[Federal Register Volume 63, Number 223 (Thursday, November 19, 1998)]
[Rules and Regulations]
[Pages 64372-64402]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-30601]
[[Page 64371]]
_______________________________________________________________________
Part IV
Environmental Protection Agency
_______________________________________________________________________
40 CFR Part 261
Hazardous Waste Management System: Identification and Listing of
Hazardous Waste, Solvents; Final Rule
Federal Register / Vol. 63, No. 223 / Thursday, November 19, 1998 /
Rules and Regulations
[[Page 64372]]
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 $0.15/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 Street, 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
II. Summary of Proposed Rule
A. Determinations Not to List Solvent Wastes as Hazardous Waste
B. Summary of Risk Assessment Supporting the Proposed Rule
III. Peer Review of Calculated Toxicological 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 6921(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 3001(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, or toxicity).
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
[[Page 64373]]
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 3001(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 (EDF
v. 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. RCRA 3001(e)(2)
directs
[[Page 64374]]
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.
II. 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
of 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
[[Page 64375]]
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 RfD). 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 1E-05) 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 percentile, 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
[[Page 64376]]
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
----------------------------------------------------------------------------------------------------------------
Previous New
provisional provisional
Solvent NOAEL \1\ (mg/m3) toxicological toxicological
benchmark (mg/ benchmark (mg/
m3) m3)
----------------------------------------------------------------------------------------------------------------
Cyclohexanol............................ 0.06.................................. 0.00006 0.00002
Phenol.................................. 19.................................... 0.019 0.006
Isophorone.............................. 37 (LOAEL) \2\........................ 0.0037 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/m\3\ to 0.4 mg/
m\3\. 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.
[[Page 64377]]
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 risk 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
[[Page 64378]]
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="" [[page="" 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="" manner="" 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="" not="" 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.="" [[page="" 64380]]="" 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
[[Page 64381]]
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="" [[page="" 64382]]="" 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="" i.b,="" 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="" [[page="" 64383]]="" 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="" task="" force="" v.="" 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="" not="" project="" landfill="" disposal="" in="" the="" petroleum="" [[page="" 64384]]="" 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,="" sec.="" 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.1).="" 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="" [[page="" 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="" (chemdat8)="" 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="" [[page="" 64386]]="" 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="" solvents="" in="" unit="" bounding="" hq="" \2\="" ``high-end''="" hq="" ------------------------------------------------------------------------------------------------------\2\-------="" tennessee="" eastman..............="" acetonitrile,="" phenol..="" 3.30e-02...........................="" n/a="" \3\.="" exxon="" baytown..................="" methyl="" chloride="" \2\...="" [4.60e-06].........................="" [3.50e-06].="" mobil="" beaumont.................="" furfural,="" phenol......="" 1.20e+00...........................="" 8.00e-01.="" lyondell.......................="" cumene................="" 4.10e-02...........................="" n/a.="" rhone-poulenc..................="" acetonitrile..........="" 6.52e-02...........................="" n/a.="" citgo..........................="" phenol,="" furfural......="" 7.40e-01...........................="" 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="" [[page="" 64387]]="" [graphic]="" [tiff="" omitted]="" tr19no98.000="" [[page="" 64388]]="" [graphic]="" [tiff="" omitted]="" tr19no98.001="" billing="" code="" 6560-50-c="" [[page="" 64389]]="" 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="" sec.="" 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="" [[page="" 64390]]="" 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="" 264.1084(j)).="" 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="" [[page="" 64391]]="" 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="" sec.="" 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="" [[page="" 64392]]="" manufacturer="" already="" has="" ample="" incentive="" to="" modify="" its="" process="" to="" avoid="" the="" cost="" of="" generating="" more="" hazardous="" waste.="" these="" manufacturers="" apparently="" 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="" [[page="" 64393]]="" 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;=""><1 kg).="" thus="" it="" is="" highly="" unlikely="" that="" these="" wastes="" could="" present="" any="" significant="" risk,="" regardless="" of="" whether="" or="" not="" the="" wastes="" were="" designated="" as="" hazardous.="" furthermore,="" the="" commenters'="" calculations="" are="" based="" on="" the="" lowest="" solvent="" concentration="" waste="" being="" mixed="" with="" an="" organic="" chemical="" and="" the="" highest="" solvent="" concentration="" waste="" being="" mixed="" with="" water.="" however,="" most="" of="" the="" lower="" concentration="" solvent="" wastes="" reported="" are="" mixed="" with="" water="" (at="" concentrations="" of="" solvent="" much="" lower="" than="" those="" presented="" by="" the="" commenter),="" are="" managed="" in="" a="" tank-based="" wastewater="" treatment="" system,="" and="" undergo="" biological="" treatment.="" most="" of="" the="" higher="" concentration="" solvent="" wastes="" reported="" are="" mixed="" with="" other="" organics="" and="" are="" managed="" by="" some="" type="" of="" thermal="" treatment="" due="" to="" the="" heating="" value="" of="" the="" waste.="" 3.="" waste-specific="" rationales="" and="" response="" to="" specific="" comments="" acetonitrile.="" decision.="" epa="" is="" not="" listing="" wastes="" from="" the="" solvent="" use="" of="" acetonitrile="" as="" hazardous="" waste="" under="" 40="" cfr="" 261.31.="" as="" described="" in="" the="" [[page="" 64394]]="" 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="" [[page="" 64395]]="" 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="" (acetonitrile="" 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="">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.
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\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.
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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 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
[[Page 64396]]
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 nonwastewater 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://
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 to
generate 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 1E-05 level typically used by the Agency
for identifying
[[Page 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="" [[page="" 64398]]="" 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="" [[page="" 64399]]="" 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="" fr="" at="" 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.="" [[page="" 64400]]="" 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-="" [[page="" 64401]]="" 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,="" or="" 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.="" [[page="" 64402]]="" 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="" 1(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="" et="" seq.="" 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,="" sec.="" 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.="" i.="" 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.="" j.="" congressional="" review="" act="" the="" congressional="" review="" act,="" 5="" u.s.c.="" 801="" et="" seq.,="" 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="">