Tuesday
January 14, 1986
Part III
Environmental
Protection Agency
40 CFR Part 260 et al.
Hazardous Waste Management System;
Land Disposal Restrictions; Proposed
Rule
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ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Parts 260,261,262,264, 265,
268,270, and 271
[SWH-FRL 2927-31
Hazardous Waste Management
System: Land Disposal Restrictions
AGENCY: Environmental Protection
Agency (EPA).
ACTION: Proposed rule.
SUMMARY: The Environmental Protection
Agency is today proposing a framework
for a regulatory program to implement
the congressionally mandated land
disposal prohibitions. These actions are
responsive to amendments to the
Resource Conservation and Recovery
Act (RCRA), enacted through the
Hazardous and Solid Waste
Amendments of 1984 (HSWAs) on
November 8,1984.
This action proposes procedures to
establish treatment standards for
hazardous wastes, to grant nationwide
variances from statutory effective dates,
to grant extensions of effective dates on
a case-by-case basis, and procedures by
which EPA will evaluate petitions
demonstrating that continued land
disposal is protective of human health
and the environment.
In addition. EPA is proposing
treatment standards and effective dates
for the first classes of hazardous wastes
to be evaluated under this framework:
Certain dioxin-containing hazardous
waste and solvent-containing hazardous
waste.
This proposal establishes the
framework under which all hazardous
wastes will be evaluated in accordance
with the schedule (when issued as a
* final rule) that was proposed, as
published in the Federal Register of May
31,1985 (SO FR 23250) and prohibits land
disposal of certain dioxin- or solvent-
containing wastes unless the treatment
standards are achieved. The framework
and treatment standards being proposed
today do not apply to the disposal of
hazardous wastes in underground
injection wells.
DATES: Comments on this proposed rule
should be submitted on or before March
17.1986.
Public hearings are scheduled as
follows:
1. February 4 & 5.1986, 9:00 a.m. to
4:30 p.m., Dallas. Texas.
2. February 6 & 7,1986. 9:00 a.m. to
4:30 pjn.. Washington. D.C.
3. February 10 fr 11.1988, 9:00 a.m. to
4:30 p.m., Chicago. Illinois.
The meetings may be adjourned
earlier if there are no remaining
comments. Requests to present oral
testimony must be received by 10 days
before each public hearing.
ADDRESSES: Comments on this proposed
rule should be sent to Docket Clerk,
ATTN: LDR-2. Office of Solid Waste
(WH-562). U.S. Environmental
Protection Agency, 401 M Street SW..
Washington. D.C. 20460. The public
docket is located in Rm. S-212 and is
available for viewing from 9 a.m. to 4
p.m.. Monday through Friday, excluding
legal holidays. The hearings will be held
at the following locations:
1. The Lincoln Hotel/Dallas, 5410 LBJ
Freeway, Lincoln Center Dallas, Texas
75240. (214) 934-8400 (toll free for
reservations 800-228-0808).
2. Department of Health and Human
Services, North Auditorium, 330
Independence Avenue SW.,
Washington, D.C.
3. Sheraton International at O'Hare,
6810 North Mannheim Road. Rosemont.
Illinois 60018.
A block of rooms has been reserved at
the hotels in Chicago and Dallas for the
convenience of individuals requiring
lodging. Please make reservations
directly with the hotel and refer to the
EPA hearing. The hearings will begin at
9 a.m. with registration at 8 a.m. and will
run until 4:30 p.m. unless concluded
earlier. Anyone wishing to make a
statement at the hearing should notify,
in writing, Ms. Geraldine Wyer, Public
Participation Officer, Office of Solid
Waste tWH-562). Environmental
Protection Agency, 401 M Street SW..
Washington, D.C. 20460. Persons
wishing to make oral presentations must
restrict them to 15 minutes and are
encouraged to have written copies of
their complete comments for inclusion in
the official record.
To borrow (for copying) the computer
tape containing the ground water and
surface water modeling procedures
• contact: David Disney, Environmental
Research Laboratory, Environmental
Protection Agency, College Station
Road. Athens, GA. 30613. (404) 546-5432
or (404) 546-3123.
FOR FURTHER INFORMATION CONTACT:
For general information contact the
RCRA Hotline. Office of Solid Waste.
(WH-562), Environmental Protection
Agency, 401 M Street SW., Washington.
D.C. 20460. (800) 424-9346 toll-free or
(202) 382-3000.
For information on specific aspects of
this proposed rule contact: Susan
Bromm, Office of Solid Waste (WH-
562B), Environmental Protection Agency,
401 M Street SW.. Washington. D.C.
20460. (202) 382-4770.
SUPPLEMENTARY INFORMATION:
Format for Comments
Because of the complexity of the rule
that is being proposed today, and
because of the deadline of November 8.
1986, for a final rulemaking on this
subject, the Agency is requesting that
comments on the proposed rule be
organized in a particular way. In
suggesting a format for commentors. the
Agency is not attempting to restrict the
comments to specific topics, nor restrict
the method of response, but is rather
trying to focus comments to facilitate
Agency review and analysis. This
approach will also assure that
comments are totally and adequately
considered given the tight time
constraints both on the public to
comment on this proposal and on the
Agency to develop and promulgate the
necessary regulations with statutory
timeframes.
1. Overall Approach. We would first
like comments on the overall approach
taken in preparing the proposed rule,
including: the use of screening levels:
the proposed relationships between the
screening levels", best demonstrated
achieved technology determinations.
and the petition process; and the
desirability of performing a comparative
risk assessment to compare-the risks of
land disposal with those of treatment
technologies.
2. Specific Components. In this
section, we would like comments on
specific components of the approach.
including procedures for:
—Calculating screening levels (e.g.. the
selection of the back calculation
starting points, the appropriate risk
levels for carcinogens in light of the
other model assumptions, the
assumptions and inputs to the back
calculation models, and the use of a
Monte Carlo analysis):
—Selecting and identifying best
demonstrated achievable
technologies:
—Conducting comparative risk
assessments;
—Establishing prohibition effective
dates (e.g., making capacity
determinations);
—Granting case-by-case effective date
extensions;
—Evaluating petitions demonstrating
that land disposal is protective of
human health and the environment.
3. Specific Decisions. In this section.
we would like comments on the way in
which particular determinations are
made for solvent and dioxin-containing
wastes using the framework, models and
assumptions laid out in the rulemaking
package.
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teas
4. Other. Finally, we solicit any
comments not specifically covered in the
previous groupings, including all these
requested in the various units of the
proposal preamble.
Preamble Outline
/. .Background
A. Existing Land Disposal Standard
B. Hazardous and Solid Waste Amendments
of 1984
1. Solvents and Oioxins
2. California List
3. Scheduled Wastes
4. Newly Listed Wastes
C. Applicability
1. Scope
2. Exemption for Treatment in Surface
Impoundments
3. Applicability to Wastes Resulting from
Remedial and Response Actions Taken
Under the Comprehensive Environmental
Response Compensation and Liability
Actofl980(CERCLA)
//. Summary of Today's Proposal
A. Statutory Prohibitions on Land Disposal
and Section 3004(m) Treatment
Standards
B. Regulatory and Decision-Making
Framework
. C. Treatment Standards and Effective Dates
for Solvents
1. Screening Levels/Liner Protection
Threshold
2. Best Demonstrated Achievable
Technologies
3. Proposed Section 3004(m) Treatment
Standards
4. Effective Dates
D. Treatment Standards and Effective Dates
for Dioxins
1. Screening Levels
2. Best Demonstrated Achievable
Technologies
3. Proposed Section 3004(m) Treatment '
Standards
4. Effective Dates
///. Detailed Analysis of Proposed-Regulatory
Framework •
A. Conceptual Approach to Establishing
Screening Levels
1. Back Calculation Starting Points
a. Constituents of concern.
b. Chronic v acute effects.
c. Single constituent v mixtures
d. Noncarcinogenhr constituents.
e. Carcinogenic constituents;
f. Use of existing Agency health
standards.
g. Environmental effects levels.
h. Apportionment of health limits.
i. Use of population risk in selecting
starting level.
2. Ground Water Back Calculation
Procedure
a. Introduction.. . " .
b. The HELP model.
c. Fate and transport model.
d. Model assumptions.
3. Surface Water Back Calculation
Procedure
a Introduction and objective.
b. Pathways leading to contamination of
surface water and exposure to humans
and the environment.
c. Description of scenario stages.
d. Implementation.
e. Equations describing transport and
dilution processes.
f. Advection, dispersion and chemical
transformation in stream.
4. Air Back Calculation Procedure
a. Introduction.
b. Air modeling.
c. Volatizatioh test procedure.
d. Determination of distance to potential
point of exposure.
e. Timing of air component.
B. Determination of Best Demonstrated
Achievable or Available Technologies
and Performance
1. Waste Treatability Subgroups
2. Determination of "Demonstrated"
Technologies
3. Future Criteria for "Available"
Technologies
a. Proprietary or patented processes.
b. Treatment technologies that present
greater total risks than land disposal
methods.
c. Substantial treatment.
4. Identification of "Best" Technologies
5. Dilution as Treatment
C. Comparative Risk Assessments
1. Relationship to Proposed Framework
2. Methodology
a. General approach.
b. Selection of models.
c. Discussion of methodology.
3. Decision-Making Criteria
4. Additional Regulation of Treatment
Technologies
5. Results of Initial Comparative Risk
- Analyses
D. Application of Standards
1. Leaching Procedure
2. Testing and Recordkeeping
3. Facilities Operating Under a RCRA
Permit
E. Determination of Alternative Capacity and
Ban Effective Dates
1. Ban Effective Dates
2. Regional and National Capacity
3. The Nationwide Variance and the Case-
By-Case Extension
4. Determination of Capacity Requirements
by Waste Treatability Group
5. Definition of Available Capacity
6. Definition of Alternative Treatment
Capacity
7. Definition of Alternative Recovery and
Disposal Capacity
8. Calculation of Capacity
a. Current surplus capacity.
b. Planned capacity.
9. Time to Develop Capacity and Length of
Variance
F. Case-By-Case Extensions
1. Introduction
2. Receipt of Application
3. Length of the Case-By-Case Extension
4. Demonstration Included in Applications
a. Demonstration that alternative
capacity is unavailable.
b. Demonstration that sufficient capacity
is being provided.
c. Demonstration that lack of capacity is
"beyond the control" of the applicant.
d. Demonstration of binding contractual.
commitment.
e. Waste management and capacity
during extension.
f. Certification of application.
5. Consultation With Affected States
8. Notice of Initial Determination
7. Granting of Extension Approval
8. Progress Reports and Revoking the
Extension
G. Proposed Procedures to Evaluate Petitions
Demonstrating Land Disposal to be
Protective of Human Health and the
Environment
1. Introduction
2. Performance Standard
a. "[No] migration... for as long as the
wastes remain hazardous."
b. Point of potential exposure
c. "... [T]o a reasonable degree of
certainty . . .".
d. Pathways of migration
e. Time frames
f. Consideration of artificial barriers
g. Environmental effects
h. "[Hjazardous constituents."
i. "[DJisposal unit.or injection zone."
3. Applicability of the Performance
Standard
a. Landfills, surface impoundments, and
waste piles.
b. Land treatment units.
c. Underground injection wells.
d. Other methods of land disposal.
4. Demonstration Components
a. Waste analysis.
b. Human exposure and risk assessment.
c. Site'characterization.
d. Evaluation of performance of
engineered systems.
5. Request for Comments
H. Restrictions on the Storage of Waste That
Is Prohibited from Land Disposal
IV. Unit Specific Considerations
A. Land Treatment
1. Introduction
2. Background
3. Proposed Approach for Land Treatment
4. Request for Comments and Information
V, Proposed Treatment Standards for
Hazardous Wastes Containing Solvents
A. Background
1. Summary of Congressional Mandate—
Land Disposal Restrictions of Solvents
2: Description of the Solvent Listings
B. Physical and Chemical Characteristics of
Solvents
1. Solubility
2. Vapor Pressure
C. Characterization of Solvent Wastes
1. Solvent Waste Characteristics
2. Quantity of Solvents Currently Land
Disposed
D. EPA Concerns With the Land Disposal of
Solvents
1. Adverse Health Effects
2. Solvent/Liner Interactions
a. Interactions between solvents and
flexible membrane liners (FMLs).
b. Interactions between solvents and
compacted soil liners.
3. Mobilization of Other Hazardous
Constituents
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Federal Register / VoT. 51..N&. 9 / Tuesday. January14.; 198ft-. f
4. Volatilization of Solvents from Land
Disposal Sites
5. Contamination of Soil and Ground Water
E. Screening Levels/Liner Protection
Threshold
1. Applicability of Screening Levels? •
2. Derivation of the Liner Protection
Threshold
''., Applicability of the Liner Protection
Threshold
u. Toxic solvents.
b. Ignitable solvents (FOO.T).
(•' Analysis of Treatment Technologies for
Solvents and Determination of BOAT .
I. Applicable Treatment Technologies
2. Demonstrated Treatment Technologies
a. Steam and air stripping.
b. Carbon adsorption.
c. Distillation.
d. Biological degradation.
c. Incineration.
f. Fuel substitution.
3. Available Treatment Technologies
a. Proprietary processes.
b. Analysis of relative risks.
4. Determination of BOAT and Achievable
Concentrations
a. Analysis of performance data.
b. Steam (and air) stripping.
c. Carbon adsorption."
d. Biological treatment.
e. Combinations of wastewater treatment
technologies.
f. Distillation.
g. Incineration.
h. Fuel substitution.
i. Request for comment.
