment and liability issues
associated with land-based treatment,
particularly when facilities do not have
the physical space for a surface
impoundment or have closed surface
impoundments in favor of tank-based
systems. For nonwastewaters, EPA has
no reason to believe that a facility
would switch from the thermal
treatment of high organic wastes to
disposal in a nonhazardous landfill due
to the BTU value and the liability issues
associated with land-based disposal.
The Agency cannot accurately predict
with specificity future uses of the
fourteen chemicals, nor is it reasonable
for EPA to regulate solvent waste based
on some purely hypothetical future use.
While the solvent consumption may
change over time for some facilities,
such fluctuations are unlikely to
significantly affect EPA's current risk
conclusions for several reasons. First, in
its risk analyses EPA used high-end or
maximum solvent loadings to project
potential risks. Thus, EPA's evaluation
is not likely to change due to some
volume use fluctuations. In addition, for
most of these solvents (and specifically
for three noted by the commenter,
acetonitrile, 2-methoxyethanol acetate,
and isophorone), the vast majority of
wastes are regulated as hazardous due to
the hazardous waste characteristics (see
40 CFR 261.20-261-.24) or mixing with
other listed wastes. Thus, any increase
in volume use would result perhaps in
somewhat higher solvent quantities
reaching wastes that would be already
regulated and thus unlikely to pose
significant risk. Therefore, while EPA
agrees that its Survey is more-or-less a
"snapshot" of waste generation data, the
Agency continues to believe that such
an approach has yielded data that are
representative, and is a reasonable way
to assess potential risks.
The commenter also stated that EPA
excluded any laboratory uses of the
solvents from the universe of facilities
receiving the preliminary questionnaire,
notwithstanding the Agency's
observation that "lab use" of chemicals
was not restricted to small volumes.
The Agency did not exclude
laboratory uses of solvent from the
universe of facilities. The Agency was
precluded from sending a 3007 Survey
to all laboratories due to the sheer
number of labs that exist in the United
States, approximately 183,000 according
to an estimate by EPA. (For details
please refer to the Response to
Comments Document). Many of these
laboratories are small, comprising
research labs (12,500), medical
laboratories (22,700), and university
labs (108,000), as well as small
analytical labs (40,000). The resources
necessary to complete a RCRA 3007
questionnaire would be beyond the
means of many of these small
businesses as organizations.
Nonetheless, the Agency captured the
solvent uses and management practices
of numerous (32) captive on-site
laboratories of facilities who received
the 3007 Survey. In doing so, the
Agency captured large research, QA/QC,
and analytical laboratories that operate
at the same or larger scale as the small
labs not surveyed. Approximately 38%
of the laboratories captured were small
laboratories (i.e., using <1,200 kg of
solvent use).
The Agency found that in industrial
facilities, the proportion of laboratory
use of a solvent compared with the
chemical process use is about 1% or
less. After consulting with the American
Chemical Society, college and
university hazardous waste managers,
standard references, and OSHA
guidelines, the Agency determined that
laboratory wastes are managed as
hazardous because they are usually
mixed with other hazardous wastes,
often with acutely hazardous wastes. In
addition, with the exception of
acetonitrile (which has specialized uses
in laboratories as a solvent for high
pressure liquid chromatography, or
HPLC), the reported use of any of these
chemicals is suspect, and is attributable
to facilities reporting "solvent use" in
the questionnaires as a precautionary
measure. Few of the chemicals under
examination are likely to find extensive
use as solvents in the laboratory. For
example, very few of the standard
laboratory test methods specified by
EPA call for use of these chemicals as
solvents. For a complete summary of the
laboratory use of solvents please refer to
the Response to Comments Document.
2. Engineering Site Visit Reports
One commenter stated that the
engineering site visits were superficial
and did not encompass a thorough
review of waste management, solvent
waste characteristics, and potential
environmental releases or damage from
waste handling. The commenter
acknowledged that EPA's objective for
the site visits was simply to determine
if a facility should be sent a full
questionnaire, and to educate the
facility on the solvent listing process,
but stated that this seems like a waste
of effort, given that more valuable
information could have been obtained
from the site visits regarding waste
properties, handling and environmental
damages.
The commenter also noted that none
of the visits involved any sampling
efforts. No analytical or characterization
data are presented on the concentrations
of solvent constituents in the waste
streams observed at the industrial sites
visited. The visits were typically two
hours, with anywhere from 0-60
minutes spent actually touring the
facility. One site visit was conducted
from a tour van and was strictly a
"windshield audit," and two were
strictly conference room audits. The
reports did not investigate, evaluate, or
address any historical spills, releases to
groundwater or surface water, or any
other environmental damage from use of
the solvent or handling of the wastes.
These comments misconstrue the
reasons EPA conducted the site visits
and the information that could
practically be developed from them. The
purpose of the site visits was to
familiarize the Agency with the
multitude of processes and industries
potentially subject to the investigation
through "first person" experience rather
than "textbook" learning. The Agency
disagrees that the Engineering Site
Visits were superficial given their
purpose of site familiarity, not data
collection. The Agency points the
commenter to the engineering site visits
reports that each state EPA's objectives
in undertaking the site visit—of which
those cited by the commenter are but
two. The site visits were performed to
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obtain a first hand understanding of
solvent utilization and also to develop
a working relationship with the
industries. Moreover, the site visits
served as an outreach mechanism for
EPA to interact with industry and
inform potentially affected industries of
the investigation. Site visits afforded
EPA staff an opportunity to become
familiar with processes used in specific
industries, field test the questionnaire,
and assess ongoing pollution prevention
activities.
EPA obtained the "valuable
Information" cited by the commenter in
a more comprehensive way through the
questionnaires. EPA collected data on
waste properties and management
practices through the 3007 Survey,
which contains detailed, site-specific
information from 156 facilities. It would
not be practical for EPA to visit all sites
to gather detailed information on
solvent use. Therefore. EPA's reliance
on the 3007 Survey is eminently
reasonable for collecting information on
waste characterization data, release, and
waste management practices. Visits
conducted following the receipt of
RCRA 3007 Questionnaires helped EPA
to better understand the type of
processes used in target industries and
the data provided by respondents, and
also provided confirmation of the data
provided. The Agency was able to focus
on larger scale users and specific
processes up-close, based on the
information reported in the 3007
Survey.
As discussed in detail in the Response
to Comments Document, tours of the
facilities lasted as little as 1.5 hours and
as much as 3.5 hours, with a minimum
of 30 minutes and a maximum of more
than 2 hours spent on tour and/or on the
plant floor. Information related to spills,
releases and other environmental
damage was requested in the 3007
questionnaire and collection of this type
of information was not the focus of
these visits. The Agency takes issue
with the commenter's characterization
of the visits as "windshield audits."
None of the site visits were mere tours
from a van. The Agency personnel
witnessed many operations on a site and
were able to walk around the facility.
The commenter also mischaracterized
several other details of individual site
visit reports. The Agency has corrected
these misconceptions in the Response to
Comments document and provided
clarification to clear up any confusion,
as necessary. For more detail on the
sampling issue, please refer to section
IV.B.2 of today's document.
B. Methodology
1. Definition of "Solvent"
One commenter objected to the
Agency's characterization of solvent use
as too limiting, stating that solvents
contained in paints, coatings, dyes,
fuels, etc. are still mobilizing agents,
and that they unleash the same
environmental impact when these
products are spilled or released. The
commenter also points out that being
able to solubilize or mobilize other
constituents in a formulation still meets
the Agency's definition of solvent use.
The Agency disagrees, and notes a
long-standing policy of treating these
cases differently. The discussion of the
scope of the solvent listings and the
applicable definitions appears in section
IB, above. As noted there, process
wastes where solvents were used as
reactants or ingredients in the
formulation of commercial chemical
products are not covered by the listing.
The products themselves also are not
covered. The commercial formulations
in which solvents are often ingredients
are generally products that are not
wastes under RCRA. Where these
products are not in some way already
regulated, the Agency could examine
these materials if they become wastes
and if deemed necessary. However, with
a backlog of listing determinations to
complete under court-ordered
deadlines, the Agency has focused its
current efforts on those determinations
required by law. The Agency is under
direction from Congress to consider
listing wastes from "solvents" and that
direction has been incorporated into the
Consent Decree. Thus, the Agency has
focused its resources on the rather
narrow set of risks described in this
Federal Register document and the
rulemaking record for this decision.
2. Lack of Sampling and Analysis
Two commenters objected that EPA
performed no sampling and analysis of
these waste streams. One commenter
stated it is impossible for EPA to come
to any listing determination without
some independent sampling and
characterization of these wastes. Useful
characterization data could have been
obtained by sampling wastes from a
subset of the 156 respondents
representative of all the SIC codes using
the wastes, according to this
commenter.
EPA does not agree that it would
obtain useful information from
independent sampling of the solvent
wastes. The solvents listing
determination covers a number of
industries using different solvents for
different purposes and in different
ways. The greatest challenge would be
in collecting a sufficient number of
samples to characterize each of these
uses. Assuming that EPA were to
sample all 10 solvents, obtain both a
wastewater and a nonwastewater
sample, and gather samples from the
industries using the solvents (at an
estimate of three industries on average
per solvent), the baseline number of
samples required would be 60. In
addition to baseline samples, to conduct
a valid sampling exercise the Agency
also would need to sample for
variability, that is, the Agency would
take samples at several locations within
a single facility and would take samples
at several facilities within an industry
group using the same solvent. Assuming
that an additional two samples are taken
within the same facility, and then an
additional two facilities are visited, the
total number of required samples
reaches 540. This number still might not
allow EPA to fully characterize solvent
wastes. Thus, the Agency would be
spending scarce resources on a massive
sampling effort, when the data need
could be more efficiently obtained by
methods other than independent
sampling. While EPA could attempt a
more limited sampling approach, the
result would not be likely to provide a
sound basis for making listing decisions.
By definition, the concentration of the
solvent must be relatively high before
use, and this would allow use of mass
loadings in calculating maximum waste
levels, as needed. The Agency felt that
it could rely on the questionnaire data,
and no information has been submitted
in comments to show that sampling and
analysis was needed to confirm the
concentrations in the solvent wastes
reported. The facilities provided ranges
of concentration where concentrations
within a waste stream varied. When
data were reported as ranges, the
Agency used the high end of
concentration ranges as a conservative
approach in its risk assessment.
The Agency does not have reason to
believe that the solvent concentrations
reported are underestimated. In many
instances copies of laboratory data
showing the solvent concentration (s) in
a sampled residual were provided with
the respondents' 3007 survey. The
reported data seem reasonable and
correspond with observations of
residual streams during Engineering Site-
Visits. The solvent concentrations and
residual volumes were further
substantiated through mass balances
performed on the solvent use processes
by reviewing the 3007 survey responses
(see section III.B of the Response to
Comments Document). EPA evaluated
the data contained in the 3007 Survey
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responses for any inconsistencies or
missing residuals. If any inconsistencies
or missing residuals were found, a
follow up phone call was made to the
appropriate facility for additional
information. Where applicable, this
additional information can be found in
the docket along with the 3007 Survey
Responses. Therefore, the Agency feels
comfortable that it can rely on the
reported data to adequately characterize
risk.
EPA has used 3007 Survey data
extensively in the past in making listing
determinations. In this case, each survey
was signed by the responsible party to
indicate that the information reported is
accurate. The Agency does not have
reason to believe that the facilities
would falsify or omit any of their data
in light of the substantial penalties for
submitting false information. In
instances where concentrations were
unclear or unreported, telephone
contact was made with the facility.
Two commenters stated that EPA is
required to consider the presence of any
hazardous constituents, not just the
solvent itself, because other hazardous
constituents may be present in the waste
due to impurities, other chemicals used
in the same processes or managed in the
same equipment as the solvents, and
chemical reactions occurring in such
processes or equipment.
EPA does not agree that the Agency is
required to consider other constituents
present in the wastes examined. Indeed,
due to the extreme variability of these
other constituents in the solvent wastes
across industries, EPA would
undoubtedly find it impossible to
categorize these wastes under 40 CFR
261.11 (b) if it considered the other
constituents. The solvent uses found for
acetonitrile illustrate this problem
graphically. Acetonitrile is used as a
solvent in various industries, including
Pharmaceuticals, petrochemicals,
photographic chemicals, and other
chemical manufacturers (see the Listing
Background Document, section 4.0). The
actual uses of acetonitrile also are
variable, and include uses as a reaction
medium for the synthesis of numerous
different chemicals, and as
chromatographic eluent for analytical or
preparative separation of various
chemicals from different impurities.
Wastes resulting from such widely
varying processes across different
industries cannot be expected to have
consistent waste constituents, except for
the solvent itself.
As the commenter pointed out, other
constituents could originate from
various sources in the use of a solvent.
Thus, other constituents are dependent
on other solvents used, the specific
solvent use, other processes carried out
at a facility, other wastes that may be
generated .from other processes onsite,
etc. Because of the wide variability in
waste constituents that might arise in
wastes from use of the solvents, the
Agency focused on the solvent chemical
itself. Other constituents may vary
widely for different industries and
solvent uses; thus, the Agency believes
the only practical approach to
evaluating such wastes for potential
listing is to consider the risk posed by
the solvent chemicals under
examination.
The language in the existing F-listed
solvents illustrates EPA's special
concern with the solvents themselves in
defining the scope of the listings; the
listings are applicable only to wastes
derived from the use of the solvents at
levels of ten percent or more. In the case
of the current solvents rulemaking, the
Agency evaluated the common set of
chemicals, i.e. the 14 solvents of
concern. The Agency's assessment of
these 14 solvents shows no risk to
human health or the environment from
these wastes, as discussed in detail
elsewhere in this document.
3. Consistency of Methodology With
Other Listing Determinations
One commenter asserted that,
contrary to EPA's claim, the listing
determinations in today's rule were
based on scenarios that are different
from those EPA used in both the
proposed Dyes and Pigments listing
determination (59 FR 66072, Dec. 22,
1994) and the proposed Petroleum
Refining Process waste listing
determination (60 FR 57747, Nov. 20,
1995). The commenter stated that in the
Dyes and Pigments proposal, EPA used
plausible mismanagement scenarios of
disposal in unlined municipal landfills
and on-site monofills, in addition to
other plausible scenarios (wastewater
treatment tanks, industrial boilers). The
commenter stated that in the'Petroleum
Refining Waste determination EPA also
considered plausible mismanagement
scenarios, including disposal in on-site
and off-site Subtitle D landfills. The
commenter argued that EPA did not
follow the policy used in the Dyes and
Pigments and Petroleum Refining rules
in the proposed solvent listing because
EPA did not consider mismanagement
scenarios that reasonably could be
employed, particularly land disposal in
unlined landfills. The commenter stated
that there is nothing that prevents a
solvent waste generator from land
disposing the solvent waste, and
substantial evidence of land disposal
practices was found in the docket to the
proposed solvent rule.
In response, EPA disagrees that the
methods for determining plausible
management scenarios in this rule is
inconsistent with either the proposed
Dyes and Pigments listing or the
Petroleum listing. In both cases, EPA
used appropriate evidence to evaluate
current conditions and to project
plausible future scenarios. The Agency
does not presume unlikely worst cases
or hypothesize scenarios that are not.
likely in the interests of avoiding listing
decisions that would not result in
incremental benefits to public health or
the environment. See Dithiocarbamate
TaskForcev. EPA, 98 F.3d 1394, 1401
(D.C. Cir. 1996).
