Federal Register, Volume 59 Issue 245 (Thursday, December 22, 1994)

[Federal Register Volume 59, Number 245 (Thursday, December 22, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-30767]

[[Page Unknown]]

[Federal Register: December 22, 1994]

_______________________________________________________________________

Part II

Environmental Protection Agency

_______________________________________________________________________

40 CFR Part 261 et al.

Hazardous Waste Management System; Identification and Listing of
Hazardous Waste; Dye and Pigment Industries; Hazardous Waste Listing
Determination Policy; and CERCLA Hazardous Substance Designation and
Reportable Quantities; Proposed Rules
ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 261, 271, and 302

[SWH-FRL-5122-5]
RIN 2050-AD80

AGENCY: Environmental Protection Agency.

ACTION: Notice of proposed rulemaking.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) is proposing to
amend the regulations for hazardous waste management under the Resource
Conservation and Recovery Act (RCRA). EPA is listing, as hazardous,
five wastes generated during the production of dyes and pigments
because certain ways of disposing of these wastes may present a risk to
human health and the environment. EPA also is proposing not to list as
hazardous six other wastes from this industry, and to defer action on
three wastes due to insufficient information. The proposal would add
the toxic constituents found in the wastes to the list of constituents
that serve as a basis for classifying wastes as hazardous. This action
also describes EPA's policy on making listing determinations, and the
risk-based criteria used by the Agency.
This action is proposed under the authority of Sections 3001(e)(2)
and 3001(b)(1) of the Hazardous and Solid Waste Amendments of 1984
(HSWA), which direct EPA to make a hazardous waste listing
determination for dye and pigment wastes. If finalized, this regulation
would regulate these wastes as hazardous wastes under Subtitle C of
RCRA. Additionally, this action proposes to designate the wastes
proposed for listing as hazardous substances subject to the
Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA). EPA is not taking action at this time to adjust the one-pound
statutory reportable quantities (RQs) for these substances.

DATES: EPA will accept public comments on this proposed rule and on
EPA's hazardous waste listing determination policy until March 22,
1995. Comments postmarked after this date will be marked ``late'' and
may not be considered. Any person may request a public hearing on this
proposal by filing a request with Mr. David Bussard, whose address
appears below, by January 5, 1995.

ADDRESSES: The official record of this proposed rulemaking is
identified by Docket Number F-94-DPLP-FFFFF and is located at the
following address. The public must send an original and two copies of
their comments to: EPA RCRA Docket Clerk, Room 2616 (5305), U.S.
Environmental Protection Agency, 401 M Street, SW., Washington, DC
20460.
The Docket Number for comments on EPA's discussion of its listing
determination policy (see Section I.B) is F-94-LCN-FFFFF. The public
must send an original and two copies of their comments on EPA's policy
discussion to the above address. Such comments must be submitted
separately from comments on the dye and pigment listing determinations,
and must reference Docket Number F-94-LLCN-FFFFF. Copies of materials
relevant to this proposed rulemaking are located in the docket at the
address listed above. The docket is open from 9 am to 4 pm, Monday
through Friday, excluding Federal holidays. The public must make an
appointment to review docket materials by calling (202) 260-9327. The
public may copy 100 pages from the docket at no charge; additional
copies are $0.15 per page.
Requests for a hearing should be addressed to Mr. David Bussard at:
Characterization and Assessment Division, Office of Solid Waste (5304),
U.S. Environmental Protection Agency, 401 M Street, SW., Washington, DC
20460.

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: Wanda Levine, Office of Solid Waste (5304),
U.S. Environmental Protection Agency, 401 M Street, SW., Washington, DC
20460, (202) 260-7458.
For technical information on the CERCLA aspects of this rule,
contact: Ms. Gerain H. Perry, Response Standards and Criteria Branch,
Emergency Response Division (5202G), U.S. Environmental Protection
Agency, 401 M Street, SW., Washington, DC 20460, (703) 603-8760.

SUPPLEMENTARY INFORMATION: The contents of the preamble to this
proposed rule are listed in the following outline:

I. Background
A. Statutory and Regulatory Authorities
B. EPA's Hazardous Waste Listing Determination Policy
II. Today's Action
A. Summary of Today's Action
1. Confidentiality Claims
2. Summary of Listing Determinations and Deferrals
3. Request for Comment on the Effect of Enforceable EPA/Industry
Agreements on Plausible Mismanagement Analysis and Subsequent
Listing Determinations
B. Dye and Pigment Industries Overview
C. Description of the Process Wastes Identified in Comparison to
those Specified in the Settlement Agreement
D. Description of Health and Risk Assessments
E. Waste-Specific Listing Determination Rationales
III. Waste Minimization
IV. Applicability of Land Disposal Restrictions Determinations
A. Request for Comment on the Agency's Approach to the
Development of BDAT Treatment Standards
B. Request for Comment on the Agency's Approach to the Capacity
Analyses in the LDR Program
V. Compliance Dates
A. Notification
B. Interim Status and Permitted Facilities
VI. State Authority
A. Applicability of Rule in Authorized States
B. Effect on State Authorizations
VII. CERCLA Designation and Reportable Quantities
VIII. Economic Impact Analysis
IX. Executive Order 12866
X. Regulatory Flexibility Act
XI. Paperwork Reduction Act

I. Background

A. Statutory and Regulatory Authorities

These regulations are proposed under the authority of Sections
2002(a) and 3001(b) and 3001(e)(2) of the Solid Waste Disposal Act, 42
U.S.C. 6912(a), and 6921(b) and (e)(2), as amended by the Hazardous and
Solid Waste Amendments of 1984 (HSWA). These statutes commonly are
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) (42 U.S.C. 6901-6992(k)).
Section 102(a) of the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), 42 U.S.C. 9602(a) is
the authority for the CERCLA aspects of this rule.
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.
Hazardous waste is defined at Section 1004(5) of RCRA, 42 U.S.C.
6903(5). 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. In addition, hazardous wastes are
those solid wastes which may pose a substantial present or potential
hazard to human health or the environment when improperly managed.
EPA's regulations establishing criteria for listing hazardous
wastes are codified at Title 40 of the Code of Federal Regulations
(CFR) Sec. 261.11 (40 CFR 261.11). Section 261.11 states three criteria
for identifying characteristics and for listing wastes as hazardous.
First, wastes may be classified as ``characteristic'' wastes if
they have the properties described at 40 CFR 261.21-24 which would
cause them to be classified as having the characteristics of
ignitability, corrosivity, reactivity or toxicity.
Second, wastes may be classified 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, wastes may be listed as hazardous if they contain hazardous
constituents identified in Appendix VIII of 40 CFR part 261 and the
Agency concludes, after considering eleven factors enumerated in 40 CFR
261.11(a)(3), that the waste is capable of posing a substantial present
or potential hazard to human health or the environment when improperly
managed. Such wastes are designated as toxic wastes. 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.
Wastes listed as hazardous are subject to federal requirements
under RCRA for persons who generate, transport, treat, store or dispose
of such waste. Facilities that must meet the hazardous waste management
requirements, including the need to obtain permits to operate, commonly
are referred to as Subtitle C facilities. Subtitle C is Congress'
original statutory designation for that part of RCRA that directs EPA
to issue those regulations for hazardous wastes as may be necessary to
protect human health or the environment. Thus, facilities like
incinerators or landfills that are required to comply with RCRA
requirements for hazardous waste are referred to as Subtitle C
incinerators or landfills.
Subtitle C is codified as Subchapter III of Chapter 82 (Solid Waste
Disposal) of Volume 42 of the United States Code (42 U.S.C. 6921
through 6939(e)). EPA standards and procedural regulations implementing
Subtitle C are found generally at 40 CFR parts 260 through 272.
Solid wastes that are not hazardous wastes may be disposed of at
facilities that are overseen by state and local governments. These are
the so-called Subtitle D facilities. Subtitle D is Congress' original
statutory designation for that part of RCRA that deals with federal
assistance to state and regional planning efforts for disposal of solid
waste.
Subtitle D is codified as Subchapter IV of Chapter 82 (Solid Waste
Disposal) of Volume 42 of the United States Code (42 U.S.C. 6941
through 6949(a)). EPA regulations affecting Subtitle D facilities are
found generally at 40 CFR parts 240 thru 247, and 255 thru 258.
Section 3001(e)(2) of RCRA (42 U.S.C. 6921(e)(2)) requires EPA to
determine whether to list as hazardous wastes generated by various
chemical production processes, including the production of dyes and
pigments.
In June of 1991, EPA entered into a proposed consent decree in a
lawsuit filed by the Environmental Defense Fund, et al. (EDF v. Reilly,
Civ. No. 89-0598 (D.D.C.), hereinafter referred to as the settlement
agreement), in which the Agency agreed to publish a proposed
determination as to whether or not to list as hazardous certain wastes
from the production of dyes and pigments by November 30, 1994 and to
promulgate a final decision by November 30, 1995.
There are three major classes of dyes and pigments: Azo/benzidine,
anthraquinone, and triarylmethane. The settlement agreement specifies
that the listing is to address the azo, monoazo, diazo, triazo,
polyazo, azoic, and benzidine categories of the azo/benzidine dye and
pigment class; the anthraquinone and perylene categories of the
anthraquinone dye and pigment class; and the triarylmethane,
triphenylmethane, and pyrazolone categories of the triarylmethane dye
and pigment class. The settlement agreement also specifies that the
listing is to address the following types of wastes where they are
found: spent catalysts, reactor still overheads, vacuum system
condensate, process waters, spent adsorbent, equipment cleaning sludge,
product mother liquor, product standardization filter cake, dust
collector filter fines, recovery still bottoms, treated wastewater
effluent, and wastewater treatment sludge.
As part of its regulations implementing Section 3001(e) of RCRA,
EPA published a list of hazardous wastes that includes hazardous wastes
generated from non-specific sources and a list of hazardous wastes from
specific sources. These lists have been amended several times, and are
published in 40 CFR 261.31 and 40 CFR 261.32, respectively. In this
action, EPA is proposing to amend 40 CFR 261.32 to add five wastes from
specific sources generated during the production of dyes and pigments.
Those hazardous constituents that are proposed to be included in
Appendix VII to part 261, Basis for Listing Hazardous Waste, also are
proposed to be added to Appendix VIII of Part 261, the list of
Hazardous Constituents, if not already included in this list.
All hazardous wastes listed under RCRA and codified in 40 CFR
261.31 through 261.33, as well as any solid waste that exhibits one or
more of the characteristics of a RCRA hazardous waste (as defined in 40
CFR 261.21 through 261.24), are also hazardous substances under the
Comprehensive Environmental Response, Compensation, and Liability Act
of 1980 (CERCLA), as amended. See CERCLA Section 101(14)(C). CERCLA
hazardous substances are listed in Table 302.4 at 40 CFR 302.4 along
with their reportable quantities (RQs). Accordingly, the Agency is
proposing to list the proposed wastes in this action as CERCLA
hazardous substances in Table 302.4 of 40 CFR 302.4. EPA is not taking
action at this time to adjust the one-pound statutory RQs for these
substances.

B. EPA's Hazardous Waste Listing Determination Policy

EPA believes that it should provide the public with a better
understanding of the basis for EPA's listing decisions. Accordingly,
EPA presents here the general approach the Agency uses for determining
whether to list a waste as hazardous pursuant to 40 CFR 261.11(a)(3).
This presentation focuses on selection of waste management scenarios
used in assessing risk and the use of information on risk levels in
making listing determinations. These elements are an important part of
EPA's general listing policy and critical aspects to the dyes and
pigments listing determination. It is important to note that this
discussion presents EPA's general listing policy and is not a
rulemaking. The Agency may take action at variance with this general
policy. The Agency is seeking comment on its policy in order to get
input from the public, not in order to promulgate binding rules for
listing determinations. The Agency will review any comments received
and may revise its policy based on such comments. However, the Agency
does not intend to respond to comments submitted.
The listing criteria described here focus on several aspects of the
Agency's listing determination process. The discussion is not intended
to cover all potential aspects of these determinations. For example,
analyzing population risk is not included in this presentation. The
Agency solicits comment on how population risks could be included as a
factor in listing determinations. The Agency's approach to calculating
distributions of individual risk values when determining ``high end''
risk and the Agency's position on how far into the future it will
consider risk are not covered in today's notice. The Agency solicits
comment on these factors and their use in listing determinations.
Currently, risk levels (including carcinogen risk, non-carcinogen
risk as determined by hazard quotient (HQ), and ecological risk)
provide one of the principal bases for a listing determination.
However, risk levels themselves do not represent the sole basis for a
listing. Other factors generally are weighed in making a listing
decision. The Agency's listing decision policy uses a ``weight-of-
evidence'' approach in which calculated risk information is a key
factor. Available risk values are assessed with all other data
available to determine whether a waste is or is not a hazardous waste.
The criteria for listing wastes as hazardous are described in 40
CFR 261.11. They are presented in two basic parts: Numeric criteria for
acutely hazardous wastes (defined by 40 CFR 261.11(a)(2)); and criteria
for toxic wastes (defined by 40 CFR 261.11(a)(3)) containing toxic
constituents listed in Appendix VIII to Part 261 (where 11 factors are
considered in determining ``substantial present or potential hazard to
human health and the environment'').
Of these 11 factors, seven deal with risk (constituent toxicity,
concentration, waste quantity, migration potential, persistence,
degradation product potential, and bioaccumulation potential) and are
integrated into the risk values generated. The other four factors
(plausible management, damage cases, coverage of other regulatory
programs, and other factors as may be appropriate) are individual
factors that also are considered in a listing determination. Waste
quantity (specifically, ``de minimis'' amounts of waste) also can be a
special consideration in making a listing determination for a lower
volume wastestream.
1. Selection of Waste Management Scenarios (261.11(a)(3)(vii))
As noted above, one of the many factors that the Agency takes into
account is the ``plausible types of improper management to which the
waste could be subjected.'' 40 CFR 261.11(a)(3)(vii). Exposures to
wastes (and therefore the risks involved) will vary by waste management
practice.
It is important to note that a management scenario need not be in
use currently to be considered plausible by EPA since disposal
practices can and do change over time. Potential future waste
management practices are projected and considered in the risk analysis,
if appropriate. The Agency often projects risks from management that
reasonably could be employed.
a. Factors for Projecting a Plausible Waste Management Scenario.
There are a number of disposal scenarios for wastes not hazardous under
RCRA that are common across industries. These include municipal and
industrial unlined landfills for solid materials, tanks and unlined
surface impoundments for liquids, and boilers for organic solids and
liquids. The Agency will presume that these scenarios are plausible
unless circumstances unique to a particular industry show that one or
more is not plausible for that industry.
The Agency notes that there may exist certain disposal scenarios
not common across industries that could present a greater risk than the
risk from the common plausible management scenarios mentioned above. An
example might be land-spreading sludge from wastewater treatment
facilities. These less common scenarios generally will be considered
plausible only when information on an industry indicates that these
disposal methods currently are being practiced, or there is good reason
to believe they might be practiced in the future.
In determining whether one of the common disposal scenarios is not
plausible, the Agency will consider factors such as the following:
Availability of waste management practices.
There may be practical constraints to the type of waste management
practices available to a category of waste generators. For example, if
facilities in an industry have only a limited amount of land available
to them, then building large surface impoundments to handle wastewaters
may be highly unlikely and would not be considered plausible.
Coverage of the Characterization Program.
Where all, or at least a large percentage, of facilities in an
industrial category can be characterized with respect to waste
management practices, the Agency may be able to do a more refined
analysis of the plausibility of facilities switching from their current
waste management practice to a higher risk waste management practice.
The Agency may determine it more appropriate to estimate risk based on
current management practices where our analysis shows that it is
unlikely that facilities would switch to another management practice.
Effect of Other Regulatory Programs.
Other regulatory programs, for example, the water pollution control
program or air pollution regulatory requirements, can impose legal,
technical, or practical restraints on waste management practices. If
these requirements restrict certain practices (e.g., water treatment
requirements technically and practically might preclude treatment in
surface impoundments) the Agency can use this information to consider
eliminating that disposal practice from consideration.
Management Costs.
Often, the cost of different management scenarios can be a
determinative factor in dictating the plausibility of waste management
scenarios. In the absence of other potential cost factors, such as
liability, the plausibility that a facility would choose a waste
management scenario increases as the expense of that management
practice decreases. Conversely, it is more implausible to assume that a
firm would chose management activities that impose a higher cost (where
cost includes the likelihood of future potential liabilities.) Cost can
be a consideration the Agency uses in choosing which management
scenario to project as a scenario to analyze for determining potential
risk of waste management.
These factors are presented as examples; there may be others
appropriate to specific industries. In characterizing the risks for a
wastestream where more than one disposal scenario is plausible, the
Agency will use the results of the risk assessment for the plausible
scenario that presents the highest risks.
Note that EPA considers the extent to which the plausible
management scenario calculated to cause the highest risk is practiced,
or could be practiced. Management practices the Agency believes
probably would occur infrequently may be less determinative in the
final listing determination process. As the probability that generators
would use a management practice increases, the greater the weight that
set of risk values has in the final listing determination.
2. Risk Levels in Making Listing Decisions
As noted earlier, the Agency's listing determination policy
utilizes a ``weight-of-evidence'' approach in which risk is a key
factor. Risk measurements used include carcinogen risk, non-carcinogen
risk as determined by hazard quotient (HQ), and ecological risk.
However, risk levels themselves do not necessarily represent the sole
basis for a listing. There can be uncertainty in calculated risk values
and so other factors are considered in conjuction with risk in making a
listing decision.
a. Use of Risk Levels in a Listing Decision. EPA's current listing
determination procedure (illustrated in Figure 1) uses as an initial
cancer-risk ``level of concern'' a calculated risk level of 1 x
10^{-5 (one in one hundred thousand) and/or HQs (and/or
environmental risk quotients [EQs]) of 1 at any one point in time. Note
that individual risks can occur at different points in time. For
example, a category of wastestream that is both burned in a boiler by
one facility but placed in a landfill by another would be projected to
cause exposure through both the air and the drinking water pathways. It
is likely that risks from each source will occur at different times,
since air exposures would probably occur sooner than groundwater
exposures. The Agency will take the timing factor into account when
analyzing risk. In accordance with EPA policy, risks from individual
carcinogens generally are added together. Listing decisions from this
risk level of concern generally will be as follows.

BILLING CODE 6560-50-P

TP22DE94.000

BILLING CODE 6560-50-C
(1) Wastestreams for which the calculated high-end individual
cancer-risk level is 1 x 10^{-5 or higher generally are considered
initial candidates for a list decision.
(2) Wastestreams for which these risks are calculated to be 1 x
10^{-4 or higher, or 1 or higher HQs or EQs for any individual non-
carcinogen, or non-carcinogens that elicit adverse effects on the same
target organ, generally will be considered to pose a substantial
present or potential hazard to human health and the environment and
generally will be listed as hazardous waste. Such wastestreams fall
into a category presumptively assumed to pose sufficient risk to
require their listing as hazardous waste. However, even for these
wastestreams there can in some cases be factors which could mitigate
the high hazard presumption. These additional factors, explained below,
also will be considered by the Agency in making a final determination.
(3) Wastestreams for which the calculated high-end individual
cancer-risk level is lower than 1 x 10^{-5 generally are
considered initial candidates for a no-list decision.
(4) Wastestreams for which these risks are calculated to be 1 x
10^{-6 or lower, and lower than 1.0 HQs or EQs for any non-
carcinogens, generally will be considered not to pose a substantial
present or potential hazard to human health and the environment and
generally will not be listed as hazardous waste. Such wastestreams fall
into a category presumptively assumed not to pose sufficient risk as to
require their listing as hazardous waste. However, even for these
wastestreams, in some cases, there can be factors that could mitigate
the low hazard presumption. These also will be considered by the Agency
in making a final determination.
(5) Wastestreams where the calculated high-end individual cancer-
risk level is between 1 x 10^{-4 and 1 x 10^{-6 fall in the
category for which there is a presumption of candidacy for either
listing (risk >10^{-5) or no listing (risk <10^{-5). However,
this presumption is not as strong as when risks are outside this range.
Therefore, listing determinations for wastestreams falling into this
range would always involve assessment of the additional factors
discussed below.
b. Additional Factors.
The following factors will be considered in making listing
determinations, particularly for wastes falling into the risk range
between 1 x 10^{-4 and 1 x 10^{-6:
(1) Certainty of waste characterization;
(2) Certainty in risk assessment methodology;
(3) Coverage by other regulatory programs;
(4) Waste volume;
(5) Evidence of co-occurrence;
(6) Damage cases showing actual impact to human health or the
environment; and
(7) Presence of toxicant(s) of unknown or unquantifiable risk.
(1) Certainty of Waste Characterization
EPA compiles data on the amounts and composition of each
wastestream. Different sources of variability in these data,
variability between facilities, between production processes, between
samples, and in analytical methodologies, exist. All such variability
sources may influence the Agency's decision on how much weight to place
on data collected as a basis for a listing decision.
Budget constraints or sample availability constraints may limit the
size of the database for any one wastestream. In such cases, the Agency
generally assumes that the sample(s) taken are representative of each
like wastestream from that category of generator and that the data,
generated following a QA/QC plan, are ``good'' data. However, EPA will
take uncertainty of the data into account in the listing process.
The Agency sometimes relies on analytical measurements that fall
below the level of an analyst's ability to quantify with certainty the
concentration of the constituent involved (these measurements are
referred to as ``estimated'' or ``J-values'' in listing
determinations). Analytical methods used by the Agency have been
developed with a goal of obtaining quantitative measurements (i.e.,
25% uncertainty or less) at levels of regulatory concern.
Frequently, analytical measurements may detect the presence of
constituents of concern at levels at or below the analytical method's
limit of quantitation. However, for some highly toxic substances
measurements of constituents below the limit of quantitation may be of
toxicological significance and, therefore, potential regulatory
significance.
The limit of quantitation is defined as the level above which
results may be obtained with a specified degree of confidence. In the
case of methods which use mass spectrometric measurements, quantitative
uncertainty is assigned to measurements below the limit of quantitation
(although a positive determination of presence is certain) as follows:
The uncertainty of measurements at the limit of detection
(3 times the standard deviation estimation []) approaches
100% (33).
At the point of reliable detection
(63), the uncertainty of measurement
approaches 50%.
In the area of accurate quantitation (10 to
12), uncertainty approaches 30% to
25%, based on the 99% confidence level of the measurement
uncertainty.
In other words, when the analyte signal is 10 or more times larger
than the standard deviation of the measurements, there is a 99%
probability that the true concentration of the analyte is
30% of the calculated concentration.\1\
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\1\Keith, L.H., Environmental Sampling and Analysis: A Practical
Guide (Chelsea, MI: Lewis Publishers, 1992). See Figure 12, page
110, for the relationship of limit of detection, reliable detection
limit, and limit of quantitation.
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Although the uncertainty of analytical measurements increases as
the limit of detection is approached, the calculated concentrations
obtained may represent the best available measurement of the analyte
present.
It is the Agency's policy on listing determinations that
measurements in the range below the level of quantification but above
the level of detection will be used at the reported quantitation level
for risk analysis purposes. However, the Agency generally will consider
the uncertainty associated with measurements below the quantitation
level and assess the impact of that level of uncertainty on a listing
decision. Increasing uncertainty of a measurement may increase the
importance of other factors in making a listing determination.
(2) Certainty in Risk Assessment Methodology
Uncertainty can exist in the methodologies and data used to conduct
both the toxicity assessments and the fate and transport exposure
models employed in risk assessments. Toxicity assessment methods
sometimes rely on animal or cellular models to predict a chemical's
effect on humans or animals. Direct toxicity testing of a chemical is
not always available. For some of these chemicals, structure/activity
relationships can be used to predict the toxicity of the substance
involved. In these cases, the Agency considers what degree of
uncertainty can exist in that analysis when making listing
determinations. Similarly, some fate/transport models make use of an
increased amount of input data or can involve actual verification. For
those models, uncertainty in exposure analysis is decreased. The Agency
weighs the relative uncertainty of the predictive models when
generating risk assessments and making listing determinations.
(3) Coverage by Other Regulatory Programs
Listing decisions can be strongly influenced by the effect of other
regulatory requirements on the wastestreams involved. Where another
Federal or State program or other RCRA requirements clearly will
provide the type of control needed to eliminate the risk associated
with a certain type of waste management, a RCRA listing may be
considered unnecessary or redundant.
Other Federal or State programs.
If other Federal or State programs clearly regulate risk associated
with the wastestream, listing may not be necessary to eliminate risk.
For example, if the Office of Air and Radiation within EPA has issued
an NESHAP to control emissions of a constituent, it may be unnecessary
to consider risk from inhalation of that constituent in making listing
determinations. In some cases, another regulatory program may be in the
process of developing such regulatory requirements. If this program is
under statutory requirements or Court Order, EPA may consider these
regulatory requirements to be forthcoming and, in some cases, may defer
to them in listing determinations, even where such regulatory coverage
is several years away. If this program is under no statutory or legal
deadline, no deference typically will be given to projected future
regulatory coverage from other programs.
(4) Waste Volume
Waste volume is, in fact, part of a risk-level calculation. Risk is
projected based on the volume of waste involved. However, volume of
waste is also a factor EPA may consider when the projected risk falls
in a marginal risk range.
(5) Evidence of Co-occurrence
Virtually all wastestreams EPA assesses are complex mixtures of
constituents. Where possible, the Agency calculates potential risk for
all measured pollutants. Where more than one risk value for
carcinogenicity is calculated, concern about overall wastestream
effects increases and the Agency will consider that risk additive.
However, where sampling and analysis data show compelling evidence that
the constituents cannot or do not occur together in the wastestream or
at the receptor, the Agency generally will only consider the risk
associated with individual constituents.
(6) Damage Cases
For each listing determination, EPA seeks data on damage cases.
These are cases in which some prior waste management practice has
resulted in environmental harm. Where there has been a clear case of
harm, the data suggest the management of that waste has already damaged
human health or the environment in some way, and that such damage could
occur again. Depending on the number and severity of the damage cases
and the potential for these damages to happen again, adverse damage
cases may provide a ``stand alone'' reason for listing the waste.
Where damage cases appear to contradict the risk analysis, EPA will
try to determine the reason and use that assessment in the overall
listing decision.
(7) Unknown or Unquantified Risk
Not all constituents in a complex wastestream can be analyzed for
risk. Hazard data may not be available either directly or through
mechanisms such as structure/activity relationships, or they may be in
a form which is not considered usable by EPA. In the cases where some
constituents are present but no risk levels can be assigned to them,
the Agency considers the potential for these constituents to be
hazardous.
As stated above, use of these additional factors is not limited to
cases in which the risk levels fall between 10^{-4 and 10^{-6.
Pursuant to EPA's listing determination policy ``weight-of-evidence''
approach, the Agency will consider these factors, as appropriate, even
where risk levels fall in the presumptive list or presumptive no-list
levels.

II. Today's Action

A. Summary of Today's Action

1. Confidentiality Claims
The hazardous waste listings proposed here are based in part upon
data claimed as confidential by certain dye and pigment manufacturers.
Although EPA intends to publish information derived from these data
claimed as confidential (to the extent relevant to the proposed
listing), the Agency is unable to do so at the present time. Therefore,
this proposed rule is being published without some of the information
that supports the Agency's proposal. Where that information is missing
from text, it is noted in the text. Whenever EPA is unable to include
pertinent data in a table, the following statement appears in a
footnote: ``Relevant data are not included at the present time due to
business confidentiality concerns.'' EPA is pursuing avenues to allow
publication of the information, and intends to supplement the public
record prior to issuing a final listing.
2. Summary of Proposed Listing Determinations and Deferrals
In today's notice, EPA is proposing to add five wastes generated
during the production of dyes and pigments to the lists of hazardous
wastes in 40 CFR 261.32. A summary of the waste groupings proposed for
listing are provided below with their proposed corresponding EPA
Hazardous Waste Numbers.

