Hazardous Waste Management System; Identification and Listing of
Hazardous Waste; Paint Production Wastes; Land Disposal Restrictions
for Newly Identified Wastes; CERCLA Hazardous Substance Designation and
Reportable Quantities; Designation of n-Butyl Alcohol, Ethyl Benzene,
Methyl Isobutyl Ketone, Styrene, and Xylenes as Appendix VIII
Constituents; Addition of Acrylamide and Styrene to the Treatment
Standards of F039; and Designation of Styrene as an Underlying
Hazardous Constituent
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
[Federal Register: February 13, 2001 (Volume 66, Number 30)]
[Proposed Rules]
[Page 10059-10140]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr13fe01-31]
[[Page 10059]]
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Part II
Environmental Protection Agency
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40 CFR Parts 148, et al.
Hazardous Waste Management System; Identification and Listing of
Hazardous Waste; Paint Production Wastes; Proposed Rule
[[Page 10060]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 148, 261, 268, 271, and 302
[SWH-FRL-6940-6]
RIN 2050-AE32
Hazardous Waste Management System; Identification and Listing of
Hazardous Waste; Paint Production Wastes; Land Disposal Restrictions
for Newly Identified Wastes; CERCLA Hazardous Substance Designation and
Reportable Quantities; Designation of n-Butyl Alcohol, Ethyl Benzene,
Methyl Isobutyl Ketone, Styrene, and Xylenes as Appendix VIII
Constituents; Addition of Acrylamide and Styrene to the Treatment
Standards of F039; and Designation of Styrene as an Underlying
Hazardous Constituent
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The EPA proposes to amend the regulations for hazardous waste
management under the Resource Conservation and Recovery Act (RCRA) by
listing as hazardous certain waste solids and liquids generated from
the production of paint. EPA is proposing a concentration-based listing
approach for each of these wastes. Under this approach, the identified
paint production wastes are hazardous if they contain any of the
constituents of concern at concentrations that meet or exceed
regulatory levels. Generators must determine whether their wastes are
listed hazardous wastes. If their wastes are below regulatory levels
for all constituents of concern, then their wastes are nonhazardous. We
are also proposing a contingent management option for waste liquids.
These wastes would not be subject to the listing if they are stored or
treated exclusively in tanks or containers prior to discharge to a
publicly owned treatment works or discharged under a Clean Water Act
national pollutant discharge elimination system permit. This proposal
would also add the toxic constituents n-butyl alcohol, ethyl benzene,
methyl isobutyl ketone, styrene, and xylenes found in these identified
wastes to the list of constituents that serves as the basis for
classifying wastes as hazardous, and to establish treatment standards
for the wastes. Due to the uncertainties in our assessment of the
management of paint manufacturing waste liquids in surface
impoundments, we are also considering an alternative proposal not to
list paint manufacturing waste liquids.
If these paint production wastes are listed as hazardous waste,
then they will be subject to stringent management and treatment
standards under Subtitle C of RCRA. Additionally, this action proposes
to designate these wastes as hazardous substances subject to the
Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) and to adjust the one pound statutory reportable quantities
(RQs) for these substances. Other actions proposed in this notice would
add acrylamide and styrene to the treatment standards applicable to
multisource leachate and designate styrene as an underlying hazardous
constituent. As a result, a single waste code would continue to be
applicable to multisource landfill leachates and residues of
characteristic wastes would require treatment when styrene is present
above the proposed land disposal standards.
DATES: EPA will accept public comments on this proposed rule until
April 16, 2001. 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 February 27, 2001.
ADDRESSES: If you would like to file a request for a public hearing on
this proposal, please submit your request to Mr. David Bussard at:
Office of Solid Waste, Hazardous Waste Identification Division (5304W),
U.S. Environmental Protection Agency, 1200 Pennsylvania Avenue, NW.,
Washington, DC 20460, (703) 308-8880.
If you wish to comment on this proposed rule, you must send an
original and two copies of the comments referencing docket number F-
2001-PMLP-FFFFF to: RCRA Docket Information Center, Office of Solid
Waste (5305G), U.S. Environmental Protection Agency Headquarters (EPA,
HQ), 1200 Pennsylvania Avenue, NW., Washington, DC 20460. Hand
deliveries of comments should be made to the RCRA Information Center
(RIC) located at Crystal Gateway, First Floor, 1235 Jefferson Davis
Highway, Arlington, VA. You also may submit comments electronically by
sending electronic mail through the Internet to: rcradocket@epa.gov.
See the beginning of the Supplementary Information section for
information on how to submit your comments as well as view public
comments and supporting materials.
Please do not submit any confidential business information (CBI)
electronically. You must submit an original and two copies of CBI under
separate cover to: RCRA CBI Document Control Officer, Office of Solid
Waste (5305W), U.S. EPA, 1200 Pennsylvania Avenue, NW., Washington, DC
20460.
FOR FURTHER INFORMATION CONTACT: For general information, contact the
RCRA Hotline at (800) 424-9346 or TDD (800) 553-7672 (hearing
impaired). In the Washington, DC, metropolitan area, call (703) 412-
9810 or TDD (703) 412-3323. For information on specific aspects of the
rule, contact Ms. Patricia Cohn or Mr. David Carver of the Office of
Solid Waste (5304W), U.S. Environmental Protection Agency, 1200
Pennsylvania Avenue, NW., Washington, DC 20460, (E-mail addresses and
telephone numbers: cohn.patricia@epa.gov (703-308-8675);
carver.david@epa.gov (703-308-8603)). For technical information on the
CERCLA aspects of this rule, contact Ms. Lynn Beasley, Office of
Emergency and Remedial Response, Analytical Operations and Data Quality
Center (5204G), U.S. Environmental Protection Agency, 1200 Pennsylvania
Avenue, NW., Washington, DC 20460, [E-mail address and telephone
number: beasley.lynn@epa.gov (703-603-9086)].
SUPPLEMENTARY INFORMATION:
How Do I Submit Comments to This Proposed Rule?
We are asking prospective commenters to voluntarily submit one
additional copy of their comments on labeled personal computer
diskettes in ASCII (text) format or a word processing format that can
be converted to ASCII (text). Specify on the disk label the word
processing software and version/edition as well as the commenter's
name. This will allow us to convert the comments into one of the word
processing formats used by the Agency. Please use mailing envelopes
designed to physically protect the submitted diskettes. We emphasize
that submission of comments on diskettes is not mandatory, nor will it
result in any advantage or disadvantage to any commenter.
If you submit comments electronically, identify comments in
electronic format with the docket number F-2001-PMLP-FFFFF. You must
submit all electronic comments as an ASCII (text) file, avoiding the
use of special characters and any form of encryption.
How Can I View Supporting Documents for This Proposed Rule?
You may view either the paper or electronic form of public comments
and supporting materials accompanying today's proposal. You may access
the paper copies of these supporting
[[Page 10061]]
documents in the RIC (See ADDRESSES section for address). The RIC is
open from 9 am to 4 pm, Monday through Friday, excluding Federal
holidays. To review docket materials, we recommend that you make an
appointment by calling (703) 603-9230. You may copy a maximum of 100
pages from any regulatory docket at no charge. Additional copies cost
$0.15/page.
You may also view these documents electronically on the Internet:
http://www.epa.gov/epaoswer/hazwaste/id/paint.
We will keep the official record for this action in paper form.
Accordingly, we will transfer all comments received electronically into
paper form and place them in the official record, which will also
include all comments submitted directly in writing. The official record
is the paper record maintained at the address under ADDRESSES at the
beginning of this document.
EPA responses to comments, whether the comments are written or
electronic, will be in a notice in the Federal Register or in a
response to comments document placed in the official record for this
rulemaking. We may, however, seek clarification of electronic comments
that become garbled in transmission or during conversion to paper form,
as discussed above.
Customer Service
How Can I Influence EPA's Thinking on this Proposed Rule?
In developing this proposal, we tried to address the concerns of
all our stakeholders. Your comments will help us improve this rule. We
invite you to provide views on options we propose, new data,
information on how this rule may affect you, or other relevant
information. We welcome your views on all aspects of this proposed
rule, but we particularly request comments on the items identified at
the end of each section. Your comments will be most effective if you
follow the suggestions below:
Include your name, the date, and the docket number with
your comments. Remember that your comments must be submitted by the
deadline specified in this notice.
Reference your comments to specific sections of the
proposal by using section titles, page numbers of the preamble, or the
regulatory citations.
Clearly label any confidential business information (CBI)
submitted as part of your comments.
Explain your views as clearly as possible and provide a
summary of the reasoning you used to arrive at your conclusions as well
as examples to illustrate your views where possible.
Tell us which parts of this proposal you support, as well
as those with which you disagree.
Offer specific alternatives.
Provide solid technical data to support your views. For
example, if you estimate potential costs, explain how you arrived at
your estimate.
Contents of This Proposed Rule
I. Overview
A. Who Potentially Will Be Affected by This Proposed Rule?
B. What Impact May This Proposed Rule Have?
C. Why Does This Proposed Rule Read Differently from Other
Listing Rules?
D. What Are The Statutory Authorities for This Proposed Rule?
II. Background
A. How Does EPA Define a Hazardous Waste?
B. How Does EPA Regulate RCRA Hazardous Wastes?
C. How Does EPA Regulate Solid Wastes That Are Not RCRA
Hazardous Wastes?
D. Overview of The Hazardous Waste Listing Determination Process
for Paint Production Wastes
1. Suspension of Previous Listings
2. Consent Decree Schedule for This Proposal
E. Existing Regulations That Apply to This Industry
F. What Industries and Wastes Are Covered in This Proposed Rule?
1. Scope of Consent Decree
2. Scope of Listing: Off-Specification Products
3. Recycling Issues
G. Description of The Paint and Coatings Industry
H. What Information Did EPA Collect and Use?
1. Site Visits
2. DataBase of Paint Manufacturing Information from Published
Sources
3. The RCRA Section 3007 Survey
a. Overview
b. Structuring The Survey to Capture All The Wastes of Concern
c. Identifying The Universe of Paint Manufacturing Facilities
d. Constructing a Stratified Random Sample
e. Conducting The Survey and Analyzing The Results
f. Meeting Our Objectives for The Survey
III. Approach Used in This Proposed Listing
A. Summary of Today's Action
B. What Is a Concentration-Based Listing?
C. Why Is a Concentration-Based Approach Being Used for This
Listing?
D. How Did The Agency Use The Survey Results for This Proposed
Listing Determination?
1. General Assessment of The Paint Industry's Waste Generation
and Management Practices
2. Management Scenarios Currently Used at Paint Facilities and
Our Selection of Waste Management Scenarios for Risk Assessment
Modeling
a. Plausible Waste Management Selection Criteria and Modeling
Considerations
b. Selection of Waste Management Scenarios for Risk Assessment
Modeling of Nonhazardous Paint Manufacturing Waste Solids
c. Selection of Waste Management Scenarios for Risk Assessment
Modeling of Nonhazardous Paint Manufacturing Waste Liquids
d. Survey Data as Input to Modeling Parameters
E. What Risk Assessment Approach Did EPA Use to Determine
Allowable Constituent Waste Concentrations?
1. Which Factors Did EPA Incorporate Into Its Quantitative Risk
Assessment?
2. How Did EPA Use Damage Case Information?
3. Overview of The Risk Assessment
4. How EPA Chose Potential Constituents of Concern
a. Phase 1: How Did EPA Develop a Preliminary List of
Constituents?
b. Phase 2: How Did EPA Select Potential Constituents of Concern
for The Risk Assessment?
c. Phase 3: How Did EPA Choose Additional Constituents for The
Risk Assessment?
5. What Was EPA's Approach to Conducting Human Health Risk
Assessment?
a. What Waste Management Scenarios Were Evaluated?
b. What Exposure Scenarios Did EPA Evaluate?
c. How Did EPA Quantify Each Receptor's Exposure to
Contaminants?
d. How Did EPA Predict The Release and Transport of Constituents
From a Waste Management Unit to Receptor Locations?
e. What Is The Human Health Toxicity of COC's Identified by EPA?
f. What Are The Results From The Risk Assessment?
g. What Is The Uncertainty in Human Health Risk Results?
6. What Was EPA's Approach to Conducting The Ecological Risk
Assessment?
a. How Were Ecological Exposures Estimated?
b. What Ecological Receptors Did The EPA Evaluate?
c. How Did EPA Consider The Toxicity of Constituents in The
Ecological Risk Assessment?
7. Did EPA Conduct a Peer Review of The Risk Assessment?
IV. Proposed Listing Determinations and Regulations
A. What Are The Proposed Regulations for Paint Production
Wastes?
B. Why Are We Proposing to Use The Level of Constituents in The
Waste Solids as Total Waste Concentrations Rather Than Leachate
Concentrations?
C. Why Are We Proposing to Exclude Waste Liquids Managed in
Tanks?
1. On-Site Storage and Treatment Tanks
2. Management of Liquid Paint Manufacturing Wastes in Off-Site
Treatment Tanks
D. Why Are We Proposing a Contingent Management Listing for
Liquid Paint Manufacturing Wastes, and What Other Options Are We
Considering?
[[Page 10062]]
E. Potential for Formation of Non-Aqueous Phase Liquids in Paint
Manufacturing Wastes
F. Scope of The Listings and The Effect on Treatment Residuals
G. Relationships of The Proposed Listings to The TC
H. What Is The Status of Landfill Leachate from Previously
Disposed Wastes?
V. Proposed Generator Requirements for Implementation of
Concentration-Based Listings
A. Would I Have to Determine Whether or Not My Wastes Are
Hazardous?
B. How Would I Manage My Wastes During The Period Between The
Effective Date of The Final Rule and Initial Hazardous Waste
Determination for My Wastes?
C. What Procedures Would I Follow to Determine If My Wastes Are
Nonhazardous?
1. Testing Wastes
2. Using Knowledge of The Wastes
D. How Would The Proposed Contingent Management Listing for
Liquid Wastes Be Implemented?
E. What Records Would I Need to Keep On-site to Support a
Nonhazardous Determination for My Wastes?
F. What Would Happen if I Do Not Meet The Recordkeeping
Requirements for The Wastes That I Have Determined Are Nonhazardous?
G. Could I Treat My Wastes to Below Listing Concentrations and
Then Determine That My Wastes Are Nonhazardous?
1. Paint Manufacturing Waste Solids
2. Paint Manufacturing Waste Liquids
VI. Proposed Treatment Standards Under RCRA's Land Disposal
Restrictions (LDRs)
A. What are EPA's LDRs?
B. How Does EPA Develop LDR Treatment Standards?
C. What Treatment Standards Are Proposed?
D. Other LDR-Related Provisions
1. F039 Multisource Leachate and Universal Treatment Standards
E. Is There Treatment and Management Capacity Available for
These Proposed Newly Identified Wastes?
1. What Is a Capacity Determination?
2. What Are The Capacity Analysis Results?
3. What Is The Available Treatment Capacity for Other Wastes
Subject to Revised UTS and F039 Standards?
VII. State Authority and Compliance
A. How Are States Authorized Under RCRA?
B. How Would This Rule Affect State Authorization?
C. Who Would Need to Notify EPA That They Have a Hazardous
Waste?
D. What Would Generators and Transporters Have to Do?
E. Which Facilities Would Be Subject to Permitting?
1. Facilities Newly Subject to RCRA Permit Requirements
2. Existing Interim Status Facilities
3. Permitted Facilities
4. Units
5. Closure
VIII. CERCLA Designation and Reportable Quantities
A. What Is The Relationship Between RCRA and CERCLA?
B. How Does EPA Determine Reportable Quantities?
C. Is EPA Proposing to Adjust The Statutory One Pound RQ for
These Wastes?
D. How Would a Concentration-Based Hazardous Waste Listing
Approach Relate to My Reporting Obligations Under CERCLA? When Would
I Need to Report a Release of These Wastes Under CERCLA?
E. How Would I Report a Release?
F. What Is The Statutory Authority for This Program?
G. How Can I Influence EPA's Thinking on Regulating K179 and
K180 Under CERCLA?
IX. Analytical and Regulatory Requirements
A. Is This a Significant Regulatory Action Under Executive Order
12866?
B. What Consideration Was Given to Small Entities Under The
Regulatory Flexibility Act (RFA), as Amended by The Small Business
Regulatory Enforcement Fairness Act of 1996 (SBREFA), 5 U.S.C. 601
et.seq?
C. What Consideration Was Given to Children's Health Under
Executive Order 13045?
D. What Consideration Was Given to Environmental Justice Under
Executive Order 12898?
E. What Consideration Was Given to Unfunded Mandates?
F. What Consideration Was Given to Federalism Under Executive
Order 13132?
G. What Consideration Was Given to Tribal Governments Under
Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments?
X. Paperwork Reduction Act (PRA), 5 U.S.C. 3501-3520
A. How is The Paperwork Reduction Act Considered in Today's
Proposed Rule?
XI. National Technology Transfer and Advancement Act of 1995 (Pub L.
104-113*12(d) (15 U.S.C. 272 Note))
A. Was The National Technology Transfer and Advancement Act
Considered?
I. Overview
A. Who Potentially Will be Affected by This Proposed Rule?
If finalized, this regulation could potentially affect those who
generate and manage certain paint production wastes. Landfill owners/
operators may also be impacted. A common disposal practice for much of
the paint production wastes of concern has been in solid waste
landfills. This proposed listing may result in leachate from some of
these landfills becoming hazardous under the derived-from rule
(described further in Section V.H). However, impacts to these
facilities are projected to be negligible under our proposed approach
of a Clean Water Act temporary deferral. This action may also affect
entities that need to respond to releases of these wastes as CERCLA
hazardous substances. These potentially affected entities are described
in the Economics Background Document placed in the docket in support of
today's proposed rule. A summary is provided in the table below.
Summary of Facilities Potentially Affected by EPA's 2000 Paint Production Waste Listing Proposal
----------------------------------------------------------------------------------------------------------------
Estimated
number of
Item SIC code NAICS code Industry sector name U.S.
relevant
facilities
----------------------------------------------------------------------------------------------------------------
1............................... 2851 325510 Paint and Coating Manufacturing........ 972
2............................... 4953 562212 Solid Waste Landfill................... 35-48
----------------------------------------------------------------------------------------------------------------
This list of potentially affected entities may not be exhaustive.
Our aim is to provide a guide for readers regarding entities likely to
be regulated by this action. This action, however, may affect other
entities not listed in the table. To determine whether your facility is
regulated by this action, you should examine 40 CFR parts 260 and 261
carefully along with the proposed rules amending RCRA that are found at
the end of this Federal Register notice. If you have questions
regarding the applicability of this action to a particular entity,
consult the person listed in the preceding section entitled FOR FURTHER
INFORMATION CONTACT.
B. What Impact May This Proposed Rule Have?
If you are a paint manufacturer and you generate wastes described
in this
[[Page 10063]]
proposed rule, then you would need to determine if your wastes meet
these newly listed hazardous waste codes, if finalized. Your waste
would become a listed hazardous waste if it contains any of the
constituents of concern at a concentration equal to or greater than the
hazardous concentration identified for that constituent (see Tables IV-
1 and IV-2). If you determine that your wastes are hazardous under this
listing, then the wastes must be stored, treated and disposed in a
manner consistent with the RCRA Subtitle C hazardous waste regulations
at 40 CFR parts 260-272. If your annual generation of these paint
production wastes exceeds 40 metric tons of waste solids and/or 100
metric tons of waste liquids, you must also perform certain routine
testing of the affected wastes and keep certain records of these wastes
(as described in Section V.E) on-site.
We are proposing that generators must meet the necessary conditions
to determine whether or not a waste is hazardous based on the steps
described in Section V.C, of today's proposed rule. If you determine
that your wastes are hazardous under this listing, then you are also
subject to all applicable requirements for hazardous waste generators
in 40 part CFR 262. If you were not previously a hazardous waste
generator, and you determine you generate this newly-listed hazardous
waste; then you must notify the EPA, according to section 3010 of RCRA,
that you generate hazardous waste. Following an initial determination
whether your wastes are hazardous or nonhazardous under this listing,
you would have a continuing obligation to make such a determination at
least on an annual basis.
C. Why Does This Proposed Rule Read Differently From Other Listing
Rules?
Today's proposed hazardous waste listing determination (or
``listing determination'') preamble and regulations are written in
``readable regulations'' format. The authors tried to use active rather
than passive voice, plain language, a question-and-answer format, the
pronouns ``we'' for EPA and ``you'' for the owner/generator, as well as
other techniques, including an acronym list (see below), to make the
information in today's proposed rule easier to read and understand.
This new format is part of our efforts towards regulatory reinvention.
We believe that this new format will help readers understand the
regulations and foster better relationships between EPA and the
regulated community.
Acronyms
------------------------------------------------------------------------
Acronym Definition
------------------------------------------------------------------------
µm............... Micrometer
BDAT..................... Best Demonstrated Available Technology
BFI...................... Browning-Ferris Industries (now Allied Waste
Industries Inc.)
BHP...................... Biodegradation, hydrolysis and photolysis
BIF...................... Boiler and Industrial Furnace
BRS...................... Biennial Reporting System
CAA...................... Clean Air Act
CalEPA................... California Environmental Protection Agency
CARBN.................... Carbon Absorption
CAS...................... Chemical Abstract Services
CBI...................... Confidential Business Information
CERCLA................... Comprehensive Environmental Response
Compensation and Liability Act
CERCLIS.................. Comprehensive Environmental Response
Compensation and Liability Information
System
CESQG.................... Conditionally Exempt Small Quantity Generator
CFR...................... Code of Federal Regulations
CHOXD.................... Chemical or Electrolytic Oxidation
CMBST.................... Combustion
COC...................... Constituents of Concern
CSCL..................... Chemical Stressor Concentration Limit
CSF...................... Cancer Slope Factor
CWA...................... Clean Water Act
CWT...................... Centralized Wastewater Treatment Facility
(May also be referred to as a wastewater
treatment facility, or WWTF)
EDF...................... Environmental Defense Fund
EO....................... Executive Order
EP....................... Extraction Procedure
EPA...................... Environmental Protection Agency
EPACMTP.................. EPA's Composite Model for Leachate Migration
with Transformation Products
EPCRA.................... Emergency Planning and Community Right-To-
Know Act
FR....................... Federal Register
GDP...................... Gross Domestic Product
GNP...................... Gross National Product
HAP...................... Hazardous Air Pollutant
HEAST.................... Health Effects Assessment Summary Table
HQ....................... Hazard Quotient
HSWA..................... Hazardous and Solid Waste Amendments
HWIR..................... Hazardous Waste Identification Rule
ICR...................... Information Collection Request
INC...................... Incineration
IRIS..................... Integrated Risk Information System
ISCST3................... Industrial Source Complex-Short Term
LDR...................... Land Disposal Restriction
MACT..................... Maximum Achievable Control Technology
mg/kg.................... Milligram per kilogram
mg/L..................... Milligram per liter
MLF...................... Municipal Landfill
MINTEQ................... MINTEQ (model for geochemical equilibria in
ground water)
[[Page 10064]]
MINTEQA2................. MINTEQA2 (model for geochemical equilibria in
ground water) Geochemical speciation model;
originally a combination of Mineral
Equilibrium Model (MINEQL) and the
thermodynamic database WATEQ3
MSDS..................... Material Safety Data Sheet
MSW...................... Municipal Solid Waste
MT....................... Metric Ton
NAICS.................... North American Industrial Classification
System
NAPL..................... Non-Aqueous Phase Liquid
NCV...................... National Capacity Variance
NESHAP................... National Emission Standards for Hazardous Air
Pollutants
NPCA..................... National Paint and Coatings Association
NPDES.................... National Pollutant Discharge Elimination
System
NPL...................... National Priority List
NRC...................... National Response Center
NTTAA.................... National Technology Transfer and Advancement
Act
OEM...................... Original Equipment Manufacturing
OMB...................... Office of Management and Budget
OSW...................... Office of Solid Waste
OSWER.................... Office of Solid Waste and Emergency Response
OSWRO.................... Off-Site Waste and Recovery Operations
PBT...................... Persistent, Bioaccumulative and Toxic
POTW..................... Publicly Owned Treatment Works
ppm...................... Parts Per Million
PRA...................... Paperwork Reduction Act
QA....................... Quality Assurance
QC....................... Quality Control
RCRA..................... Resource Conservation and Recovery Act
RFA...................... Regulatory Flexibility Act
RfC...................... Reference Concentration
RfD...................... Reference Dose
RFSA..................... Regulatory Flexibility Screening Analysis
RIC...................... RCRA Information Center
RODS..................... Record of Decision System
RQ....................... Reportable Quantity
RTK...................... Right-To-Know
SBA...................... Small Business Administration
SBREFA................... Small Business Regulatory Enforcement
Fairness Act
SIC...................... Standard Industry Code
SOP...................... Standard Operating Procedure
SPIS..................... Superfund Public Information System
SW-846................... Test Methods for Evaluating Solid Wastes
TC....................... Toxicity Characteristic
TCLP..................... Toxicity Characteristic Leaching Procedure
TOC...................... Total Organic Carbon
TRI...................... Toxic Release Inventory
TSDF..................... Treatment, Storage and Disposal facility
TSDR..................... Toxic Substances and Disease Registry
TSS...................... Total Suspended Solids
UMRA..................... Unfunded Mandates Reform Act
USC...................... United States Code
USLE..................... Universal Soil Loss Equation
UTS...................... Universal Treatment Standard
VOC...................... Volatile Organic Compound
WETOX.................... Wet Air Oxidation
WMU...................... Waste Management Unit
WMX...................... WMX Technologies, Inc.
------------------------------------------------------------------------
D. What Are The Statutory Authorities for This Proposed Rule?
These regulations are being proposed under the authority of
sections 2002(a), 3001(b), 3001(e)(2), 3004(d)-(m), and 3007(a) of the
Solid Waste Disposal Act, 42 U.S.C. 6912(a), 6921(b) and (e)(2),
6924(d)-(m), and 6927(a), as amended, most importantly 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 under which EPA is proposing amendments to 40 CFR part
302.
II. Background
A. How Does EPA Define a Hazardous Waste?
EPA's regulations establish two ways of identifying solid wastes as
hazardous under RCRA. A waste may be considered hazardous if it
exhibits certain hazardous properties (``characteristics'') or if it is
included on a specific list of wastes EPA has determined are hazardous
(``listing'' a
[[Page 10065]]
waste as hazardous) because it was found to pose substantial present or
potential hazards to human health or the environment. EPA's regulations
in the Code of Federal Regulations (40 CFR) define four hazardous waste
characteristic properties: Ignitability, corrosivity, reactivity, or
toxicity (See 40 CFR 261.21-261.24). As a generator, you must determine
whether or not a waste exhibits any of these characteristics by testing
the waste, or by using your knowledge of the process that produced the
waste (see Sec. 262.11(c)). While you are not required to sample your
waste, you will be subject to enforcement actions if you are found to
be improperly managing materials that are characteristic hazardous
waste.
EPA may also conduct a more specific assessment of a waste or
category of wastes and ``list'' them if they meet criteria set out in
40 CFR 261.11. As described in Sec. 261.11, we may list a waste as
hazardous if it:
--Exhibits any of the characteristics noted above, i.e., ignitability,
corrosivity, reactivity, or toxicity (261.11(a)(1));
--Is ``acutely'' hazardous, i.e., if they are fatal to humans or in
animal studies at low doses, or otherwise capable of causing or
significantly contributing to an increase in serious illness
(261.11(a)(2)); or
--Is capable of posing a substantial present or potential hazard to
human health or the environment when improperly managed (261.11(a)(3)).
Under the third criterion, at 40 CFR 261.11(a)(3), we may decide to
list a waste as hazardous if it contains hazardous constituents
identified in 40 CFR part 261, appendix VIII, and if, after considering
the factors noted in this section of the regulations, we ``conclude
that the waste is capable of posing a substantial present or potential
hazard to human health or the environment when improperly treated,
stored, transported, or disposed of, or otherwise managed.'' We place a
chemical on the list of hazardous constituents on Appendix VIII only if
scientific studies have shown a chemical has toxic effects on humans or
other life forms. When listing a waste, we also add the hazardous
constituents that serve as the basis for listing to 40 CFR part 261,
appendix VII.
The regulations at 40 CFR 261.31 through 261.33 contain the various
hazardous wastes the Agency has listed to date. Section 261.31 lists
wastes generated from non-specific sources, known as ``F-wastes,'' and
contains wastes that are usually generated by various industries or
types of facilities, such as ``wastewater treatment sludges from
electroplating operations'' (see code F006). Section 261.32 lists
hazardous wastes generated from specific industry sources, known as
``K-wastes,'' such as ``Spent potliners from primary aluminum
production'' (see code K088). Section 261.33 contains lists of
commercial chemical products and other materials, known as ``P-wastes''
or ``U-wastes,'' that become hazardous wastes when they are discarded
or intended to be discarded.
Today's proposed regulations would list certain paint production
wastes as K-waste codes under Sec. 261.32. We are also proposing to add
constituents that serve as the basis for the proposed listings to
Appendix VII as well as to add certain constituents to the list of
Hazardous Constituents in Appendix VIII that are not already included.
``Derived-from'' and ``Mixture'' Rules
Residuals from the treatment, storage, or disposal of most listed
hazardous wastes are also classified as hazardous wastes based on the
``derived-from'' rule (40 CFR 261.3(c)(2)(i)). For example, ash or
other residuals generated from the treatment of a listed waste
generally carries the original hazardous waste code and is subject to
the hazardous waste regulations. Also, the ``mixture'' rule (40 CFR
261.3(a)(2)(iii) and (iv)) provides that, with certain limited
exceptions, any mixture of a listed hazardous waste and a solid waste
is itself a RCRA hazardous waste.
Some materials that would otherwise be classified as hazardous
wastes under the rules described above are excluded from jurisdiction
under RCRA if they are recycled in certain ways. The current definition
of solid waste at 40 CFR 261.2 excludes from the definition of solid
waste secondary materials that are used directly (i.e., without
reclamation) as ingredients in manufacturing processes to make new
products, used directly as effective substitutes for commercial
products, or returned directly to the original process from which they
are generated as a substitute for raw material feedstock. (See 40 CFR
261.2(e).) As discussed in the January 4, 1985, rulemaking that
promulgated this regulatory framework, these are activities which, as a
general matter, resemble ongoing manufacturing operations more than
conventional waste management and so are more appropriately classified
as not involving solid wastes. (See 50 FR 637-640).
B. How Does EPA Regulate RCRA Hazardous Wastes?
If a waste exhibits a hazardous characteristic or is listed as a
hazardous waste then it is subject to federal requirements under RCRA.
These regulations affect persons who generate, transport, treat, store
or dispose of such waste. Facilities that must meet 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 regulations for hazardous wastes as may
be necessary to protect human health or the environment. EPA standards
and procedural regulations implementing Subtitle C are found generally
at 40 CFR parts 260 through 272.
All RCRA hazardous wastes are also hazardous substances under the
Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA), as defined in section 101(14)(C) of the CERCLA statute. This
applies to wastes listed in Secs. 261.31 through 261.33, as well as any
wastes that exhibit a RCRA characteristic. Table 302.4 at 40 CFR 302.4
lists CERCLA hazardous substances along with their reportable
quantities (RQs). Anyone spilling or releasing a substance at or above
the RQ must report the release to the National Response Center, as
required in CERCLA Section 103. In addition, Section 304 of the
Emergency Planning and Community Right-to-Know Act (EPCRA) requires
facilities to report the release of a CERCLA hazardous substance at or
above its RQ to State and local authorities. Today's rule proposes to
establish RQs for the newly listed wastes.
C. How Does EPA Regulate Solid Wastes That Are Not RCRA Hazardous
Wastes?
If your waste is a solid waste but is not, or is determined not to
be a listed and/or characteristic hazardous waste, then you may dispose
these solid wastes at Subtitle D facilities. These facilities are
approved by state and local governments and generally impose less
stringent requirements on management of wastes. Subtitle D is the
statutory designation for that part of RCRA that deals with disposal of
solid waste. EPA regulations affecting Subtitle D facilities are found
at 40 CFR parts 240 thru 247, and 255 thru 258. Regulations for
Subtitle D landfills that accept municipal waste (``municipal solid
waste landfills'') are in 40 CFR part 258.
[[Page 10066]]
D. Overview of the Hazardous Waste Listing Determination Process for
Paint Production Wastes
1. Suspension of Previous Listings
Under the Resource Conservation and Recovery Act (RCRA) of 1976,
Congress directed EPA to establish a framework for RCRA's Subtitle C
hazardous waste program. Congress also required EPA to propose and
write timely rules identifying wastes as hazardous under Subtitle C.
EPA responded by proposing Subtitle C regulations on December 12, 1978
(43 FR 58957) which established a framework for the Subtitle C program.
At the same time, EPA also proposed to list wastes--including four
paint production waste streams from specific (paint production) sources
and two paint production waste streams from non-specific (paint
application) sources--as hazardous. On July 16, 1980, EPA promulgated
an interim final rule (45 FR 47832) that designated four paint
production waste streams from specific sources as hazardous waste under
40 CFR 261.32:
Solvent cleaning wastes from equipment and tank cleaning
operations (K078),
Water/caustic cleaning wastes from equipment and tank
cleaning operations (K079),
Wastewater treatment sludge (K081), and
Emission control dust or sludge (K082).
Commenters to this rule argued that these listings were overly
broad. EPA consequently re-examined the data and initial analysis on
these paint production waste streams and determined that further study
of these wastes was necessary before a final listing could be
promulgated. On January 16, 1981, this interim final rule--identifying
and listing these paint production waste streams as hazardous--was
temporarily suspended (48 FR 4614).
2. Consent Decree Schedule for This Proposal
The 1984 Hazardous and Solid Waste Amendments (HSWA) to RCRA
require EPA to make listing determinations for paint production wastes
(see RCRA section 3001(e)(2)). In 1989, the Environmental Defense Fund
(EDF) filed a lawsuit to enforce the statutory deadlines for listing
decisions in RCRA section 3001(e)(2). (EDF v. Browner, D.D.C. Civ. No.
89-0598). To resolve most of the issues in the case, EDF and EPA
entered into a consent decree, which has been amended several times to
revise deadlines for EPA action. Paragraph 1.d (as amended) of the
consent decree addresses the paint production industry:
EPA shall promulgate a final listing determination for paint
production wastes on or before March 30, 2002. This listing
determination shall be proposed for public comment on or before
January 28, 2001. This listing determination shall include the
following wastes: solvent cleaning wastes (K078), water/caustic
cleaning wastes (K079), wastewater treatment sludge (K081), and
emission control dust or sludge (K082) for which listings were
suspended on January 16, 1981 (46 FR 4614), and off-specification
production wastes.
Today's proposal satisfies EPA's duty under paragraph 1.d to
propose determinations for the specified paint production wastes.
E. Existing Regulations That Apply to This Industry
RCRA authorizes EPA to evaluate industry waste management practices
and, if necessary, regulate how wastes are handled to ensure that
present or potential hazards are not posed to human health and the
environment. In addition to RCRA, the Clean Water Act (CWA) and Clean
Air Act (CAA) provide EPA with the statutory authority to evaluate
industry practices and, if necessary, regulate industry releases of
pollutants to environmental media such as water and air.
Currently, there are no regulatory requirements under RCRA that
specifically--identify paint production waste streams as listed
hazardous waste. Paint production waste streams may, however, carry
hazardous waste listing and/or characteristic codes if they are
generated from the use of certain common organic solvents (spent
solvent wastes F001 through F005) or if they exhibit a hazardous waste
characteristic (ignitability--D001, corrosivity--D002, reactivity--
D003, toxicity--D004--D043). EPA is not soliciting comment on these
existing hazardous waste listings and does not intend to respond to
such comments if received. As well, paint production wastes subject to
today's proposal remain subject to current hazardous waste listings or
characteristics that render them hazardous.
Regulatory requirements under the CWA (40 CFR part 446) specify
effluent guidelines implemented through national pollutant discharge
elimination system (NPDES) permits for certain paint production wastes
that are discharged to navigable waters. These regulations apply to
paint production wastes that originate from the production of oil-based
paint where tank cleaning is performed using solvents. In addition,
manufacturers who discharge wastewaters generated from paint production
to a publicly owned treatment works (POTW) may be required to comply
with general pretreatment requirements (40 CFR part 403) as established
by the POTW. Finally, some paint manufacturers send their wastewaters
to privately-owned centralized wastewater treatment facilities (CWTs)
that are operated under NPDES permits. The Agency recently promulgated
effluent guidelines for these facilities at 40 CFR part 437.
Under the CAA there are two types of regulatory requirements that
may apply specifically to paint production wastes: National volatile
organic compound (VOC) emission standards and national emission
standards for hazardous air pollutants (NESHAP). VOC emission
standards--which aim to reduce VOC emissions and in turn reduce ozone
levels--exist for architectural coatings (40 CFR part 59, subpart D; 63
FR 48848, September 11, 1998) and automobile refinish coatings (40 CFR
part 59, subpart B; 63 FR 48806, September 11, 1998). These standards
specify VOC levels for categories of architectural and automobile
refinish coatings.
Subpart DD in 40 CFR part 63, sets NESHAPs from off-site waste and
recovery operations (OSWRO). These standards, in part, limit air
releases from off-site wastewater treatment facilities (CWTs) (July 1,
1996, 61 FR 34140). Furthermore, EPA is planning to propose a MACT
(Maximum Achievable Control Technology) standard for paint
manufacturers (Miscellaneous Organic Chemical and Coatings
Manufacturing) that would regulate hazardous air pollutant (HAP)
emissions from process vents, storage tanks, transfer operations,
equipment leaks, and wastewaters.\1\ This would apply to wastewaters
managed on-site and also if sent off-site for treatment.
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\1\ These regulations would apply to coatings manufacturing
facilities that are a major source and use, produce, or make a HAP.
A major source of a HAP is located within a contiguous area and
under common control and has the potential to emit greater than 9.1
Mg/yr (25 tons/yr) of any combination of HAP or 10 tons/yr of a
single HAP.
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F. What Industries and Wastes Are Covered in This Proposed Rule?
1. Scope of Consent Decree
Today's proposed rule applies to paint and coatings manufacturers
generally categorized under subcodes 28511, 28512, and 28513 of
Standard Industrial Code (SIC) 2851, or North American Industry
Classification System (NAICS) 325510 (subcodes -1, -4, and -7). This
includes, but is not limited to, entities who manufacture:
[[Page 10067]]
paints (including undercoats, primers, finishes, sealers, enamels,
refinish paints, and tinting bases), stains, varnishes (including
lacquers), product finishes for original equipment manufacturing and
industrial application, and coatings (including special purpose
coatings and powder coatings). Products produced by this industry that
are included within the scope of this proposed rule are referred to as
``paints'' and/or ``coatings.''
Today's proposal does not apply to miscellaneous allied products
(paint and varnish removers, thinners for lacquers and other solvent-
based paint products, pigment dispersions or putty) included under SIC
subcode 28515 (NAICS 325510A) or artist paint, which is classified
under SIC 3952 (NAICS 339942).
The waste streams included within the scope of today's proposal are
the following paint production wastes generated by paint manufacturers:
(1) Solvent cleaning wastes as waste liquids and solids generated from
equipment and tank cleaning operations; (2) water and/or caustic
cleaning wastes as waste liquids and solids generated from equipment
and tank cleaning operations; (3) wastewater treatment sludge as waste
solids generated in on-site or captive wastewater treatment processes
solely or primarily for treating paint production waste liquids; (4)
emission control dust or sludge as waste solids collected in a
facility's particulate emission control devices such as baghouses; and
(5) off-specification production wastes as waste solids.
EPA bases many of its decisions as to the scope of the industries
and wastes covered in this proposal on the EDF v. Browner consent
decree. Paragraph 1.d of the consent decree states:
Paint production wastes--EPA shall promulgate a final listing
determination for paint production wastes on or before March 30,
2002. This listing determination shall be proposed for comment on or
before January 28, 2001. This listing determination shall include
the following wastes: solvent cleaning wastes (K078), water/caustic
cleaning wastes (K079), wastewater treatment sludge (K081), and
emission control dust or sludge (K082) for which listings were
suspended on January 16, 1981 (46 FR 4614), and off-specification
production wastes. (Emphasis added)
For solvent cleaning wastes, water/caustic cleaning wastes,
wastewater treatment sludge and emission control sludge or dust, we
believe that the decree requires us to address only those industries
and wastes included in the paint production wastes listing that the
Agency suspended on January 16, 1981. After reviewing the original
rulemaking record for the suspended interim final rule, we have
determined that while EPA did initially look at the entire paint and
coatings SIC classification, which included miscellaneous allied
products, we ultimately narrowed the scope of the suspended paint
listings to exclude this category. Therefore, manufacturers of allied
products and allied products production wastes are not covered by the
decree. Moreover, nothing in the 1980 rulemaking record suggests that
artist materials were considered in this earlier listing development
work. Therefore, EPA does not interpret the decree to require
assessment of solvent cleaning wastes, water/caustic cleaning wastes,
wastewater treatment sludge, and emission control sludge or dust from
the production of artist paint. (For more information on how EPA
determined the scope of the suspended paint listings, refer to the
accompanying Listing Background Document.)
Concerning ``off-specification production waste,'' we believe that
the most straightforward reading of the consent decree is that this
waste stream, although not part of the suspended listings, has the same
scope as the other enumerated waste streams. In other words, the decree
does not require us to address off-specification allied products and
artist paints. Nothing in the decree suggests that either party
intended the off-specification production waste stream to apply more
narrowly or more broadly than the other waste streams. Thus, EPA has
assessed only off-specification paint production wastes from subcodes
28511, 28512, and 28513 of Standard Industrial Code (SIC) 2851.
EPA, however, interprets the decree to exclude off-specification
paint products that have been shipped out to retailers or paint users.
EPA believes that these downstream entities do not engage in paint
production. Consequently, EPA has not evaluated off-specification paint
which a downstream entity decides to discard or send back to the
manufacturer. Moreover, as explained below, EPA thinks that downstream
entities can presume that unused paint products returned to a paint
production facility will be legitimately reused and, thus, will not be
solid wastes, even if they exhibit a hazardous waste characteristic.
2. Scope of Listing: Off-Specification Products
EPA is proposing to include within the category of off-
specification paints all products which a paint manufacturer decides
not to use--whether or not the paint product meets applicable product
specifications. Not all of these unused products literally fail to meet
product specifications; paint producers cite a variety of reasons for
deciding not to sell them as originally intended. EPA believes that any
unused products, whatever the reason they are unused, could present
similar risks. Moreover, facilities would find it cumbersome to
distinguish between off-specification products and other unused
products.
EPA is proposing not to go beyond the scope of the consent decree
to include within the listing off-specification paint products which
retailers or users decide to discard or return to manufacturers.
However, EPA is proposing to go beyond consent decree requirements to
include within the scope of today's proposed listing returned, unused
products once a manufacturer obtains possession or control of them. EPA
believes that ``returned'' unused products could pose risks similar to
those posed by unused products that never go off-site. And, as
discussed above, facilities would find it cumbersome to distinguish
between returned products and ``never sent'' products. EPA refers to
all of these unused products that will not be sold for their original,
intended use as ``off-specification'' paint products.
3. Recycling Issues
EPA notes that off-specification paint production wastes can be
recycled in ways that will not be regulated as hazardous waste
management. Under current regulations defining ``solid wastes,'' unused
paint reused as a legitimate ingredient in the manufacture of other
paint is not considered a ``waste'' and thus will not be subject to the
hazardous waste regulations. EPA notes that paint manufacturers
commonly reuse unused products to make new paints. EPA also understands
that paint formulations are fairly exacting, making it unlikely that a
manufacturer could successfully rework paint containing significant
quantities of constituents that are not useful paint ingredients.
Typically, this type of reuse of a commercial product (when legitimate)
is not regulated as waste management, even if it involves reclamation.
See 40 CFR 261.2 \2\ In addition, relatively small quantities are sold
for ``lower-grade'' uses; these materials are still paint products, and
no aspect of this activity is regulated under RCRA Subtitle C.
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\2\ See also: Letter from Sylvia K. Lowrance to Mark Schultz,
May 16, 1991. This letter says that returned pharmaceutical products
are not considered solid wastes until a decision is made to discard
them, because use/reuse is generally a viable option.
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EPA wants to clarify the effect of today's proposed listing on
``take-back''
[[Page 10068]]
programs in which retailers or customers return unused paint because it
does not meet the customer's specifications or because it is unusable
for some other reason. EPA believes, based on what it knows of the
industry, that a retailer or customer returning unused paint to a paint
manufacturer can presume that the paint will be legitimately used as an
ingredient and that, therefore, the paint being returned is not a
hazardous waste even if it exhibits a hazardous waste characteristic.
EPA understands that paint manufacturers will typically take such
returned paint and use it as a legitimate ingredient in the manufacture
of another paint product. The retailer or user will be entitled to rely
on this interpretation exempting returned paint even if the
manufacturer ultimately decides to discard the unused paint rather than
reuse it. EPA has previously taken the position that retailers or users
of pharmaceutical products returning unused products to manufacturers
are not managing wastes \3\. However, should the paint production
facility determine it cannot or will not use the returned paint as an
ingredient, we are proposing that the paint would then become an off-
specification paint product waste that would need to be evaluated
against the concentrations proposed in today's rulemaking, as well as
the hazardous waste characteristics.
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\3\ Letter from David Bussard to N.G. Kraul, February 23, 1993.
This letter says that off-specification paint is a non-listed
commercial product and not a solid waste when reclaimed.
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G. Description of The Paint and Coatings Industry
Paint and coatings manufacturers are concentrated near large
metropolitan areas, with the majority of facilities located on the East
Coast, and in California, Texas and the Midwest. We estimate that there
are 972 paint and coatings manufacturing facilities operated in the
United States by about 780 different companies (a few larger companies
operate several facilities). For more information on how we estimated
this universe, refer to Section II.H. Of this universe, we estimate
that about 95 percent of all these companies meet the Small Business
Administration definition of a small business (total company employment
of fewer than 500 people, at the parent level, if a company is a
subsidiary). We estimate that around 600 facilities are generating
wastes that fall within the scope of this rulemaking.
The paint and coatings industry is classified by the type of paint
product manufactured. Products are categorized into three main groups
according to end use by the SIC classification as architectural
coatings, original equipment manufacturing (OEM) product finishes, and
special purpose coatings. Architectural coatings, also referred to as
trade sales paints, include exterior and interior house paints, stains,
varnishes, undercoats, primers, and sealers. OEM product finishes are
custom formulated for application to products during the manufacturing
process. This includes coatings applied to automobiles, appliances,
machinery and equipment, toys and sporting goods, wood furniture and
fixtures, coil coatings, electrical insulation, factory-finished wood,
metal containers, paper, film and foil, and non-automotive
transportation. Special purpose paints are formulated for specific
applications or extreme environmental conditions (fumes, chemicals, and
temperature) and include: high-performance maintenance coatings (used
in refineries, public utilities, bridges, etc.); automotive
refinishing; highway traffic markings; aerosol paints; and marine
coatings.