C, Comparison of BOAT and Screening
Levels
H Determination of Alternative Treatment
and Recycling Capacity for Solvents and
Effective Dates
1. Summary of Volumes of Wdstes Lund
Disposal Annually
Z Required Treatment of Recycling
Capacity
it. Solvent-water mixtures-
b. Organic liquids.
c. Organic sludges nnd solids.
d. Inoganic sludges and solids.
e. CERCLA wastes.
f. Summary of capacity needs.
3. Unused Capacity of Treatment and
Recycling Facilities
a. Capacity of wastewater treatment
facilities.
b. Capacity of incinerators and distillation.
4 Comparison of Treatment and Recovery
Demand with Unused Capacity
5. Time Required to Develop Alternative
Capacity
C. Effective Date for Land Disposal
Restrictions
7. Acceptance of Applications for Case-by-
Case Extensions
17. Proposed Treatment Standards for
Diotin-Containing Waste
A, Introduction
1. Summary of Congressional Mandate-
Land Disposal Restrictions of Dioxin-
Containing Hazardous Wastes
2. Description of the Dioxin-Containing
Hazardous Waste Listing
3. Summary of Regulations Affecting Land
Disposal of Dioxin-Containing Wastes
4. Quantity of Dioxin-Containing Waste
Generated
5. EPA Concerns with Land Disposal of
Dioxin-Containing Wastes
6. Contamination of Soil. Groundwater, and
Streams
B. Screening Levels for the Constituents of
Concern in the Listed Dioxin-Containing
Wastes
C Analysis of Treatment Technologies for
Dioxin-containing Wastes and
Determination of BOAT
1. Applicable Treatment Technologies
a. Technologies under evaluation:
b. Current research:
c. Technologies in conceptual or
developmental phase:
2. Demonstrated Technologies for Dioxin-
Containing Wastes
3. Analysis of Relative Risk
4. Determination of BOAT
D. Comparison of BOAT and Screening
Levels and Establishment of Treatment
Standards
1. Comparison of BOAT and Screening
Levels
2. Treatment Standard for Dioxin-
Containing Wastes
E. Determination of Alternative Capacity and
Ban Effective Dates
1.. Required Alternative Capacity for
Dioxin-Containing Wastes
2. Treatment Disposal and Recovery
Capacity Currently Available
3. Time to Develop Capacity
• 4. Land Disposal Restriction Effective Date
F. Request for Comments
Vtt. California List
Vlll. Relationship of the Part 268 Land
Disposal Restrictions Provisions to Other
RCRA Statutory and Regulatory
Requirements
A. Relationship to Other Statutory Ban
Provisions
B. Relationship to Hazardous Waste
Identification Regulations
C. Relationship to 40 CFR.Parts 284 and 265
Standards
IV. State Authority
A. Applicability of Rules in Authorized States
B. Effect on State Authorizations
C. State Implementation
X. Implementation of the Part 268 Land
Disposal Restrictions Program
XI. Regulatory Requirements
A. Executive Order 12291
1. Cost and Economic Impact Methodology
a. Baseline population and practices.
b. Development of costs.
c. Economic impact analysis
methodology.
d. Small business impact analysis
methodology.
2. Costs and Economic Impacts
a. Total national costs and economic
impacts for all RCRA-regulated wastes.
b. Total costs and economic impacts for
solvent wastes.
c. Total costs and economic impacts for
dioxin wastes.
3. Cost Analysis of Petitions
a. Introduction.
B. Methodology. . •
c. Limitations of the analysis.
d. Results.
4. Review of Supporting Documents an*'
Request for Public Comments
a. Review of supporting documents.
b. Request for public comments.
B. Regulatory Flexibility Act
C. Paperwork Reduction Act
XII. References
XIII. List of Subjects in 40 CFR Parts 260. 261.
262. 264. 265; 268. 270. and 271
I. Background
A. Existing Land Disposal Standard
On October 21,1976, Congress
enacted the Resource Conservation and "
Recovery Act (RCRA) to protect human
health and the environment and to
conserve material and energy resources.
In Subtitle C of the Act, EPA is directed
to promulgate regulations that identify
hazardous waste and to regulate
generators and transporters of
hazardous waste and facilities that
treat, store, or disp'ose of hazardous
waste.
Since 1980, EPA has issued a number
of regulations implementing these
congressional mandates. The Agency
has listed under 40 CFR Part 261, more
than 400 wastes as hazardous wastes
and employs characteristic tests to
identify other wastes as hazardous
based upon the properties of ignitability,
corrosivity. reactivity, and the toxicity
of specific chemical constituents
identified in waste extracts (leachates).
Standards have been issued under 40
CFR Parts 262 and 263 for hazardous
waste generators and transporters,
requiring generators and transporters to
comply with, among other things, a
manifest system intended to track the
movement of hazardous wastes from
"cradle to. grave."
EPA has also promulgated extensive
regulations governing the design,
operation, and care of facilities used to
treat, store or dispose of hazardous
wastes under 40 CFR Parts 264 and 265.
Standards governing existing "interim
status" facilities prior to permitting were
promulgated on May 19,1980 under 40
CFR Part 265, requiring, among other
things, that owners or operators of land
disposal facilities install ground water
monitoring wells and conduct periodic
sampling and testing of underlying
ground water. On July 26,1982, EPA
promulgated extensive permitting
standards applicable to new and
existing hazardous waste treatment,
storage, and disposal facilities under 40
CFR Part 264. These standards require,
among other things, that owners and
operators of land disposal facilities
monitor ground water and, if
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Federal Rejiatef /.Vol. 51. No. 9 / Tuesday. January 14, 1986 / Proposed Rules 1605
comtamination from the facility, is
detected, conduct corrective action. In
addition, a number of engineered
controls are required such as run-on and
runoff controls and caps at facility
closure. New units and expansions,of
existing units'are required to have liners
and leachate collection systems. Liners
must exhibit the necessary properties of
strength, thickness, and waste
compatibility to prevent system failure
or migration of contaminants through
the liner. The leachate collection and
removal system must also be able to
withstand chemical attack from the
waste or leachate. Requirements also
apply to closure of units and the post-
closure care period. Financial
assurances are required to ensure that
adequate resources are available to
meet the requirements for closure and
post-closure care.
In addition to these regulations, EPA
has also restricted the land disposal of
certain hazardous wastes. Previously
issued restrictions dealt with two broad
classes of problems: (1) Fires,
explosions, production of toxic fumes,
and similar problems resulting from
improper management of ignitable,
reactive, and incompatible wastes; and
(2) contamination of surface and ground
waters. The-Agency has promulgated
requirements specifically designed to
prevent these problems (see, for
example, 40 CFR 264.312, 265.312,
264.313, 265.313, 264.314, and 265.314) by
conditionally restricting the land
disposal of ignitable, reactive,
incompatible, and liquid wastes. For
example, ignitable and reactive wastes
may not be placed in a land disposal
facility: (i) Unless the waste is treated,
rendered, or mixed before or
immediately after placement so that the
resulting waste, mixture, or dissolution
of material no longer meets the
definition of reactive or ignitable or (ii)
under § 264.312, for ignitable wastes in
landfills, unless containerized and
protected from materials or conditions
that might cause them to ignite.
Incompatible wastes may not be placed
in the same land disposal unit unless
precautions are taken to preveat
reactions that threaten human health
and the environment under § 264.313.
Regulations in effect prior to HSWA
also conditionally restricted the disposal
of bulk, non-containerized and
containerized Kquid waste, or waste
containing free liquids in landfills. These
regulations provided that the landfill
disposal of bulk liquid wate would be
prohibited unless the unit had a liner
and leachate collection/removal system.
These.regulations also provided that
bulk liquid waste could be landfilled if
treated or stabilized before disposal so
that free liquids are no longer present.
These regulations have now been
superseded by the HSWA, which bans
the placement in landfills of fauik or non-
containerized liquid hazardous waste or
free liquids contained in hazardous
waste (§ 264.314(b)). Existing regulations
under § 264.314(d) also provide that
containerized liquid waste may not be
landfilled unless all free-standing liquid
is removed or mixed with absorbent or
solidified so that free-standing liquid is'
no longer observed.
B. Hazardous and Solid Waste •
Amendments of'1984
The Hazardous and Solid Waste
Amendments of 1984 [HSWA), enacted
on November 8,1984, impose substantial
new responsibilities on those who
handle hazardous waste. In particular,
the amendments focus on the land
disposal of hazardous wastes.
Recognizing that land disposal
technology cannot guarantee perpetual
containment of all waste constituents.
Congress has added provisions designed
to minimize reliance on land disposal.
For example, as noted above, Congress
has imposed additional bans and
limitations on placement of Hquids in
landfills. Effective May 8,1985, the
direct placement of any bulk or non-
containerized liquid hazardous waste in
landfills has been prohibited. This
provision applies regardless of the
presence of liners or leachate
collection/removal systems-or the
addition of absorbents (RCRA section
3004(c)(l), 42 U.S.C. 6924{c)(l)). EPA is
directed to promulgate regulations by
February 8,1986, that minimize the
disposal in landfills of containerized
liquid hazardous waste, and minimize
the presence of free liquids in
conatinerized liquid waste. The statute
also directs that these regulations
prohibit the disposal in landfills-of
liquids that have been absorbed in
materials that biodegrade or release the
liquids when compressed (RCRA section
3004(c)(2), (42 U.S.C. 6924(c)(2)).
Effective November 8,1985, disposal of
non-hazardous liquids in landfills is
prohibited (RCRA section 3004(c)(3), 42
U.S.C. 6934(cJ(3)). Congress has also
added new technical requirements for
land disposal facilities, such as
requirements for double liners and
leachate collection systesm (RCRA
section 3004(o), (42 U.S.C. 6934(o)), and
additional corrective action
requirements (RCRA section 3004(u) and
(v), 42 U.S.C. 6934{u), and (v)).
Amendments to section 3004 of RCRA
(42 U.S.C. 6924}, specifically prohibit the
continued land disposal of hazardous
wastes beyond specified dates.
establishing a strong statutory
presumption against such land disposal.
In its enactment of HSWA, Congress
stated explicitly that "reliance on land
disposal should be minimized or
eliminated, and land disposal,
particularly landfill and surface
impoundment, should be the least
favored method for managing hazardous
wastes" (RCRA section 1002(b)(7), 42
U.S.C. 6901(b)(7}).
The amendments specify that EPA
may not find that a land disposal
method is "protective" unless a
petitioner demonstrates to the
Administrator "to a reasonable degree
of certainty, that there will be no
migration of hazardous constituents
from the disposal unit or injection zone
for as long as the wastes remain
hazardous" (RCRA section 3004 (d)(l),
(e)(l), (g)(5), 42 U.S.C. 6924 (d)(l), (e)(l),
However, wastes that meet the
treatment standards established by EPA
are not subject to land disposal
prohibitions. The statute requires EPA to
set "levels or methods of treatment, if
any, which substantially diminish the
toxicity of the waste or substantially
reduce the likelihood of migration of
hazardous constituents from the waste
so that short-term and long-term threats
to human health and the environment
are minimized" (RCRA section- 3004fm),
42 U.S.C. 6924{m)). In setting treatment
standards for a waste, whether it is a
listed or characteristic waste, EPA may
subdivide the waste and impose .
different standards on the subdivided
wastes. Thus, for example, for a specific
waste code (e.g., F001, D002, etc.), EPA
may set more than one treatment
standard based on factors such as the
physical form of the waste.
Land disposal prohibitions are
effective immediately upon
promulgation unless the Agency sets
another effective date 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 (h)(2), 42 U.S.C.
6924(h)(2)}. EPA may also establish
different effective dates for different
physical or chemical forms.of a waste.
(Vol. 130 Cong. Rec. S13818, (daily ed.
Oct. 5, 1984)). However, these effective
date variances may not exceed 2 years
beyond the applicable statutory
deadline.
In addition, two 1-year case-by-case
extensions may be granted when an
applicant demonstrates to the
Administrator that there is a binding
contractual commitment to construct or
otherwise provide alternative capacity
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but. due to circmnstz
control of the applicant; suefe afternative
capacity cannot reasonably be made
available by the effective date (RCRA
section 3004{hH3), 42U.SX1 mztQWV.
ror the purposes of the land disposal
restrictions program, the legislation
specifically defines land disposal to
include, but not be limited to, any
placement oif hazardous waste in a
landfill, surface impoundment, waste
pile, injection well land treatment
facility, salt dome or salt bed formation.
or underground mine or cave (RCRA
section 3004(k). 42 UAC. 6fl24(k)).
Congress has also prohibited me
storage of any hazardous waste that is
subject to a prohibition from one or
more methods of land disposal unless
"such storage is solely for the purpose of
the accumulation of such quantities of
hazardous waste as are necessary to
facilitate proper recovery, treatment or
dispoeal" (RCRA section 3004(jL 42
U.aC. 89240)). The legislative history
accompanying this provision indicates
that "the purpose of this ameolnient is
to avoid the potential problem of waste
generators, handlers, or disposers
utilizing 'sham' storage to avoid a
prohibition on the disposal of a
particular waste froia one or more
methods of disposal" (VoL 129 Coag.
J*ea H8139 (daily ed. Oct 6,1B83).
section-by-section analysis of Breaux
amendment). This provision is discussed
in more detail in Unit IILH of this
preamble.
Congress has also provided a
conditional exemption from land
disposal prohibitions for the treatment
of wastes in a surface impoundment;
provided that treatment residues that
are hazardous are removed within one
year of the entry of the waste into the
impoundment (RCRA section
3005(j)(ll)(B), 42 U.S.C. 692SO)(11J[B3). In
addition, section 3005(j)(ll)(A) requires
that such impoundments meet certain
technological requirements, subject only
to limited exemptions. This provision is
discussed in more detail in Unit I.C.2 of
this preamble.