K162 Wastewater treatment sludge from the production of azo pigments.
K163 Wastewaters from the production of azo pigments.
K164 Wastewater treatment sludge from the production of azo dyes,
excluding FD&C colorants.
K165 Wastewaters from the production of azo dyes, excluding FD&C
colorants.
K166 Still bottoms or heavy ends from the production of triarylmethane
dyes or pigments.
The Agency has determined that these wastes meet the criteria for
listing set out in 40 CFR 261.11. Section II.E. of this preamble
presents waste characterization, waste management, and risk assessment
data, which are the bases for the Agency's proposal to list or not to
list the wastes studied in this rulemaking.
Upon promulgation of these proposed listings, all wastes meeting
the listing descriptions would become hazardous wastes and would
require treatment, storage, or disposal at permitted facilities.
Residuals from the treatment, storage, or disposal of the wastes
included in this proposed listing also would be classified as hazardous
wastes pursuant to the ``derived-from'' rule (40 CFR 261.3(c)(2)(i)).
For example, ash or other residuals from treatment of the listed wastes
would be subject to the hazardous waste regulations. Also, 40 CFR
261.3(a)(2)(iv) (the ``mixture'' rule) provides that, with certain
limited exceptions, any mixture of a listed waste and a solid waste is
itself a RCRA hazardous waste.
However, when these wastes are recycled as described in 40 CFR
261.2(e)(1)(iii) or 261.4(a)(8), they are not solid wastes and are not
subject to hazardous waste regulations. For example, if a waste is
collected and returned in a closed-loop fashion to the same process,
the waste is not regulated. To meet the exemption, the manner in which
a material is recycled must meet the three key requirements outlined in
the rules and in 50 FR 639 (January 4, 1985): (1) The material must be
returned to the original process from which it was generated without
first being reclaimed; (2) the production process to which the
materials are returned must use raw materials as principal feedstocks;
and (3) the material must be returned as a substitute for raw material
feedstock in the original production process. (The regulations contain
other recycling exclusions as well, but the provisions referenced above
are the principal ones most likely to be applicable to the wastes at
issue in this proposal.) EPA is proposing to amend Appendix VII and
Appendix VIII to 40 CFR part 261 to add constituents contained in the
above wastestreams which were found to pose risk.
The Agency requests comments on the proposed listing of the above
wastes, and on the option of not listing these wastes.
This action also proposes not to list as hazardous six wastestreams
generated during the production of dyes and pigments:
Wastewaters from the production of triarylmethane dyes and
pigments (excluding triarylmethane pigments using aniline as a
feedstock).
Wastewater treatment sludge from the production of
triarylmethane pigments using aniline as a feedstock.
Wastewaters from the production of triarylmethane pigments
using aniline as a feedstock.
Wastewaters from the production of anthraquinone dyes and
pigments.
Wastewaters from the production of FD&C colorants.
Dusts and dust collector fines from the manufacture of
dyes and pigments.
The Agency requests comments on the proposal not to list the above
wastes and on the option of listing these wastes.
Because the Agency does not have sufficient sampling information on
which to base a proposed listing determination, the Agency proposes to
defer a determination of whether to list wastewater treatment sludge
from the production of triarylmethane dyes and pigments (excluding
triarylmethane pigments using aniline as a feedstock), as well as spent
filter aids, diatomaceous earth, or adsorbents from azo, anthraquinone,
or triarylmethane dyes, pigments, or FD&C colorants. The Agency intends
to obtain such sampling information and issue a supplemental notice
making a proposed determination on whether to list the wastes as
hazardous. The Agency also is deferring a proposed listing
determination for wastewater treatment sludge from the production of
anthraquinone dyes and pigments due to lack of health effects
information on two constituents, leucoquinizarine and 1-
aminoanthraquinone, that were found in the wastestream. The Agency
requests any information that commenters may have on the toxicology of
these constituents, including the existence of any toxic analogs for
leucoquinizarine and 1-aminoanthraquinone. EPA will evaluate carefully
all public comments and information received in response to this
notice. Particular notice will be paid to any data which tend to
support or refute a finding of risk to human health and the
environment. Based on comments received, EPA may choose, rather than
deferring, to promulgate a final determination to either list or not
list wastewater treatment sludge from the production of anthraquinone
dyes and pigments as hazardous under RCRA.
The Agency also requests comments on the data used in this
proposal, the methodology and assumptions used in the risk assessment,
the waste groupings chosen by the Agency and other analyses supporting
the proposed listings.
3. Request for Comment on the Effect of Enforceable EPA/Industry
Agreements on Plausible Mismanagement Analysis and Subsequent Listing
Determinations
The Agency is interested in innovative ways of conducting listing
determinations that could assure environmental protection with less
cost than full regulation as a hazardous waste. One approach on which
the Agency seeks comment involves enforceable agreements between EPA
and the regulated community.
The Agency is seeking comment on whether enforceable agreements
between EPA and industry that restrict the use of certain waste
management practices could affect the Agency's plausible mismanagement
analysis and, in turn, affect the Agency's listing determination.
Specifically, the Agency seeks comment on whether EPA should pursue
such agreements with respect to either the dye and pigment wastes that
the Agency is proposing to list in this notice (or, additionally those
it proposes not to list). The Agency seeks comment on whether the
Agency should decide not to list such wastes (or retain a no-list
decision) if the agreements ensure that the wastes will not be managed
in a manner that poses unacceptable risk.
A decision not to list based on such enforceable agreements could
be based on the view that management practices that are prohibited in
an enforceable agreement are not ``plausible'' because facilities
within an industry covered by an enforceable agreement are unlikely to
violate that agreement; i.e., use a risky management practice,
especially if the agreement were to contain monetary or other sanctions
for a breach or violation. Waste management practices that are not
plausible because they are prohibited by such an agreement arguably
need not be considered by the Agency in determining whether the waste
poses ``a substantial present or potential hazard to human health or
the environment when improperly treated, stored, transported, or
disposed of, or otherwise managed.'' (See discussion of selection of
waste management scenarios at I.B.1.) Thus, if a waste does not pose an
unacceptable risk if managed in accordance with an enforceable
agreement, the Agency could determine that the waste should not be
listed as hazardous. The Agency requests comment on the use of such an
approach as part of the listing determination for wastes generated
during the production of dyes and pigments, including those proposed to
be listed and/or proposed not to be listed in today's notice.
For such an approach to be workable, the EPA believes that the
following basic principles must apply:
(1) All of the companies that generate the wastestream at issue
must be party to the agreement;
(2) To ensure that the agreement will adequately deter prohibited
waste management practices, the agreement should be enforceable in
court and should contain provisions requiring payment of sufficient
penalties or damages if the agreement is violated;
(3) The agreement should eliminate management practices that pose
an unacceptable risk;
(4) The agreement should contain provisions that would account for
new entrants; and
(5) The agreement should promote waste minimization.
Section 7003 of RCRA may provide EPA with authority under
appropriate circumstances to enter into such agreements on consent.
Section 7003(a) of RCRA authorizes EPA to issue orders requiring such
action as may be necessary upon receipt of evidence that the past or
present handling, storage, treatment, transportation, or disposal of
any solid waste or hazardous waste may present an imminent and
substantial endangerment to human health or the environment. EPA also
has the authority to settle claims under RCRA section 7003 by entering
into a consent decree or agreement. In addition, the Agency has
inherent authority to enter into contracts that are not prohibited by
law. See generally, Kern-Limerick, Inc. v. Scurlock, 347 U.S. 110
(1954). Such inherent authority also may be available to enter into
such agreements.
EPA believes that such an approach may be feasible for the wastes
generated during the production of dyes and pigments because such
wastes are generated by a relatively small number of facilities, and
the likelihood of expansion in this industry does not appear to be
great. Such an approach may not be feasible in an industry with a
greater number of facilities or in an industry that is expanding.
Additionally, it may not be a valid approach for an industrial sector
in which the wastes generated are so hazardous, move off-site in such a
fashion, or require such detailed controls that EPA wants the full
regulatory controls and civil and criminal authorities that follow from
full Subtitle C regulation.
The Agency requests comments on the feasibility of entering into
and enforcing such agreements with industry. The Agency also requests
comment on how such agreements would account for entrance into the
market of new facilities that generate the waste at issue (e.g., add
new elements to the agreement, issue unilateral order under RCRA
Section 7003). The Agency also requests comment on alternative
innovative approaches to listing determinations.

B. Dye and Pigment Industries Overview

The dye and pigment industries are comprised of three separate
industries, represented by three different trade associations. The
Color Pigment Manufacturers Association (CPMA) represents pigment
manufacturers, the Ecological and Toxicological Association of the
Dyestuffs Manufacturing Industry (ETAD) represents dye manufacturers,
and the International Association of Color Manufacturers (IACM)
represents food, drug, and cosmetic (FD&C) colorants manufacturers.
Dyes are intensely colored or fluorescent organic substances that
impart color to a substrate by selective absorption of light.\2\ When a
dye is applied, it penetrates the substrate in a soluble form, after
which it may or may not become insoluble. Dyes are retained in the
substrate by physical absorption, salt or metal-complex formation,
solution, mechanical retention, or by the formation of ionic or
covalent chemical bonds.\3\
---------------------------------------------------------------------------

\2\``Pigments--A Primer,'' reprinted from American Ink Maker,
June 1989, Color Pigment Manufacturers Association.
\3\Kirk-Othmer Encyclopedia of Chemical Technology--Volume 8,
``Dyes and Dye Intermediates.''
---------------------------------------------------------------------------

Dyes are used to color fabrics, leather, paper, ink, lacquers,
varnishes, plastics, cosmetics, and some food items. Dye manufacture in
the U.S. includes more than 2,000 individual dyes, the majority of
which are produced in quantities of less than 50,000 pounds. In 1990,
total U.S. dye production was 258 million pounds. In 1991, there were
approximately 33 manufacturing plants operated by 20 companies that
produce either azo, anthraquinone, or triarylmethane dyes.\4\
---------------------------------------------------------------------------

\4\1992 RCRA Section 3007 Questionnaire Data.
---------------------------------------------------------------------------

Pigments possess unique characteristics that distinguish them from
dyes and other colorants. Pigments are colored, black, white, or
fluorescent particulate organic or inorganic solids, usually insoluble
in, and essentially physically and chemically unaffected by, the
vehicle or substrate in which they are incorporated. The primary
difference between pigments and dyes is that during the application
process, pigments are insoluble in the substrate. Pigments also retain
a crystalline or particulate structure and impart color by selective
absorption or by scattering of light. With dyes, the structure is
temporarily altered during the application process, and imparts color
only by selective absorption.\5\
---------------------------------------------------------------------------

\5\``Pigments--A Primer,'' reprinted from American Ink Maker,
June 1989, Color Pigment Manufacturers Association.
---------------------------------------------------------------------------

Pigments are used in a variety of applications; the primary use is
in printing inks. There are fewer pigments produced than dyes, though
pigment batches are generally larger in size. The U.S. total 1990
pigment production volume of approximately 415 million pounds is
composed of 300 million pounds of inorganic pigments and 115 million
pounds of organic pigments.\6\ In 1991, there were approximately 27
domestic manufacturing plants operated by 20 companies\7\ producing
organic pigments subject to the settlement agreement.
---------------------------------------------------------------------------

\6\CPMA meeting presentation, August, 1991.
\7\1992 RCRA Section 3007 Questionnaire Data.
---------------------------------------------------------------------------

FD&C colorants are dyes and pigments that have been approved by the
Food and Drug Administration (FDA) for use in food items, drugs, and/or
cosmetics. Typically, FD&C colorants are azo or triarylmethane dyes and
are similar or identical to larger-volume dye products not used in
food, drugs, and cosmetics. Manufacture of FD&C colorants is identical
to that for the corresponding dye or pigment, except that the colorant
undergoes additional purification. Each FD&C colorant batch is tested
and certified by the FDA. In 1991, there were approximately 7 domestic
manufacturing plants operated by 5 companies\8\ producing FD&C
colorants subject to the EDF settlement agreement.
---------------------------------------------------------------------------

\8\1992 RCRA Section 3007 Questionnaire Data.
---------------------------------------------------------------------------

This proposal addresses the three chemical classes of organic dyes
and pigments specified in the settlement agreement: azos,
anthraquinones, and triarylmethanes.
Azos are the largest and most versatile chemical class. The various
azo chemical structures are readily synthesized, typical product
application methods are not complex, and a broad range of colors can be
produced with excellent fastness properties. Azo colorants are used in
essentially all organic dye applications, including textiles, paper,
inks, coatings, plastics, and leather.
Pyrazolones are a subset of azo dyes and pigments, named for the
substituted pyrazolones that are used as coupling agents. The
pyrazolone subclass is comprised mainly of yellow, orange, and red azo
dyes and pigments.
Pyrazolone dyes and pigments are used primarily in textiles and
plastics, respectively.
Despite high costs, anthraquinones are an important group of dyes
due to superior fastness. They have applications on cotton, cellulose,
and synthetic fibers. They have good affinity for the substrate, level
dyeing power, and excellent fastness. Anthraquinone pigments are
chemically identical to the corresponding dyestuffs and also exhibit
high fastness properties. They are used primarily in automotive paints.
There are many more anthraquinone dyes than pigments. Most
anthraquinone dyes have not been developed into pigments due to
technical constraints, as well as competition from less expensive
substitutes.
Perylene pigments, a subset of the anthraquinone chemical class,
provide an economical alternative to heavy metal-containing red
pigments. Their excellent thermal stability and fastness properties
meet the standards for automotive finishes and other high-quality
coatings.
Triarylmethanes are characterized by their brilliancy of hue,
intensity of color, and low fastness properties. Triarylmethane dyes
typically are used in the textile industry and in the production of
pigments. Pigments typically are used in the production of printing and
duplicating inks.

C. Description of the Process Wastes Identified in Comparison to Those
Specified in the Settlement Agreement

Based on the Agency's study of the dye and pigment industries, EPA
has concluded that many of the dye and pigment processes within each of
the three chemical classes generate very similar wastestreams. Because
of the similarity of wastestreams associated with the manufacture of
each class of dye or pigment (i.e., azo, anthraquinone, and
triarylmethane), EPA combined closely related wastestreams into ``waste
groupings,'' and proposed one hazardous waste listing description and
waste code for each of these groupings. Although, given time and
resource constraints, EPA was not able to sample wastestreams generated
from the production of each distinct product within a particular waste
grouping, the sampling data and raw material and process chemistry
information that EPA collected support the waste groupings EPA has
established.
The constituents and their concentrations in a waste will
determine, in turn, the nature of the toxicity of the waste. EPA is
required to consider the nature and toxicity of a waste in making
listing determinations pursuant to 40 CFR 261.11. Given that
similarities between wastes will result in a similar listing
determination pursuant to the factors in EPA's regulations, it is
reasonable to group wastes for the purpose of making listing
determinations. Further, grouping similar waste matrices (i.e.,
wastewaters or sludges) will facilitate the development of land
disposal treatment standards (see 40 CFR part 268).
Listing determinations were made on each waste grouping. For
example, all wastewaters resulting from the production of azo pigments
are proposed to be listed as K163 hazardous wastes. Other wastewater
groupings for which listing determinations were made include
wastewaters resulting from the production of azo dyes, excluding FD&C
colorants (proposed as K165), wastewaters resulting from the production
of anthraquinone dyes and pigments, and wastewaters resulting from the
production of FD&C colorants.
In addition, wastewaters generated from the production of
triarylmethane dyes and pigments are grouped together under one waste
grouping due to the similarity of these wastes, with the exception of
wastewaters from the production of triarylmethane pigments using
aniline as a feedstock. Wastewaters from the production of
triarylmethane pigments using aniline as a feedstock were found to be
significantly different in chemical composition from other
triarylmethane dye and pigment processes and, therefore, were placed in
a separate waste grouping.
Triarylmethane pigments using aniline as a feedstock are
manufactured at two facilities in the country. Only two triarylmethane
products are made at each of these facilities and one is used as an
intermediate for the second. The process used in manufacturing these
pigments is a batch process but is operated throughout the year. Only
two primary reactants are used at these facilities, unlike other dye
and pigment operations where hundreds of raw materials often are used
at one site. As a result, these reactants are present in the wastewater
at high concentrations.
Thus, wastewaters from the production of triarylmethane dyes and
pigments were divided into two categories for purposes of making a
listing determination: (1) Wastewaters from the production of
triarylmethane dyes and pigments, excluding triarylmethane pigments
using aniline as a feedstock, and (2) wastewaters from the production
of triarylmethane pigments using aniline as a feedstock.
The wastewater categories include mother liquors generated from
product filtration, filter washwaters, equipment and floor cleaning
washwaters, break waters, spent scrubber waters, and other process
waters. Treated wastewater effluent also is captured by these
wastewater groupings. Although EPA did not sample wastewater following
treatment, treated wastewater would be expected to contain the same or
fewer hazardous constituents and the same or lower concentrations of
such constituents than untreated wastewater. Thus, if not listed before
treatment, such wastewater is presumed not to meet the Agency's
criteria for listing after treatment. Furthermore, any wastewater
listed as hazardous before treatment would continue to be regulated as
hazardous waste after treatment.
Wastewater treatment sludges were grouped in a similar manner to
wastewaters. Wastewater treatment sludges generated from the dye and
pigment industries include any sludges generated during the
pretreatment or treatment of dye and pigment wastewaters. This includes
pretreatment sludge generated from filtration and precipitation in
equalization and neutralization basins, sludges from powdered activated
carbon or other adsorbent treatments, and primary and secondary
biological treatment sludges. Sludge groupings defined for purposes of
listing determinations include wastewater treatment sludge from the
production of azo pigments (proposed as K162), wastewater treatment
sludge from the production of azo dyes, excluding FD&C colorants
(proposed as K164), wastewater treatment sludge from the production of
anthraquinone dyes and pigments, wastewater treatment sludge from the
production of triarylmethane dyes and pigments, excluding
triarylmethane pigments using aniline as a feedstock, and wastewater
treatment sludge from the production of triarylmethane pigments using
aniline as a feedstock. These groupings are justified because, as was
true within the wastewater grouping, the sludges covered by each sludge
waste group exhibit similarities in constituent concentrations.
Distillation bottoms from dye and pigment manufacturing are
generated during raw material and solvent recovery operations. The
Agency determined that still bottoms from dye and pigment manufacturing
are generated only during recovery operations associated with the
manufacture of triarylmethane dyes and pigments. Therefore, the
following waste grouping was developed to address distillation bottoms
from the dye and pigment industries: Still bottoms or heavy ends from
the production of triarylmethane dyes or pigments (proposed as K166).
The Agency grouped spent filter aids, diatomaceous earth, or
adsorbents used in the production of azo, anthraquinone, or
triarylmethane dyes, pigments, or FD&C colorants into one waste
grouping because these wastes all adsorb unreacted raw materials, by-
products, and impurities and are generated in physically similar forms.
Because the constituent composition of these filter aids varies
depending on raw materials used, the Agency does not, at this time,
have sufficient data to fully characterize this waste grouping. To
further support a listing determination on these wastestreams, the
Agency intends to collect additional information which will allow
assessment of these wastes either as a single waste grouping or,
alternatively, as several separate groupings.
Dusts and dust collector fines are generated primarily during
drying, grinding, and blending operations used in manufacturing both
dyes and pigments. These wastestreams were grouped because they all are
comprised primarily of product dust.
Product standardization filter cake probably is generated during a
final purification step following product standardization. Information
obtained during the industry study does not confirm the existence or
description of this wastestream. However, filter cakes generated during
product purification are comprised of spent filter aids, diatomaceous
earth, or other adsorbent, along with product impurities and,
therefore, will be characterized with the spent filter aids wastestream
described above.
Information relevant to this discussion is not included at the
present time due to business confidentiality concerns.
Therefore, the Agency is including the spent catalyst wastestreams
with the spent filter aids, diatomaceous earth, or adsorbents used in
the manufacture of azo, anthraquinone, or triarylmethane dyes,
pigments, or FD&C colorants waste group. The Agency did not encounter
any traditional catalysts (i.e., chemicals used to enhance a reaction
without being consumed) used in dye and pigment manufacturing.
Vacuum system condensate, reactor still overhead, and equipment
cleaning sludge, are not generated in dye and pigment manufacturing.
The following table summarizes each of the wastestreams identified
in the settlement agreement, and describes their coverage in the
listing determinations proposed in today's rulemaking:

Table II-1.--Settlement Agreement Wastestreams
------------------------------------------------------------------------
Wastestreams identified in the Coverage in today's proposed
settlement agreement rulemaking
------------------------------------------------------------------------
Product mother liquor.............. Addressed as a wastewater for each
Process waters industry segment, including azo,
Treated wastewater effluent anthraquinone, and triarylmethane
dyes and pigments (K163, K165).
Wastewater treatment sludge........ Addressed as wastewater treatment
sludge for each industry segment,
including azo, anthraquinone, and
triarylmethane dyes and pigments
(K162, K164).
Recovery still bottoms............. Still bottoms from triarylmethane
dyes and pigments (K166).
Spent filter aids.................. Addressed for the industries as a
whole.
Dust collector fines............... Addressed for the industries as a
whole.
Product standardization filter cake Not explicitly generated.
Spent catalysts.................... Not explicitly generated but
included with spent filter aids.
Vacuum system condensate........... Not generated by these industries.
Reactor Still Overhead
Equipment Cleaning Sludge
------------------------------------------------------------------------

D. Description of Health and Risk Assessments

In determining whether waste generated from the production of dyes
and pigments meets the criteria for listing a waste as hazardous as set
out at 40 CFR 261.11, the Agency evaluated the potential toxicity and
intrinsic hazard of constituents present in the wastestreams, the fate
and mobility of these chemicals, the likely exposure routes, the
current waste management practices, and plausible management practices.
A quantitative risk assessment was conducted for those constituents and
wastestreams where the available information made such an assessment
possible.
1. Human Health Criteria and Effects
The Agency uses health-based levels, or HBLs, as a means for
evaluating the level of concern of toxic constituents in various media.
In the development of HBLs, EPA first must determine exposure levels
that are protective of human health and then apply standard exposure
assumptions to develop media-specific levels. EPA uses the following
hierarchy for evaluating health effects data and health-based standards
in establishing chemical-specific HBLS:
a. Use the Maximum Contaminant Level (MCL) or proposed MCL (PMCL)
as the HBL for the ingestion of the constituent in water, when it
exists. MCLs are promulgated under the Safe Drinking Water Act (SWDA)
of 1974, as amended in 1986, and consider technology and economic
feasibility as well as health effects.
b. Use Agency-verified Reference Doses (RfDs) or Reference
Concentrations (RfCs) in calculating HBLs for noncarcinogens and
verified carcinogenic slope factors (CSFs) in calculating HBLs for
carcinogens. Agency-verified RfDs, RfCs, and CSFs and the bases for
these values are presented in the EPA's Integrated Risk Information
System (IRIS).
c. Use RfDs, RfCs, or CSFs that are calculated by standard methods
but not verified by the Agency. These values can be found in a number
of different types of Agency documents and EPA uses the following
hierarchy when reviewing these documents: Health Effects Assessment
Summary Tables (HEAST); Human Health Assessment Group for Carcinogens;
Health Assessment Summaries (HEAs) and Health and Environmental Effects
Profiles (HEEPs); and Health and Environmental Effects Documents
(HEEDs).
d. Use RfDs or CSFs that are calculated by alternative methods,
such as surrogate analysis, including structure activity analysis, and
toxicity equivalency.
All HBLs and their bases for this listing determination are
provided in a document entitled ``Dye and Pigment Waste Listing Support
Health Effects Background Document'' (RTI,1994), which can be found in
the RCRA docket for this rule at EPA Headquarters (see ADDRESSES
section).
Acute toxicity data such as lethal doses for the oral and dermal
routes and lethal concentrations for the inhalation route also were
evaluated for all analytes in the record samples. These data also are
presented in the Health Effects Background Document prepared for this
rule.

Use of Metabolic Products

There are three compounds commonly identified in the record samples
for which EPA has found no reliable health effects data. These
compounds are: Acetoacet-o-anisidide (AAOA), acetoacet-o-toluidide
(AAOT), and acetoacetanilide (AAA). Because of the lack of health
effects data on these compounds, the Agency explored the use of
metabolic pathway information to develop toxicologic values. This
approach involves the use of health effects information for compounds
expected to follow a similar metabolic pathway to those of the three
chemicals of concern to estimate toxicity.
The metabolic pathways for the class of compounds identified as
aromatic amines have been extensively studied, and acetylation and N-
hydroxylation have been identified as initial metabolic reactions of
this class of compounds. Using this information, the Agency proposes to
use the toxicity of aniline to represent the toxicity of AAA and the
toxicity of 2-aminotoluene to represent the toxicity of AAOA and AAOT.
The Agency has assumed a direct quantitative relationship between the
constituents of concern (i.e., AAOA, AAOT, AAA) and these compounds
(i.e., aniline, 2-aminotoluene) that follow a similar metabolic route.
In humans as much as 60 percent of aniline that is absorbed is
oxidized in a dose-dependent manner to give o- and p-aminophenol, the
first step in amide formation for this pathway. The metabolites of
these products include acetylated arylamines, and are responsible for
the toxicity of aniline.
Acetoacetanilide (AAA) is a structural analog of aniline and the
metabolic pathways are expected to be similar. Since the acetyl group
is already part of AAA, initial acetylation may be considered complete.
Because the metabolic conversions occur on a molar basis and the
doses in laboratory studies are reported as parts per million, the
difference in molecular weight must be considered. Also, since only 60
percent of the aniline is expected to be metabolized by the acetylation
pathway and AAA is acetylated in its original form, the toxicity of AAA
is expected to be proportionally greater than the toxicity of aniline.
Therefore, the HBL for AAA is estimated to be 0.003 mg/L as compared to
0.006 mg/L for aniline.
Acetoacet-o-toluidide (AAOT), and acetoacet-o-anisidide (AAOA) are
structural analogues of 2-aminotoluene, and the metabolic pathways are
expected to be similar to those previously described for aniline. Since
the acetyl group is already part of AAOT and AAOA, initial acetylation
may be considered complete.
Because the metabolic conversions occur on a molar basis and the
doses in laboratory studies are reported as parts per million, the
difference in molecular weight must be considered. Also, since only 25
percent of the aminotoluene is expected to be metabolized by the
acetylation pathway, and AAOT and AAOA are acetylated in their original
forms, their toxicities are expected to be proportionally greater than
the toxicity of 2-aminotoluene. Therefore, the HBLs for AAOT and AAOA
are estimated to be 0.00004 mg/L and 0.00005 mg/L, respectively, as
compared to 0.0001 mg/L for 2-aminotoluene.
2-Methoxyaniline also has been identified in the azo pigment
wastestream. 2-Aminotoluene has been selected as the surrogate for the
toxicity of 2-methoxyaniline, because of the structural similarity of
the compounds and the similarity of metabolic mechanisms described
above. The Agency requests comment on the use of metabolic pathway
information to determine health effects, and on alternate approaches.