With respect to the Dyes and
Pigments proposal, management in
unlined municipal landfills and on-site
monofills was reported in the 3007
Survey for certain wastes. EPA found
that nearly all dye and pigment waste
sludges/solids studied had, in fact, been
disposed in unlined municipal landfills.
Thus, the Agency determined that
placement in an unlined landfill was
plausible for most dye and pigment
wastestreams.
However, EPA did not consider
disposal in landfills plausible for all
Dyes and Pigment wastes, and
considered the specific facts for each
waste. For example, EPA proposed not
to list one category of waste, wastewater
treatment sludges from the production
of triarlymethane pigments using
aniline as a feedstock, despite risks that
might arise if the waste were send to a
landfill. For this waste category, EPA
determined a landfill was not plausible
management (see 59 FR 66096). This
was because the current management
practice was blending with fuel for
combustion, and EPA decided that the
high organic content and fuel value of
the waste made it implausible that
landfill disposal would occur. This is
entirely consistent with EPA's approach
in today's rule for a similar waste
derived from use of acetonitrile as a
solvent. As described in the specific
section on acetonitrile (section IV.D3),
EPA does not view risks that might arise
from landfill disposal as significant
because such disposal is unlikely given
the current practice of fuel blending and
the confirmed fuel value of the material.
The commenter is also incorrect in
asserting that the approach used in
today's rule is inconsistent with that
used in the Petroleum Refining
proposal. In that proposal the Agency
evaluated landfill disposal for many of
the wastes examined, because, in fact,
this practice was reported to occur for
those wastes. Contrary to what the
commenter implied, EPA did riot project
landfill disposal in the Petroleum
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64384 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
Refining proposal as plausible for
wastes that had no evidence of such
disposal.
The commenter also stated that the
Agency violated its own risk assessment
criteria as presented in the listing
determination for the proposed Dyes
and Pigments wastes (see 59 FR 66076).
The commenter pointed out that EPA
states in the preamble that it is the
Agency policy that a high-end hazard
quotient above 1 represents a risk level
for presumptive listing, and a high-end
hazard quotient above 2 is a definite
basis to list. The commenter argued that,
if EPA applies this policy to the solvent
listing determination, at a minimum -
both acetonitrile and 2-methoxyethanol
have hazard quotients exceeding this
criteria (HQ of 200 and 16. respectively),
and should have been listed.
EPA disagrees that its decisions in
today's listing are inconsistent 'with its
listing policy. As the Agency explained
in the proposed rule, EPA's risk
assessment for acetonitrile indicated
HQs below one at the bounding level for
incineration and at the high-end for
wastewater treatment tanks and for open
storage tanks. EPA's risk assessment for
2-methoxyethanol indicated HQs below
one in bounding analyses for
wastewater treatment tanks and
incineration and no risk for the storage
tank scenario. The HQs cited by the
commenter were reported as part of an
intermediate stage of the analysis, as
reported in the background document
for the proposed rule, specifically, §5.7
of the Assessment of Risks from the
Management of Used Solvents. This
intermediate stage was used to decide if
further evaluation was necessary.
Because possible risks of concern were
found, EPA proceeded to a third phase
of assessment. After consideration of the
fact that nearly all of the wastes
evaluated in the intermediate analyses
were already hazardous, EPA's
assessments for these scenarios
indicated risks below levels of concern
for the remaining nonhazardous waste
streams (see Supplemental Risk
Assessment). These multi-phase
assessments are discussed further in
response to specific comments on
acetonitrile in section IV.D.3 of today's
document.
4. Plausible Mismanagement Scenarios
Two commenters stated that EPA
relied on incomplete data provided in
the RCRA 3007 Questionnaires to
identify actual management, and
disregarded standard potential
mismanagement scenarios based on an
incorrect assumption that solvent waste
management will not change over time.
According to these two commenters, a
valid solvent listing determination must
also consider improper disposal in
unlined landfills, impoundments, waste
piles, land treatment units, and long
term accumulation, which EPA
overlooked. One of the commenters
went on to state that the Agency's listing
policy requires the presumption of land
disposal in unlined landfills and surface
impoundments, particularly in the case
of solvents, where EPA's questionnaire
data present a partial and misleading
snapshot of solvent use due to
limitations in the data collection
methodology. This commenter also
argued that due to the limitations of the
data collection, EPA cannot claim that
the specialized or limited uses of the
solvents lead to a complete
characterization of solvent users or
solvent waste management practices.
The commenter concluded that EPA's
decision not to list these solvents is
invalid and contrary to the criteria
enumerated in 40 CFR 261.11.
The Agency disagrees with the two
commenters. The data collected show
that the management practices of most
concern to the commenters (landfills
and surface impoundments) are not
widely used. Where land-based disposal
was reported in the 3007 Survey, the
Agency considered whether the waste is
capable of posing a substantial'present
or potential hazard to human health or
the environment. For landfills, EPA
found that modeling was not necessary
because solvent loadings were very low.
The few cases of surface impoundment
use were fully evaluated via modeling
and were found to present no significant
risk.
EPA relied on management practices
reported in response to the 3007
Surveys, and EPA evaluated the
potential risks associated with those
management practices that are used or
likely to be used. As the Agency has
explained in prior responses, EPA could
and did target the facilities and
industries actually using these
chemicals as solvents. As a result, the
Agency identified the largest users of
these chemicals as solvents. EPA has
responded in detail to comments
regarding the adequacy of the
characterization of solvent waste
generators earlier in today's document
(see section IV.A.I).
The solvent wastes reported from the
Survey fell into several classes: high
concentration organic liquids or solids,
treatment residuals (wastewater
treatment sludge, incinerator ash), and
wastewaters. The high content organic
nonwastewaters were sent to thermal
treatment in incinerators, boilers, or fuel
blenders, and in some cases recovered
via distillation for reuse. The vast
majority of these wastes were managed
as hazardous waste, because they
exhibit a characteristic (primarily
ignitability), or they are generated as a
waste mixture with solvents that are
already listed as hazardous. "
From the data available, EPA
evaluated the potential for risks to arise
from disposal of solids in landfills and
the treatment of wastewaters in surface
impoundment. Wastes reported to go to
landfills were typically treatment
residuals that contained negligible
amounts of solvents. For the 10 solvents
examined (the remaining 4 on the
original list of 14 had essentially no
solvent use), no landfill disposal was
reported for six of these solvents. In fact,
of the total 435 solvent wastes reported
for the 10 chemicals, only 5 were
reported to go to nonhazardous waste
landfills. In the proposed rule and the
Listing Background Document, EPA
discussed why the few cases of landfill
disposal reported for specific solvents
(acetonitrile waste, methyl chloride,
cumene, and cyclohexanol) were not of
concern. This was principally because
the solvent loadings in these wastes
were very low. In response to
comments, EPA further considered one
waste that was reported to be disposed
in a hazardous landfill. However as
discussed in the specific section in
today's rule on acetonitrile, the waste is
no longer going to any type of landfill
due to its thermal value.
The Survey data show that wastes
sent to landfills contained negligible
amounts of solvent; landfilling of wastes
with high solvent concentration was not
reported. Thus, given these results, and
the fact that nonwastewaters with high
solvent content are generally hazardous
and could not be placed in even a
Subtitle C landfill without further
treatment, EPA had no reasonable basis
to conclude that disposal of spent
solvent wastes in landfills poses a risk
of concern.
Similarly, treatment of wastewaters in
surface impoundments was rare for the
solvent wastes examined (the vast
majority were treated in tanks). Of all
the wastes reported (435), only 10 were
reported to undergo treatment in surface
impoundments. The solvent loadings for
six of these (from solvent use of
acetonitrile and cumene) were low and
clearly present no risk after dilution/
treatment in a wastewater treatment
system. The others were larger volume
wastewaters that arose from the
specialized use of three different
solvents: methyl chloride, phenol, and
furfural. With the reported solvent
loadings available, EPA examined these
special cases closely, and completed
further modeling in response to
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Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations 64385
comments (see section IV.C. 1 on surface
impoundment modeling).
Concerning storage in waste piles and
land treatment, EPA found no cases
where such management practices were
reported for any of the wastes examined.
The lack of waste pile storage is not
surprising given the nature of most
wastes that are accumulated, i.e.,
organic liquids and aqueous
wastewaters, which are stored in tanks.
Further, many of these wastes are
already hazardous, and are therefore
kept in storage containers that meet
stringent RCRA regulations. Other solids
were either relatively low volume
wastes, for which a pile is not needed,
or wastewater treatment residuals,
which have no appreciable solvent
content, as noted above. The practice of
land treatment is a special practice that
is relatively rare, and as EPA has noted
in the past (see Dyes and Pigments rule,
59 FR 66074), such practices would be
considered plausible only when
information indicates that the practice is
in use, or likely to be used in the future.
The Agency determined that the
actual management practices represent
the plausible management practices for
the specific solvent wastes that are the
subject of today's rule, because the
Agency found no reason to believe that
the current management practices
would change significantly. In the case
of wastewaters, EPA has no reason to
believe that a facility would convert
from a tank-based system to a surface
impoundment given the capital
investment and liability issues
associated with constructing and
operating land-based treatment units.
The ongoing operating costs of
managing wastewaters in an already
installed tank are quite small relative to
the costs of constructing a surface
impoundment, or the costs of other
alternatives such as sending the
wastewaters offsite. Clearly, a large
majority of facilities perceive a benefit .
from managing the waters in tanks,
rather than impoundments, and EPA
finds no reasons to project that those
facilities would change their practices.
For nonwastewaters, EPA has no reason
to believe that a facility would switch
from the thermal treatment of high
organic wastes to disposal in a
nonhazardous landfill due to the BTU
value and the liability issues associated
with land-based disposal. In fact, the
data collected from the Survey clearly
show that the use of impoundments and
landfills is rare, and such practices are
not common for these wastes. Also, as
noted previously, the vast majority of
nonwastewaters are already classified as
hazardous waste, and cannot be land
disposed without meeting treatment
standards.
EPA believes the Survey did, in fact,
collect sufficient data from the
significant solvent users, to allow a
reasonable assessment of plausible
mismanagement scenarios. However,
even assuming the data do not reflect all
management practices for whatever
reason, the Agency still maintains that
the data available support EPA's
decisions on what constitutes plausible
mismanagement. The data collected
show that the management practices of
most concern to the commenters
(landfills and surface impoundments)
are rarely used for these solvent wastes.
Furthermore, when these practices are
used they are used for only very dilute
concentration (and low risk) solvent
wastes, except for a few special cases
that were specifically considered by the
Agency. The existing data do not
support the commenters' argument that
other practices must be assumed to be
generally plausible for all the wastes
evaluated. Creating hypothetical waste
management scenarios would have no
apparent benefit, and may lead to
regulating wastes which do not present
risks.
C. Risk Assessment
This section deals with comments on
the hazard and exposure assessments
conducted for the rulemaking. In
response to comments, the Agency
revised the risk assessment for some
management scenarios. These updated
results are presented in the following
sections, along with responses to the
comments. Full details of the updated
analyses are presented in the
background document for the risk
assessment (Assessment of Risks from
the Management of Used Solvents:
Supplemental Risk Assessment
Background Document, hereafter known
as Supplemental Risk Assessment)
provided in the docket to this rule. A
summary of risk assessment results for
all solvents are shown in Table 3.
Comments dealing with the volumes
and concentrations of wastes used as
inputs for the risk assessment are dealt
with in sections IV.A and IV.B.
1. Surface Impoundments
EPA received a variety of comments
relating to the assessment of risks from
management of solvent wastewaters in
surface impoundments. One comment
focused on the routes of exposure that
were assessed from the groundwater
pathway from surface impoundments.
The commenter indicated that EPA's
consideration of direct ingestion alone
was insufficient for assessing the risk
from this pathway, and suggested that
the Agency evaluate other routes of
exposure from groundwater. EPA agrees
that these additional routes of exposure
should be evaluated, and conducted
additional analysis as described below.
In addition, two commenters
suggested that the risk assessment
should have assumed a higher
concentration level for the solvents in
these management units. The Agency
used the headworks concentration (at
the beginning of the wastewater
treatment process), which represents a
dilution of the solvent with other
wastewaters. The high-end data on
concentrations were taken from the
section 3007 survey of all facilities, as
noted in section IV.B.2, above.
EPA does not agree that higher
concentrations of solvents should be
used, but rather believes that its
approach described below is more
appropriate. To respond to these
comments, the Agency conducted
further modeling of surface
impoundments to reevaluate the risks
from solvents managed in these units.
The risk reevaluation is summarized
below; see the Supplemental Risk
Assessment document for a full
description of the methodology and
results.
In the risk assessment for the
proposed rule, EPA reviewed the high-
end waste streams going to surface
impoundments. The process of iterative
risk screening rests on assessing high-
end values, based on the premise that
low-end values represent lower risk.
Since the high-end waste streams did
not show significant risk, EPA did not
review the impoundments further. For
the current effort, EPA ensured that all
relevant factors were accounted for by
modeling all the surface impoundments
receiving wastewaters with these
solvents. EPA used a standard Agency
model (CHEMDATS) to assess the
steady state concentration of solvent in
these units; EPA used the precursor
(CHEMDAT7) in modeling for the
proposed rule. To the extent possible,
EPA attempted to use actual influent
concentrations into the impoundments;
this information was only available for
one of the impoundments (at the Exxon
Baytown facility). For the other surface
impoundments, EPA used the
headworks concentrations again. EPA
believes that these concentrations
represent a conservative estimate of the
concentration of solvent entering the
impoundment, since they do not
account for the significant pretreatment
occurring (in all cases) after the
headworks, before entering the
impoundment. Because of this
pretreatment, the actual solvent
concentration of influent to the
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64386 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
impoundment will be much lower than
the headworks concentrations that were
assumed for the modeling.
Using CHEMDAT8, EPA then
modeled the resulting steady state
concentrations of the solvents in each
impoundment, as well as estimated
quantities and concentrations of
solvents that would be emitted to the
air, EPA assessed direct inhalation risks
using these airborne emissions from the
solvent.
Risks from the groundwater pathway
were assessed for all impoundments
where the groundwater was considered
at risk. To assess the risks from the
groundwater pathway, EPA assumed no
attenuation from the impoundment to
the leachate. EPA estimated
groundwater concentrations at a high-
end receptor, and from that groundwater
pathway assessed risks of direct
ingestion of the groundwater, as well as
inhalation and dermal contact risks
from use of the groundwater. This
assessment used the same methodology
employed by the Agency in a recent
listing (Hazardous Waste Management
System; Identification and Listing of
Hazardous Waste; Petroleum Refining
Process Wastes; 63 FR 42109, August 6,
1998 ) to estimate non-ingestion risks
from the groundwater pathway.
The results of the assessment for the
impoundments are summarized in Table
2. All hazard quotients represent
cumulative figures for all pathways and
routes of exposure. The assessment of
cumulative risk from these routes of
exposure is very conservative, in that it
assumes that receptor locations were at
the maximum exposure point for direct
inhalation of airborne solvents, as well
as for exposure to solvents in
groundwater. EPA also added HQs from
different chemicals in the same unit,
making the highly conservative
assumption that all of the
noncarcinogens threatened similar
health endpoints (i.e., cause the same
type of damage to the same organs). This
latter assumption is not likely to be true,
but there was no need to refine the risk
analysis to ascertain what the different
endpoints might actually be, because
the summed HQs were less than one.