The legislation sets forihi series of
deadlines for Agency action. At certain
deadlines, further land disposal of a
particular group of hazardous wastes is
prohibited unless the Agency has set a
treatment standard that rnininrizes
threats to human health and the
environment. In such cases, if EPA has
not established treatment standards by
the applicable statutory date, land
disposal of the affected wastes will be
allowed only if the Agency finds that a
case-specific petition successfully -
demonstrates that there will be no
migration of hazardous constituents
frc n a disposal unit for as tong as the
waste remains hazardous. Other
deadfines cause conditional restrictions
on land disposal to take effect if
treatment standards have not been
promulgated. However, in any case
where EPA does not set a treatment
standard for a waste by the statutory
date, it is not precluded from later
promulgating a treatment standard for
that waste. Likewise, where EPA has set
a treatment standard, it is not precluded
from revising that standard after the
statutory date through rulemaking
procedures. The relevant statutory
deadlines are explained ia detail in the
following units.
1. Solvents and Dioxins
Effective November 8.1988, the
statute prohibits further disposal (except
with respect to underground injection
into deep injection wells) for the
following wastes:
Dioxin-contalning hazardous wastes
numbered F020, F021. F022. PD23, F028,
F027. and F028 l and solvent-containing
hazardous wastes numbered F001. FOQ2,
F003. F004. and F005. (RCRA 3004 (e)(l),
(e)(2). 42 U.S.C. 6824 (e)(l). (e)(2M
If EPA fails to set treatment standards
for solvents and dioxins by the statutory
deadline such wastes are prohibited
from land disposal (other than in
injection wells, where the applicable
statutory deadline is August 8,1986),
other than those wastes and sites for
which a petitioner has successfully
demonstrated that land disposal is
protective of human health and the
environment
2. California List
. Effective July 8,1967 (32 months from
November 8,1984), the statute prohibits
disposal (except with respect to
underground injection into deep
injection wells) for the following wastes,
listed or identified under section 30012:
a. Liquid hazardous wastes, including
free liquids aannHated with any solid or
sludge, containing free cyanides at
concentrations greater than or equal to
1.000 mg/L
b. Liquid hazardous wastes, including
free liquid* associated wife any solid or
sludge, containing the following metals
(or elements) or compounds of these
metals (or elements) of concentrations
1 AxiucwMd in Unk VLA.1, lh* finaldioxin
ruiemaluag (SI FK1S7B. Inaary 14.3978) added
three more wa»le codei F02a fD27 sad F02aThe
additional waste codes aie a lasult of a
reorganization and do not represent a substantive
departure from the proposed rtde. .
1 Thit !*.<• baud oa regntoioa. developed by
the California Department of Heal* Services far
hazardous waste l«nd disposal restrictions in the
state of California. Thus it has become known as
the "California List."
greater than or equal to those specified
below:
i. Arsenic and/or compounds (as As)
500mg/I;
ii. Cadmium and/or compounds (as
Cd} 100 mg/k
iii. Chromium (VI and/or compounds
(as Cr VI)) 500 mg/1;
iv. Lead and/or compounds (as Pb)
500 mg/1;
v. Mercury and/or compounds (as Ha)
20 mg/h
vi. Nickel and/or compounds (as Ntt
134 mg/t;
vii. Selenium and/or compounds fas
Se) 100 mg/1;
viii. Thallium and/or compounds fas
Th) 130 mg/1.
c. Liquid hazardous wastes having a
pH less than or equal to 2.0.
d. Liquid hazardous wastes containing
polychlorinated biphenyls (PCBs) at
concentrations greater than or equal to
50 ppm.
e. Hazardous wastes containing
hatogenated organte compounds in total
concentration greater than or equal to
1,800 mg/kg. (RCRA section 3G04(dXl}
and (2). 42 U.S.C. 8924(d) (1) and t2)}.
If EPA fan's to set treatment standards
for the Cafifemta List by July 8,1987,
such wastes are prohibited from land
disposal at the levels indicated (other
than in injection wells, where the
applicable statutory deadline is August
8,1988), other than for those wastes and
sites for which a petitioner has
successfully demonstrated that land
disposal is protectire of human health
and the environment.
During the period ending November 8,
1968 (48 months from November 8,1984),
disposal of contaminated soil or debris
resulting from a response action taken
under section 104 or M8 of the
Comprehensive Environmental
Response, Compensation, and Liability
Act of IflTO (CERCLA) (Superftmd), or a
corrective action required under RCRA.
is not subject to any land disposal
prohibition or treatment standard for
solvent- and dioxin-containing wastes
and wastes covered by the California
List. (RCRA section 3004 (d){3), (e)(3), 42
U.S.C. 8924 (dtf3). (eK3)).
Decisions on disposal restrictions for
deep well injection of dioxin-containing
hazardous wastes, solvent-containing
hazardous wastes, and California List
wastes rmwt be made no later titan
August 8,1988 (45 months from'
enactment). (RCRA section 3004(fJ, 42
U.S.C; 6924(f)5.
3. Scheduled Wastes
Section 3004(g) of RCRA (42 U.S.C.
6924(gJ) also.requires the Agency to set
a schedule for making land disposal
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tear
restriction decisions for all hazardous
wastes listed, as of November 8,1984,
under section 3001 which are not
referred to under the Units I.B. 1 and 2
headings, "Solvents and Dioxins" and
"California List." EPA is required to
submit this schedule to Congress by
November 8,1986.
Section 3004{g)(2) (42 U.S.C.
6924(g)(2)) requires that the schedule be
based on a ranking of the listed
hazardous wastes which considers their
intrinsic hazards and their volume such
that decisions regarding the land
disposal of high volume hazardous
wastes with high intrinsic hazard shall
be scheduled first and low volume
wastes with lower intrinsic hazard shall
be scheduled last.
Section 3004(g)(4) (42 U.S.C.
6924{g)(4)) requires EPA to make
determinations on land disposal
prohibitions within the following time
frames:
a. At least one-third of all ranked
hazardous wastes by August 8,1988 (45
months from November 8,1984).
b. At least two-thirds of all ranked
hazardous wastes by June 8,1989 (55
months from November 8,1984).
c. For all remaining ranked hazardous
wastes and for all hazardous wastes
identified by characteristic under
section 3001 by May 8,1990 (66 months
from November 8,1984).
EPA issued the proposed schedule, as
published in the Federal Register of May
31, 1985 (50 FR 23250), and expects to
issue it .as a final rule prior to November
8,1986.
If EPA fails to set treatment standards
by the statutory deadline for any
hazardous waste in the first-third or
second-third of the schedule, such
hazardous wastes may be disposed in a
landfill or surface impoundment only if
the facility is in compliance with the
technology requirements set forth in
section 3004(o) of RCRA (42 U.S.C.
6924(o)).3 Moreover, prior to disposal,
the generator must certify to the
Administrator that he has investigated
the availability of treatment capacity
and has determined; that the use of such
landfill or surface impoundment is the
only practical alternative to treatment
currently available to him. These
conditions apply until EPA promulgates
regulations establishing treatment
standards for the waste concerned. If
EPA fails to set treatment standards for
any of the scheduled listed wastes by
May 8,1990, all such wastes are
prohibited from land disposal unless
EPA grants a case-by-case petition.4
4. Newly Listed Wastes
The land disposal prohibitions apply
to all hazardous wastes identified or
listed under section 3001 as of the date
of enactment of the HSWA. EPA is
required to make land disposal
prohibition determinations for any
hazardous waste identified, or listed
under section 3001 after November 8,
1984, within 8 months of. the date of
identification or listing (RCRA section
3004(g)(4), 42 U.S.C. 6924(g)(4)). The
statute does not impose an automatic
prohibition if EPA misses a deadline for
any newly listed or identified waste.
C. Applicability
1. Scope
Pursuant to section 3004(k) of RCRA,
land disposal is defined (for purposes of
the land disposal restrictions regulatory
program) as including, but not being
limited to, any placement of hazardous
waste in landfill, surface impoundment,
waste pile, injection weil, land
treatment facility, salt dome formation,
salt bed formation, or underground mine
or cave. Under this statutory definition,
waste management techniques
considered as storage or treatment are
subject to restriction if they involve
placement of hazardous waste in or on
the land. Thus, the restrictions program
applies to units such as "storage" waste
piles (including enclosed waste piles),
and "storage" or "storage and
treatment" surface impoundments. (The
legislation does provide a conditional
exemption for treatment in surface
impoundments, see discussion in Unit
I.C.2.) The definition of land disposal is
not being limited to placement in the
types of units specifically identified in
section 3004(k). EPA is proposing
specifically to include open detonation
and placement in concrete vaults or
bunkers intended for disposal purposes
as methods of waste management
subject to land disposal restrictions.
This interpretation is consistent with
EPA's existing policy to consider such
practices as storage or disposal in the
land and is also consistent with the
overall intent of Congress in enacting
this provision.
3 In this situation, placement of such wastes in
other types of land disposal units (e.g.. deep
injection wells), would not be precluded by
operation of 3004(g)(6)). See Vol. 130 Cong. Rec.
S9192 (daily ed July 29.1984).
4 An automatic prohibition is not imposed for
hazardous wastes "identified" under section 3001 if
EPA misses the May 8,1990. deadline for setting
treatment standards. "Identified" wastes are wastes
defined as hazardous because they meet ene or
more of the general hazardous characteristic tests in
40 CFR 261.21 through 261.24..rather than wastes
"listed" as hazardous in 40 CFR 261.30 through
Z61.33 because they contain one or. more specified
hazardous constituents. For further discussion of
this point, see 50 FR 23252.
The Agency interprets the restrictions
on land disposal to apply prospectively,
that is, to placement of hazardous
wastes in or on the-land after the
effective date of a restriction. Thus,
wastes placed in land disposal units
prior to the effective date of a restriction
do not have to be removed or exhumed
for treatment. Similarly, the Agency
interprets the restrictions on storage of
prohibited wastes to apply
prospectively, i.e;, storage restrictions
apply only to wastes placed in storage
after the effective date of an applicable
land disposal restriction. However, if
wastes are removed from either storage
or a land disposal unit, subsequent
placement in or on the land after an
applicable effective date would be
subject to restriction and treatment
requirements. For example, hazardous
wastes that were placed in storage in an
impoundment or waste pile prior to an
applicable effective date that are later
removed generally would be banned
from subsequent land disposal after the
effective date unless the wastes met
applicable treatment standards or were
the subject of a successful petition.
Likewise, waste placed in storage in a
tank or container prior to an applicable
effective date must meet applicable
treatment standards or be the subject of
a successful petition before any
subsequent land disposal after the
effective date. •
The regulatory framework and
resultant section 3004(m) treatment
standards proposed today do not apply
to the disposal of hazardous wastes
through underground injection wells.
Although injection wells are included in
the statutory definition of land disposal.
Congress established later deadlines
and, for some wastes, employed
different language, in directing EPA to
restrict hazardous wastes from disposal
through underground injection wells.
Therefore, § 268.1(c) exempts disposal of
hazardous wastes in injection wells
from the requirements being proposed
today. The Agency's plan for addressing
restrictions on the disposal of hazardous
waste in deep injection wells will be
addressed in a later notice.
Under today's proposal, the
conditional exemption from the
requirements of Parts 262 through 265 for
hazardous waste from small quantity
generators (see 261.5) would be
extended to include these proposed Part
268 requirements. Under existing 261.5, a
small quantity generator is one who
generates less than 1000 kg of hazardous
waste in a calendar month. The
conditions of exemption from the
requirements of Parts 262 through 265
vary according to the generator's
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1808
IW«rai
geoeratlmaad accamMiatkjsi rates aad
also vary depending upon whether or
not the generated waste is aa acutely
hazardous •waste.
[Note—Acutely hazardous waste are
subject Jo full regulation when generated or
accumulated in quantities a« little as 1 kg.J
On August 1.1985, the Agency
proposed to redefine, in 261.5. a small
quantity generator as one who generates
less than 100 kg of hazardous waste in a
calendar month. In so doing, the Agency
proposed to remove hazardous waste
from generators of greater than 100kg
but less than 1000 kg in a calendar
month from the conditional exemption
from the requirements of Parts 262
through 265 contained in existing 261.5.
If. in the final rule, the Agency
promulgates the August 1.1985,
proposed redefinition of small quantity
generator, hazardous waste from
generators of between 100-1000 kg/
month will become subject to the Part
268 requirements contained in today's
proposal.
2. Exemption for Treatment in Surface
Impoundments
The land disposal restrictions arrived
at through the regulatory framework
proposed today do not apply to wastes
that are treated in surface
impoundments under certain conditions
as indicated hi § 286.1(e). Section
3005(i)(ll)(B) provides that a waste that
would otherwise be prohibited from one
or more methods of land disposal
nevertheless may be treated in a surface
impoundment as long as treatment
residues that are hazardous are removed
within 1 year of the entry of me waste
into the surface impoundment. EPA
interprets this provision to apply to both
permitted and interim status surface
impoundments used for the treatment of
wastes.
This provision does not apply to
wastes that have already been
pretreated m accordance with
requirements established tinder section
3004{m) or exempted from-the ban
through the petition process. Soch
was.tes would no longer beconsidered
"prohibited" wastes and. accordingly.
may be given additional treatment in a
surface impoundment without complying
with the restrictions imposed by section
3005(JH11)(B). EPA believes that this
interpretation of sabparagraph (B) is the
only interpretation that is consistent
with the language of sections 3004 and
3005 and with the legislative history to
section 3005(|Ktl). The Agency
considered whether sabparagraph (B)
nould be construed to apply additional
requirements to wastes that have
already been treated by methods or to
levels required aader section am^n).