2. Coeluting Compounds

A number of compounds detected in the wastes generated from dye and
pigment manufacture coelute (i.e., overlap) on the Gas Chromatography/
Mass Spectrometry (GC/MS) curve, making it impossible to confirm the
concentration and, in some cases, the presence of the individual
coeluting compounds. For example, the three constituents, 2- and 4-
aminoaniline, and 2-methoxyaniline, coelute on the GC/MS curve. The
coelution is such that the presence of 2- and 4-aminoaniline is
indistinguishable, yet the presence of 2- methoxyaniline can be
verified. This occurs because the curve for 2-methoxyaniline contains
an extra peak in addition to the peaks that overlap with 2- and 4-
aminoaniline. However, the individual contributions to the total
concentration found in the waste can not be established.
Because the contributions from the individual contaminants can not
be established, the Agency assumed that any of the three contaminants
could be present at 100 percent of the concentration detected. The
Agency evaluated all coeluting compounds independently in the risk
assessment and used the highest risk calculated for the compounds to
ensure the risk was not underestimated.
However, 2-methoxyaniline is the expected contaminant in wastes
generated from facilities that manufacture azo pigments using
acetoacet-o-anisidide (AAOA) as a raw material because 2-methoxyaniline
is an expected hydrolysis product of AAOA (refer to Section II.E,
Wastewater Treatment Sludge from the Production of Azo Pigments, K162,
for a discussion on the hydrolysis of AAOA). Therefore, for wastes
generated from the manufacture of azo pigments using AAOA as a raw
material, the Agency conducted the risk assessment for these coeluting
compounds based on toxicity information for 2-methoxyaniline (see
discussion of metabolic products, above, and the Dye and Pigment Waste
Listing Support Health Effects Background Document for discussions on
the toxicity surrogate used for 2-methoxyaniline).
A second set of coeluting compounds consists of the three isomers
2-, 3-, and 4-aminotoluene. The presence of the three isomers was
confirmed when detected, and the combined concentration of the three
compounds was quantified. Because the contributions from the individual
contaminants can not be established, any one of the coeluting
contaminants could be present at 100 percent of the concentration
detected. Therefore, the Agency evaluated coeluting compounds with
health-based levels independently in the risk assessment and used the
highest risk calculated by the constituents, in this case 2-
aminotoluene, to ensure that risk was not underestimated. The volume of
2-aminotoluene consumed as a raw material, based on 1991 RCRA Section
3007 Questionnaire data, is approximately 9 times that of the other
isomers. In addition, aromatic amines with substitutions in the 2- and
4- positions of the aromatic ring are used in the manufacture of azo
dyes much more frequently than those substituted in the 3- position.
Therefore, any impurities or breakdown products from aromatic amines
are likely to be substituted in the 2- and 4- positions.
1,2-diphenylhydrazine and azobenzene also coelute on the GC/MS
curve. Both compounds are likely oxidation products of aniline, and may
be present in the waste as reaction by-products. In addition to the
uncertainty in establishing concentrations for each of the two
compounds, the chemical pathway from aniline to these oxidation
products suggests that either contaminant may be present at all or part
of the concentration detected. The Agency evaluated these coeluting
compounds independently and used the highest risk calculated by the
compounds to ensure the risk was not underestimated.
As with azobenzene and 1,2-diphenylhydrazine, diphenylamine and N-
nitrosodiphenylamine coelute on the GC/MS curve and are likely by-
products resulting from the oxidation of aniline. As stated above, the
Agency evaluated these coeluting compounds independently and used the
highest risk calculated by the compounds to ensure the risk was not
underestimated.
The Agency requests comments on the approach used to assess risk
when compounds that coelute were detected in the wastestream, and on
alternative approaches that commenters may develop.

3. Risk Analysis

Risk Characterization Approach

The risk characterization approach follows the recent EPA Guidance
on Risk Characterization (Habicht, 1992) and Guidance for Risk
Assessment (EPA Risk Assessment Council, 1991). The guidance specifies
that EPA risk assessments will be expected to include (1) the central
tendency and high-end portions of the risk distribution, and (2)
important subgroups of the populations such as highly susceptible
groups or individuals, if known. In addition to the presentation of
results, the guidance also specifies that the results portray a
reasonable picture of the actual or projected exposures with a
discussion of uncertainties. These documents are available in the
public docket for this action (see ADDRESSES section).

Individual Risk

Individual risk descriptors are intended to convey information
about the risk borne by individuals within a specified population and
subpopulations. These risk descriptors are used to answer questions
concerning the affected population, and the risk for individuals within
a population of interest. The approach used in this analysis for
characterizing baseline individual risk included: (1) Identifying and
describing the population of concern for an exposure route; (2)
determining the sensitivity of the model parameters used in the risk
estimation; (3) estimating central tendency and high-end values for the
most sensitive parameters in the risk estimation procedures; and (4)
calculating individual risk for likely exposure pathways that provides
a characterization of the central tendency and high-end risk
descriptor.

Risk Assessment

The results of the risk assessment are presented in waste-specific
risk tables in each of the basis for listing sections (Section II.E.).
The risk tables include the following information: Constituents of
concern; estimated human health risk associated with the current and
plausible management scenarios; high, low, and average concentrations
of constituents found in this wastestream; the number of samples in
which the constituent was detected; notes regarding ``J-values'' (see
Section II.B on Data Uncertainties); and industry-submitted data.
In addition to those compounds presented in the waste-specific risk
tables, the Agency's characterization data include a number of
compounds identified as present in the waste but for which no health
benchmarks exist. In addition, other compounds which do have health
benchmarks have been identified in these wastes but were dropped from
further consideration following the risk screening because the risks
were projected to be below levels of concern. The risk tables presented
in this preamble do not contain these additional constituents. The
complete list of constituents found in each of the wastes generated
from the manufacture of dyes and pigments, an explanation of the risk
screening process, and an explanation of EPA's development of the
target analyte list are presented in the Listing and Health Effects
Background Documents for this proposed rule, which are located in the
RCRA Docket for this rulemaking (See ADDRESSES section).
The analysis of risk was developed using both the input of derived
or measured toxicological information and the modeling of exposure from
baseline (or current) waste management practices and other plausible
management scenarios. Pursuant to the Agency's regulations on listing
hazardous wastes, EPA considers the ``plausible types of improper
management to which the waste could be subjected'', 40 CFR
261.11(a)(3)(vii). Thus, plausible management is one of the waste
management scenarios used by EPA to assess the risks to human health
and the environment from the disposal of the wastes under
consideration.
The choice of ``plausible management'' depends on a combination of
factors which are discussed in Section II.A, ``EPA's Listing
Determination Process.'' The following discussion explains the
plausible management scenarios used to assess risk for each of the
waste groups addressed in this proposal. The Agency requests comment on
its choice of plausible management scenarios and on the possibility of
using alternative plausible management scenarios.

Sludges and Other Solid Materials

The plausible management scenario used to assess risks for the
wastewater treatment sludges from the production of azo dyes and
pigments (K162 and K164), and still bottoms or heavy ends from the
production of triarylmethane dyes and pigments (K166) was disposal in
an on-site monofill. Disposal in an on-site monofill for these waste
categories results in the highest adverse exposure of sensitive
individuals or populations. For wastewater treatment sludges from azo
dye production (K164), this plausible management scenario (i.e., on-
site monofill) currently is practiced.
The Agency determined that disposal in an on-site monofill is a
plausible management scenario for wastewater treatment sludges from azo
pigment production (K162) and still bottoms or heavy ends from the
production of triarylmethane dyes and pigments (K166), for the
following reasons:
On-site monofills have been used by industry to dispose of
wastewater treatment sludge from the manufacture of dyes and pigments;
Most of the still bottoms generated from the production of
triarylmethane dyes and pigments are high-volume wastestreams for which
on-site monofills are a plausible management option; and
On-site monofills can be a lower-cost disposal option.
Therefore, there is a potential for monofills to be constructed and
used in the future, by either dye or pigment manufacturers to dispose
of wastewater treatment sludges or other high-volume solid wastes.
For wastewater treatment sludge from the production of
triarylmethane pigments using aniline as a feedstock, the plausible
management was determined to be the current management, blending with
non-hazardous fuel. Currently, 100% of this waste is sent off-site for
non-hazardous fuel blending. The Agency believes that this waste will
continue to be managed in this manner because the relatively high
organic content of the waste gives the material value as a fuel
ingredient. Therefore, generators of the waste have an economic
incentive to continue fuel blending. For comparison purposes, the
Agency also projected the risks from managing this wastestream in a
municipal landfill (from release of contaminants into ground water) and
in an on-site boiler (from release of contaminants into the air).
The primary exposure pathway considered from disposal of solid
materials in both unlined municipal landfills (evaluated as the
baseline management practice for K162, K164, and K166) and monofills
(evaluated as plausible management practices for K162, K164, and K166)
is direct ingestion of drinking water from residential wells near the
disposal site. Because of the widespread practice of daily cover,
indirect air pathways and surface erosion and runoff were not evaluated
for municipal landfills. For on-site monofills, however, the
presumption of no daily cover was used, and risks associated with
indirect pathways were evaluated.
In addition to estimating potential risks from waste disposed in an
unlined municipal landfill, the Agency evaluated risks from municipal
landfills meeting the minimum requirements for a Subtitle D landfill
(56 FR 50978, 1991). These requirements include daily cover, flexible
membrane liner, leachate collection system, clay liner, and final cap
and cover. The results of these analyses can be found in the Risk
Assessment for Dye and Pigment Waste Listing Determination. This
document is available in the RCRA public docket (see ADDRESSES
section).
A dilution factor based on the ratio of the volume of the waste to
the volume of co-disposed municipal waste and daily cover was used to
estimate the concentrations of the constituents of concern in the
landfill. The concentrations of the constituents measured in the waste
were multiplied by this dilution factor to determine the concentration
of the constituents in the landfill. The concentrations of the
constituents in the landfill leachate were estimated using Toxicity
Characteristics Leaching Procedure (TCLP) data submitted by industry
for selected constituents (3,3'-dichlorobenzidine, aniline, 4-
chloroaniline, and 2- and 4-aminotoluene), or when TCLP data were not
available, by using a soil-water partitioning equation.
EPA used the following linear partition equation (Dragan, 1988)
with an adjustment to relate sorbed concentration to total waste
concentration.

CL = CW/[Foc * Koc + O * S/Bd]

where CL=leachate concentration
CW=waste concentration
Foc=fraction organic carbon
Koc=organic carbon partitioning coefficient
O=porosity
S=fraction water content
Bd=bulk density

The physical properties of the waste used in this equation (i.e.,
bulk density, fraction organic carbon) were obtained either from the
Agency's record samples when available, or from the 1991 RCRA Section
3007 Questionnaire responses.
The volume of leachate and rate of ground-water recharge were
estimated using the HELP model. The HELP model uses site-specific
precipitation values and standard assumptions for the characteristics
of municipal waste to estimate infiltration and recharge rates. For the
evaluation of dye and pigment wastes in municipal landfills, annual
precipitation rates for sites near all dye and pigment facilities were
ranked. Charlotte, North Carolina was selected as representative of the
median precipitation value for the areas near dye and pigment
facilities, and Charleston, South Carolina, was selected as
representative of sites with high annual rainfall potential. The
default meteorologic conditions for these locations in the HELP model
were used to determine the infiltration and recharge rates used in the
ground-water modeling.
The distance to the receptor wells near the municipal landfill used
in the ground-water modeling were obtained from the survey of well
distances conducted for the Background Document for EPACML: Finite
Source Methodology (EPA, 1992). The value selected as representative of
the average condition is the 50th-percentile value for well distance
(438 m), and the value for the high-end (close) condition (48 m) is the
95th-percentile value.
The Agency used the MULTIMED groundwater model to simulate the
subsurface dilution and attenuation of the leachate constituents in
order to estimate the concentration of constituents at the hypothetical
residential wells. The Agency then calculated risks to an individual,
assuming the residents using this well on average consume 1.4 L/day of
contaminated water, or 2 L/day for higher consumptions. Values of 9 or
30 years were used for the average and high-exposure duration
estimates. The formulae used and a more detailed discussion of the
application of these models to the waste samples can be found in the
Risk Assessment for Dye and Pigment Waste Listing Determination,
available in the RCRA public docket (see ADDRESSES section).
For on-site monofills, the leaching analysis was the same as for
municipal landfills except that the waste concentrations are not
diluted in the monofill.
The distance to the nearest receptor wells near the on-site
landfill used in the ground-water modeling were obtained from a
telephone survey of 9 city planning offices and a review of site visit
reports and site maps. The value selected as representative of the
average condition is the 50th-percentile value for well distance (163
m) and the value for the high-end (close) condition (16 m) is the
closest value. The Risk Assessment for Dye and Pigment Waste Listing
Determination for this rulemaking contains a more detailed discussion
of these values. This document is available in the RCRA public docket
(see ADDRESSES section).
In addition to direct ingestion of contaminated drinking water,
additional pathways were evaluated depending on the characteristics of
the waste and management practices evaluated. These pathways included
inhalation pathways from airborne particulates and volatiles released
from the monofills, and indirect exposure pathways such as the
ingestion of vegetables grown in soil contaminated by runoff from the
on-site landfill and/or dermal exposure due to direct contact with
contaminated soil. The algorithms used for the estimation of risks due
to indirect exposures were taken from the Methodology for Assessing
Health Risks Associated with Indirect Exposure to Combustion Emissions
(U.S. EPA, 1990) as modified by the September 24 draft of Addendum:
Methodology for Assessing Health Risks Associated with Indirect
Exposure to Combustion Emissions. Working Group Recommendations (U.S.
EPA, 1993) and the Risk Assessment Guidance for Superfund (RAGS):
Volume I--Human Health Evaluation Manual (Part B, Development of Risk-
base Preliminary Remediation Goals) (U.S. EPA, 1991), and Dermal
Exposure Assessment: Principles and Applications. Interim Report (U.S.
EPA 1992) for dermal exposures to water. These documents are available
in the public docket for this rule (see ADDRESSES section).
The air pathways were evaluated using the CHEMDAT 7 air emission
model to determine the emission rates for volatile constituents from
the landfill, tanks, and storage bins. The Fugitive Dust Model (FDM)
was used to determine the emission rates for particulates. These
emissions were coupled with dispersion coefficients to determine the
ambient air concentrations and the rate of deposition of the waste
constituents onto the nearby soil, vegetable gardens, watersheds, and
water bodies. The distances to air receptors are assumed to be similar
to those used for the ground-water wells. The meteorologic locations
used for the air modeling were selected by a procedure similar to that
used to select the ground-water locations. The annual average wind
speed, temperature, and precipitation values for 34 sites near dye and
pigment facilities were evaluated to determine three sites believed to
represent a range of conditions to be examined in greater detail.
Hourly meteorological data for five years were ranked for these three
sites to select the location and year of the data to be used in the air
modeling. For the average case, Huntington, West Virginia was selected.
For the high-end case, Charlotte, North Carolina was selected.
An on-site boiler (as the plausible management scenario) also was
evaluated for exposure through the air pathway for still bottoms
generated from the production of triarylmethane dyes and pigments
(K166), and for wastewater treatment sludge from the production of
triarylmethane pigments using aniline as a feedstock. The boiler was
characterized as a small non-hazardous boiler based upon Agency
information and industry-supplied data in the RCRA Section 3007
Questionnaire data. The meteorologic data used to characterize the
dispersion were determined based upon a distribution of meteorologic
data collected for sites near existing dye facilities. These data are
ranked by year and location, and the 50th- and 90th-percentile year and
location were selected for the central and high-end dispersion
modeling. The air dispersion was estimated using the COMPDEP model to
estimate air concentrations and wet and dry deposition of the
constituents on nearby soil, vegetables and water bodies. The air
concentrations and deposition data also were used to evaluate indirect
exposures.

Wastewaters

For wastewater streams (K163, K165, and wastewaters from the
production of triarylmethane dyes and pigments) the Agency determined
that treatment in surface impoundments represents the plausible
management scenario because, since surface impoundments currently are
in use or planned at several dye facilities, and waste management
practices in the dye and pigment industries are generally similar, the
Agency believes that pigment manufacturers may employ surface
impoundments in the future. In addition, facilities currently
manufacturing dyes also could manufacture pigments in the future and
manage wastewaters from pigment production in surface impoundments.
The baseline management practice evaluated for these wastewater
streams (i.e., K163, K165, and wastewaters from the production of
triarylmethane dyes and pigments) was treatment in tanks. Thus, for
wastewaters, the modeling included direct and indirect exposures to
volatile emissions from surface impoundments and tanks and direct and
indirect exposures to contaminants that may leach into ground water
from unlined surface impoundments. The air emissions from tanks were
estimated using the CHEMDAT 7 air emission model and the dispersion of
these emissions was estimated using the Industrial Source Complex
Model-Long Term, Version 2 (ISCLT2) air dispersion model. The
meteorologic locations used for estimating the emissions and
dispersions were the same locations selected for use with air models
for volatile emissions from landfills. Very few inhalation health-based
levels are available for constituents found in dye and pigment
wastewaters. Risk from direct inhalation exposure to wastes disposed in
surface impoundments was estimated to be less than one-in-a-million for
all constituents. Results from air emission modeling for tanks are
presented in the Risk Assessment Background Document for the Proposed
Rule in the RCRA Docket at EPA Headquarters (see ADDRESSES section).
Since the constituents in these wastes are highly soluble, leaching
from unlined impoundments was evaluated. The concentration of the
constituents in the leachate was assumed to be equal to the
concentration in the wastewater.
To estimate the concentration of constituents at the hypothetical
residential well, the Agency attempted to use the MULTIMED model to
simulate the subsurface attenuation and dilution of the surface
impoundment leachate. However, there are limitations of the MULTIMED
model that preclude its use in this analysis. These include the large
volume of leachate estimated to be released from the surface
impoundment and a conservative approach to predict the horizontal
transport of the leachate within the aquifer. This resulted in an
infiltration rate that is so high that it overwhelms the aquifer and
dilution was not expected. Therefore, to evaluate risk for those
wastewaters that the Agency is proposing to list, the Agency assumed
for this proposal that a dilution and attenuation factor (DAF) of 100
is achievable during migration to the nearest drinking water well. The
Agency's toxicity characteristic (TC) rule (55 FR 11798, 1990) adopts a
DAF of 100 to estimate the subsurface fate and transport between an
unlined landfill and a receptor drinking water well. For purposes of
the risk analyses, the concentrations in the residential wells near the
on-site disposal facility were estimated to be equal to 0.01 times the
concentrations measured in the wastewater. The residents using this
well are assumed on average to consume 1.4 L/day or 2L/day of
contaminated water for an exposure duration of 9 years or 30 years.
The Agency believes that it is more reasonable to use the TC rule
approach to support a proposed determination to list, rather than
developing a model more sophisticated than the MULTIMED model because
the Agency believes a more sophisticated analysis would suggest greater
estimated risks than the analysis using a DAF of 100 for the following
reasons. First, the DAF of 100 was derived for the TC rule for a range
of municipal landfill leachate volumes that are generally lower than
leachate volumes from surface impoundments. Surface impoundment DAFs
are expected to be lower (and risks subsequently higher) compared to
landfill DAFs as a result of both the liquid in the impoundment and
subsequent increase in hydraulic head. Second, in the TC analysis, the
location of the receptor well was varied anywhere within the extent of
the contaminant plume. For listing determinations, the Agency generally
assumes that the well is located on the centerline of the plume. This
assumption would lead to a lower DAF and higher risks. Thus, because
the use of the TC DAF of 100 underestimates risk, use of the TC to
estimate risk can support a proposal to list. A more sophisticated
model would show only higher risk numbers. The wastewaters that the
Agency proposes not to list were evaluated using MULTIMED and creating
a bounding estimate. The Agency believes that it is reasonable to use
the MULTIMED model to support this proposed determination not to list
certain wastewaters because it overestimates risks.

Ecological Risks

In addition to evaluating the risk to human health, the analysis
also estimates risks to fish and wildlife from exposure to dye and
pigment wastes. The concentrations of contaminants of concern in water
bodies near dye and pigment waste facilities were estimated using the
indirect exposure methodology and a few high-end input parameters. As a
screening analysis, the estimated surface-water concentrations were
compared with the National Ambient Water Quality Criteria (NAWQC), or
LC50 values for bluegill and/or rainbow trout if NAWQC were not
available. The risks to terrestrial and avian species were evaluated by
comparing the waste concentration with the oral rat LD50, dermal
rabbit LD50, any available avian LD50 values, and if
available, a Lowest Observed Adverse Effects Level (LOAEL). Aniline
from the manufacture of triarylmethane pigment using aniline as a
reactant was the only compound identified as a potential risk to the
aquatic or terrestrial environment by this method. Details of these
analyses are presented in the Risk Assessment for Dye and Pigment Waste
Listing Determination available in the public docket (see ADDRESSES
section).
The Agency requests comments on methodology used by the Agency in
selecting plausible mismanagement scenarios and assessing risks and on
the plausible management scenarios selected for the wastestreams
generated from the manufacture of dyes and pigments.

E. Waste-Specific Listing Determination Rationales

1. Wastes From the Production of Azo Pigments
a. Wastewater treatment sludge from the production of azo pigments
(K162).

Summary

EPA is proposing to list as hazardous wastewater treatment sludges
from the production of azo pigments. This wastestream meets the
criteria set out at 40 CFR 261.11(a)(3) for listing a waste as
hazardous and is capable of posing a substantial present or potential
hazard to human health or the environment. Based on ingestion of
contaminated ground water, EPA calculated high-end individual cancer-
risk levels for six hazardous constituents that are equal to or exceed
1E-4 for carcinogens or have HQs equal to or greater than 1 for non-
carcinogens for the plausible management practice, an on-site monofill.
The combined carcinogenic risk for multiple co-existing constituents in
this wastestream is projected to be 6E-3 for the on-site monofill. In
addition, a combined risk of 1E-4 for multiple co-existing contaminants
were identified for the baseline management practice, a municipal
landfill. Calculated risks exceeding 1E-4 also were identified from
exposure to four contaminants through ingestion of contaminated
vegetables or through dermal contact with contaminated soil. Three
additional contaminants pose calculated individual risks between 1E-4
and 1E-6 for the on-site monofill, and 4 contaminants pose calculated
risks between these levels for the municipal landfill. Six contaminants
pose calculated individual risks between 1E-4 and 1E-6 from exposures
through indirect pathways.

Table II-2.--Waste Characterization and Risk Estimates--K162--Wastewater Treatment Sludge From the Production of Azo Pigments
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline management Plausible management Waste characterization
-----------------------------------------------------------------------------------------------------------------------
Municipal landfill*** On-site monofill***
Constituents of concern --------------------------------------------------------------- Avg. High Low
Central conc. conc. conc. # of pts Notes
Central tendency High end tendency High end
--------------------------------------------------------------------------------------------------------------------------------------------------------
Aniline......................... Risk<1E-6 Risk=1E-6 Risk=1E-5 Risk=6E-5 f.n. f.n. f.n. f.n.......... .............
2- & 4-Aminoaniline/ P2- Risk=6E-6 Risk=3E-5 Risk=3E-6 Risk=3E-4 7.17 ....... ....... 1 of 5....... J, S
Methoxyaniline*.
2- & 4-Aminotoluene**........... Risk<1E-6 Risk<1E-6 Risk=1E-5 Risk=3E-5 1.3 1.5 1.2 3 of 8....... j(3), I(3)
Acetoacet-o-anisidide (AAOA).... Risk=2E-6 Risk=8E-6 Risk=3E-4 Risk=1E-3 0.67 ....... ....... 1 of 5....... S
Acetoacet-o-toluidide (AAOT).... Risk=1E-5 Risk=6E-5 Risk=6E-4 Risk=4E-3 f.n. f.n. 0.31 4 of 5....... J(1), S
Acetoacetanilide (AAA).......... Risk=7E-6 Risk=3E-5 Risk=1E-4 Risk=6E-4 f.n. f.n. 0.14 5 of 5...... (J)(1), S
1,3-Dinitrobenzene.............. HQ <1 HQ <1 HQ=5 HQ=7 1.05 1.6 0.72 3 of 16...... J(3), I(3)
3,3'-Dimethyl- Pbenzidine....... Risk<1E-6 Risk<1E-6 Risk=3E-6 Risk=1E-5 1.9 2.4 1.3 2 of 16...... J(2), I(2)
Nitrobenzene.................... HQ <1 HQ <1 HQ=10 HQ=14 f.n. f.n. f.n. f.n.......... J
2,4-Dinitrophenol............... HQ <1 HQ <1 HQ=1 HQ=1 0.74 ....... ....... 1 of 16...... J
Combined Carcinogen Risk........ Risk=3E-5 Risk=1E-4 Risk=8E-3 Risk=6E-3
--------------------------------------------------------------------------------------------------------------------------------------------------------
*Risk estimates based on surrogate for 2-methoxyaniline.
**Risk estimates based on 2-aminotoluene.
***Exposure through ingestion of contaminated water.

f.n. Relevant data are not included at the present time due to business confidentialty concerns.

Notes:
All concentrations are in mg/kg.
J(#)--samples where estimated concentrations are below quantitation limits, ``(#)'' indicates number of samples that are ``J'' values.
I(#)--includes data supplied by industry, ``(#)'' indicates number of samples that are industry-supplied.
S--Toxicity estimated based on metabolic similarity to chemical analog.

Table II-3.--K162--Risk Values For Disposal in a Monofill (Other Than Drinking Contaminated Ground Water)
----------------------------------------------------------------------------------------------------------------
Vegetable ingestion Soil dermal contact Soil ingestion
Constituent -----------------------------------------------------------------------------------------
Central High end Central High end Central High end
----------------------------------------------------------------------------------------------------------------
1,3-Dinitrobenzene....
2-Aminoaniline........ R=4E-5 R=4E-5
2-Aminotoluene........ R=3E-6 R=2E-5
4-Aminotoluene........ R=1E-6 R=1E-6
2,4,6-Trichlorophenol. R=1E-6 R=2E-6
3,3'-Dichlorobenzidine R=2E-3 R=7E-3 R=7E-5 R=2E-4 R=9E-6 R=3E-5
3,3'-Dimethylbenzidine R=4E-3 R=5E-3 R=3E-5 R=3E-5 R=5E-6 R=6E-6
Acetoacet-o-anisidine. R=3E-5 R=3E-5
Acetoacet-o-toluidine. R=3E-4 R=5E-4
Acetoacetanilide...... R=ER-5 R=2E-4
Aniline............... R=1E-5 R=1E-5
Total Carcinogen Risk. R=6E-3 R>9E-3 R=1E-4 R=2E-4 R=1E-5 R=4E-5
----------------------------------------------------------------------------------------------------------------

Discussion

The volume reported by the industry in the 1991 RCRA Section 3007
Questionnaire data for wastewater treatment sludge from the manufacture
of azo pigments (K162) is not included at the present time due to
business confidentiality concerns. Over 99% of this wastestream
currently is disposed in Subtitle D municipal landfills. Therefore, the
Agency used disposal in a municipal landfill as the baseline management
practice. In addition, as explained under Section II.D, Description of
Health and Risk Assessments, the Agency evaluated on-site monofilling
as a plausible management scenario.
The projected risks of increased cancer or hazard quotient above
one for exposure to this waste are presented in Table II-2. The data
presented in this table represent 16 samples collected from 4 azo
pigment-manufacturing facilities. Eleven of the 16 samples were
collected and analyzed by industry, and were submitted to EPA for
evaluation. The 11 industry samples were analyzed using Gas
Chromatography/Mass Spectrometry (GC/MS), Method 8270B in EPA's ``Test
Methods for Evaluating Solid Waste, Physical/Chemical Methods'' (SW-
846, Third Edition) but were not analyzed using High Pressure Liquid
Chromatography/Thermospray/Mass Spectrometry (HPLC/TS/MS), Method 8321
in SW-846. EPA has reviewed the quality of these industry submitted
data and has found that these data meet the Agency's data quality
objectives and, therefore, qualify for inclusion in the waste
assessment. Inclusion of these industry data, however, does bias the
industry's characterization toward one facility (i.e., of 16 data
points, 11 were submitted by one facility, and 2 were collected by the
Agency at that same facility). The five EPA-collected samples,
representing four facilities, were analyzed using both methods, a
process which encompasses more analytes. Therefore, several analytes,
specifically acetoacetanilide (AAA), acetoacet-o-toluidide (AAOT), and
acetoacet-o-anisidide (AAOA), were detected in some or all of the EPA
samples, but were not analyzed in the industry samples.
The calculated risks from ingesting contaminated ground water
associated with disposing these sludges in on-site monofills are very
high. Three of the compounds that exceed risk levels of 1E-4 are common
raw materials used as coupling agents in the manufacture of azo
pigments: acetoacetanilide (AAA), acetoacet-o-anisidide (AAOA), and
acetoacet-o-toluidide (AAOT). These three compounds were expected to be
present in the waste, and consistently were found in the samples
collected by the Agency.
The three coupling compounds present in this waste, AAA, AAOA, and
AAOT, are predicted to pose very high risks via ground-water ingestion
when managed in an on-site monofill. As shown in Table II-2, the
calculated risks posed by these compounds range from 1E-3 to 6E-4.
These risks were calculated using metabolic product structural-activity
relationships (SAR) for these compounds. A detailed discussion of the
SAR for these compounds, and the estimation of toxicities for AAA,
AAOA, and AAOT is presented earlier in this preamble, under Section
II.C, Description of Health and Risk Assessments, and in the Health
Assessment Background Document for this proposed rule, which is located
in the RCRA Docket for this rulemaking (See addresses section).
These three compounds are high-volume couplers used in the
manufacture of azo pigments. Based on RCRA Section 3007 Questionnaire
data, AAA is the third highest-volume reactant in the pigment industry,
with over 8200 metric tons used in 1991. AAOT and AAOA also are used in
high volumes; their 1991 use volumes were 2600 and 850 Mtons,
respectively.
AAA, AAOT, and AAOA were found in 85% of the wastewater systems
where they are used. When detected in the wastewater system, the
compound was found either in the wastewater or in the sludge. Table II-
4 presents the number of wastewater systems where each of the three
coupling compounds were detected. Table II-4 also shows the number of
samples in which the three coupling compounds were detected relative to
the number in which the compounds were expected.