Because those multiple conservative
assumptions were used in the analysis,
the true high-end risk estimates would
actually be lower than the numbers
listed under the "High-End" column.
TABLE 2.—RISK ASSESSMENT RESULTS FOR MANAGEMENT OF SOLVENTS IN SURFACE IMPOUNDMENTS 1
Facility
Tennessee Eastman
Exxon Baytown .
Mobil Beaumont
Lyondcll . . . . . . ..
Rhone-Poulenc . .
Citao
Solvents in unit
Acetonitrile, Phenol
Methyl Chloride2 .
Furfural, Phenol
Cumene . ...
Acetonitrile
Phenol, Furfural
Bounding HQ2
3.30&-02
[4 60e-06]
1.20e-fOO
4 ioe-02
652e-02
7.40e-01
"High-end"
HQ2
N/A3.
[3 50e-06]
8.00e-01 .
N/A
N/A
N/A.
1 Risks presented represent the total risk from concurrent exposure to air and groundwater releases, and also the sum of risks from all solvents
in the unit. The "high-end" risks are above a high-end due to these and other conservative assumptions.
2 Risks for methyl chloride represent excess lifetime individual cancer risk .
3 N/A indicates high-end analysis was not done because the bounding analysis showed no risk of concern.
2. Tank-Based Management of Wastes
In the process of responding to
comments comparing EPA's evaluation
of the solvent wastes in question with
the results of a recent EPA study on
potential air risks (see comment below
related to the Air Characteristic Study),
EPA reviewed the risk analyses
conducted in the proposed rule for
management of wastes in tanks. EPA
discovered that an arithmetic error was
made in the calculation of solvent
emissions from tanks. This error
resulted in an underestimation of
emissions for all tank scenarios by a
factor of 1,000.
EPA has therefore revised the risk
estimates for tank-based management of
wastes. The analytical approach was to
update the analyses that were
completed for the proposed rule, using
corrected emissions, the latest version of
the emissions model (CHEMDAT8), and
current chemical and toxicological
benchmark data available for some
chemicals. The analysis also refined
parameter values to more closely
approach high-end analyses;
nevertheless, because of multiple high-
end assumptions, all of the revised
analyses are still characterized as more
conservative than true high-ends. In
addition, EPA conducted a second
analysis to verify these results. This
second analysis used air dispersion data
and receptor distances from EPA's Air
Characteristic Study (May, 1998). Both
analyses, using the corrected source
term data, indicated that risks for all
tank-based scenarios were below levels
of significant concern (see section IV.C
for further discussion of listing
decisions). More details of the analyses
are presented in the Supplemental Risk
Assessment Background document. The
results of these analyses are presented
in Table 3.
BILLING CODE 6560-50-P
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Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations 64387
Table 3. Summary of Risk Assessment Results for All Solvents Examined
Solvent
Furfural
2-Methoxy-ethanol
acetate
Cumene
Cyclohexanol
2-Ethoxy-ethanol
acetate
Isophorone
Management
Scenario
Surface
impoundment
Aerated WWT
tank
On-site accumul.
Incineration
On-site accumul.
Incineration
Surface
impoundment
Aerated WWT
tank
On-site accumul.
Incineration
On-site accumul.
Incineration
Aerated WWT
tank
On-site accumul.
Incineration
On-site accumul.
Incineration
Exposure
Route
Inhalation
Groundwater
ingestion
Groundwater
non-
ingestion
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Groundwater
ingestion
Groundwater
non-
ingestion
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
HQ'2
Bounding
5.7E-01
3.3E-01
1.3E-01
-
—
1.2E-14
—
7.3E-13
3.1E-03
1.3E-06
1.4E-04
-
—
6.4E-09
—
1.3E-08
—
—
2.2E-08
—
2.3E-08
High-End
1.1E-01
3.3E-01
1.3E-01
9.0E-01
I.OE-05
—
9.0E-05
—
~
— .
—
2.4E-04
l.OE-02
~
8.0E-01
1.4E-04
2.0E-01
—
l.OE-02
—
Verification
Analysis
(Air Characteristic
Study methodology)
—
-
—
6.0E-01
5.0E-07
—
9.0E-05
..
—
—
—
1.9E-04
6.0E-03
—
9.0E-01
—
6.1E-05
5.0E-01
—
2.0E-01
— •
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64388 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
Methyl chloride2
2-Methoxyethanol
Phenol
Acetonitrile
Surface
impoundment
Aerated WWT
tank
On-site accumul.
Incineration
Aerated WWT
tank
On-site accumul.
Incineration
Surface
impoundment
Aerated WWT
tank
On-site accumul.
Incineration
Surface
impoundment
Aerated WWT
tank
On-site accumul.
Incineration
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
Groundwater
ingestion
Groundwater
non-
ingestion
Inhalation
Inhalation
Inhalation
Inhalation
Groundwater
ingestion
Groundwater
non-
ingestion
Inhalation
Inhalation
Inhalation
4.6E-062
-
—
[3.3E-14]
-
N/A3
3.6E-08
1.7E-01
1.4E-03
2.4E-02
-
--
7.4E-03
1.1E-02
1.1E-02
7.0E-02
-
- .
6.1E-07
3.5E-062
[1.3E-06]
[4.0E-06]
—
3.0E-02
—
—
-
--
—
4.6E-03
4.0E-01
—
—
—
—
1.8E+0
4.0E-01
—
3.5E-062
[4.8E-07]
[2.0E-06]
-
1.3E-02
-
-
—
—
—
1.9E-03
4.0E-02
~
—
-
—
7.3E-01
7.0E-01
-
1 The "high-end" risks are above true high-end values, because multiple high-end assumptions make the analyses
more conservative than true high-ends. z Risk numbers for Methyl Chloride represent excess lifetime individual
cancer risk 3 All wastestreams being accumulated are already regulated as hazardous wastes.
BILLING CODE 6560-50-C
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3. Multiple Solvents
A commenter noted that EPA failed to
consider the cumulative impacts of
multiple solvents and other hazardous
constituents released via the same
exposure pathways in the risk
assessment. In order to fully respond to
this comment, EPA conducted an
assessment of the cumulative risks
posed by exposure to multiple solvents.
Inasmuch as the listing determination is
based on the solvent constituents of
these wastes, other constituents of the
wastestreams were not assessed. These
risk assessment results, therefore, only
apply to the solvents themselves. In this
analysis (see the Supplemental Risk
Assessment for details) EPA assessed all
cumulative solvents risks where
multiple solvents were managed in one
unit or in different units at a facility.
This analysis used the same
assumptions as EPA's prior assessments
for the proposed rule. Wastestreams
which were already classified and
managed as hazardous were not
assessed, since there is little likelihood
of risk reduction through a listing
determination. EPA focused its effort on
currently unregulated wastes. The
characterizations of waste management
included the same conservative
parameters as in the proposed rule,
modified as described above, including
the construction and operation of
surface impoundments, meteorological
conditions, and the proximity of
hypothetical receptors. One particularly
conservative assumption was storage of
solvents in open-topped tanks
permitting maximum volatilization.
This assumption of extensive
volatilization out of open-topped tanks
is highly unlikely, because the wastes
were being stored pending incineration
or other thermal treatment. In addition
to those factors, EPA included highly
unrealistic assumptions in assessing
cumulative risk from exposure to
multiple solvents. Environmental
receptors were considered to be located
at maximum exposure points relative to
all management units. EPA also added
HQs from different chemicals, making
the highly conservative assumption that
all of the non-carcinogens threatened
similar health endpoints (i.e., cause the
same type of damage to the same
organs). This latter assumption is not
likely to be true, and overestimates
risks, but there was no need to refine the
risk analysis to ascertain what the
different endpoints might actually be.
Despite these assumptions, which
suggested unrealistic conditions to
maximize the probability of showing
risk to human health, none of the
assessed scenarios showed combined
hazard indices over one. In one facility
(Exxon, Baytown), a surface
impoundment showed an increased
cancer risk of 4E-06 in the high-end
analysis, however, this risk was entirely
due to the single solvent methyl
chloride, as shown in the preceding
section. As discussed in section IV.D,
EPA has concluded that this does not
represent a significant risk, especially in
light of existing air regulations that
apply to this unit.
The scientific evidence represented
by this risk analysis leads EPA to the
clear conclusion that management of
multiple solvents does not pose
significant incremental risk to human
health in any populations.
•4. Comparison With HWIR Exit Levels
A commenter argued that EPA should
reconsider the risks from acetonitrile,
phenol, methyl chloride, and
isophorone based on the risk analysis
presented by EPA in the proposed
Hazardous Waste Identification Rule
(HWIR; 60 FR 66344. December 21,
1995). For each of these chemicals, the
HWIR analysis produced an "exit level"
concentration, suggesting that
concentrations of waste higher than the
exit level might pose unacceptable risks.
The commenter notes that the §3007
survey showed solvent wastes for each
of these chemicals being generated at
higher concentrations than the HWIR
exit levels. The commenter noted that
wastewaters of acetonitrile, phenol,
methyl chloride, and isophorone are
generated in concentrations higher than
the HWIR exit levels for these'
chemicals.
The commenter's comparison
between HWIR exit levels and the
solvent waste concentrations does not
indicate that the solvent risks are of
concern. The purpose of the HWIR exit
levels is not to assess risk from a
particular set of chemicals or a specific
set of wastes. Unlike listings, where the
Agency makes a decision based on
actual information about how specific
wastes are generated and managed, the
HWIR levels are intended as broad risk
screens, covering a large number of
possible waste streams and waste
management methods. The listing
decisions for the chemicals examined in
today's rule are limited to consideration
of potential risks that arise 'only from
the wastes generated after the chemicals
are used as solvents. Therefore, these
decisions are limited to considerations
of waste characteristics and waste
management practices specific to these
uses.
Because HWIR had a different
purpose than this risk assessment, it
used different methodologies. HWIR
evaluated five management scenarios:
aerated treatment tanks, quiescent
surface impoundments, land application
units, ash monofills, and wastepiles.
Only two of these scenarios aerated
treatment tanks and quiescent surface
impoundments are similar to the
management scenarios modeled for the
used solvents risk assessment. Another
obstacle to comparison is the waste
volume modeled. HWIR modeled a
range of waste volumes, bounded by the
capacity of the waste management unit.
From these volumes, HWIR calculated
levels for specific chemicals on a
nationwide basis, for any use in any
industry, and made various assumptions
for waste generations and management,
as noted above. In contrast, the
wastestream volumes (and constituent
loadings) modeled for the solvents risk
assessment were based on actual data
from the industry survey.
The Agency has not issued the HWIR
in final form and is continuing to refine
the analysis; therefore, the HWIR exit
levels are currently being reviewed and
revised. However, even the revised
numbers, as a screening tool, cannot be
automatically used in assessing the
validity of other regulatory actions by
EPA. Together, the differences in
management units and wastes modeled
mean that, a simple comparison of HWIR
exit level concentrations to the
concentrations in modeled solvent
wastes is not meaningful.
5. Environmental Damage Incidents
Several commenters stated that the
Agency screened out and ignored
damage cases prior to 1980. EPA
believes that the commenters have
apparently misunderstood how the
Agency evaluated the damage cases. The
Agency did not screen out and ignore
damage cases prior to 1980. All damage
cases available were considered
including those prior to 1980, However,
most of the damage cases found for the
14 chemicals resulted from disposal
well before 1980, before RCRA
regulations were in place. Damage cases
were reviewed to direct the analysis to
industries and conditions that might
show evidence of environmental
damage from improper management of
used solvents that might be occurring
now or may occur in the future; the
cases did not provide an exclusive or
restrictive guide. EPA evaluated a
variety of legal and financial factors that
might affect plausible management, and
technological factors affecting fate and
transport of hazardous constituents.
These other factors are especially
important when examining the solvent
wastestreams, since almost 90% of the
non-wastewaters are already required to
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64390 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
be managed as hazardous under Subtitle
C. Although these constituents may
have been found at Superfund sites, it
Is not reasonable to suggest that RCRA-
regulated hazardous wastes could be
managed today in the same way they
were managed at industrial facilities in
the past. The damage cases that were
found reflect mismanagement in the
past, not the Subtitle C management (or
even the likely Subtitle D management)
of these chemicals which is the norm
today.
Furthermore, as described in the
proposed rule, there were many other
reasons why the damage cases were not
useful (see 61 FR 42326). These reasons
include: (1) EPA could not determine
that any of the contaminants of concern
were" used as a solvent prior to disposal;
(2) wastes at these sites were poorly
defined, and the term "solvent wastes"
likely referred to the more widely used
solvents that are already listed; (3) many
of the chemicals under study have other
uses that are more likely to be the
reason for contamination; and (4) EPA
found no damage cases at sites within
the industries that reported using the
solvents under study.
6. Spills, Leaks, and Overflows
One commenter stated that EPA's risk
assessment did not include an
evaluation of human health and
environmental risks posed by leaking
tank systems. According to this
commenter. EPA argues the
concentration of solvents is "very low"
in wastewaters, and thus assessing the
risks posed by tank leaks is not
warranted. However, the commenter
argued the database identifies solvent
wastewaters containing 9% 2-
methoxyethanol. 8% phenol, 200 ppm
2-EEA, 169 ppm methyl chloride, and
5,000 ppm furfural. The commenter
concluded, given that no time limit
would be placed on storage if the wastes
are not regulated as hazardous, defective
leaking containers and tanks are highly
possible.
EPA has examined the possibility of
spills from management units such as
tanks or surface impoundments. The
Agency does not have the data or the
means available to accurately assess the
likelihood of such releases, the
magnitude of releases, or other data that
would be necessary to assess the risk of
such spills. Based on the characteristics
of these solvent waste streams, however,
the Agency has concluded that to the
extent that such releases would pose
risks, a decision to list any of these
wastes would not provide significant
reduction in the potential hazards from
such events. The Agency bases that
conclusion on the following facts.
The vast majority (over 98%) of the
volume of solvent wastes are
wastewaters in wastewater treatment
units. These wastewaters are diluted to
very low concentrations of solvents, and
are treated further to even lower levels.
When necessary, EPA has modeled the
effects of release of some of these
solvents from impoundments and found
no significant risk to human health or
the environment (see section IV.C. 1 for
further discussion on potential risks
from impoundments). For the specific
wastewaters identified by the
commenter, EPA notes that surface
impoundment scenarios were modeled
for phenol, methyl chloride, and
furfural at the same or similar
concentrations to those cited, and no
significant risks were found. The
wastewater mentioned that contains 2-
methoxyethanol is managed as
hazardous in an off-site biological
treatment system, so that any releases or
risks are unlikely. Similarly, the 2-EEA
waste cited is scrubber water that is
classified as hazardous, and furthermore
corresponds to a total of only 0.58 kg of
EEA. Therefore, EPA does not agree that
these wastes are likely to present
significant risk even under a spill
scenario.
Of the nonwastewaters, almost 90%
are already regulated under Subtitle C of
RCRA. Spills from the RCRA units are
already covered under contingency
planning and corrective action
requirements. Subpart CC includes
additional requirements for spill
protection during transfer of wastes (see
40 CFR 264.1084Q)). Therefore, EPA
concludes that spills of these wastes
from tanks, which would generally be
episodic in any case and unlikely to
produce long-term exposures
comparable to those considered in
listing determinations, are not of
significant concern.