However, •action 3«M(ni)(Z} provides
that a waste which has been treated in
accordance with section 3004(m) is no
longer prohibited from land disposal.5
Therefore, such a waste cannot be
deemed to be a "hazardous waste which
is prohibited" under section
3005(JJ(11KB).
EPA also considered whether section
3005(JKn)(B) could be construed to
apply to surface impoundments that
accept hazardous wastes that have been
determined to be protective of human
health and the environment when land
disposal in accordance with a petition
demonstration pursuant to section 3004
(d), (e), or (g). However, like a waste
treated under section 3004(ai). a waste
for which a successful petition
demonstration has been made is no
longer prohibited from land disposal and
therefore could be given additional
treatment ia the surface impoundment
without complying with the restrictions
imposed by section 3005{j){ll){B).«
Section 3G05(JH11«B) applies to
wastes that are banned from aay
method of land disposal, not just
disposal in surface impoundments. Thus,
if EPA were to ban a waste from
disposal in landfills, but not surface
impoundments, that waste nevertheless
would be prohibited from treatment in a
surface impoundment unless die
treatment residues that are hazardous
were removed within 1 year as required
by the statute..
EPA does not construe the language of
section 3G05(j}{llXB) requiring removal
of "treatment residues which are
hazardous" to mean that such residues
must be delisted in order to avoid the
removal requirement Rather, the
Agency interprets the term "residMes
which are hazardous" in this context to
refer to any fraction* of a waste (liquid.
semi-solid, or solid) that do not meet
treatment standards established under
section 30Q4(fli) or that have not been
exempted from the baa through the
petition process. The Agency interprets
"subsequent management" as waste
management other than in aa
impoundment. EPA believes that
Congress did not intend for
subparagraph (B) to authorize the
perpetual management of prohibited
wastes in surface impoundments.
5 Section 3004(mK2) states thai "tf.'. . hazardous
waste has been treated to the levd or by a method
specified in relations ander this nutwectiwn, sock
waste or residue thereof »hal! no* be sstyect to any
prohibition promatgated wider Mtoection (d). (e),
(f). or (g)."
B Section 3004 fd). (e). and (j) provide that if the
Administrator accepts a petition demonstration for
a waste, he has determined that "the prohibition on
. . . land disposal of such was!* is not required."
Section 3005{jXll)(B) does «<* appear
to reaaire that treatment impoundments
necessarily be drained in order to
remove treatment residues. This
interpretation is supported by the
following quote from the legislative
'history of the amendments:
Section 3Q05())(nKBJ "does not apply to
those wastes which have been subject to the
pretreatment of [sicj detoxification
requirements established by the
administrator tinder section 3004(m).
Removal of hazardous treatment residues
does not necessarily require complete-
drainage of the impoundment and in
appropriate case* caa be carried out by
vacuum or mechanical devices which remove
concentrated bottom sludges." (VoL 130
Cong. Rec. S13815 [daily ed. October 5,1984).)
In the case where the hazardous
"residue" is a supernatant liquid, that
residue may be removed by pumping.
The two general methods available for
removing residues with a lower water
content are excavation and dredging.
The technique used depends upon such
variables as surface impoundment
design characteristics (e.g., shape,
surface area, depth, presence of Hser,
type of liner), waste characteristics
(quantity and type), and accessibility of
the impoundment
Excavation is sometimes used to
remove solids, thickened sludges, and
other materials that have a low water
content. Excavations may be performed
using draglines, backhoes. or bulldozers.
Excavation techniques are generalry
more appropriate for small
impoundments; and, for some methods,
the impoundment must be drained.
Excavation is generally more useful for
non-acutely hazardous and less aqueous
sludges. Some of the excavation
methods may pose a greater risk of
damaging liners during the removal
process than some of the dredging
techniques.
Dredging techniques are more
commonly used for removal of residues
with a higher water content (e.g., liquid.
slurry, or semi-solid). These techniques
are generally appropriate for all sizes of
surface impoundments and can be
employed without interrupting the
operation of the facility.
Both mechanical and hydraulic
dredging techniques are available.
Mechanical dredging equipment
includes grapple, dipper, and bucket
dredges. Grapple dredges are most
suitable for removing medium-soft
materials. The bucket dredge is an
efficient mechanical dredge that
employs a continuous work cycle.
Hydraulic dredging includes plain
suction and cutterhead pipeline
dredging. The former is typically used to
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/ Tfces&y^ January 14, 1986, / Proposed Rides
1B09
remove soft, free-flawing materials. The
cutterhead pipeline dredge is a versatile
machine widely used for removing
waterbound solids of all types.
In determining the appropriate
removal technique, the benefit
associated with removing the hazardous
residues (i.e., reducing the danger of the
waste permeating, corroding, or cracking
the liner) must be weighed against the
risk of damaging the liner during the
removal process. Both compacted clay
and synthetic liners are susceptible to
damage during dredging or excavation
operations. Hydraulic dredging
equipment may be less likely to damage
liners than dragline dredges (Ref. 60).
EPA is aware that there are additional
risks associated with the removal
process in the handling and
transportation of the hazardous
residues. The Agency may issue
regulations or guidance at a later date
regarding removal requirements such as
testing for liner damage after removal of
the residues and prohibiting certain
types of removal methods. EPA solicits
comment on the removal techniques
available and the environmental risks
associated with the use of these
methods.
Section 3005(j)(ll)(A) also addresses
wastes subject to the restrictions
program. Subparagraph (A) provides
that if the Administrator "allows" a
hazardous waste that is prohibited to be
placed in a surface impoundment for
storage or treatment, such impoundment
must meet the liner and leachate
collection system requirements imposed
by section 3004{o)(l) unless the
impoundment qualifies for certain
exemptions. Because the only instance
in which a prohibited waste is allowed
to be placed in a surface impoundment
is in accordance with subparagraph (B),
EPA construes subparagraph (A) to
impose additional requirements on
impoundments that are used to treat
prohibited wastes under subparagraph
(B). Accordingly, EPA construes this
provision to impose an additional
condition on the placement of hazardous
wastes in surface impoundments under
subparagraph (B), i.e., such wastes may
not be treated in a surface impoundment
unless the impoundment meets section
3004(o)(l) standards. The legislative
history to the amendment that added
subparagraph (j)(ll)(A) to section 3005
confirms that the purpose of the
provision was "not to carve out an
exemption to the land disposal
restrictions... but rather to set
minimum standards for surface
impoundments which the Administrator
allows to continue receiving a *
prohibited waste." (Vol. 129 Cong. Rec.
H8140 (daily ed. October 8,19837
(section-by-section analysis of Breaux
amendment).) Thus, unlike
subparagraph (B), this provision does
not provide a separate exemption from
land disposal restrictions.
One apparent problem in interpreting
section 3005(j)(ll)(A] as applying to
impoundments exempted under section
3005(JKll)(B) is that subparagraph (A)
refers to placement in an impoundment
for storage or treatment, while
subparagraph (B) refers only to
treatment in a surface impoundment
EPA believes that by using the term
"storage," Congress acknowledged that
under the existing RCRA regulatory
program, treatment in a surface
impoundment always occurs in the
context of either storage (the temporary
holding of hazardous waste) or disposal
(the permanent holding of waste at a
facility). See 48 FR 2808 (January 12,
1981).
Subparagraph (A) contains a
parenthetical reference stating that it
applies to interim status units. This
provision would appear to impose more
stringent requirements on interim status
units than on permitted units. Such a
construction runs counter to the general
structure of EPA regulations, which
provide that permitting requirements be
at least as stringent as, if not more
stringent than, interim status
requirements. Thus, despite the explicit
reference to interim status units in
subparagraph (A), EPA construes
subparagraph (A) to apply to both
permitted and interim status surface
impoundments. This reading is
supported by both EPA's current
regulatory structure, as noted
previously, and by the legislative
history. The amendment that added
subparagraph. (A) to the legislation also
contained retrofitting requirments that
were more stringent than the
requirements that were finally enacted.
See Vol. 129 Cong. Rec. H8136 (daily ed.
October 8,1983). Under the original
version of the amendment, any permit
issued for a surface impoundment would
have required compliance with the
minimum technological requirements.
All interim status surface impoundments
would have been required to be
permitted within 4 years. Because all
permitted units would have had to '
comply with the new liner standards,
subparagraph (A) needed to cover only
interim status units. Thus, in interpreting
subparagraph (A) to apply to both
permitted and interim status
impoundments EPA believes that it will
carry out the purposes of the original
amendment, which in effect would have
provided that all prohibited wastes
would go to surface impoundments' in
compliance with the new liner standards
or with specified exemptions.
Section 3005(j)(ll)(A) mandates
compliance with requirements
applicable to new surface
impoundments under section 3004(o)(l)
unless the requirements of section
3005(j) (2) or (41 are met. Section
3005(j)(2) exempts a surface
impoundment from liner and leachate
collection system requirements if the "
impoundment haa at least one liner that
is not leaking, is located more than one-
quarter mile from an underground
source of drinking water and is in
compliance with certain ground water
monitoring requirements. Section
3005(j)(4) similarly exempts surface
impoundments for which it is
demonstrated that there will be no
migration of any hazardous constituent
to ground water or surface water at any
future time. However! section
3005(j)(ll)(A) does not reference two
other exemptions found in section
3005(j); J-e- paragraph fj)(3) pertaining to
certain wastewater treatment units, and
paragraph (j)(13) pertaining to certain
impoundments subject to collective
action requirements. Accordingly, an
impoundment that is otherwise exempt
from the minimum technological
requirements under paragraphs (j) (3) or
(13) nonetheless would be prohibited
from treating restricted wastes under
section 3005(j)(ll)(B}, unless, it meets the
requirements of section 3004(o).
3. Applicability to Wastes Resulting
From Remedial and Response Actions
Taken Under the Comprehensive
Environmental Response Compensation
and Liability Act of 1980 (CERCLA)
Wastes resulting from remedial and
response actions taken under sections
104 and 106 of CERCLA, when disposed
of off-site, are managed at facilities in
compliance with all applicable RCRA
Subtitle C requirements. When land
disposal restrictions go into effect, such
facilities may not land dispose
hazardous wastes subject to such
restrictions unless applicable treatment
standards are met, or a successful
petition demonstration has-been made.
Accordingly, CERCLA wastes subject to
land disposal restrictions and disposed
of off-site must meet applicable
treatment standards or be the subject of
a successful petition demonstration
prior to being land disposed at a RCRA
Subtitle C facility. However, RCRA
section 3004(d)(3) does provide a limited
exception for certain CERCLA wastes.
Contaminated soil and debris that
would otherwise be subject to land
disposal restriction under section
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Federal Regiater / :VeI. -51, No.-
3004{e) (i.e., an FOd through F005
solvent-containing^wasteor, an F021
through F023, F026 or FG27 dioxin-
containing waste) or section 3004(d) {i.e.
a 'California List" waste) can
nevertheless be land disposed until
November 8,1988.
The CERCLA program will comply
with the land disposal restrictions
program in managing Superfund waste
taken off-site. To the extent that the
land disposal restrictions program is
applicable or relevant and appropriate
to the management of Superfund wastes
on-site, the Superfund program will
comply with the land disposal
restrictions program in a manner that is
consistent with the National
Contingency Plan (50 FR 47912) and the
compliance with other environmental
statutes policy (50 FR 47946) contained
in the preamble, published in the
Federal Register on Wednesday,
November 20,1985.
II. Summary of Today's Proposal
EPA today is proposing and
requesting public comment on a
framework for a regulatory program to
implement the land disposal
prohibitions mandated by Congress
under section 3004 (d). (e). and (g). EPA
is also proposing the section 3004(m)
, treatment standard and associated
effective dates for two classes of
hazardous wastes: Solvent wastes and
dioxin-containing wastes addressed by
section 3004(e). (Unless otherwise
specifically noted or contextually
obvious, "treatment standards" in this
preamble refers to RCRA section
3004(m) standards.) EPA used the
decision-making framework described in
today's proposal to develop these initial
sets of proposed treatment standards
and associated effective dates. The
Agency hopes that its simultaneous
proposal of the land disposal
restrictions program framework and the-
initial treatment standards derived
therefrom will assist the public in
understanding the program's mechanics
and its environmental and economic
impacts, and serve to focus public
comment It may be desirable in the
final rule, however, to separate-the
decision-making framework from the
standards for solvent- and dioxin-
containing wastes and issue them as
two separate rulemaldngs.
This unit of the preamble provides a
brief summary of the major program
components and describes'how they are
integrated into a regulatory framework..-
Unit III. following, describes
individually, and in greater detail, the
development and,implementation of
each of these components, including
descriptions of the various models used
by EPA in implementing'the program.
Detailed mathematical descriptions of
these models are provided in this
preamble and in background documents
available for public examination in the
RCRA docket (see ADDRESSES). The
proposed treatment standards and
associated effective dates derived from
this regulatory framework for the initial
two classes of hazardous wastes are
then presented in Units V and VI.
A. Statutory Prohibitions on Land
Disposal and Section 3004(m) Treatment
Standards-
Section 3004 (d). (e). and (g)
automatically prohibits continued land
disposal of all listed hazardous wastes
beyond specified dates. Each of these
subsections, however, provides
exceptions to the prohibitions for wastes
and treatment residuals that comply
with standards to be promulgated by
EPA under section 3004(m). Section
3004(m) requires EPA to "promulgate
regulations specifying those 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 long-
term and short-term threats to human
health and the environment are
minimized.".
'In addition to providing exceptions for
wastes that comply with the treatment
standards, section 3004 (d), (e), and (g)
also allows the'Administrator to
determine that the statutory prohibition
on one or more methods of land disposal
is "not required in order to protect
human health and the environment for
as long as the waste remains
hazardous." However, the Administrator
is precluded from determining that a
method of land disposal is protective
"unless, upon application by an
interested person, it has been
demonstrated to the Administrator, to a
reasonable degree of certainty, that
there will be no migration of hazardous
constituents from the disposal unit or
injection zone for as long as the wastes
remain hazardous."