Paint Production. Paints and coatings are formulated to protect and
decorate surfaces as well as enhance desired surface properties such as
electrical conductivity and corrosion protection. Inorganic and organic
chemicals comprise raw materials--solvents, resins (or ``binders''),
pigments, and additives--that are mixed in a batch process to make
solvent or water-based paint according to desired end-use
specifications. Batches of paint, which may range in size from 10 to
10,000 gallons, are blended in stationary and portable equipment such
as mixers, blenders, sand mills, and tanks.
Paint Production Waste Generation and Management. Process equipment
is cleaned regularly to avoid product contamination and to restore
operational efficiency. The equipment is also cleaned during
manufacturing shut downs and when a significant change in a production
line occurs. Because paint is a mixture of chemicals that does not
involve chemical reactions, the make-up of paint production wastes
reflects chemicals used in batch production and any ancillary chemicals
such as those used in cleaning process equipment. Depending on the type
of paint manufactured, process equipment may be cleaned with either
solvent, water, or aqueous caustic washes. These liquid cleaning wastes
consist of paint solids and sludges which may contain pigments,
partially or completely cured resins, and additives. Solvent cleaning
wastes, as well as water and/or caustic cleaning wastes are defined by
the type of cleaning reagent used, not by the material that is being
removed through the cleaning process. For example, you can generate a
solvent cleaning waste if you clean a wastewater tank with a solvent
(or blend of solvent).
Paint manufacturing facilities may also generate waste solids and
liquids included within the scope of this proposed rule when (1)
emission control systems are emptied, (2) wastewaters are treated and
(3) off-specification product is discarded. Airborne material is
generated when dry materials, such as pigments, are loaded into
processing equipment. Air hoods and exhaust fans help control the level
of airborne particulate material released into the paint production
areas. Material is collected in emission control systems such as
baghouses. Pigments comprise a large fraction of the dry materials
collected in emission control systems. Other raw materials, including
additives (such as fillers) and solvents, may also be collected in
emission control systems.
Water-based wastewaters are primarily generated when process
equipment is cleaned. Additional sources include floor washdown and
spill cleanup. The most common treatment for these wastewaters is
physical-chemical. This usually involves chemical addition and gravity
settling of suspended solids which generates a liquid and sludge.
As discussed above in Section II.F, ``off-specification'' paint
products subject to this listing determination include any unused paint
products which a paint manufacturer decides to handle in a way that is
regulated as waste management. A paint may be considered off-
specification for a variety of reasons. For example, it may not meet
the original design specifications; it may be replaced by a new
superior production; or, the product's shelf life expires. As discussed
earlier, off-specification paint products may be reworked into saleable
materials or discarded. Off-specification product that is discarded by
a paint manufacturer is subject to this listing.
Paint manufacturers may generate some or all of these wastes. Waste
generation is a function, in part, of volume and type of paint
produced, degree of automation, amount of recycling, and age of
facility. Treating, handling, and disposing of these wastes are costs
associated with paint production activities. Paint manufacturers strive
to reduce and/or eliminate waste produced which in turn reduces overall
costs and improves profitability and competitiveness.
[[Page 10069]]
H. What Information Did EPA Collect and Use?
Our primary sources of data to support this proposed listing
determination are a questionnaire (or ``survey'') of the paint and
coatings manufacturing industry and existing literature. We conducted a
survey under authority of RCRA section 3007, 42 U.S.C. 6927.\4\ As part
of the survey development process, we went on ten site visits to paint
manufacturing facilities throughout the country.
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\4\ See Federal Register notices 4 FR 46375 (August 25, 1999)
and 64 FR 71135 (December 20, 1999) announcing EPA's data collection
request submitted to the Office of Management and Budget (OMB). A
copy of the questionnaire is available in the public docket for
today's proposed rule. This information collection request was
approved by the OMB, Clearance Number 2050-0168 (expiration date:
June 30, 2001).
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Please note that we did not sample waste streams generated by the
paint and coatings industry to support this proposed listing
determination. As discussed earlier, there are about 1000 paint
manufacturing facilities in the U.S. paint and coatings industry. These
facilities combine raw materials (chosen from a potential universe of
several thousand constituents) in batch processes to manufacture
products that meet market demands for a wide variety of architectural,
original equipment manufacture and product coatings, and special
purpose needs. Waste streams generated at a facility (the same or
different facility) may vary significantly because the type of product
manufactured, as well as raw materials used, vary significantly. As a
result, we did not attempt to sample paint production wastes described
in this proposal because we concluded it would be impractical to
conduct a data collection effort that would account for the wide
variety of individual paint products produced and the potential
variability in the waste characteristics. Gathering sufficient samples
to evaluate all potential paint production wastes would require a large
commitment of scarce Agency resources that would have been beyond the
reasonable scope of this rulemaking. In addition, an advantage of the
concentration-based listing approach that we have used in this proposal
is that it does not rely on extensive waste sampling. Instead, we are
relying on publically available sources of information as well as data
collected from survey responses to characterize the constituents likely
to be present and the chemical and physical properties of paint
manufacturing wastes.
1. Site Visits
To develop a better understanding of industry practices and as a
basis for developing the industry survey, the Agency conducted site
visits at ten paint manufacturing plants located throughout the
country. When selecting sites, we considered: plant production size,
type of manufacturing process, Toxic Release Inventory (or ``TRI'')
waste release information, and plant location. The information we
obtained from these visits (other than that for which a Confidential
Business Information (CBI) claim has been made and sustained) is
available for public review in the docket for this rulemaking. (For
more information about CBI protection, please refer to 40 CFR part 2
subpart B.)
In particular, we collected information on: (1) Types of production
and volume, (2) waste management units used, (3) how each residual was
managed (as hazardous or not), (4) evidence of off-spec product storage
and tracking system, (5) volume of each residual generated and form and
how each is stored on-site, (6) management practices for each residual
for both on-site and off-site (POTWs, tanks), (7) types of constituents
used at plant, (8) reuse of solvent/washwater (e.g., washwater used as
ingredient in next batch), (9) pollution prevention and waste
minimization practices, (10) presence or absence of solvent recovery
stills on-site, (11) presence or absence of any closed loop recycling
practices, (12) any appearance of unsafe operating practices or
disposal practices by facility, and (13) housekeeping practices on
plant floor relative to waste generation and management.
We used information collected at these on-site visits combined with
additional information provided by industry representatives to develop
a RCRA 3007 survey. For example, we were able to include more
appropriate questions on waste management practices and to distinguish
wastes that are recycled more clearly. This survey requests information
on waste generation and management practices.
2. Database of Paint Manufacturing Information From Published Sources
We also created an electronic Database of Paint Manufacturing
Information from Published Sources that is available in the docket. The
database consists of three modules. The Raw Materials Module contains
information on different categories of raw materials that are combined
to make paints. The Paint Formulations Module contains information on
the concentrations of different raw materials in selected paint
formulations. The Bibliography of Documents Module lists the published
reference materials which were used as sources for other modules in the
database. These sources include technical texts, journal articles, EPA
and other government studies, and publications from paint industry
trade organizations.
3. The RCRA Section 3007 Survey
a. Overview. The purpose of the survey was to gather information
about nonhazardous and hazardous waste generation and management
practices in the U.S. paint and coatings manufacturing industry.
Specifically, we requested information on the five waste streams of
concern (as outlined in the Consent Decree obligations, See Section
II.D.2), waste characteristics, and waste management practices.
In addition to determining the content of the survey, we also
evaluated whether it was necessary to conduct a census of the industry
in order to accurately depict this industry's current waste generation
and management practices. Due to the size of the paint manufacturing
industry, and in consideration of our time and resource constraints, we
could not conduct a full census of all the facilities in the industry.
Therefore, we surveyed a sample of the universe rather than conduct a
full census. Random sampling is a widely used statistical approach to
collecting representative data from a large population. To ensure that
this survey would provide the best overall coverage for various
industry subsets and identify all significant waste management
practices throughout the industry, we used accepted statistical
sampling methods to achieve a 90% probability or confidence level that
our survey would find a waste management activity utilized by at least
one in 20 paint manufacturing facilities within the various categories
of generators we identified via our literature search (discussed
below). In other words, we determined a sample size such that it would
be large enough to ensure a high certainty (90% likelihood) of
identifying any waste management practices with more than 5% chance of
occurrence. Using a statistical stratified random-sampling scheme \5\
designed to represent
[[Page 10070]]
paint production types, sales volumes and TRI reporting status, we
selected sufficient paint manufacturing facilities from an industry
database developed by Dun & Bradstreet, a company of The Dun &
Bradstreet Corporation, 2000. We believe this sampling survey
adequately covered the industry while reducing the burden imposed by
the survey on the industry and reducing the time and money spent by the
government in performing the survey.
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\5\ Stratified random sampling is a statistical procedure that
first dividends the sampling population into subpopulations or
strata with respect to several characteristics such that within the
individual strata there is as much homogeneity as possible, and then
selects samples randomly from the individual strata. This procedure
improves generalizations about the whole population and, if properly
executed, generally leads to a higher degree edition, Prentice-Hall,
Inc., 1967.
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Prior to finalizing the questionnaire, we conducted a pilot test by
sending the questionnaire to three paint manufacturing facilities which
were not included in the survey and modified the questionnaire based on
their comments. Further, in order to assist the surveyed facilities in
understanding and responding to the questionnaire, we established toll-
free telephone and e-mail help lines, returned and answered their calls
or messages expeditiously, and even helped some complete the
questionnaire over the telephone. Note that, under RCRA section 3007,
the surveyed facilities are required to provide accurate information
and certify under penalty of law. However, to ensure accuracy and
completeness, we conducted a quality assurance review of the
information and data provided in the questionnaire responses, such as
identifying data entry errors, missing data, and internal
inconsistencies between answers. The review of each facility's response
resulted in follow-up telephone calls and/or letters to some facilities
seeking clarifications, corrections, and additional/missing data where
needed. We entered data from the questionnaire responses into a
database known as the Paint Residual Master Database, and conducted
additional quality assurance reviews on the database. Hard copies of
the questionnaire responses and a CD-ROM copy of the response database
are available in the public docket for review.
We compiled and analyzed these data to develop a general assessment
of the paint industry's waste generation and management practices. We
also used these data for our risk assessment, economic analysis of the
potential impacts of hazardous waste regulation, and Land Disposal
Restrictions (LDR) and treatment and management capacity analyses.
b. Structuring The Survey to Capture All The Wastes of Concern. As
indicated previously, the consent decree obligations require the Agency
to make hazardous waste listing determinations on five types of paint
production wastes. In the questionnaire, we classified these five waste
streams into 20 specific residuals for more detailed waste
characterization. These 20 residuals, including ten hazardous and ten
nonhazardous under current Federal regulations, encompass liquid
residual from solvent cleaning, sludge residual from solvent cleaning,
liquid residual from wash water, sludge residual from wash water,
liquid residual from caustic wash water, sludge residual from caustic
wash water, sludges from wastewater treatment, emission control dust,
emission control sludge, and off-specification product. As discussed
later in Sections III and IV, we eventually used the detailed waste
characterization information from the survey to divide the paint
production waste streams of concern into waste solids and waste liquids
for today's proposed listing.
c. Identifying The Universe of Paint Manufacturing Facilities.
Initially, using a variety of industrial and business data sources
described in the listing background document, we estimated that there
are approximately one thousand paint manufacturing facilities of
interest in the United States. We found no single, comprehensive
listing of all paint manufacturing facilities. However, we identified
the 1998-99 Dun & Bradstreet database as the data source that would
provide the most thorough listing of paint manufacturers in the United
States that was available in electronic format. We used the Dun &
Bradstreet database to develop a sampling population and to stratify
the sampling population into categories based on paint types and sales
volumes. We also looked at the American Business Directories List of
paint and allied product manufacturers and the 1999 Paint Red Book
published by Cygnus Publishing, but found that they were less suitable
to our needs for sampling stratification purposes. We found that there
was insufficient information in the latter two databases for us to
distinguish the types of paint production by facilities and whether
some facilities were clearly out of scope and classify them into our
desired paint production categories (architectural, OEM, etc.). The Dun
& Bradstreet database includes a well defined and easily understandable
breakdown of the various paint manufacturing types we used to classify
them into OEM and architectural related paint categories, and eliminate
those apparently of no interest to this listing determination.
Specifically, each entry in the Dun & Bradstreet database is identified
by an 8-digit code, with the first four being the same as SIC's and the
next four proprietary to Dun & Bradstreet that represent the
classifications of the facilities. The coding system used in the Dun &
Bradstreet database provided the level of detail necessary to more
accurately divide the paint industry into the necessary strata for our
use.
d. Constructing a Stratified Random Sample. We stratified paint
manufacturing facilities into various categories for this sampling
survey because we expected we might find differences in waste
generation and management practices among various types of paint
producers (architectural, OEM, etc.) and by sampling the various
categories we would be more likely to identify the full range of
management practices. We also believed that larger facilities (with
higher sales volumes) conduct more waste management activities, and
smaller facilities (with lower sales volumes) tend to have more
recycling or reuse efforts in order to compete in business.
Furthermore, manufacturing facilities subject to the Toxic Release
Inventory (TRI) \6\ reporting are required to report annual releases of
toxic chemicals to waste management units and environmental media. As
such, we were particularly interested in SIC 2851 paint manufacturers
that are listed under TRI because they would also likely provide more
information on waste constituents and management practices of concern
to this listing determination. Therefore, we stratified the facilities
based on three categorization criteria: Paint types, sales volumes, and
TRI status, as elaborated below.
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\6\ The Toxic Release Inventory (TRI) of routine and accidental
releases of toxic chemicals to the environment reported by
manufacturing facilities, established per Section 313 of the
Emergency Planning and Community Right-to-Know Act of 1986.
Facilities conducting the specified manufacturing operations are
required to report on releases of certain toxic chemicals into the
air, water, and land provided certain conditions (having ten or more
full-time employees, and manufacturing or processes over 25,000
pounds of the designated chemicals, etc.) are met.
---------------------------------------------------------------------------
In the Dun & Bradstreet database, we found a total of 1,764
facility entries identified under SIC 2851. We removed those entries
that are either apparent non-paint manufacturers, or entries we
determined that are outside of the scope of this listing determination,
or entries we found impossible to identify for stratification purposes.
In the end, we adopted the remaining 884 facilities as the sampling
population for this survey.
Next, we stratified the 884 potential paint manufacturing
facilities into 12 categories, based on the three categorization
criteria discussed above: paint types; sales volumes (less than
[[Page 10071]]
five million dollars, five to twenty million dollars, and greater than
twenty million dollars, based on the Census Bureau's figures); and TRI
status (whether the facility reported under TRI in 1997). These 12
categories comprise large, medium, and small facilities of the
following combinations: Architectural-related production and on the TRI
list; OEM-related production and on the TRI list; architectural-related
production and not on the TRI list; OEM-related production and not on
the TRI list. Also note that three categories contained no facilities:
medium architectural-related paint production and on the TRI list,
large OEM-related paint production and on the TRI list, and medium OEM-
related paint production and on the TRI list.
To select a sample from the 884 sampling population for
distributing the questionnaire, we developed a stratified, statistical
random-sampling scheme based on the above stratification process and
using the hypergeometric probability formula described in Steel and
Torrie,\7\ such that the sample size would represent a 90% probability
of capturing a waste management practice conducted by at least one in
20 facilities (discussed above). Under these criteria, higher
percentages of facilities were selected in the medium and large
facility categories. All selected facilities were then randomly chosen
within the various categories to avoid bias when sending questionnaires
to the surveyed facilities. This sampling approach reduced the
probability of including known non-paint manufacturers or manufacturers
not of interest to this rulemaking in the survey, and increased the
chance of capturing sufficient waste management activities. Otherwise,
more of the small facilities would have been surveyed, but large
manufacturing facilities and TRI generators which would likely provide
more waste management information could have been left out.
---------------------------------------------------------------------------
\7\ Steel, Robert G.D. and James H. Torrie, ``Principles and
Procedures of Statistics: A Biometrical Approach,'' 1980, Second
Edition, McGraw-Hill, Inc.
---------------------------------------------------------------------------
We developed a statistical weight for each category of surveyed
facilities to extrapolate from those facilities we actually surveyed to
the larger sampling population of 884 facilities. The weight for each
surveyed facility in a category represents its relationship to the
total number of facilities in the category. For example, we surveyed 28
facilities from a category of 34 facilities; 63 facilities from a
category of 255 facilities; 13 facilities from a category of 99
facilities, etc. As a consequence, each of the 28 facilities sampled
from the category of 34 facilities represents 1.2143 facilities (34
÷ 28 = 1.2143); each of the 63 facilities sampled from the
category of 255 represents 4.0476 facilities (255 ÷ 63 =
4.0476); and each of the 13 facilities sampled from the category of 99
represents 7.6154 facilities (99 ÷ 13 = 7.6154), etc. These
numbers (1.2143, 4.0476, 7.6154, etc.) are the statistical weighting
values (or weights) to be applied to each facility in each of the 12
categories for analysis of the collected data (such as waste
quantities). For a detailed description of our statistical methodology
and stratification process, see ``Supporting Statement--Information
Collection Request for Paint Manufacturing Industry Waste Survey, Part
B'' which was submitted to the OMB as part of the ICR for review and
approval, and the listing background document available in the public
docket for this proposed rule.
e. Conducting The Survey and Analyzing The Results. Using this
stratified random-sampling scheme, we distributed the questionnaires in
February and March of 2000 to a total of 299 facilities out of the
sampling population of 884 from the Dun & Bradstreet database that we
identified as the potentially impacted paint manufacturing facilities
in the United States.
Of the 299 questionnaires we distributed, 292 facilities responded
to the questionnaires. We found that in 1998, 187 of the survey
respondents manufactured paint products of interest to this listing
determination. Thirty six of these 187 facilities identified themselves
as paint manufacturers, but in 1998 did not generate or dispose of any
of the waste residuals within the scope of the questionnaire because
they recycled or reused all paint residuals as feedstock in their
manufacturing processes.\8\ The other 151 manufacturing facilities
generated one or more of the waste residuals of concern. They provided
information on their waste generation and management practices. Most of
these 151 manufacturing facilities also reused their waste residuals
on-site to some extent, either as feedstock in the paint production or
as an ongoing cleaning solution. The remaining respondents identified
themselves as either a paint sales agent, a non-paint manufacturer, a
non-paint manufacturer until after 1998, no longer a paint
manufacturer, or a paint-related manufacturer not under the scope of
the questionnaire. Table II.H.-1 provides a summary of the number of
potential paint manufacturing facilities selected from the Dun &
Bradstreet database, the number of facilities surveyed, the number of
facilities responded, and the number of paint manufacturing facilities
of interest found, in each category of facilities.
---------------------------------------------------------------------------
\8\ As stated in the questionnaire instructions, facilities were
not required to report on any of the residuals that are used
directly without reclamation as ingredients in manufacturing
processes to make new products; or used directly as effective
substitutes for commercial products; or returned directly to the
original process from which they are generated as a substitute for
raw feed stock. These residuals are excluded from the definition of
solid waste. See 40 CFR 261.2.
Table II.H.-1.--Summary of The Numbers of Potential Paint Manufacturing Facilities Selected, Surveyed, Responded
and Paint Manufacturing Facilities Found
----------------------------------------------------------------------------------------------------------------
Number of
selected Number of Number of
Dun & randomly Number of within-scope
Facility category Bradstreet sampled survey paint
facilities facilities respondents manufacturers
in in category in category found in
category category
----------------------------------------------------------------------------------------------------------------
Large, 2851-01, and TRI................................... 2 2 2 2
Medium, 2851-01, and TRI.................................. 0 0 0 0
Small, 2851-01, and TRI................................... 6 6 6 6
Large, 2851-01, and non-TRI............................... 34 28 28 17
Medium, 2851-01, and non-TRI.............................. 62 48 47 42
Small, 2851-01, and non-TRI............................... 379 77 75 44
Large, 2851-02, and TRI................................... 0 0 0 0
Medium, 2851-02, and TRI.................................. 0 0 0 0
[[Page 10072]]
Small, 2851-02, and TRI................................... 7 7 7 7
Large, 2851-02, and non-TRI............................... 23 22 22 14
Medium, 2851-02, and non-TRI.............................. 47 34 34 24
Small, 2851-02, and non-TRI............................... 324 75 71 31
-----------------------------------------------------
Total number of facilities............................ 884 299 292 187
----------------------------------------------------------------------------------------------------------------
We believe the Dun & Bradstreet database properly represents the
paint manufacturing universe (notwithstanding the database inevitably
includes some out-of-scope operations also listed under SIC 2851). We
used sound, widely accepted statistical methods to construct our
stratified random-sample covering the variety of paint manufacturing
types, paint production wastes, and waste management practices of
interest to this listing determination. Therefore, we believe the
survey results are representative of the paint manufacturing facilities
in the sampling population as well as the universe of paint
manufacturers of interest. Furthermore, based on our sample quality
review, data analysis, and intensive follow-up with survey respondents,
we believe that the data collected from the 187 survey respondents are
valid and reliable. Nevertheless, we specifically request data with
which to evaluate our assumption that the Dun & Bradstreet database
properly represents the paint manufacturing universe, as well as
comments on our approach to sampling and extrapolation of sampling
results.
We used survey data in three forms: (1) Direct survey responses
representing only the surveyed population; (2) weighted data to
extrapolate to the sampling population; and (3) data extrapolated to
the universe of paint manufacturing.
We used survey responses directly when data extrapolation to the
sampling population or the paint universe would not be necessary, such
as the patterns of waste management practices (see Section III.D).
As previously discussed, we derived independent weighting values
corresponding to the number of facilities represented by each surveyed
facility in each category. If the total quantities of a certain
residual generated by Category X facilities with a weight of 3.629 were
2,000 tons and by Category Y facilities with a weight of 8.8571 were
1,000 tons, and if facilities in the other categories did not report
any, then the combined residual quantities generated by the entire
sampling population of 884 can be calculated as 2,000 tons x 3.629 +
1,000 tons x 8.8571 = 16,115 tons. We used weighted waste quantities
or volumes to represent the waste volumes sent from each facility in
the sampling population to a particular management practice for input
to our national risk modeling analysis. See discussions in Sections
III.D and E.
Overall, 64% (i.e., 187 ÷ 292) of the 292 respondents are
paint manufacturing facilities of interest to this rulemaking.
Proportionally, there should be 566 paint manufacturing facilities in
the sampling population of 884 (from the Dun & Bradstreet database). As
explained earlier, because there is no comprehensive, single listing of
all paint manufacturing facilities, we relied on a number of data
sources to estimate that there are 972 paint manufacturers. This
estimate of 972 paint manufacturers in the universe was derived from
the total number of paint manufacturing facilities of interest (187)
found from the survey, by extrapolating through the percentages of SIC
2851 facilities in the Dun & Bradstreet database that are represented
by the 187 facilities. For a more detailed analysis, see the listing
background document in the public docket for this proposed rule.
To estimate the total waste generation by the entire population of
U.S. paint manufacturers (or universe), weighted data from the survey
(representing the quantities generated by the 566 paint manufacturing
facilities in the sampling population, as described above) is
extrapolated using a multiplier of 1.7173 (= 972 ÷ 566). For
example, if the total quantities of a certain residual generated by the
566 paint manufacturing facilities in the sampling population were
calculated as 16,115 tons, the universe waste quantities of this
residual would become 16,115 tons x 1.7173 = 27,674 tons. We used
such extrapolated universe waste quantities for our waste treatment and
management capacity analysis (see Section VI.E) and economic impacts
analysis (see Section IX.E). In general, these extrapolated figures
appear consistent with data in the Biennial Report System (see the
Economic Assessment in the docket for today's proposed rule).
f. Meeting Our Objectives for The Survey. We believe our
statistical stratified random-sampling survey collected data are
representative of the paint manufacturing industry in the United
States, and that the responses provided sufficient data for our use in
making this listing determination. We realize that uncertainties exist
in our survey. There is uncertainty in the exact number of the U.S.
paint manufacturing facilities. In addition, despite our quality
assurance reviews, there could still be data source or sampling errors
as in any other sampling or even census surveys. For instance, some
facilities might have entered inaccurate information inadvertently.
Nevertheless, we have used our best efforts to collect representative
data. By employing a statistically representative stratification/
categorization approach aimed at surveying all types of manufacturing
facilities and their waste streams, our unequal sampling survey (higher
percentages of facilities were surveyed for some categories of large
and medium facilities) actually enhanced the chance of identifying the
rare waste management activities practiced by the paint manufacturing
industry and in turn increased survey precision. This approach is
reasonable and an acceptable statistical tool to ensure the best
possible coverage.
Our subsequent statistical re-analysis of the questionnaire returns
indicated that we achieved satisfactory statistical probabilities for
finding a waste management activity used by one in 20 facilities. The
final probabilities
[[Page 10073]]
achieved are discussed in the listing background document in the public
docket for this proposed rule. In short, the probabilities achieved for
two categories of paint manufacturing facilities, 85% and 86.2%, were
under 90%, while the probabilities achieved for the other categories
ranged from 91.7% to 100%. More importantly, the survey successfully
captured a wide variety of intermediate and final waste management
practices of most interest as discussed in Section III.D. Therefore, we
believe we have made a reasonable effort to identify all management
practices and that we have met the objective of our sampling survey
designed for this listing determination.
III. Approach Used in This Proposed Listing
A. Summary of Today's Action
In listings promulgated by EPA, we typically describe the scope of
the listing in terms of the waste material and the industry or process
generating the waste. However, in today's rule we are proposing to use
the recently developed ``concentration-based'' approach for listing
paint manufacturing wastes. This approach was originally proposed for
wastes generated by the Dyes and Pigments industry (64 FR 40192 of July
23, 1999). In a concentration-based listing, a waste would be hazardous
unless a determination is made that it does not contain any of the
constituents of concern at or above specified levels of concern. This
approach draws from the concept of the toxicity characteristic to
define a hazardous waste based on concentration levels of key
constituents in the wastes. We describe this concept in detail later in
this notice.
We are proposing two hazardous waste listings for paint
manufacturing waste solids, K179 and for liquids, K180. If you generate
paint manufacturing wastes from tank and equipment cleaning operations
that use solvents, water, and/or caustic; emission control dusts;
wastewater treatment sludges; or off-specification product, as
specified in each listing description, you would need to determine
whether your waste contains any of the constituents of concern
identified for each listing at a concentration equal to or greater than
the hazardous concentration level set for that constituent. However,
the liquid K180 is a contingent listing. If your waste liquids are
managed exclusively in tanks or containers prior to discharge to a POTW
or under an NPDES permit, your waste would not be subject to the
listing, and you would not need to make a hazardous waste determination
for those wastes. We believe that under this proposed contingent
listing approach, the vast majority of waste liquids would not pose
unacceptable risks and would not be subject to the listing. The
approach is discussed in detail in Section IV. The proposed listing
descriptions are as follows:
K179--Paint manufacturing waste solids generated by
paint manufacturing facilities that, at the point of generation,
contain any of the constituents identified in paragraph (b)(6)(iii)
of this section at a concentration equal to or greater than the
hazardous level set for that constituent in paragraph (b)(6)(iii) of
this section. Paint manufacturing waste solids are: (1) Waste solids
generated from tank and equipment cleaning operations that use
solvents, water and/or caustic; (2) emission control dusts or
sludges; (3) wastewater treatment sludges; and (4) off-specification
product. Waste solids derived from the management of K180 by paint
manufacturers would also be subject to this listing. Waste liquids
derived from the management of K179 by paint manufacturers are not
covered by this listing, but such liquids are subject to the K180
listing. For the purposes of this listing, paint manufacturers are
defined as specified in paragraph (b) of this section.
K180--Paint manufacturing waste liquids generated by
paint manufacturing facilities that, at the point of generation,
contain any of the constituents identified in paragraph (b)(6)(iii)
of this section at a concentration equal to or greater than the
hazardous level set for that constituent in paragraph (b)(6)(iii) of
this section unless the wastes are stored or treated exclusively in
tanks or containers prior to discharge to a POTW or under a NPDES
permit. Paint manufacturing liquids are generated from tank and
equipment cleaning operations that use solvents, water, and/or
caustic. Waste liquids derived from the management of K179 by paint
manufacturers would also be subject to this listing. Waste solids
derived from the management of K180 by paint manufacturers are not
covered by this listing, but such solids are subject to the K179
listing. For the purposes of this listing, paint manufacturers are
defined as specified in paragraph (b) of this section.
Due to the uncertainties in our assessment of the management of
paint manufacturing waste liquids in surface impoundments, we are
seriously considering an alternative proposal not to list paint
manufacturing waste liquids. We describe this alternative and our
reasoning for this option later in this notice (see Section IV.D).
The following discussion describes the approach we are proposing if
K180 is listed.
If you generate any of these paint manufacturing wastes that you
currently believe are characteristically hazardous or subject to
another hazardous waste listing, you would still need to determine
whether your waste is a listed hazardous waste under K179 or K180
(unless as noted above you are not subject to K180 because your wastes
are managed exclusively in tanks or containers and then discharged to a
POTW or under an NPDES permit). We are proposing that all generators
could use knowledge of the waste to make an initial determination as to
whether any of the regulated constituents are present in the waste. If
you determine that none of the constituents are present in your wastes
at the point of generation, then you would have no further obligation
for determining whether or not your wastes are K179 or K180 listed
hazardous wastes (assuming the regulated constituents are in fact not
present in your wastes). If you determine that any of the constituents
are present in your waste, then we are proposing that you must either
use a two-tiered approach (see Section V.C for description) to
determine whether the constituent concentrations in your waste are
below the concentration levels in the listing or assume that your
wastes are hazardous at the point of generation. Under the proposed
two-tiered approach, if your total projected annual generation of paint
manufacturing waste solids is over 40 metric tons, and/or over 100
metric tons of paint manufacturing waste liquids, you would need to
test your wastes annually to determine whether concentration levels are
below the listing concentrations. If your wastes remained nonhazardous
for three consecutive years of testing and you have no significant
changes to your product and/or manufacturing or treatment processes,
the annual testing requirement would be suspended. If you made
significant changes to product and/or manufacturing or treatment
processes, the annual testing requirements would be reinstated. If your
projected annual waste generation is below these volumes, you would
have the option of either using knowledge of the waste or testing to
determine whether constituent concentrations are below the listing
concentrations. If any constituent is present at or above the
concentration level, then your waste is hazardous waste. We are
proposing that generators with annual waste generation exceeding 40
metric tons of solids and/or 100 metric tons of liquids keep limited
records on-site.
If your wastes meet the listing description, they would be subject
to all applicable RCRA subtitle C hazardous waste requirements,
including LDR requirements. This means that any characteristically
hazardous wastes or wastes hazardous under other listing codes (for
example F codes) that are determined to be hazardous under these
listings would also be subject to
[[Page 10074]]
treatment requirements for K179 and K180, in addition to any other
applicable treatment requirements.
There are several differences in the way the ``derived from'' rule
(40 CFR 261.3(c)(2)(i) would be applied to these wastes that have one
or more constituents above the proposed risk-based levels. Residues
from the treatment of solid K179 wastes are no long hazardous wastes if
their constituent concentrations are below the concentration levels for
K179. However, these treatment residues would still be subject to all
LDR requirements. As explained in Section IV, liquid K180 wastes,
however remain subject to the derived from rule. Also, the listing
descriptions make it clear that if a liquid is generated from the
onsite management of the solid K179 waste, it is no longer subject to
the K179 listing, rather it is subject to the K180 listing. If a solid
is generated from the onsite management of the liquid K180 waste, it is
no longer subject to the K180 listing, rather, it is subject to the
K179 listing. Once K179 or K180 wastes are sent offsite waste codes do
not change. These provisions are discussed in Section IV.F.
B. What Is a Concentration-Based Listing?
A concentration-based listing specifies constituent-specific levels
in a waste that cause the waste to become a listed hazardous waste. In
this proposed rule, we identify constituents of concern likely to be
present in solvent, water, and/or caustic cleaning residuals;
wastewater treatment sludges; emission control dust or sludges; and
off-specification products and which may pose a risk above specified
concentration levels. Using risk assessment tools developed to support
our hazardous waste identification program, we assessed the potential
risks associated with the constituents of concern in plausible waste
management scenarios. From this analysis, we developed ``listing
concentrations'' for each of the constituents of concern in the waste
categories listed above.
If you generate any paint manufacturing waste liquids or solids
addressed by this proposed rule, including any listed or
characteristically hazardous wastes, you would be required either to
determine whether or not your waste is hazardous or assume that it is
hazardous as generated under today's proposed K179 and K180 listings.
We are proposing that you must make a determination whether your waste
is a listed hazardous waste through process knowledge or by determining
representative concentrations for the constituents of concern in your
waste through sampling and analyses (depending on the volumes of
hazardous waste and nonhazardous waste within the scope of this listing
that you generate each year). You can use process knowledge to
demonstrate that the constituents of concern are not present in your
waste. Your waste would be a listed hazardous waste if it contains any
of the constituents of concern at a concentration equal to or greater
than the hazardous concentration identified for that constituent. The
detailed descriptions of the steps you would be required to follow to
implement the concentration-based listing are described later in this
proposed rule.
C. Why Is a Concentration-Based Approach Being Used for This Listing?
Thousands of constituents, also referred to as paint raw materials
or ingredients, are used in paint formulations.\9\ At the same time,
there are a number of chemicals that are very widely used in many
different types of paints. Because paints are produced in batch
processes that generally do not involve chemical reactions among the
raw materials, the finished paint and wastes consist of a mixture of
the different raw materials. Paint production wastes can also contain
constituents used for tank cleaning and other maintenance operations.
As a result, it is straightforward for a manufacturer to know what
constituents are likely to be present in his wastes.
---------------------------------------------------------------------------
\9\ Paint and Coating Raw Materials, 1996. Michael and Irene
Ash, Synapse Information resources, Gower Publishing Ltd, lists more
than 11,000 trade names and generic raw materials from 1300
manufacturers that are available for use in paints.
---------------------------------------------------------------------------
Taking these facts into account, a concentration-based approach to
listing paint production wastes as hazardous has a number of
advantages. We can use the approach to focus more narrowly on
ingredients that are likely to be widely used in paint formulations and
that are likely to pose risks to human health and the environment. A
concentration-based approach allows generators to evaluate the variable
wastes they generate individually for hazard, so only the truly
hazardous wastes are listed. This can place less burden on paint
manufacturers than a traditional listing that brings entire waste
streams into the hazardous waste system, regardless of the
characteristics of wastes generated by individual generators. The level
of any burden reduction depends on the costs of testing and the amount
and type of wastes generated by a given facility. This approach is
protective because it relies on concentration levels specifically set
to protect human health.
Finally, a concentration-based listing approach may provide an
incentive for hazardous waste generating facilities to modify their
manufacturing processes or treat their wastes. For example, if a
manufacturer has a listed hazardous waste based on constituent-specific
concentration levels established by EPA, he also knows that if the
concentration levels are reduced below the regulatory level due to raw
material substitution or process change, the waste would not be
regulated as listed hazardous waste. Therefore, the generator may
decide to substitute raw materials in order to generate a nonhazardous
waste (assuming that the waste does not carry any other listed or
characteristic hazardous waste codes). This approach encourages waste
minimization and reduced use of toxic constituents, goals of both RCRA
and the Pollution Prevention Act of 1990 (42 U.S.C. 13101 et seq., Pub.
L. 101-508, November 5, 1990).
RCRA, section 1003 states that one goal of the statute 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.
The Pollution Prevention Act of 1990 provides a hierarchy of
approaches. Pollution should be prevented or reduced; pollution that
cannot be prevented should be recycled or reused in an environmentally
safe manner; 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. If EPA provides a concentration-based
target in the listing, generators would have the regulatory and
economic incentive to meet the reduced levels.
Alternatively, we could have attempted to collect more information
on these specific wastes to support the traditional listing approach,
i.e., without any concentration limits. However, such a data collection
effort would have been difficult due to the large number of paint
production facilities, coupled with the wide variety of individual
paint products and the potential variability in waste characteristics.
Considering the
[[Page 10075]]
extensive sampling effort that this would require, and the relatively
small quantities of wastes produced by individual paint facilities, we
do not feel that such an effort was justified.
D. How Did the Agency Use the Survey Results for This Proposed Listing
Determination?
We used the 3007 survey data for several purposes: (1) To provide
the information for a general assessment of the paint and coating
industry's waste generation and management practices; (2) to identify
plausible waste management scenarios that are the basis for our risk
assessment and listing determination; and (3) to serve as the data
input for risk modeling parameters such as waste types and amounts sent
to specific management practices.
This section primarily addresses the survey results as a basis for
choosing plausible management scenarios for risk assessment and listing
determinations and for selecting data for input to our risk modeling
parameters. In addition, we used the survey data for our land disposal
restrictions treatment capacity analysis and for our economic impact
analysis discussed in sections VI and IX.
1. General Assessment of the Paint Industry's Waste Generation and
Management Practices
Our first step was to characterize the U.S. paint and coating
industry's generation and management practices. We considered a series
of questions, such as: how much waste was generated in 1998; of that
total, how much was RCRA hazardous waste and nonhazardous waste; what
types of waste were generated; and how were these wastes managed? Table
III.D-1 captures the weighted quantities of wastes within the scope of
this listing reported by facilities completing the 3007 survey. See
Section II.H for a discussion of the weighting process. With respect to
total amounts of waste generated our analysis showed the following:
We extrapolated from our estimated 566 paint and
coating manufacturers in the sampling population of 884 to estimate
that there are 972 paint and coating manufacturers, as explained in
Section II, H(e). Out of these 972, we estimate that about 600
facilities annually generate about 107,000 metric tons of hazardous
and nonhazardous waste within the scope of this listing.\10\
---------------------------------------------------------------------------
\10\ Note that we used weighted waste quantities in our risk
assessments (explained in Section II.H(e)), because the weighted
quantities are directly derived from our survey data and we are more
certain these waste quantities represent the true distribution of
the sampled population.
---------------------------------------------------------------------------
About 36 percent of paint manufacturing wastes are
already RCRA hazardous wastes, while 64 percent are currently
nonhazardous.
A few paint manufacturers produce the majority of the
waste. Ten percent of manufacturers generating waste potentially
within the scope of this listing generate about 80 percent of the
total amount of waste; and two percent of the manufacturers generate
about 50 percent of the total waste. Approximately half of paint
manufacturers generate less than five metric tons of waste per year.
Paint manufacturers mainly generate five types of
nonhazardous waste liquids and waste solids: washwater cleaning
liquid, washwater cleaning sludge, wastewater treatment sludge,
emission control dust and off-specification product. As shown in
Table III.D-2, these five waste types account for over 99% of all
nonhazardous waste generated in 1998.
About 27 percent of the manufacturers do not generate
any waste--all their waste liquids and waste solids are recycled
back into paint production processes.
After a thorough review of the data and other general observations
about the paint industry generation and management practices, we
focused further analyses only on nonhazardous wastes. We believe that
this approach is appropriate because hazardous paint manufacturing
wastes are currently managed according to RCRA Subtitle C regulatory
controls. From our survey of the industry, we found that about 36% of
the paint manufacturing wastes were coded and managed as listed or
characteristically hazardous waste. The listed wastes typically carried
a code for solvent wastes (F001 through F005), and characteristic
wastes usually exhibited the characteristic of ignitability or
toxicity. Based on available data from the survey, we believe that
listed or characteristically hazardous waste are being properly managed
under RCRA. The data supplied voluntarily by survey respondents that we
have on constituent concentrations in wastes classified as nonhazardous
show that the concentrations of TC constituents are well below the TC
levels. By narrowing the scope of our analysis to include only
nonhazardous wastes, we were able to concentrate risk assessment and
subsequent listing decisions on the wastes that may not already be
managed in a way that adequately protects or minimizes threats to human
health and the environment. However, this proposed listing would apply
to any paint manufacturing waste generated by the paint manufacturers
from tank and equipment cleaning operations that use solvents, water
and/or caustic; emission control dust; waste treatment sludges and off-
specification production waste regardless of how the waste has been or
is currently being managed.
Table III.D-1.--Paint Manufacturing Wastes Generated in 1998
----------------------------------------------------------------------------------------------------------------
Paint manufacturing waste category
-------------------------------------------------------------------------------
Weighted waste quantities Water and/ Emission
(metric tons) Solvent or caustic Wastewater control Off-
cleaning cleaning treatment dust/ specification Total
waste waste sludge sludges product
----------------------------------------------------------------------------------------------------------------
Hazardous....................... 18507 1047 0 39 3029 22622
Nonhazardous.................... 39 34098 1490 1972 1948 39547
Hazardous and Nonhazardous...... 18546 35145 1490 2011 4977 62169
----------------------------------------------------------------------------------------------------------------
[[Page 10076]]
Table III.D-2.--Nonhazardous Paint Manufacturing Waste Liquids and
Solids Generated in 1998
------------------------------------------------------------------------
Weighted
waste
quantity
(metric
tons)
------------------------------------------------------------------------
Nonhazardous Waste Liquids:
Solvent Cleaning Liquid.................................. 4
Washwater Cleaning Liquid................................ 31,036
Caustic Cleaning Liquid.................................. 66
------------
Total Nonhazardous Liquids............................. 31,106
============
Nonhazardous Waste Solids:
Solvent Cleaning Sludge.................................. 35
Washwater Cleaning Sludge................................ 2990
Caustic Cleaning Sludge.................................. 6
Wastewater Treatment Sludge.............................. 1490
Emission Control Dust.................................... 1972
Emission Control Sludge.................................. 0
Off-Specification Product................................ 1948
------------
Total Nonhazardous Waste Solids........................ 8441
------------------------------------------------------------------------
2. Management Scenarios Currently Used at Paint Facilities and Our
Selection of Waste Management Scenarios for Risk Assessment Modeling
This section summarizes our findings and conclusions concerning
current paint manufacturing practices for nonhazardous waste
management; the plausible waste management scenarios that we chose to
model for the risk assessment; and why we did not model certain
management practices. We also explain how we selected survey data from
waste types and quantities going to specific management practices for
risk modeling parameters. This entire section presents weighted survey
data (See Section II.H(e)), unless otherwise noted. We believe that the
weighted data that is derived from the responses of the estimated 566
paint manufacturing facilities most closely represents the distribution
of actual paint facility waste quantities managed at individual waste
management units at the 884 facilities in the sampling population,
which we assume are representative of the universe of affected paint
manufacturers. Table III.D-2 summarizes non-hazardous waste liquids and
solids generation.
We chose to model four waste management scenarios based upon our
review of the current waste handling practices reported in the survey
and the plausibility that these scenarios represent actual practices
that are used or could be used by the paint industry for disposal of
paint manufacturing wastes. The scenarios that we chose are waste
solids disposed in industrial nonhazardous waste landfills; waste
liquids stored and treated in off-site tanks at centralized wastewater
treatment facilities (CWTs) prior to discharge to a POTW or under a
NPDES permit; waste liquids disposed in surface impoundments at CWTs;
and, waste liquids stored and treated in tanks on-site at paint
manufacturing facilities prior to discharge to a POTW or under a NPDES
permit. The general criteria for selection of plausible waste
management scenarios and the rationale for choosing each of these four
scenarios is described in this section.
a. Plausible Waste Management Selection Criteria and Modeling
Considerations. Our regulations at Sec. 261.11(a)(3)(vii) require us to
consider the risk associated with ``the plausible types of improper
management to which the waste could be subjected'' because exposures to
wastes (and therefore the risks involved) will vary by waste management
practice. The choice of which ``plausible management scenario'' (or
scenarios) to use in a listing determination depends on a combination
of factors which are discussed in general terms in our policy statement
on hazardous waste listing determinations contained in the proposed
Dyes and Pigments Listing Determination (59 FR 66072, December 22,
1994). We have applied this policy in several previous listings and,
with some specific modifications that reflect unique characteristics of
the paint industry, believe it is appropriate to apply it here.
Our approach to selecting waste management scenarios to model for
risk analysis is to examine current industry management practices;
assess whether or not other practices are available to the industry;
and to decide what the industry would reasonably be expected to use.
There are common waste management practices, such as landfilling, which
we generally presume may be plausible for solid wastes and which we
will evaluate for potential risk. There are other practices which are
less common, such as land treatment, where we consider them plausible
only where the disposal methods have been reported to be practiced.
Where a practice is actually reported in use, that practice is
generally considered ``plausible'' and may be considered for potential
risk. In some situations, potential trends in waste management for a
specific industry suggest we will need to project ``plausible''
management even if it is not currently in use in order to be protective
of potential changes in management and therefore in potential risk. We
then evaluate which of these current or projected management practices
for each waste stream are likely to pose significant risk based on an
assessment of exposure pathways of concern associated with those
practices.
To model plausible waste management practices in the paint
industry, we used the individual waste quantities going from the
surveyed facilities to a particular type of management unit. This data
was used in a national risk modeling analysis to capture the range of
waste quantities from all facilities in the sampling population sent to
a particular type of waste management unit (the weighted waste quantity
distribution). Each waste quantity in the weighted distribution has a
weighting factor that represents the number of facilities in the total
sampling population that send a particular waste to a particular waste
management unit. We do not analyze the total quantity of wastes (i.e.,
the total universe waste generation data) going into a single waste
management unit because this scenario never occurs. As discussed later
in this section, when we found evidence that multiple waste streams
from a single facility or wastes from more than one facility are sent
to the same management unit, we added those quantities to ensure that
we accurately reflect the individual and combined quantities of paint
manufacturing wastes that are sent to a single management unit.
(Section III.D.2(c), below explains the methodology we used to compile
the survey data for input to the risk assessment models.)
EPA estimates that in 1998, the 884 facilities in the sampling
population generated 8,441 metric tons of nonhazardous waste solids and
31,106 metric tons of nonhazardous waste liquids. As would be expected,
wastes generated from paint production batches are also generated in
batches rather than in a continuous stream. Generally, the waste
quantities associated with each batch are relatively small, so that
these smaller quantities are aggregated and added into containers or
tanks as each new batch is produced. Liquid wastes are added into
liquid wastes and solid wastes are added into solid wastes, so that a
variety of waste types (for example sludges from tank cleaning
operations and wastewater treatment) may be combined and sent off to
one waste management unit. At the same time, some waste types are
managed separately, if for example they have some value for fuel
blending, rather than simply being sent off to land disposal or
wastewater treatment and discharge. We were able to distinguish
[[Page 10077]]
these management practices from the survey data.
One final note, before looking at solid and liquid wastes
separately. The total waste quantities that are accounted for in all of
the management practices that we discuss are not equivalent to the
total waste generation quantities. We believe there are several reasons
for this. First, because of the way the survey was structured, we were
not able to obtain an absolute balanced accounting of waste generation
and waste management from each facility. Some of the discrepancy
reflects waste management situations that may span one year to the
next, e.g., when a facility accumulates waste over a longer time period
before sending it on to disposal. Second, some wastes (or residuals)
may be accumulated for a time, and then recycled back into the
manufacturing process instead of being disposed. Third, there may be
some undetected reporting errors in the database. In any event, the
discrepancy between waste quantities generated in 1998 and waste
quantities disposed in 1998 is not significant for risk assessment
purposes. In the risk assessment, we use a distribution of individual
waste quantities actually sent to management scenarios as input to the
model, not national total waste quantities. The distribution of
individual waste quantities would not be significantly affected by the
discrepancy between wastes volumes generated and waste volumes
disposed.