7. Non-Aqueous Phase Liquids (NAPLs)
In the proposed rule, even though
EPA could not find scenarios that could
lead to significant releases to ground
water, the Agency also considered
whether the spent solvent wastes had
the potential to form non-aqueous phase
liquids (NAPLs) that might move as a
separate phase either above or below the
ground water table. These NAPLs may
present special problems, especially in
assessing their transport and potential
impact. However, EPA found that nearly
all solvents under consideration are
miscible or very soluble in water and
are not likely to form NAPLs in
groundwater. One commenter suggested
that EPA re-examine the possibility of
formation of NAPLs from these solvents.
To respond to this concern, EPA has
conducted further analysis on the
subject for this final rulemaking. Full
details of this analysis are in the
Supplemental Risk Assessment
document for this rulemaking. Only four
of the solvents are land disposed and
pose a threat to the groundwater
pathway: acetonitrile, phenol, furfural,
and cumene. EPA assessed the
possibility of formation of NAPLs from
land disposal of these solvents.
The first three are all highly soluble,
which indicates that NAPL formation is
unlikely. EPA then assessed the
likelihood of NAPL formation from
cumene, using the methodology which
has been developed for assessing NAPL
probabilities at Superfund sites.
Conservative estimations of the
concentrations of cumene in
groundwater still fell an order of
magnitude below the threshold at which
NAPL formation is a serious possibility.
Therefore, EPA concludes that there is
little likelihood of these solvents
contributing to formation of NAPLs.
8. Risk Modeling Parameters
One commenter stated that the
accumulation scenario modeled must
assume long term storage, not a period
of under 90 days. The commenter
argued that extended on-site
accumulation is a highly plausible
mismanagement scenario, given that
absent RCRA controls, a generator can
accumulate such waste indefinitely.
Thus, the commenter stated that EPA's
risk model should not assume a finite
storage time of 90 days, but should
assume the more likely scenario of at
least a two year period of storage.
This comment is based on an
incorrect assumption. The accumulation
scenario was not modeled for a period
of 90 days as stated by the commenter.
For each scenario, EPA used a storage
duration designed to maximize the total
risk. Modeling a longer storage time
does not necessarily increase the risk,
because it implies less frequent refilling
of the tanks with new wastes. As
described in the risk assessment
documentation, this storage duration
time was calculated by first generating
a tank profile to yield the largest
downwind concentration at the nearest
residence based on data in Hazardous
Waste Treatment, Storage, and Disposal
Facilities (TSDF)— Background
Information for Proposed RCRA Air
Emission Standards (referenced in the
proposal risk documentation as U.S.
EPA, 1991c; p. 29, July 1996). (This
high-end tank also happened to be the
most common. Therefore, this model
tank was used for all three types of
estimates: bounding, high-end, and
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central tendency.) The throughput and
• other parameters of this model tank
were used in combination with solvent
throughputs and high-end and central
tendency concentrations to obtain
solvent-specific emissions rates. The
storage duration times were then back-
calculated to fit this maximum release
profile. For the bounding analysis, the
modeling was so conservative that it
resulted in greater than 95 percent
release of the solvent in seven out of ten
cases. Thus, a longer accumulation time,
as suggested by the commenter, would
have led to lower emissions, lower
concentrations at the receptor, and thus
a less conservative analysis.
9. Comparison With Results of Air
Characteristic Study
EPA received a late comment
suggesting that the risk analysis in the
Air Characteristic Study recently
released by the Agency (May, 1998)
indicated that air pathway releases from
these solvents were riskier than EPA's
initial analysis had indicated. The
commenter compared concentration
levels of potential concern developed
for some chemicals in the Air
Characteristic Study to concentrations
of the solvents reported in the listing
determination. The commenter argued
that the study showed significant
inhalation risks for some of the solvents
when managed in tanks at
concentrations significantly lower than
those found in the solvents data
collection.
In response, EPA first notes that the
purpose of the Air Characteristic Study
was to evaluate the possible need for an
air characteristic to address potential
risks due to emissions from certain
waste management units. The
concentrations of concern estimated in
the Study are screening values for the
purpose of determining whether new
regulatory controls are needed to fill
potential gaps in existing regulations,
and should be viewed in this context.
The concentrations developed in the
Study cannot be automatically used in
assessing the validity of other regulatory
actions by EPA, because the study uses
waste data and certain modeling
assumptions in its methodology that are
different in a number of ways from the
modeling assumptions and data used in
other regulatory programs, such as
listing determinations. In addition, the
Study methodology is currently
undergoing outside peer review.
Therefore, the screening concentrations
themselves could change pending the
results of the review.
In any event, a comparison of the
results reached in the Air Characteristic
Study with the results of this risk
assessment confirms that the
concentrations present in these solvent
wastes do not pose a significant
inhalation risk. As noted above, EPA
found an error in the risk analyses for
tanks, and revised these analyses
accordingly. This was the principal
reason for the apparent difference in
risk estimates between the risk
assessment for the proposed analysis
and the Air Characteristic Study (see
section IV.C.2). However, even with
these revisions, some apparent
differences in concentration levels of
concern would remain.
These differences in concentration,
however, do not necessarily mean
differences in risk. In this case, the
source terms being compared are
different. The Air Characteristic Study
back-calculated to determine what
loading of constituent could be safely
managed in a given management
scenario. For every management
scenario, the loadings of constituent that
the Air Characteristic Study concluded
could be managed safely are larger than
the loadings used in this risk
assessment. The solvent constituent
loading that the Air Characteristic Study
determined could be safely managed in
tanks ranged from twice the amount to
millions of times the amount modeled
for the solvents risk assessment. The
analyses for today's listing
determination used the solvent waste
generation data (and subsequent
loadings in management units) from the
§3007 Survey. The purpose of this
listing is to determine the risks that may
be posed by current and plausible future
management of these specific chemicals
when used as solvents, therefore, the
EPA feels that the solvents waste
generation data submitted from the 3007
survey is appropriate to use in the
analysis.
, To better understand the differences
in risk assessment methodology used in
the Air Characteristic Study, the Agency
conducted a re-analysis of the risk from
the solvent wastestreams using a
modified methodology from the Air
Characteristic Study, but still using the
waste generation data and solvent
loadings from the listing Survey. The
methodology was virtually the same as
that used in the Air Characteristic
Study, except for some inputs that the
study derived through Monte Carlo
analysis. The results of this verification
analysis showed no significant risk for
any of the solvent management
scenarios, and confirm the previous
results. These results appear in Table 3.
More details on these comparisons
appears in the response to comments
document accompanying this
rulemaking.
D. Listing Determinations
EPA received comments on various
aspects of the proposed listing
determinations. Many comments on the
determinations were raised repeatedly
for various wastes, and are discussed in
preceding sections, or in sections IV.D. 1
and IV.D. 2 below. Comments that are
more specific for individual solvent
wastes are addressed in the section
IV.D.3. For complete responses to
comments on these and other issues, see
the Response to Comments Document in
the docket to today's rule.
1. General Comments
Six commenters support EPA's
decision not to list as hazardous waste
the solvents at issue. However, one
commenter disagreed with the decision
not to list these compounds because
they are similar in toxicity to the other
solvents already listed as hazardous.
The commenter stated that the solvents
considered in this rule may be used by
themselves, and their wastes, therefore,
would not be mixed with the wastes
from the other F-listed wastes, or the
manufacturer can modify their
processes to avoid using other F-listed
solvents, so that their wastes would no
longer be hazardous. The commenter
went on to wonder if EPA's decision not
to list these wastes was due to its "anti-
combustion" strategy, because the
wastes would "then be readily excluded
from combustion as a logical disposal
option."
EPA does not agree with the
commenter's assertions regarding the
decisions not to list. While some of the
chemicals examined in today's rule may
have toxicity similar to the solvents
already listed as F-wastes, the toxicity of
a chemical alone is not a sufficient basis
for listing. EPA considers a variety of
factors, including waste management
practices and all the other factors listed
in 40 CFR 261.11 (a) (3). After evaluation
of all factors, EPA determined that
listing for these solvent wastes was not
warranted. When appropriate, EPA also
evaluated wastes that resulted from use
of the solvent by itself and found no
significant risks.
Further, EPA disagrees that in the
absence of a listing decision a
manufacturer would change its
processes to segregate out the solvents
considered in this rule. They had that
incentive from the time the other
solvents were listed in 1980 and 1986
and have either been mixing the wastes
ever since or made decisions to make
new mixtures with listed solvents. If a
waste is hazardous under current
regulations, due to mixture with other
listed wastes or a characteristic, the
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manufacturer already has ample
incentive to modify its process to avoid
the cost of generating more hazardous
waste. These manufacturers apparendy
weighed the risks and benefits of
mixing, or not mixing the wastes and
Still pursued their mixing practices. As
the Agency has stated in today's
document and in the Response to
Comments Document, many of these
decisions are driven by specific process
parameters, cost effectiveness, chemical
compatibility, and regulations of other
Agencies, EPA has no reason to believe
they will change these practices in the
event of a final no-listing decision,
considering that this decision does not
change the status quo. Thus, EPA does
not agree that a non-list decision would
alter this behavior. Finally. EPA points
out that many of the wastes examined
in today's rule are, in fact, treated by
combustion, typically in hazardous
waste incinerators. Therefore, the
wastes are not "readily excluded" from
combustion as result of the no-list
decisions.
2. Sufficient Regulation of Solvents
One commenter stated that EPA
assigned appropriate weight to the fact
that many solvents already are
hazardous, a determination that is
relevant to the Agency's assessment of
plausible mismanagement scenarios, its
determination in the risk assessment
that no further risk reduction could be
achieved through listing the solvents of
concern as hazardous, and its
determinations regarding the relevance
and applicability of damage incidents
identified. This commenter further
stated that EPA gave due consideration
to the benefits accorded by other
regulatory programs. Another
commenter, however, stated that the
Agency should carefully consider the
benefits associated with listing the
solvent wastes that may exhibit a
hazardous waste characteristic or are
sometimes co-managed with presently
listed solvent wastes. This commenter
stated that there are important legal and
policy reasons for listing the solvent
wastes at issue in this rulemaking. The
commenter noted that in the case of
characteristic solvent wastes, listing the
respective wastes obviates the need for
testing to determine whether the waste
is hazardous and could facilitate
enforcement because inspectors need
only compare the waste to the listing
description to verify the applicability of
hazardous waste requirements.
In response, the Agency notes that it
did carefully consider the impact listing
might have for solvent wastes that are
already hazardous due to the
characteristics, or mixture with
hazardous waste. For the wastes under
consideration in this rulemaking, EPA
believes that the characteristics provide
adequate regulatory control. EPA
initially evaluated potential risks from
all wastes and found risks of possible
concern due to air releases from some
wastes (for acetonitrile and 2-
methoxyethanol; see proposed rule 61
FR 42327-42332). However, the wastes
with the apparent risks were already
regulated as hazardous. After
considering the regulatory controls
required, the residual risks were found
to be below levels of concern. Based on
assessments of risks posed by these
wastes, in conjunction with the existing
regulatory controls afforded by the
existing characteristics and listings, the
Agency determined that the solvent
wastes as they are generated and
managed do not pose a threat to human
health or the environment. Therefore,
the Agency has decided that listing is
not warranted. While listing would
obviate the need for testing (for those
wastes not already listed or mixed with
a listed waste), this is not a compelling
reason by itself to list. A listing may
assist enforcement to some extent;
however, EPA has no indication that
there is any problem in the
implementation of the characteristic
regulations for these wastes. On the
contrary, the data collected indicate that
generators are, in fact, managing the
wastes of concern as hazardous when
they are subject to such regulations.
The commenter states that EPA never
addresses the actual or potential
reclamation of characteristic solvent
sludges and byproducts (See 40 CFR
261.2, Table 1). The commenter also
argued that the regulatory status of
residuals from the recovery of spent
solvent wastes are different for listed
wastes; if listed, the residuals are
hazardous, but if not listed the residuals
would be unregulated, unless they
exhibit a hazardous characteristic.
The Agency disagrees with the
statement that EPA did not consider
reclamation. The Agency examined all
residuals generated, including those
generated from on-site recycling
operations. Through the Survey, the
Agency collected data on actual or
potential solvent recycling and
reclamation possibilities. Among the
residuals evaluated are heavy ends,
filtrates/decantates/distillates, organic/
aqueous treated residuals, and filter
related media; these were, in part,
generated from the recovery of spent
solvents or the treatment on-site of
spent solvent residuals. Some facilities
have the means and the financial
incentive to perform reclamation of
used solvents (often in-process). Other
facilities are prevented from performing
any sort of reclamation due to process
purity requirements and product quality
needs (e.g., pharmaceutical drugs,
semiconductors), which may include
regulatory requirements (e.g., purity
requirements for drugs under the Food,
Drug and Cosmetic Act). Aside from
value to fuel blenders and incinerators,
very little market seems to exist for
many spent solvents or their sludges.
While it is true that the regulatory status
of recovery residuals is different for
listed, as opposed to characteristic
hazardous waste, EPA does not believe
that this would, by itself, provide a
strong reason for listing, unless risks can
be demonstrated for such wastes. EPA
has no data on the characteristics of
such off-site residuals, and in fact has
no indication that many of the spent
solvents at issue are sent for off-site
reclamation, beyond thermal treatment.
Furthermore, in making a listing
determination, EPA's primary focus is
the wastes generated on-site, and not
treatment residuals that may be
generated off-site. To fully consider
these derivative wastes would expand
the scope of a listing into a much larger
effort. EPA has chosen to examine
wastes for which it can reasonably
expect to collect sufficient data to
support a listing evaluation.
The commenter goes on to state that
in the HWIR rulemaking, EPA has not
set exit levels for most of the solvents
covered by the instant rulemaking.
Therefore, wastes may meet the HWIR
exit levels but still contain substantial
concentrations of non-listed solvents.
The commenter stated that by listing as
hazardous the solvents in this
rulemaking, EPA would then develop
exit levels for the solvents, thus
ensuring the concentrations of these
solvents in waste mixtures are reduced
to protective levels prior to leaving the
Subtitle C regulatory system.
The commenter is premature in
assuming the content or effect of the
HWIR rulemaking, and an assessment of
the effect of that potential rule on
residuals addressed in today's final rule
is speculative. The Agency points out,
however, that the concentrated waste
mixtures reported for the solvents at
issue are unlikely to be realistic
candidates for exemption under HWIR.
Due to the high levels of other
constituents, these wastes most
certainly have to be treated, such that
the wastes that might ultimately exit the
RCRA system would be treatment
residuals. Concentrated organic wastes
are invariably treated through
incineration or other thermal treatment,
and such treatment would likely destroy
the solvents in question, as well as the
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other hazardous constituents.
Furthermore, wastes that are
characteristic must be treated for
underlying constituents under the Land
disposal restrictions (LDR) regulations.
Thus, residuals that are exempted under
HWIR are not likely to have solvent
levels of any concern.