Accordingly. EPA haa two primary
responsibilities under this statutory
scheme:
1. To promulgate exceptions to the
statutory prohibitions, in the form of
treatment standards ensuring-that the
long-term, and short-term threats to
human health and the environment
arising from continued land disposal are
minimized.
2. To grant exemptions from the
statutory prohibitions, through approval
of petitions successfully demonstrating
that continued land disposal of specific
hazardous wastes is protective of
human health and the environment.
The Agency also is responsible for
establishing variances from and
extensions to the statutory effective
dates for the land disposal prohibitions.
as well as for the implementation of
statutory prohibitions on the storage of
wastes that are prohibited from land
disposal.
Before presenting and describing the
entire regulatory and decision-making
framework being proposed today, it is
necessary to discuss in greater detail
one of its central aspects: the
establishment of treatment standards.
As the following discussion explains,
EPA will determine both technology-
based levels and screening levels as
intermediate steps in establishing a
section 3004(m) treatment standard.
The objective of the treatment
standards is to minimize the threats to
ground water (due to leaching), air (due
to emissions), and surface waters (due
to leaching) associated with tend
disposal of hazardous wastes by
substantially reducing the toxicity and/
or mobility of such wastes prior to
placement in land disposal units. The
statute specifies that such standards
may take the form of prescribed levels
or methods of treatment. Treatment
standards therefore, may take the form
of performance standards governing the
nature of quality of wastes or treatment
residuals that may be.placed in land
disposal units. Such performance
standards may be expressed as
maximum acceptable concentration
levels for individual chemical
constituents in extracts from wastes
(e.g., maximum leachate
concentrations), or in the wastes
themselves (e.g., maximum waste
concentrations). The statute indicates
that treatment standard also may take
the form of specified treatment methods
or treatment chains that must be applied
to wastes prior to placement in land
disposal units (e.g.. incineration of
organics; stabilization of metals:
precipitation of metals from waste water
streams, followed by fixation of
precipitate sludges, etc.). The Agency
grefers, however, to express treatment
standards as performance standards
wherever possible because such
standards provide greater flexibility to
the regulated community in developing
and implementing compliance strategies.
Section 3004(m} specifies that
treatment standards- must "minimize"
long- and short-term threats to human
health and the environment arising from
land disposal of hazardous wastes.
« Congress indicated in the legislative
history accompanying the HSWAs that
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Tuesday, January 14, 1986 / Proposed Rule*
ItfXX
"[t]he requisite levels of [sic] methods of
treatment established by the Agency
should be the best that has been
demonstrated to be achievable", noting
that the intent is "to require utilization
of available technology" and not a
"BAT-type process which contemplates
technology-forcing standards." (Vol. 130
Cong. Rec. S9178 (daily ed., July 25,
1984).) EPA interprets this legislative
history to suggest that Congress
considered the "minimize" standard to
be met by application of this best
demonstrated achievable (or available)
technology (BDAT) prior to placement of
wastes or treatment residuals into land
disposal units. In developing technology-
based levels, treatment processes are
evaluated based upon the performance
of their residuals in the land disposal
environment.
Congress acknowledged that current
technologies may be incapable of
completely eliminating threats arising
from the land disposal of certain types
of hazardous wastes. The legislative
history notes, for example, that "for
certain wastes, such as metals and
inorganics, there are no practical
treatment technologies at this time that
. permanently eliminate their toxicity."
The legislative history specifically
suggests that state-of-the-art
stabilization techniques would meet the
section 3004(m) "minimization"
requirements for such wastes, even
though such techniques are
acknowledged to be less than
completely effective in reducing long-
term mobility of hazardous constituents.
However, the Agency does not believe
that Congress intended all state-of-the-
art technology to be deemed appropriate
treatment, regardless of its level of
performance. In noting that the
Administrator shall specify "those 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," Congress
clearly implies that a minimum
performance standard, in the form of
"substantial" reductions in toxicity and/
or mobility, must be achieved under the
section 3004[m) treatment standards.
EPA is concerned that some treatment
technologies, when applied to particular
waste streams, may result in significant
releases of hazardous constituents to the
environment in the process of achieving
"substantial" reductions in the waste's
toxicity or mobility prior to land
disposal. Depending upon their nature
and magnitude, the total risks
associated with these releases may in
fact be greater than the risks associated
with land disposal of the waste.
. ,v.' • •••:- 4_
Therefore, to ensure that total human
health and environmental risks are not
increased as a result of EPA's
implementation of the statutory land
disposal prohibitions, the Agency will
conduct risk assessments to compare
the risks of managing wastes in land
disposal units with die risks of
managing wastes in alternative
treatment technologies, including any
subsequent land disposal of treatment
residuals. Treatment technologies that
are found through these comparative
risk assessments to pose greater total
risks than those posed by direct land
disposal of the waste will be classified
as "unavailable" for purposes of
establishing the section 3004(m)
treatment standard for that waste.
These comparative risk assessments,
described in greater detail in Unit IH.C,
are not explicitly required under RCRA.
The Agency believes, however, that
Congress did not intend risks to human
health and the environment to be
increased in prohibiting the continued
land disposal of hazardous wastes. EPA
believes that it is desirable, reasonable,
and consistent with the intent of ~
Congress to include comparative risk
assessments to classify as "unavailable"
for purposes of establishing treatment
standards those waste/treatment
technology combinations that pose •
greater total risks to human health and
the environment than those posed by
direct land disposal of the waste..
However, the statute does not allow a
determination that one or more
alternative treatment'technologies pose
greater risks than land disposal of the
waste should not be used as a basis for
allowing continued land disposal of the
waste. Rather, when these comparative
risk assessments identify specific,
unacceptable risks for an alternate
treatment technology or treatment train,
EPA will endeavor to reduce these risks
through development and promulgation
of additional standards (e.g.; air
emissions controls). Unfortunately, these-
additional standards may not be
developed by the time the restrictions
take effect, thus, requiring that
technologies posing risks greater than
land disposal be considered
"unavailable" for purposes of
establishing BDAT Levels. As a result,
the universe of candidate technologies
for BDAT may be more limited. In
addition, since technologies ruled out
because of risk may be more efficient
than other candidate technologies, the
remaining technologies on which the
BDAT treatment standard is based may
allow greater concentrations of
hazardous constituents in the .residuals
going to land disposal.
The Agency may also prohibit the use
of technologies found to be riskier than
land disposal. However, these
prohibitions may not be effective prior
to the effective date of ban restrictions.
In cases where additional standards or
prohibitions for'riskier technologies are
not promulgated prior to a restriction
effective date, such technologies may be
used to meet concentration levels set
under section 3004(m) even though these
technologies did not form the bases for
selecting such levels. In an effort to
avoid this result, EPA will attempt to
regulate riskier technolgies prior to the
ban effective date whenever possible.
In addition to developing technology-
based levels, EPA will invoke the
authority of section 3004(m) to establish
screening levels. A screening level will
be developed for each individual
hazardous constituent and will identify
the maximum concentration below
which the Agency believes there is no
regulatory concern for the land disposal
program and which is protective of
human health and the environment. The
methodology used in establishing these.
levels is described in detail in Unit in.
These screening levels will serve three.
major functions.
First, the screening level, or
concentration level, will be used to
avoid "excessive" treatment, hi some
cases, available technologies may be
capable of achieving greater reductions
in toxicity and/or constituent mobility
than are actually necessary to provide
protection of human health and the
environment in subsequent land
disposal of hazardous wastes. The
Agency does not believe that Congress
intended that EPA promulgate standards
requiring treatment for treatment's sake
(i.e., requiring more treatment than
necessary to protect human health and
the environment). Accordingly, in order
to avoid setting treatment standards
that require excessive treatment prior to
land disposal, EPA in some cases will
employ the screening levels thresholds
to "cap" the reductions in toxicity and/
or mobility that otherwise would result
from the application of BDAT treatment,
even though the efficiencies of available
technologies may be capable of
achieving more stringent levels (i.e., the
levels will provide an upper limit on the
stringency of the treatment standard). In
the situation described above, the
screening level would become the
regulatory treatment standard since
there would be no need, from
environmental or human health
perspectives, to set a more stringent
standard.
Second, in some cases, while the
application of BDAT will result in •
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1612
51. No. 9 / Tuesday.,
substantial reductions in toxicity. and
mobility, avairable technologies-may hot
be able to achieve concentration-levels
that provide full protection of human
health (i.e.. the screening levels).
Although the statute specifies that
compliance with technology-based
standards is legally sufficient in such a '
situation, the Agency believes that the
screening levels should function as a
goal for future changes to the treatment
standards as new and more efficient
treatment technologies become
available. In this second situation, the
screening levels identify constituent
concentrations that are desird in land
disposal in-the long term, but which are
not actually required in the short, term
due to limitations in technological
capacities.
Finally, in certain circumstances, EPA
may conclude that no candidate
treatment technologies provide the
"substantial" reductions in toxicity or
mobility required under section 3004(m);
or. that all candidate treatment
technologies pose greater total risks
than land disposal. Accordingly, the
Agency would determine that there are
no treatment technologies "available"
upon which to base the treatment
standard, because even the best
demonstrated treatment technologies do
not provide sufficient safeguards against
the threats posed by land disposal or
because application of treatment
technologies would increase overall
risks to human health and the
environment. In such cases, the
screening level will become the
treatment standard, providing at least
for land disposal of wastes containing
constituents at concentrations
determined to be protective of human
health and the environment.
The development and use of these
screening levels is not required
explicitly under any of the amendments
to section 3004 enacted through the
HSWAs. EPA believes, however, that
the development and application of such
standards is reasonable and desirable
from both environmental and economic
perspectives. Economically, inclusion of
these protective caps ensures that
limited resources (natural resources as
well as financial resources) are not
expended needlessly in meeting
treatment standards in excess of what is
required to protect human health and.
the environment in the land disposal of
hazardous wastes. In addition, since the
screening level standard functions
effectively as an alternative to the
petition process (i.e., constituents that
meet the screening levels naturally are "
exempted from treatment without going
through the petition process) the Agency
expects to realize internal savings-by . -
minimizing the costly ahd
administratively burdensome petition
review process. From an environmental
perspective, EPA's efforts in developing
the screening levels will identify those
situations where even BOAT treatment
cannot achieve protection of human
health and the environment, and will
provide goals in such cases for future
technology development. Finally, EPA
believes it is desirable to employ the
screening levels as the treatment
standards in cases where no treatment
standard would otherwise be
established (e.g., in cases where all
treatment technologies are riskier than.
land disposal or when even the best
demonstrated treatment technology .
does not provide substantial reductions
in toxicity or mobility). If no treatment
standard is promulgated for a waste, the
waste and all residuals from treatment
of the waste are completely prohibited
from land disposal (unless, of course,
EPA approves petitions for continued
land disposal or applications for
effective date extensions). By employing
the levels as treatment standards in
such cases. EPA avoids forcing all those
seeking continued land disposal to
submit petitions. Instead, those forms of
waste (e.g., contaminated soils resulting
from spills or cleanup actions under
CERCLA; waste waters containing small
concentrations of hazardous
constituents; etc.) that meet the
screening level constituent
concentration levels may continue to be
disposed of in or on the land because
such disposal will not harm human
health or the environment.
The relationship of the technology-
based standards and the screening
levels can be summarized briefly as
follows. If application pf BOAT
treatment results in concentration levels
equal to or more stringent than the
screening levels, then the Agency will
issue the screening level as the
treatment standard, capping off required
BDAT treatment at these protection
levels. If application of BDAT treatment
results in levels that are less stringent
than the screening level, but BDAT does
realize substantial reductions in toxicity,
or mobility and does not pose greater
risks than land disposal, then the
technology-based Fevel becomes the
treatment standard and the screening
level remains as a goal that may be
reached as new technologies emerge. If
no technologies exist that result in
substantial reductions in toxicity or
mobility or if all treatment technologies
pose greater risks than land disposal,
then EPA will not be able to specify a
technology-based level and the '
- screening leveH>ecomes the treatment.
standard, ,,, . .
It is important to note that any waste
naturally meeting the treatment levels-
(i.e., without actually undergoing
treatment) would be, under the proposed
approach, exempted from the ban. There
would appear to be little rationale for
allowing a waste treated to those levels
to be exempted from the ban, while not
exempting a waste that naturally
contains acceptable levels so that
treatment is not required to comply with
the standard: Moreover, the language of
section 3004(m) appears to support this
conclusion. Section 3004(m) directs EPA
to specify "those levels or methods of
treatment, if any," required to
substantially diminish toxicity or reduce
mobility; The "if any" clause indicates
that EPA may identify cases where no
treatment'is required to meet the
standard; i.e., cases in which the
standard can be met without application
of technology. Accordingly, EPA is
proposing to exempt from the land
disposal prohibitions any waste treated
to meet the applicable section 3004(m)
•standard, or meeting such standard
without treatment.
In summary, in setting the effective
concentration limits that govern the
quality of land disposed wastes, the
Agency will consider a set of relevant
factors. The screening level is based on
individual risk—the first factor. The
strength of evidence for carcinogenicity
is part of the individual risk assessment
(see Unit ID. A. l.e). The performance of
treatment technologies, alone and in
relation to the screening levels has
major influence on the chosen effective
concentration limits. For example, when
a treatment substantially reduces the
concentration of a constituent in a
waste, but does not attain the screening
level the treatment performance will
become the effective control level.
Population risk will be added as a factor
if the Agency can develop a method of
using available population data. A
possible approach is described in unit
IILA.U.