Before we proceed to the technical discussion of our rationale for
choosing certain modeling scenarios and parameters, we will briefly
explain why we chose to structure these discussions as they are
presented in this preamble. We estimate that the 884 facilities in the
sampling population disposed of 44,278 metric tons of nonhazardous
waste solids and waste liquids in 1998 as shown in Tables III.D-3 and
III.D-4. These tables show that the disposal destinations, as would be
expected, are different for the waste solids and the waste liquids. The
same four waste solids that comprised the majority of the nonhazardous
waste solids generated in 1998 have very similar waste management
patterns. In contrast, the largest quantity of waste liquid generated
in 1998, washwater cleaning liquid is managed differently from the
solids and almost entirely through discharge to off-site public and
private wastewater treatment facilities. For these reasons, we split
our analysis of the waste solids and waste liquids. It was clear that
risk modeling for these two types of wastes would differ, therefore it
seemed reasonable to analyze the waste management patterns for them
separately.
b. Selection of Waste Management Scenarios for Risk Assessment
Modeling of Nonhazardous Paint Manufacturing Waste Solids. Table III.D-
3 lists the estimated weighted quantities of each type of nonhazardous
waste solid going to each management practice for the 884 facilities in
the sampling population. The total amount of waste solids disposed in
1998 was 8,226 metric tons (weighted). Of these 8,226 metric tons,
8,152 metric tons is made of the same four waste solids that comprised
the majority of solid waste generated in 1998: off-specification
product, emission control dust, washwater cleaning sludge and
wastewater treatment sludge. We estimate that the major portion of
these four solid waste streams, 6,926 metric tons, is disposed in
Subtitle D municipal and industrial landfills (nonhazardous landfills).
These 6,926 metric tons includes 942 metric tons of off-specification
product, 1,947 metric tons of the emission control dust, 1,440 metric
tons of wastewater treatment sludge and 2,597 metric tons of washwater
cleaning sludge disposed in 1998. In addition, 35 metric tons of
solvent sludge goes to nonhazardous landfills. The remaining 1,300
metric tons of waste solids disposed in 1998 go to Subtitle C
landfills, fuel blenders, CWTs, waste piles, incinerators, cement
kilns, boilers and industrial furnaces and ``other'' management units.
Note that tanks and containers are intermediate storage and treatment
units and their waste quantities are not counted in the total 8226
metric tons disposed in 1998.
Table III.D-3.--Nonhazardous Waste Solids Management
--------------------------------------------------------------------------------------------------------------------------------------------------------
Waste solids types (weighted quantities in metric tons)
------------------------------------------------------------------------------------------
Waste mgt. units Emission Emission Wastewater Washwater Caustic Solvent
Off-spec. control control treatment cleaning cleaning cleaning
product dust sludge sludge sludge sludge sludge
--------------------------------------------------------------------------------------------------------------------------------------------------------
Subtitle D/MLF............................................... 942 1947 0 1440 2597 0 35
Subtitle C................................................... 80 9 0 0 352 0 0
On-site S. tank.............................................. 53 0 0 0 1814 0 0
Off-site S. tank............................................. 0 0 0 0 0 0 0
On-site Trt. tank............................................ 0 1066 0 487 0 0 0
Fuel Blending................................................ 352 0 0 21 4 0 0
POTW......................................................... 0 0 0 0 0 0 0
WWTF......................................................... 48 0 0 5 0 0 0
NPDES........................................................ 0 0 0 0 0 0 0
INC.......................................................... 72 5 0 24 50 6 0
Cement Kiln.................................................. 56 0 0 0 0 0 0
BIF.......................................................... 3 0 0 0 0 0 0
Container.................................................... 2023 3052 0 992 1154 6 2
Waste Pile................................................... 0 0 0 0 0 0 33
Other........................................................ 133 11 0 0 1 0 0
------------------------------------------------------------------------------------------
Totals**................................................. 1686 1972 0 1490 3004 6 68
--------------------------------------------------------------------------------------------------------------------------------------------------------
**Total of each waste solid disposed in 1998 includes all disposal types except tanks and containers. The tanks and containers are considered
intermediate handling, not final disposal destination steps.
Note: The bolded numbers within the table are those that were used to derive the totals for each column.
MLF=Municipal Landfill
On-site S. tank=On-site Storage tank
Off-site S. tank=Off-site Storage tank
On-site Trt. Tank=On-site Treatment tank
NPDES=National Pollutant Discharge Elimination System
INC=incinerator
[[Page 10078]]
BIF=Boiler & Industrial Furnace
POTW=Publicly Owned Treatment Works
WWTF=Wastewater Treatment Facility
Based on this information, we chose to model disposal of waste
solids in industrial nonhazardous landfills. This is a common disposal
practice for a large portion of the waste solids disposed in 1998.
There are only two differences in modeling assumptions for industrial
nonhazardous landfills as compared to municipal landfills. Industrial
nonhazardous landfills are slightly smaller than municipal landfills so
the quantities of paint manufacturing waste modeled in the industrial
landfill are a relatively larger proportion of the total waste
quantities going into the unit. Also, industrial nonhazardous landfills
are not assumed to have daily cover. Both of these add to the
conservatism of the protective constituent levels predicted by the risk
assessment. For our inputs to the risk modeling, we used quantities of
off-specification product, emission control dust, wastewater treatment
sludge, washwater cleaning sludge and solvent sludge sent to
nonhazardous landfills. We did not include the small volume of caustic
cleaning sludge because they were incinerated and they were not
disposed in nonhazardous landfills. Emission control sludge was not
included either because it was not generated by any of the survey
respondents in 1998. The risk assessment in Section III.E, contains
more details about the methodology of the risk modeling process.
At the outset of our analysis of the survey data, we did not
believe that a landfill was a logical disposal destination for off-
specification product. We further investigated the disposal information
for off-specification product and decided that it should be in our
waste solids quantity distribution for risk assessment. We contacted
the eleven facilities that reported generating off-specification paint.
Nine of the eleven facilities stated that they sent only dried paint
wastes to nonhazardous landfills. The tenth facility reported sending
7.5 metric tons of mostly dried paint and paint flakes with small
amounts of liquid paint wastes to landfills. The eleventh facility
reported sending 14.7 metric tons of off-specification product of
unknown physical characteristics to nonhazardous landfills in 1998. We
chose to model off-specification product with waste solids sent to
nonhazardous landfills because large quantities (920 out of 942 metric
tons) of this waste are in dry form when sent to nonhazardous
landfills. Also, Municipal Solid Waste landfills have a prohibition on
disposal of liquids and we believe that the majority of commercial
industrial landfills do also (according to a 1995 EPA report ``State
Requirements for Industrial Non-Hazardous Waste Management
Facilities,'' 28 states restrict the placement of liquids in industrial
nonhazardous waste landfills).
The survey data contained information about four types of waste
management practices for waste solids that we chose not to model. The
first of these is treatment of solvent sludge in a waste pile. One
facility reported using a waste pile as an intermediate waste
management step for 33 metric tons of solvent sludge. Based on further
discussion with the facility contact, we determined that this waste was
a free flowing slurry that was piled on cardboard boxes inside a
containment building to dry and then disposed in a nonhazardous
landfill. We chose not to model this scenario because the waste is
managed in a closed facility. It is not open to airborne wind transport
and does not involve placement directly on the land. The remaining
solidified waste is disposed in a nonhazardous landfill.
Another type of waste management that we did not model is
combustion in incinerators, cement kilns, and boilers and industrial
furnaces. In past listing determinations where we have attempted to
assess risks from incineration, we found that the potential risks from
the release of constituents through incineration would be at least
several orders of magnitude below potential air risks from releases
from tanks or impoundments (see listing determination for solvent
wastes at 63 FR 64371, November 19, 1998). Further, it is difficult to
model what goes into combustion units in relation to the residual
constituents that are released from the combustion unit either in ash
or air.\11\
---------------------------------------------------------------------------
\11\ While other products of incomplete combustion may present
possible risks, it is difficult for us to assess this potential for
the chemicals of concern, especially for the likely scenario of a
small volume of paint manufacturing wastes being treated with other
much larger volumes of organic wastes.
---------------------------------------------------------------------------
We also chose not to model solid wastes sent to fuel blenders. All
of the fuel blending facilities reported in the survey were located at
Subtitle C permitted facilities. Since these fuel blenders receiving
paint manufacturing waste solids are RCRA permitted, they must comply
with protective regulations regarding releases from RCRA units and from
the RCRA facility. Finally, for these units it is also difficult to
model what goes into the unit in relation to the residual constituents
that are released from the unit to the air.
One last category of management unit that we chose not to model is
the ``other'' category. For the waste solids reported in this survey,
``other'' encompassed a variety of waste management types. The total
145 metric tons of waste solids handled in ``other'' management units
can be divided into four categories: Wastes that are disposed off-site
at waste treatment facilities, wastes that are reworked back into the
paint process, wastes that are sold to other companies and wastes sent
for precious metal recovery. Sixty-nine (69) metric tons of off-
specification product and emission control dust were sent to off-site
waste treatment and disposal facilities. Nine metric tons were treated
on-site and then sent to a Subtitle C landfill. Fifty-nine (59) metric
tons of off-specification product and emission control dust were
reworked back into the paint process on-site. Small quantities of off-
specification product and emission control dust totaling 3.5 metric
tons were sold to other companies who were not concerned about the
quality of the paint manufacturing waste for the manufacture of a new
product or the resale of a low grade paint. Less than one metric ton
(0.7) of emission control dust was sent to an off-site precious metal
recovery facility for recovery of the silver in the paint manufacturing
waste. Three metric tons of waste solids out of the 145 metric tons is
emission control dust that was reported to be released to the air from
pollution control devices that were not functional. The remaining one
metric ton of washwater cleaning sludge was sent to an off-site waste
treatment facility. We chose not to model any of these scenarios
because the scenarios we did decide to evaluate were likely to be the
riskier scenarios and over half of these wastes going to ``other''
units were either being reworked into the paint process or used for
manufacture of other products.
The paint manufacturing industry recycles several of its waste
streams. One of these streams is air emissions control dust. Sometimes
this material is used on-site in the formulation of low-grade paint, or
sent off-site to other
[[Page 10079]]
paint manufacturers for the same purpose (in neither case is
reclamation involved). In either case, the dust would not be considered
a solid waste because it is used or reused as an ingredient in an
industrial process to make a product pursuant to 40 CFR 261.2(e)(I)).
The dust contains valuable raw materials that are required to make
paint products. We have therefore not included these recycled dusts
when modeling our waste disposal scenarios. The Agency also notes that
this practice appears to be a form of legitimate recycling because
paint (even low-grade paint) must always meet certain specifications to
be usable. Recycled dust would only be added if it served as a required
ingredient in the paint.
Another method of recycling air pollution control dust involves
sending the materials off-site for recovery of precious metals (e.g.,
gold, silver, platinum). These materials would be considered solid and
hazardous wastes if they exhibit the toxicity characteristic for
metals, or if they exceeded the concentration levels in today's
proposed listing. Under those circumstances, they would be subject to
the reduced regulatory requirements of 40 CFR 266.70. However, EPA has
chosen not to include these materials in our waste disposal scenarios
because we believe that their inherent economic value would ensure
careful handling, thereby greatly minimizing the risk of releases. See
the 1985 rationale for the special regulatory regime for precious metal
reclamation (50 FR614, 648-49 (January 4, 1985)).
c. Selection of Waste Management Scenarios for Risk Assessment
Modeling of Nonhazardous Paint Manufacturing Waste Liquids. EPA
estimates that the 884 paint manufacturing facilities in the sampling
population disposed of 36,052 metric tons (weighted) of waste liquids
in 1998. Over 99% of this amount is washwater cleaning waste. A very
small amount of solvent cleaning and caustic cleaning liquids make up
the remaining 69 metric tons. Table III.D-4 shows how the 36,052 metric
tons of nonhazardous waste liquids were disposed in 1998.
The predominant destinations for washwater cleaning liquids are
POTWs and CWTs. About 27,625 metric tons of washwater cleaning liquid
go to POTWs and 6407 metric tons go to CWTs. Some of the 27,625 metric
tons of washwater cleaning liquid is directly discharged to POTWs, but
a significant portion is stored and treated on-site prior to being sent
to the POTW. Fourteen thousand five hundred thirty (14,530) metric tons
of washwater cleaning liquids are managed in on-site storage tanks and
7487 metric tons of washwater cleaning liquids are managed in on-site
treatment tanks. These tanks are the intermediate storage and treatment
units for almost all of the washwater cleaning liquids going to POTWs,
CWTs and the remaining waste management categories where these liquids
are disposed. The survey results indicated that about 17,000 metric
tons of washwater cleaning liquids are directly discharged by paint
facilities to POTWs. The remainder of the washwater cleaning liquids
(10,000 metric tons) that are sent to POTWs are stored or treated in
on-site tanks prior to discharge to the POTW. One facility directly
discharges 76 metric tons of washwater cleaning liquid under a NPDES
permit. These NPDES and POTW point source discharges that are subject
to regulation under Section 402 of the Clean Water Act are excluded
from the RCRA statutory definition of solid waste and therefore are not
subject to RCRA regulation. See 42 U.S.C. 6903(2) and 40 CFR 261.4(a)2.
However, while the liquids are being collected, treated or stored they
are subject to RCRA regulation. This also applies to any sludges
derived from the storage or treatment of the liquids.
Another destination for washwater cleaning liquid is offsite
storage and treatment tanks at CWTs. About 6407 metric tons of
washwater is sent to CWTs for treatment and then discharged to POTWs or
under a NPDES permit. The volumes of washwater liquid are probably
stored and treated in offsite tanks as our survey data showed that they
are onsite.
``Other'' management units receive 1309 metric tons of washwater
cleaning liquids. Five hundred sixty-three (563) metric tons of
washwater cleaning liquid goes to fuel blending units, incinerators and
cement kilns. A very small amount of washwater cleaning liquid, 3
metric tons was sent to nonhazardous landfills in 1998.
The other two waste liquid streams, solvent cleaning and caustic
cleaning liquid are disposed at fuel blending facilities and at POTWs,
respectively. POTWs received about 32 metric tons of caustic cleaning
liquids and fuel blenders received 4 metric tons of solvent cleaning
liquid in 1998. Sixty-one (61) metric tons of caustic cleaning liquid
is stored or treated in on-site tanks and an additional 33 metric tons
is managed in ``other'' units.
Based on these facts, we chose several modeling scenarios. The
first of these was the off-site storage of washwater cleaning liquids
in uncovered tanks at CWTs. About 18% of the yearly total of washwater
cleaning liquid disposed goes to CWTs. Another scenario we modeled was
the onsite treatment of washwater in tanks prior to discharge to a POTW
or under a NPDES permit. We also chose to model the on-site treatment
of washwater cleaning liquids in tanks because a significant amount of
liquids are handled in on-site tanks. This modeling scenario should
account for any exposure to washwater cleaning liquids and sludges
being treated in on-site tanks that are subsequently disposed through a
POTW or NPDES discharge.
We also chose to model waste liquids managed in an unlined surface
impoundment because we found one lined surface impoundment at a CWT and
we cannot, at this time, rule out the possibility that some quantities
of liquid paint manufacturing wastes may be managed in an unlined
impoundment which would present greater risks of release to the
environment. Survey respondents did not report any on-site impoundments
for management of liquid wastes. However, because we know that waste
management in surface impoundments, and particularly in unlined
impoundments, could pose significant risk, we chose to look for other
plausible scenarios that might involve impoundments.
Table III.D-4.--Nonhazardous Waste Liquids Management
------------------------------------------------------------------------
Waste Liquid types (weighted
quantities in metric tons)
--------------------------------------
Waste mgt. units Washwater Caustic Solvent
cleaning cleaning cleaning
liquid liquid liquid
------------------------------------------------------------------------
Subtitle D/MLF................... 3 0 0
Subtitle C....................... 0 0 0
On-site S. tank.................. 14530 33 0
[[Page 10080]]
Off-site S. tank................. 1 0 0
On-site Trt. tank................ 7487 28 0
Fuel Blending.................... 455 0 4
POTW............................. 27625 32 0
WWTF............................. 6407 0 0
NPDES............................ 76 0 0
INC.............................. 56 0 0
Cement Kiln...................... 52 0 0
BIF.............................. 0 0 0
Container........................ 1517 0 4
Waste Pile....................... 0 0 0
Other............................ 1309 33 0
--------------------------------------
Totals**..................... 35983 65 4
------------------------------------------------------------------------
** Totals for each column are derived from addition of all the bolded
numbers in each column. This total includes all disposal types except
tanks and containers, these are considered intermediate handling, not
final disposal destination steps.
Note: The bolded numbers within the table represent the quantities of
disposed waste that were summed to calculate the total waste disposed
for each waste type.
MLF=Municipal Landfill
On-site S. tank=On-site Storage tank
Off-site S. tank=Off-site Storage tank
On-site Trt. Tank=On-site Treatment tank
NPDES=National Pollution Discharge Elimination System
INC=incinerator
BIF= Boiler & Industrial Furnace
POTW=Publicly Owned Treatment Works
WWTF=Wastewater Treatment Facility
In other listing determinations, we have found management in
surface impoundments for a number of waste streams, although on-site
impoundments are more often associated with industries managing larger
quantities of liquids. As discussed above, a number of facilities send
their liquid waste to CWTs. These are the facilities that we believe
could plausibly be managing wastes in surface impoundments. We
contacted nine CWTs identified by survey respondents as receiving their
wastes to determine whether any of them employ impoundments as part of
their treatment processes. In fact, we found one facility that uses a
double-lined impoundment.
Twenty-one survey respondents indicated that they are sending
liquid waste to facilities they identified as wastewater treatment
facilities. Considering the universe of estimated 972 paint
manufacturers, we estimate that 4 or 5 other impoundments may be
receiving paint manufacturing wastes (see the listing background
document for this analysis). It may be reasonable to assume that
management of paint manufacturing wastes in an unlined surface
impoundment may occur. Therefore, we assumed this is a plausible
management scenario that we modeled for our risk assessment. Section
IV. D (proposed listing determination) contains additional discussion
concerning uncertainties associated with this scenario and discussion
of whether this is likely to be sufficiently rare that we should
consider an alternative approach.
Finally, we chose to model management of washwaters in on-site,
uncovered treatment tanks. Eight survey respondents reported that they
had uncovered on-site storage and treatment tanks. Volatile emissions
from the hazardous constituents contained in the washwater cleaning
liquids could be released into the air from these uncovered tanks.
Therefore we also chose to model management of waste liquids in
uncovered on-site treatment tanks because treatment tanks represent a
more conservative modeling scenario (higher air emissions from aerated
tanks) than storage tanks. We modeled the scenario of waste liquids
stored in uncovered storage tanks. We used the weighted quantities of
waste liquids (22,078 metric tons) reported in the survey as being
managed in on-site storage and treatment tanks.
There were five types of waste liquid management that we did not
choose to model. One of these management scenarios is the disposal of
washwater cleaning liquid in nonhazardous landfills. We contacted the
facilities that reported this practice and found that, in both cases,
the washwater cleaning liquid sent to the landfills was a liquid/solids
mixture. One facility reported that the mixture was filter pressed at
the landfill, the water portion was discharged to a POTW and the
remaining sludges were dried and disposed in a nonhazardous landfill.
The other facility reported that the liquid portion was incinerated and
the solids placed into a nonhazardous landfill. These scenarios are
not, therefore placement of liquids in a landfill. The next type of
waste liquids management that we did not model is the direct discharge
of washwater cleaning liquids to a POTW. RCRA regulation of waste
liquids that are stored or treated in tanks prior to discharge to a
POTW or under a NPDES permit is excluded under 40 CFR 261.4(a)(2), at
the permitted discharge point for the facility. The on-site storage,
collection and treatment of liquids and sludges generated from waste
liquids are however, subject to RCRA regulation. Another management
type that was not modeled is the combustion of washwater cleaning
liquids and caustic cleaning liquids in incinerators and cement kilns
or via fuel blending. In the previous section on waste solids we
explain the Agency's rationale for not modeling combustion
[[Page 10081]]
or fuel blending. That rationale applies equally to waste liquids.
The categories of ``other'' units reported for waste liquids that
we considered but did not select for modeling are: 541 metric tons of
washwater cleaning liquids reworked back into the paint process; 570
metric tons of washwater cleaning liquids treated on-site in tanks and
discharged to POTW and NPDES point sources; 51 metric tons of washwater
and caustic cleaning liquids stabilized on-site and sent to Subtitle C
landfills and 179 metric tons of washwater cleaning liquids sent to on-
site and off-site treatment units. The washwater cleaning liquids
reworked back into the paint process may not be in the scope of this
listing. However, our modeling of uncovered on-site treatment tanks
does estimate the risks from any of these washwater liquids that are
within the scope of the listing. The washwater cleaning liquids
reported under ``other'' that are discharged to a POTW should have been
reported as going to POTWs and included in that quantity of washwater
cleaning liquids. As explained earlier, the on-site treatment or
storage of any liquids being discharged to a POTW is covered by our
risk modeling of on-site treatment tanks. The washwater and caustic
cleaning liquids that are treated on-site and sent to a Subtitle C
landfill are also covered by our on-site treatment tank modeling. The
last group of ``other'' units (the 179 metric tons of waste liquids)
consists of 23 metric tons of washwater cleaning liquid sent for off-
site treatment and disposal; and 156 metric tons of on-site treatment
conducted in tank type units. The estimate of any risks posed from the
treatment of washwater cleaning liquids in these units should be
covered by our risk modeling of on-site treatment in tanks of washwater
cleaning liquids.
d. Survey Data as Input to Modeling Parameters. To conduct a risk
assessment for these wastes, we needed to assemble the survey data
associated with disposal of waste solids and waste liquids into our
chosen waste management units of concern: industrial nonhazardous
landfills, on-site tanks, off-site tanks and surface impoundments. The
specific data we used were the quantities of waste solids and waste
liquids sent by each facility to each of our four management units of
concern. We used these data as input to the modeling parameters in our
risk assessment. The risk assessment estimated the concentration of
individual constituents that could be present in each waste and remain
protective of human health and the environment. These risk based
constituent concentration levels in the waste streams are the levels
that can be managed in the waste streams and remain below a target
cancer risk level of 1 X 10-5 excess lifetime cancer risk
for individuals exposed to carcinogens in the waste streams and a
target hazard quotient (HQ) of 1.0 for individuals exposed to
constituents in the waste streams that produce noncancer health
effects.
We also needed to capture the distribution of waste quantities
going to individual waste management units. Once we determined that we
could represent paint manufacturing wastes as solids and liquids
disposed in nonhazardous landfills, on-site treatment tanks, off-site
wastewater treatment tanks and surface impoundments, we then developed
a methodology to assemble the waste quantity distributions for solids
and liquids sent from each facility in the sampling population to each
of these four types of waste management units. We used the individual
weighted quantities of waste solids sent to nonhazardous landfills to
compile the waste solids distribution and the individual weighted
quantities of waste liquids sent to tanks and surface impoundments at
offsite wastewater treatment facilities for the waste liquids
distribution. We considered several factors in developing the waste
quantity distributions including the total quantities of each
individual type of waste stream reported by the surveyed facilities,
whether any facilities that generate these wastes may produce
quantities of waste conditionally exempted under EPA regulations for
small quantity generators and whether any of the surveyed facilities
reported waste co-management scenarios.
First, we identified conditionally exempt small quantity generators
by combining the entire hazardous and nonhazardous paint manufacturing
waste solid and liquid quantities for all waste streams within the
scope of this listing generated by each surveyed facility. We compared
these quantities of waste to the amount specified in Sec. 261.5 (a),
the Conditionally Exempt Small Quantity Generator (CESQG) exclusion
criteria. This existing regulation excludes those facilities from
Subtitle C that generate no more than 100 kilograms per month of
hazardous waste or 1.2 metric tons per year. We separated the survey
data from the CESQG facilities because under the Federal RCRA
regulations, they could continue to send their small waste quantities
to nonhazardous disposal facilities. Including these very small waste
quantities in our risk modeling could inappropriately bias the modeling
results toward the higher protective constituent concentrations.
Therefore, it would be inappropriate to include these small volumes in
the risk modeling to develop the regulatory limits, since these wastes
would be excluded from the regulation. Also, including these small
volumes in the modeling would bias the results towards higher
protective limits because, all other things being equal, small volumes
result in lower estimated risk and therefore higher protective levels.
Further, even if all the CESQG facilities' wastes are hazardous, they
could continue to manage them in a municipal solid waste landfill, in
accordance with appropriate individual state requirements. Twelve
facilities reported that they generated less than 1200 kilograms per
year of hazardous and nonhazardous wastes combined. We did not use the
data for these 12 for any of the risk assessment modeling because the
generators of these conditionally exempt quantities could continue to
manage their wastes as they are currently managing them even if the
wastes were listed.
Next, we compiled separate waste quantity distributions for waste
solids and waste liquids. We also accounted for co-management scenarios
as reported in the survey responses. Co-management scenarios are: (1)
Waste solids or waste liquids generated at a single paint facility that
are disposed at the same off-site management unit, and (2) waste solids
or waste liquids from different paint facilities that are sent to the
same off-site waste management unit. Each of these combinations results
in larger paint manufacturing waste quantities being associated with
disposal at particular waste management units. We combined these
quantities for 14 waste solid co-management scenarios.
At this point, the waste solids quantity distribution consisted of
quantities of nonhazardous off specification product waste,
nonhazardous emission control dust, nonhazardous water/caustic sludge,
nonhazardous wastewater treatment sludge and nonhazardous solvent
sludge sent to nonhazardous landfills. All waste solid quantities from
any of the surveyed facilities that did not meet the conditionally
exempt small quantity generator exclusion were included. The waste
solids quantity distribution had 57 entries for single and co-managed
waste streams. In addition to this quantity distribution that combined
all the types of waste solids (combined waste solids), a second
quantity distribution was constructed that contained only nonhazardous
emission
[[Page 10082]]
control dust sent to nonhazardous landfills. The emission control dust
only distribution was constructed similarly to the manner in which the
combined solids quantity distribution was constructed. It did not
include the conditionally exempt small quantity generator facilities
data and co-management of wastes was considered. The emission control
dust only distribution was input into the risk model with an
accompanying low moisture content to represent a worst-case scenario
for wind blown materials that could be released from the nonhazardous
landfill.
We created three separate waste liquid distributions in the same
manner as the solids distributions to correspond to the modeling
scenarios for liquids. Initially, any CESQG facilities that generated
waste liquids were eliminated from consideration. The first waste
liquid distribution contained washwater cleaning liquid quantities sent
off-site to a CWT. We combined waste liquid quantities where we found
co-management scenarios. We used this quantity distribution to evaluate
washwater cleaning liquid stored in uncovered off-site tanks at CWTs.
Next, the surface impoundment waste liquid quantity distribution was
exactly the same as the distribution of all quantities of washwater
cleaning liquids that sent to off-site CWTs. Because surface
impoundments, when they exist, are a part of the CWT's treatment
process, we assumed that quantities of waste liquids sent off-site to
CWTs could be treated in unlined surface impoundments as well as in
tanks. The third liquids quantity distribution consists of the largest
washwater cleaning quantity reported in the survey. This single
quantity was used to conduct a conservative risk assessment screening
for exposure to emissions from waste liquids in uncovered on-site
treatment tanks.
To summarize, we assembled five separate quantity distributions
using the survey response information.
One distribution consisted of all the survey quantities
of nonhazardous combined waste solids from: nonhazardous solvent
cleaning sludge, nonhazardous washwater cleaning sludge,
nonhazardous waste water treatment sludge, nonhazardous emission
control dust and nonhazardous off specification product. This
distribution called, ``combined solids'' was used for risk analysis
as a sludge-like material in a nonhazardous landfill.
The second distribution consisted of all nonhazardous
emission control dust quantities only. This distribution was used
for risk assessment modeling as a dust-like material going to a
landfill.
The third distribution was a liquids distribution that
consisted of all nonhazardous liquid quantities of nonhazardous
washwater cleaning liquid that were disposed in off-site tanks at
CWTs. This liquids distribution was used for risk modeling of waste
liquids being sent to uncovered off-site treatment tanks.
The fourth quantity distribution was exactly the same
as the one above, but the target management unit was a surface
impoundment instead of a tank.
The last quantity used for modeling was a single
quantity, the highest washwater cleaning liquid quantity managed in
uncovered on-site treatment tanks as reported in the survey. This
was used to evaluate risks from waste liquids managed in on-site
storage and treatment tanks.
Each of these quantity distributions was used in the process of
modeling the risk to human and environmental receptors from the
disposal of waste solids and liquids in nonhazardous landfills, tanks
and surface impoundments. The next section describes the risk
assessment approach and process in detail.
E. What Risk Assessment Approach Did EPA Use to Determine Allowable
Constituent Waste Concentrations?
1. Which Factors Did EPA Incorporate Into Its Quantitative Risk
Assessment?
In making listing determinations, the Agency considers the listing
criteria required in 40 CFR 261.11. The criteria provided in 40 CFR
261.11 include eleven factors for determining ``substantial present or
potential hazard to human health and the environment.'' Nine of these
factors, as described generally below, are directly incorporated into
EPA's completion of a risk assessment for the waste streams of concern:
Toxicity (Sec. 261.11(a)(3)(i)) is considered in
developing the health benchmarks used in the risk assessment
modeling.
Constituent concentrations that pose a hazard to human
health are determined in the risk assessment
(Sec. 261.11(a)(3)(ii)).
Waste volumes (Sec. 261.11(a) (3)(viii)) are used to
define the initial conditions for the risk evaluation.
Potential to migrate, persistence, degradation, and
bioaccumulation of the hazardous constituents and any degradation
products (sections 261(a)(3)(iii), 261.11(a)(3)(iv),
261.11(a)(3)(v), and 261.11(a)(3)(vi)) are all considered in the
design of the fate and transport models used to determine the
concentrations of the contaminants to which individuals are exposed.
Finally, we consider two of the remaining factors,
plausible mismanagement as discussed in the previous section and
other regulatory actions as discussed in Section IV on the proposed
listing determinations ((Secs. 261.11(a)(3)(vii) and
261.11(a)(3)(x)) in establishing the waste management scenario(s)
modeled in the risk assessment.
EPA conducted analyses of the risks posed by the waste streams
evaluated for this listing to determine the concentrations of
constituents that if found in paint production wastes would meet the
criteria for listing set forth in 40 CFR 261.11(a)(3). This section
discusses the human health risk analyses and ecological risk screening
analyses EPA conducted to support our proposed listing determinations
for paint and coatings production wastes. We consider the risk analyses
in developing our listing decisions for each of the waste streams. The
risk analyses we describe in this section are presented in detail in
the Risk Assessment Technical Background Document for Paint and
Coatings Listing Determination which is located in the docket for
today's proposed rule.
2. How Did EPA Use Damage Case Information?
We also considered whether any damage cases exist that indicate
impacts on human health or the environment from improper management of
the wastes of concern, which is required under the listing regulations
(Sec. 261.11(a)(3)(ix)). Damage incidents might be useful in not only
establishing whether there was any impact on human health or the
environment from improper management, but such incidents might also
provide some information on plausible mismanagement practices, and on
the potential of the waste constituents to migrate, persist, or degrade
in the environment. We compiled damage incidents involving paint
production wastes and paint constituents, including paints disposed of
by non-paint manufacturing facilities. We found approximately 21
incidents that appear to involve the release of constituents from the
management of paint product wastes either at the site of paint
manufacture, or at off-site facilities. We also found damage incidents
for the disposal of paint wastes by end-users, and numerous other
possible incidents for which we did not have adequate information to
determine the type of facility or the nature of the waste involved. A
report summarizing the results of this search is in the docket for
today's rule (Damage Incident Compendium and Report, July 2000).
A number of the data sources contained information on potential
problems related to management or use of paint materials at a variety
of sites. The information of most potential utility came from the
Superfund Public Information System (SPIS). The SPIS contains data from
the Record of Decision System (RODS), which
[[Page 10083]]
document remediation actions as sites on the National Priority List
(NPL), and the Comprehensive Environmental Response Compensation and
Liability Information System (CERCLIS), which contains other
information on potential and actual Superfund sites. Information from
other sources proved to be less useful. For example, a search of the
Right-to-Know network database (RTK) provided some matches for paint as
a pollutant in the database of civil cases filed by the Department of
Justice on behalf of EPA, however these included violations of RCRA
permitting, storage, and reporting requirements, rather than disposal
problems, or violations of the CAA or CWA. The Defense Technical
Information Center database provided information on defense
installations on the NPL and slated for closing, however these appear
to be end users, not paint manufacturers.
EPA believes the damage cases have limited utility for determining
current plausible mismanagement scenarios. The vast majority of damage
cases (especially Superfund sites) were from sites that operated prior
to implementation of the current RCRA regulations, and generally
reflect management practices that no longer occur (such as an in ground
solvent pit, buried crushed drums and dumping liquids in trenches). We
believe these past damage incidents do not represent current waste
management practices by the paint manufacturing industry. This is
supported by the results from the 3007 Survey, which indicate that
manufacturers are coding and managing many wastes as hazardous,
especially some of those likely to have the greatest solvent content.
For example, all facilities that reported solvent cleaning wastes
reported them to be hazardous, except for one that was sent to fuel
blending. Therefore, we expect that waste management practices have
changed, since the promulgation of the RCRA regulations, including the
addition of a number of organics to the Toxicity Characteristic in 1990
and the listings for certain waste solvents (F001 to F005) in 1980 (and
as revised in 1985).
In most cases, the available damage incident data rarely indicated
the composition of the paint or paint manufacturing waste, nor the
source of the waste. Instead, the data depicted the material or waste
in general terms, such as ``paint,'' ``paint manufacturing waste,'' or
``sludges.'' Thus, the databases did not categorize the damage
incidents involving paint manufacturing wastes into the specific waste
categories of interest (solvent cleaning wastes; water/caustic cleaning
wastes; wastewater treatment sludge; emission control dust or sludge;
and off-specification production wastes) nor allow us to determine
concentrations above which paint manufacturing wastes could pose a
hazard. Thus we are unable to directly attribute contamination observed
from the mismanagement of paint manufacturing wastes to those the
wastes that are specifically addressed by this proposed listing.
Even if historical problems could be traced to paint materials,
they are not very useful in assessing the potential risks for paint
production wastes as they are currently generated. The damage incidents
may represent the potential for the migration, mobility, and
persistence of constituents in paint manufacturing wastes. The damage
cases do provide some anecdotal information in support of a conclusion
that some paint manufacturing wastes may yield environmental
contamination when managed in the ways that lead to the damage cases.
However, because the wastes in the damage cases may include wastes now
managed as hazardous, and because the cases may reflect management
scenarios we do not believe are currently common or plausible, it is
difficult to use them to reach conclusions as to which of the wastes
under evaluation in today's proposal may pose significant risks.
Certainly it is difficult to use damage cases to ascertain at what
concentration the paint manufacturing wastes under evaluation may pose
such risks. Thus, while the damage cases supports that some paint
manufacturing wastes may sometimes pose risks, EPA is relying upon its
quantitative risk assessment in formulating today's proposal.
3. Overview of The Risk Assessment
For a concentration-based listing, EPA is proposing to calculate
the concentration levels, or ``listing levels'' in the waste at or
above which a waste would be considered hazardous. Risk assessment is
used to identify the concentrations of individual constituents that can
be present in each waste stream and remain below a specified level of
risk to both humans and the environment.
To establish these listing levels, the Agency (1) Selected
constituents of potential concern in waste, (2) evaluated plausible
waste management scenarios, (3) calculated exposure concentrations by
modeling the release and transport of the constituents from the waste
management unit to the point of exposure, and (4) calculated waste
concentrations that are likely to pose unacceptable risk. In addition,
the EPA conducted a screening level ecological risk assessment to
ensure that the concentration limits were dually protective of human
health and ecological life.
The following sections explain the selection of constituents that
we evaluated in the risk assessment and present an overview of the
analysis the Agency used to calculate risk-based listing levels for
solvent cleaning waste, water and/or caustic cleaning waste, waste
water treatment sludge, emission control dust and sludges, and off-
specification product. You will find more details of how we selected
the constituents of concern in the Listing Background Document. Details
of the risk assessment are provided in the document in the docket
entitled Risk Assessment Technical Background Document for the Paint
and Coatings Listing Determination (hereafter called the Technical
Background Document).
4. How EPA Chose Potential Constituents of Concern
Our overall goal in choosing potential constituents of concern was
to identify commonly used, potentially hazardous constituents that
could pose unacceptable risk if present in mismanaged paint
manufacturing wastes. Waste sampling was not practical because we would
have had to conduct extensive sampling to adequately represent
thousands of variable products and constituents. As an alternative, we
chose to rely on published information and environmental databases to
select constituents of concern. We believe our review of the literature
available on paint formulation and manufacturing combined with our
search of specific databases provided representative information on
widely used raw materials. In addition, we selected constituents for
which we had access to toxicity and fate and transport data to conduct
a risk assessment for each potential constituent of concern. We
verified and supplemented these sources with information provided by
paint manufacturers when the 3007 survey data was available.
We used the following three-phased approach to develop a list of
potential constituents of concern. In the first phase, we developed a
preliminary list of potentially hazardous constituents in paint
formulations which we could readily evaluate for potential risks to
human health, and for which we have test methods to detect their
presence in waste. In the second phase, we narrowed the list to
constituents for which we would conduct a risk assessment. In the third
phase, we
[[Page 10084]]
added a limited number of constituents to the risk assessment, as
additional information became available.
a. Phase 1: How Did EPA Develop a Preliminary List of Constituents?
We developed a preliminary list of constituents in three steps: first,
out of the thousands of constituents that are used as ingredients in
paints, we identified a subset of potentially hazardous constituents
used in paint formulations; second, we identified those constituents
for which we have adequate data to complete a risk assessment so that
we could develop a protective concentration level for the listing, if
appropriate; finally, we ensured that test methods were available so
paint manufacturers would be able to identify the presence and
concentration of constituents in their wastes, as necessary.
Initially, we relied on the ``Database of Published Paint
Information'' (available in the docket), a computerized database that
characterizes paint raw materials. In particular, we used the ``Raw
Materials Module'' which contains information on the following types of
ingredients that are used to make paints (we believe that these
categories cover the vast majority of paint ingredients that could pose
a concern):
Additives--Inorganic and organic metal-containing raw material
additives such as driers (siccatives), catalysts, stabilizers.
Binders--Organic polymeric compounds used to adhere the pigment
particles and other paint ingredients into a film on the surface
being painted.
Biocides--Compounds used to kill microorganisms and larger
organisms such as insects. Categories of biocides include
insecticides, anti-fouling compounds (e.g., for use on ships),
fungicides, algaicides, and mildewcides.
Pigments--Insoluble particulates used to give the paint film
color as well as structured strength, as well as in some cases
imparting corrosion resistance or other properties to paint film.
Solvents--Solvents used both in traditional ``oil'' based
(solvent based) paints, as well as those solvents used in waterborne
paints.
The constituents in the ``Raw Materials Module'' were identified
from an extensive set of reference materials, including textbooks,
monographs, articles and Material Safety Data Sheets listed in the
``Bibliography of Documents Module'' of the database. We believe this
survey approach allowed us to identify constituents that are used in
paint formulations based on a variety of sources. We also emphasized
constituents we had reason to believe were more likely to pose a risk
to human health and the environment. (For example, we used other
governmental sources, such as a National Institute of Occupational
Safety and Health (NIOSH) document characterizing hazardous worker
exposures in paint manufacturing, as well as our experience in the RCRA
program dealing with a variety of hazardous and potentially hazardous
constituents.) In the fall of 1999, when we developed the preliminary
list of constituents, the Raw Materials Module contained approximately
500 constituents.
In developing the preliminary list of constituents, we also
considered other sources that might provide information on specific
constituents associated with paint manufacturing facilities. For this,
we turned to the Toxics Release Inventory (TRI) data base. Under the
Emergency Planning and Community Right-to-Know Act (EPCRA), all paint
manufacturing facilities with ten or more employees must report
chemical releases if they manufacture, process, or otherwise use any
EPCRA section 313 chemicals in quantities greater than the established
thresholds. Facilities must report the quantities of both routine and
accidental releases. Facilities are required to report quantities only
for individual constituents. In the 1997 TRI, a total of 646 facilities
in SIC code 2851 reported releasing 115 different constituents into the
environment. From these 115 constituents, we identified approximately
60 additional constituents that were not already in the ``Raw Materials
Database,'' but were associated with paint manufacturing facilities.
While TRI reports of constituent releases cannot be tied directly to
the five waste streams in the scope of this rule, TRI releases do tell
us that the constituents are used by paint manufacturing facilities,
released into the environment, and could potentially be found in the
waste streams of concern.
We recognize that the TRI data do not correlate perfectly to the
scope of facilities and wastes potentially covered by this listing. For
example, the SIC category also includes some facilities that are not
paint producers. Also, TRI tracks releases of specific constituents.
However, the TRI data do not distinguish whether the releases are
hazardous or non-hazardous wastes or whether the constituents are
present in a larger matrix with other materials. While TRI does not
contain sufficiently detailed information to associate releases
directly with paint production, it does provide the best available
information source on toxic constituent releases to waste management
units and environmental media from facilities within the appropriate
SIC code.
Our next critical step in identifying a preliminary list of
constituents was to determine which constituents we could readily
analyze for potential human health effects and which constituents could
be readily tested in wastes. We looked for the following:
Health benchmarks: values used to quantify a chemical's possible
toxicity and ability to induce a health effect. Benchmarks are also
specific to routes of exposure (ingestion or inhalation) and
duration of exposure.
Physical/chemical properties: information used to predict the
behavior and movement of constituents in the environment essential
to model environmental fate and transport.
Analytic methods: reliable methods available to test for the
presence of constituents at concentrations of concern in order to
implement a concentration based listing. We identified those
constituents that have available SW-846 analytic methods.
We found that of the constituents in the Raw Materials Module and
the constituents reported in the TRI, 114 had health benchmarks. We
then searched for data on physical/chemical properties and SW-846
analytic methods for each constituent. We finally had a list of 66
constituents with test methods and sufficient data to conduct further
analyses. We included the 66 constituents in the 3007 survey and asked
respondents to identify which constituents occurred in each of their
paint manufacturing waste streams. Table III.E-1 lists the 66
constituents.
Table III.E-1.--Candidate Constituents for Risk Assessment
------------------------------------------------------------------------
-------------------------------------------------------------------------
Acetone
Acrylamide and acrylamide derived polymers
Acrylonitrile and acrylonitrile derived polymers
Allyl alcohol
Antimony and compounds
Barium and compounds
Benzene
Benzyl alcohol
Butyl benzyl phthlate
Cadmium and compounds
Chloroform
Chromium and compounds
Cobalt and compounds
Copper and compounds
Cyanide
Cyclohexane
Dibutyl phthlate
3-(3,4__Dichlorophenyl-1)1 dimethylurea
Diethyl phthlate
Di (2-ethylhexyl) phthlate
2,4 Dimethylphenol
1,4 Dioxane
Ethyl acetate
Ethylbenzene
Ethylene glycol
Formaldehyde and formaldehyde-derived polymers
Isophorone
Lead and compounds
[[Page 10085]]
M-Cresol
Methanol
Methyl acrylate
Methylene chloride
Methyl ethyl ketone
Methyl isobutyl ketone
Methyl methacrylate and methyl methacrylate derivatives
2,2 Methylenebis (3,4,6-trichlorophenol)
Mercury and compounds
Molybdenum and compounds
M-Xylene
Naphthelene
N-Butyl alcohol
Nickel and compounds
Nitrobenzene
2-Nitropropane
O-Cresol
O-Xylene
P-Cresol
Pentachlorophenol
Phthalic anhydride
Phenol
Selenium and compounds
Silver and compounds
Styrene and styrene-derived compounds
Tetrachloroethene
Tin and compounds
Toluene
Toluene diisocyanate
1,1,1 Trichloroethane
1,2,4-Trichlorobenzene
Trichloroethene
2,4,6 Trichlorophenol
Vanadium and compounds
Vinyl acetate and vinyl acetate derived polymers
Vinylidene chloride and vinylidene chloride derived polymers
Xylene (mixed isomers)
Zinc and compounds
------------------------------------------------------------------------
b. Phase 2: How Did EPA Select Potential Constituents of Concern
for the Risk Assessment? Before we began our initial risk assessment
analyses in the fall of 1999, and before survey data were available, we
selected a subset of 34 constituents (from the 66) to use in developing
the risk assessment structure. We believe that it is important to
select toxic constituents that are likely to occur across a wider
variety of waste streams so that the concentration-based listing will
capture more wastes of concern. While it is possible that infrequently
occurring constituents could pose risks, we believe it is most
effective to address risks from constituents that could be associated
with more paint production wastes and occur in larger volumes. To
select these constituents, we looked for some indicators that could
give us insight into which were more widely used or more likely to
occur in wastes. We started with the 66 constituents identified in
Table 1 and looked at 1997 TRI data first to find constituent volumes
released to waste management units and environmental media. We then
looked at RCRA Biennial Reporting System (BRS) data to find how
frequently paint manufacturing facilities generated hazardous wastes
that contain each of the 66 constituents. ( Hazardous waste generators
are required to report biennially the listed and characteristic
hazardous wastes that they generate by waste code--the Biennial
Reporting System. Each hazardous waste code for listed or TC
characteristically hazardous wastes is associated with specific
hazardous constituents that are the basis of the listing.) We looked at
the number of paint manufacturing facilities that reported generating
hazardous waste codes associated with the specific constituents we were
interested in. While we know that these wastes are already hazardous,
we looked at these data as possible indicators of constituents that
might be associated with nonhazardous wastes at paint manufacturing
operations. We also considered TRI data for two reasons. First, TRI
``releases'' cover a broader range of materials than ``hazardous
wastes'' (in the BRS) and include non-hazardous wastes that are not
reported to BRS. Also, TRI data provide some indication of the relative
amounts or frequency that constituents may be released into the
environment.
First, we looked at TRI for the volume of releases of each
constituent from facilities in SIC 2851 to on-site landfills,
solidification/stabilization, wastewater treatment, and offsite
landfills and surface impoundments. We evaluated releases to these
units first, because, while we did not yet have the results of the
3007 survey, these management units correspond most closely to waste
management scenarios we generally address for listing purposes. We
initially identified a list of 20 constituents out of the 66 with
the largest volume releases to these management units.
Second, because solvents were heavily represented among the
first 20 constituents we identified from TRI data, we focused on the
remaining constituents that fell into other use categories, such as
pigments, binders, and biocides. We believe that it is important to
have a broader representation of other types of constituents,
besides solvents, which are used in paint formulations. (We note
that some constituents serve more than one purpose in paint
formulations.) We considered total TRI releases (including releases
to air, surface waters, etc., in addition to releases to the waste
management units listed above) for each of the remaining
constituents. We also looked at the number of RCRA facilities that
are likely to generate the constituent in hazardous waste, based on
BRS data. This resulted in adding 13 constituents, including all
eight remaining pigments, binders and biocides that had any TRI
releases and 5 that were only reported in the BRS.
Third, while we did not have TRI data available for two
additional constituents, cobalt and tin, we added them based on our
knowledge that they are commonly used as pigments in paints.
