[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

 
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

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\
---------------------------------------------------------------------------

    \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.
---------------------------------------------------------------------------

    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                                                                                                                                    
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                   e                                                                                                                                    
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                   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.                                                       
                                                                                                                                                        
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 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]
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