The Agency believes that the
development of nationally applicable
screening levels best implements its
stated objectives of capping off
necessary treatment, providing a goal
for the development of emerging
technologies and future treatment
standards, and providing a
concentration-based standard under
section 3Q04(m) incases where a
technology-based treatment level is not
developed. In general, however, the
same objectives could be realized in the
absence of national screening levels.
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Federal Register / Vol. 51, No. 9--/ Tuesday, January 14, 1986 / Prawosed Rates
162'9
Accordingly, EPA may consider two ' '
alternative approaches.
The first alternative does not provide
for the development of screening levels
but instead relies entirely on
technology-based treatment section
standards and the petition process.
Under a regulatory framework that
provided only for the development of
technology-based (BOAT) treatment
standards (as opposed to screening
levels and technology-based standards),
the petition process could serve to "cap
off the required level of treatment so as
to avoid treatment for treatment's sake.
Under this approach, if a prescribed
level or method of treatment under
section 3004(m) resulted in
concentration levels that an owner/
operator believed to be overly
protective, the owner/operator could
petition the Agency to allow the use of
an alternative treatment level or method
or no treatment at all by demonstrating
that less treatment would still meet the
petition standard of protecting human
health and the environment.
A second major function of the
national screening level is to provide a
section 3004{m) standard in cases where
EPA is unable to develop a technology-
based standard because BOAT has not
been identified. As noted earlier, the
benefit of this approach is that instead
of banning a waste outright because
there is no technology available to treat
to acceptable levels, a waste may still
be land disposed if it can meet the
protective screening level naturally.
However, this same function could be
fulfilled by the petition process. Under
the above scenario, if EPA fails to issue
a treatment standard under section •
3004(m), an owner/operator could still
petition the Agency under § 268.5 to
allow continued land disposal of the
waste upon a demonstration that land
disposal of the waste would not result in
harm to human health and the
environment.
There is no need to develop regulatory
screening levels to meet the last major
function of such nationally applicable
levels i.e., the development of hazardous
constituent concentration goals towards
which emerging technologies can strive.
This goal could be met by the
development of screening levels in a
non-regulatory context.
The major drawback of this first
atlernative however, is that it would
increase the number of petitions
received by the Agency. Pending
determinations on individual petitions,
wastes will be restricted from land
disposal.
The Agency is also considering a
second alternative to the approach
outlined today: As noted in earlier
discussions, EPA believes that it has
authority under section 3004(m) to give
screening.levels regulatory effect in two
situatfd'ris: First, in cases'where
technology is capable of meeting or
exceeding the screening level this
protective concentration level becomes
the regulatory standard under section
3004{m), effectively "capping off the
application of technology to avoid
treatment in excess of that needed to
protect human health and the
environment. Second, the screening
level also will have regulatory effect in
cases where all candidate technologies
are riskier than land disposal or where
EPA is unable to identify a technology
that substantially reduces the toxicity
and diminishes the mobility of a
constituent. In such cases, the screening
level essentially becomes the section
3004(m) standard by default, i.e.,
because no acceptable technology has
been identified upon which to base a
treatment standard. .
This second alternative approach
would base the treatment standards
established under section 3004(m) only
on levels capable of being achieved by
the application of BOAT technology.
Under such an approach EPA would
continue to use screening levels to cap
off the use of technology, but would not
establish the screening level as the
treatment standard when no acceptable
technology has been identified. If EPA
were unable to identify a technology
that substantially reduces the toxicity
and mobility of hazardous constituents
or if ail technologies are riskier than
land disposal then the Agency would
not set a section 3004(m) standard. In
such a case, a waste banned from land
disposal could be disposed of in land
only if it is the subject of a successful
petition demonstration under section
3004(d), (e), or (g).
The petition demonstration requires a
showing that the hazardous constituents
in a waste will not migrate to a point of
potential human or environmental
exposure in concentrations that will
harm human health or the environment
(see Unit III.G). As discussed in Unit
III.A. the screening model will identify a
maximum protective concentration level
for each hazardous constituent.
Accordingly, under this approach if a
petitioner could show that all of the
hazardous constituents in his waste are
at concentrations equal to or less than
the concentration established.by the
screening model, EPA may determine
that land disposal of such a waste is
protective. With this approach, the
Agency could develop a simplified
petition process to address such cases. .
The simplified petition would consist of
a petitioner's certification, with
supporting analytical data, that all
hazardous constituents jri the waste.
meet applicable screening levels.
EPA solicits public comment on its- •
approach to developing treatment
standards. The Agency is particularly
interested in the public's views on the
desirability of developing screening
levels in addition to technology-based
standards. In addition, EPA would
welcome information indicating which
wastes (and what physical states and
what quantities) could be expected to
meet the screening levels proposed
today without treatment. To what extent
does the regulated community believe
that it will rely on compliance with
screening levels to exclude waste from
the restrictions in lieu of petitioning for
an exclusion? (screening levels for
certain solvents are identified in unit V.)
The screening levels ensure protection
of human health and the environment
considering all significant routes of
exposure. How will the establishment of
these safe levels for all hazardous
constituents affect other programs
administered by EPA or other agencies?
Under certain circumstances,
anticipated by EPA to occur extremely
infrequently or not at all, the Agency
may decide not to establish any
treatment standard under section
3004(m). This situation would arise in
cases where EPA has determined that
all applicable treatment standard for a
hazardous waste (either due to their
failure to achieve "substantial"
reductions in the waste's toxicity or
mobility, or due to EPA's determination
that they pose greater risks than those
posed by land disposal) and where the
Agency is unable to develop screening
levels. Since the screening levels
identify levels at which land disposal
may be determined to be protective of
human health and the environment, the
Agency would not be able to establish
them if, for example, critical data
elements upon which calculation of
these levels depends are absent or are
of insufficient quality. In such a case,
EPA will promulgate regulations that
certify the statutory prohibition.
Generators or facility owners or
operators desiring to continue managing
the waste in land disposal units will be
required, in such cases, to submit
petitions to EPA demonstrating such
management to be "protective" of
human health and the environment at
specific facilities, as discussed in greater
detail in subsequent units of this
preamble.
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Vrf. 51. No, & / Tuesday, January
. Regulatory atid Decision-Making
Framework
The regulatory and deetaron-makins
framework that EPA is proposing to
employ in establishing the section
3004(m) treatment standards and their
associated effective dates is presented
in schematic form in the following
Diagram 1:
BILUMQ CODE eseo-so-M
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DIAGRAM 1 \
SCHEMATIC DIAGRAM OF EPA's PROPOSED FRAMEWORK FOR THE RCRA LAND DISPOSAL RESTRICTIONS PROGRAM
O
0
0 O
Develop
Screening
Level Using
Back Calculation
Procedure
(^
X
r
Identify On-line
(Or Potential)
Technologies
Applicable To
Waste
ra
Case -By-
Case
Extensions
Or Petitions
*'
Treatment
Standard
Takes Effect
tmmodlateiv
0
Case -By
Case
Extensions
Or Petitions
Treatment
Standard
Takes Ellect
Alter
Nationwide
variance Of
Up To I*o
Years •
Treatment
Standard
Set At
Screening
Level
Case- By -
Casa
Or Petitions
Case- By -
Case
Extensions
Or Petitions
Treatment
Standard
Takes Effect
Alter
Nationwide
Variance Ol
Up To Two
Vears '
Treatment
Standard
Set At
Screening
Level
Case- By
Case '
Extensions
Or Petitions
1
m
-3
§,
a
1
1 Nationwide Variance granted only If alternative recovery and dfeposat capacity also inadequate
* Alternative treatment Technology must be l««t rHVy than land disposal and must either achieve health based threshold or- 'substantially* reduce toxtelty and dkrtnlsned Kethood ot rrMqratlon
BILLING CODE 8580-50-C
1
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1616
Feden*
/ Vol. Si, Mo. g- / Tueaday. January 14, W8ff / ftopwed Roles
By each" statutory deadline, the
Agency will employ the proposed
framework in promulgating treatment
standards under § Part 268 Subpart D
applicable to each hazardous waste.
Once such standards are effective,
hazardous wastes that comply with
these treatment standards are exempted
from the statutory prohibitions, and may
be managed in land disposal units
regulated under Subtitle C of RCRA.
Wastes that do not comply with
applicable treatment standards will be
prohibited from continued placement in
land disposal units as of the applicable
effective date, unless the generator or
owner or operator of a treatment,
storage, and.disposal facility does either
of the following:
1. Under § 268.4 submits a successful
application to EPA for an extension of
time in which to comply with the
treatment standard by demonstrating
lhat he has binding contractual
commitments to construct or otherwise
obtain alternative treatment, recovery.
or disposal capacity that is protective of
human health and the environment, and
that such capacity is not available by
the date the treatment standard takes
effect due to circumstances beyond his
control (see Unit III.F).
2. Under § 268.5, submits a petition to
EPA successfully demonstrating to a
reasonable degree of certainty that
continued management of specific
hazardous wastes in land disposal units.
including treatment and storage in
surface impoundments and waste piles.
is protective of human health and the
environment for as long as the wastes
remain hazardous (see Unit III.G).
The decision-making framework is
preceded by two sets of Agency
activities that occur simultaneously but
are entirely independent of each other,
indicated as Elements 1 and 2 at the top
center of Diagram 1. Element 1 involves
the development of the screening levels,
or caps, for individual hazardous
constituents contained in hazardous
wastes. These screening levels"identify
the concentration levels of such
constituents in hazardous wastes or
waste extracts (e.g., leachates,
emissions, etc.) at or below which
continued land disposal is determined to
be protective of human health and the
environment. Element 2 incorporates the
Agency's efforts to identify and evaluate
the effectiveness of treatment
technologies applicable to Specific types
of hazardous constituents, individual
hazardous wastes, or groups of
hazardous wastes exhibiting similar
chemical and physical properties
affecting their "treatability" (i.e.,
treatability subgroup). As noted in the
previous unit, "effectiveness," for
purposes of section 3004{m) treatment
standards, refers to the technology's
ability to diminish the toxicity of a
hazardous waste or reduce the likeihood
of migration of hazardous constituents
from the waste to air, ground water, or
surface waters.
In order to develop the screening
levels, which identify levels in land
disposal that can be deemed protective
of human health, the term "protective"
requires specific definition. Congress
provided an explicit definition of
"protective" for purposes of the land
disposal restrictions program in
specifying the standard for the petition
process established in section 3004 (d),
(e), and (g): "a method of land disposal
may not be determined to be protective
of human health and the environment
for a hazardous waste unless, upon
application by an interested person, it
has been demonstrated to the
Administrator, to a reasonable degree of
certainty, that there will be no migration
of hazardous constituents from the
disposal unit or injection zone for as
long as the wastes remain hazardous."
EPA is using this statutory definition of
"protective" for purposes of developing
the screening levels. The Agency
considered adopting a separate
definition of the term "protective" for
purposes of developing the thresholds,
but concluded that standards less
stringent than the petition standard
could not be defended as "protective."
given the clear statutory language.
EPA is not reading the statutory "
definition of "protective" as an absolute
no migration itandard. (See discussion
of petition process in Unit III.G.) The
Agency finds significance in Congress'
inclusion of the clause "for as long as
the wastes remain hazardous" as a
modifier to what otherwise would have
been a strict no migration standard, i.e.,
"no migration of hazardous constituents
from the disposal unit." The Agency is
today proposing under § 268.5 to
interpret inclusion of this modifying
clause as implying that the statutory
standard allows for some migration of
hazardous constituents beyond the
immediate confines of the disposal unit.
as long as such migration does not
present any threat to human health and
the environment Support for this
interpretation is provided in the
legislative history, where Congress
noted: "[t]he Administrator is required
to find that the nature of the facility and
the waste will assure that migration of
the wastes will not occur while the
wastes still retain their hazardous
characteristics in such a way that would
present any threat to human health and
the environment" (S. Rep. No. 98-284,
98th Conf., 1st Sess. 15 (1983)).
Accordingly, EPA is proposing to
develop the screening levels, identifying
"protective" levels in land disposal
using a conceptual system that allows
migration of hazardous constituent*
beyond disposal units but ensures that
such migration occurs at concentrations
that do not pose threats to human health
and the environment.
Screening levels are calculated for
individual hazardous constituents based
upon toxicological effects levels for
these constituents and their behavior
(fate and transport) in each of three
environmental media: Air, ground water,
and surface water. The levels are
expressed as maximum concentration
levels in extracts from hazardous
wastes that may be released from land
dispotal units. The screening levels and
their derivation are discussed in detail
in Unit III of this preamble.
The quantitative procedures
developed by EPA to calculate these
levels involve the use of constituent fate
and transport models (separate model's
are employed for transport through air.
ground water, and surface water). The
models are designed to assess the
attenuative processes (e.g., advection.
diffusion, dilution, and dispersion,
chemical transformation or degradation)
that occur during transport (migration)
of contaminants from the point of their
release from a land disposal unit (in
subsurface leachates, surface run offs,
or air emissions) to points of potential
human exposure at a specified distance
downwind, downgradient, or
downstream from the disposal unit. The
models are employed to back calculate
the maximum constituent concentration
that could be present in a hazardous
waste extract (e.g., leachate, surface,
runoff, or air emission) directly above.
below, or adjacent to a land disposal
unit such that its concentration (in air,
ground water, or surface water) at the
point of potential human exposure
would not be expected to exceed a
designated human health effect level for
the contaminant (health effects levels
are apportioned into each media through
which exposure may occur).