We initially identified 35 constituents that met our screening
criteria. However, we later dropped one of the 35 constituents
(phthalic anhydride) because it degrades too rapidly to model. In
summary, we used the 34 constituents listed in Table III.E-2 to develop
the risk assessment structure and draft analysis.
c. Phase 3: How Did EPA Choose Additional Constituents for The Risk
Assessment? Before we completed the risk modeling, we added a limited
number of constituents to the 34 we chose initially. We looked at three
groups of constituents. First, since we had chosen the initial group of
constituents in the fall of 1999, we identified five additional
constituents (from the list of 114 constituents with health benchmarks)
that met the criteria for risk assessment (the Agency's Office of
Research and Development identified physical/chemical properties and
SW-846 methods are available). Second, we had 3007 survey responses
reporting which of the 66 constituents (candidates for modeling,
including the 34 we used to develop the risk assessment modeling
structure) occur in non-hazardous waste streams. Finally, we found TRI
data for one additional constituent on the list of 66. Ultimately, we
chose additional constituents based on the 3007 survey reporting.
First we considered the five constituents (from the initial list of
114, but not included in the 66) for which we received later
information identifying physical/chemical properties, and SW-846
methods: these were acetophenone, chlorobenzene, ethyl ether, p-chloro-
meta-cresol, and tetrachloroisophthalonitrile. As with the first group
of 34 constituents, we considered the available data for further
evidence associating the constituents with paint manufacturing
facilities. Acetophenone and chlorobenzene are TRI chemicals but had no
TRI releases reported by SIC 2851 facilities. Ethyl ether, o-chloro-
meta-cresol, and tetrachloroisophthalonitrile are not covered by TRI.
In the BRS, four SIC 2851 facilities reported hazardous wastes that
were listed, at least in part based on chlorobenzene. We found no BRS
reporting of hazardous wastes associated with the other four
constituents.
Then, we also considered the additional information reported in the
3007 survey. The survey listed the 66 constituents that were candidates
for
[[Page 10086]]
risk assessment and asked respondents to identify which constituents
occur in each of their waste streams, both hazardous and non-hazardous.
While response to this question was mandatory, the responses were based
on existing knowledge or waste testing already available to the
respondent. In discussing these results below, ``reporting frequency''
or ``frequency of occurrence'' refers to the number of times each
constituent was reported to occur in a non-hazardous waste stream by a
facility. The numbers reflect the total number of waste streams that
were reported with identified constituents, not the number of
facilities. Some waste streams were reported without any associated
constituents.
In survey data, respondents identified 45 of the 66 constituents
occurring in their non-hazardous waste streams. Frequency of occurrence
ranged from 127 for barium to one for o-xylene and benzyl alcohol.
Twenty-nine of the 34 constituents we chose initially for modeling were
among the 45. We initially modeled the top 22 in terms of reporting
frequency and out of the top 26, we modeled 24. Five of the
constituents we modeled were not identified by respondents as occurring
in non-hazardous waste streams. These results support the
interpretation that our initial approach to choosing constituents was
appropriate.
Finally we considered trichloroethene, which was one of the 66
constituents, but was not initially chosen for risk modeling. We found
there were TRI releases reported for trichloroethene, so we also looked
at survey responses to find how often respondents identified it
occurring in their waste streams. We found that trichloroethene was not
reported in either non-hazardous or hazardous waste streams. We
compared this to responses for several other widely used solvents.
Several were reported in both non-hazardous and hazardous waste streams
and the frequency of reporting was significantly higher in the
hazardous waste streams. For example, toluene was reported in 38 non-
hazardous waste streams and 249 listed hazardous waste streams. Xylene
was reported in 33 non-hazardous waste streams and 246 listed hazardous
waste streams. Ethylbenzene was reported in 6 non-hazardous wastes and
126 listed hazardous waste streams. Comparing ``no reported
occurrence'' of trichloroethene in either non-hazardous or hazardous
waste streams to the non-hazardous/hazardous reporting for other widely
used solvents led us to conclude that trichloroethene is less likely to
be a frequently occurring constituent in non-hazardous waste streams
than other constituents that actually were reported in the survey as
occurring in non-hazardous wastes.\12\ Therefore, we did not model
trichloroethene. It is not a constituent considered as a basis for the
concentration based listing.
---------------------------------------------------------------------------
\12\ Also, generators should know if trichloroethene is in their
wastes because it is a TC constituent (D040, trichloroethylene).
---------------------------------------------------------------------------
We decided to add additional modeling constituents from those
identified in the survey results rather than any of the five
constituents for which we received additional data that would allow us
to conduct risk modeling. We have no TRI data for any of the five
constituents with late-arriving information. BRS data provided some
evidence that chlorobenzene is associated with hazardous wastes from
four paint facilities. In contrast, the survey provides actual
reporting from paint manufacturers on the occurrence of constituents in
their nonhazardous waste streams. We believe that BRS reporting
associated with chlorobenzene at four facilities is less compelling
than reporting frequency in the survey as a basis for adding additional
constituents for risk modeling.
Therefore, we added the following six constituents for risk
modeling based on reported frequency of occurrence in non-hazardous
waste streams: butyl benzyl phthalate with 26 occurrences; acrylamide
with 22 occurrences; benzene with 11 occurrences; and m-,
o-, and p-cresol isomers with 14 occurrences (for m-cresol and o-
cresol). We modeled all three cresol isomers because they are sometimes
difficult to distinguish with available sampling methods and they often
occur together. Also, all three isomers are TC constituents.
In summary we modeled 43 constituents. There are several points to
note concerning the constituents that we modeled:
There are 11 metals on our list of modeling
constituents, and we actually modeled 14 because we modeled
elemental mercury and divalent mercury, chromium III and chromium
VI, and nickel and nickel oxide. Metals exist in a wide variety of
chemical species, and this may be an important factor in assessing
the fate, mobility, and toxicity of metals in our risk analysis. For
the metals noted above, we have sufficient information on mobility
and toxicity to model different species. Metals are present in paint
manufacturing wastes as simple metal salts, or the metal could be
part of a larger organic or inorganic metal compound. For example,
for lead there are a number of compounds used in paints, such as
lead naphthenate, lead molybdate chromate, lead sulfate, lead
chromate, lead oxide, etc. We believe that by modeling these 14
metals, we are in fact representing a broader range of compounds
that are likely to be used in paints. As discussed in the Section
III.E.3 (see discussion on uncertainty in human health risk
results), we recognize that the ionic forms of metals we modeled may
over or under represent the mobility of many of these metal
compounds. However, given that metal speciation may also change as
the constituents move from the waste into the environment, we
believe our modeling efforts are a reasonable approach to assessing
the risks presented by the metals.
Fifteen of the constituents are TC constituents. We
chose to model these because we were concerned that risk-based
levels derived from modeling might be lower than TC concentration
levels. We had experience from the petroleum listing where one TC
constituent, benzene, was present in the wastes below the TC
concentration level and potentially could pose a risk, (see 63 FR
42110, August 6, 1998). In addition, because we intended to conduct
a multi-pathway risk assessment that would take into account direct
and indirect risks from air and ground water as well as from
ingestion of ground water, it was possible that risk-based
concentrations for other exposure pathways might be lower than those
for ingestion of ground water alone, which is the basis for the TC.
Fifteen of the constituents are pigments; ten are
biocides; 17 are solvents; five are binders; and two are driers (the
numbers do not add up to the total number modeled because some
constituents have more than one purpose).
With the addition of the six new modeling constituents,
we modeled 34 constituents with 3007 survey reported waste stream
occurrences ranging from 127 to two. We modeled the top 30 in terms
of reporting frequency in waste streams, with the exception of
acetone (discussed below). We also completed modeling for the five
constituents modeled initially but not reported in the survey,
because there is a possibility that they may occur in the total
universe of paint manufacturing wastes.
We did not model acetone, although it was reported at 11
occurrences, because it was removed from the TRI in 1995. It was
removed from the TRI because ``* * * acetone: (1) Cannot reasonably
be anticipated to cause cancer or neurotoxicity and has not been
shown to be mutagenic and (2) cannot reasonably be anticipated to
cause adverse developmental effects or other chronic effects except
at relatively high dose levels.'' (Federal Register: June 16, 1995
(Volume 60, Number 116), pp. 31643-31646.) On the same day, EPA also
added acetone to a list of compounds excluded from the definition of
a VOC under Title I of the Clean Air Act, based on an Agency
determination that acetone has a negligible contribution to
tropospheric ozone formation.
[[Page 10087]]
Table III.E-2 lists all the constituents that we modeled, the use
category that they fall under and their frequency of occurrence when
they were reported in non-hazardous waste streams.
TABLE III.E-2.--Constituents Modeled for Risk Assessment
------------------------------------------------------------------------
Weighted frequency
of occurrence in
Constituent Purpose non-hazardous waste
streams
------------------------------------------------------------------------
Barium \1\.................. Pigment............. 127.4
Zinc........................ Pigment/Biocide..... 126.8
Vinyl Acetate............... Solvent/binder...... 98.4
Ethylene Glycol............. Solvent............. 90.0
Copper...................... Pigment/Biocide..... 86.7
Chromium III \1\............ Pigment............. 84.6
Chromium VI \1\............. .................... (Identified as
chromium in the
survey)
Cobalt...................... Pigment/drier....... 73.0
Styrene..................... Binder.............. 63.0
Formaldehyde................ Biocide............. 62.8
Lead \1\.................... Pigment/drier....... 58.2
Antimony.................... Pigment............. 45.9
Silver \1\.................. Pigment/biocide..... 45.6
Methanol.................... Solvent/biocide..... 40.0
Toluene..................... Solvent............. 38.8
Methyl Ethyl Ketone \1\..... Solvent............. 36.9
N-Butyl Alcohol............. Solvent............. 35.6
Acrylonitrile............... Binder.............. 35.0
Cadmium \1\................. Pigment............. 34.5
Xylene...................... Solvent............. 33.5
Nickel...................... Pigment............. 28.3
Nickel oxide................ Pigment............. (identified as
nickel in survey)
Phenol...................... Solvent/biocide..... 28.0
Methyl Methacrylate......... Binder.............. 27.2
Butyl Benzyl Phthalate \2\.. Solvent............. 26.6
Acrylamide \2\.............. Binder.............. 22.5
Dibutyl Phthalate........... Solvent............. 22.0
m-Cresol \1,2\.............. Solvent............. 7.45
o-Cresol \1,2\.............. Solvent............. 7.45
p-Cresol 1,2................ Solvent............. ....................
Methyl Isobutyl Ketone...... Solvent............. 11.8
Benzene 1,2................. Solvent............. 11.0
Tin......................... Pigment............. 9.0
Mercury \1\................. Pigment/biocide..... 7.6
Divalent mercury............ Pigment/biocide..... (Identified as
mercury in the
survey)
Ethylbenzene................ Solvent............. 6.1
Selenium \1\................ Pigment............. 5.1
Di(2-ethylhexyl) Phthalate.. Solvent............. 2.2
Chloroform \1\.............. Biocide............. ....................
Methylene chloride.......... Solvent............. ....................
2,4 dimethylphenol.......... Biocide............. ....................
Pentachlorophenol \1\....... Biocide............. ....................
Tetrachloroethylene \1\..... Solvent............. ....................
------------------------------------------------------------------------
\1\ Indicates Toxicity Characteristic (TC) constituents.
\2\ Indicates constituents added to the risk assessment based on
frequency of occurrence reported in the 3007 survey.
5. What Was EPA's Approach to Conducting Human Health Risk Assessment?
Our human health risk analysis for the paint and coating waste
streams estimates the concentrations of individual constituents that
can be present in each waste stream and provide a specified level of
protectiveness to human health and the environment. The human health
risk assessment for the paints and coatings listing determination
evaluates waste management scenarios that may occur nationwide. A
national analysis that captures variability in meteorological and
hydro-geological conditions was selected for this listing because paint
manufacturing is widespread, and facilities that generate the waste
streams of interest are found nationwide.
This risk assessment is intended to limit the risk to individuals
who reside near waste management units used for paint manufacturing
waste disposal by determining the concentrations of particular
constituents that can be managed in paint manufacturing wastes and
remain below a specified individual target risk level.
For this listing, we generated risk-based concentration limits in
waste streams by estimating the concentration of a constituent that can
be managed in the waste streams reported in the 3007 survey and remain
below a target risk level for both cancer risk and noncancer human
health hazards to 90% of the individuals living near waste management
units handling paint manufacturing wastes. Human health impacts are
expressed as estimates of excess lifetime cancer risk for individuals
(called ``receptors'') who may be exposed to carcinogenic contaminants
and as hazard quotients (HQ's) for those contaminants that produce
noncancer health effects. Excess lifetime cancer risk is the
probability of an individual developing
[[Page 10088]]
cancer over a lifetime as a result of exposure to a carcinogen. A
hazard quotient is the ratio of an individual's chronic daily dose of a
noncarcinogen to a reference dose (an estimate of daily exposure that
is likely to be without appreciable risk or deleterious effects over a
lifetime) for exposures to the noncarcinogen. For this listing, the
Agency selected a target risk level for excess lifetime cancer risk for
individuals exposed to carcinogenic (cancer-causing) contaminants of 1
chance in 100,000 (1E-05). For constituents that are non-carcinogens,
the Agency selected the measure of safe intake levels to projected
intake levels, a hazard quotient (HQ), of HQ=1.
The use of these risk levels is consistent with the EPA's hazardous
waste listing policy and the target risk levels used in past hazardous
waste listings (e.g., see 59 FR 24530, December 22, 1994). 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 conjunction with risk in making a listing decision.
EPA's current listing determination procedure uses as an initial
cancer-risk ``level of concern'' a calculated risk level of 1E-05 and/
or environmental risk quotients (EQ's) of 1 at any one point in time.
Waste streams for which risks are calculated to be 1E-04 or higher, or
1 HQ or higher 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 waste streams fall into a category presumptively assumed to
pose sufficient risk to require their listing as hazardous waste.
However, even for these waste streams there can in some cases be
factors which could mitigate the high hazard presumption. Listing
determinations for waste streams with calculated high-end individual
cancer risk levels between 1E-04 and 1E-06 always involve assessment of
additional factors. For today's proposed listing there are several
factors that we considered in setting the risk level of concern, these
included: (1) Certainty in the risk assessment methodology, (2)
coverage by other regulatory programs, (3) damage cases, and (4)
presence of toxicants with unquantifiable risks. We believe a target
cancer risk level of 1E-05 and an HQ of 1 is appropriate for this
listing, but we welcome comments and supporting data if there is a
compelling reason for an alternative target.
To calculate listing levels for constituents of concern, we needed
to determine what concentrations at the point of exposure would be
associated with levels in the waste for each waste stream and waste
management unit. We used three types of analyses to determine the risks
associated with the management of paint manufacturing wastes: (1) A
probabilistic analysis for all waste management scenarios; (2) a
deterministic analysis for all waste management scenarios, and (3) a
bounding analysis for on-site management of waste waters in treatment
tanks. The results of the bounding analysis demonstrated that given the
concentrations of constituents that we expect in paint manufacturing
waste the risk generated from paint manufacturing wastes managed in on-
site tanks is not significant. The following sections describe the risk
assessment.
(1) Probabilistic Analysis (Monte Carlo Method). A probabilistic
analysis calculates distributions of results (in this case protective
waste concentrations for each constituent) by allowing some of the
parameters used in an analysis to have more than one value. The model
is run numerous times (for this analysis we ran the model 10,000 times)
each time with different values selected from the distributions of
input parameters. A parameter is any one of a number of inputs or
variables (such as waste volume or distance between the waste
management unit and the receptor) required for the fate and transport
and exposure models and equations that EPA uses to assess risk. In the
probabilistic analysis, we vary sensitive parameters for which
distributions of data are available. Parameters varied for this
analysis include waste volumes, waste management unit size, parameters
related to the location of the waste management unit such as climate
and hydro-geologic data, location of the receptor, and exposure factors
(e.g., drinking water ingestion rates). In some cases, in order to
maintain the inherent correlation between parameters, we treat multiple
parameters as a single parameter for the purpose of conducting the
analysis. We do this to prevent inadvertently combining parameters in
our analyses in ways that are unrealistic. For example, we treat
environmental setting (location) parameters such as climate, depth to
groundwater, and aquifer type as a single set of parameters. We believe
that, for example, allowing the climate from one location to be paired
with the depth to groundwater from another location could result in a
scenario that would not occur in nature.
The probabilistic analysis is conducted using a Monte Carlo
methodology. Monte Carlo analysis provides a means of quantifying
variability in risk assessments by using distributions that describe
the full range of values that the various input parameters may have.
Some of the parameters in the probabilistic analysis are set as
constant values because (1) there are insufficient data to develop a
probability distribution function ; (2) EPA made assumptions to
simplify the analysis in cases where such simplifications would improve
the efficiency of the analysis without significantly affecting the
results; and (3) the analysis has not been shown to be sensitive to the
value of the parameter, that is, even if the parameter varies, the
resulting risk estimate does not vary significantly. The result of the
probabilistic risk assessment is a distribution of risk-based
concentration limits or ``listing levels.'' The EPA used the results of
the probabilistic risk assessment to determine the regulatory listing
levels.
(2) Deterministic Analysis. The deterministic method uses single
values for input parameters in the models to produce a point estimate
of risk or hazard. We used the deterministic analysis to corroborate
the results of the probabilistic analysis. For the deterministic
analysis, we conduct both a ``central tendency'' and a ``high end''
deterministic risk assessment. These two analyses attempt to quantify
the cancer risk or non-cancer hazard for the ``average'' receptor in
the population (the central tendency risk) and the risk or hazard for
individuals in small, but definable ``high end'' segments of the
population (the high end risk). For central tendency deterministic risk
analyses, we set all parameters at their central tendency values. For
the paint and coatings risk assessment, the central tendency values
generally are either mean (average) or 50th percentile (median) values.
We use high end deterministic risk analyses to predict the risks and
hazards for those individuals exposed at the upper range of the
distribution of exposures. EPA's Guidance For Risk Characterization
(EPA 1995) advises that ``conceptually, high end exposure means
exposure above about the 90th percentile of the population
distribution, but not higher than the individual in the population who
has the highest exposure,'' and recommends that ``* * * the assessor
should approach estimating high end by identifying the most sensitive
variables and using high end values for a subset
[[Page 10089]]
of these variables, leaving others at their central values.'' As such,
for the paint and coatings risk assessment, high end deterministic risk
analyses, EPA established a set of the parameters most likely to
influence the results of the assessment and set two of these parameters
at a time to their high end values (generally 90th percentile values),
and set all other parameters at their central tendency. The high-end
deterministic analysis results are based on the two most ``sensitive
parameters.'' These are the two parameters that when set at their high-
end values, generated the highest estimate of risk or hazard. These two
most ``sensitive parameters'' vary according to the constituent and
pathway evaluated. Appendix C of the risk assessment technical
background document shows the two most sensitive parameters for each
constituent and pathway. The EPA did not perform a sensitivity analysis
on all parameters in this risk assessment. Rather, the parameters we
selected to vary in the deterministic analysis were a smaller list
based on sensitivity analyses performed on the same models for other
listing determinations that determined the most sensitive parameters in
our models. For the aboveground pathways, the parameters considered
most likely to influence the results were the waste management unit
surface area, the distance to the receptor, the meteorological station
location, the sorption coefficients for the waste management unit and
surficial soil, the receptor's exposure duration, and the volume of
paint waste in the waste management unit. For the groundwater pathways,
the parameters considered most likely to influence the results
included; the distance to receptor well, depth to groundwater, the
sorption coefficients, the receptor's exposure duration, and the volume
of paint waste in the waste management unit. We did not use the
deterministic analysis to develop today's proposed listing levels. The
deterministic analysis is discussed in more detail in the Technical
Background Document
(3) Bounding Analysis. This type of analysis is very conservative
but presents a quick and simple way to ``screen out'' potential
scenarios of concern. A bounding analysis was used for the on-site tank
scenario because, based on previous listing determinations, we did not
think volatilization from the small volumes managed on-site was likely
to generate a risk of concern. Similar to the deterministic and
probabilistic analyses, the results of this risk assessment are the
concentration of each constituent that can be managed in a tank and
remain protective of human health. To conduct this analysis, the most
sensitive or risk-driving parameters in the risk assessment tank model
were varied between their high-end and central tendency values. The
tank characteristics (i.e., capacity, surface area, and diameter) used
in the analysis were based on the tank reported by the facility with
the highest waste volume managed in a tank. The tank modeled was a 9000
gallon, aerated waste water treatment tank. For the analysis we assumed
there was no biodegradation in the tank. Similar to the deterministic
assessment, two high-end parameters were varied at a time to determine
the greatest ``high-end'' risk combination. The greatest reported waste
volume was always used as one of the high-end parameters in the two
parameter combination. The three other high-end parameters were varied
between their high-end and central tendency values. These three
parameters were; the distance from the waste management unit to the
receptor, the duration that the receptor was exposed to the
contaminant, and the meteorological location of the waste management
unit. Based on the results of this analysis, we determined that the
risk of waste water management in on-site tanks is insignificant for
all constituents for one of three different reasons: (1) The estimated
constituent concentration was greater than 1 million parts per million
and therefore was not physically achievable, (2) the estimated
constituent concentration was above the constituent's RCRA hazardous
waste toxicity characteristic and the waste would already be classified
as hazardous, or (3) we determined, based on knowledge of paint
formulations, that non-hazardous paint manufacturing waste waters would
never contain concentrations of the constituent at the level that may
produce a risk (see Section for further discussion).
a. What Waste Management Scenarios Were Evaluated? We evaluated
four waste management units that represent plausible management
scenarios that are likely destinations for paint and coating production
waste streams. The modeled units include landfills, surface
impoundments, on-site tanks, and off-site tanks. Section III.D
describes in detail why these waste management units were selected for
evaluation in the risk assessment. The waste management scenarios for
each of these units were created using information reported by industry
on the management of their non-hazardous paint manufacturing waste
streams. In addition, we used information on the national distributions
of waste management unit characteristics (e.g., size and waste
capacity) collected with surveys conducted for other rulemakings to
establish the characteristics of the off-site waste management units.
(i) Type of Waste Management Units and Their Characteristics. We
evaluated commercial industrial non-hazardous landfills, surface
impoundments, and off-site tanks for the probabilistic and
deterministic risk assessment. On-site tanks were also evaluated in a
bounding analysis. With the exception of the on-site tanks, each type
of waste management unit has a distribution that characterizes the
units with respect to capacity and dimension (e.g., area and depth).
These dimensions and operating characteristics are important
determinants of the extent to which a contaminant may be released from
the unit. Each type of waste management unit is assumed to have
different operational lifetimes (between 20-50 years) and different
lengths of time during which constituents are assumed to be released
from the unit (between 30 and 200 years).
For landfills and surface impoundments we evaluated the scenario of
disposal in an unlined waste management unit and assessed the impact of
the release of leachate from the landfill and surface impoundment to
the groundwater. In addition, we assumed that the landfill did not have
daily cover and the surface impoundment was open to the air. The
primary source of data used to establish the characteristics of
landfills and surface impoundments for both the probabilistic and
deterministic analysis is our 1985 Screening Survey of Industrial
Subtitle D Establishments.\13\ There are over 2,850 landfills reported
in this survey. Since paint manufacturing facilities reported that
their wastes were sent to off-site landfills, the characteristics the
sixty-eight landfills reported in this survey to accept wastes in all
or in-part from off-site sources were selected for characterizing the
landfills included in this assessment.
---------------------------------------------------------------------------
\13\ Schroeder, K.R. Clickner, and E. Miller, 1987. Screening
Survey of Industrial Subtitle D Establishments. Draft Final Report.
Prepared for the Office of Solid Waste, U.S. Environmental
Protection Agency. Westat, Inc. Rockville, MD.
---------------------------------------------------------------------------
There were 1,930 surface impoundments reported in the 1985
Industrial D Screening Survey. Twenty-seven of these surface
impoundments were not included in the distribution used for this risk
assessment because the data were not complete in the survey or the
facility indicated that the
[[Page 10090]]
surface impoundments were only used as backup storage units. A
stratified random sample of 200 of the remaining 1,903 surface
impoundments was used in the analysis. Data on the surface impoundment
total capacity and total 1985 waste quantity were used in the analysis.
Surface impoundments were assumed to be operated with varying degrees
of aeration. Aeration characteristics were not a parameter reported in
the Industrial D survey and in the absence of this data, the
distribution of aeration characteristics from the tanks database
(described below) was randomly applied to surface impoundments.
For the evaluation of off-site management of waste waters in
treatment tanks, a tank database was developed for this analysis that
compiled flow rates, treatment methods, and tank volumes. The primary
source for these data was EPA's 1986 National Survey of Hazardous Waste
Treatment, Storage, Disposal, and Recycling Facilities (TSDR)
Database.\14\ Although this database collected information on hazardous
waste tanks, this database was used since it is the most comprehensive
collection available of information on tank characteristics. Since
similar treatment technologies are used for hazardous and non-hazardous
waste we believe that the characteristics of non-hazardous tanks is not
significantly different from hazardous tanks. This database is a result
of a comprehensive survey of 2,626 TSDR facilities, on 1986 waste
management practices and quantities. A subset of the data contained
information on 8,510 tanks that received wastes from off-site. Since it
was not computationally feasible to model all 8,510 of the tanks for
this analysis, a sample from the tanks in this survey was used to
develop the characteristics of off-site tanks. There were several
criteria used in selecting a sample from the tanks in the 1986 survey.
Some of the criteria used were: (1) Only those tanks reporting flow
rates (demonstrating they were used for waste management) were included
in the analysis, (2) only treatment tanks were considered in the
analysis and tanks that were closed or covered were not included in the
distribution, (3) no reported tanks with a volume the size of a drum or
smaller were included since these are likely to be short-term units or
containers. From all the tanks that met the above mentioned criteria, a
sample of 200 tanks was drawn from the data that comprised the tank
distribution. The sampling was conducted to preserve the range and
distribution of tanks in the underlying database. To reflect emission
characteristics associated with differences within the treatment tank
category related to aeration intensity, three different tank categories
were identified and modeled: high aerated treatment tanks, low aerated
treatment tanks, and nonaerated (quiescent) treatment tanks. Examples
of quiescent treatment tanks are clarifiers and filters (such as sand
or mixed-media filters). In the absence of aeration, quiescent
treatment tanks are still subject to small amounts of agitation during
filling and emptying operations if the tank has above-surface intakes.
Sorting the tanks in the database into these three categories was done
using the data reported in the TSDR category.
---------------------------------------------------------------------------
\14\ U.S. EPA. 1987. 1986 National Survey of Hazardous Waste
Treatment, Storage, Disposal, and Recycling Facilities Database.
---------------------------------------------------------------------------
(ii) Location of Waste Management Units. Determining the location
of waste management units is important for the selection of
environmental setting data (e.g., meteorological and hydrological data)
for constituent fate and transport modeling. Since we do not know the
location of all specific paint production waste disposal, we assumed
that waste disposal locations are correlated with the location of the
paint production facilities. We also assumed that nonhazardous waste
from paint manufacturing facilities is disposed within reasonable
transport distances of the facility. Therefore, we created a
distribution of locations of paint manufacturing waste treatment and
disposal facilities across the United States. The locations of waste
management in the distribution are weighted according to the total
dollar value of product shipments reported for a State. We assumed that
the larger the total dollar value of shipments, the greater the volume
of paint production in the State and we weighted the probabilistic
analysis accordingly. In other words, the meteorological locations in
States with the larger reported dollar value of paint shipments in the
probabilistic analysis had more of the 10,000 iterations. The source of
information on the dollar value of product shipments is the 1997
Economic Census of Paint and Coating Manufacturing (U.S. Department of
Commerce, 1999).\15\ The Census reported the dollar value of shipments
made by paint manufacturing facilities by State. In all, 36 states
reported paint production volumes on a dollar value basis. The Census,
however, included only States for which facility data can be reported
without disclosing confidential business information. Data cannot be
reported if the population of paint manufacturing facilities is so
small that confidentiality cannot be maintained if data were reported
on a State level. Since the States not included in the 1997 Census may
only have a few paint manufacturing facilities, not including these
States does not impact this analysis. Locations for modeling were
selected first for States according to the volume of paint manufactured
and then by the general location of paint manufacturing facilities
within the State. The EPA's 1997 Toxic Release Inventory was used to
determine the possible location of the paint manufacturing facilities
within a State. In many cases the majority of the paint manufacturing
facilities were located in several clusters throughout a State.
Therefore, in some cases several different meteorological stations and
hydrological regimes within a single State were modeled. Forty-nine
meteorological stations in 39 states were used in the risk assessment.
---------------------------------------------------------------------------
\15\ U.S. Department of Commerce. 1999. Paint and Coating
Manufacturing: 1997 Economic Census; Manufacturing Industry Series.
EC97M-3255A. U.S. Census Bureau, Washington, D.C. August.
---------------------------------------------------------------------------
(iii) Waste Volumes. In Part III, Section D, we explained how we
identified waste volumes reported in the 3007 survey data that
represent the distribution of volumes of non-hazardous waste being sent
to non-hazardous landfills, surface impoundments, and tanks across the
nation. We compiled distributions of waste solids sent to landfills and
waste liquids sent to tanks and surface impoundments. Each waste volume
has a corresponding weighting factor that represents the number of
facilities in the total sampling population that sent a particular
waste volume to a particular type of waste management unit. The risk
assessment modeling requires the use of volumes going to a waste
management unit, therefore the waste quantities here are presented as
volumes (in gallons) as opposed to mass (in tons), the waste descriptor
that has been used in previous sections of this preamble. For the
probabilistic risk assessment the weights were used to determine the
frequency a waste volume was evaluated in the 10,000 iterations
comprising the Monte Carlo analysis. In general, the waste volumes
reported were relatively small when compared to the total waste
capacity of the waste management units. For the probabilistic analysis,
the volumes of emission control dust going to a landfill range from 40
gallons to 78,650 gallons, the volumes of all the solids going to a
landfill range from 5 gallons to 426,739
[[Page 10091]]
gallons, and the range of aqueous wastes that can be managed in either
a surface impoundment or off-site tank is from 151 gallons to 104,225
gallons. For the deterministic analysis, the 50th and 90th percentile
waste volumes from each of the volume distributions was used. These
volumes are shown in Table III.E-3 below.
Table III.E-3.--Waste Volumes Used for the Risk Assessment
----------------------------------------------------------------------------------------------------------------
Emission Combined
Percentile control dust solids Liquid wastes
(gallons/yr) (gallons/yr) (gallons/yr)
----------------------------------------------------------------------------------------------------------------
Minimum......................................................... 40 5 151
50th............................................................ 644 375 12,000
90th............................................................ 58,340 43,270 26,752
Maximum......................................................... 78,650 426,739 104,225
----------------------------------------------------------------------------------------------------------------
b. What Exposure Scenarios Did EPA Evaluate? Prior to conducting
the risk assessment, we had to establish that there is a plausible
scenario under which a receptor might be exposed to contaminants
managed in paint manufacturing wastes. Establishing this scenario
required that we determine: how the waste is managed, how contaminants
can be released from the waste management unit, how contaminants can be
transported in the environment to a point of contact with a receptor;
and how a receptor can be exposed to a contaminant. For the reasons
discussed in Part II, Section D, we chose to evaluate the risk
attributable to management of paint production wastes in uncovered
biological treatment tanks, uncovered and unlined surface impoundments,
and uncovered and unlined non-hazardous industrial landfills.
(i) Release Scenarios From Waste Management Units. We determined
that releases from all of the waste management units (tanks, landfills,
and surface impoundments) can occur through release of vapor emissions
to the air. In addition, particulate emissions to the air from solids
disposed in landfills is feasible. For the landfill and surface
impoundment waste management scenarios, it was also determined that
releases could occur through leaching of waste into the subsurface. We
assumed that tanks were sufficiently impermeable that they were highly
unlikely to release volumes of waste sufficient to pose an unacceptable
groundwater risk. Therefore it was not necessary to develop risk-based
concentrations for the groundwater pathway. The mechanisms and pathways
we evaluated are as follows:
1. Vapor emissions can remain dispersed in the air, or can be
deposited through wet and dry deposition. Specifically, we modeled
the concentration of vapor phase contaminants in air, the diffusion
of vapor phase contaminants into plants, the diffusion of vapor
phase contaminants into surface water, wet deposition of vapors onto
soils and surface water, dry deposition of vapors onto soils, and
dry and wet vapor deposition onto plants.
2. Particulate emissions can remain dispersed in the air or be
deposited through wet deposition (in precipitation) or dry
deposition (particle settling). We assume that particulates may be
deposited onto soil and surface water through both wet and dry
deposition, and onto plants through dry deposition.
3. Leachate can migrate through the unsaturated zone to the
saturated zone, where contaminants are transported in groundwater to
drinking water wells.
4. Constituents deposited onto soils from vapor and particulate
emissions can erode into nearby surface water bodies.
(ii) Routes of Exposure. Human receptors may come into contact with
the chemicals of concern present in environmental media through a
variety of routes. In general, exposure pathways are either direct,
such as inhalation of ambient air, or indirect, such as consumption of
contaminated food products. For this risk assessment, human receptors
may come into contact indirectly with vapors that diffuse into
vegetation, particulates that are deposited onto vegetation, or
contaminants that are taken up by vegetation from the soil and ingested
in fruits and vegetables, as well as exposure to contaminated beef and
dairy products derived from cattle which have ingested contaminated
forage, silage, grain, and surface soil. Receptors that ingest fish may
also indirectly come into contact with contaminants in air-borne vapors
and particulates (through vapor diffusion into surface water, vapor
deposition onto surface water, and particulate deposition onto surface
water) and runoff and eroded soil that has entered the surface water
body.
(iii) Receptors Evaluated. Most paint facilities transport wastes
generated during paint production to waste management units located
off-site. For the off-site waste management units identified in the
RCRA 3007 survey (e.g., landfills) it is not uncommon to have
residential, recreational, or agricultural land uses surrounding the
management unit. As such, we determined that the following receptors
reasonably represent the types of individuals that may be located near
the waste management units and could be exposed to contaminants in
paint production wastes:
An adult resident,
The child of a resident,
A farmer,
The child of a farmer,
A recreational fisher.
Some of these receptors might be exposed through several pathways
and some might only be exposed through one pathway. Receptors are
evaluated for exposures with respect to chemicals present in ambient
air (both vapors and particles), soils, groundwater, fruits and
vegetables, beef and dairy products, and fish. The magnitude of the
exposure received by a receptor is dependant on the chemical and
environmental setting modeled. The following sections describe our
primary assumptions regarding the characteristics and activities of
each of the receptor types, and the routes by which each receptor is
exposed.
Adult Resident and Child of the Resident. We assume that an adult
and child can reside near the waste management unit. The residential
receptors inhale vapors and particulate matter that are dispersed in
the ambient air. We assume that household water is supplied to the
residential receptors by a private groundwater well that is located
near their home. The adult resident and the child of the resident,
drink water that comes from the well. We assume that the adult resident
inhales vapors that are emitted from the water used for showering. The
residential receptors do not ingest foods that are grown in the
vicinity of their home, however, they do incidentally ingest surface
soil from their yard. Groundwater exposures were only considered for
the residential scenario. It was assumed that contaminated groundwater
was not used for crop irrigation or stock water for cattle. In
addition, groundwater recharge and
[[Page 10092]]
subsequent contamination of fish was not considered. In general, the
exposure to contaminants through the air pathway and contaminants in
the groundwater occurs at very different time scales due to the long
transport times associated with most chemicals in the groundwater
medium. For example, transport of contamination to a receptor in
ambient air can happen within a matter of hours while transport of
contaminants to a residential well in groundwater can take hundreds,
even thousands of years. As such, we did not add together the exposures
from both the air pathway and groundwater pathway. There were a few
organic constituents where the contaminant did travel to the receptor
well in less than 50 years, however, we did not add together the
exposures from these two pathways since the receptor locations for the
groundwater and air pathways are different, therefore adding the
exposures is not appropriate. We did add together the exposures from
different routes for each receptor. For example, for carcinogens, we
considered the additive exposure for an adult resident from ingestion
of groundwater and inhalation of vapors while showering when it was
appropriate.
Adult Farmer and Child of the Farmer. We assume that a farmer
raises fruits, exposed vegetables, root vegetables, beef cattle, and
dairy cattle in an agricultural field located near the waste management
unit. Approximately 42 percent of the exposed vegetables, 17 percent of
the root vegetables, 33 percent of the exposed fruits, 3 percent of the
protected fruits, 49 percent of the beef, and 25 percent of the dairy
products eaten by the farmer are grown/raised on the farmer's
agricultural field. We assume that the farmer and the child of the
farmer incidentally ingests soil from his/her yard.
Recreational Fisher. We assume that the residential receptor may be
a recreational angler. Approximately 33 percent of the fish eaten by
the fisher are from a stream located near the waste management unit.
The fisher's other characteristics and activities are the same as those
of the adult resident.
We establish the locations of all the receptors relative to waste
management units based on information obtained from previous national
surveys. These surveys are discussed below. Exposure to groundwater
occurs through the use of water from drinking water wells, and exposure
via non-groundwater pathways occurs through releases to the air.
Therefore, ``distance to receptor'' for the groundwater pathways is the
distance to the drinking water well that the receptor is using (the
``receptor well''). ``Distance to the receptor'' for non-groundwater
pathways is the distance to the residence where the receptor is
inhaling air or contacting the soil or the distance to the field where
the receptor is growing crops or raising livestock. Consequently, we
use different databases to establish ``distance to receptor,''
depending on whether we are evaluating a groundwater or a non-
groundwater pathway.
For analysis of the air pathways risks in the deterministic
analysis we assume that the receptors live either 75 meters (m) (high
end) or 300 m (central tendency) from the waste management unit. The
distance of 250 feet (ft) (approximately 75 m) is based on the actual
measured distance to the nearest resident for the worst-case facility
evaluated in the risk assessment conducted to support the 1990
``Hazardous Waste Treatment, Storage, and Disposal Facilities-Organic
Air Emissions Standards for Process Vents and Equipment Leaks Final
Rule'' (55 FR 25454), and was used as distance to the nearest resident
for that rulemaking. In the same risk assessment, we identified the
receptor distance of 1000 ft (approximately 300 m) as the median
distance in a random sample of distances to the nearest residence. For
the deterministic analysis, we used the average air concentration and
deposition values around the circumference at both 75 m and 300 m. For
the probabilistic analysis, we identified the distance of 300 m as the
median or central tendency distance from the WMU to the receptor. We
then used the 75 m distance as a 10th percentile closest location
(high-end) and created a normal distribution of receptor distances to
sample from. The lowest and highest receptor distances (0 and 100
percentile) of the distribution were constrained to be between 50 and
550 m. The distance from the WMU boundary to the resident location was
randomly selected from this distribution. In addition, the receptors in
the probabilistic analysis are located in 16 directions around the
entire circumference (360 degrees) of the waste management unit.
For evaluating the groundwater pathway in the deterministic
analysis, we assume that a receptor well is located 102 m (high end) or
430 m (central tendency) from the waste management unit, and that the
receptor well is located on the centerline of the plume (high end) or
halfway between the centerline and the edge of the contaminant plume
(central tendency). The 102 m distance is the 10th percentile value in
the distribution of distances derived from our 1988 survey of Solid
Waste (Municipal) Landfill Facilities. The 430 m value is the 50th
percentile value in that same distribution. For the probabilistic
analysis, the distance from the waste management unit to the receptor
well is based on the complete distribution of distance to the receptor
well reported by the survey respondents, and ranges from 0.6 m to 1610
m. For the Monte Carlo analysis we assume that the receptor well is
located anywhere within the contaminant plume.
The Technical Background Document for the risk assessment provides
a complete discussion of the values of additional parameters that
define the characteristics of each receptor, such as the amounts of
contaminated food and water they ingest, their inhalation rates, and
how long they live near the waste management unit (i.e., their exposure
duration).
c. How did EPA Quantify Each Receptors Exposure to Contaminants?
Exposure is the condition that occurs when a contaminant comes into
contact with the outer boundary of the body, such as the mouth and
nostrils. Once we establish the concentrations of contaminants at the
points of exposure, we can estimate the magnitude of each receptor's
contaminant dose. Dose is the amount of contaminant that crosses the
outer boundary of the body and is available for adsorption at internal
exchange boundaries (lungs, gut, skin). For example, for exposure to a
carcinogen through ingestion of contaminated drinking water, dose is a
function of the concentration of the contaminant in the drinking water
(exposure point concentration), as well as certain exposure factors,
such as how much drinking water the receptor consumes each day (the
intake rate), the number of years the receptor is exposed to
contaminated drinking water (the exposure duration), how often the
receptor is exposed to contaminated drinking water (the exposure
frequency), the body weight of the receptor, and the period of time
over which the dose is averaged. Our primary source of exposure factors
is the ``Exposure Factors Handbook'' published by EPA in August 1997.
For probabilistic analyses, we used the distributions of exposure
factor values provided in the Exposure Factors Handbook. The one
situation where we do not develop an expression of dose is the case
where we use the Reference Concentration (RfCs) to estimate noncancer
hazard for the inhalation exposure route. In this situation, we
calculate noncancer hazard from concentration of the contaminant in air
[[Page 10093]]
and the RfC, without considering exposure factors other than those
inherent in the RfC (e.g., inhalation rate, body weight).
Children are an important sub-population to consider in a risk
assessment because they are likely to be more highly exposed to
contaminants in the environment than adults. Compared to adults,
children eat more food and drink more fluids per unit of body weight.
This higher rate coupled with a lower body weight can result in higher
average daily dose than adults experience. To evaluate childhood
exposure for this analysis, a child of a resident and a child of a
farmer whose exposure begins between the ages of 1 and 6 was evaluated.
For the probabilistic assessment, a start age was randomly chosen
between the ages of 1 and 6. The child was then aged for the number of
years defined by the exposure duration. As children mature, however,
their physical characteristics and behavior patterns change. To capture
these changes in the analysis, the life of a child was divided into
several cohorts: Cohort 1 (ages 1-5), Cohort 2 (ages 6 to 11), cohort 3
(ages 12 to 19), and cohort 4 (ages 20 to 70). Each cohort has a
discrete value (for a deterministic assessment) and a distribution (for
a Monte Carlo analysis) of exposure parameters that are required to
calculate exposure to an individual. The exposure parameter
distributions for each cohort reflect the physical characteristics and
behavior patterns for that age range.
d. How Did EPA Predict The Release and Transport of Constituents
From a Waste Management Unit to Receptor Locations? We conduct
contaminant fate and transport modeling and indirect exposure modeling
to determine what the concentrations of contaminants will be in the
media that the receptor comes into contact with. These concentrations
are called ``exposure point concentrations'' (that is, they are the
contaminant concentrations at the point where the receptor is exposed
to the contaminants.) There are a number of computer-based models and
sets of equations that we use to predict exposure point concentrations.
In the following sections we briefly discuss these models and equations
and their application in the risk analyses.
(i) Landfill Partitioning Model. The landfill model is designed to
simulate the gradual filling of an active landfill and the long-term
releases from the active and closed landfill cells. The design assumes
that the landfill is composed of a series of vertical cells of equal
volume that are filled sequentially. We assumed that each cell requires
one year to be filled. The formulation of the landfill model is based
on the assumptions that the contaminant mass in the landfill cells
might be linearly partitioned into the aqueous, vapor, and solid
phases. The partitioning coefficients are based on those reported in
literature, and are listed in the risk assessment's Technical
Background Document. The model simulates the active lifetime of the
landfill (30 years) and continues simulating releases until less than
one percent of the initial mass is left or for a total of 200 years,
whichever occurs first. We assume that the landfill has minimal
controls with no liner and no daily cover. However, we assumed that
there is no runoff and erosion from the unit. The cover at closure is a
soil cover that still permits volatilization. We used the highest 9-
year average leachate concentration predicted by the partitioning model
as input into EPA's Composite Model for Leachate Migration with
Transformation Products (discussed in Section III.E(b)(vii)).
Based on the design assumptions above, we simulated the annual
release of chemical mass by leaching to the unsaturated zone underneath
the landfill, volatilization to the air pathway, and particle emissions
to the air pathway from wind erosion and truck movement during the
active lifetime. It is assumed that the contaminant mass emitted as a
particulate from the landfill is sorbed to particles in the waste. The
model estimates the emission rate of contaminant mass adsorbed to
particle sizes less than 30 micrometers (µm). The amount of
contaminant mass emitted is assumed to be distributed between four
particle size categories, 30 to 15 µm (40%), 15 to 10
µm (10%), 10 to 2.5 µm (30%), and less than 2.5
µm (20%).\16\ While the emission control dust may be comprised
primarily of the smaller size particles, we assumed that the waste
material becomes mixed with other wastes and soils before being
released as a particulate, therefore the particle size distribution
used for estimating the particulate releases represent the range of
particles sizes for all the wastes that may be in a landfill. We did
not attempt to assess possible risks from short-term releases of
unmixed dust particles that might occur during initial placement of
wastes into the landfill cells. However, we do not believe such
releases are likely to be significant for several reasons: (1) Dusts
sent to landfills are typically contained, and are thus unlikely to
cause large scale releases when placed in a landfill, (2) dust volumes
are relatively small, especially in comparison to the size of
commercial offsite landfills, and would likely be covered with other
wastes at the landfill in a short time period, and (3) significant
dusting would be minimized by both typical operating practices at
landfills (e.g., dust suppressant activities), as well as regulations
controlling air releases (e.g., see: Federal regulations for daily
cover for municipal landfills at 40 CFR 258.21; widespread State
requirements for cover at non-municipal Subtitle D,\17\ and
requirements under State Implementation Plans approved pursuant to
section 110 of the CAA).
---------------------------------------------------------------------------
\16\ ``Compilation of Air Pollutant Emission Factors,'' AP-42,
Section 13.2.5: Industrial Wind Erosion, U.S. Environmental
Protection Agency, Office of Air and Radiation and Office of Air
Quality Planning and Standards, September 1995.
\17\ U.S. Environmental Protection Agency, Office of Solid
Waste, State Requirements for Industrial Non-Hazardous Waste
Management Facilities, October 1995.
---------------------------------------------------------------------------
In addition, we simulated losses of mass through both anaerobic and
aerobic biodegradation and hydrolysis within the landfill. We did not
simulate the transport of constituents from the landfill as non-aqueous
phase liquids (NAPL's). However, we do not believe that the waste
streams evaluated for the landfill scenario will form NAPL's (see
Section IV E). In addition, due to the variability of waste stream
characteristics across the paint industry, it is impossible to know the
exact composition of the waste matrices (e.g., the constituents present
and the exact constituent concentrations), therefore, modeling did not
take into account the effect of managing multiple solvents in the same
waste stream. The management of multiple solvents in a waste may create
a ``co-solvency effect'' where the solubility of a solvent may be
increased due to the presence of other solvents.
The partitioning model incorporates other assumptions intended to
improve the efficiency of the model. These assumptions are described in
detail in the risk assessment technical background document. The
assumptions include the lack of lateral transport between cells,
simulation of only a single cell and then aggregation of results based
on the time each cell is filled, and the assumption that waste is added
at a constant concentration at a constant rate.