Table II-4
----------------------------------------------------------------------------------------------------------------
WWT System Wastewater Sludge
----------------------------------------------------------------------------------------------------------------
AAA............................... 5 of 5 systems.......... 4 of 4 samples.......... 5 of 5 samples.
AAOA.............................. 2 of 4 systems.......... 3 of 3 samples.......... 1 of 2 samples.
AAOT.............................. 4 of 4 systems.......... 1 of 4 samples.......... 4 of 4 samples.
----------------------------------------------------------------------------------------------------------------

Amides (e.g., AAA, AAOT, and AAOA) hydrolyze to form free acids and
amine salts under acidic conditions. Measurements of pH values of
process wastewaters at several pigment production facilities revealed
that these acidic conditions are encountered frequently. The hydrolysis
products for AAA, AAOT, and AAOA are aniline, 2-aminotoluene, and 2-
methoxyaniline, respectively. The unreacted amide raw materials and the
amines expected from hydrolysis of these amides both have been
identified in untreated wastewaters and wastewater biological treatment
sludges.
Two sets of coeluting compounds were observed from the analysis of
wastewater treatment sludge from the production of azo pigments. The
first set of coeluting compounds produced one data point, shown in
Table E1, for which the mass spectrum indicates the presence of 2-
methoxyaniline, along with the potential presence of 2- and 4-
aminoaniline (for a discussion of coeluting compounds and risk
assessments conducted on these compounds, please refer to the section
entitled ``Coeluting Compounds'' in Section II.D). 2-Methoxyaniline is
expected as a contaminant in the wastewater treatment sludge from the
facility that generated the sample because that facility manufactures
azo pigments using acetoacet-o-anisidide (AAOA) as a raw material, and,
as stated above, 2-methoxyaniline is an expected hydrolysis product of
AAOA. In addition, the facility from which this sample was collected
uses 2-aminoaniline as a reactant in the manufacture of azo dyes.
For this wastestream, the Agency conducted the risk assessment for
these coeluting compounds based on toxicity information for 2-
methoxyaniline because this contaminant is expected to be present from
azo pigment production. Since there currently is no HBL for 2-
methoxyaniline, the Agency based the risk assessment on the toxicity of
a surrogate compound. 2-Aminotoluene is a structural analog of 2-
methoxyaniline and is being used as a toxicity surrogate. The resulting
high-end individual cancer-risk level for 2-methoxyaniline was
calculated to be 2E-3 for the on-site monofill management scenario.
The second set of coeluting compounds consists of the two isomers
2- and 4-aminotoluene. The two isomers were detected in 3 out of 8
sludge samples from azo pigment manufacturing operations, and the
combined concentration of the two compounds was quantified. The
calculated high-end individual cancer-risk level, based on the toxicity
of 2-aminotoluene, is 3E-5 for the on-site monofill management
scenario.
In addition to the substantial calculated risks (i.e., exceeding
1E-4 for carcinogens) posed by raw materials used in azo pigment
manufacturing and their break-down products, four additional
contaminants were found in the wastestream at concentrations that are
projected to pose very high risks (HQs of 1 or greater for non-
carcinogens) through ingestion of contaminated ground water under
plausible management in an on-site monofill. 1,3-Dinitrobenzene,
nitrobenzene, and 2,4-dinitrophenol were found at concentrations that
resulted in calculated high-end HQs of 7, 9, and 1 respectively.
In addition to assessing the risks associated with the individual
constituents found in the waste, the Agency considers the combined risk
of constituents that co-exist in the wastestream. In the case of
wastewater treatment sludges generated from the manufacture of azo
pigments, all of the diazotization and coupling reactants and breakdown
products previously discussed in this section (i.e., AAA, AAOT, AAOA,
aniline, 2-aminotoluene, and 2-methoxyaniline) are assumed to co-exist
in the wastestream. The reactants are used in numerous large-volume
pigments which are manufactured on a frequent basis. Since this sludge
is a commingled wastestream representing production from the entire
plant, the constituents are likely to be present simultaneously in the
waste. Therefore, the combined risk of these individual constituents,
which is projected to be very high (i.e., 8E-3 at the high end), also
was considered in making this listing determination.
In addition to the very high risks posed by the plausible
management practice (a monofill), the calculated risks posed by the
current management practice (a municipal landfill) are also high. The
combined additive high-end risk for the reactants and breakdown
products previously discussed in this section (i.e., AAA, AAOT, AAOA,
aniline, 2-aminotoluene, and 2-methoxyaniline) is projected to be 1E-4
for the municipal landfill management practice. Therefore, EPA
concludes that even if the Agency considered current management and did
not consider plausible management, this wastestream would present a
substantial risk to human health and the environment, and should be
listed as hazardous.
Three additional constituents (i.e., aniline, 3,3'-
dimethylbenzidine, and 2-aminotoluene) were found in the wastewater
treatment sludge from azo pigment operations at concentrations that are
projected to pose risks within the Agency's risk range of concern
(i.e., 1E-4 to 1E-6 for carcinogens) using the on-site monofill
management scenario. Four constituents (i.e., AAOA, AAOT, AAA, and the
coeluting compounds 2-aminoaniline and 2-methoxyaniline) were found in
this waste at concentrations that pose risks between 1E-4 and 1E-6 for
carcinogens for the municipal landfill scenario. In addition, six
constituents pose risks within this range of potential concern through
indirect pathways.
Based on an analysis of the risks associated with both current and
plausible management practices, EPA is proposing to list wastewater
treatment sludge from the production of azo pigments as a hazardous
waste, designated as EPA Hazardous Waste Number K162.
For the reasons stated above, the Agency is proposing to add the
following constituents to Appendix VII to Part 261--Basis for Listing:
Aniline, 2-aminoaniline, 4-aminoaniline, 2-methoxyaniline, 2-
aminotoluene, 4-aminotoluene, acetoacet-o-anisidide, acetoacet-o-
toluidide, acetoacetanilide, 1,3-dinitrobenzene, 3,3'-
dimethylbenzidine, nitrobenzene, and 2,4-dinitrophenol.
In addition, acetoacet-o-anisidide, acetoacet-o-toluidide,
acetoacetanilide, 2-aminoaniline, 4-aminoaniline, 2- methoxyaniline,
and 1,3-dinitrobenzene are proposed to be added to Appendix VIII to
Part 261--Hazardous Constituents.
b. Wastewaters from the production of azo pigments (K163).

Summary

The Agency is proposing to list wastewaters from the production of
azo pigments as hazardous wastes. This waste meets the criteria set out
at 40 CFR 261.11(a)(3) for listing a waste as hazardous and is capable
of posing a significant present or potential hazard to human health or
the environment. Based on ingestion of contaminated ground water, EPA
calculated high-end individual risk levels for three carcinogens that
exceed 1E-4 for disposal in an unlined on-site surface impoundment, the
plausible management scenario. The calculated combined carcinogenic
risk for these constituents is 3E-4 from exposure to contaminated
ground water for the surface impoundment management scenario. To
further support this listing, four additional contaminants pose
individual risks between 1E-4 and 1E-6 for the surface impoundment
scenario.

Discussion

Data from the RCRA Section 3007 Questionnaire show that the 1991
volume reported by the industry for the wastewater stream from azo
pigment production is 9,914,662 metric tons, or approximately 7.2
million gallons per day. Over 75% of wastewaters from azo pigment
manufacturing currently are pretreated and discharged to a publicly
owned treatment works (POTW). Most of these wastewaters are treated in
equalization and neutralization tanks prior to discharge to a POTW. A
smaller percentage of these wastewaters is subjected to aerobic
biological treatment in tanks, with subsequent NPDES discharge to a
surface water.
As explained under Section II.D, Description of Health and Risk
Assessments, the risk assessment for these wastewaters was performed
using treatment in tanks as the current, or baseline, management
practice, and treatment in surface impoundments as a plausible
management scenario. The risks of increased cancer for exposure to this
waste are presented in Table II-5. The data presented in this table
represent six samples collected from four azo pigment manufacturing
facilities.

Table II-5.--Waste Characterization and Risk Estimates K163--Wastewaters From the Production of Azo Pigments
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline management Plausible management scenario Waste characterization
---------------------------------------------------------------------------------------------------------------------------------------
Constituents of Treat in tanks*** Treat in SI***
concern ---------------------------------------------------------------------- Avg. High
Central conc. conc. Low conc. # of pts Notes
tendency High end Central tendency High end
--------------------------------------------------------------------------------------------------------------------------------------------------------
2- & 4- All............ ............... Risk=5E-5 Risk=1E-4 f.n. 4.75 f.n. (J)........ 2 of 6....... J(1)
Aminoaniline/2-
Methoxyani-
line*.
2-, 3-, & 4- Constituents... ............... Risk=1E-5 Risk=2E-5 0.54 2.1 f.n. (J)........ 4 of 6....... J(3)
Aminoto-
luene**.
Aniline......... Dropped........ ............... Risk=2E-6 Risk=4E-6 f.n. f.n. f.n............. 4 of 5....... .............
Acetoacet-o- After.......... ............... Risk=5E-6 Risk=1E-5 f.n. 0.18 0.021(J)........ 3 of 6....... J(1), S
anisidide
(AAOA).
Acetoacet-o- Bounding....... ............... Risk=5E-5 Risk=1E-4 2.06 ....... ................ 1 of 6....... S
toluidide
(AAOT).
Acetoacetanilide Risk........... ............... Risk=4E-6 Risk=7E-6 f.n. f.n. f.n............. 4 of 6....... S
(AAA).
2,4- & 2,6- Assessment..... ............... Risk=5E-5 Risk=1E-4 f.n. ....... ................ f,n,......... .............
Dimethylaniline.
Combined ............... ............... Risk=2E-4 Risk=3E-4
Carcinogen Risk.
--------------------------------------------------------------------------------------------------------------------------------------------------------
*Risk estimates based on surrogate for 2-methoxyaniline.
**Risk estimates based on 2-aminotoluene.
***Exposure through ingestion of contaminated groundwater.

f.n. Relevant data are not included at the present time due to business confidentiality concerns.

Notes:
All concentrations are in mg/l.
J(#)--Samples where estimated concentrations are below quantitation limits, `(#)' indicates number of samples that are `J' values.
S--Toxicity estimated based on metabolic similarity to chemical analog.

The calculated risks associated with managing these wastewaters in
surface impoundments are very high. Three constituents are considered
to pose a substantial potential hazard to human health and the
environment (i.e., risks exceed 1E-4). Calculated risks for each of
these three compounds are 1E-4.
Three of the constituents that have been projected to pose a risk
greater than 1E-6, namely, acetoacetanilide (AAA), acetoacet-o-
toluidide (AAOT), and acetoacet-o-anisidide (AAOA), are high-volume
coupling reactants used in the manufacture of azo pigments. As
explained above for K162, these constituents are dominant raw materials
in the azo pigment manufacturing industry and generally are present in
the wastewater treatment systems at these sites. As shown in Table II-
5, the risks calculated by these compounds range from 1E-4 to 1E-6. As
stated for K162, these risks were calculated using metabolic product
structural-activity relationships (SAR) for these compounds, an
approach which is discussed in detail in Section II.D of this preamble,
and in the Listing Background Document for this proposed rule, which is
located in the RCRA Docket for this rulemaking (See ADDRESSES section).
Table II-4, presented earlier, shows that AAA and AAOA were
detected in all of the wastewater samples collected from facilities
that use these reactants. AAOT was found only in one of four wastewater
samples, but it was found in all four of the sludge samples collected
from facilities using the compound. The Agency believes that the latter
compound generally is present in the wastewater treatment system at
facilities that use AAOT as a raw material but that it may be
preferentially partitioning to the sludge.
In addition to the high risks calculated by the three reactants,
AAA, AAOA, and AAOT, the hydrolysis products of these compounds,
aniline, 2-aminotoluene, and 2-methoxyaniline, also were detected in
the waste at concentrations that pose significant risk (i.e., risks
ranging from 1E-4 to 4E-6). Discussions addressing hydrolysis pathways
and conditions for these compounds, and the issue of coeluting
compounds associated with the hydrolysis products, were presented
earlier in this preamble (see discussion of K162, and Section II.D).
In addition to the primary raw materials and breakdown products
presented above, the combined 2,4- and 2,6-isomers of dimethylaniline,
which also are suspected raw material breakdown products, were detected
in this waste at concentrations that pose a very high risk (i.e., a
risk of 1E-4).
Along with risks associated with the individual constituents found
in the waste, the Agency considers the combined risks of constituents
that co-exist in the wastestream. In the case of wastewaters generated
from the manufacture of azo pigments, all of the reactants and
breakdown products previously discussed in this section (i.e., AAA,
AAOT, AAOA, aniline, 2-aminotoluene, and 2-methoxyaniline) are assumed
to co-exist in the wastestream. The reactants are used in producing
numerous large-volume pigments that are manufactured on a frequent
basis. Since this wastewater stream represents several commingled
wastestreams from throughout the plant, the constituents are likely to
be present simultaneously in the waste. Therefore, the combined risks
of these individual constituents, which are projected to be very high
under the surface impoundment mismanagment scenario (i.e., 3E-4 at the
high end), also were considered in making this listing determination.
Based on the calculated risks associated with the plausible
management practice for this waste (treatment in surface impoundments),
EPA is proposing to list wastewaters from the production of azo
pigments as a hazardous waste, designated EPA Hazardous Waste Number
K163. However, the Agency recognizes that if wastewater treatment
sludges from the production of azo pigments (K162) are listed as
proposed, the available options for wastewater management may change
and the surface impoundment scenario may not be plausible for the
following reason: wastewaters that are managed in an impoundment will
generate sludges through precipitation. In the event that K162 sludges
were listed and the wastewaters were not, the sludges generated in a
Subtitle D wastewater impoundment would be hazardous wastes and the
surface impoundment would become subject to RCRA Subtitle C regulation.
The Agency is requesting comment on whether the use of Subtitle D
surface impoundments to manage wastewaters would be a plausible
management scenario if the wastewaters were not listed but the
wastewater treatment sludges were listed as hazardous wastes. The
Agency also is requesting comment on the need to list K163 wastewaters,
given that the plausibility of the management scenario on which the
risk assessment was based may be affected by the final outcome of the
K162 sludge listing.
For the reasons stated above, EPA proposes to add the following
constituents to Appendix VII to Part 261--Basis for Listing: Aniline,
2-aminoaniline, 4-aminoaniline, 2-methoxyaniline, 2-aminotoluene, 3-
aminotoluene, 4-aminotoluene, acetoacet-o-anisidide, acetoacet-o-
toluidide, acetoacetanilide, 2,4-dimethylaniline, and 2,6-
dimethylaniline.
In addition, 2-aminoaniline, 4-aminoaniline, 2-methoxyaniline, 3-
aminotoluene, acetoacet-o-anisidide, acetoacet-o-toluidide,
acetoacetanilide, 2,4-dimethylaniline, and 2,6-dimethylaniline are
proposed to be added to Appendix VIII to Part 261--Hazardous
Constituents.
2. Wastes from the production of azo dyes.
a. Wastewater treatment sludge from the production of azo dyes,
excluding FD&C colorants (K164).
Summary
EPA is proposing to list wastewater treatment sludge from the
production of azo dyes, excluding FD&C colorants, as a hazardous waste.
This wastestream meets the criteria set out at 40 CFR 261.11(a)(3) for
listing a waste as hazardous and is capable of posing a substantial
present or potential risk to human health or the environment. Based on
ingestion of contaminated ground water, EPA calculated high-end
individual cancer risk levels for five constituents which exceed 1E-4
for carcinogens and have HQs of 1 or greater for non-carcinogens for
the plausible management practice, an on-site monofill. Four additional
contaminants further support the listing by posing individual risks
between 1E-4 and 1E-6. Risks between 1E-4 and 1E-6 also were identified
for six contaminants from exposure to these constituents through other
exposure pathways.
Discussion
The majority of wastewater treatment sludge from the production of
azo dyes is biological treatment sludge. The information on volume and
the percentage of this waste volume disposed of at Subtitle D municipal
landfills, as reported in the 1992 RCRA Section 3007 Questionnaire, is
not included at the present time due to business confidentiality
concerns.

Table II-6.--Waste Characterization and Risk Estimates, K154--Wastewater Treatment Sludge From the Production of Azo Dyes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline management# Plausible management scenario Waste characterization
-----------------------------------------------------------------------------------------------------------------------------------
Constituents of Municipal landfill**** On-site monofill**** Vegetable ingestion
concern ------------------------------------------------------------------------ Avg. High Low
Central Central Central conc. conc. conc. # of pts Notes
tend. High end tend. High end tend. High end
--------------------------------------------------------------------------------------------------------------------------------------------------------

2- R=4E-6 R=2E-5 R=2E-4 R=5E-4 R=4E-5 R=4E-5 7.17 ....... ....... 1 of 7....... J
&
4
A
m
i
n
o
a
n
i
l
i
n
e
/
2-

M
e
t
h
o
x
y
a
n
i-

l
i
n
e
*.
Aniline............. R<1E-6 R<1E-6 R=2E-6 R=1E-5 R=2E-6 R=2E-6 f.n. f.n. 14 f.n.......... ................
Diphenylamine/N- R<1E-6 R<1E-6 R<1E-6 R=2E-6 .......... .......... f.n. f.n. f.n. f.n.......... J
Nitrosodi-
phenylamine**.
3,3'- R<1E-6 R<1E-6 R=4E-6 R=2E-5 R=3E-6 R=3E-6 f.n. f.n. f.n. f.n.......... ................
Dimethoxybenzidine.
4-Methylphenol...... R<1E-6 R<1E-6 HQ = 2 HQ = 3 .......... .......... 9.5 ....... ....... 1 of 7....... ................
1,3-Dinitrobenzene.. HQ < 1 HQ < 1 HQ = 34 HQ = 45 .......... .......... 1.05 1.6 0.72 3 of 8....... J
2-Methoxy-5- R<1E-6 R<1E-6 R<1E-6 R=2E-6 R=5E-6 R=5E-6 0.92 ....... ....... 1 of 10...... J(3),I(3)
nitroaniline.
2,4-Dinitrophenol... HQ < 1 HQ < 1 HQ = 1 HQ = 2 .......... .......... 0.74 ....... ....... 1 of 18...... J,I
2- & 4-Aminoto- R<1E-6 R=1E-6 R=3E-5 R=1E-4 R=1E-5 R=2E-5 1.3 1.5 1.2 3 of 11...... J(5),I(9)
luene***.
Combined R=4E-6 R=2E-5 R=2E-4 R=7E-4
Carcinogenic Risk.
--------------------------------------------------------------------------------------------------------------------------------------------------------
# Underestimates risks due to disposal in on-site monofill, not included in estimate.
* Risk numbers based on 2-aminoaniline.
** Risk numbers based on N-nitrosodiphenylamine.
*** Risk numbers based on 2-aminotoluene.
**** Exposure through ingestion of ground water.

f.n. Relevant data are not included at the present time due to business confidentiality concerns.

Notes:
All concentrations are in mg/kg.
J(#)--Samples where estimated concentrations are below quantitation limits, `(#)' indicates number of samples that are `J' values.
I(#)--Includes data supplied by industry, `(#)' indicates number of samples that are industry-supplied.
S--Toxicity estimated based on metabolic similarity to chemical analog.

As discussed earlier under Section II.D, Description of Health and
Risk Assessments, the Agency conducted the risk assessment on these
wastestreams using both a current, or baseline management scenario, and
a plausible management scenario. Information relating to this
discussion is not included at the present time due to business
confidentiality concerns.
Therefore, the Agency conducted the risk assessment on two current
management scenarios, a municipal landfill, and a monofill, with the
monofill representing the plausible management practice.
The risk projections associated with this wastestream are presented
in Table II-6. The data presented in this table represent 18 samples
collected from four azo dye manufacturing facilities. Eleven of the 18
samples were collected and analyzed by industry, and were submitted to
EPA for evaluation.
The risks associated with disposing these sludges in monofills are
projected to be very high. Five constituents found in the waste are
predicted to pose individual high-end cancer-risk levels equal to or
exceeding 1E-4 or HQs equal to or exceeding 1 for non-carcinogens,
through ingestion of contaminated ground water or vegetables. The five
constituents pose carcinogenic risks ranging from 1E-4 to 5E-4 and non-
carcinogenic hazards from 2 to 45 times above the RfDs for the monofill
management scenario.
There are two cases of coeluting constituents for this wastestream.
As shown in Table II-6, there is one data point for which the mass
spectrum indicates the presence of 2- methoxyaniline, along with the
potential presence of 2- and 4- aminoaniline. As discussed in Section
II.D, EPA based the risk assessment for this set of coeluting compounds
on 2-aminoaniline. The calculated high-end individual cancer-risk level
for 2- aminoaniline is 5E-4 for the monofill management scenario.
The second set of coeluting compounds consists of the three isomers
2-, 3-, and 4-aminotoluene. The presence of the three isomers was
confirmed in four out of six wastewater samples collected from azo dye
manufacturing operations, and the combined concentration of the three
compounds was quantified. The calculated high-end individual cancer-
risk level, based on the toxicity of 2-aminotoluene, is 1E-4 for the
monofill management scenario (See Section II.D of this preamble,
Coeluting Compounds, for more details on the Agency's approach to risk
assessment for coeluting compounds).
In addition to the two sets of coeluting compounds used as raw
materials in azo dye manufacturing, three compounds, 1,3-
dinitrobenzene, 4-methylphenol, and 2,4-dinitrophenol were found at
concentrations that are projected to pose a substantial risk to human
health and the environment. The risks presented by these compounds are
calculated to have high-end HQs of 45, 3, and 2, respectively.
Aniline is a high-volume dye reactant present in the wastewater
treatment sludge at multiple facilities, according to RCRA Section 3007
questionnaire data. Aniline is the fourth highest-volume reactant used
in the dye industry, according to data provided in the 1991 RCRA
Section 3007 Questionnaires, with a 1991 use volume of 4860 metric
tons. Based on the aniline concentrations found in the waste, the
Agency has calculated a high-end individual cancer-risk level for this
constituent at 1E-5.
Aniline was found in over 70% of the samples of wastewater
treatment sludge from azo dye production. However, 11 of the 13 aniline
data points, which were all from one facility, were dropped prior to
the risk assessment because the facility reported that aniline found in
the wastewater treatment sludges is associated with non-dye operations.
This facility consumes larger volumes of aniline in their non-dye
operations than in the manufacture of azo dyes. It is likely that
aniline from dye operations contributed to the presence of the
constituent in the waste; however, the Agency could not determine the
extent of this contribution.
In studying the wastewater treatment systems from azo dye
manufacturing operations as a whole, the Agency found aniline to be
present in all systems from which samples were collected. In addition,
aniline was consistently present in the wastewaters for all samples
collected. Furthermore, even though aniline would be expected to
biodegrade in the wastewater treatment system, aniline was present in 2
out of 5 samples from the wastewater treatment sludge. Because the
wastewater treatment sludge presents a complex matrix for chemical
analysis, the detection limits obtained for the wastewater treatment
sludges were high. Therefore, the Agency believes that, given the
consistent presence of aniline in the wastewater, and the detection of
aniline in 2 out of 5 sludge samples (with 11 data points dropped for
the reasons stated earlier), aniline typically is present in wastewater
treatment sludges from azo dye manufacturing operations. Based on the
aniline concentrations found in the two data points that remain after
11 data points were dropped, the Agency has determined that the risk
posed by aniline in this wastestream is significant.
An additional high-volume raw material used in the manufacture of
azo dyes, 3,3'-dimethoxybenzidine, was found to be present in the
wastewater treatment sludge from azo dye operations at concentrations
that result in calculated high-end individual cancer-risk level of 2E-
5. Based on data from the 1991 RCRA Section 3007 Questionnaire, 1719
metric tons of 3,3'-dimethyoxybenzidine were used in the manufacture of
azo dyes in 1991.
In addition to the risks posed by the individual hazardous
constituents found in the waste, some of the contaminants are co-
occurring in this wastestream. The Agency found that sludge samples
collected from each of the four azo dye manufacturing facilities
generally contain one or more toxic raw materials simultaneously.
Therefore, some individual carcinogens are co-occurring in the waste
and the calculated risks are assumed to be additive. Given the waste
characterization and risk assessment results, along with toxicity
information on other raw materials used in the production of azo dyes
(i.e., aromatic amines), the Agency believes that wastewater treatment
sludges from azo dye manufacturing typically contain one or more toxic
raw materials at concentrations that pose a significant risk.
In addition to the azo dye raw materials that were found in the
wastestream at concentrations that pose a high risk, two additional
constituents, 2-methoxy-5-nitroaniline, and the two coeluting compounds
diphenylamine and N-nitrosodiphenylamine, were found in the wastewater
treatment sludge from azo dye operations at concentrations that pose
carcinogenic risks above 1E-6 (See Section II.D for treatment of
coeluting compounds).
The results from the assessment of exposure pathways other than
drinking contaminated ground water resulting from management in an on-
site monofill also are presented in Table II-6. Calculated high-end
individual cancer-risk levels between 1E-4 and 1E-6 were identified for
six contaminants through indirect exposure pathways (contaminated
vegetable ingestion) if airborne dusts are not controlled.
In addition to the risks posed by the monofill management practice,
the calculated risk posed by municipal landfill disposal also is within
EPA's range of potential concern, 1E-6 to 1E-4, for two sets of
coeluting compounds, 2- and 4-aminoaniline/2-methoxyaniline, and 2- and
4-aminotoluene. The Agency also considered the risks posed by these
contaminants for a municipal landfill when making the listing decision.
Based on an analysis of the risks associated with the current
management practices, a monofill and municipal landfill, EPA is
proposing to list as hazardous wastewater treatment sludge from the
production of azo dyes, excluding FD&C colorants, designated EPA
Hazardous Waste Number K164.
For the reasons stated above, the Agency is proposing to add the
following constituents to Appendix VII to Part 261--Basis for Listing:
2-aminoaniline, 4-aminoaniline, 2-methoxyaniline, aniline,
diphenylamine, N-nitrosodiphenylamine, 3,3'-dimethoxybenzidine, 4-
methylphenol, 1,3-dinitrobenzene, 2-methoxy-5-nitroaniline, 2,4-
dinitrophenol, 2-aminotoluene, and 4-aminotoluene.
In addition, 2-aminoaniline, 4-aminoaniline, 2-methoxyaniline, N-
nitrosodiphenylamine, 4-methylphenol, 1,3-dinitrobenzene, and 2-
methoxy-5-nitroaniline are proposed to be added to Appendix VIII to
Part 261--Hazardous Constituents.
b. Wastewaters from the production of azo dyes, excluding FD&C
colorants (K165).
Summary
The Agency is proposing to list wastewaters from the production of
azo dyes, excluding FD&C colorants, as hazardous. This wastestream
meets the criteria set out at 40 CFR 261.11(a)(3) for listing a waste
as hazardous and is capable of posing a substantial present or
potential hazard to human health or the environment. Based on ingestion
of contaminated ground water, EPA calculated a high-end individual risk
level of 1E-4 for one hazardous constituent for the plausible
management scenario, treatment in an unlined surface impoundment. Two
additional constituents are estimated to pose risks between 1E-4 and
1E-6 for the surface impoundment scenario.
Discussion
Based on response data from the 1991 RCRA Section 3007
Questionnaire, the volume reported by the industry for wastewaters from
azo dye production, excluding FD&C colorants, was 6,295,779 metric tons
per year, or 4.6 million gallons per day. Approximately 58% of
wastewaters from azo dye production, excluding FD&C colorants currently
are pretreated and discharged to a POTW. Over 40% of these wastewaters
are treated in aerobic biological tank systems, with subsequent NPDES
discharge to a surface water. Approximately 5% of the wastewaters from
azo dye operations excluding FD&C colorants are treated in biological
treatment systems that use surface impoundments.
As discussed earlier under Section II.D, Description of Health and
Risk Assessments, the risk assessment for these wastewaters was
performed using treatment in tanks as the current, or baseline,
management practice, and treatment in surface impoundments as a
plausible management scenario. For this waste, however, the worst-case
management scenario, treatment in a surface impoundment, is also one of
the current management practices. The calculated risks of increased
cancer or hazard quotient above one for exposure to this waste are
presented in Table II-7. The data presented in this table represent
seven samples collected from five azo dye-manufacturing facilities.