The following Figure 2 illustrates the
conceptual system that underlies EPA's
proposed approach to back calculating
the screening levels, using the ground
water component as an example:
-------
Fodeal Raster / VoL 5X Net ff / Taeaday, January 14. 1988 / Proposed Jfefes
LANDFILL
RECHARGE
SATURATED
ZONE
CROSS SECTION
Figure 2: Cross Section of Conceptual System for Developing
Screening. Level s
The conceptual systems for air and
surface water calculations are similar,
though tailored to the specific
characteristics of these other media and
are presented in Unit in of this
preamble. The ground water back
calculation procedure commences from
a point of potential human exposure at a
specified distance directly downgradient
from the unit, and specifies that the
concentration of a contaminant hi the
ground water, at this point cannot
exceed the apportioned health effect
leveL Defining the "point of potential
human exposure" and selecting a
corresponding distance from the -
disposal unit to thi& point are tied to the
statutory definition of "protective," and
are discussed in Unit EL
The procedure then uses fate and
transport models to determine {by back
calculation) the concentration of the
chemical constituent that may be
present in a leachate emanating directly
below the disposal unit without
exceeding its apportioned health effect
level at the point of potential exposure.
Simultaneously with establishing
screening levels, the Agency will
identify and evaluate treatment
technologies that are applicable to the
hazardous wastes included under each
deadline (Element 2 in the flow
diagram). Technologies to be identified
and evaluated include those at
commercial facilities or on-site facilities
that have been "demonstrated^ to treat
these hazardous wastes and are deemed
to be "available." 7 The process
encompassed by Element 2 also includes
the assessment of emerging treatment
technologies that are expected to be on-
line by the date the treatment standards
take effect.
The purpose of the technology
evaluations is to identify demonstrated.
available treatment technologies for .
each hazardous constituent waste, or
groups of hazardous waste* with similar
treatability characteristics. Key aspects
of these evaluations, discussed in
greater detail hi Unit EU. are:
a. Evaluations of the applicability of
treatment technologies to specific
hazardous constituents, waste streams,
or groups of wastes. "
b. Evaluations of the extent to which
each technology is actually being used
in the treatment of hazardous wastes.
1 The terms "demenstrated" and "available" are
defined in Unit 1I1.B. As used here, the term
"available" means non-proprietory. The assessment
of ^availability" in terms of comparative risk takes
pface in Element 3. The assessment of "availability"
in terms of meeting the substantial reduction test
takes place in F'pment 12.
both at off-site commercial facilities and
at oMiie facilities.
c. Evaluations of the effectiveness of
each technology in redlining the toxicity
and mobility of hazardous constituents
in wastes or groups of wastes included
under each statutory deadline.
It is important to note that cost is not
one of the factors that EPA will use
explicitly in evaluating treatment
technologies as a basis for setting the
treatment standards. Cost is, however,
implicitly accounted for in setting BDAT
standards, since technologies that are
not economically feasible are not likely
to be found "on-line" at commercial or
on-site facilities.
The proposed regulatory and decision-
making framework is composed of four
major decision-making sequences. Each
decision-making sequence leads to
establishment of a treatment standard
(and an associated nationwide effective
date) applicable to a hazardous waste,
groups of hazardous wastes exhibiting
similar treatability characteristics, or
hazardous constituents contained in
hazardous wastes.
For each waste, that is, a specific
waste stream, hazardous constituent or
waste subgroup, the first step in EPA's
proposed decision-making framework is
to exclude from consideration as a basis
for the treatment standard those
treatment technologies that pose greater
total risks to human health and the
environment in the management of the
waste than the risks posed by direct
land disposal (Element 3). As noted
previously, to ensure that total human
health and environmental risks are not
increased as a result of EPA's
implementation of the statutory land
disposal prohibitions, the Agency will
conduct risk assessments to compare
the risks of managing wastes in land
disposal units with the risks of
managing the wastes in alternative
treatment technologies, including
subsequent land disposal of any
treatment residuals. Treatment
technologies that are found through
these comparative risk assessments to
pose greater total risks than those posed
by direct land disposal of the untreated
waste will be classified as
"unavailable" for purposes of
establishing the treatment standard for
that waste. Thus, this sets the first
"break point" in the decision process.
The four decision cases, in the order of
their discussion, are cases in which the
demonstrated treatmen: technology
poses one of the following:
i. Equal or less risk than land disposal
and meets the screening level.
ii. Equal or less risk than land
disposal and does not meet the
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1618
Federal Register /..VoL 51; Mae 9 /^Tueaday, January 14> 1986 / Proposed Rules
screening level, but does substantially
reduce the waste's toxicity or mobility.
iii. Equal or less risk than land
disposal, does not meet the screening
level, and does not substantially reduce
the wastes toxicity or mobility.
o o
iv. Greater risk than land disposal.
Decision Case I—Alternative
technology poses equal or less risk than
land disposal and can meet the
screening levels.
Caw 8v-
Cate
E»t«owon»
Or Pennon*
+-
Treatment
Standard
Takes Effect
ImmeiJUteV
Caw Bv-
Cn«
C'tentioni
Or Petti new
Treatment
Standard
Tafcai Effect
After
NattorrwMe
Variance Of
Up To Two
Years'
Three sequences in EPA's proposed
decision-making framework commence
with an affirmative response in the first
critical decision component where, upon
completion of the comparative risk
assessments, treatment technologies or
treatment trains are identified that pose
risks less than or equal to those posed in
direct land disposal of the waste. These
sequences advance to the second
critical decision component in the
proposed decision-making framework,
where-the next question is posed
(Element 4): are any of these treatment
technologies or treatment trains capable
of achieving the "screening" levels for
all of the constituents known to be
contained in the waste? For those waste
streams where the answer to this
question is "yes," the decision-making
sequence proceeds with EPA's
determination that treatment technology
is "available" for such wastes and the
"screening" levels are established as the
section 3004{m) treatment standards for
each hazardous constituent in each-such
waste stream (Element 5).
Once this treatment standard is
established, the next step-in this
decision-making sequence is to
determine whether the capacity of these
"available" treatment technologies,8 in
conjunction with the capacities of
alternative recovery and disposal
technologies that are protective of
human health and the environment, is
adequate to accommodate the quantities
of each waste subject to these threshold
standards (Element 6). Capacity will be
determined on a national, as opposed to
a regional or State, basis and will
consider capacities of currently
demonstrated on-line technologies as
well as capacities of technologies that
are expected to be on-line by the
statutory deadline for each waste.
For those wastes where EPA
determines that alternative capacity is
'adequate, the "screening" level
treatment standards will take effect ,
immediately upon their promulgation
(Element 7). Since, under this decision-
making sequence, the standards are
always expressed as performance
standards (as opposed to required
methods), generators and facility
owners or operators whose wastes do
not meet the standards naturally may
employ any treatment technologies in
achieving them.9 As is the case at the
end of each decision-making sequence,
wastes that comply with applicable
treatment standards may be managed
subsequently in land disposal units,
while wastes that do not comply with
the standards are prohibited from
continued land disposal upon the
statutory effective dates unless
generators of such wastes or owners or
operators of land disposal units either
submit applications for case-by-case
effective date extensions under § 268.4,
(which, if granted, will allow land
disposal to continue temporarily under
certain conditions), or submit petitions
under § 268.5 successfully
demonstrating that continued land
disposal of the wastes is protective of
human health and the environment for
as long as the wastes remain hazardous
(Element 8). Specific procedures and
criteria to be employed by EPA in
accepting and evaluating applications
for section 3004(h)(3) case-by-case
effective date extensions and petitions
submitted under sections 3004(d), (e),
and (g) are discussed in Unit III.
For those wastes where EPA
determines in Element 6 that alternative
capacity is not adequate on a
nationwide basis, the Agency may
exercise the discretion granted to it
under section 3004(h)(2) and authorize a
nationwide variance of up to 2 years
from the statutory effective date
(Element 9). The purpose of granting
national variances in Element 9 is to
provide time for development of
additional treatment, recovery, or
disposal capacity that is protective of
human health and the environment. At
the end of the national variance, the
section 3004(m] treatment standard
takes effect. Again, case-by-case
extensions and petitions are available,
9 Note that treatment processes that are not
deemed "available" for the purpose of establishing
BOAT levels because they are proprietary are
considered in determining whether there is
adequate treatment capacity.
9 As noted earlier EPA plans to impose
restrictions or prohibitions on treatment
technologies that are riskier than land disposal. See
also discussion at Unit III.C. Such restrictions or
prohibitions may preclude or limit the use of certain
technologies in meeting these standards
-------
/Vat. St. Moy. 9 / Taesday, January 14. SS88 / Proposed Rufes
subject to EPA approval, for those who •
cannot meet the standard (Element 10),
Decision Ctae fib-Alternative
ff>rfinofogy poses equal or teas risk than
land disposal: does not meet the
screening levels, bat does svbstantiaffy
reduce toxicity or diminish mobility.
Casa -By
Casa
Extensions
Or Patittont
*»
TrMtmant
Standard
Tahn Effact
Tochnotogy
'a Avarfabl*
Traatmam
Standard
Sat 8as«d on
BCA7 Method
Or Lev«t
[c«» B»
Cu>
> Petitions
©
Traaiment
Standwd
Tafcaa EMact
Afar
Up To r«a
This sequence in EPA's proposed
decision-making framework also
commences from a favorable evaluation
of the comparative risk assessments
(Element 3). However, it (and the next
sequence) subsequently proceed from a
determination that none of the treatment
technologies or treatment trains is
capable of achieving the "screening"
level for the hazardous constituent being
evaluated or. where the .evaluation
pertains to a waste stream, for all
hazardous constituents known to be
contained in the waste. The next step in
the proposed decision-making
framework is to determine which of the
treatment technologies or treatment
trains is the "best" demonstrated
treatment technology Cor the waste.
based upon a ranking of the
technologies' effectiveness in
diminishing the waste'* toxicity or in
reducing the likelihood of migration of
hazardous constituents (Element 11).
Once the "best" treatment technology
or train for the waste is identified, the
sequence advances tothe next critical
decision component in the proposed
decision-making framework, where EPA
determines whether or not this "best"
demonstrated treatment technology or
treatment train "substantially"
diminishes the waste's toxicity or
"substantially" reduces the likelihood of
migration of its hazardous constituents
(Element 12). If EPA determines that the
"best" demonstrated treatment
technology does achieve substantial
reductions, EPA concludes that
alternative treatment technology is
"available" for the waste, and
establishes a BOAT treatment standard
(Element 13).
As noted in Unit II.B. whenever the
section 3004(m) standards are based
upon the effectiveness of BDAT, they
may be expressed either as performance
standards or required methods. If, for
example, incineration is determined to
be the BDAT for the waste, the
treatment standard may simply require
that the waste be incinerated (according
* to specified design and operating
standards) prior to its placement in land
disposal units. Alternatively, in the
same example, the treatment standard
may specify maximum concentration
levels for each of the waste's
constituents in either an extract from the
waste or in the waste itself based upon
the expected efficiency of incineration.
In this latter case, generators or facility
owners or operators would have a
certain degree of flexibility hi selecting
technologies to comply with the
standard. While EPA prefers to provide
such flexibility wherever possible, the
Agency recognizes that it may not
always be possible to specify
performance standards, due to wide
variations hi waste characteristics.
Once the BDAT treatment standard is
established, the next step in this
decision-making sequence is to
determine whether the capacity of
alternative treatment, recovery, and
disposal technologies that are protective
of human health and the environment is
adequate to accommodate the quantities
of each waste subject to these standards
(Element 14). These capacity
assessments are similar to those
described in Element 6 under me earlier
decision case.
However, in the previous decision-
pathway, the BDAT technologies were
capable of meeting the screening level
and. accordingly, would be deemed
protective of human health. In contrast,
under this decision pathway, none of the
technologies is capable of achieving the"
screening levels. The statute directs EPA
to consider only those technologies that
are protective of human health and the
environment in evaluating whether
sufficient capacity exists to
accommodate banned wastes.
Accordingly, those technologies that are
not capable of achieving the screening
level would not be considered in the .
capacity assessment. If EPA finds that
no alternate treatment capacity exists
that is protective of human health and
the environment, and if it also finds that
no protective alternative disposal or
recovery capacity exists, it may, at its
discretion, extend the effective date of a
restriction for up to 2 years under
section 3004(h){2).
However, as a matter of policy, EPA
will exercise its discretionary authority
not to extend the effective date in cases
where there is a shortfall in protective
treatment, disposal, and recovery
capacity if it determines in such cases
that existing "protective" capacity.
coupled with existing capacity of
treatment technologies that meet
technology-based section 3004{m)
standards, is adequate to address the
restricted wastes.
The Agerfcy believes that this
approach is consistent with
congressional intent The section
3004(a)(2) variance is intended to
encourage the development of protective
alternative treatment, recovery and
disposal capacity. (S. Rep. No. 98-284,
98th Cong.. 1st Sess. IS (1983), HJt. Rep.
No. 98-196, 98th Cong.. 1st Sess. 37
(1983)).
However, the regulated community
will have little incentive to develop
protective alternative treatment
methods during the variance period in
light of the fact that, at the end of any
such variance, hazardous waste may be
land disposed if the wastes comply with
less protective technology-based
standards. In such a case, the effect of
the variance would simply be to delay
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1620
Federal Register / Vol. 51. No. 9 / Tuesday, January 14, 1986 / Proposed Rules
compliance with these technology-based
standards and not, as Gongress
intended, to encourage the development
of protective alternative technologies. •
The remaining stages of this decision-
making sequence are identical to those
described under the earlier sequence.' If
a %-ariance is not granted, the BOAT
standards takes effect immediately
(Element 15), and wastes that comply
with them may be managed
subsequently in land disposal units.