(ii) Surface Impoundment Partitioning Model. The surface
impoundment model simulates the disposal of liquid wastes in an unlined
surface impoundment and the releases of chemicals during the lifetime
of the
[[Page 10094]]
unit. The highest 9-year average leachate concentration is then used as
input into EPA's Composite Model for Leachate Migration with
Transformation Products (see section vii) which estimates the movement
of the plume through the saturated and unsaturated zone over a 10,000
year time period. Runoff and erosion from the unit do not occur because
we assume the impoundment is a sink in the watershed. We assume that
there is no liner other than native soils and that the unit is not
covered. The model assumes that the waste in the impoundment consists
of two phases: Aqueous liquid and sediment. The model does not simulate
any additional phases, such as non-aqueous phase liquids (NAPL's).
However, we do not believe that NAPL formation is likely in the wastes
evaluated for this listing (see Section IV E). The model simulates the
changes at the bottom of the impoundment over time as settled solids
fill pore space in native soils and act to reduce chemical transport to
underlying soils and groundwater. In addition, a fraction of each
surface impoundment is aerated, which enhances biodegradation and
increases volatilization of some chemicals. The surface impoundment is
assumed to operate 50 years and then undergoes clean closure (that is,
all the waste is removed from the unit). Based on the design
assumptions, the surface impoundment module simulates annual release of
leachate to the unsaturated zone and volatile emissions to the air. The
model does not account for redeposition of volatiles into the unit from
precipitation. The model accounts for several biological, chemical, and
physical processes including hydrolysis, volatilization, sorption as
well as settlement, resuspension, growth and decay of solids, activated
biodegradation in the liquid phase (that is, a higher rate based on the
amount of biomass present) and hydrolysis and anaerobic biodegradation
in the sediments.
(iii) Tank Emissions Model. The tank model simulates time-varying
releases of constituents to the atmosphere. The tank unit only has
volatile emissions (no particulate emissions) and the tank is assumed
to have an impervious bottom so that there is no contaminant leaching.
The treatment tank is divided into two primary compartments: a
``liquid'' compartment and a ``sediment'' compartment. Mass balances
are performed on these primary compartments at time intervals small
enough that the hydraulic retention time in the liquid compartment is
not significantly impacted by the solids settling and accumulation. In
the liquid compartment, there is flow both in and out of the WMU.
Solids generation occurs in the liquid compartment due to biological
growth; solids destruction occurs in the sediment compartment due to
sludge digestion. Using a well-mixed assumption, the suspended solids
concentration within the WMU is assumed to be constant throughout the
tank. However, some stratification of sediment is expected across the
length and depth of the WMU so that the effective total suspended
solids (TSS) concentration within the tank is assumed to be a function
of the WMU's TSS removal efficiency rather than equal to the effluent
TSS concentration. The liquid (dissolved) phase contaminant
concentration within the tank, however, is assumed to be equal to the
effluent dissolved phase concentration (i.e., liquid is well mixed).
The tank model does not consider separate non-aqueous phase liquid
(NAPL) in the tank that might exist if a constituent is above its
solubility limit. We do not believe that constituents managed in paint
production waste will have high enough concentrations in waste waters
to form an oily film layer on top of the tank. As such, we believe the
modeling performed with this tank model is appropriate.
(iv) Air Dispersion and Deposition Model. The atmospheric modeling
performed for this risk assessment provides annual average estimates of
air concentrations of chemicals released from the waste management
units and annual deposition rate estimates for vapors and particles at
various receptor points in the areas of interest. The chemicals that
are emitted are either in the form of volatilized gases or fugitive
dust. The simulated air concentrations are used to estimate biological
uptake from plants and human exposures due to direct inhalation. The
predicted deposition rates are used to determine chemical loadings to
watershed soils, farm crop areas, and surface waters. The atmospheric
concentration and deposition of chemicals were determined through a
steady-state Gaussian plume modeling approach using the Industrial
Source Complex-Short Term (ISCST3) model. Each of the waste management
unit types were modeled as an area source with ISCST3. ISCST3 provides
hourly meteorological data and estimates of contaminant concentration,
dry deposition (particles only) and wet deposition (particles and
gases) for user-specified averaging periods. Dry deposition of vapors
was also calculated, but outside the dispersion model. Annual averaging
periods were used for this analysis. These long averaging times are
consistent with the use of chronic benchmarks in this analysis. The
dispersion model uses information on meteorology (e.g., wind speed and
direction, temperature) to estimate the movement of constituents
through the atmosphere. Modeling was conducted using five years of
hourly data obtained from 49 representative meteorological stations
throughout the country. Meteorological stations were selected based on
the location of paint manufacturing facilities.
Currently, algorithms specifically designed to model the dry
deposition of gases have not been verified for the specific compounds
in question (primarily volatile organics). In place of algorithms, we
used a transfer coefficient to model the dry deposition of gases. A
concern with this approach is that the deposition is calculated outside
the model. As a result, the mass that we estimate deposits on the
ground from the plume is not subtracted from the air concentrations
estimated by ISCST3. This results in a slight non-conservation of the
mass in the system.
Due to the complexity of the analysis, it was not computationally
feasible to run ISCST3 on an hourly basis for the lifetime of all the
unit configurations. To reduce the computational burden, we made
several simplifications to the air modeling. The dispersion model is
sensitive to the surface area of the waste management unit. In order to
make the dispersion modeling computationally feasible, we divided the
different waste management unit configurations into area-based bins
that represented the distribution of surface areas for each of the
waste management unit types. For each waste management unit type, the
median area for each bin was input into ISCST3 and modeled at each of
the 49 meteorological stations. For tanks, each area-height combination
was modeled for each of the 49 meteorological locations. For any
specific unit, the median air concentration and deposition values for
the bin that most closely represented the specific unit's surface area
was used. Another simplification used in the dispersion modeling is
that a scavenging coefficient for all gases was used based on
approximating the gases as very small particles. This approach
eliminates the need for running ISCST3 for each specific chemical, thus
reducing the overall runtime. This simplification might lead to
underprediction of wet deposition for some gases and over-prediction
for others depending on the Henry's Law coefficient of the gas.
[[Page 10095]]
(v) Overland Transport Model. Addition of constituents to soils,
called constituent loading, can result from atmospheric deposition and
overland movement of constituents. The primary loading mechanisms of
constituents onto soils is by wet and dry deposition predicted with the
dispersion model. This constituent deposition was predicted based on
the average air concentration and deposition flux for both the buffer
area and the agricultural field. We assumed that there was no erosion
and runoff from the WMU to the surrounding soils since we assumed that
the landfill and surface impoundment were below grade. However, erosion
and runoff (overland transport) were evaluated to predict the movement
of deposited contaminants onto agricultural fields and into nearby
water bodies. Five constituent losses in the surface soils were
considered: (1) Leaching of the chemical due to precipitation; (2)
erosion of the chemical laterally along with the soil due to water; (3)
runoff of the dissolved chemical with the lateral flow of water; (4)
biodegradation of the chemical in situ; (5) volatilization losses of
the chemical. The Universal Soil Loss Equation (USLE) was used to
estimate soil erosion losses. The USLE is an erosion model originally
designed to estimate long-term average soil erosion losses from an
agricultural field having uniform slope, soil type, vegetative cover,
and erosion-control practices. We used a modified form of the USLE to
estimate the mass of soil lost per year per unit from the soils around
the waste management unit and deposited in the runoff directly onto the
receptor site (agricultural field and residential lot) and into a
nearby stream. We assume the receptor location is between the waste
management unit and the surface water body. The area around the waste
management unit is considered for the purposes of our analysis to be an
independent, discrete drainage subbasin that is at steady-state. We
estimate the soil erosion load from the subbasin to the surface water
body using a distance-based sediment delivery ratio, and consider that
the sediment not reaching the surface water body is deposited evenly
over the area of the subbasin. Using equations, we estimate contaminant
contributions to the surface water body and the receptor soil. Soils
were characterized within a 20 mile radius around each meteorological
station using data obtained from the 1994 U.S. Department of
Agriculture's State Soil Geographic Data Base and other relevant
sources that are described in Appendix I of the risk assessment's
Technical Background Document.
(vi) Surface Water Model. We assume that fish are exposed to waste
constituents in surface water. Specifically our modeling assumes that
fish are exposed to contaminants in the water column, contaminants
sorbed to suspended solids in the water column, and contaminants
associated with the bed sediment in the surface water body. The beef
cattle and dairy cows are exposed to both dissolved and suspended
constituent concentrations in the surface water. The model accounts for
four ways in which contaminants may enter the surface water body: (1)
Contaminants may be sorbed to eroded soils that enter the surface water
body, (2) contaminants may be dissolved in runoff that enters the
surface water body, (3) contaminants may be bound to airborne particles
that are deposited on the surface water body, and (4) vapor phase
contaminants in air may be deposited on the surface water body in
precipitation (that is, wet deposition of vapor phase contaminants).
The model also accounts for processes that remove contaminants from the
surface water body. These include: (1) Volatilization of contaminants
that are dissolved in the surface water body and (2) burial of
contaminants in the sediment at the bottom of the surface water body.
The model assumes that the impact to the water body is uniform, which
is more realistic for smaller water bodies than for larger ones. The
model estimates the concentrations of contaminants in the water column
and bed sediment. We used the water column or bed sediment
concentrations and bioconcentration factors or bioaccumulation factors.
The water body used in this analysis is a stream located down gradient
of the WMU. Depending on the receptor scenario that is evaluated, the
stream is either adjacent to the buffer area (the area that separates
the WMU from the human receptor locations) or is located adjacent to
the agricultural field on the side farthest from the WMU. For modeling
purposes, the stream is shaped as a rectangle 5.5 m wide and as long as
the width of the agricultural fields. The assumption is that the stream
is a typical third-order fishable stream. The stream segment modeled in
this assessment is assumed to be homogeneously mixed with a depth of
0.21 meters (including water column and benthic sediments) and has a
flow of 0.5 m/s. This stream is the smallest water body that would
routinely support recreational fishing of consumable fish. Because we
modeled a small stream with a constant flow rate, the stream scenario
is a conservative (environmentally protective) estimate of the
constituent concentration in a surface water body that results from
soil runoff and air deposition.
(vii) Groundwater Model. We used EPA's Composite Model for Leachate
Migration with Transformation Products (EPACMTP) to model the
subsurface and transport of contaminants that leach from the waste
management units (landfills and surface impoundments) and migrate to a
residential drinking water well. We assume that the soil and aquifer
are uniform porous media and that flow and transport is described by
Darcy's law and the advection-dispersion equation, respectively.
EPACMTP accounts for the following processes affecting contaminant fate
and transport: Advection, hydrodynamic dispersion, equilibrium sorption
by the soil and aquifer solids (both in the unsaturated and saturated
zones), and contaminant hydrolysis. EPACMTP does not account for
preferential pathways such as fractures, macropores, or facilitated
transport (i.e., any chemical process that has the potential to speed
the transport of a pollutant beyond what is expected), which may
increase the migration of constituents.
The groundwater pathway consists of two components: Flow and
transport in the vadose zone (that is, the unsaturated zone directly
below the unit), and flow and transport in the saturated zone. The
primary transport mechanisms in the subsurface are downward movement
along with infiltrating water flow in the unsaturated zone and movement
along with ambient groundwater flow in the saturated zone. The
advective movement in the unsaturated zone is one-dimensional, while
the saturated zone module accounts for three-dimensional flow and
transport. The model also considers mixing due to hydrodynamic
dispersion in both the unsaturated and saturated zones. In the
unsaturated zone, flow is gravity-driven and prevails in the vertically
downward direction. Therefore, the flow is modeled in the unsaturated
zone as one-dimensional in the vertical direction. It is also assumed
that transverse dispersion (both mechanical dispersion and molecular
diffusion) is negligible in the unsaturated zone. This assumption is
based on the fact that lateral migration due to transverse dispersion
is negligible compared with the horizontal dimensions of the WMUs. In
addition, this assumption is environmentally protective because it
allows the leading front of the constituent plume to arrive at the
water table with greater peak concentration.
[[Page 10096]]
In the saturated zone, the movement of constituents is primarily
driven by ambient groundwater flow, which in turn is controlled by a
regional hydraulic gradient and hydraulic conductivity in the aquifer
formation. The model does take into account the effects of infiltration
from the waste source as well as regional recharge into the aquifer.
The effect of infiltration from the waste source is to increase the
groundwater flow in the horizontal transverse and vertical directions
underneath and in the immediate vicinity of the waste source as may
result from groundwater mounding. This three-dimensional flow pattern
will enhance the horizontal and vertical spreading of the plume. The
effect of regional recharge outside of the waste source is to cause a
downward dip in the movement of the plume as it moves in the
downgradient groundwater flow direction.
In addition to advective movement along with groundwater flow, the
model simulates mixing of contaminants with groundwater due to
hydrodynamic dispersion, which acts in the longitudinal, (i.e., along
the groundwater flow direction), as well as in horizontal and vertical
transverse directions. The rate of movement of contaminants may be
strongly affected by sorption reactions in both the unsaturated and
saturated zone. The effect of sorption is expressed in a retardation
factor, which is directly related to the magnitude of the constituent-
specific KD value (K.C. in the case of
organdies). Constituents with a zero or low KD (or
K.C.) value will have a retardation factor of 1, or close to
it, which indicates that they will move at the same velocity as the
groundwater, or close to it. Constituents with high KD
values, such as certain semi volatile organic constituents and many
metals, will have high retardation factors and may move many times
slower than groundwater. EPA has sometimes used the MINTEQA2
equilibrium speciation model to estimate Kd's for a variety of metals
rather than relying solely on field measurements. However, recently a
number of technical issues have been raised concerning the model and
its application.\18\ EPA is in the process of evaluating the model to
address those issues. Therefore, we have decided not to use MINTEQA2
for today's proposed rule. Once the evaluation is completed and the
issues are satisfactorily resolved, EPA may again choose to use the
model in an appropriate form in future rulemakings. For today's
proposed rule, we used values for metal Kd's that have been derived
from field studies and have been published in the scientific
literature. An empirical distribution was used to characterize the
variability of Kd for chemical contaminants for which sufficient
published data were available. However, for chemical contaminants
having relatively few published values, a log uniform distribution was
used in which a three log unit (three orders of magnitude) expansion
was made around the geometric mean of the data. This was done to better
account for the variability most often seen in measurements of Kd and
to capture the uncertainty that comes from having limited data. Our use
of empirically derived partition coefficients assumes that sorption is
linear with respect to concentration (i.e., the Kd isotherm is linear).
However, sorption is not unlimited and will tend to level off as
groundwater concentrations increase beyond the linear range (i.e., Kd
isotherm becomes non-linear). This condition is most likely to occur in
the unsaturated zone where dilution is limited, if leachate
concentrations are sufficiently high.
---------------------------------------------------------------------------
\18\ Norris, C.H. and C.E. Hubbard, 1999. Use of MINTEQA2 and
EPACMTP to estimate groundwater pathway risks from the land disposal
of metal-bearing wastes. Prepared for Environmental Defense Fund,
Friends of the Earth, Hoosier Environmental Council, and Mineral
Policy Center.
---------------------------------------------------------------------------
(viii) Indirect Exposure Methodology. We use a series of ``indirect
exposure equations'' to quantify the concentrations of contaminants
that pass indirectly from contaminated environmental media to the
receptor. For example, contaminants that are transported in air may be
deposited on plants or onto the soil where they may accumulate in
forage, grain, silage, or soil that is consumed by beef cattle and
dairy cattle. Individuals may then ingest contaminated beef and dairy
products. Similarly, contaminants may be transported in groundwater to
domestic groundwater wells where the groundwater is extracted and used
for showering. The water vapor generated in the shower may be inhaled
by the receptor. The indirect exposure equations allow us to calculate
exposure point concentrations for these pathways and routes of
exposure. The indirect exposure equations we use to conduct this risk
assessment are presented in the Technical Background Document for the
risk assessment.
e. What Is The Human Health Toxicity of COC's Identified by EPA? To
characterize the risk from human exposures to the constituents of
concern, toxicity information on each COC is integrated with the
results of exposure assessment. Chronic human health benchmarks were
used in this risk assessment to evaluate potential noncancer and cancer
risks. We use reference doses (RfDs) and reference concentrations
(RfCs) to evaluate noncancer health impacts from oral and inhalation
exposures, respectively. Oral cancer slope factors (CSF's), inhalation
unit risk factors, and inhalation CSFs are used to evaluate risk for
carcinogens. The benchmarks are chemical-specific and do not vary
between receptors (i.e., residents, farmers, recreational fishers) or
age groups. We use several sources to obtain human health benchmarks.
Health benchmarks for this risk assessment were obtained primarily from
the most recent Integrated Risk Information System (IRIS) and the most
recent Health Effects Assessment Summary Tables (HEAST). IRIS and HEAST
are maintained by EPA, and the values from IRIS and HEAST were used in
this analysis whenever available \19\. If IRIS or HEAST chronic
benchmarks were not available, we sought benchmarks from alternative
sources. Provisional EPA benchmarks, Agency for Toxic Substances and
Disease Registry minimal risk levels, California Environmental
Protection Agency (CalEPA) chronic inhalation reference exposure
levels, and CalEPA cancer potency factors were used when values were
not available from IRIS and HEAST. The benchmark for lead is unique.
Instead of using the benchmarks described above, the Office of Solid
Waste and Emergency Response (OSWER) soil screening level of 400 ppm
was used as the benchmark for the air pathways in this analysis. The
SSL number developed by OSWER accounts for all identified sources of
lead exposure (including background). The soil screening level was
derived by predicting the concentration of lead that can be in soils in
a child's play area such that a typical child would have an estimated
risk of no more then 5% of exceeding a 10 ug/dL blood lead level. In
addition, the EPA's drinking water action level for lead of 0.015 mg/L
was used for the groundwater pathway. We also used a drinking water
action level for the groundwater pathway analysis for copper since an
ingestion benchmark was not available.
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\19\ We are aware that health benchmarks for several
constituents of concern or potential constituents of concern are
currently being reevaluated in IRIS. Reviewers should note that if
the IRIS health benchmarks change, the Agency would likely use the
most current benchmarks as the basis for setting concentration
levels.
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Appendix Q of the Risk Assessment Technical Background Document
contains the toxicological profiles used in our analysis. The studies
used as the basis for each of these benchmarks have
[[Page 10097]]
been reviewed and summaries of these studies, along with reference to
the complete studies, are presented in Appendix Q of the Risk
Assessment Background Document.
f. What Are The Results From The Risk Assessment? We developed
concentration limits based on the following waste management unit/waste
stream combinations:
Emission control dust managed in a landfill.
Combined volumes of emission control dust, sludges from
waste water treatment, and solid off-specification production wastes
(called ``combined solids'' in the results table) going to a landfill.
All waste waters managed in a surface impoundment.
All waste waters managed in tanks.
For the landfill and surface impoundment scenarios we have risk-
based concentration limits for the air and groundwater pathways. We
assumed that tanks were sufficiently impermeable that they were highly
unlikely to release sufficient volumes of waste to pose an unacceptable
groundwater risk that therefore it was not necessary to develop risk-
based concentrations for the groundwater pathway. Other than mercury,
the air pathway is not relevant for metals managed in waste waters
because of their low volatility.
The small waste volumes generated by the paint and coatings
manufacturing industry resulted in most of the potential constituents
of concern not creating an unacceptable risk. For example, the central
tendency waste volume for emission control dust is 2.44 m\3\ annually
(approximately 644 gallons). When compared to the central tendency
capacity of a landfill cell (the annual capacity of a landfill over a
30 year life), the landfill cell is more than 1000 times larger. This
results in a thousand fold dilution effect for the leachate when waste
is placed in a landfill. Another way to put the waste volumes into
perspective is to consider that the central tendency emission control
dust waste volume reported by the paint and coating facilities
comprises only 0.07% of the capacity of a median sized landfill.
Most of the constituents screened out of the air pathway because
the predicted concentration limits were either greater than 1 million
parts per million (physically impossible) or greater than what the EPA
expects to be managed in paint manufacturing wastes. Specifically, out
of the 43 constituents evaluated in both the landfill and surface
impoundment scenarios, only 5 had air pathway concentration limits
below 1 million parts per million (ppm). In the tank scenario, only 3
constituents had protective waste concentrations that were below 1
million ppm.
Table III.E-2 shows the calculated risk-based concentration levels
for all the possible constituents of concern in each of the waste
stream scenarios evaluated\20\. The results are the total concentration
in either mg/kg for solids (landfills) or mg/L for liquids (surface
impoundments and off-site tanks) that can be managed in the units and
remain protective of human health. The concentration levels in Table
III.E-4 represent the probabilistic results at the 90th percentile risk
level based on individuals living closest to the waste management unit.
In other words, these concentration numbers meet a target cancer risk
level of 10-5 or hazard quotient of 1 for 90% of the receptor scenarios
we evaluated. As discussed previously, we are attempting to calculate
estimates of exposure in the upper end of the distribution (i.e., above
90th percent), while avoiding estimates that are beyond the true
distribution. EPA guidance for risk characterizations states that ``the
`high end' of the risk distribution (generally the area of concern for
risk managers) is conceptually above the 90th percentile of the actual
(either measured or estimated) distribution. This conceptual range is
not meant to precisely define the limits of this descriptor, but should
be used by the assessor as a target range for characterizing `high-end
risk'.\21\'' Therefore, a high-end estimate that falls within the range
(at or above the 90th percentile but still realistically on the
distribution) is a reasonable input to a decision.\22\
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\20\ Reviewers should note that inputs used in he modeling to
support today's proposal may change, and minor modifications to the
model itself may be made as a result of ongoing internal quality
assurance/quality control reviews, internal peer review and public
comments. As a consequence, the proposed constituent levels may
change as well. Reviewers should bear in mind that levels that
increase or decrease sufficiently could result in adding or deleting
constituents from the listing, based on whether the risk-based
levels are likely to occur in paint production wastes.
\21\ ``Guidance on Risk Characterization for Risk Managers and
Risk Assessors'', by then Deputy Administrator F. Henry Habicht,
1992.
\22\ The distributions are distributions of concentrations that
when found in paint production wastes will generate risks of 10-5 or
an HQ of 1 for individuals living closest to paint manufacturing
waste facilities. The ``90th percentile'' then is the concentration
in paint manufacturing waste at which 90% of the individuals living
closest to paint manufacturing waste management facilities will be
protected to these levels.
---------------------------------------------------------------------------
We are soliciting comment on our use of the 90th percentile risk
level, rather than other high-end risk levels, such as the 95th
percentile, to set the regulatory concentration. If we used the 95th
percentile results, the calculated listing levels would be about a
factor of 3 lower. In addition, if we used the 95th percentile results,
we would consider adding an additional constituent in the listing for
liquid wastes (methanol; see Section IV.A for a list of the
constituents we are proposing for listing). Details of the levels
calculated using the 95th percentile are given in the Technical
Background Document for the risk assessment.
In this listing we are proposing to set the levels at the 90th
percentile, because we believe that the 90th percentile levels are
protective. We have limited information on constituent levels in wastes
because, for the reasons stated earlier, we did not sample waste
streams. Thus, we do not know with any certainty that a large fraction
of paint production wastes will be close to the levels derived from
either the 90th or 95th percentile. Based on the limited data from our
survey of the industry, we expect that many of the paint production
wastes generated will not approach these concentrations, but will
likely be well below the proposed listing levels. Thus, we think that
the paint production waste that would remain nonhazardous at the
proposed levels would pose risks below that indicated by the benchmark
risk-level at either the 90th or 95th percentile.
We are proposing to establish a concentration-based listing that
sets a threshold level below which wastes would not be considered
hazardous. This is different from the usual listing determinations we
have made in the past. In a traditional listing, all wastes meeting the
listing description are regulated as hazardous, with no provision to
test for levels of hazardous constituents present. In a traditional
listing, if we determined not to list a waste, then all of the waste
would go unregulated and the risk remains unaffected. A concentration-
based listing, however, would regulate the higher risk wastes and
potentially leave lower risk wastes unregulated. This means that by
setting the listing levels at the 90th percentile, we are ensuring that
the residual risk for the unregulated wastes would likely be below the
risk associated with the risk based on an assessment of all wastes.
Therefore, we believe that using the 90th percentile levels to set the
listing levels is appropriate for this concentration-based listing.
Note that we also recently proposed to use the 90th percentile risk
levels to set listing levels in the listing for two wastes from the
dyes and pigments industries (64 FR 40192, July
[[Page 10098]]
23, 1999); this was also a concentration-based listing that established
a threshold, below which wastes would not be listed. For traditional
listing decisions, we considered a range of high-end risk results,
including a range of probabilistic results at or above the 90th
percentile, e.g., see the proposed listings for wastes from the
production of chlorinated aliphatics (64 FR 46476, August 25, 1999) and
inorganic chemicals (65 FR 55684, September 14, 2000).
Table III.E-4.--Calculated Risk-Based Concentration Levels for Possible Constituents of Concern in Paint and Coatings Waste \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Emission control dust (mg/kg) Combined solids (mg/kg) Waste waters in surface
--------------------------------------------------------------------- impoundments (mg/L) Waste waters in
Constituents ---------------------------------- off-site tanks
Air pathway Groundwater Air pathway Groundwater Groundwater (mg/L)
pathway pathway Air pathway pathway
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acrylamide...................... E 3.1E+02 E 4.7E+02 2.3E+05 1.2E+01 E
Acrylonitrile................... 1.3E+05 4.3E+01 1.7E+05 6.0E+01 1.9E+04 9.3E+00 6.9E+04
Antimony........................ E 2.3E+03 E 3.2E+03 M 3.9E+02 M
Barium.......................... E E E E M E M
Benzene......................... 6.3E+05 3.1E+04 7.9E+05 4.7E+04 1.0E+05 5.6E+02 1.9E+05
Butylbenzylphthalate............ E L E L E E E
Cadmium......................... E 1.3E+05 E 2.8E+05 M 3.9E+04 M
Chloroform...................... E 6.0E+05 E E E 1.5E+02 E
Chromium III.................... E E E E M E M
Chromium VI..................... E 6.8E+04 E 6.6E+04 M 8.8E+03 M
Cobalt.......................... E E E E M E M
Copper.......................... E E E E M E M
Cresol, m....................... E E E E E 2.2E+04 E
Cresol, o-...................... E E E E E 2.5E+04 E
Cresol, p-...................... E E E E E 2.6E+03 E
Di(2-ethylhexylphthalate)....... E L E L E E E
Dibutylphthalate................ E L E L E E E
Dichloromethane................. E 2.4E+05 E 3.3E+05 E 4.5E+03 E
Dimethylphenol 2,4-............. E E E E E 1.7E+04 E
Divalent mercury................ 6.0E+05 E 8.7E+05 E 2.5E+04 6.4E+05 E
Ethylbenzene.................... E L E L E 1.1E+04 E
Ethylene glycol................. E E E E E 7.9E+05 E
Formaldehyde.................... E 9.3E+05 E E E 8.2E+04 E
Lead............................ E E E E M E M
Mercury......................... 1.6E+05 E 2.1E+05 E 5.9E+03 E 1.0E+04
Methanol........................ E E E E E 2.0E+05 E
Methyl ethyl ketone............. E 1.5E+05 E 2.2E+05 E 8.2E+03 E
Methyl isobutyl ketone.......... E 7.3E+04 E 1.2E+05 E 3.4E+02 E
Methyl methacrylate............. E 2.8E+04 E 4.1E+04 E 2.1E+03 E
N-butyl alcohol................. E 9.7E+05 E E E 4.1E+04 E
Nickel.......................... E E E E M E M
Nickel oxide.................... E B E B M B M
Pentachlorophenol............... E 9.6E+04 E 1.6E+05 E 1.0E+04 E
Phenol.......................... E E E E E 2.7E+05 E
Selenium........................ E 2.5E+04 E 3.4E+04 M 6.1E+03 M
Silver.......................... E E E E M E M
Styrene......................... E E E E E 4.6E+03 E
Tetrachloroethylene............. E 1.4E+04 E 2.1E+04 E 4.8E+02 E
Tin............................. E E E E M E M
Toluene......................... E E E E E 1.2E+03 E
Vinyl acetate................... E G E G E G E
Xylene (mixed isomers).......... E L E L E 3.9E+03 E
Zinc............................ E E E E M E M
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Levels represent the 90th percentile protective waste concentration derived from the probabilistic analysis.
L = screened out of the groundwater due to no leachate.
E = risk-based waste concentration exceeds 1 million (1E+06) parts per million.
B = screened out of the pathway due to a lack of a human health toxicity benchmark.
M = not included in the risk analysis for that pathway since the constituent is a non-volatile metal.
g. What Is The Uncertainty in Human Health Risk Results?
Uncertainty is a description of the imperfection in knowledge of the
true value of a particular parameter. This risk assessment has inherent
limitations that lead to uncertainty in our risk estimates because of
the complexity associated with simulating the behavior of a chemical
moving through the environment from disposal in a management unit, to
exposure points in various environmental media, and subsequent impacts
on receptors. As explained below, limitations also result from the
amount, type, and quality of the data used in our assessment, the set
of exposure pathways evaluated, and the types of waste management units
considered. Because of the number of facilities that manufacture paint
and
[[Page 10099]]
coatings, it was not feasible for us to directly measure data such as
facility/site characteristics (for example, unit area and volume; depth
to groundwater; aquifer thickness; hydraulic conductivity; location of
wells; type of ecological receptors; behavioral characteristics of
receptors) at each representative site to estimate risk.
This section discusses the major areas of uncertainty in risk
assessments as classified by the EPA: scenario uncertainty, model
uncertainty, and parameter uncertainty.
(a) Scenario uncertainty results from the assumptions we make
regarding how receptors become exposed to contaminants. This
uncertainty occurs because of the difficulty and general impracticality
of making actual studies of all activities involved in the management
of a waste and the human activities that occur around the waste
management unit.
This risk assessment does not consider the additive
risk from exposure to multiple constituents. Chemical mixtures can
display both synergistic and antagonist behavior with regard to
risk. In general, however, the overall risks of a mixture are very
likely to be greater than that of exposure to a single chemical.
Therefore not adding exposures across the chemicals is an area of
uncertainty that leads to an underestimate of total risk. We did not
calculate the additive effects from multiple-chemical exposure since
there was not information on the concentrations or co-management of
particular constituents. In addition, for a concentration based
listing it is not reasonable to set standards for a constituent that
are developed based on the assumed presence of other constituents
that have the same health affect. Whether or not a particular
chemical mixture poses an additive risk or hazard depends on the
targets (tissue, organ, or organ system), the concentrations of all
the constituents in the mixture, and the mechanisms of action of the
individual chemicals. Without information on the co-management of
constituents, it was not feasible to consider additive risks.
In certain cases, EPA performs a risk assessment on
wastes that contain contaminants that also are present in the
environment as a result of both natural processes and anthropogenic
activities. Under these circumstances, receptors potentially receive
a ``background'' exposure that may be greater than the exposure
resulting from release of contaminants from the waste. For national
analysis like this assessment, the inclusion of background
concentrations as part of the analysis is not feasible due to (a)
the variability of background concentrations nationwide and (b) the
lack of data on national background concentrations for each
constituent.
(b) Parameter uncertainty occurs when (1) there is a lack of data
about the parameters used in the equations, (2) the data that are
available are not representative of the particular instance being
modeled, or (3) parameter values cannot be measured precisely and/or
accurately because of limitations in measurement technology. Random, or
sample errors, are a common source of parameter uncertainty that is
especially critical for small sample sizes. More difficult to recognize
are nonrandom or systematic errors that result from bias in sampling,
experimental design, or choice of assumptions.
The age of several of the databases used in this
analysis to characterize the waste management units or the location
of the receptors leads to uncertainty in the analysis. These
databases contain information collected by the EPA in several
surveys during the mid- to late 1980's. While these databases
represent the best available information the Agency had at the time
of this analysis, uncertainty exists in the analysis on changes in
waste management practices or residential locations that may have
occurred during the past decade. The uncertainty associated with
these data may lead to an over or under estimate of risk.
The sorption coefficient, Kd, which is used
in the source partition model, the groundwater model, and in
modeling constituent concentration in surficial soils, is an
important parameter for modeling the fate and transport of metals in
the environment. In previous analyses, Kd values were
calculated using MINTEQ but, because of comments on the validity of
some of the data upon which MINTEQ calculations are based, EPA
decided, for this analysis, that Kd values would be
derived from literature values. A comprehensive review of the
literature was undertaken to compile Kd data for an
earlier rulemaking (Inorganic Chemicals Listing Determination, 65 FR
55684, September 14, 2000.) Despite this substantial earlier effort,
considerable uncertainty remains in the literature-based values of
Kd used in this analysis because data concerning
Kd values for particular constituents reported in the
literature were limited. In addition, reported values often were not
accompanied by qualifying information. Conditions that affect
Kd values (e.g., constituent concentration, metal species
evaluated, pH, experimental technique) are often not reported in the
literature making interpretation of results difficult. For these
reasons, substantial uncertainty concerning the values of
Kd remain.
Very little data were available on the physical and
chemical characteristics of paint manufacturing waste. To address
this, assumptions on the waste characteristics are based on general
knowledge of paint and other similar industrial wastes. In this
analysis, except for constituent concentration, which was
calculated, EPA assumes that the paint manufacturing waste is mixed
with other generic industrial wastes. Therefore, general waste
characteristics, including default assumptions for the waste
parameters (e.g., fraction of organic carbon, pH), were used.
We used waste volume data in this risk assessment
provided by the facilities as part of our RCRA 3007 survey. Since
the survey was not a census, there is some uncertainty associated
with the waste volume distribution. This uncertainty may lead to an
over or under estimate of risk.
We typically use regional databases to obtain the
parameter values necessary to model contaminant fate and transport.
Because the data that we used are not specific to the facilities at
which the actual wastes are managed, the data represent our
estimates of the generic site conditions. For an analysis where
waste management locations are so variable, we believe this type of
approach is reasonable and is the best method to address the fate
and transport of constituents. Nevertheless, the use of these
databases in lieu of site-specific data may result in either
overestimates or underestimates of risk.
Sources of uncertainty in toxicological benchmarks
include one or more of the following: extrapolation from laboratory
animal data to humans, variability of response within the human
population, extrapolation of responses at high experimental doses
under controlled conditions to low doses under highly variable
environmental conditions, and adequacy of the database (number of
studies available, toxic endpoints evaluated, exposure routes
evaluated, sample sizes, length of study, etc.). Toxicological
benchmarks are designed to be conservative (that is potentially
overestimate risk) because of the uncertainties and challenges
associated with condensing toxicity data into a single quantitative
expression. Uncertainty factors are applied to address limitations
of the available toxicological data and are necessary to ensure the
RfD or RfC is protective of individuals in the general population.
The use of uncertainty factors is based on long-standing scientific
practice. Uncertainty factors, when combined commonly range from 10
to 1000 depending on the nature and quality of the underlying data.
The RfD/RfC methodology is expected to have an uncertainty spanning
perhaps an order of magnitude.
We recognize that significant uncertainties and
unknowns exist regarding the estimation of lifetime cancer risks in
children. We estimated the risk of developing cancer from the
estimated lifetime average daily dose and the slope of the dose-
response curve. A cancer slope factor is derived from either human
or animal data and is taken as the upper bound on the slope of the
dose-response curve in the low-dose region, generally assumed to be
linear, expressed as a lifetime excess cancer risk per unit
exposure. However, individuals exposed to carcinogens in the first
few years of life may be at increased risk of developing cancer.
The non-cancer toxicological effects in children is
also an area of uncertainty. Non-cancer reference doses and
reference concentrations for children are based on comparing
childhood exposure, for which we have age-specific data, with adult
toxicity measures, where adequate age-specific dose-response data is
lacking. This mismatch results in a large amount of uncertainty in
the estimation of hazard quotients for children. This would
sometimes result in an overestimation of children's risk and
sometimes in an underestimation. This issue
[[Page 10100]]
is still under investigation in the scientific community and no
consensus has been reached.
(c) Model uncertainty is associated with all models used in all
phases of a risk assessment, because models and their mathematical
expressions are simplifications of reality that are used to approximate
real-world conditions and processes, and their relationships. Computer
models are simplifications of reality, requiring exclusion of some
variables that influence predictions but cannot be included in models
due either to increased complexity or to a lack of data on a particular
parameter. Models do not include all parameters or equations necessary
to express reality because of the inherent complexity of the natural
environment, and the lack of sufficient data to describe the natural
environment. Because this is a probabilistic assessment that predicts
what may occur with the management of certain paint manufacturing
wastes under assumed scenarios, it is not possible to compare the
results of our models to any specific situation that may exist. The
risk assessor needs to consider the importance of excluded variables on
a case-by-case basis because a given variable may be important in some
instances and not in others. A similar problem can occur when a model
that is applicable under average conditions is used for conditions that
differ from the average. In addition, in some instances choosing the
correct model form is often difficult when conflicting theories seem to
explain a phenomenon equally well. In other instances, the Agency does
not have established model forms from which to choose to address
certain phenomena, such as facilitated transport. We selected models
used in this risk assessment based on science, policy, and professional
judgement. Most of the models selected have been verified and some have
been validated. In addition, most of these models have been peer
reviewed. These models were selected because they provide the
information needed for this analysis and because we generally consider
them to be state-of-the-science. Even though the models used in the
risk analyses are used widely and have been accepted for numerous
applications, they each retain significant sources of uncertainty.
Evaluated as a whole, the sources of model uncertainty in our analysis
could result in either an overestimation or underestimation of risk.
Specific areas of modeling uncertainty in this analysis are:
There were constituents identified as materials used in
paint manufacturing that were not modeled in this risk assessment
due to a lack of information on how they behave when introduced to
the environment. Our fate and transport modeling is limited to those
constituents for which we have (1) the physical/chemical parameters
necessary to run our models and (2) adequate information on toxicity
to understand potential health impacts from exposure. In selecting
constituents of concern, we found multiple constituents that were
complex inorganic compounds containing more than one metal of
concern and organometallic compounds (compounds containing both a
metal and organic constituents) that can be used in manufacturing
paint. For example, compounds such as lead chromate molybdate and
lead naphthenate may be used as ingredients in paint. An adequate
set of both the physical/chemical parameters and toxicity
information for modeling fate and transport and predicting risk to
human health are lacking for these metal complexes. The technical
background document for the risk assessment contains the information
we found on a set of organometallics. Due to this absence of data,
we simulate the risk presented by these multiple compounds by
modeling the ionic form of the metal. For example, the model
predictions for lead are used to represent the complex lead
inorganic metal compounds and lead organometallic compounds that may
be used in paints. Since so little is known about these complex
metal compounds and what their fate may be in the environment, our
modeling may over or under-estimate the actual risks. In addition,
for metals transformations may take place as the pH of the waste or
media can change the state of the metal, sometimes to a less toxic
form and sometimes to a more toxic form. The risk assessment did not
model transformation products or changes in metal species.
Exposure modeling relies heavily on default assumptions
concerning population activity patterns, mobility, dietary habits,
body weights, and other factors. There are some uncertainties
associated with some of the data used for these parameters. Although
it is possible to study various populations to determine various
exposure parameters (e.g., age-specific soil ingestion rates or
intake rates for food) or to assess past exposures (epidemiological
studies) or current exposures, risk assessment is about prediction.
Therefore, long-term exposure monitoring in this context is
infeasible. The Exposure Factors Handbook provides the current
state-of-the-science concerning exposure modeling and assumptions
and is used in this risk assessment. To the extent that actual
exposure factors vary from the assumptions in this risk assessment,
risks could be underestimated or overestimated.
In modeling the fate and transport of chemicals in
groundwater, we did not assess complex hydrogeology such as karst or
highly fractured aquifers. Some fraction of the groundwater settings
in this analysis have fractured flow. In general, fractured flow in
groundwater can channel the contaminant plume, thus allowing it to
move faster and more concentrated than in nonfractured flow
environment. As a result, our modeling may under or over estimate
the concentrations in the groundwater.
Finally, there is uncertainty in predicting the
movement of contaminants over long periods of time. We assess the
risk to receptors for the groundwater pathway over a time period of
10,000 years. There are significant uncertainties regarding how
exposure, scientific, and environmental assumptions will change over
time, and the modeling methodology does not change these assumptions
over this 10,000 year period.
We request comments on each of these areas of uncertainty,
including their potential impact on our conclusions and whether data
are available to improve our analysis.
6. What Was EPA's Approach To Conducting the Ecological Risk
Assessment?
Waste management activities cannot only impact the health of
individuals living near a WMU, but can also have adverse effects on
other organisms and natural systems. For example, wildlife can come
into contact with constituents released from WMUs by swimming or living
in contaminated waters or by drinking or catching prey such as fish
from contaminated waters. For this risk assessment, the EPA conducted
an ecological risk screening analysis for all the waste management
units evaluated for the human health risk assessment. The purpose of
this analysis was to identify whether there is potential for adverse
ecological effects from the management of paint production waste in
landfills, surface impoundments, and off-site treatment tanks. We
performed this ecological risk assessment with a two tiered approach.
For the first tier, we assumed that each of the constituents evaluated
had a concentration in the waste of 750,000 parts per million. This
concentration was a starting number for the analysis and does not have
any significance to the way in which paint wastes are currently
managed. This waste concentration was selected as a concentration level
to perform a screening analysis with since it is greater than what the
EPA expects would be managed in paint manufacturing wastes. All
constituents except for mercury and lead did not pose an unacceptable
risk to ecological receptors at this concentration. For these two
constituents, we performed a second level of analysis. For mercury and
lead, we predicted what concentrations could be managed in each waste
management unit to ensure that all ecological receptors experience a
hazard quotient of 1 or less when compared to the 90th percentile
environmental media concentrations. These concentrations were 270,000
ppm and 7400 ppm for lead and mercury
[[Page 10101]]
respectively. Based on these concentrations we determined that lead and
mercury in paint manufacturing wastes do not pose a threat to
ecological life. Based on our knowledge of paint formulations and
information we received on constituent concentrations from our 3007
survey, we do not expect paint production wastes to contain either lead
or mercury at the levels we predicted would pose a hazard to ecological
receptors. In addition, since lead and mercury are regulated as
hazardous wastes with the toxicity characteristic, we believe that
paint manufacturing wastes that have high levels of these constituents
will already be regulated as hazardous waste.\23\ Although we modeled
high concentrations in the waste, we believe that risks were not found
to ecological receptors in this screening level risk assessment because
of the small waste volumes of non-hazardous waste that are being
managed in the waste management units.
---------------------------------------------------------------------------
\23\ Such high levels of mercury in paint manufacturing are also
unlikely due to existing regulations controlling the use of mercury
in paint. Prior to the 1990s, paint manufacturing used mercury in
paints at low levels (e.g., phenylmercuric acetate was used as a
biocide to control mildew in latex paints). EPA restricted this use
under the Federal Insecticide, Fungicide and Rodenticide Act
(FIFRA), eliminating mercury in interior latex paints (55 FR 26754,
June 29, 1990) and in exterior paints (56 FR 105, May 31, 1991).
---------------------------------------------------------------------------
The models described in Section III were used to estimate the
release of these concentrations from the waste management units, fate
and transport of the constituents in the environment, and ultimately,
the concentration of each constituent in the different environmental
media (i.e., surface waters, soils). The ecological screening analysis
compares these modeled media concentrations to ecologically protective
media concentrations called chemical stressor concentration limits
(CSCL's). The result of this comparison is a ratio called a hazard
quotient. When the hazard quotient exceeds 1, there is potential for
adverse effects to the ecological receptor. If the hazard quotient is
equal to or less than 1, we do not expect adverse effects for a
particular ecological receptor. The amount by which the hazard quotient
exceeds 1 suggests the potential for adverse ecological effects;
however, the screening results do not demonstrate actual ecological
effects, nor do they indicate whether those effects will have
significant implications for ecosystems and their components.
a. How Were Ecological Exposures Estimated? Similar to estimating
human receptor exposures, we estimated ecological receptor exposures
based on simulated contaminant concentrations in the various
environmental media and food items, pathway specific ingestion rates,
and receptor type-specific body weights. For this analysis, however,
the EPA determined the upper bound constituent concentration that can
be present in the emission control dust, combined solids, and aqueous
waste and modeled the fate and transport of these constituents into the
environment. The resulting media concentrations were then compared to
ecological receptor chemical stressor concentration limits. The
exposure pathways included in this analysis were (1) root uptake of
constituents in soil or sediment by plants, (2) biological uptake of
constituents in surface water by aquatic animals (e.g., fish or aquatic
invertebrates); (3) biological uptake of constituents in sediment by
benthic invertebrates; (4) biological uptake of constituents in soil by
soil invertebrates; and (5) ingestion of constituents in surface water,
soil, sediment, or food items (plants and animals) by terrestrial
vertebrates. This assessment did not take into account the dermal
absorption of constituents in surface water or soil by terrestrial
vertebrates or the inhalation of volatile constituents in air. There
are not enough data available on these types of exposures to wildlife
to include them in this risk assessment. The 90th percentile media
concentrations were then compared to CSCLs to determine the hazard
quotient for each ecological receptor evaluated.
There were several simplifying assumptions made for this analysis
that over-estimated the potential hazard to ecological receptors. For
example, the exposures are estimated assuming that the receptors derive
all their food from the contaminated area and the receptors diets
consist predominantly of items with the highest contaminant uptake
rates. The methodologies and equations used for the ecological receptor
exposure estimates are fully described in the Technical Background
Document for the risk assessment.
b. What Ecological Receptors Did The EPA Evaluate? Two general
types of receptors were evaluated in the ecological assessment. For
exposure through direct contact with contaminated media, the receptors
were multispecies communities such as the soil invertebrate community
or the terrestrial plant community. For indirect exposure through
ingestion, the receptors are single species populations, such as white-
tailed deer or raccoons and include representative trophic levels and
feeding strategies. Evaluating risk to receptor populations and
communities included consideration of both aquatic and terrestrial
habitats. Within each habitat, risk was evaluated at all trophic levels
(i.e., position within the food chain) and for all feeding strategies
(e.g., plant feeder, predator). Although actual WMU sites were not
defined, it was assumed that WMUs occur in a variety of settings that
include terrestrial, wetland, and aquatic systems. Thus, the ecological
receptors evaluated in this risk assessment include representative
plants and animals from several different terrestrial, wetland, and
aquatic habitats. In general, the receptors occur throughout most of
the continental United States or throughout broad regions, such as east
of the Mississippi River.
Relevant trophic levels and feeding strategies (i.e., herbivorous,
omnivorous, and carnivorous diets) were established using simple food
webs that describe dietary composition and predator-prey relationships
in each of the three habitat types. Receptors representing each feeding
strategy at each trophic level were selected. In addition, the
receptors represent a cross section of general taxa at each trophic
level. For example, invertebrates as well as vertebrates were included,
and vertebrate receptors include amphibians, mammals, and birds.
The ecological assessment does not specifically address federally
listed threatened or endangered species.
c. How Did EPA Consider The Toxicity of Constituents in The
Ecological Risk Assessment? The calculation of ecological risk for
receptor populations is based on the implicit assumption that each
receptor species forages only within the contaminated area, regardless
of the size of its home range. For smaller animals, this assumption has
little impact on the estimates of exposure. However, for larger animals
with more extensive foraging areas, this assumption may overestimate
exposure if the animal's foraging patterns tend to be evenly spread
over the home range that extends beyond the contaminated area.