The commenter also stated that by
listing the wastes as hazardous, EPA can
encourage pollution prevention
activities associated with solvent uses
and waste management, including but
not limited to solvent substitution,
process changes and less reliance on
combustion. The commenter noted that,
through the listing process, EPA could
ensure that the wastes will always be
.managed as hazardous, recognizing that
attempts to identify solvent uses and
users in the proposal are at best,
substantially incomplete and subject to
change. The commenter stated that it is
entirely plausible that pollution
prevention programs emphasizing
hazardous waste generation reductions,
the increasing cost of disposal
associated with the upcoming
hazardous waste combustion rules, and
other factors will encourage hazardous
solvent waste generators to reduce or
eliminate the use of listed hazardous
waste solvents. Under these
circumstances, current codisposal
practices are not indicative of future
mismanagement scenarios.
The Agency believes that the existing
regulatory requirements for these
wastes, many of which are hazardous
already, provide ample incentives for
pollution prevention, both because of
liability concerns and disposal costs
associated with hazardous wastes. In
addition, as noted above, under the LDR
regulations, characteristically hazardous
wastes must be treated for underlying
hazardous constituents. The Agency has
reason to believe that industry
voluntarily'assesses opportunities for
pollution prevention. As stated in the
Listing Background Document (page 17),
all but four of these chemicals are
reportable in TRI Form R. Part of that
reporting package includes pollution
prevention and waste minimization. As
an example, use of the three glycol ether
chemicals under consideration in this
rulemaking (2-methoxyethanol, 2-
methoxyethanol acetate, and 2-
ethoxyethanol acetate) has diminished
significantly, and production of 2-
methoxyethanol acetate has been
eliminated. Further, the cost of these
chemicals is high in comparison with
other comparable chemicals. These
chemicals are used in industry only
when their application is considered so
suitable as to overcome any price
disadvantages. As a result, for the
solvents under consideration in this
rulemaking, both regulatory
requirements (e.g., characteristics, TRI)
and economic factors play a role in
encouraging companies to undertake
pollution prevention assessments and
institute changes where possible. Thus,
EPA finds no reasonable basis to project
changes in management practices
reported in the 3007 Survey, as
suggested by the commenter.
The Agency has no reason to suspect
that current management practices
would be likely to change in the future
to a practice that would pose a
substantial risk to human health or the
environment (e.g., from thermal
treatment to land disposal or from a
tank-based system to a surface
impoundment) due to the regulatory
prohibitions, heating value of the waste
and/or requirements of the facility's
wastewater treatment systems.
The commenter also stated that EPA's
assumption that analogous waste
streams generated by all industry sectors
using any of the solvents always
generate an ignitable hazardous waste
(based on the fact that some of the
wastes reported to the Agency in the
questionnaires are ignitable hazardous
wastes), and will continue to do so, is
not sustainable given the limitations
associated with the preliminary and
final questionnaires.
EPA disagrees. Nowhere does the.
Agency assume that analogous
wastestreams generated by all industry
sectors using a particular solvent always
generate an ignitable waste. The Agency
has determined, based on reported
management practices, that additional
management practices for high solvent
concentration/high organic containing
wastes other than those considered in
the risk assessment are not likely to
exist. While some solvents may exist in
mixtures at levels that do not exhibit the
ignitability characteristic, EPA assessed
risks from such mixtures as reported in
the 3007 Survey. In fact, the initial risk
analyses for all solvents did assess the
risks from the wastes reported to be
hazardous. Except for the cases of
acetonitrile and 2-methoxyethanol, EPA
did not pursue the impact of the
hazardous waste designations, because
the risk results for the other solvents
were below levels of concern. In the
next phase of risk analyses for
acetonitrile and 2-methoxyethanol, the
Agency did not find significant risks
from any remaining nonhazardous
wastes. (See Supplemental Risk
Assessment document for more details.)
The Agency found that process and
other limitations are a technical and
regulatory bar to using the 14 chemicals
alone or in combination with non-listed
solvent wastes. For example, FDA
regulations preclude solvent
substitution in the pharmaceutical
industry. Similarly, chemical purity
concerns and final product quality
requirements often specify the
chemicals to be used.
Another commenter stated that EPA
had wrongly assumed that the 10
solvent wastes are already captured as
hazardous by the characteristics. The
commenter states that four of the ten
solvents of concern have flash points
that do not meet the characteristic of
ignitability: phenol, isophorone, furfural
and cyclohexanol. Wastes from these
four chemicals could never exhibit the
characteristic of ignitability, unless
generated in mixtures with some other
component that has a low enough flash
point. Two commenters provided
calculations, using Raoult's Law and the
lower flammability limit, of the
potential concentration of solvents in a
mixture that would result in an ignitable
waste. These commenters contend that
the solvent concentration in the
mixtures must be very high to produce
a mixture that is ignitable.
As noted above, EPA did not need to
rely on the fact that all waste mixtures
would be ignitable. Certainly for the
four solvents mentioned by the
commenter, EPA did not rely only on
the hazardous waste designations, but
rather presented risk results for all
wastes reported. In addition, the amount
of solvent in nonwastewaters for two of
the chemicals cited were extremely
small (cyclohexanol-16 kg; furfural-
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proposed rule and as modified by
subsequent analysis in response to
comments, EPA finds no significant
risks from treatment in aerated tanks or
combustion in a boiler. EPA concludes
that potential risks from air releases of
acetonitrile stored in open accumulation
tanks (i.e., on-site storage tanks) are also
not significant, because the vast
majority of the nonwastewater residuals
stored are already regulated as
hazardous waste. In the latter case
regulatory controls afforded by the
existing solvent listings and the
characteristics (primarily ignitability)
are protective of human health and the
environment.
EPA's final determination not to list
this solvent is also based on the analysis
in the proposed rule (see 61 FR 42328),
as modified by subsequent analysis in
response to comment, that potential
risks from land-based management of
acetonitrile wastes are not significant.
All wastewaters found in EPA's 3007
Survey were treated in tanks, except for
several wastes that were reported to
enter impoundments as part of a
wastewater treatment train in volumes
that would not present significant risk.
In response to comments, EPA
conducted further analysis of the
potential risks that might arise from
treatment of acetonitrile wastewaters in
a surface impoundment. This analysis
included consideration of any
additional risk resulting from
noningestion exposure from
groundwater (e.g., inhalation). As
described in section IV.C, these analyses
further confirmed this management
practice presents no significant risks
(see Table 3).
The proposal also found that the few
wastes reported to go to landfills
typically contained negligible levels of
acetonitrile solvents, and were not of
concern. In response to comments, EPA
further examined the potential for risks
that might arise if more concentrated
wastes were placed in an unlined
Subtitle D landfill, but continues to
believe such risks are not of concern
(see specific comments below).
As described in section IV.B, EPA
updated its risk analysis for acetonitrile
for some management scenarios. While
the updated analyses confirmed the
evaluation in the proposed rule, the
updated analysis for aerated wastewater
treatment tanks showed an HQ of two,
which is slightly above the Agency's
presumptive no-list HQ level of one.
EPA does not believe this marginal risk
is significant for the following reasons.
First and foremost, as noted earlier in
section IV.B. the analysis that resulted
in the HQ of two is actually more
conservative than a true double-high
end analysis. The dispersion modeling
used in calculating the HQ of two
incorporates a high-end receptor
distance, in addition to two other high-
end parameters used (solvent loading
and tank scenario). Furthermore, the
solvent loading used for this analysis
was the maximum reported for
acetonitrile in wastewaters, rather than
the 90th percentile value that EPA
typically uses to estimate high-end risks
(see for example the risk analyses in the
recent Petroleum Listing, 63 FR at
42117). In the 3007 Survey for solvent
use, facilities reported the treatment of
26 acetonitrile wastewaters in tanks (see
the Listing Background Document, App.
I), and the maximum was above the
90th% value for the mass loadings from
this distribution. EPA used the second
highest loading, which was an order of
magnitude below the maximum, to see
the impact of using this value in the
updated analysis. When using the 2nd
highest loading, EPA calculated an HQ
of 0.02, or well below one. Thus, the HQ
of two is an overestimate and does not
reflect a significant risk. As further
confirmation, EPA also estimated risks
for acetonitrile wastes using the
methodology from the Air Characteristic
Study. This methodology allowed
receptor distance to be varied and was
thus closer to a true high-end analysis.
Using either the maximum acetonitrile
loading or the second highest loading,
the estimated HQ's were below 1.0 (0.7
and 0.08 respectively). Finally, EPA has
recently promulgated regulations under
the Clean Air Act (CAA) to control air
releases from the industry represented
by the one facility with the maximum
loading (September 11, 1998, 63 FR
50280). These standards control releases
of hazardous air pollutants, such as
acetonitrile, from wastewater treatment
systems at pharmaceutical producers.
Therefore, for these reasons the Agency
does not believe that the risks from
acetonitrile in wastewater treatment
tanks are likely to be significant.
Given that nearly all of the
nonwastewater acetonitrile residuals are
either already being handled as
hazardous, and those that are not
handled that way contain negligible
amounts of the solvent, these spent
solvent residuals are not likely to pose
a significant hazard to human health or
the environment. Furthermore,
treatment of wastewaters in tanks, or in
rare cases in impoundments, presents
no significant risks. Therefore, the
Agency continues to believe that a no-
list decision is warranted.
Specific comments. Several
commenters support EPA's no list
decision on Acetonitrile. The
commenters confirmed that the
management practices and
characterization of wastewater and
nonwastewater residuals from the use of
acetonitrile as a solvent have been
properly identified. One commenter
also noted that the risk assessment
conducted by the Agency supports the
determination not to list acetonitrile
spent solvents. However, another
commenter disagreed with the Agency's
findings, stating that, despite
shortcomings in EPA's risk assessment,
the high-end analysis for tank storage
resulted in an estimated HQ of 200,
orders of magnitude higher than the HQ
of 1 typically warranting a hazardous
waste listing. This commenter noted
that only by performing the Phase III
assessment was the Agency able to
rationalize a no-list decision.
In response, EPA wishes to clarify the
meaning of the different phases of the
risk assessment. The iterative process of
risk assessment began with bounding
analyses as the first phase. This type of
analysis (by definition) involves
conditions so unlikely as to be virtually
impossible. Many scenarios did not
show significant risk. Those scenarios
which showed significant risk under
bounding conditions were assessed
under "high-end" conditions in Phase
II. This was a more realistic assessment,
but still reflected close to a "worst-case"
set of conditions.
Of all scenarios evaluated for
acetonitrile, only one showed
significant risk when modeled under
high-end conditions, an uncovered
storage tank (also called on-site
accumulation in the proposal). The
commenter refers to the hazard quotient
of 200 calculated for this scenario.
However, this result was reported as an
intermediate step in the risk assessment
process. EPA had significant concerns
about this result for two basic reasons.
First, this scenario involved storage of
solvent wastes pending incineration.
Modeling limitations required the
Agency to estimate risks based on
solvent storage in tanks without covers
of any kind. In fact, the scenario
assumed that essentially all of the stored
acetonitrile would volatilize from the
tanks before incineration could take
place. The Agency judged this scenario
highly unlikely because the waste is
being stored for thermal treatment, and
it is irrational to assume valuable fuels
would be allowed to escape in such a
manner. Further, as explained in the
proposed rule, the vast majority of the
wastes are already classified as
hazardous waste because they are either
characteristically hazardous, or co-
managed with listed hazardous wastes.
As such, the storage units would have
to comply with RCRA regulations
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promulgated to control such air releases
(see 40 CFR part 264, subpart CC). Thus,
the HQ of 200 is clearly an overestimate,
because it was based on modeling
releases for wastes that are already
hazardous.
In order to assess potential risks from
the nonhazardous wastes that were not
already subject to Subtitle C controls,
the Agency refocused the assessment on
the nonregulated waste streams in this
scenario (acetohitrile in storage tanks).
This third phase of the risk assessment,
is a normal and logical step in the
iterative risk assessment process. Phase
III of the assessment showed that a
bounding analysis of these wastes
resulted in an HQ below one. Therefore,
EPA concluded that the risks from the
nonhazardous portion of the acetonitrile
wastes are not significant, and that
listing of solvent wastes from the use of
acetonitrile is not warranted.
One commenter states that large
quantities of acetonitrile wastes are
generated in concentrations well in
excess of levels capable of posing a
substantial risk to human health or the
environment, and are managed in ways
inconsistent with the Congressional
directive to minimize the toxicity of
mobility of wastes destined for land
disposal. The commenter stated that
large quantities of solids containing
10,000 ppm solvent are disposed in
hazardous waste landfills, while the
Universal Treatment Standard (UTS)
applicable to acetonitrile is 1.8 ppm.
EPA disagrees that large quantities are
generated that present substantial risks.
The Agency evaluated risks based on
potential exposures arising from
plausible management. The highest
concentration of acetonitrile going into
a surface impoundment is no higher
than 0.04 mg/L (see Listing Background
Document, Table 3-2). In fact, it would
likely be much lower, since those
wastewaters are pretreated before
entering the impoundment. As
described in section IV.C.1, further
modeling done for surface
impoundments confirmed that risks
from such levels were not significant.
The commenter is incorrect in stating
that large quantities of solids containing
10,000 ppm acetonitrile are disposed in
hazardous waste landfills.,First, as
noted previously, very few acetonitrile
wastes were sent to landfills, i.e., four
out of the 254 wastes reported in the
Survey. The commenter singled out the
one waste with appreciable acetonitrile
loading (454 kg/yr.). In EPA's view, this
one waste is not reflective of "large
quantities" going to landfills.
Furthermore, as described further in the
following response, the practice is no
longer occurring, and the facility in
question is currently sending this waste
stream for fuel blending, in recognition
of its fuel value. ,»
The Agency disagrees with the
commenter's conclusion that current
management practices are inconsistent
with the Congressional directive to
minimize the toxicity and mobility of
wastes destined for land disposal. The
vast majority of the acetonitrile waste
(nonwastewater), both by volume (99%)
and by acetonitrile loading (99%), is not
managed in land-based units.
Furthermore, as noted above, the vast
majority of acetonitrile wastes are
already hazardous, and as such, must
meet the Land Disposal Treatment
standards prior to land disposal.
Finally, as described earlier in today's
document, some commenters argued
that EPA should examine more land
disposal scenarios, such as landfills. In
response, the Agency examined
groundwater ingestion risks from the
disposal of acetonitrile solids in an
unlined landfill. The Agency still
believes that landfill disposal of
acetonitrile is not a plausible
management scenario, and there is no
evidence that such waste has ever been
disposed in Subtitle D landfills. To the
contrary, the only facility that had been
sending a significant acetonitrile
loading to a landfill (454 kg/yr) sent the
waste to a Subtitle C landfill.
Furthermore the facility indicated that it
had ceased this practice during 1993
and started sending the waste for
thermal treatment because of the waste's
fuel value. (EPA has received
confirmation from the generator of this
waste that the material has fuel value on
the order of 14,800 BTU per pound.1)
Thus, EPA believes that such wastes
will be sent for thermal treatment under
the current regulatory structure. The
Agency decided, however, to examine
the resulting risks if such disposal were
to occur in an unlined Subtitle D
landfill. As described in more detail in
the Supplemental Risk Assessment, the
resulting analysis suggested hazard
quotients in the range of 11-22 for a
high-end scenario.
EPA does not view these risks as
significant, however, for several reasons.