Table II-7--Waste Characterization and Risk Estimates K165--Wastewaters From the Production of Azo Dyes, Excluding FD&C Colorants
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline management Plausible Management Waste Characterization
---------------------------------------------------------------------------------------------------------------------------------------
Constituents of Treat in tanks*** Treat in SI***
concern ---------------------------------------------------------------------- Avg. High
Central conc. conc. Low conc. # of pts Notes
tendency High end Central tendency High end
--------------------------------------------------------------------------------------------------------------------------------------------------------
2- & 4- Insignificant ............... Risk=6E-6 Risk=1E-5 f.n. 4.75 f.n............. 3 of 8....... .............
Aminoaniline/2- risk for any
Methoxyani- constituent.
line*.
2-, 3-, & 4- ............... ............... Risk=6E-5 Risk=1E-4 f.n. f.n. 0.048 (J)....... 6 of 8....... J(2)
Aminoto-
luene**.
Aniline......... ............... ............... Risk=<1E-6 Risk=2E-6 f.n. f.n. 0.063........... 5 of 5....... .............
Combined ............... ............... Risk=6E-5 Risk=1E-4
Carcinogenic
Risk.
--------------------------------------------------------------------------------------------------------------------------------------------------------
*Risk estimates based on 2-aminoaniline.
**Risk estimates based on 2-aminotoluene.
***Exposure through ingestion of contaminated ground water.

f.n. Relevant data are not included at the present time due to business confidentiality concerns.

The risk associated with the wastewaters in tanks is estimated to
be below levels of concern. However, the risks associated with managing
these wastewaters in surface impoundments are calculated to be high.
One constituent found in the waste is considered capable of posing a
substantial present or potential risk to human health or the
environment (i.e., risks are 1E-4 or higher for carcinogens, or 1 or
higher HQs for non-carcinogens). The constituent poses a risk 1E-4.
As was the case with wastewater treatment sludge from the
production of azo dyes, excluding FD&C colorants, the wastewaters were
found to contain high concentrations of aniline, a high-volume dye
reactant that poses an unacceptable risk at such levels. In fact,
aniline was present in each of the seven wastewater samples from azo
dye production. However, two of the seven aniline data points, which
were both from one facility, were dropped prior to the risk assessment
because the facility reported that aniline found in the wastewater is
associated with non-dye operations. This facility consumes larger
volumes of aniline in their non-dye operations than in the manufacture
of azo dyes. It is likely that aniline from dye operations contributed
to the presence of the constituent in the waste; however, the Agency
could not determine the extent of this contribution.
Based on the aniline concentrations represented by the five
remaining data points, the Agency has determined that the risks posed
by aniline in this wastestream are 2E-6).
The presence of three coeluting isomers, 2-, 3-, and 4-
aminotoluene, was confirmed in four out of six wastewater samples
collected from azo dye manufacturing operations, and the combined
concentration of the three compounds was quantified (refer to earlier
discussion under Section II.D.2, Coeluting Compounds, for a discussion
on the coelution of 2-, 3-, and 4-aminotoluene). The calculated high-
end individual cancer-risk level, based on the toxicity of 2-
aminotoluene, is 1E-4 for the surface impoundment management scenario.
The second set of coeluting compounds consists of 2- and 4-
aminoaniline, and 2-methoxyaniline. EPA based the risk assessment for
this set of coeluting compounds on 2-aminoaniline, as discussed in
Section II.D.2. The resulting calculated high- end individual cancer-
risk level is 1E-5 for the surface impoundment management scenario.
Based on the risks associated with the plausible management
practice for this waste, EPA is proposing to list wastewaters from the
production of azo dyes, excluding FD&C colorants, as a hazardous waste,
designated EPA Hazardous Waste Number K165. However, the Agency
recognizes that if wastewater treatment sludges from the production of
azo dyes (K164) are listed as proposed, the available options for
wastewater management may change and surface impoundments may not be
used. Wastewaters that are managed in an impoundment will generate
sludges through precipitation. In the event that K164 sludges were
listed and the wastewaters were not, the sludges generated in a
Subtitle D wastewater impoundment would be hazardous wastes and the
surface impoundment would become subject to RCRA Subtitle C regulation.
The Agency is requesting comment on whether it would be plausible to
use a Subtitle D surface impoundment to manage wastewaters if the
wastewaters were not listed and the wastewater treatment sludges were
listed as hazardous wastes. The Agency also is requesting comment on
the need to list K165 wastewaters, given that the plausibility of the
worst-case management scenario on which the risk assessment was based
may be affected by the K164 sludge listing.
For the reasons stated above, EPA proposes to add the following
constituents to Appendix VII to Part 261--Basis for Listing: 2-
aminoaniline, 2-methoxyaniline, 2-aminotoluene, 3- aminotoluene, 4-
aminotoluene, and aniline.
In addition, 2-aminoaniline, 4-aminoaniline, 2-methoxyaniline and
3-aminotoluene are proposed to be added to Appendix VIII to Part 261--
Hazardous Constituents.
3. Wastes from the production of triarylmethane dyes and pigments
(excluding triarylmethane pigments using aniline as a feedstock).
a. Wastewater treatment sludge from the production of
triarylmethane dyes and pigments (excluding triarylmethane pigments
using aniline as a feedstock).
Summary
EPA is proposing to defer the decision on whether to list
wastewater treatment sludges from the production of triarylmethane dyes
and pigments (excluding triarylmethane pigments using aniline as a
feedstock) due to insufficient waste characterization data. The Agency
is planning to collect additional information on this wastestream. EPA
then will publish a supplemental notice with a proposed determination
on whether to list this waste.
Discussion
This waste is generated from the treatment of wastewaters from
triarylmethane dye and pigment manufacturing. These wastewaters often
are commingled with wastewaters from the manufacture of other dyes and
pigments. As a result, the wastewater treatment sludges typically are
managed also as a commingled wastestream from the production of
triarylmethane and any other dyes or pigments manufactured at the site.
Based on the RCRA Section 3007 Questionnaire data, the 1991 volume
reported by the industry for this wastestream is 1,404 metric tons.
Wastewater treatment sludge from the production of triarylmethane
dyes and pigments is generated at only five facilities. The Agency's
sampling program, which was conducted in support of this listing
determination, included wastewater treatment sludge from one of the
five facilities generating this waste. However, the facility was not
manufacturing triarylmethane dyes or pigments during the time of the
sampling activities. Therefore, the resulting absence of constituents
attributable to the triarylmethane operations was not unexpected.
In conclusion, based on insufficient characterization data, the
Agency proposes to defer a listing decision on wastewater treatment
sludges from the production of triarylmethane dyes and pigments
(excluding triarylmethane pigments using aniline as a feedstock). The
Agency is proposing to conduct additional sampling on this wastestream
and will publish a supplemental notice with a proposed listing
determination.
b. Wastewaters from the production of triarylmethane dyes and
pigments (excluding triarylmethane pigments using aniline as a
feedstock).
Summary
EPA is proposing not to list wastewaters from the production of
triarylmethane dyes and pigments (excluding triarylmethane pigments
using aniline as a feedstock) because the constituents in this waste
were observed at concentrations that present low risk levels (i.e.,
calculated at less than 1E-6 for carcinogens and lower than 1 HQ for
non-carcinogens) through ingestion of contaminated ground water, and no
other hazardous constituents attributed to triarylmethane dye or
pigment production were detected.
Discussion
Volume information reported by the industry in the 1992 RCRA
Section 3007 Questionnaire for the wastewater stream from
triarylmethane dye and pigment production is not included at the
present time due to business confidentiality concerns. Wastewaters from
the production of triarylmethane dyes and pigments (excluding
triarylmethane pigments using aniline as a feedstock) often are
commingled with wastewaters from the manufacture of azos and other dyes
and pigments.

Table II-8.--Waste Characterization and Risk Estimates Wastewaters From the Production of Triarylmethane Dyes and Pigments (Excluding Triarylmethane
Pigments Using Aniline as a Feedstock)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline management Plausible management Waste characterization
------------------------------------------------------------------------------------------------------------------------
Treat in Tanks* Treat in SI*
Constituents of concern ------------------------------------------------------------ Avg. High
Central Central conc. conc. Low conc. # of pts Notes
tendency High end tendency High end
--------------------------------------------------------------------------------------------------------------------------------------------------------
f.n............................ No HBL....... ............. No HBL....... ............. f.n. ......... ......... 1 of 3......
4-Nitroaniline................. No HBL....... ............. No HBL....... ............. 0.016 ......... ......... 1 of 3...... J
f.n.
(3)All remaining constituents
were dropped following
bounding on baseline
management
4-Methylphenol
f.n.
f.n.
N,N'-Dimethylaniline
f.n.
--------------------------------------------------------------------------------------------------------------------------------------------------------
AA* Exposure through ingestion of contaminated ground water.

f.n. Relevant data are not included at the present time due to business confidentiality concerns.

Notes:
All concentrations are in mg/l.
J(#)--samples where estimated concentrations are below quantitation limits, `(#)' indicates number of samples that are `J' values.

Information on the percentage of these wastewaters currently
pretreated and discharged to a POTW, and on the percentage treated in a
biological treatment system and discharged to a surface water under the
NPDES system is not included at the present time due to business
confidentiality concerns. As discussed earlier under Section II.D,
Description of Health and Risk Assessments, the risk assessment for
these wastewaters was performed using treatment in tanks and surface
impoundments as the baseline and plausible management practices,
respectively.
The Agency believes that the three wastewater samples collected
from the manufacture of triarylmethane dyes and pigments are
representative of the industry, in part, because wastewater samples
were collected from the two largest triarylmethane dye producers in the
country. Furthermore, the chemical analyses conducted on this waste
encompassed the most important raw materials used in the manufacture of
triarylmethane dyes and pigments, and these compounds were not detected
at concentrations that pose a significant risk. For example, N,N-
dimethylaniline is a large volume raw material used in the manufacture
of triarylmethane dyes and pigment, and was analyzed using the Gas
Chromatography/Mass Spectrophotometry analytical method. In addition to
the GC/MS analysis, specific analyses were conducted in order to look
for two additional toxic raw materials for triarylmethane dyes and
pigments; chloranil and another raw material that cannot be identified
due to business confidentiality concerns. As shown in Table II-8, N,N-
dimethylaniline and the other raw material that cannot be identified
were not found in these wastewaters at concentrations that pose a
significant risk, and chloranil was not detected at all in the
wastewaters.
Table II-8 presents eight constituents, obtained from three
wastewater samples which were collected at three out of 14 facilities
that manufacture triarylmethane dyes or pigments. These eight compounds
are the constituents that were found to be attributable to the
triarylmethane processes, and six of the eight compounds were dropped
following the risk assessment screening (see the Listing and Risk
Assessment for Dye and Pigment Waste Listing Determination Background
Documents for this proposed rule, located in the RCRA Docket for this
rulemaking (see ADDRESSES section) for the process used in identifying
attributable constituents and for the process used for dropping
compounds after risk screening, respectively). Because these compounds
are not expected to bioaccumulate, the maximum measured concentrations
of those constituents with HBLs in this wastestream were compared to
their HBLs, and the ratio of concentrations to HBL values was less than
1, indicating that the concentrations of these compounds in the waste
are not expected to pose a risk to human health or the environment. The
two remaining constituents, 4-nitroaniline and a constituent that
cannot be identified at the present time due to confidentiality
concerns, were detected at low concentrations and do not have HBLs
needed to conduct a risk assessment. The risks posed by these two
constituents, however, were assessed using surrogate compounds. Neither
of the compounds are expected to be potential carcinogens. Furthermore,
the Agency selected surrogate compounds that are structurally similar
to the compounds detected in the waste, and are estimated, by means of
structural activity relationships (SARs), to be more toxic than the
subject compounds. Nitrobenzene was selected as a surrogate for 4-
nitroaniline. Surrogate information on the second constituent cannot be
included at the present time due to business confidentiality concerns.
The ratios of concentration to HBL (HQ) determined by this analysis
were also less than 1, indicating that, if the contaminant
concentrations found in the waste were actually present in drinking
water, the risks posed by ingesting the drinking water would be
insignificant. More detailed discussions on the risk assessment
screening and surrogate compounds are presented in the Dye and Pigment
Listing Support Health Effects Background Document, which is located in
the RCRA Docket for this rulemaking (see ADDRESSES section).
In conclusion, because the constituents in this waste were observed
at concentrations that present low risk levels, and no other hazardous
constituents attributed to triarylmethane dye or pigment production
were detected, the Agency is proposing not to list wastewaters from the
manufacture of triarylmethane dyes and pigments as hazardous.
4.Wastes from the production of triarylmethane pigments using
aniline as a feedstock.
Triarylmethane pigments using aniline as a feedstock currently are
produced at two domestic facilities. These facilities each produce a
single product which is manufactured throughout the year using aniline
as the major feedstock. The two processes are markedly different from
other dye and pigment processes in the industry. Most dye and pigment
processes manufacture numerous products on a batch basis, using
different raw materials for each product. The wastes generated from
typical dye manufacturing plants vary in composition over time due to
the constant changes in raw materials. In contrast, triarylmethane
pigments using aniline as a feedstock are generated at facilities that
are dedicated to the manufacture of one product continuously throughout
the year, and use only two raw materials, aniline and formaldehyde, at
the site. In addition, aniline is used in excess in the process. These
differences have a significant impact on the compositions of the waste.
Such wastes were expected, and found, to contain high concentrations of
aniline. The listing Background Document, found in the RCRA docket (see
ADDRESSES section) for this proposed rulemaking, contains details on
the process for manufacturing triarylmethane (TAM) pigments using
aniline as a feedstock.
a. Wastewater treatment sludge from the production of
triarylmethane pigments using aniline as a feedstock.
Summary
The Agency is proposing not to list as hazardous wastewater
treatment sludges from the production of triarylmethane pigments using
aniline as a feedstock. If this wastestream were managed by disposal in
a municipal landfill (the plausible management scenario used for other
wastewater treatment sludges), it would meet the criteria set out at 40
CFR 261.11(a)(3) for listing a waste as hazardous and would be capable
of posing a substantial present or potential hazard to human health or
the environment. However, as discussed in Section II.D, Description of
Health and Risk Assessments, the Agency has determined that management
in a municipal landfill is not plausible for this wastestream. Despite
this determination, for comparison purposes the Agency calculated the
risks associated with disposal in a municipal landfill and with diposal
in an on-site boiler. If, based on comments, the Agency determines that
it is not reasonable to use fuel blending as the plausible management
scenario, the Agency probably would determine that plausible management
is disposal in a municipal landfill for the ground-water pathway, and
is disposal in an on-site boiler for the air pathway. Disposal in an
on-site monofill, which was established as the plausible management
scenario for other wastewater treatment sludges (i.e., K162 and K164),
is not a practical option for this wastestream due to its low volume
relative to the capacity of a monofill, and so is not feasible
economically.
Based on ingestion of contaminated ground water due to releases
from a municipal landfill, EPA calculated high-end individual cancer-
risk levels of 1E-4 and 8E-5 for the constituents benzidine and
aniline, respectively. The coeluting compounds 1,2-diphenylhydrazine
and azobenzene are calculated to pose risks between 1E-6 and 1E-5.
Therefore, the combined carcinogenic risk for multiple co-existing
constituents in this wastestream would be 2E-4, assuming disposal in a
landfill. However, the risks associated with the current and plausible
management practice, blending with non-hazardous fuel, are
insignificant for any constituent. Thus, the Agency is proposing not to
list it as hazardous.
Discussion
Wastewater treatment sludge from the production of triarylmethane
pigments using aniline as a feedstock currently is generated at only
one facility. This waste is generated from a filter press that is used
as part of the wastewater pretreatment system. The waste is generated
at a rate of approximately 18 metric tons per year.
EPA has summarized the risk projections associated with this sludge
in Table II-9. The data presented in this table represent one sample
from one facility. Unlike earlier wastestreams, health benchmarks exist
for all the contaminants detected in this wastestream (with the
exception of one coeluting compound, which is discussed later in this
section). Additional compounds which do have health benchmarks,
however, have been identified in these wastes, but were dropped from
further consideration following the risk screening. The complete list
of compounds found in this and other wastestreams is presented in the
Listing Background Document for this proposed rule, which is located in
the RCRA Docket for this rulemaking (see ADDRESSES section).
Details on the risk assessment are provided in Section II.D of this
preamble, Description of Health and Risk Assessments, and in the
Listing Background Document for this proposed rule, located in the RCRA
Docket for this rulemaking (see ADDRESSES section).

Table II-9.--Waste Characterization and Risk Estimates Wastewater Treatment Sludge From the Production of Triarylmethane Pigments Using Aniline as a
Feedstock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Plausible management Other management Waste characterization
---------------------------------------------------------------------------------------------------------------------------------------
Constituents of Off-site non-haz fuel blending** On-site boiler** Municipal landfill***
concern ------------------------------------------------------------------------------------ Avg. High Low
Central Central conc. conc. conc. # of pts Notes
Central tendency High end tendency High end tendency High end
--------------------------------------------------------------------------------------------------------------------------------------------------------
1,2-Diphenyl- Insignificant ................ Risk <1E-6 Risk <1E-6 Risk =5E-6 Risk =2E-5 370(J) 1 of 1.... J
hydrazine/ risk for any
Azoben- zene*. constituent.
Aniline......... ................ ................ HQ<1 HQ<1 Risk =2E-5 Risk =8E-5 31000 1 of 1....
Benzidine....... ................ ................ Risk <1E-6 Risk <1E-6 Risk =2E-5 Risk =1E-4 6.3 1 of 1.... ..........
Combined Insignificant ................ Risk <1E-6 Risk <1E-6 Risk =5E-5 Risk =2E-4
carcinogen risk. risk for any
constituent.
--------------------------------------------------------------------------------------------------------------------------------------------------------
*Risk numbers based on HBL for 1,2-diphenylhydrazine.
**Inhalation exposure through air pathway.
***Exposure through ingestion of contaminated ground water.

Notes:
All concentrations are in mg/l.
J(#)--Samples where estimated concentrations are below quantitation limits, `(#)' indicates number of samples that are `J' values.

As shown in Table II-9, benzidine is present in this wastestream at
concentrations that pose a substantial risk to human health and the
environment (i.e., equal to or greater than 1E-5 for carcinogens) for
the municipal landfill management scenario. Benzidine was found to be
present in several wastestreams from the manufacture of triarylmethane
pigments using aniline as a feedstock, including wastewaters from both
facilities that manufacture these pigments. The Agency believes that
benzidine is either a raw material contaminant or a reaction by-product
from the process.
Large quantities of aniline, typically in excess, are used as a raw
material to this process. As a result, this wastestream was found to
contain over three percent aniline. The calculated high-end individual
cancer-risk level for aniline is 8E-5 for the landfill scenario.
In addition to benzidine and aniline, the waste was found to
contain two other hazardous constituents that are believed to be by-
products of the reaction and pose a significant risk at the
concentrations detected for the municipal landfill management scenario.
Two additional compounds presented in Table II-9, 1,2-
diphenylhydrazine and azobenzene, coelute on the mass spectrum (see
Section II.D, Description of Health and Risk Assessments, for a
discussion on the Agency's approach to risk assessment for coeluting
compounds). Both compounds are likely oxidation products of aniline,
and may be present in the waste as reaction by-products. In addition to
the uncertainty in establishing concentrations for each of the two
compounds, the chemical pathway from aniline to these oxidation
products suggests that either contaminant may be present at all or part
of the concentration detected. The Agency conducted the risk assessment
using the health-based levels for 1,2-diphenylhydrazine and azobenzene,
independently. For disposal in a municipal landfill, the calculated
high-end individual cancer-risk level for these coeluting compounds,
based on the toxicity of 1,2-diphenylhydrazine, is 2E-5.
In addition to assessing the risks associated with the individual
constituents found in the waste, the Agency considers the combined risk
of constituents that co-exist in the wastestream. In the case of this
wastewater treatment sludge, all of the constituents discussed above
(i.e., aniline, benzidine, and 1,2-diphenylhydrazine/azobenzene) are
believed to co-exist in the wastestream. The processes that produce
triarylmethane pigments using aniline as a feedstock are operated
continuously all year. As a result, the constituents detected in the
wastestream are likely to be present simultaneously in the waste.
Therefore, the combined calculated risk of these individual
constituents, for the municipal landfill scenario would be 2E-4 at the
high end.
However, the risks associated with the current and plausible
management practice for this wastestream (blending with non-hazardous
fuel for combustion) are insignificant. As discussed in Section II.D,
Description of Health and Risk Assessments, the Agency believes that
the fuel blending will continue. The relatively high organic content of
the waste gives the material value as a fuel ingredient and, therefore,
generators of this waste have an economic incentive to continue fuel
blending. Therefore, the Agency is proposing not to list the
wastestream as hazardous. If the NPDES program requirements were to
change (i.e., become more stringent) then those triarylmethane pigment
producers that currently do not generate a sludge could be forced to
generate a sludge due to their efforts to meet new NPDES requirements.
In that case, the plausible management scenario would change, and other
practices, such as landfilling, would become possible. The Agency may
reopen this listing decision should this occur, and will use the risk
levels associated with this management scenario to make a revised
listing determination.
b. Wastewaters from the production of triarylmethane pigments using
aniline as a feedstock.
Summary
The Agency is proposing not to list as hazardous wastewaters from
the production of triarylmethane pigments using aniline as a feedstock.
As shown in Table II-10, these wastewaters contain an average aniline
concentration of 200 ppm. In addition, the wastewaters contain the same
hazardous by-products found in the wastewater treatment sludge.
Although this wastestream, if managed in surface impoundments, would
meet the criteria set out in 40 CFR 261.11(a)(3) for listing a waste as
hazardous and would be capable of posing a substantial present or
potential risk to human health or the environment if released into the
environment, the Agency has determined that management in surface
impoundments is not plausible for this wastestream. The Agency believes
this because 100% of this wastestream is managed in exempt tanks. The
Agency has no reason to believe that this management practice will
change. Risk associated with treatment in tanks is insignificant and,
thus, the Agency is proposing not to list this waste as hazardous.
However, for comparison purposes, the Agency has calculated the risks
associated with disposal of this wastestream in a surface impoundment.
If, based on comments, the Agency determines that it is not reasonable
to assume that management in tanks is the correct plausible management
scenario, the Agency probably would determine that management in a
surface impoundment is the appropriate plausible management scenario.
Discussion
These wastewaters are generated from filtrations of process
intermediates and products, flushing operations, equipment washdowns,
floor washings, and process operations. Based on response data from the
1991 RCRA Section 3007 Questionnaire, a total of 757,080 metric tons,
or 0.4 million gallons per day, of wastewater from the production of
triarylmethane (TAM) pigments is generated. Information on generation
relevant to this discussion is not included at the present time due to
business confidentiality concerns. All of the wastewaters generated
from TAM pigment production (using aniline as a feedstock) are treated
in tanks prior to discharge to a POTW. The data presented in Table II-
10 represent three samples collected from two TAM pigment-manufacturing
facilities.

Table II-10.--Waste Characterization and Risk Estimates Wastewaters From the Production of Triarylmethane Pigments Using Aniline as a Feedstock
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Plausible management Other management Waste Characterization
--------------------------------------------------------------------------------------------------------------------------------------------------------------------
Treat in tanks** Treat in SI*** Treat in SI***
Constituents of concern ----------------------------------------------------------------------------------------------------------- Avg. High Low
Central Central conc. conc. conc. # of pts Notes
Central tendency High end tendency High end tendency High end
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1,2-dipheny- lhydrazine/ Insignificant risks for .......................... .......... .......... Risk=5E-6 R=1E-5 f.n. f.n. 0.093 f.n. J(2)
Azoben- zene*. any constituent. (J)
Aniline.................... .......................... .......................... .......... .......... Risk=7E-5 R=1E-4 f.n. f.n. 108 f.n.
Benzidine.................. .......................... .......................... .......... .......... Risk=1E-4 R=3E-4 f.n. f.n. 0.006 f.n.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Combined Carcinogenic Risk. .......................... .......................... .......... .......... Risk=2E-4 R=5E-4
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
*Risk numbers based on HBL for 1,2-diphenylhydrazine.
**Inhalation exposure through air pathway.
***Exposure through ingestion of ground water.

f.n. Relevant data are not included at the present time due to business confidentiality concerns.

Notes: All concentrations are in mg/l.
J(#)--Samples where estimated concentrations are below quantitation limits, `(#)' indicates number of samples that are `J' values.