For the species specific receptors (both mammals and birds), the
overall approach used to establish ecotoxicological benchmarks is
similar to the methods used to establish RfDs for humans. Each method
uses a hierarchy for the selection of toxicity data and extrapolates
from a test species to the species of interest. However, there are
fundamental differences in the goals of noncancer risk assessments for
humans and ecological receptors. Risk assessments of humans seek to
protect the individual while risk assessments of ecological receptors
seek to protect
[[Page 10102]]
populations or communities of important species.
First, because population viability was selected as an assessment
endpoint, the benchmarks were developed from measures of reproductive/
developmental success or, if unavailable, other effects that could
conceivably impair population dynamics. In addition, the population-
level benchmark was preferred over population-inference benchmarks.
Population-level benchmarks are based on studies of effects on an
entire population (i.e., many interacting individuals) while
population-inference benchmarks are based on studies of individuals
with protection of the population being inferred from protection of the
individual (e.g., no observed adverse effect levels for individual
organisms on reproductive endpoints). Although relatively few
population-level benchmarks have been developed to date, these
benchmarks are considered to be more rigorous than the point estimates
gleaned from toxicity studies. Once the appropriate ecotoxicological
studies were identified for mammals and/or birds, the CSCLs for each
receptor were calculated for each medium of interest by scaling the
toxicity benchmark from the test species to the receptor species,
identifying the uptake/accumulation factors, identifying the exposures
from dietary intake, and determining a risk-based concentration in each
media. The benchmarks for the community receptors were taken from
various sources such as the final chronic values developed for the
National Ambient Water Quality Criteria. A detailed description of the
benchmarks developed for all of the receptors evaluated is contained in
the Technical Background Document for the risk assessment.
7. Did EPA Conduct a Peer Review of The Risk Assessment? The Agency
has obtained a peer review from independent experts. Their comments
have been received and are part of the peer review document that is in
the docket for today's proposed rule. The peer review document also
describes how the experts were identified and selected, contains
information on the experts experience and employment, and provides a
copy of the questions the peer reviewers were asked to address. Due to
the time constraints for proposal of this rule, the Agency has not yet
reviewed and addressed those comments. Both the peer review comments
and the public comments will be addressed in the final rulemaking.
IV. Proposed Listing Determinations and Regulations
A. What Are The Proposed Regulations for Paint Production Wastes?
We are proposing that, if you generate any of the paint
manufacturing wastes described in these listings, then you must
determine whether or not your waste is a listed hazardous waste, or you
must assume that it is hazardous. For the wastes identified in the K179
and K180 listings, your waste would become a listed hazardous waste if
it contains any of the constituents of concern at a concentration equal
to or greater than the hazardous concentration identified for that
constituent. You would need to make a determination that all the
constituents of concern in your waste are below the hazardous
concentrations to have your wastes remain nonhazardous. Waste liquids
listed in K180, however, would not be subject to the listing, if the
wastes are stored or treated exclusively in tanks or containers prior
to discharge to a POTW or under an NPDES permit. We are proposing the
following regulatory language in Sec. 261.32 for these wastes:
K179--Paint manufacturing waste solids generated by paint
manufacturing facilities that, at the point of generation, contain
any of the constituents identified in paragraph (b)(6)(iii) of this
section at a concentration equal to or greater than the hazardous
level set for that constituent in paragraph (b)(6)(iii) of this
section. Paint manufacturing waste solids are: (1) Waste solids
generated from tank and equipment cleaning operations that use
solvents, water and/or caustic; (2) emission control dusts or
sludges; (3) wastewater treatment sludges; and (4) off-specification
product. Waste solids derived from the management of K180 by paint
manufacturers would also be subject to this listing. Waste liquids
derived from the management of K179 by paint manufacturers are not
covered by this listing, but such liquids are subject to the K180
listing. For the purposes of this listing, paint manufacturers are
defined as specified in paragraph (b) of this section.
K180--Paint manufacturing waste liquids generated by paint
manufacturing facilities that, at the point of generation, contain
any of the constituents identified in paragraph (b)(6)(iii) of this
section at a concentration equal to or greater than the hazardous
level set for that constituent in paragraph (b)(6)(iii) of this
section unless the wastes are stored or treated exclusively in tanks
or containers prior to discharge to a POTW or under a NPDES permit.
Paint manufacturing liquids are generated from tank and equipment
cleaning operations that use solvents, water, and/or caustic. Waste
liquids derived from the management of K179 by paint manufacturers
would also be subject to this listing. Waste solids derived from the
management of K180 by paint manufacturers are not covered by this
listing, but such solids are subject to the K179 listing. For the
purposes of this listing, paint manufacturers are defined as
specified in paragraph (b) of this section.
Due to the uncertainties in our assessment of the management of
paint manufacturing waste liquids in surface impoundments, we are
seriously considering an alternative proposal not to list paint
manufacturing waste liquids. We describe this alternative and our
reasoning for this option later in this notice (see Section IV.D).
Under the proposed listings shown above, paint manufacturing wastes
with constituents of concern below the concentration limits at the time
of generation would not be hazardous waste K179 or K180; such wastes
would be nonhazardous from their point of generation, and would not be
subject to any RCRA Subtitle C management requirements for generation,
storage, transport, treatment, or disposal (including the land disposal
restrictions). Similarly, liquid paint manufacturing wastes would also
be nonhazardous if the waste is managed or treated exclusively in tanks
or containers prior to discharge to a POTW or under an NPDES permit
regardless of whether it contained any of the constituents of concern.
However, if paint manufacturing wastes are hazardous waste due to
another listing code or because they exhibit a hazardous waste
characteristic under section 261.24, the wastes remain hazardous under
these other regulations.
We are proposing that the constituents and the concentrations in
the two above listings (which would be specified in paragraph
(b)(6)(iii) of Sec. 261.32) would be those shown in Tables IV.A-1 for
waste solids (K179) and in Table IV.A-2 for waste liquids (K180). These
are waste concentrations that represent risk-based concentrations for
constituents we determined to be of potential concern in paint
manufacturing wastes. The concentration-based listing levels for waste
solids are based on the risk modeling for landfills, and the levels for
waste liquids are based on the risk modeling for surface impoundments.
We also evaluated potential air releases from treatment of waste
liquids in tanks, but as described in Section IV.C, we did not find
significant risks for this management scenario. Therefore, we are
proposing not to include wastes managed exclusively in tanks within the
scope of the listing for waste liquids. See Section IV.D for further
discussion of our reasoning for structuring the listing for waste
liquids in this way, and for other options we are considering.
[[Page 10103]]
As described in Section III.E, we developed risk-based
concentrations for the larger set of constituents shown in Table III.E-
4. In general, we relied on the modeling results to guide us in
deciding which constituents would be most useful in defining these
paint manufacturing wastes as listed hazardous wastes. We chose
constituents for listing from the list in Table III.E.4 using a number
of criteria.
We dropped constituents from further concern if the
risk-based levels for the waste exceeded or approached 100% (i.e.,
1,000,000 mg/kg), because these constituents could not present
significant risks in the paint manufacturing wastes we evaluated.
We did not include constituents that are already
regulated by the TC. As discussed in Section IV.G, we found that the
regulatory TC levels (see 40 CFR 261.24) would likely be below the
protective levels we calculated for these chemicals. Therefore,
based on our analysis, the existing TC regulations adequately
regulate risks from these constituents in these wastes, because
wastes exhibiting the TC would have to be treated prior to disposal.
We dropped constituents if their levels were so high
that we believe it is highly unlikely that these chemicals would
ever exist at such levels in waste solids from paint manufacturing.
For paint manufacturing waste solids (K179) we used the risk levels
in Table III.E-4 calculated for emission control dust, because these
were slightly lower than the levels for the combined solids. Using the
above criteria for the 43 constituents listed in Table III.E-4, we
dropped 24 constituents that have risk-based levels above 100% and 11
other constituents that are TC chemicals. We dropped three others that
are unlikely to exist in paint wastes at the calculated risk-based
levels. Two of the three have risk-based levels that are close to 100%
and are therefore implausible for waste (n-butyl alcohol--970,000 mg/
kg, formaldehyde--930,000 mg/kg). The other constituent, methylene
chloride (dichloromethane), has a level of 24% (240,000 mg/kg). This
appears unlikely, given that manufacturers have moved away from using
chlorinated solvents in paints. This is further supported by the
responses to the 3007 survey, which showed that the presence of this
chemical was not reported by any facility in nonhazardous waste.
For waste liquids (K180), we used the risk-based levels in Table
III.E-2 derived for wastewaters in surface impoundments. We dropped 14
constituents that have risk-based levels above 100% and 13 others that
are TC constituents. We also dropped four other constituents that have
levels that appear unlikely for waste liquids: ethylene glycol, phenol,
methanol, and 2,4-dimethylphenol. The calculated levels for ethylene
glycol (790,000 mg/L), phenol (270,000 mg/L) and methanol (200,000 mg/
L) were so high that we considered these unlikely to ever occur in
liquid paint manufacturing wastes. While all three are potentially used
as water-soluble solvent ingredients, phenol and methanol are also used
as biocides in water-based paints.\24\ While the Survey showed these
chemicals were found frequently in paint manufacturing wastes, no
generator reported levels in nonhazardous or hazardous wastes that
would approach the modeled levels of concern (the only waste with high
levels was an off-spec paint containing 20% of ethylene glycol that was
sent to fuel blending). For waste streams to approach these
concentrations, the constituents would have to start out at even higher
concentrations in the product. Such high levels in the products are
unrealistic, because products with such high concentration of these
constituents would not have the attributes of paint. Therefore, we are
not proposing to include these chemicals as constituents in the paint
listings.\25\
---------------------------------------------------------------------------
\24\ We found solvent uses for phenol were limited in a listing
determination for solvent uses of this chemical (see 61 FR 42318,
August 14, 1996). Primary uses as a solvent were in the petroleum
industry (extraction of lube oil) and in microelectronic and
automotive industries (removing coatings). While this previous
analysis did not focus on uses as ingredient, which is the potential
use in paint formulations, this indicates that the use of phenol for
its solvent properties is relatively rare.
\25\ The proposed levels are based on the probabilistic risk
results for the 90th percentile. If we were to use the results for
the 95th percentile, we would consider including methanol, because
then the listing level for liquid wastes would drop to 6.2%, which
we believe is somewhat more likely.
---------------------------------------------------------------------------
We dropped 2,4-dimethylphenol as a constituent of concern for waste
liquids because the 3007 Survey showed that facilities did not report
its presence in nonhazardous waste. Furthermore, the only potential use
in paint we found for this chemical was possibly as a biocide.
Therefore the low concentrations resulting from such a use would be
unlikely to approach the risk-based level (17,000 mg/L). We also note
that the TRI data showed only minimal releases (5 lbs.) to off-site
wastewater treatment for all facilities in SIC code 2851.
Regulations that limit air releases from off-site wastewater
treatment facilities are also likely to keep levels of these organic
constituents below such high levels. EPA is planning to propose a MACT
standard for paint manufacturers (Miscellaneous Organic Chemical and
Coatings Manufacturing) that would regulate HAPs in wastewaters, both
when managed on-site and when sent off-site for treatment. Furthermore,
subpart DD in 40 CFR part 63 sets National Emission Standards for
Hazardous Air Pollutants (NESHAP) from off-site waste and recovery
operations, which may include off-site centralized wastewater treatment
facilities (July 1, 1996, 61 FR 34140 ).\26\ In addressing potential
air releases from such facilities, the CAA regulations are likely to
prevent the levels of most chemicals at issue here (e.g., phenol and
methanol) from reaching the risk-based levels under consideration in
liquid paint manufacturing wastes. This is likely because such MACT
standards often provide incentives to reduce HAPs through source
reduction or pretreatment to avoid costly engineering controls.
---------------------------------------------------------------------------
\26\ EPA concluded that this group of wastewater treatment
plants would likely include some facilities that would be major
sources of HAPs (see 61 FR 34144/2). Thus, these major sources would
be subject to the MACT standard.
---------------------------------------------------------------------------
We solicit comment on the proposed list of constituents and their
levels. We seek comment and supporting information as to whether any
other constituents discussed above should be added to the chemicals for
listing paint solids or liquids and the basis for such action. We seek
any information that may assist us in deciding whether any of the
constituents or levels in Tables IV.A-1 and IV.A-2 are so unlikely to
be present at the levels of concern that we should drop them from the
listing. For example, the levels for the solids (K179) are high for
methyl isobutyl ketone (73,000 mg/kg). The liquid level for
formaldehyde (82,000 mg/L) is also unlikely for a chemical that has
been used mainly as a biocide or in polymer binders. In addition, we
question whether the chemicals methyl methacrylate and styrene, which
are used primarily as resins rather than in their monomeric forms,
would be present at the high levels shown in Tables IV.A-1 and IV.A-2
for the solid or liquid paint manufacturing wastes. However, we believe
levels of the monomeric forms of acrylonitrile and acrylamide that are
present in the resins may still present a potential risk at the
relatively low levels set for waste solids and waste liquids not
managed in tanks. Therefore, we are proposing to include acrylonitrile
and acrylamide as listing constituents, because they may be in paint
manufacturing wastes at or above these levels (see discussion in
Section IV.C on potential risks from tanks). Depending on comments, we
may choose to add or remove constituents from the concentration-based
listing.
[[Page 10104]]
As required under Sec. 261.30(b), we are proposing to add the
constituents that are the basis for the listings to Appendix VII of
Part 261. We are proposing to add the constituents in Table IV.A-1 for
K179 and the constituents in Table IV.A-2 for K180. In addition, a
number of constituents in Tables IV.A-1 and IV.A-2 are not currently
listed in Appendix VIII to Part 261 as ``hazardous constituents.'' EPA
places constituents on Appendix VIII if scientific studies show the
chemicals have toxic, carcinogenic, mutagenic, or teratogenic effects
on humans or other life forms (see Sec. 261.11(a)(3)). The Risk
Assessment Background Document contains the detailed toxicological data
for all constituents we evaluated, including the chemicals we are
proposing to add to Appendix VIII: n-butyl alcohol, ethyl benzene,
methyl isobutyl ketone, styrene, and xylene. If we choose the
alternative of not listing paint manufacturing waste liquids (K180),
then we would not need to add the constituents to Appendix VII for
K180, and we would need to add only methyl isobutyl ketone to Appendix
VIII.
Table IV.A-1.--Concentration Levels for Waste Solids (K179)
------------------------------------------------------------------------
Concentration
Constituent levels (mg/
kg)
------------------------------------------------------------------------
Acrylamide............................................... 310
Acrylonitrile............................................ 43
Antimony................................................. 2,300
Methyl Isobutyl Ketone................................... 73,000
Methyl methacrylate...................................... 28,000
------------------------------------------------------------------------
Table IV.A-2.--Concentration Levels for Waste Liquids (K180)
------------------------------------------------------------------------
Concentration
Constituent levels (mg/L)
------------------------------------------------------------------------
Acrylamide............................................... 12
Acrylonitrile............................................ 9.3
Antimony................................................. 390
Ethylbenzene............................................. 11,000
Formaldehyde............................................. 82,000
Methyl Isobutyl Ketone................................... 340
Methyl Methacrylate...................................... 2,100
Methylene Chloride....................................... 4,500
N-Butyl Alcohol.......................................... 41,000
Styrene.................................................. 4,600
Toluene.................................................. 1,200
Xylene (mixed isomers)................................... 3,900
------------------------------------------------------------------------
The listing levels we are proposing for K179 and K180 are different
for the waste solids and waste liquids. These levels are based on the
risk assessment for various scenarios for disposal of solids (landfill)
and the liquids (surface impoundment). In general, we believe
generators will be able to readily determine which waste category their
wastes would be in, based on their responses to the 3007 Survey, and
their reported management practices. However, we are considering
setting a clear definition to distinguish the waste solids and liquids,
such that a generator can readily determine which listing applies.
Thus, we request comment on several options in establishing a clear
definition that would distinguish solids vs. liquids.
Perhaps the most straightforward approach would be to set a level
of percent solids above which the waste would be a solid paint
manufacturing waste and below which it would be a liquid paint
manufacturing waste. One possible level could be 15%. Thus, this option
would define paint manufacturing waste solids as those containing 15%
or above solids (by weight). This cutoff reflects the general approach
we used in our modeling for solids. In our assessment of releases from
landfills we assumed that the waste contained a maximum moisture level
of 85% (for sludges; we assumed a maximum moisture level of 15% for
dusts). Furthermore, because of the restrictions on free liquids in
municipal nonhazardous landfills (e.g., see Sec. 258.28), we do not
envision wastes containing less than 15% solids could reasonably be
managed in a landfill. Therefore, we believe that wastes containing
less than 15% solids will be managed in units associated with
wastewater treatment, such as tanks or surface impoundments. In
addition, in most cases water will be separated from solids as part of
routine wastewater treatment. Thus, generators would be evaluating
solid residues, which clearly meet our solid definition, or treated
water, which would typically be discharged to a POTW or under an NPDES
permit, and would not be covered by the K180 listing in any case.
Percent solids could be measured by an established method, such as
the method for total suspended solids (TSS) described in EPA guidelines
for test methods used under the CWA (EPA method 160.1 in 40 CFR 136.3,
Table 1B).\27\ However, generators may have the knowledge necessary to
decide whether their paint manufacturing waste was a liquid or a solid,
based on past analysis or disposal practices. We believe that in many
cases, especially for wastes that are clearly ``wet'' or ``dry,'' the
generator can easily tell from a visual inspection that solids content
is well above or below 15%. Thus, if we were to set a level to define
paint manufacturing waste solids and liquids, we believe we could allow
the generator to use his knowledge, rather than necessarily requiring a
test.
---------------------------------------------------------------------------
\27\ Another option would be to use section 7.1 in the TCLP
(method 1311) to measure filterable solids.
---------------------------------------------------------------------------
Instead of setting a specific level of percent solids, another
option is to use the Paint Liquids Filter Test (method 9095 in SW-846)
to determine if the waste is a liquid or a solid. A paint manufacturing
waste found to contain free liquid under this method would be
considered a liquid, and would be evaluated under the K180 listing,
while a paint manufacturing waste that does not contain free liquids
would be subject to the K179 listing. This method appears logical
because it is presently used in defining the term ``liquid waste'' in
the solid waste disposal criteria for determining compliance with the
prohibition on disposing of bulk or containerized liquid in municipal
landfills (Sec. 258.28). Method 9095 is also used in a similar way for
hazardous waste landfills (Sec. 264.313(c)). Thus, using this method to
distinguish paint manufacturing waste solids from liquids would be
consistent with the definitions used in the operating practices for the
management scenario modeled for solids, i.e., landfills.
A third option would be to use a definition of liquids that is
analogous to the definition of wastewater used under the land disposal
restrictions. Wastewater is defined as waste with less than 1% total
suspended solids (TSS) and less than 1% total organic carbon
(Sec. 268.2(f)); nonwastewater is defined as any waste that is not
wastewater. While using this approach would allow some consistency in
definitions in the listings and the LDR programs, we believe this would
not be appropriate. A key disadvantage of this approach is that it
defines wastes with greater than 1% TSS as a nonwastewater, i.e., a
solid, even though such a waste is highly likely to be managed in
wastewater treatment systems using tanks and surface impoundments, and
not landfills. Given this problem, we do not think using this
definition would be useful to define wastes solids and liquids for
purposes of the paint listings.
We seek comment on the need for specific definitions for paint
manufacturing waste liquids and solids, and the relative merits of the
above options or similar approaches. We also request comment on whether
facilities are likely to have information available on the percent
solids in their wastes.
[[Page 10105]]
B. Why Are We Proposing to Use the Level of Constituents in the Waste
Solids as Total Waste Concentrations Rather Than Leachate
Concentrations?
We are proposing to set the concentration levels for defining
hazardous paint solids using the concentrations measured in the waste
itself, i.e., the totals concentration.\28\ We considered using the
landfill leachate levels instead of the waste levels to define the
listed waste. Using landfill leachate levels would require generators
to evaluate their wastes using a test such as the Toxicity
Characteristic Leaching Procedure (TCLP).\29\ However, we decided not
to use the TCLP approach for a number of reasons. We believe that the
partitioning model used to establish the totals concentrations is a
more appropriate tool to assess risks posed by the paint manufacturing
wastes. This is because the partitioning model factors in periodic
placement of the specific waste volumes in cells within the landfill,
closure of the landfill after 30 years, volatilization of constituents
from the landfill through partitioning to the air, and any degradation
of organics while in the unit. The leaching values for the paint
manufacturing waste solids result from the partitioning of constituents
from the waste to water infiltrating the unit. A test method like the
TCLP does not reflect these factors. The TCLP approach is designed only
to assess groundwater impacts, and does not account for other releases
or processes occurring in landfills. Therefore, the estimated leaching
numbers derived from our modeling assessment of paint manufacturing
wastes, where partitioning and degradation are occurring before the
constituents leave the unit, are not strictly comparable with the
simple leaching of constituents from wastes represented by the TCLP.
---------------------------------------------------------------------------
\28\ This is not an issue for the listing for paint liquid
wastes, because any analysis of the liquids would include an
analysis of the total liquid mixture.
\29\ See method 1311 in OSW's methods manual, Test Methods for
Evaluating Solid Waste, Physical/Chemical Methods, SW-846.
---------------------------------------------------------------------------
We recognize that the totals levels appear somewhat high in
comparison to the leachable levels we calculated for our assessment of
paint manufacturing wastes (Table IV.-3). For example, the leaching
level calculated for dichloromethane is 390 mg/L, compared to a total
level of 240,000 mg/kg. However, it is not surprising that leachate
levels derived from the waste would be lower than the levels in the
waste itself. Most of the organic constituents assessed are relatively
volatile, and will begin to volatilize as they are placed in the
landfill. The entire mass of constituent in the waste is not placed in
the landfill at once, but rather is placed in cells over the life of
the unit. Therefore, as disposal occurs, the waste constituents are
continuing to partition into air, soil, or leachate. Our model also
factors in degradation of organics in the landfill. Such biodegradation
is relatively slow for most chemicals, however this also assists in
attenuating the levels of constituents that are released to the
subsurface. We recently published related modeling results as part of
the Hazardous Waste Identification Rule (HWIR) using the same modeling
approach (64 FR 63382, November 19, 1999, and 65 FR 44491, July 20,
2000), though this effort covered a wider distribution of waste
volumes. The use of totals rather than leachate for a concentration-
based listing is also consistent with another recent EPA proposal for
listing hazardous waste from the Dye and Pigments industry (64 FR
40192, July 23, 1999).
Therefore, we are proposing the concentration levels for the waste
itself for the listing for waste solids from paint manufacturing.
However, we seek comment on the option of setting the leachate
concentrations from our modeling as the listing levels for the paint
solids, and on the potential impacts (incremental costs and benefits)
of such an approach. We may still consider a final regulation based on
the measurement of leachate with the TCLP method, as shown in Table
IV.B-3, after further consideration and review of comments.
Table IV.B-3.--Alternative Concentration Leaching Levels for Waste
Solids (K179)
------------------------------------------------------------------------
Concentration
Constituent levels (mg/
L)
------------------------------------------------------------------------
Acrylamide............................................... 0.70
Acrylonitrile............................................ 0.91
Antimony................................................. 58
Methyl Isobutyl Ketone................................... 42
Methyl methacrylate...................................... 160
------------------------------------------------------------------------
C. Why Are We Proposing to Exclude Waste Liquids Managed in Tanks?
We are proposing that liquid paint manufacturing wastes stored or
treated exclusively in tanks or containers prior to discharge to a POTW
or under an NPDES permit not be subject to today's proposed listing
because these wastes managed in tanks do not pose sufficient risk to
warrant hazardous waste regulation.
As shown in Table III.D-4, nearly all of the liquid paint
manufacturing wastes are managed in some type of wastewater treatment
system (small volumes are sent to fuel blending or other treatment).
Furthermore, as indicated in Table III.D-4, liquid wastes are primarily
classified as water or caustic cleaning liquids, except for one small
volume of solvent cleaning liquid that went to a fuel blender.
For on-site tanks, as described in Section III.E, we conducted a
bounding risk analysis for on-site treatment tanks that evaluated the
worst case scenario for on-site management in tanks, including storage
as well as treatment tanks. Our analysis identified some potential
constituents of concern: Benzene, chloroform, mercury, methylene
chloride, tetrachloroethylene, and acrylonitrile. However, when the
survey responses provided data on constituent levels, these data
indicated that these constituents are unlikely to be present in these
wastes at levels of concern. In addition, for benzene, chloroform,
mercury, and tetrachloroethylene, the risk-based concentrations derived
from the bounding risk analysis are significantly higher than the
respective TC levels; therefore, the TC regulations provide some
control for most of these constituents. For acrylonitrile, the
calculated risk-based concentration of 1,500 ppm is significantly
higher than the projected range of concentration of 1-40 ppm for
acrylonitrile in liquid waste streams; as such, it is not of concern.
Most other constituents of concern either bounded out (i.e., modeled
levels were higher than 1,000,000 ppm), or were unrealistically high
for paint manufacturing wastes. The risk-based levels derived from the
risk assessment for methylene chloride, methyl isobutyl ketone,
toluene, vinyl acetate, and xylene are so high that we believe they are
highly unlikely to exist at such levels in nonhazardous liquid paint
manufacturing wastes. This evaluation for on-site tanks is discussed in
more detail in the following section (IV.C.1).
For off-site treatment tanks, we conducted a probabilistic risk
assessment as described in Section III.E. This risk assessment
identified three potential constituents of concern: Mercury, benzene
and acrylonitrile. The survey responses showed that these constituents
are not likely to be present in the wastes at concentrations of
concern. In addition, the levels of mercury and benzene in the waste
are also limited by the existing TC regulations, i.e., the risk-based
levels derived from the risk assessment are
[[Page 10106]]
well above the TC levels. As described below, we determined that
acrylonitrile is unlikely to exist in paint manufacturing waste liquids
at the risk-based levels of 69,000 ppm. Therefore, there is no need to
regulate paint manufacturing waste streams managed in off-site
treatment tanks. See section IV.C.2 for a full discussion.
1. On-Site Storage and Treatment Tanks
Based on our extrapolated survey results, we estimate that 14,564
metric tons (approximately 47%) of nonhazardous liquid paint
manufacturing wastes generated are managed in on-site storage tanks and
7,514 metric tons, or approximately 24%, of nonhazardous paint
manufacturing waste liquids are managed in on-site treatment tanks.
After these wastes are managed on-site in storage and treatment tanks,
the wastes are then either directly discharged into a waterway under a
NPDES permit, discharged into a POTW, or sent to centralized wastewater
treatment facilities.
For tanks, we normally model air emissions. We assume that
significant groundwater risks are unlikely because tanks do not leak
liquids into the soil if properly maintained. Treatment tanks represent
a more conservative scenario for modeling purposes because they are
typically used for the aeration and flocculation of liquid wastes to
settle out solids, causing more constituents to escape into the air
than the relatively quiescent accumulation of liquids in storage tanks.
Accordingly, we evaluated the potential risks from the management of
liquids in treatment tanks to cover both scenarios.
As described earlier in Section III.E, we conducted a bounding
analysis of the potential air releases from the nonhazardous liquid
wastes treated in on-site treatment tanks. This conservative analysis
assumed tanks are uncovered, and modeled the largest liquid residual
volume and tank size reported by the surveyed facilities. The risk-
based levels for most constituents exceeded 100%, and would not present
significant risks in the paint manufacturing wastes for this scenario.
The risk assessment results showed somewhat lower risk-based
concentrations for paint manufacturing wastes in tanks for some
constituents, i.e., benzene (1,100 ppm), chloroform (15,000 ppm),
mercury (41 ppm), tetrachloroethylene (22,000 ppm), acrylonitrile
(1,500 ppm), methylene chloride (17,000 ppm), methyl isobutyl ketone
(780,000 ppm), toluene (120,000 ppm), vinyl acetate (100,000 ppm), and
xylene (830,000 ppm); we discuss these chemicals in detail below.
In general we do not expect significant levels of organic chemicals
in on-site wastewater treatment systems for several reasons. First, the
liquid wastes most likely to have high organic content, solvent
cleaning wastes, are managed as hazardous. Except for one facility,
these wastes were coded as hazardous waste, either due to a
F-listing or because of a characteristic. The 3007 survey showed that
all the generators of hazardous waste liquids reported the wastes were
treated by incineration, fuel blending, or they were reused. Therefore,
we have no data suggesting facilities are treating such high organic
liquids in on-site wastewater treatment systems.
Second, the 3007 survey shows that none of the small number of
facilities that treated wastes in on-site wastewater treatment (WWT)
tanks (8 facilities, representing about 18 facilities in our weighted
sample) reported significant organic content in their wastes. Of the 8
facilities, only one reported the presence of any organic constituents
of potential concern, but listed them only because they may
occasionally be present in the waste. Of the other 7 facilities, most
reported the presence of metals, a few reported vinyl acetate polymers,
and one reported the water-soluble ethylene glycol.
Finally, as noted in Section IV.A above, a MACT standard covering
paint manufacturers will soon be proposed that will address potential
air releases from these facilities. The MACT would place limits on HAPs
in wastewater treatment systems, and would likely keep organic levels
in paint manufacturing wastewaters relatively low.
Turning to the constituents of possible concern (benzene,
chloroform, mercury, methylene chloride, tetrachloroethylene, and
acrylonitrile), the facilities reported in their survey responses that
these chemicals were either not present at all, or were present at only
trace concentrations. Out of the 187 paint manufacturers surveyed, the
responses showed benzene was present in trace amounts in only one
facility's nonhazardous water cleaning liquid; mercury was present in
only two facilities' nonhazardous water cleaning liquid at trace levels
(up to 0.06 ppm). No facility reported the presence of any chloroform,
methylene chloride, or tetrachloroethylene in any liquid residual. We
discuss the possible presence of acrylonitrile in detail below.
Furthermore, the risk-based levels for most of these constituents are
well above their TC levels (benzene-0.50 ppm, chloroform-5.0 ppm,
mercury-0.2 ppm, and tetrachloroethylene-0.7 ppm). Consequently, we are
not proposing regulating these constituents under today's proposed
listing.
Acrylonitrile is a monomer, i.e., a relatively small compound with
low molecular weight. It reacts with other monomers to form polymers
(i.e., cross-link into large, high molecular weight compounds) that are
used as paint binders. However, the reaction is rarely 100% complete,
and small amounts of the individual monomers remain unreacted as
impurities in the polymer. Unreacted acrylonitrile monomers, not their
polymers, are the targeted constituents of concern in our risk
assessment.
With respect to acrylonitrile monomers, we do not expect this
constituent to be present in paint manufacturing wastewaters above the
risk-based concentrations derived from the bounding analysis for tanks.
To analyze whether concentration levels of acrylonitrile at 1,500 ppm
are reasonable as a basis for listing liquids in on-site tanks, we
developed a methodology to determine whether these constituents are
likely to occur in paint manufacturing waste liquids at concentrations
within the range of the risk-based levels. We assessed potential
concentrations of acrylonitrile in paint manufacturing liquid waste
streams in a three-step process that involved tracking the monomers
from point of origin (binder) to the final destination (liquid waste
streams): (1) We estimated the concentration range of acrylonitrile
monomers in the binder systems used to make paint; (2) we estimated the
volume percentage of the binder systems added into paints themselves;
and, (3) we estimated the monomer concentration range in paints in tank
cleaning wastes. Based on these calculations (which are discussed in
more detail below), we estimated that the ranges of acrylonitrile
monomer concentrations in the liquid waste streams should be one to 40
ppm. We then compared these projected concentration ranges of
acrylonitrile in the liquid waste streams to the risk-based levels
calculated in the risk assessment.
As specified above, we estimated the likely range of unreacted
monomer of acrylonitrile in the binders (i.e., polymers) to be between
20 ppm and 1,000 ppm. This is reflected in our analysis of the use of
acrylamide and acrylonitrile polymers in paint formulations \30\ and
the Material Safety
[[Page 10107]]
Data Sheet (MSDS) data we obtained from some paint manufacturers
(copies available in the public docket for today's proposed rule),
which show the monomer mixture in binders in the 500 to 1,000 ppm
range. Second, we projected that the likely concentration ranges of
monomers in a paint or coating are approximately 10 ppm to 500 ppm for
acrylonitrile. This estimate was based on our examination of paint
formulations, which indicates that these paint formulations contain up
to 50% by weight of acrylonitrile-acrylic polymer.\31\ Finally, we
estimated the projected monomer concentration in the resulting water
cleaning liquids is approximately one ppm to 40 ppm for acrylonitrile
given that approximately 50 gallons of water are needed to wash a
typical paint mixing tank of approximately 5 feet in diameter and 8
feet in height with a paint depth of 6 feet,\32\ and that a 0.0625-inch
film of paint is attached to the inside surface of the tank up to 6
feet (amounting to a total of 4 gallons of paint to be rinsed). These
projected acrylonitrile concentrations in paint manufacturing
wastewaters are significantly lower than the calculated risk-based
concentration of 1,500 ppm. For more details, see ``Potential
Acrylonitrile Concentrations in Paint Manufacturing Liquid Waste
Streams' in the public docket for today's proposed rule. Therefore, we
believe it is highly unlikely for this constituent to be present in
paint manufacturing liquid waste streams at such levels.
---------------------------------------------------------------------------
\30\ See the memo from Paul Danault, Dynamac Corporation, to
David Carver and Cate Jenkins, EPA, dated September 6, 2000, which
is in the docket for today's proposed rule.
\31\ Ibid.
\32\ That is, 50 gallons of water used for washing per about 800
gallons of paint produced in the tank. This is a conservative
assumption compared to the information in Reference 7 of the
Bibliography, Development Document for Effluent Limitations
Guidelines and Standards for the Paint Formulating Point Source
Category, EPA 440/1-79/049B, which states that the median wastewater
generation at waterbone paint facilities is 0.2 gallons per gallon
of paint produced.
---------------------------------------------------------------------------
In addition, according to the information available to us,
acrylonitrile is not widely used in the U.S. paint manufacturing
industry, and its use is diminishing. For example, resin manufacturers
are marketing ``acrylonitrile free'' resins. It is also a practice
within the resin manufacturing industry to remove residual monomer
before selling the polymer for paint production.
The low use of this binder in paints is supported by our survey
data. Six of 187 surveyed paint manufacturing facilities reported
acrylonitrile-derived polymers in their nonhazardous liquid residuals
(in particular nonhazardous water cleaning liquids). In addition, one
survey response indicated the presence of acrylonitrile and
acrylonitrile-derived polymers in the nonhazardous water cleaning
liquids at 2.8%. Assuming the polymers used by this facility include
the monomers in concentrations ranging from 20 ppm to x 1,000 ppm for
acrylonitrile as estimated above, the maximum monomer concentration in
this facility's nonhazardous wash water would be less than 28 ppm
(i.e., 2.83% x 1,000 ppm/acrylonitrile monomer in polymer), which is
consistent with our assessment (i.e., between 1 ppm to 40 ppm).
The risk-based levels derived from the risk assessment for methyl
isobutyl ketone (780,000 ppm, or 78%), toluene (120,000 ppm, or 12%),
vinyl acetate (100,000 ppm, or 10%), and xylene (830,000 ppm, or 83%)
are so high that we believe they are highly unlikely to exist at such
levels in nonhazardous liquid paint manufacturing wastes. This is
reflected in the responses to our Section 3007 survey, which indicated
that the highest levels of toluene, vinyl acetate and vinyl acetate-
derived polymers, and xylene in nonhazardous liquid residuals were
0.025 ppm, 16,000 ppm, and 118 ppm, respectively.
In conclusion, our analysis indicates there are no significant
risks posed by the modeled constituents in nonhazardous paint
manufacturing wastes that are managed in on-site storage and treatment
tanks. We believe the likely levels of the potential constituents of
concern in paint manufacturing wastewaters are substantially lower than
the risk-based concentrations derived from the bounding risk analysis.
Therefore, requiring the facilities to analyze or otherwise evaluate
these constituents would impose an unnecessary burden on paint
manufacturers. Thus, we are proposing that paint manufacturing waste
liquids stored and/or treated in on-site tanks at paint manufacturing
facilities are not subject to today's proposed listing.
2. Management of Liquid Paint Manufacturing Wastes in Off-Site
Treatment Tanks
Based on our extrapolated survey results, we estimate that 6,407
metric tons (approximately 21%) of liquid nonhazardous paint
manufacturing wastes generated are disposed off-site in privately owned
wastewater treatment facilities where tanks and surface impoundments
may be used as part of the treatment process. Following treatment, the
wastes are typically discharged into surface waters under an NPDES
permit, or discharged to the POTW system.
As described earlier in Section III.E, the risk assessment
conducted for liquid paint manufacturing wastes managed in off-site
treatment tanks identified potential inhalation risks associated with
only a few constituents. The risk assessment estimated risk-based
concentrations for mercury (10,000 ppm), benzene (190,000 ppm) and
acrylonitrile (69,000 ppm).
As discussed above, the survey showed that facilities reported only
traces of benzene or mercury in a few nonhazardous liquid residuals.
Furthermore, levels of both constituents are controlled by the existing
TC regulations. Therefore, there is no need to regulate these TC
constituents further under today's proposed listing.
For acrylonitrile, the risk-based concentration of 69,000 ppm is
significantly higher than the estimated range of acrylonitrile monomer
in paint manufacturing wastewaters (see previous discussions on liquid
wastes managed in on-site storage and treatment tanks). Therefore, it
is highly unlikely for this constituent to be present in paint
manufacturing liquid waste streams at such a high level.
We note that 21 of the 187 surveyed paint manufacturing facilities
reported that they sent nonhazardous liquid wastes to off-site
wastewater treatment facilities, of which only one reported having any
of the three constituents of concern in the wastewater. Specifically,
this facility sent a very small quantity of nonhazardous wash water
(151 gallons/year) containing an unknown amount of acrylonitrile to a
centralized wastewater treatment facility.
In conclusion, we believe there are no significant risks posed by
the modeled constituents in nonhazardous paint manufacturing wastes
that are managed in off-site treatment tanks. We believe the levels of
the potential constituents of concern in paint manufacturing
wastewaters are substantially lower than the risk-based concentrations
derived from the risk assessment. Therefore, requiring the facilities
to analyze or otherwise report these constituents would impose an
unnecessary burden on paint manufacturers. In addition, the levels of
some constituents are controlled by the existing TC regulations.
Furthermore, as noted previously, EPA has recently proposed a NESHAP
for miscellaneous paints and coating manufacturing operations that
would regulate wastewaters, both on-site and if sent off-site for
treatment.\33\
[[Page 10108]]
Thus, we are proposing paint manufacturing waste liquids treated in
off-site treatment tanks are not subject to today's proposed listing.
---------------------------------------------------------------------------
\33\ As discussed previously, some off-site nonhazardous
wastewater treatment facilities may also be covered by the NESHAP/
MACT standards in 40 CFR part 63 (61 FR 34140, July 1, 1996), if
they are a major source of hazardous air pollutant (HAPs) emissions
defined in section 112 of the CAA amendments of 1990, and if the
wastes they receive from off-site contain one or more HAPs.
---------------------------------------------------------------------------
D. Why Are We Proposing a Contingent Management Listing for Liquid
Paint Manufacturing Wastes, and What Other Options Are We Considering?
We are considering various options for the listing for paint
manufacturing waste liquid (K180). Under the listing proposed for K180,
the wastes would not be listed if they are managed in on-site storage
and treatment tanks or containers prior to discharge to a POTW or under
a NPDES permit. (Of course, if the concentrations of the listing
constituents are below the regulatory levels, the waste would not be
hazardous in any case.) We are proposing this type of ``contingent
management'' listing because we did not find significant risk from
treatment or storage in tanks, as noted above. However, if a paint
manufacturing waste generator intends to send the waste off-site for
treatment outside of tanks (and waste constituents are not below the
listing levels), the waste would be K180 and would be subject to
storage requirements under Subtitle C. We recognize that the regulation
of the onsite storage and treatment of the waste in tanks prior to the
waste being shipped offsite may be unwarranted because our risk
analysis for tanks shows no significant risk for liquid paint
manufacturing waste. Therefore, we are soliciting comment on the option
of exempting wastes stored or treated on-site in tanks or containers
from being a hazardous waste while it is stored on-site, regardless of
what the ultimate treatment or disposal practice might be. This would
mean that the point of generation for K180 would be when the waste is
sent off-site, and that it would not be classified as K180 hazardous
waste while it is stored or treated in tanks or containers on-site
prior to shipment off-site for disposal.
The constituent levels we are proposing are based on the possible
risks from management of the liquid wastes in an off-site centralized
wastewater treatment system with an unlined surface impoundment. We did
not complete a risk assessment for possible risks for various other
known or potential management practices. Given that we found risk in
one management scenario, but did not assess risks from other major
practices, we are limiting the exemption from the listing to the
management practice that we determined posed no significant risk, i.e.,
management in tanks. Therefore, we are proposing to list the paint
manufacturing waste liquids, unless they are managed in tanks prior to
discharge under an NPDES permit or to a POTW.
As discussed in Section II.G, the 3007 Survey showed that 21 paint
manufacturers reported sending their liquid wastes to 24 off-site
wastewater treatment facilities. We contacted 9 of these 24 and found
one treatment facility that reported using a lined surface impoundment
to treat two different paint manufacturers' liquid wastes. Based on the
weighting factors used for our survey sample, we estimate these 24 off-
site wastewater treatment facilities represent about 40 facilities in
the U.S. that may accept paint liquids. While we cannot extrapolate the
information from nine wastewater treatment facilities to the overall
population, we estimate that there could be 4 to 5 treatment facilities
that use impoundments of some kind. The one facility with an
impoundment indicated the unit was lined, however there are no Federal
regulatory requirements that ensure this would be the case for other
impoundments throughout the country. Hence, it may be reasonable to
assume that some of these impoundments may be unlined for modeling
purposes. We note that surface impoundments are used to treat
wastewaters in general, and that a recent study confirmed that a
significant portion of impoundments in some industries are unlined.\34\
(However, this study focused primarily on on-site impoundments used in
specific industries, and not commercial off-site treatment facilities).
Therefore, if we assume management of liquid wastes in an unlined
impoundment is a plausible management scenario, our assessment suggests
that the risks from such management may present a significant potential
hazard to human health and the environment for some constituents of
concern.
---------------------------------------------------------------------------
\34\ Based on an initial review of data from the Study of
Industrial Non-hazardous Waste Surface Impoundments required under
the Land Disposal Program Flexibility Act. Also, in a 1995 EPA found
only 26 States had requirements for liners under State regulations:
see State Requirement for Industrial Non-Hazardous Waste Management
Facilities, U.S. Environmental Protection Agency, October 1995.
---------------------------------------------------------------------------
However, we are also seriously considering not listing paint
manufacturing waste liquids, or using a different approach for a
listing, due to the uncertainty in management practices we assumed in
our risk assessment. While we are proposing to list because of
potential risks arising from unlined surface impoundments, we are
considering the alternative of not listing this waste because this may
not be a ``plausible'' management scenario. As noted above, while the
survey data shows that management in an off-site treatment facility is
relatively common, we found only one case where a surface impoundment
was in use. We estimate that only 4 to 5 such impoundments may be
receiving any of the paint manufacturing waste liquids from the
estimated 972 paint manufacturers. Thus, management of these wastes in
surface impoundments appears to be an infrequent occurrence. The number
of unlined impoundments receiving this waste is more uncertain due to
our limited data on surface impoundments, but the probability of off-
site commercial treatment facilities treating paint manufacturing
wastes in such unlined units is likely to be even lower than the number
of facilities using impoundments.
The effectiveness of liner systems depends, in part, on how they
are designed. Composite and double liners that combine two or more
layers of liner material with leachate collection and leak detection
should minimize leakage to the subsurface during the period when the
leachate collection system is actively managed. While it is difficult
to predict the level of protection afforded by a liner system due to
the uncertainty concerning long-term performance, we believe the level
of protection could be significant for a surface impoundment, which
will contain liquid wastes only during its operating life.\35\
Therefore, our assessment of an unlined surface impoundment may
overestimate potential risks from this disposal scenario.
---------------------------------------------------------------------------
\35\ We believe there is greater uncertainty about the efficacy
of liners in providing long-term protection from releases from
landfills, because the wastes remain indefinitely. A synthetically
lined impoundment with a finite operational life of perhaps 30 to 50
years is less likely to release wastewater during the life of the
unit. During operation, leaks in the liner system would be detected
and presumably fixed; active use of an impoundment can be stopped,
drained, and liners repaired. Also, the leachate collection system
is likely to prevent a significant release during operation.
---------------------------------------------------------------------------
The risk results from modeling surface impoundments may also
overestimate risks for other reasons. As noted in Section III.E, we
used impoundment data gathered in a 1985 Industrial D Screening Survey.
We were not able to distinguish off-site vs. on-site impoundments from
these data, so we used a sample from all units in the database. Because
most impoundments
[[Page 10109]]
are part of on-site treatment processes for industrial process
wastewater, the data include a variety of types of units that may not
be realistic for the off-site commercial wastewater treatment
facilities we are attempting to model. Our database contains units with
characteristics that are unlikely for large off-site treatment
facilities, i.e., many units are relatively small (median area about
3,200 m\2\) and have low flow rates with long retention times (median
retention time about 0.5 years, 90th percentile retention of 50 years).
These characteristics mean that many of the impoundments used in the
modeling would have a fairly high fraction of paint manufacturing
waste, e.g., the 90th percentile value for fraction of paint
manufacturing waste in the unit was one. We believe that off-site
commercial treatment units are more likely to be larger and have much
shorter retention time, thereby reducing the average fraction of paint
manufacturing waste in the treatment units. While it is difficult to
gauge the importance of these characteristics in our risk assessment
results, these may lead to an overestimate of impoundment risks. We may
use this factor, in conjunction with a full review of all comments, as
an additional reason not to list paint manufacturing waste liquids.
We solicit any information on the prevalence of surface impoundment
management of paint manufacturing waste liquids, and any data related
to the use of surface impoundments, either lined or unlined. After
reviewing all comments and reconsidering all available information on
the possible risks from management of paint manufacturing waste
liquids, we may decide not to list this waste.
Assuming we decide to finalize a listing for paint manufacturing
waste liquids due to the potential for risks from surface impoundments,
we are also soliciting comments and supporting data on an alternative
listing that would exclude other practices, such as incineration and
fuel blending. We could limit the scope of the listing so that it would
clearly apply only to wastes managed in surface impoundments. Thus, the
listing could specify that it would apply only if the waste exceeded
the regulatory concentration levels, and if the waste was managed in a
surface impoundment. We may decide that such an approach is appropriate
in this case given that this was the only practice modeled that
presented unacceptable risk, and because the practice may be very
infrequent. For the paint manufacturing wastes at issue in today's
proposal, we did not find significant risks from management in
tanks.\36\
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\36\ Discharges to surface waters are controlled under the CWA
and require an NPDES permit, while discharges to a POTW are subject
to State and national pretreatment standards. Note that 40 CFR 261.4
reflects the RCRA statute and excludes ``any mixture of domestic
sewage and other wastes that passes through a sewer system to a POTW
for treatment'' (40 CFR 261.4(a)(1)(ii)), and industrial wastewater
discharges that are point source discharges subject to regulation
under Section 402 of the CWA (40 CFR 261.4(a)(2)).