First, as noted above, landfill disposal is
unlikely given the fuel value of the
material, thus EPA does not view
disposal in a D landfill plausible. In any
event, the elevated HQs were projected
for only one waste out of the 254
acetonitrile wastes identified in the
3007 Survey. Even if EPA found that the
1 See contact report dated June 10. 1998
documenting a telephone conversation with Dave
Giffen. B.F. Goodrich, which is located in the
docket accompanying today's rule.
elevated HQs reflected a plausible
management scenario, the Agency might
well decide that the potential risk posed
by this one waste does not merit listing
of all acetonitrile residuals generated.
Given the widely varying nature of the
industries and wastes involved, and the
very small percentage of management
activities that even arguably could
present a risk of concern, the Agency
believes that a broad listing for solvent
use would result in over regulation. In
any case, EPA concludes that wastes
such as these are not likely to be
disposed in landfills, and are therefore
unlikely to pose significant risks.
Phenol. Decision. EPA is not listing
wastes from the solvent use of phenol as
hazardous waste under 40 CFR 261.31.
As described in the proposed rule and
as modified by subsequent analysis in
response to comments, EPA finds no
significant risks from treatment in
aerated tanks, storage in tanks, or
combustion in a boiler. Furthermore,
EPA does not believe that potential risks
from land-based management of phenol
wastes are significant. None of the
wastes containing phenol were reported
to go to landfills. Wastes with high
organic content that contain any
appreciable levels of phenol were
classified as hazardous waste, and were
sent for fuel blending or incineration as
hazardous. Wastewaters were generated
from the specialized use of phenol as a
solvent in the extraction of materials
from crude oil, and the resulting spent
phenol wastes were sent to wastewater
treatment systems for treatment in tanks
or surface impoundments. EPA found
risks from impoundments would be low
given the dilution and treatment that
occurs in these wastewater treatment
systems, and the specific facts
associated with the impoundment of
potential concern (see 61 FR 42337).
In response to comments, EPA
conducted further analyses of the
potential risks that might arise from
treatment of phenol wastewaters in a
surface impoundment. In these analyses
EPA also included consideration of any
additional risk resulting from
noningestion exposure from
groundwater (e.g., inhalation), as well as
codisposal with other solvent wastes
under evaluation. As described in
section IV.C, these analyses further
confirmed this management practice
presents no significant risks. EPA used
the updated toxicological benchmark
discussed in section III of today's rule
for all additional analyses. The Agency
also used the updated toxicological
benchmark to revise the risk assessment
results for other practices, i.e., storage
and treatment in tanks, and found this
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64396 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
had no significant impact on the risks
(see Table 3).
Based the results of the risk analyses
in the proposal, as well as the updated
evaluations, these spent solvent
residuals are not likely to pose a
significant hazard to human health or
the environment. Therefore, the Agency
continues to believe that a no-list
decision is warranted.
Specific comments. One commenter
supported EPA's decision not to list
wastes from solvent uses of phenol as
hazardous wastes. The commenter
agrees with EPA that phenol does not
satisfy the criteria for listing in 40 CFR
261.11 (a) (3). However, another
commenter stated that there are cases
where phenol is currently used by itself
(without being mixed with other F-
listed wastes) as an industrial solvent
and with this decision "not to list"
phenol as a hazardous waste, EPA
would seem to provide disposal option
"carte blanche" for current users.
Manufacturers can modify their
processes to use these solvents, which
would no longer be considered
hazardous wastes, according to this
commenter.
In response, the Agency believes it
unlikely that facilities would change
their management practices based on
the information collected in the Survey.
The Survey indicated that all
nonvvastewater residuals containing
phenol were managed as hazardous
except one, which is managed by
incineration. Thus, the solvent users
managed their wastes as hazardous
under the existing regulatory
framework. There is no evidence that
any facility that has not modified their
process to use these solvents to date will
do so after a no-list decision. Except for
the facilities that use phenol for
extracting lube oil, most facilities that
use phenol as a solvent use it in
laboratories or other specialty uses, and
the waste solvents are sent for offsite
treatment via incineration as hazardous
waste. EPA has no indication that such
generators could easily modify their use
and accumulation practices in an
attempt to generate nonhazardous
material, nor is there any indication that
facilities would do so.
A third commenter stated that EPA's
decisions regarding plausible
mismanagement scenarios are especially
suspect in the case of phenol, because
phenol is the 33rd highest volume
chemical produced in the United States,
is already widely used, and its use is
projected to increase. The commenter
stated that EPA did not adequately
evaluate groundwater risks posed by
phenol.
EPA disagrees with the commenter's
inference that projected production
increases in phenol are destined for
solvent use. In fact, more than 96% of
the phenol consumed in the U.S. is for
nonsolvent uses (see SRI Chemical
Economics Handbook, 1996). Increasing
demand for products produced from
phenol is due to increases for
production of caprolactam, aniline, and
bisphenol-A, (e.g., see http.7/
www.chemicalweek.com/marketplace/
prod focus.html). Nearly all of the
solvent use of this chemical (>99.9%)
was attributed to the petroleum
industry, of which the Agency
conducted a complete survey. Given
that the major uses of this solvent were
very specialized (i.e., extraction of lube
oil), the Agency is confident that no
other significant uses are likely to exist.
Contrary to the comment, damage from
groundwater contamination was
evaluated for the proposed rule, and a
refined assessment was conducted for
the final rule, and noted in section IV.B.
These analyses did not find significant
groundwater risks (see Table 2), and
details are given in the Supplemental
Risk Assessment document in the
docket.
The commenter also noted that EPA's
Hazardous Waste Characteristic Scoping
Study (November 1996) showed that
phenol releases originated from
nonhazardous waste management units,
principally landfills and surface
impoundments. The Scoping Study,
which expressly excluded product spills
and accident releases, presents clear
evidence of the potential risks posed by
the improper management of phenol
wastes, and the use of nonhazardous
surface impoundments and landfills as
plausible mismanagement scenarios for
phenol and other solvent wastes. The
commenter went on to state that EPA
assumed tanks never leak, and landfills
would never be used, because none
were reported by the 31 facilities
receiving the final questionnaire.
The Agency disagrees that this aspect
of the Characteristic Scoping Study is
relevant to the Solvents Listing
Determination. As EPA noted in the
proposed rule, damage cases reviewed
did not show evidence linking the
phenol contamination at damage sites,
including nonhazardous landfills and
surface impoundments, to phenol use as
a solvent. Without evidence that the
mismanagement of phenol wastes
resulting in contamination is linked to
solvent use, the damage incidents are
not an adequate basis for listing phenol
as a spent solvent. As noted above, the
vast majority of phenol is used for
nonsolvent uses. Therefore simply
pointing to damage case analyses is not
compelling evidence for listing phenol
wastes that result only from its use as
a solvent. If EPA were to determine that
certain industries that use phenol for
nonsolvent uses are mismanaging
wastes and causing significant
environmental problems, then the
Agency would consider other regulatory
approaches. However, EPA's
examination of the limited solvent use
of this chemical indicates that such uses
are not likely ttrgenerate wastes of
concern. Thus, a listing of spent solvent
wastes for this chemical would not be
a practical way to address the types of
environmental concerns raised by the
commenter.
EPA responded to the general issues
of tanks and landfill disposal elsewhere
in today's document. In the case of
phenol, the Agency did not consider the
disposal of phenol-containing
wastestreams in a landfill to be a
plausible management scenario for
several reasons. None of the 38
wastestreams containing spent phenol
reported in the 3007 Survey are
managed in a landfill. One reason for
this is that very few phenol wastes are
solids (most are organic or aqueous
liquids). Only one solid wastestream,
spent carbon, contained significant
levels of phenol. This was sent offsite
for regeneration or incineration. EPA
has no reason to conclude that the
practice of landfilling will increase.
Wastes with higher organic content are
thermally treated, and 92% of the
thermal treatment was conducted in
hazardous waste units or through fuel
blending for future burning. Therefore,
EPA has no basis to project that wastes
with significant phenol concentration
are likely to be placed in a landfill.
Methyl Chloride. Decision. EPA is not
listing wastes from the solvent use of
methyl chloride as hazardous waste
under 40 CFR 261.31. As described in
the proposed rule and as modified by
subsequent analysis in response to
comments, EPA finds treatment in
aerated tanks and surface
impoundments, storage in tanks, or
combustion in a boiler do not present
significant risk. The vast majority of
methyl chloride produced is used as an
intermediate in chemical
manufacturing, and very few uses as a
solvent were identified. Essentially all
of the wastes reported from the solvent
uses of methyl chloride were limited to
two facilities that produce butyl rubber.
While some of the updated lifetime
individual excess cancer risks in Table
3 for storage in tanks and wastewater
treatment in tanks/surface
impoundments were above 1E-06, the
risks are below the IE-OS level typically
used by the Agency for identifying
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Federal Register/Vol. 63. No. 223/Thursday, November 19, 1998/Rules and Regulations 64397
candidate wastes for listing.
Furthermore, as described below, the
consideration of other factors indicate
these risks are not significant.
The high-end risks for storage tanks
(4E-06 from the updated analysis and
2E-06 from the Air Characteristic
approach) are highly likely to be
overestimates, because the analyses
assumed that all of the methyl chloride
in the stored solvent waste would be
released. This assumption is unlikely
for materials being stored expressly to
send for thermal treatment.
Furthermore, these wastes were
reported to be already regulated as
hazardous, and would be subject to
RCRA regulations limiting air releases
under 40 CFR part 264, subpart CC.
The risks found for wastewater
treatment tanks (1E-06 from the
updated analysis, and 1E-07 from the
Air Characteristic approach) are at or
below EPA's presumptive no-list level
of 1E-06, and do not appear of concern.
In addition, these are likely to be
overestimates, because the
concentration modeled for this scenario
was 10 ppm, even though the value was
actually reported as less than 10 ppm.
EPA's updated assessment of the one
wastewater reported to be treated in a
surface impoundment showed a high-
end risk of 4E-06. However the one
impoundment that managed this waste
is already a permitted Subtitle C
hazardous waste unit, and is therefore
subject to regulations limiting air
releases (see 40 CFR part 264, subpart
CC) and groundwater release ( 40 CFR
part 264, subparts F and K,).
In addition, potential air releases from
this industry are being addressed by
other regulations promulgated under the
Clean Air Act (see 61 FR 46906,
September 5, 1996). These regulations
control releases of hazardous air
pollutants from process units, storage
tanks and wastewater treatment
systems. EPA believes that these air
regulations provide a more integrated
approach to controlling air risks than
would be possible under the limited
controls available for air releases under
the RCRA listing program.
Based on the analysis in the proposal,
the updated evaluations, and the other
factors discussed in this document and
the proposal, the methyl chloride
solvent wastes are not likely to pose a
significant hazard to human health or
the environment. Therefore, the Agency
continues to believe that a no-list
decision is warranted.
Specific Comments. One commenter
supported the Agency's decision not to
list methyl chloride. However, another
commenter stated that the Agency left
potential risks posed by the
groundwater exposure pathway
unevaluated by assuming methyl
chloride was managed only in a
permitted surface impoundment, that
tanks never leak, and that landfills
would never be used.
As discussed more detail in the
proposed rule (see 61 FR at 42334-
42335), the Agency did evaluate the
groundwater exposure pathway through
management scenarios where
groundwater exposure was plausible.
Wastes with high organic content were
regulated as hazardous and incinerated.
Waste solids were rarely sent to
landfills, and in these cases the
concentrations of methyl chloride were
negligible. The only wastes sent to
landfills were a small volume of spent
desiccant that contained <5 kg of methyl
chloride, and a larger volume sludge/
ash from a sludge treatment unit which
was reported to have a "trace" amount
of methyl chloride. Given that this
chemical is readily treated by
biodegradation and volatilization in an
aerated biological treatment system, it is
unlikely that any significant levels of
methyl chloride remain in this residual.
EPA believes that these very low
concentration wastes reflect the types of
waste solids that are likely to be sent to
landfills. EPA also notes that other
nonwastewaters containing any reported
levels of methyl chloride (a total loading
of 1.6 kg) were regulated as hazardous
waste, making disposal in an unlined
Subtitle D landfill illegal. Thus,
significant groundwater risks from
landfills are unlikely to occur.
The very limited solvent use of this
chemical, and its unique characteristics
(a gas at room temperature) lead EPA to
conclude that it is unlikely that other
solvent wastes would be generated that
are managed in other surface
impoundments beyond the example
documented in the 3007 survey. As
noted above, this impoundment is a
hazardous waste unit, and is therefore
subject to RCRA regulations limiting
groundwater releases. Furthermore, as
noted in the proposed rule, methyl
chloride is readily treated by
biodegradation and volatilization in
waste water treatment systems, and thus
is unlikely to migrate to the
groundwater. Also, the tendency of
methyl chloride to hydrolyze in water to
methanol suggests that transport to
receptors by groundwater is not likely to
be significant.
One commenter argued that EPA
failed to adequately consider the
formation of products of incomplete
combustion (PICs) for methyl chloride.
The commenter stated that EPA claimed
PIC emissions were not cause for
concern because the reported waste in
question happened to be managed in a
hazardous waste combustor, and
disagreed with EPA's presumption that
this one waste management practice
reported represents current and future
combustion activities.
As noted above, the solvent uses of
methyl chloride are very specialized,
and the number of wastes sent for
incineration are limited. The three
wastes with reported concentrations
that went to thermal treatment were all
classified as hazardous waste and were
treated as such under RCRA regulations.
(Two wastes incinerated were treatment
sludges that were reported to contain no
significant levels of methyl chloride).
Given these reported practices, and the
very limited solvent uses for this
chemical, EPA believes that combustion
of solvent wastes with appreciable
methyl chloride is likely to occur in
RCRA regulated units. Therefore, the
Agency believes its presumption for
management is valid in this case. In
addition, EPA is not aware of any
precise way of predicting the kinds or
levels of PICs that might be generated in
a nonhazardous boiler, especially
because the wastes in question would
make up only a very small fraction of
the wastes being treated.
Nevertheless, EPA did consider the
possibility of PIC formation for
incineration of methyl chloride wastes.
As discussed in the preamble to the
proposed rule (61 FR 42334), the
amount of methyl chloride in the wastes
that are incinerated is extremely small
(i.e., 2 kg). The loading of methyl
chloride sent to a boiler or industrial
furnace (BIF), although larger (i.e., at
2,250 kg) than the amount sent to an
incinerator, is in a waste that is
hazardous due to ignitability and
toxicity characteristics, and therefore
must be treated as hazardous wastes.
This latter waste is generated from the
use of methyl chloride in butyl rubber
manufacturing, and it is unlikely that
such a complex process could (or
would) be modified to avoid generating
waste methyl chloride in association
with high levels of ignitable
hydrocarbons. Thus, combustion in a
RCRA-regulated unit seems likely to
occur for this waste due to the
specialized nature of this solvent use.
These combustion units are operated
according to stringent air emission
standards that limit PIC formation (e.g.,
see 40 CFR part 264, subpart O, for
incinerators and part 266, subpart H, for
Boilers and Industrial Furnaces). EPA
has also proposed revisions to these
standards (see 61FR1538, April 19, 1996
and 62FR24212, May 2, 1997). Given
these facts, as well as the results of the
risk assessment for these wastes, EPA
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64398 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
does not believe that combustion of
these wastes poses a significant risk.