As discussed earlier under Section II.D, Description of Health and
Risk Assessments, the plausible management scenario selected for
wastewaters usually is treatment in surface impoundments.
The risks associated with disposing these wastewaters in surface
impoundments would be very high. Two hazardous constituents (aniline
and benzidine) are present in the waste at concentrations that would
pose substantial risks to human health and the environment (i.e.,
greater than 1E-4 for carcinogens) for treatment in a surface
impoundment. Large quantities of aniline, used in excess, are used as a
raw material in this process. As a result, very high concentrations of
aniline are present in the process waters. Even after recovery
operations, EPA found high concentrations of aniline (in this case, an
average of 200 ppm) remaining in the wastewater effluent discharged to
the POTW.
Benzidine was found to be present in several wastestreams from the
manufacture of triarylmethane pigments using aniline as a feedstock,
and is believed to be either a raw material contaminant or a reaction
by-product. The risks posed by benzidine at the concentrations present
in these wastewaters are 3E-4, using a surface impoundment management
scenario.
The coeluting constituents, 1,2-diphenylhydrazine and azobenzene,
which are likely by-products arising from the oxidation of aniline are
present in the waste at a concentration resulting in a calculated risk
level of 1E-5, based on the toxicity of 1,2-diphenylhydrazine (see
Section II.D, Description of Health and Risk Assessments, for a
discussion on the Agency's approach to risk assessment for coeluting
compounds). The mass spectrum representing these two coeluting
compounds was identified in all three wastewater samples collected from
triarylmethane pigment operations.
However, based on the insignificant risks associated with the
current and plausible management practice for this wastestream
(treatment in tanks), EPA is proposing not to list wastewaters from the
production of TAM pigments as hazardous. Although this wastestream
would be hazardous if used for spray irrigation or handled in surface
impoundments, the Agency does not believe that such management is
plausible. The facilities generating the wastewater already are 100%
invested in treating the waste in tanks prior to sending it to a POTW.
In addition, this is not a strongly expanding segment of the industry,
so the Agency does not anticipate more facilities starting up similar
operations. Further, there is a general bias under most State
industrial waste programs against allowing surface impoundments to be
built. Thus, based on the risk associated with treatment in tanks, the
Agency is proposing not to list this wastestream as hazardous.
c. Still bottoms or heavy ends from the production of
triarylmethane dyes or pigments (K166).
Summary
The Agency is proposing to list still bottoms or heavy ends from
the production of triarylmethane dyes or pigments as hazardous. This
wastestream meets the criteria set out at 40 CFR 261.11(a)(3) for
listing a waste as hazardous and is capable of posing a substantial
present or potential risk to human health or the environment. Based on
ingestion of contaminated ground water, EPA calculated high-end
individual risk levels (greater than 1E-4) for carcinogens under both
the baseline and plausible management scenarios. Two carcinogens pose
high-end risks exceeding 9E-3 for the plausible management scenario of
disposal in an on-site monofill. These two constituents pose very high
levels of risk (greater than 1E-3) for the baseline management practice
of disposal in a municipal landfill. In addition, one of these
constituents has an HQ of 6 for the air pathway associated with
management in an on-site boiler, a practice which is both a baseline
management practice and a plausible management scenario.
Discussion
This wastestream includes distillation bottoms from the production
of triarylmethane dye and pigments, which are generated from solvent
and raw material recovery operations (i.e., recovery of aniline,
dimethylaniline, or other solvents).

Table II-11.--Waste Characterization and Risk Estimates K166--Still Bottoms or Heavy Ends From the Production of Triarylmethane Pigments Using Aniline
as a Feedstock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline management Plausible management Waste characterization
--------------------------------------------------------------------------------------------------------------------------------------
Constituents of On-site boiler Municipal landfill On-site boiler On-site monofill
concern ---------------------------------------------------------------------------------------- Avg. High Low
Central Central Central Central conc. conc. conc. # of pts Notes
tend. High end tend. High end tend. High end tend. High end
--------------------------------------------------------------------------------------------------------------------------------------------------------
1,2-dip- henyl- R=2E-6 R=6E-5 R=6E-4 R=2E-3 R=7E-6 R=1E-5 R>9E-3 R>9E-3 f.n. f.n. 1700 2 of 2..
hydra- zine/ Azo-
ben- zene*.
Aniline.......... HQ<1 HQ=6 R=2E-3 R=7E-3 HQ=3 HQ=6 R>9E-3 f.n. f.n. 19000 2 of 2
N-nitro- sodi- no air no air R<1E-6 R<1E-6 no air no air R=1E-6 R=6E-6 580 ....... ....... 1 of 2.. J
phenyl- amine/ HBL HBL HBL HBL
Di- phenyl-
amine **.
Combined R=2E-6 R=6E-5 R=2E-3 R=9E-3 R=2E-5 R=6E-5 R>9E-3 R>9E-3
Carcinogen Risk.
--------------------------------------------------------------------------------------------------------------------------------------------------------
*Risk numbers based on HBL for 1,2-diphenylhydrazine.
**Risk numbers based on HBL for N-nitrosodiphenylamine.

f.n. Relevant data are not included at the present time due to business confidentiality concerns.

Notes:
All concentrations are in mg/kg.
J(#)--Samples where estimated concentrations are below quantitation limits, `(#)' indicates number of samples that are `J' values.

Information relevant to this discussion is not included at the
present time due to business confidentiality concerns.
Process waters from the manufacture of triarylmethane dyes and
pigments containing high levels of aniline or other raw materials and
solvents sometimes are sent to a distillation column for recovery of
the material for reuse in the process. As expected, the bottoms
generated from the distillation contain high concentrations of the
material being recovered. The concentrations of aniline present in two
samples collected exemplify the concentrations of solvent contaminants
anticipated in these wastes. Information on the concentration of
aniline observed is not presented at his time due to business
confidentiality concerns.
Based on data from the RCRA Section 3007 Questionnaire, four
facilities generated a total of 1700 metric tons of this waste in 1991.
EPA has summarized the risk projections associated with this waste
in Table II-11. The data presented in this table represent two samples
from two facilities. These samples were collected from the two largest
generators of this wastestream, both of which recover aniline from the
wastewater. One of the remaining two facilities recovers other aniline
derivatives (i.e., N,N- dimethylaniline and N,N-diethylaniline) that
are used as raw materials and solvents in the production of
triarylmethane dyes. The second facility recovers chlorobenzene used as
a solvent in the production of triarylmethane dyes and generates a
still bottom waste that is reported to contain 50% chlorobenzene. This
waste is already listed as F002, based on the use of the solvent
chlorobenzene. Based on an evaluation of the processes generating these
wastes and the contaminants reported to be present by industry, the
Agency believes the risks posed are similar to those assessed in Table
II-11. The data used to characterize these wastestreams, assess the
risks posed by these wastes, and make a proposed listing determination
on the waste grouping were obtained from the two samples collected by
EPA and the 1991 RCRA Section 3007 Questionnaire responses. Waste
management information relevant to this discussion are not included at
the present time due to business confidentiality concerns.
As discussed earlier in Section II.D, Description of Health and
Risk Assessments, the Agency conducted the risk assessment on these
wastestreams using the two most widely used practices, the on-site
boiler and municipal landfill as the current management scenario, and
an on-site boiler (for the air pathway) and on-site monofill (for the
ground-water pathway) as the plausible management scenario.
The risk posed by the presence of aniline in the concentrations
found in the waste is estimated to be very high (i.e., greater than 9E-
3 for the ground-water pathway, and HQ=6 for the air pathway). Due to
the imperfect nature of any recovery process, it is not unexpected that
large quantities of aniline, or any other raw material or solvent being
recovered, would be present in these still bottoms. Aniline was found
in very high concentrations (i.e., the low concentration was 1.9%) in
both distillation bottom samples collected from triarylmethane pigment
production. Information on the high concentration value is not included
at the present time due to business confidentiality concerns.
In addition to aniline, the two sets of coeluting constituents
present in the wastewater treatment sludge and wastewaters from these
operations (i.e., 1,2-diphenylhydrazine and azobenzene, and N-
nitrosodiphenylamine and diphenylamine) also are present in the
distillation bottoms (K166). These compounds are all likely by-products
arising from the oxidation of aniline. The MS curve representing 1,2-
diphenylhydrazine and azobenzene was identified in both distillation
bottom samples collected from triarylmethane pigment operations. For
the reasons discussed in Section II.D, the Agency conducted the risk
assessment for these coeluting compounds independently. The resulting
high-end individual cancer-risk level for this first set of coeluting
compounds is greater than 9E-3. Likewise, the risk assessment for N-
nitrosodiphenylamine and diphenylamine was conducted independently, as
discussed in Section II.D. The resulting high-end individual cancer-
risk level for this second set of coeluting compounds is 6E-6.
In addition to assessing the risks associated with the individual
constituents found in the waste, the Agency considers the combined
risks of constituents that co-exist in the wastestream. In the case of
still bottoms from the production of triarylmethane dyes and pigments,
all of the constituents are believed to co-exist in the wastestream.
The distillation columns generating this residual process the same
wastestream with each dye or pigment batch. As a result, the
constituents detected are likely to be present simultaneously in the
waste. The risk of each individual constituent is high, and the
combined risks of these constituents are very high (greater than 9E-3
for the ground-water pathway and 6E-5 for the air pathway), both of
which were considered in making this listing determination.
In addition to the very high risks posed by the plausible
management practice (on-site boiler for the air pathway and on-site
monofill for the ground-water pathway), the risks posed by the baseline
management practice (on-site boiler for the air pathway and municipal
landfill for the ground-water pathway) are also very high.
Specifically, the risks posed by the current management practices are
greater than 9E-3 for the ground-water pathway, and 6E-5 (carcinogens)
and HQ=6 (non-carcinogens) for the air pathway.
In summary, the calculated risks associated with managing these
still bottoms in on-site boilers, municipal landfills, and on-site
monofills are all very high, based on each of the individual hazardous
constituents in the wastestream and the combined risks due to
carcinogens found in the wastestream as a whole. Therefore, based on
the risks associated with both current management and plausible
management practices for this waste, EPA is proposing to list as
hazardous still bottoms or heavy ends from the production of
triarylmethane dyes or pigments, designated EPA Hazardous Waste Number
K166.
For the reasons stated above, the Agency is proposing to add the
following constituents to Appendix VII to Part 261--Basis for Listing:
1,2-diphenylhydrazine, azobenzene, aniline, diphenylamine, and N-
nitrosodiphenylamine.
In addition, azobenzene and N-nitrosodiphenylamine are proposed to
be added to Appendix VIII to Part 261--Hazardous Constituents.
5.Wastes from the production of anthraquinone dyes and pigments.
a. Wastewater treatment sludge from the production of anthraquinone
dyes and pigments.
Summary
EPA is proposing to defer the proposed listing determination for
wastewater treatment sludges from the production of anthraquinone dyes
and pigments at this time. Based on analysis of the sludge samples
collected by the Agency, no constituents attributable to anthraquinone
processes were detected. However, data supplied by industry indicate
the presence of two constituents on the target analyte list for which
no health-based levels and no adequate surrogates exist. Based on this
discrepancy and the need to identify surrogates for risk analysis, the
Agency believes a deferral is appropriate for this wastestream.
Discussion
This sludge is generated from the treatment of wastewaters from
anthraquinone dye and pigment manufacturing. Volume information
reported by industry in the 1992 RCRA 3007 Questionnaire data is not
included at the present time due to business confidentiality concerns.
Wastewater treatment sludge from the production of anthraquinone
dyes and pigments is generated at 11 facilities. Sludge generated from
9 of the 11 facilities, which represents over 98% of the anthraquinone
dye and pigment production volume, is commingled with wastewater
treatment sludge from the production of azo pigments and/or dyes. Over
98% of the commingled sludge currently is managed in municipal
landfills or is disposed in on-site monofills. Small fractions of the
commingled sludge are managed under Subtitle C. Waste management and
waste volume information relevant to this discussion is not included at
the present time due to business confidentiality concerns.
Of the 11 facilities that generate this waste, the Agency collected
samples from the three largest contributors to the wastestream and from
one small contributor. Several compounds used in anthraquinone dye or
pigment operations were expected to be present in the waste, based on
facility production schedules, and were not detected. In addition,
analysis of these samples did not produce any other contaminants
attributable to anthraquinone dye or pigment operations (refer to the
Background Document for this rulemaking located in the RCRA Docket for
this rule (see ADDRESSES section) for the methodology used in
identifying contaminants attributable to a process).
Several compounds used in the manufacture of anthraquinone dyes and
pigments were dropped from the Agency's target analyte list for dye and
pigment wastes, due to the absence of any health effects information
and because of low usage rates (i.e., the compound was used at only 1
or 2 facilities). Examples of anthraquinone-related compounds dropped
from the target analyte list for these reasons include: 1-
chloroanthraquinone, 1,4- dihydroxyanthraquinone-2-sulfonic acid, 1-
amino-2-chloro-4- hydroxyanthraquinone, and 1-amino-4-bromo-2-
anthraquinonesulfonic acid.
As stated above, the Agency's analysis of wastewater treatment
sludge samples collected from anthraquinone dye and pigment operations
did not produce any contaminants attributable to anthraquinone dye or
pigment operations. However, industry data submitted on 11 sludge
samples confirmed the presence of two target analytes, 1-
aminoanthraquinone, and leucoquinizarine, at average concentrations of
1.5, and 1.4 ppm, respectively. Each of the two analytes was detected
in three of the 11 samples.
The Agency did not find HBLs for either of the two compounds
detected in this wastestream, 1-aminoanthraquinone and
leucoquinizarine. In addition, the Agency was not able to identify any
appropriate surrogate compounds to represent the toxicity of these
compounds. If one or both of these compounds are potential carcinogens
and behave in a similar manner to the potential carcinogen, 1-amino-2-
methyl-anthraquinone, then the risk posed by the presence of the
compounds in the waste would need to be examined further. The Agency is
concerned about using this limited surrogate information as a basis for
listing this waste as hazardous.
In summary, the Agency is proposing to defer a listing
determination for wastewater treatment sludge from the manufacture of
anthraquinone dyes and pigments at this time, and is requesting data on
the toxicity of 1-aminoanthraquinone and leucoquinizarine or
information on suitable surrogates for these compounds. EPA also would
be interested in submission of further characterization data. EPA will
evaluate carefully all public comments and information received in
response to this notice. Based on comments or data received, the
Agency, rather than deferring, may choose to promulgate a final
determination to either list or not to list this waste as hazardous
under RCRA.
b. Wastewaters from the production of anthraquinone dyes and
pigments.
Summary
EPA is proposing not to list wastewaters from the production of
anthraquinone dyes and pigments as hazardous. This wastestream is not
considered to pose significant risks to human health and the
environment, based on the analysis of samples of the waste. Several
compounds used in the manufacture of anthraquinone dyes and pigments
were expected to be present in the waste but were not detected. Only
one compound attributable to anthraquinone processes, 3-
aminoacetanilide, was detected in the waste, at low concentrations.
Health effects information on this constituent does not currently
exist, and risk estimates conducted using methylenephenylenediamine as
a surrogate indicate no significant risks.
Discussion
Based on response data from the RCRA Section 3007 Questionnaire,
the 1991 volume reported by the industry for wastewaters from
anthraquinone dye and pigment production was 3,988,166 metric tons, or
approximately 2.9 million gallons per day, generated at 25 facilities.
Most of the wastewater currently is treated and discharged to a surface
water under the NPDES system; the remainder is discharged to a POTW
(with 5% pretreated prior to discharge). Additional information on
volumes and waste managment is not included at the present time due to
business confidentiality concerns.
Of the 25 facilities that generate this waste, the Agency collected
a total of seven samples from the four largest contributors to the
wastestream and from one small contributor. Information relevant to
this discussion is not included at the present time due to business
confidentiality concerns.
As stated above, several compounds used in anthraquinone dye and
pigment operations were expected to be present in the waste, based on
facility production schedules, and were not detected. In addition, only
one compound attributable to anthraquinone dye and pigment production
was detected in the waste (refer to the Background Document for this
rulemaking located in the RCRA Docket for this rule (see ADDRESSES
section) for the methodology used in identifying contaminants
attributable to a process). This compound, 3-aminoacetanilide, was
present in five of the seven samples collected, at an average
concentration of 0.15 ppm. However, health effects information needed
to assess the risk posed by this constituent does not currently exist.
In order to estimate the potential risk from 3-aminoacetanilide, the
Agency performed a risk assessment using methylenephenylenediamine as a
surrogate compound. The Agency selected a surrogate compound that is
structurally similar to the compound detected in the waste (i.e., 3-
aminoacetanilide), and is estimated, by means of structural activity
relationships (SARs), to be more toxic than the subject compound. This
assessment produced a groundwater concentration, prior to dilution and
attenuation, of 1.5 times the HBL. Thus, the concentration at the
receptor well, following dilution and attenuation, would be expected to
be less than the HBL. More detailed discussions on the risk assessment
screening and surrogate compounds are presented in Section II.D of this
preamble, Description of Health and Risk Assessments, and the Listing
Background Document for this proposed rule, which is located in the
RCRA Docket for this rulemaking (see ADDRESSES section).
In conclusion, because the one compound attributable to
anthraquinone dye or pigment production detected in this waste is
present in low concentrations, does not have health data needed to
assess risk, and does not indicate a risk using surrogate toxicity
data, the Agency is proposing not to list wastewaters from the
manufacture of anthraquinone dyes and pigments as hazardous.
6.Wastewaters from the production of FD&C colorants.
Summary
EPA is proposing not to list wastewaters from the production of
FD&C colorants as hazardous wastes. This wastestream is not considered
to pose significant risks to human health and the environment, based on
the analysis of samples of the waste. Only three constituents
attributable to FD&C colorant processes were detected in the waste, and
these do not present a risk at the concentrations observed.
Discussion
Based on the 1991 RCRA Section 3007 Questionnaire data, the volume
reported by the industry for the wastewater stream from FD&C colorant
production is 3,557,563 metric tons per year, or 2.6 million gallons
per day. Information on the percentage of these wastewaters that are
currently pretreated and discharged to a POTW and other waste
management information relevant to this discussion is not included at
the present time due to business confidentiality concerns.
The Agency collected three samples of wastewaters generated from
FD&C operations and did not find any hazardous constituents present at
concentrations that pose a risk above EPA's initial risk ``level of
concern'' (i.e., 1E-5 for carcinogens, and HQ of 1 or greater). The
Agency believes that the samples of wastewaters from the manufacture of
FD&C colorants are representative of the industry. In fact, wastewater
samples were collected from the two largest-volume FD&C colorant
producers in the country, in addition to one smaller manufacturer.
Several of the raw materials used in the manufacture of FD&C
colorants were dropped from the Agency's target analyte list for
analysis of dye and pigment wastes because the few existing health
studies on these compounds indicate that the compounds are non-toxic.
In addition, many of the raw materials used in the manufacture of FD&C
colorants are compounds that contain sulfonic acid functional groups,
for which analytical methods do not exist. Examples of FD&C raw
materials dropped from the target analyte list for these reasons
include p-toluidine-m-sulfonic acid, and sulfanilic acid.
The sulfonic acid functional group imparts water solubility to a
compound, which generally results in lower toxicity. However, several
of these materials may pose a risk when present in the wastestream
without the sulfonic acid functional group. For example, without
sulfonic acid functional groups, the two compounds listed above (p-
toluidine-m-sulfonic acid and sulfanilic acid) are represented by p-
toluidine, and aniline, respectively. In these cases, the precursors to
the FD&C reactants (i.e., prior to sulfonation) remained as target
analytes even when the sulfonated compounds were not on the list.
Information relevant to this discussion is not included due to business
confidentiality concerns. (Refer to the Dye and Pigment Listing
Background Document, located in the RCRA Docket for this proposed
rulemaking (see ADDRESSES section), for details on the development of
the target analyte list.)
From the three FD&C wastewater samples collected, the following
three constituents were observed that are attributable to FD&C colorant
production: Aniline, 3-hydroxyphenol, and phenol. During the risk
assessment screening, the Agency found that the three constituents
present in the waste (i.e., aniline, 3-hydroxyphenol, and phenol) do
not pose a risk at the concentrations detected. In fact, the ratios of
maximum measured concentration in the wastestream to the HBL were less
than 1 for aniline and phenol. Since there currently is no HBL
available for 3-hydroxyphenol, the concentration of 3-hydroxyphenol was
compared to that of a surrogate. 3-Hydroxyphenol is not expected to be
a potential carcinogen. Furthermore, the Agency selected a surrogate
compound that is structurally similar to the compound detected in the
waste, and is estimated, by means of structural activity relationships
(SARs), to be more toxic than the subject compound. Therefore, phenol
was selected as a surrogate for this 3-hydroxyphenol, and the resulting
ratio of concentration to HBL was also less than 1. This indicates that
if the contaminant concentrations found in the waste were actually
present in drinking water, the risks posed by ingesting the drinking
water would be insignificant.
In conclusion, because the constituents in this wastestream were
observed at concentrations that present insignificant risks, and no
other hazardous constituents attributed to FD&C colorant production
were detected, the Agency is proposing not to list wastewaters from the
manufacture of FD&C colorants as hazardous.
7. Dusts and dust collector fines from the manufacture of dyes and
pigments.
Summary
The Agency is proposing not to list dusts and dust collector fines
from the manufacture of dyes and pigments because, based on an
evaluation of current management and plausible management, this waste
does not pose a substantial potential hazard to human health and the
environment.
Discussion
Dusts and dust collector fines are generated during drying,
grinding, and blending operations that occur during the manufacture of
dyes and pigments. Dust collectors and baghouses generally are used to
capture and collect the dust. The total volume of this wastestream
reported in response to the 1991 RCRA Section 3007 Questionnaire is 143
metric tons. According to questionnaire data, some of the dusts and
fines reported by the industry are recovered and recycled back to the
manufacturing process or sold to shoe-polish manufacturers as a raw
material. Information on the percentage handled in this manner is not
included at the present time due to business confidentiality concerns.
There is a distinct economic incentive for these facilities to continue
reusing or selling dusts and fines in this way. This handling of dusts
and fines is not expected to present any significant risk to human
health and the environment.
Seventeen percent of the reported waste volume is generated by a
facility that currently manages dusts and fines in a Subtitle C
landfill and the Agency believes that this facility will continue to
manage dusts and fines in such a manner. The dusts and fines generated
at this facility from organic pigments covered by this listing
determination are mixed with dusts and fines from inorganic pigments
that contain lead and chromium. The entire volume of dusts and fines,
comprised of the commingled organic and inorganic products dusts and
fines, is characteristically toxic for both lead and chromium and,
therefore, is a hazardous waste as defined by 40 CFR 261.24. It is
impractical for the facility to separate the dusts and fines covered by
this listing determination from these characteristic inorganic dusts
and fines and, thus, the facility manages the dusts and fines covered
by this listing determination in a Subtitle C landfill. Analysis of
existing plant design shows that dusts and fines are comingled in
ductwork that is structured such that these wastes are mixed. Without
significant re-design and construction, segregation of the wastes is
impossible. The Agency does not believe that it is plausible for the
facility to discontinue the practice of combining all of its dusts and
fines wastes and disposing of such wastes at a Subtitle C facility
given the physical arrangement of this facility. Management of this
waste in a Subtitle C landfill is not expected to pose any significant
level of risk to human health or the environment.
Information on the volume and the percentage of total volume
disposed of in Subtitle D landfills is not included at the present time
due to business confidentiality concerns.
The Agency believes the potential risks posed by the plausible
management practices for this volume do not warrant a hazardous waste
listing for dusts and fines.
Although, due to resource constraints, the Agency was unable to
collect information on the characteristics of these dusts and fines,
the Agency estimated a worst-case risk by estimating the risk
associated with disposal of dusts and fines in a Subtitle D landfill
based on the physical/chemical properties of a mobile dye product and
the toxicological properties of a dye constituent known to be one of
the most toxic and mobile dye or pigment waste constituents. This
analysis demonstrated that the risk is below the initial level of
concern associated with disposal of this waste in a Subtitle D
landfill. Management of this waste in an on-site monofill was
determined to be not plausible because the volumes generated would not
justify an on-site monofill. For further information see the background
document on risk assessment, available in the public docket for this
rule.
The Agency requests comment on the approach used to determine risk
posed by plausible management of the wastes and requests comment on the
proposed determination not to list this waste.
9. Spent filter aids, diatomaceous earth, or adsorbents used in the
production of azo, anthraquinone, or triarylmethane dyes, pigments, or
FD&C colorants.
Summary
The Agency is proposing to defer a determination on whether to list
spent filter aids, diatomaceous earth, or adsorbents used in the
production of azo, anthraquinone, or triarylmethane dyes, pigments, or
FD&C colorants as hazardous due to insufficient waste characterization
data. The Agency is planning to collect additional information on this
wastestream. EPA then will publish a supplemental notice with a
proposed determination on whether to list this waste.

III. Waste Minimization

In the Pollution Prevention Act of 1990 (42 U.S.C. 13101 et seq.,
Pub. L. 101-508, November 5, 1990), Congress declared pollution
prevention the national policy of the United States. The act declares
that pollution should be prevented or reduced whenever feasible;
pollution that cannot be prevented should be recycled or reused in an
environmentally safe manner wherever feasible; pollution that cannot be
prevented/reduced or recycled should be treated; and disposal or
release into the environment should be chosen only as a last resort.
This section first provides a general discussion of some generic
pollution prevention and waste minimization techniques that facilities
may wish to explore and second discusses and requests comment on ways
in which the hazardous waste listing determination program itself could
be structured to better promote pollution prevention and waste
minimization.

A. Generic Approaches to Waste Minimization

Waste minimization practices fall into three general groups: change
in production practices, housekeeping practices, and practices that
employ the use of equipment that by design promote waste minimization.
Some of these practices/equipment listed below conserve water, others
reduce the amount of product in the wastestream, while others may
prevent the creation of the waste altogether. EPA acknowledges that
some of these practices/equipment may lead to media transfers or
increased energy consumption. This information is presented for general
information, and is not being proposed as a regulatory requirement.
Production practices include:
Triple-rinsing raw material shipping containers and
returning the rinsate directly to the reactor;
Scheduling production to minimize changeover cleanouts;
Segregating equipment by individual product or product
``families;''
Packaging products directly out of reactors;
Steam stripping wastewaters to recovery reactants or
solvents for reuse;
Using raw material drums for packaging final products; and
Dedicating equipment for hard to clean products.
Housekeeping practices include:
Performing preventive maintenance on all valves, fittings,
and pumps;
Promptly correcting any leaky valves and fittings;
Placing drip pans under valves and fittings to contain
leaks; and
Cleaning up spills or leaks in bulk containment areas to
prevent contamination of storm or wash wasters.

Equipment promoting waste minimization by reducing or eliminating waste
generation include:
Low-volume/high-pressure hoses for cleaning;
Drum triple-rinsing stations;
Reactor scrubber systems designed to return captured
reactants to the next batch rather than to disposal;
Material storage tanks with inert liners to prevent
contamination of water blankets with contaminants which would prohibit
its use in the process; and
Enclosed automated product handling equipment to eliminate
manual product packaging.
Waste minimization measures can be tailored to the needs of
individual industries, processes, and firms. This approach may make it
possible to achieve greater pollution reduction with less cost and
disruption to the firm.
Defined process control and good housekeeping practices often can
result in significant waste volume or toxicity reduction. Evaluations
of existing processes also may point out the need for more complex
engineering approaches (e.g., waste reuse, secondary processing of
distillation bottoms, and use of vacuum pumps instead of steam jets) to
achieve waste minimization objectives. Simple physical audits of
current waste generation and in-plant management practices for the
wastes also can yield positive results. These audits often turn up
simple non-engineering practices that can be implemented successfully.