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The other reported management practices of potential concern were
thermal treatment in incinerators, cement kilns, and fuel blending. As
noted previously, in past listing determinations where we have
attempted to assess risks from incineration, we found that the
potential risks from the release of constituents through incineration
would be at least several orders of magnitude below potential air risks
from releases from tanks or impoundments (see listing determination for
solvent wastes at 63 FR 64371, November 19, 1998). Although metal
constituents would not be destroyed in thermal treatment, we expect the
metal content of nonhazardous paint manufacturing waste liquids sent to
incineration to be low; this is consistent with the 3007 Survey data,
which show no nonhazardous paint manufacturing waste liquids with
significant metal content. Limiting the listing to wastes only managed
in impoundments would reduce the overall burden of the listing, so that
it would apply only to the practice of most potential concern, i.e.,
surface impoundments.
E. Potential for Formation of Non-Aqueous Phase Liquids in Paint
Manufacturing Wastes
We considered the possibility that some constituents in paint
manufacturing wastes might form distinct nonaqueous phase liquids
(NAPLs). NAPLs can be an issue, because once released to the subsurface
a number of difficult problems may occur. Such problems include the
creation of a long-term NAPL source in the subsurface and facilitated
transport of contaminants that have an affinity for the NAPL fraction.
The formation of NAPLs is strongly dependent on the specific wastes in
question and the management practice, and it is difficult to predict
when NAPLs might be important. However, many of the organic chemicals
we evaluated for this listing are highly water soluble and in many
cases volatile, thus most have little potential for NAPL formation. EPA
has used a general approach in the Hazardous Waste Characteristics
Scoping Study to identify which chemicals have some potential to form
NAPLs based on water solubility and other parameters.\37\ NAPL-forming
chemicals generally have relatively low water solubilities (less than
5,000 mg/L) and are liquids at ambient temperature. Applying these
criteria, the only non-TC constituents of concern that may potentially
form NAPLs would be the phthalates and the aromatic hydrocarbons
(ethylbenzene, styrene, toluene, and xylenes). Any NAPL-forming
chemicals that are regulated under the TC (i.e., the slightly soluble
chemicals benzene and tetrachloroethylene) are unlikely to form NAPLs
in wastes, because the TC levels are well below their water solubility.
Thus, wastes with TC constituents high enough to form NAPLs would be
regulated as hazardous, and would not be land disposed until treated.
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\37\ U.S. Environmental Protection Agency, Office of Solid Waste
and Emergency Response, Hazardous Waste Characteristic Scoping
Study, November 1996, and U.S. Environmental Protection Agency,
Office of Solid Waste and Emergency Response, Evaluation of the
Likelihood of DNAPL Presence at NPL Sites, EPA 540-R-93-073,
September 1993.
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We believe that paint manufacturing wastes with the high organic
content needed to form NAPLs are unlikely to be land disposed for
several reasons. First, high organic wastes are typically sent for
thermal treatment or recycling. For example, see the final listing
determination for solvents (63 FR 64372, November 19, 1998); we found
that solvent wastes with high organic content are usually thermally
treated, and that wastes sent to landfills contained negligible amounts
of solvent (63 FR 64384). Also, many landfills are unlikely to accept
wastes with free liquids, and in fact such a practice is restricted
under Federal regulations for municipal solid waste landfills
(Sec. 258.28) and Subtitle C landfills (Sec. 264.314). Similar
restrictions, while not federally mandated, are in place in most States
for off-site nonmunicipal solid waste landfills.\38\
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\38\ U.S. Environmental Protection Agency, Office of Solid
Waste, State Requirements for Industrial Non-Hazardous Waste
Management Facilities, October 1995.
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We believe that any paint manufacturing waste liquids that may be
placed in impoundments or tanks at offsite wastewater treatment
facilities are unlikely to contain significant NAPLs. The nonhazardous
paint manufacturing waste liquids are nearly all reported to be from
aqueous washing of equipment, with only one facility reporting
generating a nonhazardous liquid from solvent cleaning; this facility
sent this waste to a fuel blender.
[[Page 10110]]
All other waste solvents were coded and managed as hazardous waste.
This is not surprising, given that many solvents used for cleaning
equipment would yield wastes that are listed as hazardous (F001 through
F005), or exhibit a characteristic, such as ignitability.
The nonhazardous water cleaning liquids are mixed with other
wastewaters when treated in offsite centralized wastewater treatment
systems, making significant NAPLs less likely. As noted above in
Section IV.A, existing and proposed regulations under the CAA would
also tend to keep the organic content of wastewaters low for any
chemical designated a hazardous air pollutant, or HAP. Nearly all
constituents of potential concern we identified for paint manufacturing
wastes are HAPs under the CAA. We believe that these rules make it
unlikely that NAPLs would form in offsite wastewater surface
impoundments.
The information in the 3007 Survey suggests that wastes with liquid
or free solvents are not disposed in landfills. The waste data we
collected from the 3007 Survey indicates that few of the nonhazardous
paint manufacturing wastes of concern have the high organic content
necessary to form a separate NAPL phase. Of the nearly 200 nonhazardous
wastes reported (125 solids, 74 liquids), only 15 were reported to have
levels of any organic constituent above relatively low levels (1%). In
most of these 15 cases, the organic constituents included levels of
associated polymers (polymers of acrylonitrile, styrene, and vinyl
acetate). The few nonhazardous wastes with significant concentrations
of a constituent that might form a NAPL (3 wastes reported to contain
2% or 6% butyl benzyl phthalate) went to incineration (one waste with
10% xylene went to unspecified offsite treatment). The remaining wastes
with significant organic content contained ethylene glycol, which is
highly unlikely to form NAPLs given its extreme solubility in water. In
any case, only one waste with organic content above 1% was reported to
go to a landfill (an off-specification paint manufacturing waste with
2.5% ethylene glycol). We recognize that the information for
constituents in the 3007 Survey is limited, however, the data in hand
show that generators do not appear to be sending paint manufacturing
waste with high organic content to land disposal. Even in the event
some generators were sending some wastes with higher potential NAPL-
forming chemicals to land-based units, the volumes would be relatively
small. This makes it unlikely that organic levels in these units would
be sufficient to generate a NAPL phase that would impact releases to
groundwater.
As noted previously in Section IV.A, EPA is planning to propose a
MACT standard to address potential releases of volatile HAPs from paint
manufacturing facilities. The proposed MACT would place limits on HAPs
in wastewaters and keep organic levels in paint manufacturing waste
relatively low.
As another check on the potential for NAPL formation in paint
manufacturing wastes, we examined the Survey data for discarded off-
specification paint. Our survey data indicated that disposal of off-
spec products in landfills was fairly infrequent (13 facilities
reported a total of 941 metric tons in 1998). From follow-up telephone
calls to these generators, the facilities almost uniformly indicated
that the off-specification material was not in liquid form; the wastes
were in solid resins, hard cured by drying, or otherwise solidified
prior to disposal.
F. Scope of the Listings and the Effect on Treatment Residuals
Today's proposal would result in two new hazardous waste listings
that differ from previously promulgated listed hazardous wastes in that
they include constituent-specific concentrations to define the scope of
the listings. The primary purpose of these ``concentration-based
listings'' is to establish levels at the point of generation of a
waste, above which that waste is considered to be a listed hazardous
waste (i.e., ``entrance'' levels). Wastes that are generated below
these levels would not be subject to these listings.
We are also proposing to use the listing concentrations as ``exit''
levels for residues from paint manufacturing waste solids (K179).
Residuals from the treatment, storage, or disposal of listed hazardous
wastes are usually classified as hazardous wastes based on the
``derived-from'' rule (see 40 CFR 261.3(c)(2)(i)).\39\ The use of the
listing concentrations as exit levels for treatment residues would
terminate the applicability of the derived-from rule and, therefore,
the treatment residues would no longer be considered a listed hazardous
waste. We are specifically proposing to add language to the standards
in 40 CFR 261.3 to describe this self-implementing process for paint
manufacturing waste solids (K179). For reasons discussed below, we are
proposing that generators cannot use the listing levels for paint
manufacturing waste liquids (K180) as exit levels, even if the waste
falls below those levels through treatment. In the following discussion
we also clarify further the status of liquids derived from paint
manufacturing waste solids and vice-versa, and address mixtures or
treatment residues that occur away from the paint manufacturing
facility, such as at an off-site treatment facility.
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\39\ Also, the ``mixture'' rule (see 40 CFR 261.3(a)(2)(iii) and
(iv)) provides that, with certain limited exceptions, any mixture of
a listed hazardous waste and a solid waste is itself a RCRA
hazardous waste. We are not proposing any changes to the mixture
rule in today's action.
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We envision that the proposed listing of the paint manufacturing
waste solids (K179) would function similarly to a hazardous waste
characteristic such as toxicity, except that the concentration levels
would be the basis for deciding a waste is hazardous only when applied
to the solids as generated or managed at a paint manufacturing
facility. Thus, a waste would become hazardous K179 only if it meets or
exceeds the listing levels at the paint manufacturing facility.
Structuring the listing for paint manufacturing waste solids in this
way avoids implications for solids generated off-site from a
nonhazardous waste that in part, or in whole, originated from a paint
manufacturing facility. For example, we avoid small quantities of
nonhazardous paint manufacturing waste liquids treated at an off-site
commercial wastewater treatment facility subjecting any liquid or solid
derived from them at an offsite treatment facility to evaluation
against the levels proposed today for paint manufacturing wastes.\40\
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\40\ Note that a paint manufacturing waste solid could be
nonhazardous when generated, but become hazardous later if
management on-site led to the waste becoming more concentrated and
exceeding the listing levels. If this occurs at the paint
manufacturing facility, it would become a listed K179 waste.
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We are proposing, however, that the paint manufacturing waste
solids that are hazardous K179 may be treated to generate nonhazardous
waste, if the treatment results in constituent concentrations that are
below the listing levels in K179. Note that land disposal restrictions
would still apply, as they do to ``decharacterized'' waste that was
hazardous only due to a hazardous waste characteristic, until the waste
meets the LDR treatment requirements (see Section VI of today's notice
for the proposed standards). Thus, if treatment of K179 yields
constituent levels that are below the listing levels and meet the
appropriate LDR standards, the waste may be disposed as a nonhazardous
waste (e.g., in a Subtitle D landfill). We are specifically proposing
to add language to the standards in 40 CFR 261.3 to exempt solids that
previously
[[Page 10111]]
met the K179 listing, if the constituent levels are below the listing
levels. We request comment as to whether the derived-from rule should
apply to the K179 paint manufacturing wastes solids beyond the paint
manufacturing site as they would in a traditional listing. However, we
believe that our evaluation of the risks of disposal of solid K179
would apply equally well to solids that have been treated.
The proposed listing of paint manufacturing waste liquids (K180)
operates like a characteristic only in the sense that if a paint
manufacturing waste is below the listing level at the point of
generation, it is not covered by this listing. However, it would act as
a traditional listing if a paint manufacturing liquid waste generated
at a paint manufacturing facility meets or exceeds the listing levels,
in that liquids derived from K180 remain subject to the listing even if
they fall below those levels through dilution or treatment. We are
proposing that liquid residuals from K180 wastes would remain
hazardous, because the surface impoundment scenario we used to set the
listing concentrations for K180 assumed that the liquid paint wastes
are mixed with other wastewaters in an off-site treatment facility. The
listing levels we set for K180 are for the waste prior to any mixing
and would necessarily be higher than the levels of the constituents
that may exist in the off-site impoundment. We believe that the listing
levels for K180 would not be appropriate for use in exiting the RCRA
hazardous waste regulatory program, because they do not correspond to
risk-based levels for the diluted waste in the impoundment.\41\
Therefore, we are proposing that any liquid wastes derived from K180
would remain listed as K180 (unless the waste is excluded under the
petition process set out in Secs. 261.20 and 261.22, typically known as
``delisting'').
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\41\ Furthermore, wastes that are otherwise prohibited from land
disposal may be treated in surface impoundments or series of
impoundments that meet certain conditions (see section 268.4).
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We are proposing that the scope of the listings reflect the
practical situations that arise at the site of paint manufacturing if
derived-from wastes are in a different form than the original paint
waste, i.e., if liquid wastes are derived from K179, and if waste
solids are derived from K180. In such cases, we believe that is more
appropriate to evaluate these on-site derived-from wastes against the
listing concentrations that reflect the corresponding waste form.
Solids generated from K180 at the site of paint manufacturing would no
longer be K180, but would be subject to classification as K179, if the
waste meet or exceed the listing levels for K179. Under this approach,
solids generated from K180 on-site that are below the listing levels
for K179 would not be a hazardous paint waste. Similarly, a liquid
waste derived from K179 at the site of paint manufacturing would be
evaluated against the K180 listing conditions; if such a liquid is
either managed exclusively in tanks or containers, or if the
constituents in the liquid are below the listing levels for K180, the
K179-derived liquid would not be hazardous paint waste. We have
included text in the listing descriptions for K179 and K180 to
establish these changes in waste codes for on-site derived-from wastes.
We are not proposing that the above change in waste codes would
apply to waste residuals generated off-site. We believe that changes in
waste codes would be confusing for off-site treatment facilities and
may be difficult to track and enforce. Furthermore, K179 or K180 wastes
that are sent off-site for treatment would likely be treated at a
facility that accepts and treats a wide variety of hazardous wastes,
and any derived-from wastes generated from treatment of K179 or K180
would likely carry multiple hazardous waste codes. Therefore, we are
proposing to allow the mixture-derived from rules to operate normally
off-site, except for the exemption for treated K179 noted previously.
This approach still allows a treatment facility to use the exemption to
the derived-from rule we are proposing for waste solids (K179); the
treatment facility would have to treat only for the K179 hazardous
constituents of concern (provided no new characteristics are imparted
by the treatment process).
Finally, we stress that solids and liquids derived off-site from
nonhazardous paint manufacturing liquids are not listed paint
manufacturing wastes (i.e., not K179 or K180). Such wastes are not
paint manufacturing wastes, in that the waste management facility is
not directly involved in the manufacture of paint products. Therefore,
these wastes would not be subject to the listing criteria for K179 or
K180.
G. Relationships of the Proposed Listings to the TC
Fifteen constituents that we assessed for paint manufacturing waste
are also constituents covered by the broadly-applicable Toxicity
Characteristic (TC). We modeled these constituents, along with the
constituents not covered by the TC, to see if for any reason the
modeling approach would indicate a significant hazard would be posed
that is not already addressed by the TC. This might have occurred, for
example, if the windblown dust pathway had produced significantly lower
concentrations. However, we found that, with one exception, the
concentrations of concern predicted in the paint-waste modeling were
above the levels already regulated by the TC.
For the fourteen constituents for which the paint modeling yielded
concentrations higher than TC levels, we are not setting levels in this
listing, and the TC will continue to apply. We are proposing to retain
the more restrictive TC levels for these constituents to protect human
health and the environment. The specific levels calculated for paint
manufacturing waste for this proposal represent amounts of constituents
that can be safely disposed for the relatively small volumes of paint
manufacturing waste solids and liquids subject to today's proposed
listing. The TC levels, in contrast, broadly address all wastes in the
country subject to RCRA Subtitle C. They were designed to protect human
health and the environment from the possibility that many waste streams
from multiple generators could be disposed of in a single landfill.
Consequently, our TC risk assessments reflect much higher waste volumes
arising from a broad spectrum of industries and sources. If we analyzed
by itself any individual, small-volume waste stream subject to the TC,
we might find that it did not pose risks at TC levels. However, a set
of smaller waste streams from multiple sources could pose risks if
disposed together with other wastes. Consequently, we believe we need
to retain the broad, multiple-waste TC approach.\42\
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\42\ This is consistent with current EPA regulations regarding
``delisting petitions'' under 40 CFR 260.22(c) and (d). If modeling
indicates the waste does not pose a significant hazard, EPA exempts
it from the hazardous waste listing. However, as required under the
regulations, we do not exempt wastes that exhibit a hazardous waste
characteristic.
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For the remaining constituent, pentachlorophenol, the paint listing
modeling results (at the 90th percentile probabilistic level) showed a
protective leachable concentration of 66 mg/L. This is slightly lower
than the existing TC level (100 mg/L). Upon review of 3007 survey data
on prevalence, however, we found that this constituent is not currently
used in paint production and it is not likely to be found in paint
manufacturing wastes. While pentachlorophenol has apparently been used
historically as a biocide in paint formulations, most
[[Page 10112]]
pesticide uses of this chemical have been halted.\43\ In addition,
despite the fact that this is a TC constituent, this chemical was not
reported in any of the wastes in the 3007 survey data. Given these
facts we see no reason to include pentachlorophenol as a listing
constituent for paint manufacturing wastes. The TC, of course, would
continue to apply to any paint manufacturing waste containing
pentachlorophenol, and wastes exceeding the TC level would be regulated
as hazardous.
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\43\ See the cancellation for non-wood uses at 52 FR 2282,
January 21, 1987.
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H. What Is the Status of Landfill Leachate From Previously Disposed
Wastes?
Leachate derived from the treatment, storage, or disposal of listed
hazardous wastes is classified as a hazardous waste by virtue of the
``derived-from'' rule in 40 CFR 261.3(c)(2). The Agency has been clear
in the past that hazardous waste listings apply to wastes disposed of
prior to the effective date of a listing, even if the landfill ceases
disposal of the waste when the waste becomes hazardous. (See 53 FR
31147, August 17, 1988). We also have a well-established interpretation
that listings apply to leachate derived from the disposal of listed
hazardous wastes, including leachate derived from wastes meeting the
listing descriptions that were disposed before the effective date of a
listing. We are not reopening nor taking comment on any of these issues
with this proposed rulemaking.
Of course, as set out in detail in the August 1988 notice, this
does not mean that landfills holding wastes that are listed now as
hazardous become subject to Subtitle C regulation. However, previously
disposed wastes now meeting a listing description, including residues
such as leachate that are derived from such wastes, and that are
managed actively do become subject to Subtitle C regulation. See 53 FR
at 31149, August 17, 1988. In many, indeed most, circumstances, active
management of leachate would be exempt from Subtitle C regulation
because the usual pattern of management is discharged either to POTWs
via the sewer system, where leachate mixes with domestic sewage and is
excluded from RCRA jurisdiction (see RCRA section 1004(27) and 40 CFR
261.4(a)(1)), or to navigable waters, also excluded from RCRA
jurisdiction (see RCRA section 1004(27) and 40 CFR 261.4(a)(2)). In
addition, management of leachate in wastewater treatment tanks prior to
discharge under the CWA is exempt from RCRA regulation (40 CFR
264.1(g)(6)).
It is possible that waste solids within the proposed scope of K179
may have been disposed in landfills. Because we are proposing that
liquids derived from the offsite management of K179 would continue to
carry the K179 waste code, leachate from a landfill that accepted paint
manufacturing waste solids might be classified as K179. While we do not
believe that it is likely that liquid K180 wastes would have been
disposed in landfills in significant quantities, a landfill may have
accepted a derived-from K180 solid (as a result of offsite treatment).
However, the proposed listings for the two paint manufacturing wastes
are concentration-based listings, and it would be difficult to know
whether the previously disposed wastes that meet the narrative
description of K179 did in fact have constituent concentrations that
would be at or above the K179 listing levels. We don't anticipate that
records documenting the concentrations of proposed constituents of
concern for these wastes exist for previously disposed wastes.
Therefore, absent a finding that the disposed wastes would have met the
listing being proposed today, it is unlikely that the previously
disposed wastes would be classified as K179, and thus unlikely that
landfill leachate and gas condensate derived from these wastes that are
actively managed would be K179.
However, if actively managed landfill leachate and gas condensate
derived from the newly-listed wastes proposed for listing in today's
notice could be classified as K179, we would be concerned about the
potential disruption in current leachate management that could occur,
and the possibility of redundant regulation. This issue was raised to
the Agency in the context of the petroleum refinery waste listings (see
63 FR 42173, August 6, 1998). A commenter expressed concern that,
because some of the commenter's nonhazardous waste landfills received
newly-listed petroleum wastes prior to the effective date of the
listing decision, the leachate that is collected and managed from these
landfills would be classified as hazardous. The commenter argued that
this could lead to vastly increased treatment and disposal costs
without necessarily any environmental benefit. After examining and
seeking comment on this issue, we published a final rule that
temporarily defers regulation of landfill leachate and gas condensate
derived from certain listed petroleum refining wastes (K169-K172) that
were disposed before, but not after, the new listings became effective,
provided certain conditions are met. See 64 FR 6806, February 11, 1999.
We proposed listing determinations for wastes from the dye and pigment
industries (64 FR 40192, July 23, 1999) and from the inorganic chemical
manufacturing industries (65 FR 55684, September 14, 2000) that propose
deferrals for similar wastes derived from landfills. We also
promulgated a listing determination for the chlorinated aliphatics
industry (65 FR 67068, November 8, 2000) that retains the deferral.
At the time this issue was brought to the Agency's attention in the
context of the petroleum refinery waste listings, EPA's Office of Water
had recently proposed national effluent limitations guidelines and
pretreatment standards for wastewater discharges--most notably,
leachate--from certain types of landfills. See 63 FR 6426, February 6,
1998. In support of this proposal, EPA conducted a study of the volume
and chemical composition of wastewaters generated by both subtitle C
(hazardous waste) and Subtitle D (nonhazardous waste) landfills,
including treatment technologies and management practices currently in
use. Most pertinent to finalizing the temporary deferral for the
petroleum refining wastes, EPA did not propose (or subsequently
finalize) pretreatment standards for subtitle D landfill wastewaters
sent to POTWs because the Agency's information indicated that such
standards were not required (see 65 FR 3008, January 19, 2000).
The conditions included in the temporary deferral we published on
February 11, 1999 are that the leachate is subject to regulation under
the Clean Water Act, and the leachate cannot be stored in surface
impoundments after a period of two years (February 13, 2001). See 40
CFR 261.4(b)(15). We believe that it was appropriate to temporarily
defer the application of the new waste codes to such leachate in order
to avoid disruption of ongoing leachate management activities while the
Agency decides if any further integration is needed of the RCRA and CWA
regulations consistent with RCRA section 1006(b)(1). We believe that it
is still appropriate to defer regulation and avoid leachate management
activities, and to permit the Agency to decide whether any further
integration of the two programs is needed. As such, we would be
concerned about forcing pretreatment of leachate even though
pretreatment is neither required by the CWA, nor needed. Therefore, we
are proposing to temporarily defer the regulation of landfill leachate
and gas condensate derived from management of K179 and K180 wastes that
we are
[[Page 10113]]
proposing for listing in today's rule, with the same conditions as
described in 40 CFR 261.4(b)(15) for petroleum wastes. We request
comment on this proposed conditional deferral.
V. Proposed Generator Requirements for Implementation of
Concentration-Based Listings
We are proposing that these concentration-based listings be self-
implementing. This means that you (the waste generator) would be
responsible for determining whether or not your wastes are K179 or K180
listed hazardous wastes at the point of generation based on the
proposed procedures we describe below.\44\ We are proposing a two-
tiered implementation approach for the concentration-based listings,
based on waste form (liquids or solids) and total annual quantity of
the paint manufacturing wastes generated at each paint production
facility, that you could use to determine whether your wastes are
nonhazardous. Before using the proposed two-tiered approach, you would
determine if any of your paint manufacturing waste solids or paint
manufacturing waste liquids could contain any of the constituents of
concern identified for these types of wastes (see Tables IV.A-1 and
IV.A-2). We are proposing that you could use knowledge of your wastes
(e.g., knowledge of the constituents in your wastes based on existing
sampling and analysis data and/or information about raw materials used,
production processes used, and degradation products formed) to make
this initial determination regardless of the quantity of waste you
generate. If any portion of your wastes at the point of generation will
not contain any of the constituents of concern identified for your
specific type of wastes, you would not have to use the two-tiered
approach to determine whether those wastes are nonhazardous (i.e., are
not K179 or K180 listed wastes). Paint manufacturing wastes described
in the K179 or K180 listings, but which do not contain any of the
constituents of concern for K179 or K180, would not be K179 or K180
hazardous wastes at the point of generation. You should note, however,
that absence of the constituents of concern in some portion of your
wastes would not relieve you, the generator, from hazardous waste
determination requirements for all other wastes that do contain
constituents of concern.
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\44\ Due to the uncertainties in our assessment of the
management of paint manufacturing waste liquids in surface
impoundments, we are considering an alternative proposal not to list
paint manufacturing waste liquids. We describe this alternative
elsewhere in this notice (see Section IV.D). The following
discussion describes the approach we are proposing for paint
manufacturing waste liquids if K180 is listed.
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If your paint manufacturing wastes contain one or more constituents
of concern, then you would either use the two-tiered approach to
determine whether they are nonhazardous or handle them as hazardous.
Under this proposed approach, if you generate or expect to generate 40
metric tons or less of paint manufacturing waste solids or 100 metric
tons or less of paint manufacturing waste liquids annually, then you
would have the option of testing the wastes or using knowledge of the
wastes to determine whether they are nonhazardous. However, if you
generate or expect to generate over 40 metric tons of paint
manufacturing waste solids or over 100 metric tons of paint
manufacturing waste liquids, then you would be required to test the
wastes annually to determine whether they are nonhazardous. Our reasons
for proposing a two-tiered approach and requiring annual testing of
larger quantity wastes are discussed in Section V.C. The exception to
the annual testing requirement to determine whether wastes are
nonhazardous, regardless of annual waste quantities generated, would be
for paint manufacturing waste liquids that are stored or treated
exclusively in tanks or containers and then discharged to a POTW or
under a NPDES permit.
We are proposing the constituents of concern for the two types of
wastes (solids and liquids) from paint production that are listed in
Tables IV.A-1 and IV.A-2. We are also proposing the listing (hazardous
concentration) level for each of these constituents that are in the
same tables. We are proposing that you use this information, in
conjunction with testing or knowledge of constituent levels in your
wastes, to determine whether or not the wastes are hazardous.
Unless you make a determination that your wastes are nonhazardous
for K179 or K180, using either knowledge that the wastes do not contain
any of the constituents of concern or the specified procedures
described in section C below, then we are proposing that your wastes
would be hazardous and you would be subject to the existing
requirements under RCRA for persons who generate hazardous waste. Thus,
if you are not already a hazardous waste generator, you would have to
notify the EPA, according to section 3010 of RCRA, that you generate a
hazardous waste. You would also be subject to all applicable
requirements for hazardous waste generators in 40 CFR Part 262.
If you determine that your paint manufacturing waste solids or
liquids are nonhazardous, we are proposing to require, under the
authority of sections 2002 and 3007 of RCRA, that you keep certain
records (see Section E below) of your wastes at the generating site
(on-site). Following the initial nonhazardous determination, you would
be obligated to ensure that your wastes continue to meet all of the
proposed conditions and requirements for the wastes to be deemed
nonhazardous. Accordingly, you should also note that regardless of any
type of nonhazardous determination that you make for your wastes, the
wastes would be hazardous if we test and find that they actually have
constituents of concern at or above the listing levels.
A. Would I Have to Determine Whether or Not My Wastes Are Hazardous?
Yes, we are proposing that you must determine whether or not your
wastes are hazardous K179 or K180 wastes. This hazardous waste listing
determination could be made in either of two ways. First, you could
assume that your wastes are hazardous at the point of generation. If
you do this, then you could forego the requirement for testing or using
knowledge of the wastes to make a hazardous waste determination. In
such a case, your wastes would be subject to all applicable RCRA
Subtitle C hazardous waste requirements, including LDR requirements,
either as of effective date of the final rule or as of initial
generation of the wastes. Second, if you want the opportunity to
determine that your wastes are nonhazardous at the point of generation
(and therefore not subject to Subtitle C hazardous waste requirements),
we are proposing that you must either test the wastes or use knowledge
of constituent concentrations in the wastes using the procedures
described in Section C below. The only exception to using procedures in
Section C to determine that your wastes are nonhazardous would be if
you generate paint manufacturing waste liquids that will be stored or
treated exclusively in tanks or containers.
B. How Would I Manage My Wastes During The Period Between the Effective
Date of The Final Rule and Initial Hazardous Waste Determination for My
Wastes?
If you generate wastes that are described in either K179 or K180,
we are proposing that you could not dispose of your wastes as
nonhazardous until you complete an initial determination which shows
that your wastes are nonhazardous except for
[[Page 10114]]
waste liquids managed exclusively in tanks or containers prior to
discharge to a POTW or under a NPDES permit. In the interim (from the
time you generate the wastes to the time you make a determination on
your wastes), you would be responsible for storing your wastes
properly. If your wastes are determined to be hazardous and you are not
complying with the Subtitle C storage requirements during the interim
period, then you would be subject to an enforcement action for improper
storage.
C. What Procedures Would I Follow to Determine If My Wastes Are
Nonhazardous?
We are proposing that you use the following procedures annually to
determine if your wastes, which contain one or more constituents of
concern, are nonhazardous at the point of generation:
1. You must use the previous year's waste generation data
(previous 12 consecutive months) or, if this data is not available,
estimate the total annual quantities of paint manufacturing waste
solids and paint manufacturing waste liquids that you expect to
generate over the next 12 consecutive months based on current
knowledge. You must combine the quantities of hazardous wastes
(characteristic and otherwise listed) and nonhazardous wastes that
meet the listing description for K179 or K180 to separately
determine the total annual waste quantities for both the paint
manufacturing waste solids and paint manufacturing waste liquids.
Then, you must record the total annual quantities of paint
manufacturing waste solids and paint manufacturing waste liquids
that you expect to generate. If you initially estimate that your
waste generation would fall under the low volume tier and, at any
time within the 12 month period, the actual quantities of wastes you
generate fall within the upper volume tier, from that point, you
would be subject to the upper tier waste analysis requirements (see
step 2 below). If you have not already tested your wastes, you must
test your wastes. We are proposing that a new 12 month period for
hazardous waste determination would start when you actually exceed
the lower volume tier limit.
2. You must use the recorded total annual quantities of paint
manufacturing waste solids and paint manufacturing waste liquids
generated by your facility to determine the appropriate annual waste
analysis requirement for your wastes in accordance with the
following tables:
Table V.C-1.--Tiered Waste Analysis Requirements for Solids
------------------------------------------------------------------------
Total annual quantity of hazardous and
nonhazardous paint manufacturing waste Annual waste analysis
solids requirement
------------------------------------------------------------------------
40 metric tons and less................ Test Wastes or Use knowledge of
Wastes.
Over 40 metric tons.................... Test Wastes.
------------------------------------------------------------------------
Table V.C-2.--Tiered Waste Analysis Requirements for Liquids
------------------------------------------------------------------------
Total annual quantity of hazardous and
nonhazardous paint manufacturing waste Annual waste analysis
liquids requirement \a\
------------------------------------------------------------------------
100 metric tons and less............... Test Wastes or Use knowledge of
Wastes.
Over 100 metric tons................... Test Wastes.
------------------------------------------------------------------------
\a\ This requirement does not apply if the liquid wastes are stored or
treated exclusively in tanks or containers and then sent to POTW or
discharged under a NPDES permit.
We are proposing to establish the volume cut-offs in the above
tables based on the Sec. 3007 survey data on the annual quantities of
solid and liquid wastes generated by paint production facilities. We
used these data to develop the distributions for total hazardous and
nonhazardous solid and total hazardous and nonhazardous liquid waste
quantities generated across the sampled population of paint production
facilities (see docket for Document on Distributions of Paint
Production Wastes Generated). It was evident from these distributions
that a relatively large percentage of the total hazardous and
nonhazardous paint manufacturing wastes are generated by a relatively
small percentage of the paint production facilities. For both paint
manufacturing waste solids and liquids, approximately 90 percent of the
total hazardous and nonhazardous wastes are generated by fewer than 20
percent of the paint production facilities. Based on this observation
and in order to minimize the burden on small generators, we decided to
propose this two-tiered implementation approach for the concentration-
based listings. The tiered approach will allow small generators the
option of testing or using knowledge of their wastes to determine
whether or not their wastes are hazardous.
The annual quantity cut-off for wastes above which testing is
required (40 metric tons for waste solids and 100 metric tons for waste
liquids) is intended to ensure that the largest quantities of wastes
generated by paint production facilities are tested and, at the same
time, to minimize the burden on small generators. Using the cut-off
quantities should result in approximately 90 percent of the total
hazardous and nonhazardous paint manufacturing waste solids and paint
manufacturing waste liquids being tested annually. Using the cut-off
quantities also means that fewer than 20 percent of the facilities
would be required to test their wastes annually, and more than 80
percent of the facilities would have the option of using knowledge. We
believe that larger quantities of wastes have the potential for posing
greater environmental risk than smaller quantities of wastes if a
nonhazardous determination based on knowledge turns out to be
inaccurate. Therefore, we believe it is reasonable to require larger
quantity waste generators to test their wastes annually to make a
determination, while smaller quantity waste generators are given the
option to either test their wastes or use knowledge of their wastes
annually to make a determination. We request comment on the
appropriateness of giving smaller quantity waste generators the option
of using knowledge of their wastes annually. We will consider requiring
smaller quantity waste generators to test their wastes annually, like
the larger quantity waste generators, if significant and defensible
arguments are presented by commenters to support these requirements as
necessary and appropriate.
We also request comment on an alternative to the two-tiered
implementation approach discussed above for implementing the
concentration-based listings proposed in today's rule. We could adopt a
more streamlined approach for waste generators to use in implementing
the
[[Page 10115]]
concentration-based listings for these wastes. The streamlined
implementation approach would allow you to rely on process knowledge or
testing (i.e., lower volume tier requirements) regardless of the volume
of waste generated. If the wastes contain any constituent of concern at
or above the final risk-based listing levels, the waste would be
subject to Subtitle C requirements. The streamlined implementation
approach would be similar to the existing program for determining
whether a waste exhibits a hazardous characteristic. Although we prefer
the two-tiered approach being proposed in today's rule, we will give
careful consideration to any arguments presented or relevant waste
analysis data submitted in response to today's proposal (e.g., data
showing that only a small portion of the waste streams in the industry
exceed the listing levels) in order to decide whether a more
streamlined approach is warranted.
1. Testing Wastes
If the total annual quantity of your paint manufacturing waste
solids or paint manufacturing waste liquids which meet the listing
description of K179 or K180 falls into the tier where testing is
required (and you have decided not to assume that your wastes are
hazardous at the point of generation), we are proposing that you must
test your wastes to determine whether they are nonhazardous. (Even if
testing is required to determine that your wastes are nonhazardous, you
could still use knowledge of your wastes to document that a constituent
(or constituents) could not be present in your wastes and not test for
that constituent (or constituents)). However, knowledge of the wastes
could not be used to determine the level of constituent in your wastes.
For those wastes that you must test, we are proposing that you use
the following procedures:
(i) Develop a waste sampling and analysis plan (if you do not
already have one that is appropriate) to collect and analyze samples
that are representative of your wastes. We discuss the waste
sampling and analysis plan later in this section.
(ii) From the list of constituents of concern for paint
manufacturing waste solids or paint manufacturing waste liquids,
select the constituents that are reasonably expected to be present
in your wastes based on your knowledge of the wastes (e.g.,
knowledge of the constituents in your wastes based on existing
sampling and analysis data and/or information about raw materials
used, production processes used, and degradation products formed).
(iii) Collect an appropriate number of samples that are
representative of your wastes and analyze each for the constituents
of concern selected in step (ii).
(iv) Compare the sampling and analysis results for the
constituents of concern in your wastes to the listing levels
established for these constituents to determine if your wastes are
nonhazardous.
(v) After completing annual testing requirements for your
wastes, if all samples taken during any three consecutive years are
determined to be nonhazardous, then the annual testing requirements
for your wastes are suspended.
(vi) After suspension of the annual testing requirements for
your wastes, if paint manufacturing, formulation, or waste treatment
processes are significantly altered (i.e., if it could result in
significantly higher levels of the constituents of concern for K179
or K180), then the annual testing requirements for your wastes are
reinstituted. In order to again suspend the annual testing
requirements for your wastes, the requirement under step (v) above
has to be met.
a. Waste Sampling and Analysis Plan. Whenever you are required to
test, we are proposing that you must develop a waste sampling and
analysis plan prior to testing your wastes. In developing a sampling
and analysis plan, you would have to consider any expected fluctuations
in concentrations of constituents of concern over time. The sample
design should be described in the waste analysis plan. The sample
design and the sensitivity of the analytical methods used should be
sufficient to determine whether the levels of the constituents of
concern in the wastes are above or below the listing concentrations for
these constituents. We do not propose to specify a particular number of
samples that you would need to collect annually to obtain
representative data for your wastes. The number of samples required to
determine that the concentrations of constituents of concern in your
wastes are below the listing levels for these constituents would depend
on how close the actual concentrations were to the listing
concentrations and on the variability of the wastes you generated
during the course of the year.
As stated in step (ii) of the procedures specified above, you would
have to test for the constituents of concern that are reasonably
expected to be present in your wastes. Also, as discussed previously,
you might use knowledge of the wastes to document that a constituent
(or constituents) could not be present in your wastes. If you determine
that a constituent (or constituents) could not be present in your
wastes, then you would not need to test for it. However, if you
determine that your wastes are nonhazardous, then you would be
responsible for ensuring that your wastes do not have any constituents
of concern at or above the listing levels.
We are not proposing whether you must use grab or composite
sampling to obtain samples that are representative of your wastes.
However, we are proposing that, following a nonhazardous determination
for your wastes, enforcement by EPA or an authorized State would be
based on grab samples. It would be your responsibility to ensure that
your sampling and analysis is unbiased, precise, and representative of
your wastes. We are not proposing to require the use of SW-846 methods
to comply with these requirements. We are proposing to allow the use of
either SW-846 methods or alternative methods, so long as you can
demonstrate that the selected methods have the appropriate sensitivity,
bias, and precision to determine the presence or absence of the
constituents of concern at or below the listing concentrations. You
would be required to document the: (1) Detailed standard operating
procedures (SOPs) for the sampling and analysis protocols that you
used; (2) sensitivity and bias of the measurement process; (3)
precision of the analytical results for each batch of waste (or
``super'' batch) tested; and (4) analytical results.
We would consider the analytical results adequate to demonstrate
that concentrations for the constituents of concern in your wastes are
below the listing concentrations for these constituents if: (1) You
determined the concentrations without dilution of the wastes (i.e., no
waste or other material were added to your wastes, after the point of
generation, which did not meet the listing description of K179 or K180)
and (2) you conducted an analysis in which the constituents of concern
spiked at their listing levels indicates that the constituents of
concern are present at those levels within analytical method
performance limits (e.g., sensitivity, bias, and precision). To
determine the performance limits for a method, we recommend following
quality control (QC) guidance provided in Chapters One and Two of SW-
846.
Following sampling and analysis, if none of your waste samples
contain any of the constituents of concern at concentrations equal to
or greater than the listing levels established for these constituents,
then you would determine that your tested wastes are nonhazardous. Once
you have determined your tested wastes to be nonhazardous, you would
decide if these wastes are representative of the wastes that you will
generate for the remainder of the year. If your tested wastes are
representative (or you can
[[Page 10116]]
reliably determine that these wastes exhibited the maximum
concentrations for the constituents of concern), then you could
determine that the wastes (or certain type of wastes) that you generate
for the remainder of the year are also nonhazardous. As stated earlier,
following a nonhazardous determination, you would have an obligation to
ensure that your wastes continue to meet all of the conditions (i.e.,
constituents of concern in your wastes remain below listing levels) and
requirements (i.e., records that support a nonhazardous determination)
for the wastes to be deemed nonhazardous. We are also proposing annual
follow-up sampling and analysis for wastes that you determine to be
nonhazardous to check that these wastes continue to remain
nonhazardous. However, if any of your waste samples contain any of the
constituents of concern at a concentration equal to or greater than the
listing level set for that constituent, your wastes would be listed
hazardous wastes and are thereby subject to all applicable RCRA
Subtitle C hazardous waste requirements.
We are proposing that the maximum concentration of any constituent
detected in any sample must be below the established listing level in
order for you to determine that the waste is nonhazardous. We are
proposing this approach because we believe it is the most
straightforward to ensuring concentrations are below risk-based listing
levels. However, we request comment on whether the generator should be
allowed to average the concentrations of constituents detected in
multiple waste samples taken from some quantity of waste generated or
collected over a certain period of time (e.g., 60 days). Under that
approach, the generator would calculate concentrations using an upper
confidence limit on the mean (e.g., 95th percentile) to compare to the
listing levels established for the constituents.
We also request comment on whether the annual testing requirement
should be continued beyond three years, if the generator determines the
wastes to be nonhazardous for three consecutive years. Following
suspension of annual testing requirements, the generator would still be
liable if testing by EPA or an authorized State finds the waste to be
hazardous.
2. Using Knowledge of The Wastes
Where testing is not required, or as a supplement to testing, we
are proposing that you could use knowledge of your wastes (e.g.,
knowledge of the constituents in your wastes based on existing sampling
and analysis data and/or information about raw materials used,
production processes used, and degradation products formed) to conclude
that concentrations for the constituents of concern in your waste would
be below the listing levels (nonhazardous waste).
D. How Would The Proposed Contingent Management Listing for Liquid
Wastes be Implemented?
Under this proposed listing, paint manufacturing waste liquids that
meet the K180 listing description would be hazardous wastes unless
managed exclusively in tanks or containers prior to discharge to a POTW
or under a NPDES permit. If your liquid paint manufacturing wastes are
going to be stored or treated in units other than tanks or containers,
then they would be hazardous wastes unless you have determined (using
the procedures described in Section C) that the constituents of concern
in the waste liquids are below the listing levels. Therefore, you would
need to determine as soon as the paint manufacturing waste liquids are
generated whether they will be stored or treated in units other than
tanks or containers. If your paint manufacturing waste liquids will be
stored or treated in units other than tanks or containers, your wastes
would be subject to the management requirements discussed in Section B
above. If you are storing or treating paint manufacturing waste liquids
on-site in tanks or containers prior to off-site disposal, you would
need to maintain documentation showing that the wastes will be stored
or treated exclusively in tanks or containers off-site prior to their
discharge to a POTW or discharge under a NPDES permit. If the off-site
disposal facility does not store or treat your paint manufacturing
wastes exclusively in tanks or containers and the waste contains levels
of constituents at or above the risk-based listing levels, then your
wastes would be hazardous and you would need to store the wastes in
accordance with the Subtitle C requirements applicable to storage of a
hazardous waste.
E. What Records Would I Need to Keep On-site to Support a Nonhazardous
Determination for My Wastes?
To support a nonhazardous determination, we are proposing that you
must keep records of the total annual quantity of paint production
waste solids and liquids from tank and equipment cleaning operations
that use solvents, water, and/or caustic; emission control dusts or
sludges; wastewater treatment sludges and off specification product for
the most recent three years from the effective date of the final rule.
If you generate a total annual quantity of paint manufacturing wastes
that exceeds 40 metric tons for paint manufacturing waste solids or 100
metric tons for paint manufacturing waste liquids, we are proposing
that you keep the following records on-site for the most recent three
years:
1. The documentation supporting a determination that wastes are
nonhazardous based on knowledge that they do not contain any of the
constituents of concern.
2. If you determine that wastes are nonhazardous based on
testing, then you must keep the following records on-site:
a. The sampling and analysis plan used for collecting and
analyzing samples representative of your wastes, including detailed
sampling methods used to account for spatial and temporal
variability of the wastes, and sample preparative, cleanup (if
necessary) and determinative methods.
b. The sampling and analysis data (including QA/QC data) and
knowledge (if used to determine that one or more constituents of
concern are not present in the wastes) that support a nonhazardous
determination for your wastes (for the most recent three years of
testing).
3. If storing or treating paint manufacturing waste liquids on-
site in tanks or containers prior to off-site disposal, the
documentation showing that the paint manufacturing waste liquids
will be stored or treated solely in tanks or containers off-site
before discharge by a facility to a POTW or discharge under an NPDES
permit.
We request comment on the adequacy of the above recordkeeping
requirements to support a nonhazardous determination.
F. What Would Happen if I Do Not Meet The Recordkeeping Requirements
for The Wastes That I Have Determined Are Nonhazardous?
We are proposing to require recordkeeping under the authority of
sections 2002 and 3007 of RCRA. These are requirements and not
conditions of the waste being nonhazardous. A condition is a standard
that you or your waste must meet in order for your waste to become or
remain nonhazardous. If a condition is not fulfilled, then the waste is
hazardous and subject to RCRA Subtitle C requirements. A requirement is
an obligation whose violation would not affect the nonhazardous status
of the waste, but would be a violation under RCRA. Failure to comply
with these requirements could result in an enforcement action under
section 3008 of RCRA. This section of the statute authorizes the
imposition of civil penalties in an amount up to $27,500 for each day
of noncompliance.
[[Page 10117]]
G. Could I Treat My Wastes to Below Listing Concentrations and Then
Determine That My Wastes Are Nonhazardous?
1. Paint Manufacturing Waste Solids
If your paint manufacturing waste solids are hazardous (K179) at
the point of generation, we are proposing that you could treat the
wastes to make them nonhazardous (i.e., remove the K179 hazardous waste
code from your wastes). However, if your wastes are K179, they would be
required to be treated to meet the proposed LDR treatment standards
(see Section VI D.) before placement in a land-based unit. Following
LDR treatment, you could choose to use the initial hazardous waste
determination procedures for K179 wastes (see Section C above) to
determine if your treated waste residuals are nonhazardous. If your
treated waste residuals are determined to be nonhazardous, they would
no longer be subject to the requirements of Subtitle C. In other words,
the derived from hazardous waste code would no longer attach to such
treatment residuals.
2. Paint Manufacturing Waste Liquids
If your paint manufacturing waste liquids are hazardous (K180) at
the point of generation because the concentration of the constituents
of concern are not below the listing levels and they are not stored or
treated solely in tanks or containers prior to discharge, then they
would also be required to be treated to meet the proposed LDR treatment
standards (see Section VI.D). However, we are proposing that the
treatment of the K180 liquid wastes (e.g., to meet the proposed LDR
treatment standards) would not result in the removal of the K180
hazardous waste code from your liquid residual wastes. This is because
the proposed listing levels for K180 are for the waste prior to any
mixing and would necessarily be higher than the levels of the
constituents that may exit in the liquid paint wastes mixed with other
wastewaters in an off-site impoundment. Therefore, we believe that the
use of listing levels for K180 would not protect against paint
manufacturing waste liquids being placed on land.
VI. Proposed Treatment Standards Under RCRA's Land Disposal
Restrictions (LDRs)
A. What Are EPA's LDRs?
The RCRA statute requires EPA to establish treatment standards for
all wastes destined for land disposal. These are the so called ``land
disposal restrictions'' or LDRs. For any hazardous waste identified or
listed after November 8, 1984, EPA must promulgate LDR prohibitions and
treatment standards within six months of the date of identification or
final listing (RCRA section 3004(g)(4), 42 U.S.C. 6924(g)(4)). RCRA
also requires EPA to set as these treatment standards ``* * * 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). Once a hazardous waste is
prohibited, the statute provides only two options for legal land
disposal: meet the treatment standard for the waste prior to land
disposal, or dispose of the waste in a land disposal unit that
satisfies the statutory no migration test. A no migration unit is one
from which there will be no migration of hazardous constituents for as
long as the waste remains hazardous. RCRA sections 3004 (d), (e), (f),
and (g)(5).