2-Methoxyethanol (2-ME). Decision
EPA is not listing wastes from the
solvent use of 2-methoxyethanol (2-ME)
as hazardous waste under 40 CFR
261.31. As described in the proposed
rule and as modified by subsequent
analysis in response to comments, EPA
found no significant risks from
treatment in aerated tanks or
combustion in a boiler. EPA also
concluded that potential risks from air
releases of 2-ME stored in open
accumulation tanks are also not
significant, because all of the
nonwastewater residuals stored under
this scenario are already regulated as
hazardous waste, either because the
wastes exhibit a characteristic, or
because the 2-ME waste is commingled
with listed wastes. EPA believes that
regulatory controls afforded by the
existing solvent listings and the
characteristics (primarily ignitability)
are sufficiently protective of human
health and the environment.
None of the wastes examined were
sent to land disposal in a landfill or
impoundment. Spent solvent solids are
thermally treated, and wastewaters are
all treated in tanks. In the face of the
existing practices, EPA finds it
implausible that high organic wastes
currently sent to thermal treatment
would be sent to landfills. Essentially
all of the nonwastewater residuals that
contain spent 2-ME are thermally
treated or recovered, and nearly all
(96%) are treated as hazardous waste.
Because all wastewaters are treated in
tanks, EPA also does not expect risks
from surface impoundment management
for these wastes.
Given that nearly all of the
nonwastewater 2-ME residuals are
already being handled as hazardous, or
contain negligible amounts of the
solvent, these spent solvent residuals
are not likely to pose a significant
hazard to human health or the
environment. Furthermore, treatment of
wastewaters in tanks presents no
significant risks. Therefore, the Agency
continues to believe that a no-list
decision is warranted.
More general comments on EPA's
methodology and approach that relate to
2-ME are discussed elsewhere in
today's document. The few comments
specific to 2-ME are discussed below.
Specific comments. One commenter
stated that EPA completely failed to
evaluate potential risks from
groundwater contamination,
notwithstanding three groundwater
contamination incidents involving this
solvent identified by EPA from damage
incidents.
EPA described in the proposed rule
why the damage cases cited by the
commenter were not useful (see 61 FR
at 42332). Of the three problem site
identified, two were old landfills that
received a wide variety of industrial and
municipal wastes, and the use of 2-ME
prior to disposal was impossible to
ascertain. The chemical is widely used
as a fuel additive and as a chemical
intermediate. Thus, the damage could
not be tied to wastes generated from the
use of this chemical as a solvent.
Damage at the third site also could not
be linked to a specific use of 2-ME.
However, this site was a used oil
recycling site, and the contamination
found may be related to the use of 2-
ME as a fuel additive. Furthermore,
none of the reports examined by the
Agency provided any concentration of
2-ME in the groundwater. Thus, the
limited data from the damage incidents
provide no reliable support for listing
wastes from the use of 2-ME as a
solvent. In addition, the industries EPA
identified as solvent users of 2-ME are
not represented in the damage
incidents. Finally, the vast majority of
nonwastewater solvent wastes identified
in the Survey were reported to be
hazardous waste, and could not be
placed in nonhazardous landfills. Thus,
the damage incidents did not provide
useful information on current or likely
future waste management practices.
One commenter argued that EPA's
high-end risk analysis of onsite
accumulation tank storage resulted in a
HQ of 16, well above the HQ of 1 that
typically warrants a hazardous waste
listing. Only by performing the
completely misguided Phase III
assessment was EPA able to arguably
rationalize a no-list decision.
EPA's response to this comment is
similar to the response above to
essentially the same comment raised for
acetonitrile. The apparent risks cited by
the commenter were from an
intermediate stage of the risk
assessment, and did not reflect the fact
that all nonwastewaters were managed
as hazardous waste. EPA concluded that
the management scenario referred to in
the comment (on-site accumulation of
nonwastewaters in unregulated tanks)
does not apply to any 2-methoxyethanol
waste streams.
2-Ethoxyethanol Acetate (2-EEA).
Decision. EPA is not listing wastes from
the solvent use of 2-ethoxyethanol
acetate (2-EEA) as hazardous waste
under 40 CFR 261.31. As described in
the proposed rule and as modified by
subsequent analysis in response to
comments, EPA found no significant
risks from treatment in aerated tanks,
storage in tanks, or combustion in a
boiler. Furthermore, essentially all
(99.8%) of the nonwastewaters were
reported to be hazardous and were
managed as hazardous waste through
some form of thermal treatment.
None of the wastes were reported to
go to land disposal in landfills or
impoundments, and these scenarios
were not modeled. Given the existing
waste management practices, EPA finds
it implausible that high organic waste
solids currently sent to thermal
treatment would be sent to a landfill.
The high percentage of wastes that are
hazardous are precluded from disposal
in an unlined Subtitle D landfill, and
EPA has no evidence to indicate that
spent 2-EEA wastes would be placed in
a landfill. Due to the nature of the
primary industries using 2-EEA as a
solvent (e.g., the semiconductor and
electronics industries), very few
wastewaters are generated. Nearly all of
the wastestreams generated are spent
solvent wastes that undergo some type
of thermal treatment. None of the
wastestreams that were reported in the
3007 Survey go to a surface
impoundment. Any change from the
current treatment in tanks to treatment
in impoundments seems unlikely given
the capital investment associated with
tanks and the liability issues associated
with treatment in a surface
impoundment. These facilities made an
investment in.tank-based systems in the
absence of any listing, and EPA sees no
reason why this would change if the
status quo is not changed, i.e., if the
wastes are not listed. In addition to cost
considerations, some facilities may
perceive other benefits from managing
the waters in tanks, such as the current
exemption from RCRA permitting
requirement for such units (see 40 CFR
264.1 (g) (6)). If hazardous waste were to
be treated in a wastewater treatment
system, impoundments in the system
would require permitting as a Subtitle C
unit. In addition, the use of 2-EEA has
been decreasing in recent years, thus
other new generators of this spent
solvent are unlikely.
Given that nearly all of the
nonwastewater 2-EEA residuals are
already being handled as hazardous, or
contain negligible amounts of the
solvent, these spent solvent residuals
are not likely to pose a significant
hazard to human health or the
environment. Furthermore, treatment of
wastewaters in tanks presents no
significant risks. Therefore, the Agency
continues to believe that a no-list
decision is warranted.
More general comments on EPA's
methodology and approach that relate to
2-EEA are discussed elsewhere in
today's document. The few comments
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related specifically to 2-EEA are
discussed below.
Specific comments. Two commenters
stated that EPA failed to consider in its
risk assessment, that many of the
generators manage 2-EEA with other
solvents associated with this proposed
rule. EPA calculated an HQ for 2-EEA
for on-site accumulation of 0.7. Thus,
additional risk from other solvents
would cause the HQ level to exceed the
threshold of one. One of the
commenters went on to cite examples of
facilities in several industries (e.g.,
printed circuit board manufacturers) at
which multiple solvents were reported.
EPA disagrees with the commenters'
concerns about multiple solvent risks.
First, the comment cited examples
where the hazard quotient would
exceed one at facilities that use more
than one solvent in combination.
However, the use of the chemicals at the
facilities cited by the commenter are not
solvent use, within the Agency's
definition. These facilities used 2-EEA
and other chemicals as components in
formulations. Thus, no spent solvent is
generated and was not included in the
risk assessment.
Furthermore, the HQ value of 0.7
cited by the commenter for on-site
accumulation is likely to be
unrealistically high for the reasons cited
for the Phase II results for acetonitrile.
The key reason is that essentially all
residuals stored prior to thermal
treatment were, in fact, already
hazardous waste. Thus, air emissions
from these wastes are already regulated
under RCRA subpart CC to 40 CFR part
264, making the scenario of storage in
an open tank unrealistic. EPA did not
pursue a third phase of analysis for 2-
EEA because the HQ was below one in
the Phase II evaluation. Furthermore,
the only wastes reported that were not
hazardous consisted of one insignificant
loading (<1 kg), and one waste
characterized as "containers/rags"
which contained very low levels of the •
solvent (<6 kg). Thus, EPA decided
further analysis was. not needed. As
described in the Risk Assessment
section, EPA addressed the general
comment of the impact of multiple
solvents in some wastes by conducting
an assessment of the potential for
cumulative risks.
One commenter stated that the
concentrations of 2-EEA in solvent
nonwastewaters range from 0.1% to
100%. These ranges are not consistent
with the Agency's position that
nonwastewaters would always be
managed as a hazardous waste due to
ignitability, particularly where the
solvent is not co-managed with listed
solvent wastes. The commenter was also
concerned because the concentration of
2-EEA in wastewaters ranges from 200-
20,000 ppm.
While the levels of 2-EEA in solvent
nonwastewaters are variable, the
reported data clearly indicate that
essentially all 2-EEA solvent wastes
generated were hazardous, and that
these were all incinerated. Concerning
the wastewaters, EPA believes the
commenter's concern is unfounded.
EPA's risk assessment included an
analysis of potential risks from air
releases from an aerated wastewater
treatment tank, and found risks to be
well below levels of concern.
Furfural. Decision. EPA is not listing
wastes from the solvent use of furfural
as hazardous waste under 40 CFR
261.31. As described in the proposed
rule and as modified by subsequent
analysis in response to comments, EPA
found no significant risks from
treatment in aerated tanks or surface
impoundments, storage in tanks, or
combustion in boilers. Essentially all of
the solvent use of this chemical (greater
than 99.99%) is in the petroleum
industry as an extractant for lube oil.
Thus, solvent use of furfural is limited,
and the Agency identified only a
handful of wastes derived from this use.
The furfural solvent wastes are
virtually all wastewaters (greater than
99.99%), which were managed in
wastewater treatment systems. One of
the three facility's wastewater treatment
systems uses a surface impoundment,
and EPA's bounding analysis for the
proposed rule showed no risks of
concern from ingestion of groundwater,
or inhalation of possible air releases
(HQ <1; see 61 FRat 42341).
In response to comments, EPA
conducted further analyses of the
potential risks that might arise from
treatment of furfural wastewaters in a
surface impoundment. In these analyses
EPA also included consideration of any
additional risk resulting from non-
ingestion exposure from groundwater
(e.g., inhalation). As shown in Table 3,
the high-end risk analyses showed that
these wastewaters do not present
significant risks via either groundwater
releases (HQ = 0.46), or air releases
(HQ = 0.11).
Based the results of the risk analyses
in the proposal, the updated
evaluations, and the other factors
discussed in this document and the
proposal, the furfural solvent wastes are
not likely to pose a significant hazard to
human health or the environment.
Therefore, the Agency continues to
believe that a no-list decision is
warranted.
General comments on EPA's
methodology and approach that relate to
furfural are discussed elsewhere in
today's document. EPA did not receive
any other specific comments on EPA's
decision not to list furfural solvent
wastes.
Cumene. Decision. EPA is not listing
wastes from the solvent use of cumene
as hazardous waste under 40 CFR
261.31. As described in the proposed
rule and as modified by subsequent
analysis in response to comments, EPA
found no significant risks from
treatment in aerated tanks, storage in
tanks, or combustion in boilers. While
cumene is used in large volumes in the
production of other chemicals, such as
phenol, its use as a solvent is limited.
Essentially all of the wastes containing
cumene are thermally treated as
hazardous or recovered. Small amounts
of wastewaters are sent to treatment
systems, and one resulting sludge was
reported to be landfilled. However, the
amount of cumene in this sludge would
be well below the maximum of 28 kg
that was used in the original solvent
mixture (which contained only 1.7 % of
cumene to start with). Thus, after
treatment, any risks from cumene would
be negligible. Similarly, one wastewater
was reported to undergo treatment in a
surface impoundment, however, as EPA
noted in the proposal, the amount of
cumene in the wastewater was small
(<47 kg), and would be further reduced
by treatment.
In response to comments, EPA
conducted further analyses of the
potential risks that might arise from
treatment of cumene wastewaters in a
surface impoundment. In these analyses
EPA also included consideration of any
additional risk resulting from non-
ingestion exposure from groundwater
(e.g., inhalation during showering). As
shown in Table 2, the revised bounding
analyses showed that these wastewaters
in impoundments do not present
significant risks via either groundwater
releases (HQ = 0.0001), or air releases
(HQ = 0.003). As noted earlier in today's
document, the toxicological values for
cumene were updated during the
comment period. The new benchmarks
were used in the revised analyses, and
were also used to recalculate risks
derived in the proposed rule (see Table
1). The changes reflect greater tolerance
for cumene than the previous
benchmarks, and thus have no impact
on EPA's decision not to list cumene
solvent wastes.
EPA also considered the potential for
cumene to form NAPLs, which might
present special problems in assessing
potential risks. EPA noted in the
proposed rule that cumene's water
solubility is relatively low, such that
NAPLs are theoretically possible.
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However, EPA considered the potential
risks from NAPLs to be very low,
because cumene loading in wastes sent
to land-based disposal was minimal. In
response to comments, EPA provided
further analysis showing that NAPL
formation for these wastes is unlikely
(see section IV.B).
Based the results of the risk analyses
in the proposal, the updated
evaluations, and the other factors
discussed in this document and the
proposal, the cumene solvent wastes are
not likely to pose a significant hazard to
human health or the environment.
Therefore, the Agency continues to
believe that a no-list decision is
warranted.
General comments on EPA's
methodology and approach that relate to
cumene are discussed elsewhere in
today's document.
Cyclohexanol. Decision. EPA is not
listing wastes from the solvent use of
cyclohexanol as hazardous waste under
40 CFR 261.31'. As described in the
proposed rule and as modified by
subsequent analysis in response to
comments, EPA found no significant
risks from accumulation in storage in
tanks or combustion in boilers. The
solvent uses of cyclohexanol are
limited, and few wastes containing
cyclohexanol were reported. All wastes
but one are hazardous waste due to
other waste constituents or properties of
the waste material. The incinerated
material contains low levels of
cyclohexanol (16 kg total loading per
year). The one other waste generated
was reported to go to a nonhazardous
landfill, however, this waste is a small
volume (750 kg) of filter material that
contains negligible level of
cyclohexanol. Given the limited solvent
uses of this chemical, and the
management practices reported, EPA
believes other wastes or management
practices are not likely to be significant.
As noted earlier in today's document,
the toxicological inhalation benchmark
("provisional RfC") for cyclohexanol
was adjusted somewhat based on peer
review comments. Thus, EPA used the
new benchmark to recalculate risks
derived in the proposed rule (see Table
3). The revised HQs remain below one,
and thus the updated health-based
number has no material effect on EPA's
decision not to list cyclohexanol solvent
wastes.
Based the results of the risk analyses
in the proposal, the updated
evaluations, and the other factors
discussed in this document and the
proposal, the cyclohexanol solvent
wastes are not likely to pose a
significant hazard to human health or
the environment. Therefore, the Agency
continues to believe that a no-list
decision is warranted.
More general comments on EPA's
methodology and approach that relate to
cyclohexanol are discussed elsewhere in
today's document.
Isophorone. Decision. EPA is not
listing wastes from the solvent use of
isophorone as hazardous waste under 40
CFR 261.31. As described in the
proposed rule and as modified by
subsequent analysis in response to
comments, EPA found no significant
risks from accumulation in storage in
tanks or combustion in boilers. The
solvent uses of isophorone are limited,
and few wastes containing isophorone
were reported. All wastes but one were
hazardous waste due to mixture with
other listed wastes or the ignitability
characteristic of the waste material. All
wastes were reported to undergo some
form of thermal treatment as a
hazardous waste. Given the limited
solvent uses of this chemical, and the
management practices reported, EPA
believes other wastes or management
practices are likely to be significant.