B. Waste Minimization Approaches in the Listing Program

Section 1003 of the Hazardous and Solid Waste Amendments of 1984
says that one of RCRA's goals is to promote protection of human health
and the environment and to conserve valuable material and energy
resources by ``minimizing the generation of hazardous waste and the
land disposal of hazardous waste by encouraging process substitution,
materials recovery, properly conducted recycling, and reuse and
treatment.'' Section 1003 further provides that it is a national policy
of the United States that, whenever feasible, the generation of
hazardous waste is to be reduced or eliminated as expeditiously as
possible. To further EPA's waste minimization goals, the Waste
Minimization Branch (WMB) in EPA's Office of Solid Waste (OSW)
established the RCRA Waste Minimization Action Plan to integrate source
reduction and recycling into the National RCRA Program, and RCRA
activities into the Agency's Pollution Prevention Strategy.
As described in that plan, EPA's program for evaluating which
wastes should be listed as hazardous is an example of a regulatory
program that can provide opportunities for encouraging and promoting
real waste minimization. When a wastestream is listed as hazardous, it
enters the hazardous waste management system. The requirements of that
system can be costly and there are currently only limited ways for a
waste entering the system to get out. Once it is listed as a hazardous
waste, it remains a listed hazardous waste even after treatment and
safe disposal, unless delisted pursuant to 40 CFR 260.20 and 260.22.
Other than levels at which wastes typically are delisted, there is no
target for a generator to shoot for which would allow their waste to be
considered non-hazardous even if waste minimization actions are taken
that ensure the waste is not likely to pose a hazard to human health
and the environment. However, if a waste minimization-based exemption
to the listing could be provided, generators would have the regulatory
and economic incentive to meet the exemption. When the exemption is
tailored to encourage and reward waste minimization efforts, then the
generator could obtain the benefit of not generating a listed hazardous
waste while furthering national waste minimization goals.
The Agency notes that there are several important considerations in
developing listing determinations that encourage waste minimization.
First, waste minimization-based listings must promote actual waste
minimization and clearly not increase risk. In addition, the listings
must be enforceable.
1. Actual Waste Minimization Must Occur. The Agency is interested
in taking comment on developing listings that encourage reductions in
volumes, reductions in concentrations of constituents of concern
(without diluting constituents in an effort to reduce concentration),
reductions in environmental loading of constituents of concern, and/or
the removal of constituents of concern (or process derivatives of
concern) from the manufacturing process, and/or the beneficial reuse,
recycling, or reclamation of the wastestreams themselves, provided
human health and the environment is protected. A waste minimization-
based listing, for example, must be crafted so as not to result simply
in cross-media transfer, and so as not to leave uncontrolled wastes
reduced in volume or concentration, but still posing a significant
hazard. The Agency believes that generators must make a commitment that
waste minimization in fact would occur, and that a real investment in
waste minimization techniques, equipment, and process changes would be
carried out.
2. No Increase in Risk Can Occur. A waste minimization-based
listing (or variable level) must protect human health and the
environment and not increase risk. A hazardous waste listing achieves
the goal of minimizing risk by placing a wastestream in the hazardous
waste management system. Any exemption which takes a wastestream out of
this system must be shown to provide an equivalent decrease in risk as
that provided by the listing itself. It would be unacceptable, for
example, for waste minimization actions simply to result in cross-media
transfer of wastes. Chemical substitution that fails to reduce the
risks posed by a wastestream is another example of a practice that
would not be considered to be waste minimization. Another specific
concern involves the possible presence of other constituents in a
wastestream for which the waste was not specifically listed but which
also may pose risk to human health or the environment. A waste
minimization-based listing must consider the impact of letting the
entire wastestream out of the hazardous waste management system.
3. Enforceability. The Agency is particularly concerned about the
enforceability of waste minimization-based variance to a listing. In
particular, the Agency has concerns about the following factors:
The amount of testing or monitoring required,
Ease by which a State inspector could check compliance,
How a generator would demonstrate compliance with the
waste minimization-based exemption,
The likelihood that a State agency would adopt a waste
minimization approach in its listing regulations, and
The ability of a State agency to oversee an exemption.

Any waste minimization-based listing must account for these concerns.
(Many of these issues now are being considered in EPA's deliberations
on the Hazardous Waste Identification Rule.)

C. Specific Approaches to Waste Minimization

The Agency can and has used different regulatory mechanisms to
promote waste minimization in the listing program. The discussion below
will describe several options the Agency has identified as an approach
to tailoring listings that encourages generators to use waste
minimization practices. This approach could apply to any listing
determination. Also included in this discussion are specific references
to today's proposed listing determination for dyes and pigments.
Quantity-Based Listings
A potential method of structuring a waste listing to promote waste
minimization would be to establish a quantity-based exemption for the
wastes listed. Under such an approach, the listing of a specific
wastestream would be accompanied by a quantity-based exemption for the
specific wastestream involved. Quantity can refer to either a
concentration of constituents in a waste (measured or calculated) or
the mass of constituents released to the environment. The Agency
believes that this approach would encourage waste minimization because
a facility would have to meet a risk-based quantitation target for a
wastestream in order to qualify for the exemption, thereby requiring
reductions in the mass or concentration (or both) of the constituents
of concern. In reducing mass loading or concentration (or both) of the
wastes, the Agency's waste minimization goals are achieved.
A concentration basis is easier to measure and track than a limit
based on loading or mass. Setting a limit based on loadings or mass
addresses total loadings to the environment and recognizes waste
minimization efforts that result in reductions in both mass of
pollutant and volume of total wastestream. However, a mass loading
approach poses significantly more burden in terms of monitoring and
compliance and may not take into account concentrations of constituents
in a waste. The Agency requests comment on the use of production or
mass-based limits, and on possible monitoring approaches.
A variation on this approach is an adaptation of the ``headworks
rule'' (40 CFR 261.3(a)(2)(iv)(A)-(E)) to a listing. The original rule,
promulgated on November 17, 1981 (46 FR 56582) allows for calculated
amounts of certain spent solvents, commercial chemical products,
petroleum refining wastes, and laboratory residuals to be sent to a
facility's wastewater treatment plant, and for the wastewaters and
sludges (beyond the headworks) to be exempted from the mixture rule.
The Agency also proposed in the March 1, 1994 carbamates listing
proposal (59 FR 9808-9864) to provide a similar exemption to a
wastewater proposed for listing in the same notice.
Under the ``headworks'' exemption approach (e.g., 40 CFR
261.3(a)(2)(iv)(H)), the wastewaters and treatment sludges would be
exempt from the listing as long as the industry could show that the
total quantity of hazardous constituents that pose risk in a
wastestream, divided by the undiluted wastewater flow for wastewaters
on an average weekly basis from the particular product process subject
to the listing was less than a calculated quantity. The calculated
quantity would be based on a risk assessment.
The Agency would have to be able to determine the relationship
between the amount of raw material used and the presence of particular
constituents in the wastestream. The Agency requests comment on whether
determining such a relationship is feasible for the dye and pigment
industries. To qualify for such an exemption, the facility would have
to use existing inventory records of raw materials that go into the
process. The facility can subtract the quantity of materials that, in
fact, do not go into the wastewater treatment system, either by
chemical reaction or material recovery techniques (i.e., distillation,
reuse, reverse osmosis, etc.). The facility may not subtract any
quantity assumed to volatilize. The quantity of material left then
would be converted to resulting levels of constituents expected to be
generated based on quantity of raw material used. The levels of
constituents then would be divided by the average weekly flow of the
wastewaters into the headworks of the wastewater treatment system at
the time the process is being run to determine total concentrations of
constituents in wastewater. If the total concentration of constituents
of concern is less than the amount calculated based on the risk
assessment, the wastewaters and treatment sludges would qualify for the
exemption. This approach has the advantage of determining
concentrations in a mathematical, rather than an analytical way. The
disadvantage is that it requires collection of process flow data and
specific plant chemistry information.
The Agency realizes that constituent loading into the wastewater
treatment system may have to be reduced significantly (up to two to
three orders of magnitude in many cases) in order to qualify for an
exemption of this sort. Therefore, the Agency solicits comment on
whether such levels are achievable, and what other calculation methods
may exist (such as one based on production mass).
Such an exemption would apply only after the wastewaters have
arrived at the headworks of a facility's wastewater treatment system.
The Agency would not allow it to apply to wastewaters before they reach
the headworks. Generators who wish to qualify for such an exemption
would be required to use flow statistics for the period in which the
processes generating the wastewaters are being run. Finally, such an
exemption would apply only to wastewater flow for that wastestream, not
to flow figures from unrelated processes that serve only to dilute the
wastewaters.
In addition, generators would be required to keep records of
average weekly flow in the production processes, especially when the
processes generating the listed wastewaters are run. When land disposal
restrictions are applied to a waste subject to such an exemption,
generators would need to comply with 40 CFR 268.7(a)(6), which states
that the generator who has produced a waste subject to an exemption in
40 CFR 261.2-261.6 must keep a notification in the facility's file
stating that such a waste has been generated, the fact that it is
restricted, and the disposition of the waste.
The Agency seeks comment on the recordkeeping burden that
accompanies its implementation. The Agency realizes that facilities
that would wish to take advantage of such an exemption would be
required to allow compliance personnel to examine process records
(reaction rates, reactants, process flows, etc.) to verify that a
facility is able to achieve the exemption. Therefore, the Agency
solicits comments on this topic as well.
A quantity-based exemption in a listing determination bears a
strong relationship to another ongoing Agency project which seeks to
establish an exit from the hazardous waste management program. The
Hazardous Waste Identification Rule (HWIR) project is an effort, in
part, to set exit criteria for any listed hazardous waste so that
materials which clearly fail to pose a threat to human health and the
environment can exit the Subtitle C system. The HWIR concept, as
currently envisioned, would be expected to be similar to that of a
quantity-based exemption for a specific listed hazardous waste: a risk-
based exemption process that employs analysis of multiple exposure
pathways to determine a safe exit or exemption level. A principal
difference between the HWIR concept under discussion and a quantity-
based listing could be that HWIR is meant to apply to all listed
wastestreams, while a quantity-based listing could be targeted to a
specific wastestream in a listing determination. In that sense, a
listing exemption could be considered to be more tailored to the known
exposure routes of a specific wastestream and may be able to generate
an exemption level which is specific to that wastestream. For example,
if the listing determination analysis shows a wastestream in a listing
can be managed only in tanks, then the exemption analysis could be
focused on the exposure pathways affected only by tanks. The exemption
levels for that wastestream could be tailored to those exposure routes
(air pathways) and could be different than HWIR exit criteria. The
Agency solicits comment on the advantages and disadvantages of a
quantity-based exemption in listing determinations to a more generic
exit level lkie that being contemplated in the HWIR project
discussions.
Relationship to the Definition of Solid Waste
The Agency has observed in the dye and pigment and other industries
that material recovery may be discouraged due to restrictions placed on
materials designated as ``solid and then hazardous'' waste, as defined
by RCRA. Over the past two years, the Agency's Definition of Solid
Waste Task Force in the Office of Solid Waste examined possible
modifications to the definition of solid waste to encourage
environmentally sound recycling. A final report of the Task Force was
issued on September 19, 1994.
An example in the dye and pigment industries of using as a product
a material that ordinarily would be a waste involves the blending and
sale of collected dusts and fines as inexpensive black pigments useful
to shoe polish manufacturers.

D. Waste Minimization and the Dye and Pigment Industries

The dye and pigment industries have expended considerable effort to
cooperate with the Agency on a voluntary waste minimization program,
coordinated through ETAD. As part of this effort, waste minimization,
recycle, and reuse practices in the dye and pigment industries were
described for all aspects of production in the ``Pollution Prevention
Guidance Manual for the Dye Manufacturing Industry'' (EPA/741/B-92-
001).
The Agency is interested in options to modify today's proposed
listing determinations to support and enhance the voluntary waste
minimization efforts already initiated by the dye and pigment
industries. The Agency requests comment on the feasibility of the waste
minimization-based listing approaches described above for the dye and
pigment industries. EPA also solicits ideas and comments on other
possible approaches to tailor the hazardous waste listings and promote
waste minimization in the dye and pigment industries. In particular,
the Agency requests comment on other approaches that may provide more
flexibility for waste minimization and better assure that constituent
reductions would be achieved through waste minimization (rather than
through treatment).
EPA specifically requests comment on the feasibility of developing
the quantity-based listing approach described above for the dye and
pigment industries. The quantity-based approach is based on the
Agency's experience with other industries in which production is
continuous. Because of the batch nature of production and the
multiplicity of chemicals involved in the dye and pigment industries,
the quantity-based listing approach may be more difficult for this
industry. The Agency requests comment on how these issues (i.e., batch
processes, multiple chemicals) might be addressed in a quantity-based
listing approach or other waste minimization-based option.
The Agency also solicits comment on whether certain of the dye and
pigment wastestreams are better candidates for waste minimization, and
whether a waste minimization-based listing approach should target these
wastes. Finally, EPA requests comment on the testing and monitoring
needed to ensure proper implementation of a waste minimization listing
approach. Based on the comments the Agency receives on the above
issues, EPA may issue a supplemental proposal addressing a waste
minimization-based listing approach for the dyes and pigments industry.

IV. Applicability of the Land Disposal Restrictions Determinations

A. Request for Comment on the Agency's Approach to the Development of
BDAT Treatment Standards

RCRA requires EPA to make a land disposal prohibition determination
for any hazardous waste that is newly identified or listed in 40 CFR
part 261 after November 8, 1984, within six months of the date of
identification or final listing (RCRA Section 3004(g)(4), 42 U.S.C.
6924(g)(4)). EPA also is required to set ``* * * levels or methods of
treatment, if any, which substantially diminish the toxicity of the
waste or substantially reduce the likelihood of migration of hazardous
constituents from the waste so that short-term and long-term threats to
human health and the environment are minimized'' (RCRA Section
3004(m)(1), 42 U.S.C. 6924(m)(1)). Land disposal of wastes that meet
treatment standards thus established by EPA is not prohibited. The
wastes being proposed for listing in this action would be subject to
this requirement once a final rule is promulgated.
A general overview of the Agency's approach in performing analysis
of how to develop treatment standards for hazardous wastes can be found
in greater detail in Section III.A.1 of the preamble to the final rule
that set land disposal restrictions (LDR's) for the Third Third wastes
(55 FR 22535, June 1, 1990). The framework for the development of the
entire Land Disposal Restrictions program was promulgated November 7,
1986. (51 FR 40572).
While the Agency prefers source reduction/pollution prevention and
recycling/recovery over conventional treatment, inevitably, some wastes
(such as residues from recycling and inadvertent spill residues) will
be generated. Thus, standards based on treatment using ``best
demonstrated available technology'' (BDAT) will be required to be
developed for these wastes if a final rule listing them as hazardous is
promulgated.
Treatment standards typically are established based on the
performance data from the treatment of the listed waste or wastes with
similar chemical and physical characteristics or similar concentrations
of hazardous constituents. Treatment standards are established for both
wastewater and nonwastewater forms on a constituent-specific basis. The
constituents selected for regulation under the Land Disposal
Restrictions Program are not necessarily limited to those identified as
present in the listings proposed in this action, but include those
constituents or parameters that will ensure that the technologies are
operated properly.
Although data on waste characteristics and current management
practices for wastes proposed in this action have been gathered as part
of the administrative record for this rule, the Agency has not
completed its evaluation of the usefulness of these data for developing
specific treatment standards or assessing the capacity to treat (or
recycle) these wastes.
Some treatment technologies previously promulgated for newly
identified hazardous organic wastes are: chemical oxidation, wet air
oxidation, activated sludge, steam stripping, activated carbon, solvent
extraction, pyrolysis, thermal desorption, UV photolysis, ozonation,
and incineration. A current description of these technologies and what
types of wastes they are used to treat is available as a background
document and can be obtained by contacting NTIS (National Technical
Information Service, 5285 Port Royal Road, Springfield, VA 22161,
(703)487-4650) and requesting document PB91-160556, ``Treatment
Technology Document,'' L. Rosengrant, dated January, 1991, USEPA-OSW.
EPA intends to propose treatment standards for K162 through K166 in
a separate rulemaking. However, EPA specifically is soliciting comment
and data on the following as they pertain to the proposed listing of
dye and pigment industries wastes K162 through K166 as described in
this action:
(1) Technical descriptions of treatment systems that are or could
be used potentially for these wastes;
(2) Descriptions of alternative technologies that currently might
be available or anticipated as applicable;
(3) Performance data for the treatment of these or similar wastes
(in particular, constituent concentrations in both treated and
untreated wastes, as well as equipment design and operating
conditions);
(4) Information on known or perceived difficulties in analyzing
treatment residues or specific constituents;
(5) Quality assurance/quality control information for all data
submissions;
(6) Factors affecting on-site and off-site treatment capacity;
(7) Information on the potential costs for set-up and operation of
any current and alternative treatment technologies for these wastes;
(8) Information on waste minimization approaches.

B. Request for Comment on the Agency's Approach to the Capacity
Analyses in the LDR Program

In the land disposal restrictions determinations, the Agency must
demonstrate that adequate treatment or recovery capacity exists to
manage a newly listed waste with BDAT standards before it can restrict
the waste from further land disposal. The Agency performs capacity
analyses to determine if sufficient alternative treatment or recovery
capacity exists to accommodate the volumes of waste that will be
affected by the land disposal prohibition. If adequate capacity exists,
the waste must be treated to meet the BDAT standard before land
disposal. If adequate capacity does not exist, RCRA Section 3004(h)
authorizes EPA to grant a national capacity variance from the effective
date of the treatment standard for the waste for up to two years or
until adequate alternative treatment capacity becomes available,
whichever is sooner.
To perform capacity analyses, the Agency needs to determine the
volume of the listed waste that will require treatment prior to land
disposal. The volume of waste requiring treatment depends, in turn, on
the waste management practices employed by the listed waste generators.
Data on waste management practices for these wastes were collected
during the development of this proposed rule. However, as the
regulatory process proceeds, generators may decide to minimize or
recycle their wastes or otherwise alter their management practices.
Thus, EPA will update and monitor changes in management practices
because these changes will affect the final volume of waste requiring
commercial treatment capacity. Therefore, EPA needs information on
current and future waste management practices for these wastes,
including the volume of waste that are recycled, mixed with or co-
managed with other waste and discharged under Clean Water Act
provisions; and the volume and types of residuals that are generated by
various management practices applicable to newly listed and identified
wastes (e.g., treatment residuals).
The availability of commercial treatment capacity for these wastes
determines whether or not a waste is granted a capacity variance under
RCRA Section 3004(h). EPA continues to update and monitor changes in
available commercial treatment capacity because the commercial
hazardous waste management industry is extremely dynamic. For example,
national commercial treatment capacity changes as new facilities come
on-line, as new units and new technologies are added at existing
facilities, and as facilities expand existing units. The available
capacity at commercial facilities also changes as facilities change
their commercial status (e.g., changing from a fully commercial to a
limited commercial or captive facility). To determine the availability
of capacity for treating these wastes, the Agency needs to consider
currently available data, as well as the timing of any future changes
in available capacity.
For previous land disposal restriction rules, the Agency performed
capacity analyses using data from national surveys, including the 1987
National Survey of Hazardous Waste Treatment, Storage, Disposal, and
Recycling Facilities (the TSDR Survey) and the 1987 National Survey of
Hazardous Waste Generators (the Generator Survey). However, these
surveys cannot be used to determine the volumes of dye and pigment
wastes requiring treatment since these wastes were not included in the
surveys. Additionally, these surveys may not contain adequate
information on currently available capacity to treat newly identified
wastes because the data reflect 1986 capacity and do not include
facility expansions or closures that have occurred since then. Although
adjustments have been made to commercially available capacity to
account for changes in waste management through 1992, this was not done
on a consistent basis across all waste management practices.
EPA gathered data on waste generation, characteristics and
management practices for the listing determination of dye and pigment
wastes in the RCRA Section 3007 Questionnaire of 1991. The Agency has
compiled the capacity-related information from the survey responses and
is soliciting any updated or additional pertinent information.
To perform the necessary capacity analyses in the land disposal
restrictions rulemaking, the Agency needs reliable data on current
waste generation, waste management practices, available alternative
treatment capacity, and planned treatment capacity. The Agency will
need the annual generation volumes of waste by each waste code
including wastewater and nonwastewater forms, and soil or debris
contaminated with these wastes and the quantities stored, treated,
recycled, or disposed due to any change of management practices. EPA
also requests data from facilities capable of treating these wastes on
their current treatment capacity and any plans they may have in the
future to expand or reduce existing capacity. Specifically, the Agency
requests information on the determining factors involved in making
decisions to build new treatment capacity. Waste characteristics such
as pH level, BTUs, anionic character, total organic carbon content,
constituents concentration, and physical form also may limit the
availability of certain treatment technologies. For these reasons, the
Agency requests data and comments on waste characteristics that might
limit or preclude the use of any treatment technologies.

V. Compliance Dates

A. Notification

Under RCRA Section 3010, any person generating, transporting, or
managing a hazardous waste must notify EPA (or an authorized State) of
its activities. Section 3010(a) allows EPA to waive, under certain
circumstances, the notification requirement under Section 3010 of RCRA.
If these hazardous waste listings are promulgated, EPA is proposing to
waive the notification requirement as unnecessary for persons already
identified within the hazardous waste management universe (i.e.,
persons who have an EPA identification number under 40 CFR 262.12). EPA
is not proposing to waive the notification requirement for waste
handlers who have neither notified the Agency that they may manage
hazardous wastes nor received an EPA identification number. Such
individuals will have to provide notification under RCRA Section 3010.

B. Interim Status and Permitted Facilities

Because HSWA requirements are applicable in authorized States at
the same time as in unauthorized States, EPA will regulate EPA
Hazardous Wastes Nos. K162 through K166 until States are authorized to
regulate these wastes. Thus, once this regulation becomes effective as
a final rule, EPA will apply Federal regulations to these wastes and to
their management in both authorized and unauthorized States.

VI. State Authority

A. Applicability of Rule in Authorized States

Under Section 3006 of RCRA, EPA may authorize qualified States to
administer and enforce the RCRA program within the State. (See 40 CFR
part 271 for the standards and requirements for authorization.)
Following authorization, EPA retains enforcement authority under
Sections 3007, 3008, 3013, and 7003 of RCRA, although authorized States
have primary enforcement responsibility.
Before the Hazardous and Solid Waste Amendments of 1984 (HSWA)
amended RCRA, a State with final authorization administered its
hazardous waste program entirely in lieu of the Federal program in that
State. The Federal requirements no longer applied in the authorized
State, and EPA could not issue permits for any facilities located in
the State with permitting authorization. When new, more stringent
Federal requirements were promulgated or enacted, the State was
obligated to enact equivalent authority within specified time-frames.
New Federal requirements did not take effect in an authorized State
until the State adopted the requirements as State law.
By contrast, under Section 3006(g) of RCRA, 42 U.S.C. 6926(g), new
requirements and prohibitions imposed by the HSWA (including the
hazardous waste listings proposed in this notice) take effect in
authorized States at the same time that they take effect in non-
authorized States. EPA is directed to implement those requirements and
prohibitions in authorized States, including the issuance of permits,
until the State is granted authorization to do so. While States still
must adopt HSWA-related provisions as State law to retain final
authorization, the Federal HSWA requirements apply in authorized States
in the interim.

B. Effect on State Authorizations

Because this proposal (with the exception of the actions proposed
under CERCLA authority) will be promulgated pursuant to the HSWA, a
State submitting a program modification is able to apply to receive
either interim or final authorization under Section 3006(g)(2) or
3006(b), respectively, on the basis of requirements that are
substantially equivalent or equivalent to EPA's requirements. The
procedures and schedule for State program modifications under Section
3006(b) are described in 40 CFR 271.21. It should be noted that all
HSWA interim authorizations currently are scheduled to expire on
January 1, 2003 (see 57 FR 60129, February 18, 1992).
Section 271.21(e)(2) of EPA's state authorization regulations (40
CFR part 271) requires that States with final authorization modify
their programs to reflect Federal program changes and submit the
modifications to EPA for approval. The deadline by which the States
must modify their programs to adopt this proposed regulation, if it is
adopted as a final rule, will be determined by the date of promulgation
of a final rule in accordance with 40 CFR 271.21(e)(2). If the proposal
is adopted as a final rule, Table 1 at 40 CFR 271.1 will be amended
accordingly. Once EPA approves the modification, the State requirements
become RCRA Subtitle C requirements.
States with authorized RCRA programs already may have regulations
similar to those in this proposed rule. These State regulations have
not been assessed against the Federal regulations being proposed to
determine whether they meet the tests for authorization. Thus, a State
would not be authorized to implement these regulations as RCRA
requirements until State program modifications are submitted to EPA and
approved, pursuant to 40 CFR 271.21. Of course, States with existing
regulations that are more stringent than or broader in scope than
current Federal regulations may continue to administer and enforce
their regulations as a matter of State law.
It should be noted that authorized States are required to modify
their programs only when EPA promulgates Federal standards that are
more stringent or broader in scope than existing Federal standards.
Section 3009 of RCRA allows States to impose standards more stringent
than those in the Federal program. For those Federal program changes
that are less stringent or reduce the scope of the Federal program,
States are not required to modify their programs. See 40 CFR 271.21(e).
This proposed rule, if promulgated, would expand the scope of the
Federal program by adding additional listed wastes. Therefore, States
would be required to modify their programs to retain authorization to
implement and enforce these regulations.

VII. CERCLA Designation and Reportable Quantities

All hazardous wastes listed under RCRA and codified in 40 CFR
261.31 through 261.33, as well as any solid waste that exhibits one or
more of the characteristics of a RCRA hazardous waste (as defined in
Sections 261.21 through 261.24), are hazardous substances under the
Comprehensive Environmental Response, Compensation, and Liability Act
of 1980 (CERCLA), as amended. See CERCLA Section 101(14)(C). CERCLA
hazardous substances are listed in Table 302.4 at 40 CFR 302.4 along
with their reportable quantities (RQs). RQs are the minimum quantity of
a hazardous substance that, if released, must be reported to the
National Response Center (NRC) pursuant to CERCLA Section 103. In this
action, the Agency is proposing to list the proposed wastes in this
action as CERCLA hazardous substances in Table 302.4 of 40 CFR 302.4,
but is taking no action to adjust the one-pound statutory RQs for these
substances.
Reporting Requirements. Under Section 102(b) of CERCLA, all
hazardous substances newly designated under CERCLA will have a
statutory RQ of one pound unless and until adjusted by regulation.
Under CERCLA Section 103(a), the person in charge of a vessel or
facility from which a hazardous substance has been released in a
quantity that is equal to or exceeds its RQ immediately shall notify
the NRC of the release as soon as that person has knowledge thereof.
The toll-free number of the NRC is 1-800-424-8802; in the Washington,
DC metropolitan area, the number is (202) 426-2675. In addition to this
reporting requirement under CERCLA, Section 304 of the Emergency
Planning and Community Right-to-Know Act of 1986 (EPCRA) requires
owners or operators of certain facilities to report the release of a
CERCLA hazardous substance to State and local authorities. Immediately
after the release of a RQ or more, EPCRA Section 304 notification must
be given to the community emergency coordinator of the local emergency
planning committee for each area likely to be affected by the release,
and to the State emergency response commission of any State likely to
be affected by the release.
If this proposal is promulgated as a final rule, releases equal to
or greater than the one-pound statutory RQ will be subject to the
requirements described above, unless and until the Agency adjusts the
RQs for these substances in a future rulemaking.