B. How Does EPA Develop LDR Treatment Standards?
To establish LDR treatment standards, EPA first identifies the best
demonstrated available technology (BDAT) for the hazardous constituents
present in the hazardous waste, and then determines what constituent
concentrations can be achieved by the technology or technologies
identified as BDAT.
EPA typically has established treatment standards based on
performance data from the treatment of the waste at issue, if such data
are available, and also from the treatment of wastes with similar
chemical and physical characteristics or similar concentrations of
hazardous constituents. Treatment standards typically cover both
wastewater and nonwastewater waste forms on a constituent-specific
basis. The constituents selected for regulation under the LDR program
are not necessarily limited to those present in a proposed listing, but
also may include those constituents or parameters that will ensure that
treatment technologies are operated properly. For listed waste EPA
identifies these as ``regulated constituents'' and they appear
individually in the Table at 40 CFR 268.40, along with their respective
treatment standards.
EPA may develop and promulgate either technology-specific treatment
standards or numerical treatment standards. Should EPA elect to use
technology-specific standards (i.e., mandate use of a particular type
of treatment technology), all wastes that meet the listing designations
would have to be treated by the technology or technologies specified
before disposal. These technologies are also identified in the Table at
Sec. 268.40 and are further described in Sec. 268.42. Should EPA elect
to use numerical treatment standards, the Agency allows the use of any
technology (other than impermissible dilution) to comply with the
treatment standards.
With the advent of the so-called Universal Treatment Standards
(UTS) (the same numerical standards for common hazardous constituents
in all prohibited hazardous wastes), EPA has somewhat refined this
approach. Thus some of the evaluation of treatability goes to the issue
of how well the UTS express potential treatability of a prohibited
hazardous waste. Given that the UTS typically reflect performance of
the best treatment technologies and minimizing threats, and the
enormous savings in administrative expense to both the regulated
communities and to EPA, EPA seeks to apply the UTS wherever technically
justified. See generally 59 FR 47988-991 (September 19, 1994).
After developing the LDR treatment standards, we must also
determine if adequate treatment capacity is available to treat the
expected volumes of wastes. If so, the LDR treatment standards become
effective essentially at the same time a listing does. If not, EPA may
grant up to a two-year national capacity variance (NCV) during which
time the LDR treatment standards are not effective.
For a more detailed overview of the Agency's approach for
developing treatment standards for hazardous wastes, see the final rule
on solvents and dioxins (51 FR 40572, November 7, 1986) and section
III.A.1 of the preamble to the final rule that set land disposal
restrictions for the ``Third Third'' wastes (55 FR 22535, June 1,
1990). EPA also has explained its BDAT procedures in ``Best
Demonstrated Available Technology (BDAT) Background Document for
Quality Assurance/Quality Control Procedures and Methodology (EPA/OSW,
October 23, 1991)''. This document is available in the docket
supporting this rulemaking.
C. What Treatment Standards Are Proposed?
For the hazardous constituents found in wastes from the manufacture
of
[[Page 10118]]
paints, hazardous waste numbers K179 and K180, we are proposing to
transfer existing numerical or universal treatment standards to the
hazardous constituents identified in the wastes, with the exception of
formaldehyde and styrene. We believe that it is technically feasible to
apply these existing numerical standards to the hazardous constituents
of K179 and K180, because the waste compositions are similar to other
wastes for which applicable treatment technologies have been
demonstrated. Due to the uncertainties in our assessment of the
management of paint manufacturing waste liquids in surface
impoundments, we are also considering an alternative proposal not to
list paint manufacturing waste liquids. We describe this alternative
elsewhere in this notice (see Section IV.D). If we do not list wastes
under K180, then there would be no need for any standards for
formaldehyde or styrene. The following discussion describes the
approach for treatment standards assuming that paint manufacturing
waste liquids are listed under K180.
The hazardous constituents formaldehyde and styrene do not have
existing numerical standards. For formaldehyde, we are proposing to
require treatment by designated methods. When formaldehyde is present
in K180 at levels triggering the listing, formaldehyde thus would be
treated by the required technologies. (The other hazardous constituents
must, of course, be treated to meet the applicable numerical
standards.) Wastes that do not trigger the listing based on
formaldehyde would not be subject to the formaldehyde technology
requirement, but would be subject to all other numerical standards. The
technology standards proposed for formaldehyde-listed K180 wastewaters
are wet air oxidation (WETOX) or chemical or electrolytic oxidation
(CHOXD) followed by carbon adsorption (CARBN); or combustion (CMBST).
For nonwastewaters forms of K180, the technology standard proposed is
combustion. These are the same treatment standards currently applicable
to discarded product, off specification, container residues, and spill
residues of formaldehyde (EPA hazardous waste U122).
For styrene, we are proposing numerical standards developed for
this rulemaking. We are proposing a wastewater standard of 0.028 mg/L
based on activated sludge treatment and a nonwastewater standard of
28.0 mg/kg based on thermal destruction of sludge. Alternatively, we
propose the transfer of the ethylbenzene treatment standards of 0.057
mg/L for wastewaters, and 10 mg/kg for nonwastewaters, because of its
structural similarity and similar physical properties with styrene
similar treatment technologies have been demonstrated. Ethylbenzene and
styrene have the same number of carbon atoms, and differ only in that
styrene has one additional double bond and hence two fewer hydrogen
atoms in its structure. See supporting background documents for the
additional discussion on the derivation of the UTS for this new
constituent.
Wastes identified as K179 or K180 may already be subject to
hazardous waste regulation, because they exhibit a characteristic or
are listed F001-F005 wastes. If promulgated, the treatment standards
for K179 and K180 will apply in addition to any treatment requirements
the wastes are currently subject to. Section 268.9(b) of current rules
states that if a treatment standard for a listed waste which also
exhibits a characteristic addresses the hazardous constituent which
causes the waste to exhibit the characteristic, then, the waste is only
subject to the treatment standard for the listed waste. Applied to
these paint manufacturing wastes, therefore, the most likely result is
that these wastes would be subject only to the treatment standards for
K179 and K180 assuming that presence of organic hazardous constituents
addressed in the treatment standard for the listed waste causes these
wastes to exhibit a characteristic.
The treatment standards proposed are based on technology
performance and not upon the listing levels of concern derived from the
Paint Risk Assessment. In the Hazardous Waste Identification Rule
proposed November 19, 1999, we outlined ways in which the HWIR risk
assessment could be used to develop risk-based LDR levels (see 64 FR
63444, November 19, 1999), because the HWIR risk assessment evaluated
the potential for constituent migration through the most significant
environmental fate and transport pathways, looked at the total impact
of those pathways, and considered a great number of ecological
benchmarks. In the Paint Risk Assessment, we also have a substantial
multipathway risk assessment that could potentially lead to treatment
standards which could be either more lenient or stricter than current
standards.
However, the listing levels proposed for K180 are for the waste
prior to any mixing, and would necessarily be higher than the levels of
the constituents that may exist in the off-site impoundment. Therefore,
we believe the listing levels for K180 may not be appropriate for use
in estimating minimized threat levels, because they do not correspond
to risk-based levels for the diluted waste in the impoundment. The
levels indicated would not be applicable as ``universal'' risk-based
treatment standards (as we hope HWIR could eventually be).
Our preference is to develop a single set of treatment levels that
would be applicable to all hazardous wastes. Waste-by-waste modeling
would not only be highly resource intensive, but could lead to the
potentially false conclusion that higher levels are justified only to
realize that if we look at a range of wastes together we might conclude
that more stringent treatment standards are needed to minimize threat
to human health and the environment. Therefore, we believe the proposed
listing levels are not minimized threat levels across all wastes and
have chosen to propose treatment standards based on the performance of
the best determined available technology (BDAT). We believe that there
is still uncertainty as to what quantified levels minimize threats to
human health and the environment, and therefore, we are proposing
standards based on the performance of the BDAT. See HWTC vs. EPA.886 f.
2d 355, 361-63 (D.C. Cir. 1989) (accepting this approach).
The proposed treatment standards are set out in Table VI-1 below.
Where EPA is proposing numerical concentration limits the use of any
technology capable of achieving the proposed treatment standards would
be allowed, except those treatment or reclamation practices
constituting land disposal or impermissible dilution (see 40 CFR
268.3). As stated above, when formaldehyde is present in K180 at levels
triggering the listing, we are proposing that formaldehyde must be
treated by the required technologies. The other hazardous constituents
would, of course, be treated to meet the applicable numerical
standards.
[[Page 10119]]
Table VI-1.--Treatment Standards for Hazardous Waste K179 and K180
--------------------------------------------------------------------------------------------------------------------------------------------------------
Regulated hazardous constituent Wastewaters Nonwastewaters
--------------------------------------------------- -------------------------------------------------------------------------
K179 solids K180 liquids Concentration in mg/kg \4\ unless
Common name CAS \1\ No. Concentration in mg/L,\2\ or noted as ``mg/L TCLP'', or
technology code \3\ technology code \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Acrylamide........................... 79-06-1 X X 19................................. 23
Acrylonitrile........................ 107-13-1 X X 0.24............................... 84
n-Butyl alcohol...................... 71-36-3 ............ X 5.6................................ 2.6
Ethyl benzene........................ 100-41-4 ............ X 0.057.............................. 10
Formaldehyde \5\..................... 50-00-0 ............ X (WETOX or CHOXD) fb CARBN; or CMBST CMBST
Methylene chloride................... 75-09-2 ............ X 0.089.............................. 30
Methyl isobutyl ketone............... 108-10-1 X X 0.14............................... 33
Methyl methacrylate.................. 80-62-6 X X 0.14............................... 160
Styrene.............................. 100-42-5 ............ X 0.028.............................. 28
Toluene.............................. 108-88-3 ............ X 0.080.............................. 10
Xylenes--mixed isomers (sum of o-, m- 1330-20-7 ............ X 0.32............................... 30
, and p-xylene concentrations).
Antimony............................. 7440-36-0 X X 1.9................................ 1.15 mg/L TCLP
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ CAS means Chemical Abstract Services. When the waste code and/or regulated constituents are described as a combination of a chemical with its salts
and/or esters, the CAS number is given for the parent compound only.
\2\ Concentration standards for wastewaters are expressed in mg/L and are based on analysis of composite samples.
\3\ All treatment standards expressed as a Technology Code or combination of Technology Codes are explained in detail in 40 CFR 268.42 Table 1-
Technology Codes and Descriptions of Technology-Based Standards.
\4\ Except for Metals (EP or TCLP) and Cyanides (Total and Amenable) the nonwastewater treatment standards expressed as a concentration were
established, in part, based upon incineration in units operated in accordance with the technical requirements of 40 CFR Part 264, Subpart O, or Part
265, Subpart O, or based upon combustion in fuel substitution units operating in accordance with applicable technical requirements. A facility may
comply with these treatment standards according to provisions in 40 CFR 268.40(d). All concentration standards for nonwastewaters are based on
analysis of grab samples.
\5\ Wastes that do not exceed the Sec. 261.32 listing criteria for this constituent are not subject to the treatment technology requirements, but are
subject to all other numerical standards.
D. Other LDR-Related Provisions
1. F039 Multisource Leachate and Universal Treatment Standards
F039 applies to multiple listed hazardous waste landfill leachates
in lieu of the original waste codes, and F039 wastes are subject to
numerical treatment standards applicable to all listed wastes. To
maintain the regulatory implementation benefits of having one waste
code for multisource leachate, the treatment standards for F039 must be
updated to include the constituents of newly listed wastes. Otherwise,
multiple waste codes would again be applicable. Therefore, we propose
to add to F039 the additional constituents acrylamide and styrene. We
also propose to add the numerical standards for styrene to the
Universal Treatment Standards of 40 CFR 268.48 \45\ Characteristic
wastes are already subject to treatment standards for acrylamide. As a
result, characteristic wastes subject to treatment requirements for
underlying hazardous constituents will also have to comply with these
treatment standards.
---------------------------------------------------------------------------
\45\ As noted previously, we are considering an alternative
proposal not to list paint manufacturing waste liquids. If we do not
like K180, then there would be no need to add styrene to the F039 or
UTS standards.
---------------------------------------------------------------------------
We are proposing these changes, because acrylamide and styrene are
toxic constituents. When paint manufacturing (or production) wastes are
managed with other wastes at commercial treatment facilities, the
combined waste residues that result for disposal would need to meet all
part 268 requirements, including requirements for C disposal, if the
paint listing codes were retained or mixed with other listed wastes.
The new listing codes may also be retained if treatment meets only the
LDR standards and not the listing levels. Thus, leachates that could be
subject to multiple codes could be formed. By adding these constituents
to F039, the regulatory benefits of having one waste code for
multisource leachate is maintained.
Based on the treatment studies compiled for acrylamide and styrene,
we believe the proposed treatment standards for these constituents can
readily be achieved in the F039 leachate wastes, and in characteristic
wastes. Nevertheless, we request comments on this assumption.
E. Is There Treatment and Management Capacity Available for These
Proposed Newly Identified Wastes?
1. What Is a Capacity Determination?
EPA must determine whether adequate alternative treatment capacity
exists nationally to manage the wastes subject to LDR treatment
standards. RCRA Section 3004(h)(2). Thus, LDRs to be made effective
immediately--in this case when the new listings are effective
(typically 6 months after the new listings are published in the Federal
Register)--unless EPA grants a national capacity variance from the
otherwise-applicable date and establishes a different date (not to
exceed two years beyond the statutory deadline) based on ``the earliest
date on which adequate alternative treatment, recovery, or disposal
capacity which protects human health and the environment will be
available'' (RCRA Section 3004(h)(2), 42 U.S.C. 6924(h)(2)).
Our capacity analysis methodology focuses on the amount of waste
currently disposed on the land, which will require alternative or
additional treatment as a result of the LDRs. The quantity of wastes
that is not disposed on the land, such as treatment in tanks, is not
included in the quantities requiring additional treatment as a result
of the LDRs. Also, land-disposed
[[Page 10120]]
wastes that do not require alternative or additional treatment (i.e.,
those that currently are treated to meet the LDR treatment standards)
are excluded from the required capacity estimates. Land-disposed wastes
requiring alternative or additional treatment or recovery capacity that
is available on-site or within the same company also are excluded from
EPA's estimates of needed commercial capacity. EPA then compares the
resulting estimates of required commercial capacity to estimates of
available commercial capacity. If adequate commercial capacity exists,
the waste is restricted from further land disposal. If protective
alternative capacity does not exist, EPA has the authority to grant a
national capacity variance.
In making the estimates described above, the volume of waste
requiring treatment depends on the current waste management practices
employed by the waste generators before this proposed regulation is
promulgated and becomes effective. Data on waste management practices
for these wastes were collected during the development of this proposed
rule. However, we realize that as the regulatory process proceeds,
generators of these wastes may decide to minimize or recycle their
wastes or otherwise alter their management practices. Thus, we will
monitor changes and update data on current management practices as
these changes will affect the volume of wastes ultimately requiring
commercial treatment or recovery capacity.
The commercial hazardous waste treatment industry may change
rapidly. For example, national commercial treatment capacity changes as
new facilities come on line or old facilities go off line, and as new
units and new technologies are added at existing facilities. 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''--company owned--facility). Thus,
we also continue to update and monitor changes in available commercial
treatment capacity.
For wastes required to meet today's proposed treatment standards,
we request data on the annual generation volumes and characteristics of
wastes affected by this proposed rule, including proposed hazardous
wastes K179 and K180 in wastewater and nonwastewater forms. We also
request data on soil or debris contaminated with these wastes,
residuals generated from the treatment or recycling of these wastes,
and the current and planned management practices for the wastes, waste
mixtures, and treatment residuals.
For available capacity to meet the LDR requirements, we request
data on the current treatment or recovery capacity capable of treating
these wastes, facility and unit permit status related to treatment of
the proposed wastes, and any plans that facilities may expand or reduce
existing capacity or construct new capacity. In addition, we request
information on the time and necessary procedures required for permit
modification for generators or commercial treatment or disposal
facilities to manage the wastes, required changes for operating
practices due to the proposed listings or proposed additional
constituents to be regulated in the wastes, and any waste minimization
activities associated with the wastes. Of particular interest to us are
chemical and physical constraints of treatment technologies for these
wastes and any problems for disposing of these wastes. Also of interest
are any analytical difficulties associated with identifying and
monitoring the regulated constituents in these wastes.
2. What Are The Capacity Analysis Results?
This preamble only provides a summary of the capacity analysis
performed to support this proposed regulation. For additional and more
detailed information, please refer to the ``Background Document for
Capacity Analysis for Land Disposal Restrictions: Newly Identified
Paint Production Wastes (Proposed Rule), January 2001'' (i.e., the
Capacity Background Document).
For this capacity analysis, we examined data on waste
characteristics (such as whether the waste is a solid, solvent, or an
aqueous waste) and management practices gathered for the paint
manufacturing hazardous waste listing determination. We also examined
data on available treatment or recovery capacity for these wastes. The
sources for these data are the 2000 RCRA section 3007 survey and site
visits (see the docket for this proposed regulation for more
information on these survey instruments and facility activities), the
available treatment capacity data submission that was collected in the
1990's, and the 1997 Biennial Report (BR).
We derived our estimated quantities requiring alternative or
additional treatment to meet the LDR treatment standards from the
estimated population for paint manufacturers (i.e., approximately one
thousand paint manufacturing facilities in the United States, as
discussed earlier for RCRA Section 3007 Survey (Section II.G )). K179
is paint manufacturing waste solid, so it is generated as a
nonwastewater, as defined in 40 CFR 268.2(d) and (f) (i.e.,
nonwastewaters are wastes that do not meet the criteria for wastewaters
which contain less than 1% by weight total organic carbon (TOC) and
less than 1% by weight total suspended solids (TSS)). K180 is a paint
manufacturing waste liquid and could be a nonwastewater or wastewater
form based on the above definition.
Generally, facilities may combine a variety of wastes (for example,
sludges from tank cleaning operations and wastewater treatment) and
send their wastes off to one waste management unit. Some waste types
are managed separately (for example, wastes with some value for fuel
blending). We used weighted and extrapolated universe waste quantities
from approximately one thousand paint manufacturing facilities for our
capacity analysis. After examining waste generation quantities and
their management practices, we estimated that approximately 17,000 tons
per year of K179 and K180 wastes may require alternative or additional
treatment to meet the LDR standards. This amount of waste covers the
quantities which are currently land disposed, managed in a Subtitle D
combustion unit, or uncertain on their management practices.
The quantities requiring alternative or additional treatment could
be smaller because much of the proposed and newly identified paint
manufacturing (or production) waste is mixed with existing listed and/
or characteristic wastes which already had to meet the LDR requirements
for at least some of the proposed constituents for K179 and K180
wastes. Also, most of the surveyed facilities that reported generation
of waste residuals of concern under this listing determination reported
that they recycled or reused the residuals to some extent. Furthermore,
waste generated from the production batches are also generated in
batches rather than in a continuous stream. We recognize the volume and
type of paint produced, degree of automation, amount of non land-based
recycling, age of facility, and the speed at which facilities may
change product formulations can affect types and amount of waste
generated. Therefore, the actual annual quantity of waste requiring
commercial treatment may fluctuate due to these variations. However, we
find that there is no shortfall for available commercial treatment
capacity for these wastes proposed in today's rule. For a more detailed
analysis regarding the amount of paint manufacturing (or production)
[[Page 10121]]
wastes requiring treatment to meet the LDR standards, see the Capacity
Background Document in the public docket for this proposed rule.
As discussed in the section for the LDR treatment standards, we are
proposing that numerical or technology-specific treatment standards be
applied to K179 and K180 wastes, depending on the constituent in the
wastes. For nonwastewater forms of these wastes, we anticipate that
commercially available incineration, followed by stabilization if
necessary (for antimony), can be used to meet these numerical treatment
standards. For one organic constituent (formaldehyde) in wastewater and
nonwastewater forms of K180, we are proposing to require treatment by
specified methods. For formaldehyde in K180 wastewater we are proposing
the following technologies as methods of treatment, wet air oxidation
(WETOX) or chemical or electrolytic oxidation (CHOXD) followed by
carbon adsorption (CARBN); or combustion (CMBST). For this constituent
in the nonwastewater form of K180, the required technology standard
proposed is combustion. We assume that facilities would achieve waste
treatment standards using combustion, stabilization, or both for K179
and K180 wastes. The quantity of commercially available combustion
capacity for sludge, solid, and liquids is well over one million tons
per year based on 1997 Biennial Report data. The quantity of
commercially available stabilization capacity is at least seven million
tons per year based on 1995 Biennial Report data. Also, based on the
data submittals in the early 1990's and 1997 BR data, we estimated that
at least 34 million tons per year of commercial wastewater treatment
capacity are available. Please note that facilities could use any
available technologies (except impermissible dilution) to achieve the
LDR numerical standards for these wastes.
Based on the results of the RCRA section 3007 survey and the site
visits, we did not identify any paint manufacturing facilities that
manage these proposed wastes in on-site surface impoundments. From the
available information, we found that at least one wastewater treatment
plant accepted proposed paint manufacturing waste liquids (K180) from
the paint production industry, and the facility managed these wastes in
a lined surface impoundment. Assuming such an impoundment satisfies
requirements of section 3005(j)(11) (in essence, meets minimum
technological requirements and is dredged annually), such wastes would
not require treatment. If any wastes are managed in an impoundment not
satisfying requirements of 3005(j)(11) (e.g., an unlined surface
impoundment) of a wastewater treatment system, the wastes would be
subject to land disposal prohibitions. However, we anticipate that very
few facilities, if any, would manage the newly identified paint
manufacturing wastes in such impoundments.
Based on the foregoing, we expect that sufficient capacity exists
to treat the proposed K179 and K180 wastes that would require
alternative or additional treatment. Therefore, we are proposing to not
grant a national capacity variance for these wastes.
Further, soil and debris contaminated with these newly identified
wastes may be subject to the LDRs (see LDR Treatment Standards for Soil
in LDR Phase IV Final Rule, 63 FR 28602, May 26, 1998; 40 CFR 268.45
Treatment Standards for Hazardous Debris), but we believe that the
contaminated soil and debris, if any, would not require substantial
commercial treatment capacity. There are no data showing such
contaminated soil and debris are currently generated. We expect that
the majority of contaminated soil and debris, if generated, will be
managed on-site. Therefore, we are not proposing to grant a national
capacity variance for hazardous soil and debris contaminated with these
wastes covered under this proposal.
Based on the RCRA section 3007 Survey conducted in early 2000
(which collected 1998 data), there are no data showing that the newly
proposed wastes are managed by underground injection wells. Also, based
on the 2000 RCRA section 3007 Survey, there are no data showing mixed
radioactive wastes associated with the proposed listings. We are
proposing to not grant a national capacity variance for underground
injected wastes, mixed radioactive wastes (i.e., radioactive wastes
mixed with K179 and K180), or soil and debris contaminated with these
mixed radioactive wastes, if such wastes are generated.
Therefore, we propose that LDR treatment standards thus become
effective when the listing determinations become effective for the
wastes covered under today's rule. This conforms to RCRA section
3004(h)(1), which indicates that land disposal prohibitions must take
effect immediately when there is sufficient treatment or disposal
capacity available for the wastes. However, we may need to revise
capacity analyses or capacity variance decisions if final listing
determinations are changed or if we receive data and information to
warrant any revision.
We request comments on the estimated quantities requiring
alternative treatment and information on characteristics of the
affected wastes, management practices for these wastes, and available
treatment, recovery or disposal capacity for the wastes. We also
request comments on whether any facility uses surface impoundment or
underground injection to manage these wastes. In addition, we solicit
comments on our decision not to grant a national capacity variance for
any of the affected wastes. We will consider all available data and
information provided during the public comment period and revise our
capacity analysis accordingly in making the final capacity
determinations. Please note that the ultimate volumes of wastes
estimated to require alternative or additional commercial treatment may
change if the final listing determinations change. Should this occur,
we will revise the capacity analysis accordingly.
3. What Is the Available Treatment Capacity for Other Wastes Subject to
Revised UTS and F039 Standards?
With respect to the revisions to the F039 and UTS lists, as
discussed earlier in the section on K179 and K180 treatment standards,
we are proposing to add acrylamide and styrene to the list of regulated
constituents in F039 (40 CFR section 268.40). We are also proposing to
add styrene to the UTS table (40 CFR section 268.48). Acrylamide is
currently listed in the Appendix VIII of part 261. EPA is proposing to
add styrene in the Appendix VIII as discussed in the earlier section
(Section II). We have estimated what portion of the F039 or
characteristic wastes (which require treatment of underlying hazardous
constituents to UTS levels) may be required to meet these new treatment
standards. We request comments on the estimates, the appropriate means
of treatment (if necessary), and the sufficiency of available treatment
capacity for the affected wastes by the addition of these constituents
to the F039 and UTS lists.
When changing the treatment requirements for wastes already subject
to LDR (including F039 under 40 CFR 261.31 and characteristic wastes
under 40 CFR 261.24) for which the potential capacity variance periods
have expired, EPA no longer has authority to use RCRA section
3004(h)(2) to grant a capacity variance to these wastes. However, EPA
is guided by the overall objective of section 3004(h), namely that
treatment standards which best
[[Page 10122]]
accomplish the goal of RCRA section 3004(m) (to minimize threats posed
by land disposal) should take effect as soon as possible, consistent
with availability of treatment capacity.
We expect that only a limited quantity of hazardous waste leachate,
if any, may be generated from the disposal of newly-proposed K179 and
K180 wastes and added to the generation of leachates from other
multiple restricted hazardous wastes already subject to LDR.
For the amount of characteristic wastes or leachates generated from
those previously regulated hazardous wastes that would be subject only
to the new treatment standards for these constituents, we evaluated the
universe of wastes that might be impacted by revisions to the lists of
regulated constituents for F039 and UTS based on limited information.
Based on 1997 Biennial Report data and some assumptions of waste
compositions and their potential for land disposal, we were able to
estimate the potential need for additional treatment. For example, we
estimated an upper bound of 7,000 tons per year of nonwastewaters mixed
with other waste codes, the F039 leachate from which would be
potentially impacted by the revision to the F039 treatment standards.
In a similar fashion, we estimated that approximately 250,000 tons per
year of characteristic nonwastewaters potentially might be affected by
the proposed changes.
These upper bound estimates are most likely significantly
overstated since only a portion of each estimated waste volume may
contain the proposed additional constituents at concentrations above
the proposed level specified in the UTS table and the F039 list. The
estimates assume that these constituents are present at levels above
the proposed treatment standards in all of these F039 and
characteristically hazardous wastes and require alternative treatment,
when it is likely that this may be true in only a small subset of the
cases (as described in the Capacity Background Document). Furthermore,
EPA does not anticipate that waste volumes subject to treatment for
F039 or characteristic wastes would significantly increase because
waste generators already are required to comply with the treatment
requirements for other already regulated organic or metal constituents
that may be present in the wastes. The volumes of wastes for which
additional treatment is needed solely due to the addition of these
constituents to the F039 and UTS lists are therefore expected to be
small. See the Capacity Background Document for detailed analysis.
Even if we have underestimated the projected volume of wastes
requiring treatment, we believe that there still would be no shortage
of treatment capacity. Based on data submittals in the early 1990's and
1997 BRS data, EPA has estimated that at least 34 million tons per year
of commercial wastewater treatment capacity are available, and
approximately 1.6 million tons per year of liquid, sludge, and solid
commercial combustion capacity are available. Also, as discussed
earlier in this section, there are seven million tons of available
stabilization capacity. These are well above the quantities of F039 or
characteristic wastes potentially requiring treatment for the proposed
additional constituents even under the conservative screening
assumptions described above. Therefore, we are proposing a decision not
to delay the effective date for adding these constituents to the lists
of constituents for F039 and UTS.
We request comments on our proposed decision to not delay the
effective date for adding these constituents to the lists of
constituents for F039 and UTS. We request data on the annual generation
volumes and characteristics of wastes affected by the proposed changes
to UTS and F039 in wastewater and nonwastewater forms (if any), and the
current and planned management practices for the wastes, waste
mixtures, and treatment residuals. We also request data on the current
treatment or recovery capacity available for treating the affected
wastes.
VII. State Authority and Compliance
A. How Are States Authorized Under RCRA?
Under section 3006 of RCRA, EPA may authorize qualified States to
administer and enforce the RCRA hazardous waste 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 finalized in this notice) take effect in
authorized States at the same time that they take effect in non-
authorized States. While States must still adopt HSWA-related
provisions as State law to retain final authorization, 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.
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. See also 40 CFR 271.1(I). For those Federal program changes,
both HSWA and non-HSWA, that are less stringent or reduce the scope of
the Federal program, States are not required to modify their programs.
Less stringent regulations, both HSWA and non-HSWA, do not go into
effect in authorized States until those States adopt them and are
authorized to implement them.
B. How Would This Rule Affect State Authorization?
We are proposing today's rule pursuant to HSWA authority. The
listing of the new K-wastes is promulgated pursuant to RCRA section
3001(e)(2), a HSWA provision. Therefore, we are adding this rule to
Table 1 in 40 CFR 271.1(j), which identifies the Federal program
requirements that are promulgated pursuant to HSWA and take effect in
all States, regardless of their authorization status. The land disposal
restrictions for these wastes are promulgated pursuant to RCRA section
3004(g) and (m), also HSWA provisions. Table 2 in 40 CFR 271.1(j) is
modified to indicate that these requirements are self-implementing.
States may apply for either interim or final authorization for the HSWA
provisions in 40 CFR 271.1(j), as discussed below. Until the States
receive authorization for these more stringent HSWA provisions, EPA
would implement them.
A State submitting a program modification for the portions of this
proposed rule promulgated pursuant to
[[Page 10123]]
HSWA authority could apply to receive either interim authorization
under RCRA section 3006(g) or final authorization under 3006(b), if the
State requirements are, respectively, substantially equivalent or
equivalent to EPA's requirements. States can only receive final
authorization for program modifications implementing non-HSWA
requirements. The procedures and schedule for final authorization of
State program modifications are described in 40 CFR 271.21. It should
be noted that all HSWA interim authorizations are currently 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
would need to modify their programs to adopt this proposed regulation
is determined by the date of promulgation of a final rule in accordance
with section 271.21(e)(2). Table 1 at 40 CFR 271.1 is amended
accordingly. Once EPA approves the modification, the State requirements
would 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 finalized 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. In implementing the HSWA
requirements, EPA will work with the States under agreements to avoid
duplication of effort.
C. Who Would Need to Notify EPA That They Have a Hazardous Waste?
Under RCRA Section 3010, the Administrator may require all persons
who handle hazardous wastes to notify EPA of their hazardous waste
management activities within 90 days after the wastes are identified or
listed as hazardous. This requirement may be applied even to those
generators, transporters, and treatment, storage, and disposal
facilities (TSDFs) that have previously notified EPA with respect to
the management of other hazardous wastes. The Agency is proposing to
waive this notification requirement for persons who handle wastes that
are covered by today's listings and have already (1) notified EPA that
they manage other hazardous wastes, and (2) received an EPA
identification number. However, any person who generates, transports,
treats, stores, or disposes of these wastes and has not previously
received an EPA identification number would need to obtain an
identification number pursuant to 40 CFR 262.12 to generate, transport,
treat, store, or dispose of these hazardous wastes 90 days after the
effective date.
D. What Would Generators and Transporters Have to Do?
Once a final rule is promulgated, persons that generate newly
identified hazardous wastes may be required to obtain an EPA
identification number if they do not already have one (as discussed
above). In order to be able to generate or transport these wastes after
the effective date of this rule, generators of the wastes listed today
would be subject to the generator requirements set forth in 40 CFR part
262. These requirements include standards for hazardous waste
determination (40 CFR 262.11), compliance with the manifest (40 CFR
262.20 to 262.23), pretransport procedures (40 CFR 262.30 to 262.34),
generator accumulation (40 CFR 262.34), record keeping and reporting
(40 CFR 262.40 to 262.44), and import/export procedures (40 CFR 262.50
to 262.60). The generator accumulation provisions of 40 CFR 262.34
allow generators to accumulate hazardous wastes without obtaining
interim status or a permit only in units that are container storage
units or tank systems. These existing regulations also place a limit on
the maximum amount of time that wastes can be accumulated in these
units. If, however, the wastes covered in today's proposed rule are
managed in units that are not tank systems or containers, then these
units would be subject to the permitting requirements of 40 CFR parts
264 and 265, and the generator is required to obtain interim status and
seek a permit (or modify interim status or a permit, as appropriate).
Also, current regulations require that persons who transport newly
identified hazardous wastes to obtain an EPA identification number as
described above; such transporters will be subject to the transporter
requirements set forth in 40 CFR part 263.
E. Which Facilities Would Be Subject to Permitting?
1. Facilities Newly Subject to RCRA Permit Requirements
Facilities that treat, store, or dispose of wastes that are subject
to RCRA regulation for the first time by this proposed rule (that is,
facilities that have not previously received a permit pursuant to
Section 3005 of RCRA and are not currently operating pursuant to
interim status), could be eligible for interim status (see section
3005(e)(1)(A)(ii) of RCRA). To obtain interim status based on
treatment, storage, or disposal of such newly identified wastes,
eligible facilities would be required to comply with 40 CFR 270.70(a)
and 270.10(e) by providing notice under section 3010 and submitting a
Part A permit application no later than 6 months after date of
publication of the final rule. Such facilities would be subject to
regulation under 40 CFR part 265 until a permit is issued.
In addition, under Section 3005(e)(3) and 40 CFR 270.73(d), not
later than 6 months after date of publication of the final rule, land
disposal facilities newly qualifying for interim status under section
3005(e)(1)(A)(ii) would also need to submit a Part B permit application
and certify that the facility is in compliance with all applicable
groundwater monitoring and financial responsibility requirements. If
the facility fails to submit these certifications and a permit
application, then interim status would terminate on that date.
2. Existing Interim Status Facilities
Pursuant to 40 CFR 270.72(a)(1), all existing hazardous waste
management facilities (as defined in 40 CFR 270.2) that treat, store,
or dispose of the newly identified hazardous wastes and are currently
operating pursuant to interim status under section 3005(e) of RCRA,
would need to file an amended Part A permit application with EPA no
later than six months after date of publication of a final rule. By
doing this, the facility could continue managing the newly listed
wastes. If the facility fails to file an amended Part A application by
that date, the facility would not receive interim status for management
of the newly listed hazardous wastes and may not manage those wastes
until the facility receives either a permit or a change in interim
status allowing such activity (40 CFR 270.10(g)).
3. Permitted Facilities
Facilities that already have RCRA permits would need to request
permit
[[Page 10124]]
modifications if they want to continue managing newly listed wastes
(see 40 CFR 270.42(g)). This provision states that a permittee may
continue managing the newly listed wastes by following certain
requirements, including submitting a Class 1 permit modification
request by the date on which the waste or unit becomes subject to the
new regulatory requirements (i.e., the effective date of a final rule),
complying with the applicable standards of 40 CFR parts 265 and 266 and
submitting a Class 2 or 3 permit modification request within 180 days
of the effective date.
Generally, a Class 2 modification is appropriate if the newly
listed wastes will be managed in existing permitted units or in newly
regulated tank or container units and will not require additional or
different management practices than those authorized in the permit.
Please note that under this proposal, liquids managed in tanks or
containers would only become newly listed waste if they meet the
listing description for constituent concentration levels and if they
are not managed solely in tanks and containers and then discharged
directly from a POTW or centralized wastewater treatment facility. A
Class 2 modification requires the facility owner to provide public
notice of the modification request, a 60-day public comment period, and
an informal meeting between the owner and the public within the 60-day
period. The Class 2 process includes a ``default provision,'' which
provides that if the Agency does not reach a decision within 120 days,
the modification is automatically authorized for 180 days. If the
Agency does not reach a decision by the end of that period, the
modification is permanently authorized (see 40 CFR 270.42(b)).
A Class 3 modification is generally appropriate if management of
the newly listed wastes requires additional or different management
practices than those authorized in the permit or if newly regulated
land-based units are involved. The initial public notification and
public meeting requirements are the same as for Class 2 modifications.
However, after the end of the 60-day public comment period, the Agency
will grant or deny the permit modification request according to the
more extensive procedures of 40 CFR part 124. There is no default
provision for Class 3 modifications (see 40 CFR 270.42(c)).
Under 40 CFR 270.42(g)(1)(v), for newly regulated land disposal
units, permitted facilities must certify that the facility is in
compliance with all applicable 40 CFR Part 265 groundwater monitoring
and financial responsibility requirements no later than 6 months after
the date of publication of a final rule. If the facility fails to
submit these certifications, authority to manage the newly listed
wastes under 40 CFR 270.42(g) will terminate on that date.
For states which have not yet picked up the permit modification
tables of 40 CFR 270.42, ``major'' and ``minor'' permit modifications
should be applied as appropriate to the permit modification request.
4. Units
Units in which newly identified hazardous wastes are generated or
managed would be subject to all applicable requirements of 40 CFR part
264 for permitted facilities or 40 CFR part 265 for interim status
facilities, unless the unit is excluded from such permitting by other
provisions, such as the wastewater treatment tank exclusions (40 CFR
264.1(g)(6) and 265.1(c)(10)) and the product storage tank exclusion
(40 CFR 261.4(c)). Examples of units to which these exclusions could
never apply include landfills, waste piles, incinerators, and any other
miscellaneous units in which these wastes may be generated or managed.
5. Closure
All units in which newly identified hazardous wastes are treated,
stored, or disposed after the effective date of this regulation that
are not excluded from the requirements of 40 CFR parts 264 and 265
would be subject to both the general closure and post-closure
requirements of subpart G of 40 CFR parts 264 and 265 and the unit-
specific closure requirements set forth in the applicable unit
technical standards subpart of 40 CFR part 264 or 265 (e.g., Subpart N
for landfill units). In addition, EPA promulgated a final rule that
allows, under limited circumstances, regulated landfills or surface
impoundments to cease managing hazardous waste, but to delay Subtitle C
closure to allow the unit to continue to manage nonhazardous waste for
a period of time prior to closure of the unit (see 54 FR 33376, August
14, 1989). Units for which closure is delayed continue to be subject to
all applicable 40 CFR parts 264 and 265 requirements. Dates and
procedures for submittal of necessary demonstrations, permit
applications, and revised applications are detailed in 40 CFR
264.113(c) through (e) and 265.113(c) through (e).
VIII. CERCLA Designation and Reportable Quantities
A. What Is the Relationship Between RCRA and CERCLA?
CERCLA (Comprehensive Environmental Response, Compensation, and
Liability Act of 1980) defines the term ``hazardous substance'' to
include RCRA listed and characteristic hazardous wastes. When EPA adds
a hazardous waste under RCRA, the Agency also will add the waste to its
list of CERCLA hazardous substances. EPA establishes a reportable
quantity, or RQ, for each CERCLA hazardous substance. EPA provides a
list of the CERCLA hazardous substances along with their RQs in Table
302.4 at 40 CFR 302.4. If you are the person in charge of a vessel or
facility that releases a CERCLA hazardous substance in an amount that
equals or exceeds its RQ, then you must report that release to the
National Response Center (NRC) pursuant to CERCLA Section 103. You also
may have to notify State and local authorities.
B. How Does EPA Determine Reportable Quantities?
Under CERCLA, all new hazardous substances automatically have a
statutory one-pound RQ. EPA adjusts the RQ of a newly added hazardous
substance based on an evaluation of its intrinsic physical, chemical,
and toxic properties. These intrinsic properties--called ``primary
criteria''--are aquatic toxicity, mammalian toxicity (oral, dermal, and
inhalation), ignitability, reactivity, chronic toxicity, and potential
carcinogenicity. EPA evaluates the data for a hazardous substance for
each primary criterion. To adjust the RQs, EPA ranks each criterion on
a scale that corresponds to an RQ value of 1, 10, 100, 1,000, or 5,000
pounds. For each criterion, EPA establishes a tentative RQ. A hazardous
substance may receive several tentative RQ values based on its
particular intrinsic properties. The lowest of the tentative RQs
becomes the ``primary criteria RQ'' for that substance.
After the primary criteria RQs are assigned, EPA further evaluates
substances for their susceptibility to certain degradative processes.
These are secondary adjustment criteria. The natural degradative
processes are biodegradation, hydrolysis, and photolysis (BHP). If a
hazardous substance, when released into the environment, degrades
rapidly to a less hazardous form by one or more of the BHP processes,
EPA generally raises its RQ (as determined by the primary RQ
[[Page 10125]]
adjustment criteria) by one level. Conversely, if a hazardous substance
degrades to a more hazardous product after its release, EPA assigns an
RQ to the original substance equal to the RQ for the more hazardous
substance.
The standard methodology used to adjust the RQs for RCRA hazardous
waste streams differs from the methodology applied to individual
hazardous substances. The procedure for assigning RQs to RCRA waste
streams is based on the results of an analysis of the hazardous
constituents of the waste streams. The constituents of each RCRA
hazardous waste stream are identified in 40 CFR part 261, Appendix VII.
EPA first determines an RQ for each hazardous constituent within the
waste stream using the methodology described above. The lowest RQ value
of these constituents becomes the adjusted RQ for the waste stream.
When there are hazardous constituents of a RCRA waste stream that are
not CERCLA hazardous substances, the Agency develops an RQ, called a
``reference RQ,'' for these constituents in order to assign an
appropriate RQ to the waste stream (see 48 FR 23565, May 25, 1983). In
other words, the Agency derives the RQ for waste streams based on the
lowest RQ of all of the hazardous constituents, regardless of whether
they are CERCLA hazardous substances.
C. Is EPA Proposing to Adjust the Statutory One Pound RQ for These
Wastes?
In today's proposed rule, EPA is proposing to assign 100-pound
adjusted RQs to the K179 and K180 wastes. The RQs for each of the
constituents contained in the two proposed wastes are presented in the
table below.\46\
---------------------------------------------------------------------------
\46\ We are considering an alternative proposal not to list
paint manufacturing waste liquids (see Section IV.D). If we do not
list wastes under K180, then there would be no need to promulgate
adjusted RQs for the following constituents: n-butyl alcohol,
methylene chloride, formaldehyde, ethylbenzene, styrene, toluene,
and xylene.
Table VIII.C-1.--Proposed RQs for Constituents Identified in K179 and
K180 Wastes
------------------------------------------------------------------------
Constituent RQ
Constituents in K179 & K180 waste streams (lbs.) (40
CFR 302.4)
------------------------------------------------------------------------
Acrylonitrile........................................... 100
Acrylamide.............................................. 5000
Antimony................................................ 5000
N-butyl alcohol......................................... 5000
Methylene chloride (dichloromethane).................... 1000
Formaldehyde............................................ 100
Ethylbenzene............................................ 1000
Methyl isobutyl ketone.................................. 5000
Methyl methacrylate..................................... 1000
Styrene................................................. 1000
Toluene................................................. 1000
Xylene.................................................. 1000
------------------------------------------------------------------------
D. How Would a Concentration-Based Hazardous Waste Listing Approach
Relate to My Reporting Obligations Under CERCLA? When Would I Need To
Report a Release of These Wastes Under CERCLA?
Today's proposed hazardous waste listings are based on the
concentrations of the hazardous constituents in the wastes. Adjusted
RQs of 100 pounds are being proposed for these wastes based on the
lowest RQ of the hazardous constituents in the wastes. Notification is
required under CERCLA when wastes meeting the listing descriptions are
released into the environment in a quantity that equals or exceeds the
RQ for the waste.
For CERCLA reporting purposes, the Clean Water Act mixture rule (40
CFR 302.6) applies to releases of these wastes when the quantity (or
concentrations) of all of the hazardous constituents in the waste are
known. In such a case, notification is required where an amount of
waste is released that contains an RQ or more of any hazardous
substance contained in the waste. When the quantity (or concentration)
of one or more of the hazardous constituents is not known, notification
is required when the quantity of waste released equals or exceeds the
RQ for the waste stream.
Although today's proposed hazardous waste listings are based on the
concentrations of the hazardous constituents in the wastes, the Agency
recognizes that it may not be necessary for a generator of these wastes
to learn the concentrations of every hazardous constituent in the
wastes in order to determine whether one of the listing descriptions
applies. This is because a waste stream need exceed only one of the
constituent-specific regulatory levels to meet one of the listing
descriptions. Moreover, many generators, after testing their waste
streams initially, may use knowledge of the waste, or of the process
generating the waste, to determine that their waste is or is not
hazardous under 40 CFR 262.11. Today's proposed rule requires sampling
and analysis only for large-volume generators of the proposed waste
streams. Therefore, many smaller generators may not know the
concentrations of the constituents in their wastes. For these reasons,
EPA believes that many, if not a majority, of the generators of these
wastes may not know the concentrations of every constituent in these
wastes, and may not, therefore, be able to apply the mixture rule.
E. How Would I Report a Release?
To report a release of proposed K179 or K180 (or any other CERCLA
hazardous substance) that equals or exceeds its RQ, you would need to
immediately notify the National Response Center (NRC) as soon as you
have knowledge of that release. The toll-free telephone number of the
NRC is 1-800-424-8802; in the Washington, DC, metropolitan area, the
number is (202) 267-2675.
You could also need to notify State and local authorities. The
Emergency Planning and Community Right-to-Know Act (EPCRA) requires
that owners and operators of certain facilities report releases of
CERCLA hazardous substances and EPCRA extremely hazardous substances
(see list in 40 CFR part 355, appendix A) to State and local
authorities. After the release of an RQ or more of any of those
substances, you must report immediately to the community emergency
coordinator of the local emergency planning committee for any 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.
F. What Is the Statutory Authority for This Program?
Section 101(14) of CERCLA defines the term hazardous substance by
referring to substances listed under several other environmental
statutes, as well as those substances that EPA designates as hazardous
under CERCLA section 102(a). In particular, CERCLA section 101(14)(C)
defines the term hazardous substance to include ``any hazardous waste
having the characteristics identified under or listed pursuant to
section 3001 of the Solid Waste Disposal Act.'' CERCLA section 102(a)
gives EPA authority to establish RQs for CERCLA hazardous substances.
CERCLA section 103(a) requires any person in charge of a vessel or
facility that releases a CERCLA hazardous substance in an amount equal
to or greater than its RQ to report the release immediately to the
federal government. EPCRA section 304 requires owners or operators of
certain facilities to report
[[Page 10126]]
releases of CERCLA hazardous substances and EPCRA extremely hazardous
substances to State and local authorities.
G. How Can I Influence EPA's Thinking on Regulating K179 and K180 Under
CERCLA?
In developing this proposal, EPA tried to address the concerns of
all our stakeholders. Your comments will help us to improve this
proposal. We invite you to provide your views on this proposal and how
it may affect you. We also are interested in receiving any comments
that you have on the information provided in Table VIII.C-1, including
the hazardous constituents identified for proposed K179 and K180 and
the maximum observed concentrations for each constituent.
IX. Analytical And Regulatory ![[logo] US EPA](http://www.epa.gov/epafiles/images/logo_epaseal.gif){kind=logo}