As noted earlier in today's document,
the toxicological value ("provisional
RfC") for isophorone was adjusted
somewhat based on peer review
comments. Thus, EPA used the new
benchmark to recalculate risks derived
in the proposed rule (see Table 1). The
revised HQs remain below one, and thus
the updated health-based number has
no material effect on EPA's decision not
to list isophorone solvent wastes.
Based on the results of the risk
analyses in the proposal, the updated
evaluations, and the other factors
discussed in this document and the
proposal, the isophorone solvent wastes
are not likely to pose a significant
hazard to human health or the
environment. Therefore, the Agency
continues to believe that a no-list
decision is warranted.
More general comments on EPA's
methodology and approach that relate to
isophorone are discussed elsewhere in
today's document.
2-Methoxyethanol Acetate (2-MEA).
Decision. EPA is not listing wastes from
the solvent use of 2-methoxyethanol
acetate (2-MEA) as hazardous waste
under 40 CFR 261.31. As described in
the proposed rule and as modified by
subsequent analysis in response to
comments, EPA found no significant
risks from storage in tanks or
combustion in a boiler. 2-MEA is
reportedly no longer produced
domestically, and solvent use of this
chemical is limited. The few wastes
generated were classified as hazardous
and were all thermally treated as
hazardous waste. Given the limited and
decreasing use as a solvent, and the
waste information reported, EPA
believes that other wastes and
management practices are unlikely.
None of the wastes were reported to be
disposed of in landfills or
impoundments, and these scenarios
were not modeled.
Given the existing practice, EPA finds
it implausible that high organic waste
solids currently sent to thermal
treatment would be sent to a landfill.
The wastes are hazardous and thus
precluded from disposal in an unlined
Subtitle D landfill. EPA has no evidence
to indicate that spent 2-MEA wastes
would be placed in a landfill. Due to the
nature of the solvent uses reported for
2-MEA (diluent in coating and reaction
media), no wastewaters are generated,
nor were they expected.
Based on the results of the risk
analyses in the proposal, the updated
risk analysis, and other factors noted
above and in the proposed rule, these
spent solvent residuals are not likely to
pose a significant hazard to human
health or the environment. Therefore,
the Agency continues to believe that a
no-list decision is warranted.
More general comments on EPA's
methodology and approach that relate to
isophorone are discussed elsewhere in
today's document. EPA did not receive
any specific comments on EPA's
decision not to list 2-MEA solvent
wastes.
Chemicals with no significant solvent
use. As described in the proposed rule
and reaffirmed in this final decision,
EPA did not find any significant solvent
use for four chemicals: p-
dichlorobenzene, benzyl chloride,
epichlorohydrin, and ethylene
dibromide. All but one are relatively
reactive chemicals, which makes them
unsuitable for most solvent
applications. The other substance, p-
dichlorobenzene, is a solid at room
temperature, limiting its utility as a
solvent. In all cases, the data collected
by the Agency showed that any solvent
use of these chemicals is extremely
limited. Some may perhaps have
specialty applications in laboratories,
but no significant solvent uses were
identified. Any residuals reported from
the 3007 Survey were primarily from
possible solvent use by laboratories and
contain low levels of the chemicals
under study. All were coded as
hazardous, except one dilute
wastewater, and were thermally treated
as hazardous waste.
The Agency received no new
information during the comment period
indicating that these four chemicals,
(benzyl chloride, epichlorohydrin,
ethylene dibromide, and p-
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dichlorobenzene) were used as solvents.
Comments received by EPA on this
issue concurred with the Agency's
decision that these four chemicals are
not used as solvents, and that they
would not fit the description for such a
listing. Based on the analyses and
factors noted above and in the proposed
rule, these spent solvent residuals do
not pose a significant hazard to human
health or the environment. Therefore,
the Agency continues to believe that no-
list decisions for these four chemicals
are warranted.
V. Regulatory Requirements
A. Regulatory Impact Analysis Pursuant
to Executive Order 12866
Executive Order No. 12866 requires
agencies to determine whether a
regulatory action is "significant." The
Order defines a "significant" regulatory
action as one that "is likely to result in
a rule that may: (1) have an annual
effect on the economy of $100 million
or more or adversely affect, in a material
way, the economy, a sector of the
economy, productivity, competition,
jobs, the environment, public health or
safety, or State, local, or tribal
governments or communities; (2) create
serious inconsistency or otherwise
interfere with an action taken or
planned by another agency; (3)
materially alter the budgetary impact of
entitlements, grants, user fees, or loan
programs or the rights and obligations of
recipients; or (4) raise novel legal or
policy issues arising out of legal
mandates, the President's priorities, of
the principles set forth in the Executive
Order."
The Agency estimated the costs of
today's final rule to determine if it is a
significant regulation as defined by the
Executive Order. Because the Agency
has decided not to list as hazardous the
wastes generated from the use of the
solvents evaluated in this rulemaking,
no specific action is required under this
action. As a result, there are no costs
associated with this final rule. This rule
was deemed significant for novel policy
reasons by the Office of Management
and Budget (OMB) and was submitted to
OMB for review.
B. Regulatory Flexibility 'Act
Pursuant to the Regulatory Flexibility
Act (5 U.S.C. 601 et seq., as amended by
the Small Business Regulatory
Enforcement Fairness Act (SBREFA) of
1996) whenever an agency is required to
publish a document of rulemaking for
any proposed or final rule, it must
prepare and make available for public
comment a regulatory flexibility
analysis that describes the effect of the
rule on small entities (i.e., small
businesses, small organizations, and
small governmental jurisdictions).
However, no regulatory flexibility
analysis is required if the head of an
agency certifies the rule will not have a
significant economic impact on a
substantial number of small entities.
SBREFA amended the Regulatory
Flexibility Act to require Federal
agencies to provide a statement of the
factual basis for certifying that a rule
will not have a significant economic
impact on a substantial number of small
entities. The following discussion
explains EPA's determination. This rule
has no effect as the Agency is issuing
this final decision not to list wastes
generated from the use of 14 chemicals
as solvents as hazardous under the
Resource Conservation and Recovery
Act (RCRA). The determinations in this
rule are limited to specific solvent
wastes. The rule does not impose new
burdens on small entities. Therefore, I
hereby certify that this rule will not
have a significant economic impact on
a substantial number of small entities.
This rule, therefore, does not require a
regulatory flexibility analysis.
C. Unfunded Mandates Reform Act
Title II of the Unfunded Mandates
Reform Act of 1995 (UMRA), Public
Law No. 104-4, establishes
requirements for Federal agencies to
assess the effects of their regulatory
actions on State, local, and tribal
governments and the private sector.
Under section 202 of the UMRA, EPA
generally must prepare a written
statement, including a cost-benefit
analysis, for proposed and final rules
with Federal mandates that may result
in expenditures to State, local, and
tribal governments, in the aggregate, or
to the private sector, of $100 million or
more in any one year. Before
promulgating an EPA rule for which a
written statement is needed, section 205
of the UMRA generally requires EPA to
identify and consider a reasonable
number of regulatory alternatives and
adopt the least costly, most cost-
effective, or least burdensome
alternative that achieves the objectives
of the rule. The provisions of section
205 do not apply when they are
inconsistent with applicable law.
Moreover, section 205 allows EPA to
adopt an alternative other than the least
costly, most cost-effective, or least
burdensome alternative if the
Administrator publishes with the final
rule an explanation why that alternative
was not adopted. Before EPA establishes
any regulatory requirements that may
significantly or uniquely affect small
governments, including tribal
governments, it must have developed
under section 203 of the UMRA a small
government agency plan. The plan must
provide for notifying potentially
affected small governments, enabling
officials of affected small governments
to have meaningful and timely input in
the development of EPA regulatory
proposals with significant Federal
intergovernmental mandates, and
informing, educating, and advising
small governments on compliance with
the regulatory requirements.
EPA has determined that this rule
does not include a Federal mandate that
may result in estimated costs of $100
million or more to either State, local, or
tribal governments in the aggregate. The
rule would not impose any federal
intergovernmental mandate because it
imposes no enforceable duty upon State,
tribal or local governments. States,
tribes and local governments have no
compliance costs under this rule. For
the same reasons, EPA also has
determined that this rule contains no
regulatory requirements that might
significantly or uniquely affect small
governments. In addition, as discussed
above, the private sector is not expected
to incur costs exceeding $100 million.
By these findings, EPA has fulfilled the
requirement for analysis under the
Unfunded Mandates Reform Act.
D. Executive Order 12875: Enhancing
the Intergovernmental Partnership
Under Executive Order 12875, EPA
may not issue a regulation that is not
required by statute and that creates a
mandate upon a State, local or tribal
government, unless the Federal
government provides the funds
necessary to pay the direct compliance
costs incurred by those governments, or
EPA consults with those governments. If
EPA complies by consulting. Executive
Order 12875 requires EPA to provide to
the Office of Management and Budget a
description of the extent of EPA's prior
consultation with representatives of
affected State, local and tribal
governments, the nature of their
concerns, copies of any written
communications from the governments,
and a statement supporting the need to
issue the regulation. In addition,
Executive Order 12875 requires EPA to
develop an effective process permitting
elected officials and other
representatives of State, local and tribal
governments "to provide meaningful
and timely input in the development of
regulatory proposals containing
significant unfunded mandates."
Today's rule does not create a
mandate on State, local or tribal
governments. The rule does not impose
any enforceable duties on these entities.
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64402 Federal Register/Vol. 63, No. 223/Thursday, November 19, 1998/Rules and Regulations
It issues a final decision not to list
wastes generated from the use of 14
chemicals as solvents as hazardous
under the Resource Conservation and
Recovery Act (RCRA). Accordingly, the
requirements of section l(a) of
Executive Order 12875 do not apply to
this rule.
E. Executive Order 13045: Protection of
Children From Environmental Health
Risks and Safety Risks
Executive Order 13045: "Protection of
Children from Environmental Health
Risks and Safety Risks" (62 FR 19885,
April 23, 1997) applies to any rule that:
(1) is determined to be "economically
significant" as defined under E.O.
12866, and (2) concerns an
environmental health or safety risk that
EPA has reason to believe may have a
disproportionate effect on children. If
the regulatory action meets both criteria,
the Agency must evaluate the
environmental health or safety effects of
the planned rule on children, and
explain why the planned regulation is
preferable to other potentially effective
and reasonably feasible alternatives
considered by the Agency.
This final rule is not subject to the
Executive Order because it is not
economically significant as defined in
E.O. 12866, and because the Agency
does not have reason to believe the
environmental health or safety risks
addressed by this action present a
disproportionate risk to children. The
Agency performed a risk assessment to
assist in its determination whether to
list or not to list the solvent wastes in
this final rule as hazardous waste. This
risk assessment calculated the potential
risk resulting from the current
management of these wastes to
individuals (including sensitive
populations like children). The Agency
has determined that management of
these solvent wastes as hazardous is not
required and that the environmental
health risks or safety risks addressed by
this action do not have a
disproportionate effect on children.
F. Environmental Justice E.O. 12898
EPA is committed to addressing
environmental justice concerns and is
assuming a leadership role in
environmental justice initiatives to
enhance environmental quality for all
residents of the United States. The
Agency's goals are to ensure that no
segment of the population, regardless of
race, color, national origin, or income
bears disproportionately high and
adverse human health and
environmental impacts as a result of
EPA's policies, programs, and activities,
and that all people live in clean and
sustainable communities. In response to
Executive Order 12898 and to concerns
voiced by many groups outside the
Agency, EPA's Office of Solid Waste
and Emergency Response formed an
Environmental Justice Task Force to
analyze the array of environmental
justice issues specific to waste programs
and to develop an overall strategy to
identify and address these issues
(OSWER Directive No. 9200.3-17). The
Agency has determined that a hazardous
waste listing is not justified for the
wastes examined in this rule. As a
result, no specific action is required
under this rule. It is, therefore, not
expected to result in any
disproportionately negative impacts on
minority or low income communities
relative to affluent or non-minority
communities.
G. Paperwork Reduction Act
This rule does not contain any
information collection requirements
subject to OMB review under the
Paperwork Reduction Act of 1980, 44
U.S.C. 3501 etseq.
H. National Technology Transfer and
Advancement Act
Section 12(d) of the National
Technology Transfer and Advancement
Act of 1995 ("NTTAA"), Pub L. No.
104-113, §12(d) (15 U.S.C. 272 note)
directs EPA to use voluntary consensus
standards in its regulatory activities
unless to do so would be inconsistent
with applicable law or otherwise
impractical. Voluntary consensus
standards are technical standards (e.g.,
materials specifications, test methods,
sampling procedures, and business
practices) that are developed or adopted
by voluntary consensus standards
bodies. The NTTAA directs EPA to
provide Congress, through OMB,
explanations when the Agency decides
not to use available and applicable
voluntary consensus standards. This
action does not involved technical
standards. Therefore, EPA did not
consider the use of any voluntary
consensus standards.
L Executive Order 13084: Consultation
and Coordination With Indian Tribal
Governments
Under Executive Order 13084, EPA
may not issue a regulation that is not
required by statute, that significantly or
uniquely affects the communities of
Indian tribal governments, and that
imposes substantial direct compliance
costs on those communities, unless the
Federal government provides the funds
necessary to pay the direct compliance
costs incurred by the tribal
governments, or EPA consults with
those governments. If EPA complies by
consulting. Executive Order 13084
requires EPA to provide to the Office of
Management and Budget, in a separately
identified section of the preamble to the
rule, a description of the extent of EPA's
prior consultation with representatives
of affected tribal governments, a
summary of the nature of their concerns,
and a statement supporting the need to
issue the regulation. In addition.
Executive Order 13084 requires EPA to
develop an effective process permitting
elected officials and other
representatives of Indian tribal
governments "to provide meaningful
and timely input in the development of
regulatory policies on matters that
significantly or uniquely affect their
communities."
Today's rule does not significantly or
uniquely affect the communities of
Indian tribal governments. As
mentioned above, no specific action is
required by this action. Today's rule
does not create a mandate on State, local
or tribal governments. The rule does not
impose any enforceable duties on these
entities. Accordingly, the requirements
of section 3(b) of Executive Order 13084
do not apply to this rule.
]. Congressional Review Act
The Congressional Review Act, 5
U.S.C. 801 etseq., as added by the Small
Business Regulatory Enforcement
Fairness Act of 1996, generally provides
that before a rule may take effect, the
agency promulgating the rule must
submit a rule report, which includes a
copy of the rule, to each House of the
Congress and to the Comptroller General
of the United States. EPA has submitted
a report containing this rule and other
required information to the U.S. Senate,
the U.S. House of Representatives, and
the Comptroller General of the United
States prior to publication of the rule in
the Federal Register. This action is not
a "major rule" as defined by 5 U.S.C.
804(2).
List of Subjects in 40 CFR Part 261
Environmental protection, Hazardous
materials, Waste treatment and disposal,
Recycling.
Dated: October 30, 1998.
Carol M. Browner,
Administrator.
[FR Doc. 98-30601 Filed 11-18-98: 8:45 am]
BILLING CODE 6560-50-P
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