VIII. Economic Impact Analysis

This section of the preamble summarizes the costs and benefits of
the dye and pigment hazardous waste listings. Based upon the EIA, the
Agency estimates that the listing of the five dye and pigment
production wastes discussed above may result in nationwide, pre-tax,
annualized costs of approximately $18.1 million for compliance in
commercial Subtitle C landfills. The possible future costs of this
listing including compliance with land disposal restrictions (LDRs)
range from $20.3 to $70.7 million per year. The $70.7 million
represents off-site incineration of non-wastewaters, while the $20.3
million assumes facilities with large non-wastewater waste volumes will
construct on-site incinerators. A complete discussion of the EIA is
available in the regulatory docket entitled ``Costs and Economic Impact
Analysis of Listing Hazardous Wastes from the Organic Dye and Pigment
Industries,'' November 28, 1994.

A. Compliance Costs for Listings

The remainder of this section briefly describes (1) the universe of
dye and pigment production facilities and volumes of the seven dye and
pigment production wastes proposed to be listed, (2) the methodology
for determining incremental cost and economic impacts to regulated
entities, (3) the potential remedial action costs, and (4) economic
impacts. Results of the analysis are summarized in Table VIII-1.
1. Universe of Dye and Pigment Production Facilities and Waste Volumes
In order to estimate costs for the EIA, it first was necessary to
estimate the total annual generation of dye and pigment production
wastes affected by this action. As described in Section II.B of this
preamble, the portion of the dye and pigment industry producing
products affected by this listing is composed of 33 manufacturers
operating 49 facilities producing dyes and pigments. In 1992, U.S.
sales of all organic dyes and pigments totalled 403 million lbs., with
a value of $1,691 million. Total annual product volumes and waste
quantities generated by these affected facilities were derived from a
1991 survey of the dye and pigment production industries. The
production volume and, hence, waste volume for dyes and pigments varies
year to year depending on which colors are popular. A season in which
dark colors are in fashion will produce higher volumes of waste; it is
not known which colors were predominant in the study year.
2. Method for Determining Cost and Economic Impacts
This section details EPA's approach for estimating the incremental
compliance cost and the economic impacts attributable to the listing of
dye and pigment production wastes. Because the dye and pigment
production industries are moderately small (33 manufacturers currently
operating 49 facilities), EPA was able to collect facility-specific
information and estimate incremental costs at the wastestream level.
For ten of the 49 facilities, however, some of the waste generation
data were missing. In these cases, waste generation amounts were
estimated. The information used in this analysis was collected in 1992
through RCRA Section 3007 Questionnaires, engineering site visits, and
sampling and analysis of wastestreams.

Approach to the Cost Analysis

EPA's approach to the cost analysis for this rule was to compare
the cost of current management practices, as reported in the RCRA
Section 3007 Questionnaire by dye and pigment production facilities,
with the projected cost of management to comply with the RCRA Subtitle
C hazardous waste program. An additional analysis included the future
cost to the industry of complying with land disposal restrictions. This
difference in cost, when annualized,\9\ represents the incremental
annual compliance costs attributable to the rule.
---------------------------------------------------------------------------

\9\Costs are discounted at a pre-tax rate of 4 percent over a
20-year period.
---------------------------------------------------------------------------

Baseline or Current Management Scenario

Relying on survey responses and engineering site visits, EPA was
able to determine the current (i.e., 1991) management practices for the
handling and disposal of dye and pigment production wastes. Current
management practices varied among facilities and wastestreams, and
included such practices as on-site monofilling, off-site incineration,
on-site destruction in boilers, and off-site landfilling in municipal,
industrial or Subtitle C landfills. These current management practices
at each facility represent the baseline scenario of the analysis.
As part of the survey, EPA asked each facility to identify current
costs for the management of dye and pigment production wastes. For this
analysis, EPA relied on the industry's own waste-specific estimates
concerning the cost of current management. EPA realizes that future
events, such as waste minimization efforts, may change waste generation
volumes and, thus, future waste management costs.

Post-Regulatory Management Scenarios

In estimating the cost of compliance with the listing of dye and
pigment production wastes as RCRA hazardous wastes, EPA assessed the
potential waste management on the part of industry to the listing and
also assessed the management cost in response to LDRs.
Initial waste management, excluding land disposal restrictions,
assumes all non-wastewaters will be sent to off-site Subtitle C
landfills. Wastewaters are assumed to be handled in tanks, at an
estimated cost of $18.1 million/yr. It is important to note that 81 to
95 percent of the total, annual, incremental compliance costs result
from listing the non-wastewaters. The non-wastewaters comprise less
than one percent of the quantity of the affected wastes.
There were two possible management strategies examined for the dye
and pigment industries following the promulgation of LDRs. The first
strategy, the higher-cost response, is waste management, including land
disposal restrictions, with all non-wastewaters being sent to off-site
incinerators. Wastewaters are assumed to be handled in newly-
constructed treatment impoundments, which makes this strategy an upper-
bound estimate ($70.7 million/yr) because the other option for
wastewaters, handling in tanks, is marginally less expensive.
The second strategy for waste management assumes facilities with
high waste volumes will construct on-site incinerators in which to
treat their non-wastewaters, with the remaining facilities sending
their wastes to off-site incinerators ($20.3 million/yr). Wastewaters
are assumed to be handled in newly constructed treatment impoundments.
3. Potential Remedial Action Costs
In addition to dye and pigment production wastes, this listing can
affect the management of soils, ground water, and other remedial
materials. The Agency's ``contained in'' policy defines certain
remediation wastes ``containing'' a listed hazardous waste as a RCRA
hazardous waste. It is possible that areas of past dye and pigment
waste management, spills, or disposal, which met the proposed listing
description at the time they were placed on the land, still may have
contaminant concentrations which exceed ``contained in'' levels. A
person who disturbs such material can become a generator of RCRA
hazardous waste. The likelihood of this imposing an additional burden
is moderate because at least 9 of the 49 dye and pigment production
facilities already are permitted TSDFs. Releases from all solid waste
management units at these TSDFs, including those that in the future may
be found to contain a waste meeting the dye and pigment listing
descriptions, already are covered by facility-wide clean-up rules under
40 CFR 264.101. This issue will be more likely to arise from historical
off-site management at facilities that were not TSDFs. The pre-tax,
incremental cost of corrective action liabilities has been estimated at
less than $8.8 million.

Table VIII-1.--Total, Incremental, Pre-tax, Annualized Social Costs for the Dye and Pigment Industry for the
Listing Action, and Land Disposal Restrictions Including Off-Site Incineration and On-Site Incineration by Each
Post-Regulatory Waste Code
----------------------------------------------------------------------------------------------------------------
Total annualized costs Total annualized costs
Total annualized costs for LDR off-site for LDR on-site
Waste code for listing\10\ ($ incineration\11\ ($ incineration\12\ ($
millions) millions) millions)
----------------------------------------------------------------------------------------------------------------
K162............................. 2.77 24.76 5.83
K163............................. 2.64 2.66 2.64
K164............................. 8.50 38.98 7.38
K165............................. 0.62 0.70 0.62
K166............................. 3.50 3.53 3.53
RCRA............................. 0.03 0.06 0.31
Total\13\.................. 18.05 70.69 20.31
----------------------------------------------------------------------------------------------------------------
\10\The listing estimate assumes non-wastewaters will be managed in Subtitle C landfill and wastewaters will be
handled in tanks.
\11\This upper-bound estimate assumes non-wastewaters are incinerated off-site and wastewaters are handled in
newly constructed treatment impoundments.
\12\This lower-bound estimate which includes LDRs assumes the construction of on-site incincerators for
facilities with non-wastewater volumes over 635 MT/yr. Wastewaters are handled in newly constructed treatment
impoundments.
\13\Numbers may not add due to rounding.

4. Economic Impacts
The following economic impacts potentially are overestimated as a
result of inconsistencies in the reporting in the RCRA Section 3007
Questionnaire responses. Some facilities were found to have reported
production quantities on a pure product basis while reporting the
average selling price per pound on a dilute product basis. This results
in an underestimation of revenues, as a result of reduced production
volumes, and an overestimation of economic impacts. In addition, some
of the volume of several of the wastestreams is for co-managed wastes.
The values of production for the co-generated products were not
available and, thus, further underestimated revenues which resulted in
overestimated economic impacts. Economic impacts were evaluated based
on incremental, annualized compliance costs discounted at an after-tax
rate of 7 percent over a 20-year period. Of the 49 facilities 9
facilities may incur potential ``significant economic impacts'' (i.e.,
bear compliance costs that would require product cost increases of at
least 5 percent) with one of these facilities facing product-line
discontinuation. Sixteen of the 49 facilities are estimated to incur
potential significant impacts assuming possible future costs for the
high-cost LDR alternative. Economic ratios indicate potential closure
or product-line discontinuation for 4 of the 16 significantly affected
facilities. Under the low-cost LDR alternative, 15 of the 49 facilities
are estimated to incur potential significant economic impacts. Two of
the 15 significantly affected facilities are estimated to incur closure
or product-line discontinuation.
5. Benefits of Listings
One objective of a population analysis is to estimate the number of
cancer cases that could be avoided as a result of the implementation of
the proposed rule. People drinking contaminated water from residential
wells located near the source of contamination, people eating home-
grown vegetables contaminated by blowing dust or vapors, and people
breathing air contaminated by a disposal unit are the potentially
exposed population for this rule. The Agency did not estimate the
population risks from current practices or the incremental risk
reduction from future actions as a result of the proposed regulation;
however, preliminary analysis suggests that the incremental risk in
terms of cancer cases avoided is expected to be near zero.
One benefit associated with this rulemaking is to place
wastestreams the Agency has determined could pose a risk to human
health and the environment into the hazardous waste management system.
When wastestreams are placed in this system, the risk associated with
their disposal is minimized by the requirements of this system.
The Agency, however, has historical information that shows damage
to ground water and other sensitive environments has occurred during
the management of wastes from the dye and pigment manufacturing
operations. At ten dye and pigment facilities, the quality of ground
water has been adversely affected by waste management activities,
typically unlined waste trenches, aeration basins, and impoundments.
One dye company had to purchase the deeds to three nearby residences
and a gas station because VOC-contaminated ground water originating
from the plant had contaminated surrounding drinking water wells. At
another dye facility, a contaminated ground-water plume migrated under
residential houses bordering the site. The residential wells, used for
swimming pools and irrigation systems in the neighborhood, were
condemned because of chemical contamination. Ground water was
contaminated from land treatment of dye wastewater being sprayed onto a
field, and passing through a layer of clay. Soil contamination near
drum storage pads or drum wash areas has been documented at 7 dye
facilities. As a result, the leachate from these soils possibly
contributed to the ground- water contamination associated with many of
the sites. Concentrations of volatile and semi-volatile organic
compounds have been found in soils surrounding an on-site landfill at a
dye facility. Finally, dye and pigment facilities are found on the
Superfund National Priority List; further evidence that mismanagement
of dye and pigment wastes have the potential to yield threats of
concern to human health. In summary, although difficult to quantify
precisely, a benefit of today's proposal is the prevention of
additional or similar incidents occurring from similar management
practices of dye and pigment wastes that potentially could degrade the
quality of ground water or other sensitive natural resources.
In addition to the reduction of human health risk associated with
the mismanagement of dye and pigment wastes proposed for listing in
this rulemaking, there are a number of other benefits that are even
more difficult to quantify.
The Subtitle C management framework for generators and permitted
treatment storage and disposal facilities establishes standards for
hazardous waste handling, management, and remediation that: Reduce
ecological risks, reduce natural resource damage, reduce the likelihood
and severity of accidents, improve worker safety, promote facility-wide
remedial programs, insure that adequate financial assurance is
established to handle protective closure of waste management units,
increase public participation, improve information availability on
waste quantity and movement, ensure minimum uniform national standards,
and create incentives for pollution prevention.

Ecological and Natural Resource Damage Reduction

The risk assessment for this listing has focused on the human
health risks associated with plausible management of dye and pigment
wastes. An additional concern, given the proximity of several
facilities to surface waters and their associated wetland systems, is
the potential for ecological damages to biota inhabiting surface waters
and wetlands. In some cases migration to the surface water may be
occurring via groundwater. EPA requests comments regarding the
potential for ecological damages associated with the wastes proposed
for listing in today's rulemaking.
In addition to direct ecological and human health damage there is
evidence from EPA's contaminant fate and transport modelling and case
studies of ground water, surface water, and soil degradation. While use
of and human exposure to these natural resources may not be occurring
now, their use in the future could be limited if they are contaminated.
The Subtitle C waste management program will limit future releases and
prevent natural resource damages. These benefits have not been
quantified.

Reduce the Likelihood and Severity of Accidents

An important component of the Subtitle C system for both generators
and permitted treatment, storage and disposal facilities is the need to
establish waste analysis plans, contingency plans, emergency
procedures, inspection programs, construction quality assurance and
personnel training programs. In addition, permitted facilities also
must have in place inspection programs and location standards. The
costs of these programs have been included in the cost analysis, but
the benefits are difficult to quantify. These Subtitle C programs may
reduce risk to workers and nearby populations by reducing the chance of
contaminant releases, accidental exposures, and catastrophic failures.
In the event that accidents occur, these Subtitle C provisions increase
the likelihood of quick action and ensure protection of human health
and the environment. There are other programs that require similar
planning (e.g., OSHA, Section 112(r) of the Clean Air Act) and
indirectly affect hazardous waste handling; RCRA regulatory provisions
deal directly with accident prevention standards associated with the
handling of hazardous wastes.

Promote Facility-Wide Remedial Programs

Those facilities that choose to obtain Part B permits for the
treatment, storage and disposal of hazardous wastes will have the
responsibility of ensuring that adequate corrective action programs are
in place to control releases from all solid waste management units. The
cost analysis included an evaluation of the cost of facility-wide
corrective action while the risk assessment focused only on the risks
associated with hazardous waste management units. Although difficult to
quantify, there are risk-reduction benefits associated with the cleanup
of releases from the solid waste management units in addition to those
benefits associated with the handling of listed waste.

Financial Assurance To Insure Protective Closure of Waste Management
Units

Permitted facilities are required to support financial mechanisms
which ensure that adequate funds are available to close hazardous waste
treatment, storage and disposal units in a manner that ensures long-
term protection of human health and the environment. The costs of those
financial assurance requirements have been included in the cost
analysis; however, the benefits are difficult to quantify. Financial
assurance has the benefit of insuring that owners and operators of
hazardous waste facilities have sufficient financial resources to close
their facilities in an environmentally-protective manner.

Increase Public Participation and Improve Information Availability

The Subtitle C system has the benefit of providing the information
needed to empower local communities and waste managers, those most
affected by and able to improve substandard waste management practices.
The public participation provisions of the Subtitle C system ensure
that information is provided to stakeholders regarding the risks to
human health and the environment of a new or expanding waste management
facility. Biennial reporting, required of all large quantity generators
of hazardous waste, allows for more informed waste management decisions
and capacity management. Finally, the manifest system, which is used to
track the movement of wastes, ensures protective handling of hazardous
wastes as they move in commerce.

IX. Executive Order 12866

Executive Order 12866 requires that regulatory agencies determine
whether a new regulation constitutes a significant regulatory action. A
significant regulatory action is defined as an action likely to result
in a rule that may:
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;
Create a serious inconsistency or otherwise interfere with
an action taken or planned by another agency;
Materially alter the budgetary impact of entitlements,
grants, user fees, or loan programs or rights and obligations of
recipients thereof; or
Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
Executive Order 12866.
EPA estimated the costs of the proposed listings and evaluated the
other factors above to determine if this proposed rule making would be
a major regulation as defined by the Executive Order. Today's proposed
rule is estimated to have an annualized incremental cost of less than
$19 million. Based on EPA's analysis of the other factors, today's
proposed rule is considered a significant regulatory action because of
the novel policy issues contained herein. As a significant regulatory
action, it has been submitted to and reviewed by the Office of
Management and Budget.

X. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) of 1980 requires Federal
agencies to consider ``small entities'' throughout the regulatory
process. Section 603 of the RFA requires an initial screening analysis
to be performed to determine whether small entities will be affected by
the regulation. If affected small entities are identified, regulatory
alternatives that mitigate the potential impacts must be considered.
Small entities as described in the Act are only those ``businesses,
organizations and governmental jurisdictions subject to regulation.''
For SIC 2865, Cyclic Crudes and Intermediates, the Small Business
Administration defines small entities as those firms employing less
than or equal to 750 employees. Based on this employment cutoff,
approximately 61 percent, or 20 of the 33 affected dye and/or pigment
manufacturers (i.e., companies) are considered small entities. Under
the listing alternative, which assumes disposal of wastewater treatment
sludges/solids in an off-site commercial Subtitle C landfill and
management of wastewaters in tanks, 7 of the 33 affected companies are
estimated to incur potential significant economic impacts. Four of the
7 companies estimated to incur potential significant economic impacts
are small entities. Although small entities are predominant in the
affected industry, the proposed listings do not adversely affect small
entities to a greater extent than large entities.
Under the Agency's Revised Guidelines for Implementing the
Regulatory Flexibility Act, the Agency is committed to considering
regulatory alternatives in rulemakings when there are any estimated
economic impacts on small entities. The Agency obtained firm level
employment data for the purpose of identifying and evaluating economic
impacts on small entities. The statutory requirements of the RCRA
program do not provide legal avenues to grant relief from the proposed
listings to small entities. Because of statutory restrictions, the
Agency is unable to exempt small entities or develop options to reduce
economic impacts on small entities. The Agency must identify waste
streams for listing without regard to the size of the entity being
regulated. However, the possibility of enforceable agreements described
previously may ameliorate the impact of listing on small entities.

XI. Paperwork Reduction Act

This rule does not contain any new information collection
requirements subject to OMB review under the Paperwork Reduction Act of
1980, 44 U.S.C. 3501 et seq. Facilities will have to comply with the
existing Subtitle C record keeping and reporting requirements for the
newly listed wastestreams.
To the extent that this rule imposes any information collection
requirements under existing RCRA regulations promulgated in previous
rule makings, those requirements have been approved by the Office of
Management and Budget (OMB) under the Paperwork Reduction Act, 44
U.S.C. 3501 et seq., and have been assigned OMB control numbers 2050-
120 (ICR no. 1573, Part B Permit Application); 2050-120 (ICR 1571,
General Facility Standards); 2050-0028 (ICR 261, Notification to Obtain
an EPA ID); 2050-0034 (ICR 262, Part A Permit Application); 2050-0039
(ICR 801, Hazardous Waste Manifest); 2050-0035 (ICR 820, Generator
Standards); and 2050-0024 (ICR 976, Biennial Report).
Release reporting required as a result of listing wastes as
hazardous substances under CERCLA and adjusting the reportable
quantities (RQs) has been approved under the provisions of the
Paperwork Reduction Act, 44 U.S.C. 3501 et seq., and has been assigned
OMB control number 2050-0046 (ICR 1049, Notification of Episodic
Release of Oil and Hazardous Substances).

List of Subjects

40 CFR Part 261

Environmental protection, Hazardous materials, Waste treatment and
disposal, Recycling.

40 CFR Part 271

Environmental protection, Administrative practice and procedure,
Confidential business information, Hazardous material transportation,
Hazardous waste, Indians-lands, Intergovernmental relations, Penalties,
Reporting and recordkeeping requirements, Water pollution control,
Water supply.

40 CFR Part 302

Environmental protection, Air pollution control, Chemicals,
Emergency Planning and Community Right-to-Know Act, Extremely hazardous
substances, Hazardous chemicals, Hazardous materials, Hazardous
materials transportation, Hazardous substances, Hazardous wastes,
Intergovernmental relations, Natural resources, Pesticides and pests,
Reporting and recordkeeping requirements, Superfund, Waste treatment
and disposal, Water pollution control, Water supply.

Dated: December 5, 1994.
Carol M. Browner,
Administrator.

For the reasons set out in the preamble, it is proposed to amend
title 40 of the Code of Federal Regulations as follows:

PART 261--IDENTIFICATION AND LISTING OF HAZARDOUS WASTE

1. The authority citation for Part 261 continues to read as
follows:

Authority: 42 U.S.C. 6905, 6912(a), 6921, 6922, and 6938.
2. In Sec. 261.32, the table is amended by adding the subgroup
``Organic dyes and pigments,'' and adding to this subgroup the
following wastestreams:

Sec. 261.32 Hazardous wastes from specific sources.

* * * * *

------------------------------------------------------------------------
Industry and EPA Hazard
hazardous waste No. Hazardous waste code
------------------------------------------------------------------------

* * * * * * *
Organic dyes and
pigments:

* * * * * * *
K162................ Wastewater treatment sludge from the (T)
production of azo pigments.
K163................ Wastewaters from the production of azo (T)
pigments.
K164................ Wastewater treatment sludge from the (T)
production of azo dyes, excluding FD&C
colorants.
K165................ Wastewaters from the production of azo (T)
dyes, excluding FD&C colorants.
K166................ Still bottoms or heavy ends from the (T)
production of triarylmethane dyes or
pigments.

* * * * * * *
------------------------------------------------------------------------

Appendix VII to Part 261 [Amended]

3. Appendix VII to Part 261 is amended by adding the following
wastestreams in alphanumeric order (by the first column) to read as
follows:

Appendix VII--Basis For Listing Hazardous Waste
------------------------------------------------------------------------
EPA hazardous waste No. Hazardous constituents for which listed
------------------------------------------------------------------------

* * * * * * *
K162..................... Aniline, 2-aminoaniline, 4-aminoaniline, 2-
methoxyaniline, 2-aminotoluene, 4-
aminotoluene, acetoacet-o-anisidide,
acetoacet-o-toluidide, acetoacetanilide, 1,3-
dinitrobenzene, 3,3'dimethylbenzidine,
nitrobenzene, 2,4-dinitrophenol.
K163..................... 2-aminoaniline, 4-aminoaniline, 2-
methoxyaniline, 2-aminotoluene, 3-
aminotoluene, 4-aminotoluene, aniline,
acetoacet-o-anisidide, acetoacet-o-
toluidide, acetoacetanilide, 2,4-
dimethylaniline, 2,6-dimethylaniline.
K164..................... 2-aminoaniline, 4-aminoaniline, 2-
methoxyaniline, aniline, diphenylamine, N-
nitrosodiphenylamine, 3,3'-
dimethoxybenzidine, 4-methylphenol, 1,3-
dinitrobenzene, 2-methoxy-5-nitroaniline,
2,4-dinitrophenol, 2-aminotoluene, 4-
aminotoluene.
K165..................... 2-aminoaniline, 4-aminoaniline, 2-
methoxyaniline, 2-aminotoluene, 3-
aminotoluene, 4-aminotoluene, aniline.
K166..................... 1,2-diphenylhydrazine, azobenzene, aniline,
diphenylamine, N-nitrosodiphenylamine.

* * * * * * *
------------------------------------------------------------------------

Appendix VIII to Part 261 [Amended]

4. Appendix VIII to Part 261 is amended by adding the following
hazardous constituents in alphabetical order to read as follows:

----------------------------------------------------------------------------------------------------------------
Chemical
Common name Chemical abstracts name abstracts Hazardous
No. waste No.
----------------------------------------------------------------------------------------------------------------

* * * * * * *
Acetoacetanilide......................... Butanamide, 3-oxo-N-phenyl-.............. 102-01-2 .............
Acetoacet-o-anisidide.................... Butanamide, N-(2-methoxyphenyl)-3-....... 92-15-9 .............
Acetoacet-o-toluidide.................... Butanamide, N-(2-methylphenyl)-3-oxo-.... 93-68-5 .............

* * * * * * *
2-Aminoaniline........................... Benzenediamine, 1,2-..................... 95-54-5 .............
4-Aminoaniline........................... Benzenediamine, 1,4-..................... 106-50-3 .............

* * * * * * *
3-Aminotoluene........................... Benzenamine, 3-methyl-................... 108-44-1 .............

* * * * * * *
Azobenzene............................... Azobenzene............................... 103-33-3 .............

* * * * * * *
2,4-Dimethylaniline...................... Benzenamine, 2,4-dimethyl-............... 95-68-1 .............
2,6-Dimethylaniline...................... Benzenamine, 2,6-dimethyl-............... 87-62-7 .............

* * * * * * *
1,3-Dinitrobenzene....................... Benezene, 1,3-dinitro-................... 99-65-0 .............

* * * * * * *
2-Methoxyaniline......................... Benzenamine, 2-methoxy-.................. 90-04-0 .............

* * * * * * *
2-Methoxy-5-nitroaniline................. Benzenamine, 2-methoxy-5-nitro........... 99-59-2 .............

* * * * * * *
4-Methylphenol........................... Phenol, 4-methyl-........................ 106-44-5 .............

* * * * * * *
N-Nitrosodiphenylamine................... N-Nitrosodiphenylamine................... 86-30-6 .............

* * * * * * *
----------------------------------------------------------------------------------------------------------------

* * * * *

PART 271--REQUIREMENTS FOR AUTHORIZATION OF STATE HAZARDOUS WASTE
PROGRAMS

5. The authority citation for Part 271 continues to read as
follows:

Authority: 42 U.S.C. 6905, 6912(a), and 6926.

6. Section 271.1(j) is amended by adding the following entry to
Table 1 in chronological order by date of publication to read as
follows.

Sec. 271.1 Purpose and scope.

* * * * *
(j) * * *

Table 1--Regulations Implementing the Hazardous and Solid Waste Amendments of 1984
----------------------------------------------------------------------------------------------------------------
Promulgation date Title of regulation Federal Register reference Effective date
----------------------------------------------------------------------------------------------------------------

* * * * * * *
December 22, 1994.......... Listing Wastes from the [Insert Federal Register [Insert effective date].
Production of Dyes and page in numbers].
Pigments.

* * * * * * *
----------------------------------------------------------------------------------------------------------------

PART 302--DESIGNATION, REPORTABLE QUANTITIES, AND NOTIFICATION

7. The authority citation for Part 302 continues to read as
follows:

Authority: 42 U.S.C. 9602, 9603, and 9604; 33 U.S.C. 1321 and
1361.

Sec. 302.4 [Amended]

8. Section 302.4 is amended by adding the following entries to
Table 302.4 to read as follows. The appropriate footnotes to Table
302.4 are republished without change.
* * * * *

Table 302.4.--List of Hazardous Substances and Reportable Quantities
----------------------------------------------------------------------------------------------------------------
Statutory Final RQ
----------------------------------------------------
Hazardous substance CASRN Regulatory RCRA
synonyms RQ Code+ Waste Category Pounds (Kg)
No.
----------------------------------------------------------------------------------------------------------------

* * * * * * *
K162Wastewater treatment sludge from
the production of azo pigments...... ....... ........... 1* 4 K162
K163Wastewaters from the production
of azo pigments..................... ....... ........... 1* 4 K163
K164Wastewater treatment sludge from
the production of azo dyes,
excluding FD&C colorants............ ....... ........... 1* 4 K164
K165Wastewaters from the production
of azo dyes, excluding FD&C
colorants........................... ....... ........... 1* 4 K165
K166Still bottoms or heavy ends from
the production of triarylmethane
dyes or pigments.................... ....... ........... 1* 4 K168

* * * * * * *
----------------------------------------------------------------------------------------------------------------
+--Indicates the statutory source as defined by 1, 2, 3, and 4 below.
4--Indicates that the statutory source for designation of this hazardous substance under CERCLA is RCRA Section
3001.
1*--Indicates that the 1 pound RQ is a CERCLA statutory RQ.

[FR Doc. 94-30767 Filed 12-21-94; 8:45 am]
BILLING CODE 6560-50-P}}}}}}}}}}}}}