Wastes that do not comply with the
standards will be prohibited from
continued land disposal unless
generators or facility owners or
operators have been granted case-by-
case effective date extensions or have
successfully demonstrated that
continued land disposal of the wastes is
protective of human health and the
environment through the petition
process (Element 16). The Agency may
also exercise its discretion under section
3004{h)(2) to grant a nationwide
variance of up to 2 years from the
statutory effective date if capacity is not
adequate (Element 17). At the end of the
national variance, the treatment
standard takes effect, with identical
regulatory outcomes to those that occur
under this sequence in the absence of a
national variance (Element 18).
Decision Case III—Alternative
technology poses equal or less risk than
land disposal, cannot meet the
screening levels, and does not
substantially reduce toxicity or
diminish mobility.
Determine Best
Demonstrated
Available Technology
(BOAT)
Does
Alternative
reatment Technology
Become Available' .
urmg Period ol
Variance?
Treatment
Standard Set
Based On Best
Demonstrated
Available
Technology
BOAT)
lelhod
Or Level
The third case in EPA's proposed
decision-making framework follows a
negative response in the third critical
decision component (Element 12), where
after identification of the "best"
demonstrated treatment technology
(El.ement 11), it is determined that
technology does not "substantially"
diminish the waste's toxicity or
"substantially" reduce the Jikelihood of
migration of its hazardous constituents.
A trc:i!rr,ont technology that does not
meet this statutory standard is
"unavailable" for purposes of
establishing section 3004 (m) treatment
standards (Element 19). If protective
disposal or recovery capacity is also
unavailable. EPA may grant a
nationwide variance for up to 2 years
under section 3004 (h) (2) (Element 20) to
allow for the development of new or
improved treatment technologies or
treatment trains that meet the minimum
requirements of section 3004 (m) for
achieving "substantial" reductions in
the waste's toxicity or mobility.
If new or improved treatment
technologies or treatment trains that
meet the minimum requirements of
section 3004 (m) are developed by the
end of the national variance (Element
21), EPA may utilize them as the basis
for promulgating a BDAT treatment
standard (Element 22), expressed either
as a performance standard or as a
required treatment method. Wastes that
comply with such standards may be
managed subsequently in land disposal
units. Wastes that do not comply with
the standards will be prohibited from
continued land disposal unless a case-
by-case effective date extension is
granted under § 268.4 or a petitioner has
successfully demonstrated that '
continued land disposal of the wastes at
a specific site is protective of human
health and the environment under
§ 268.5 (Element 23).
If new or improved treatment
technologies or treatment trains
applicable to wastes affected by this
decision-making sequence do not
develop during the period of the national
variance, EPA will establish the
screening level as the treatment
standard (Element 24). For most
generators of wastes affected by this
decision-making sequence, the
regulatory outcome resulting from this
action is not anticipated'to be
significantly different from the
regulatory outcome resulting from direct
implementation of the statutory
prohibitions. Even though a treatment
standard will have been established for
the waste, EPA will have determined
that there are no technologies that are
less risky than land land disposal that
are available to treat the waste. Except
for wastes that.naturally meet the
screening level, all hazardous wastes
affected by this decision-making •
sequence will be prohibited from
continued land disposal. Generators and
facility owner/operators must then do
one of the following:
i. Submit applications for case-by-
case effective date extensions.
ii. Submit petitions successfully
demonstrating that management of thp
-------
Federal Register / Vol. 51. Jslo. -9T / Tuesday; January m M86 /Proposed
wastes in land disposal units at specific
sites is protective of human health and
the environment
iii. Manage, the wastes by means of
alternative recovery or disposal
technologies (to the extent allowed by
law or regulation).
iv. Cease generating the waste by
means of process change or materials
substitution.
While these options also are available
under the first two decision sequences,
what distinguishes this sequence (as
well as the next sequence from the
previous sequences) is that most
generators and facility owners or
operators are not expected to be able to
comply with the treatment standard,
since no technologies are available that
are capable of achieving it.
Decision-Case IV—Alternative
technology is more risky than land
disposal.
Treatment
Standard
S«t M
ScrMnmg
l»v*l
Gas* -By-
C««
Extensions
Or P*wton*
The previous cases all stemmed from
a favorable evaluation of comparative
risk—that is, at least one alternative
technology was of equal of less risk than
land disposal (Element 3). This final
case commences with an evaluation that
all alternatives are more risky than land
disposal, resulting in EPA's
determination that treatment technology
is not available (Element 26).
Under this discision-making sequence,
EPA's first regulatory action may be to
exercise its authorities under section
3004(h}(2) to grant a nationwide
variance from the statutory effective
date for tiie.prohibition on placement of
such wastes in land disposal units
(Element 27). In this particular sequence.
alternative treatment capacity is clearly
not adequate, since the Agency will
have concluded, based upon its
comparative risk assessments, that no
treatment technology is protective of
human health and fte evironment. If
EPA finds that capacities of ."protective"
recovery and disposal technologies also
are inadequate, the Agency may grant a
variance for up to 2 years.
The purpose behind granting the
nationwide variance under this final
decision-making sequence is to provide
affected generators and facility owners
and operators an opportunity to develop,
new technologies or improve existing
technologies such that the minimum
requirements of section 3004(m) are
achieved and .the risks of managing
wastes through diese technologies are
not greater than the risks associated
with land disposal of the wastes
(Element 28).
By the end of the nationwide variance
(which may not exceed 2 years), EPA
may promulgate a section 3004(m)
treatment standard if, during the period
of the nationwide variance, new or
improved treatment technologies are
developed that meet the minimum
requirement of section 3004(m) and do
not pose greater risks than those posed
by land disposal (Element 29). The
BOAT standard would take effect
immediately at the end of the
nationwide variance.
As indicated earlier, once die Section
3004(m) treatment standards take effect.
wastes that comply with them may
continue to be managed in land disposal
units. Wastes that do not comply will be
prohibited from continued placement in
land disposal units after die effective
date unless generators or facility owners
or operators have been granted case-by-
case extensions of the effective date or
have submitted petitions successfully
demonstrating that continued land
disposal of die wastes is protective of
human health and the environment
(Element 30).
Under this decision-making sequence, •
however, if new or improved treatment
technologies or treatment trains
applicable to waste affected by this'
decision-making sequence do not
develop during the period of die
nationwide variance, EPA will continue
to determine that treatment technology
is not "available" for these wastes and
will establish the screening levels as the
treatment standards (Element 31).
Options available to the generators and
owners or operators are the same as
those described in Decision III, when n.o
treatment technology is-"available"
/{Element 32).
This completes the description of
EPA's proposed decision-making
framework for exercising its
responsibilities in implementing the
statutory prohibitions on land disposal .
enacted in section 3004 (d), (e), and (g).
including establishing section 3004{m)
treatment standards and their .
associated effective dates. EPA has
applied this framework in today's
proposal to two classes of hazardous
wastes—certain dioxin-containing
wastes and certain solvent wastes. EPA
requests comment on all aspects of
these four decision pathways.
C. Treatment Standards andEffective
Dates for Solvents
Pursuant to section 3004(e), EPA has
applied die proposed decision-making
framework in developing section
3004(m) treatment standards (40 CFR
Part 268, Subpart D) for solvent wastes
(EPA Wasts Cddes F001 through F005,
P002. U031, U002. U037, U052, U057.
U070. U080. U112, U117. U140. U154.
U159. U161. U169, U196. U210, U211.
U220. U226. U228, U121. and U239).
I.' Screening Levels/Liner Protection
Threshold
Screening levels were back calculated
for all applicable solvent constituents
contained in these wastes, based upon
their chemical, physical, and
lexicological properties. However, in
addition to toxicological threats, solvent
wastes may also adversely affect liners
and may mobilize other hazardous
constitutents contained in land disposal
units. Accordingly, EPA is proposing
today to establish a liner protection
threshold concentration level of 2 ppm
to guard against these additional threats
posed in the land disposal of solvent
wastes, based upon the lowest
concentration know to adversely affect
synthetic liners in short term tests and a
hundredfold safety factor. Wherever the
lexicologically derived screening levels •
are greater than 2 ppm or where ever the
levels are not developed due to the
absence of toxicological data (e.g., for
ignitable solvents), this concentration
level will be used as an override,
replacing the screening level for the
constituent.
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Federal Register / Vol. SI, No.-9 / Tuesday. January 14. 1986 /. Propoaed Rules
2. Best Demonstrated Achievable
Technologies
EPA has-determined that a number of
technologies are applicable to the
treatment/recovery of solvent wastes,
including biological degradation, steam
stripping, carbon absorption, distillation,
incineration, and fuel substitution. The
Agency is proposing to identify "best
demonstrated achievable technologies
for each solvent waste based upon the
waste's physical form, the specific
solvent constituents it contains, and the
concentrations at which such
constituents are present. For all solvent
wastes subject to today's proposed
rulemaking, best demonstrated
.treatment technologies are identified"
that are capable of achieving the
screening levels for the applicable
solvent constituents contained in these
wastes. Furthermore, although final
evaluations have not yet been
completed, preliminary results indicate
that these best demonstrated treatment
technologies do not pose total risks to
human health and the environment
greater than those posed in the direct
land disposal of most categories of the
solvent wastes subject to today's
proposed rulemaking. Detailed analysee
are underway, however, to evaluate
risks posed by the treatment of certain
categories of solvent waste streams in
steam strippers and incinerators. Since
greater risks may be posed by these
technologies only for a small subset of
the solvent wastes subject to today's
proposed rulemaking. EPA is continuing
to classify both of these technologies as
available treatment technologies for
purposes of establishing the section
3004(m) treatment standards until the
results of the detailed analyses are
available.
3. Proposed Section 3004(m) Treatment
Standards
EPA is proposing section 3004(m)
treatment standards (40 CFR Part 268,
Subpart D) for each of the-subject
solvent waste streams under Decision
Sequence 1 of the proposed land
disposal restrictions decision-making
framework. The Agency has determined
that the screening levels for each
Appendix VII solvent constituent
(including all situations in which EPA is
proposing to override the lexicologically
derived thresholds with the 2 ppm liner
protection threshold) can be achieved
by the best demonstrated achievable
treatment technologies identified for the
various categories of solvent waste
streams. Accordingly, EPA is proposing
the screening level or liner protection
threshold as the section 3004 (m)
treatment standards for each Appendix
VII constituent contained in the solvent
wastes subject to today's proposed "
rulemaking, capping off the required
technology performance levels at these
protective levels.
4. Effective Dates
EPA is proposing to establish
immediate effective dates (i.e.,
November 8,1986) pursuant to section
3004(e) for all but three of the categories
of solvent wastes subject to today's
proposed rulemaking. The Agency bases
its proposed decision not to grant
national variances under section 3004
(h)(2) for these solvent wastes upon
determinations that available capacities
of treatment technologies capable of
achieving the proposed treatment
standards for these wastes, in
conjunction with the capacities of
alternative recovery and disposal
technologies, are sufficient to
accommodate all of the quantities of
these solvent wastes that are currently
land disposed. Accordingly, solvent
wastes subject to today's proposed
rulemaking that do not comply with
applicable section 3004(m) treatment
standards will be prohibited from
continued land disposal commencing*
November 8,1986, unless case-by-case
effective date extensions are granted
under section 3004 (h) (3) or unless
petitions for continued land disposal are
approved under section 3004(e). '
EPA is, however, proposing to grant a
2-year national variance, the longest
effective date variance authorized under
section 3004 (h)(2), for these categories
of solvent wastes subject to today's
proposed rulemaking: Solvent-water
mixtures (wastewaters) containing less
than 1 percent (10,000 ppm) of total
organic constituents and less than 1
percent (10,000 ppm) of total solids;
inorganic sludges and solids containing
less than 1 percent (10,000 ppm) total
organic constituents; solvent-
contaminated soils. The Agency bases
the proposed national variances for
these solvent wastes upon a
determination that the capacities of
alternative treatment technologies
capable of achieving the treatment
standards for these wastes (wastewater
treatment units and incinerators), in
conjunction with the capacities of
alternative recovery and disposal
technologies, are insufficient to
accommodate the quantites of these
solvent wastes currently managed in
land disposal units. Accordingly, the
section 3004(m) treatment standards
proposed for these two categories of
solvent wastes will not take effect until
November 8,1988.
D. Treatment Standards and Effective -
Dates for Dioxins
Pursuant to section 3004(e), EPA has
applied the proposed decision-making
framework in developing section
3004(m) treatment standards (40 CFR
Part 268, Subpart D) for dioxin-
containing waste (EPA Waste Codes
F020, F021, F022, F023, F026, F027, and
F028, containing particular chlorinated
dioxins, -dibenzofurans, and -phenols).
1. Screening Levels
Screening levels were~back-calculated
for each Appendix VII hazardous
constituent contained in these wastes,
based upon their chemical, physical, and
lexicological properties. In many cases,
the screening levels calculated for these
constituent are below established
deteclion limils achievable using
slandard EPA analytical melhods.
2. Besl Demonslraled Achievable
Technologies
EPA has determined that the best
demonstrated technology applicable to
the treatment of dioxin-containing '
wastes is incineration at 99.9999 percent
destruction or removal efficiency (six 9s
DRE) or an equivalent thermal treatment
technology. Furthermore, the Agency
has determined that incineration to six
9s DRE does not pose total risks to
human health and the environmenl that
are greater than those posed in direct
land disposal of the dioxin-containing
wastes subject to today's proposed
rulemaking. However, the Agency
cannot state conclusively that
incineration at six 9s DRE can achieve
the screening levels for these dioxin-
containing wastes, since many of the
levels are below established deteclion
limils (due lo Ihe highly loxic nature of
the chlorinated constituents).
3. Proposed Section 3004{m) Treatment
Standards
EPA is proposing section 3004(m)
treatment standards (40 CFR Part 268,
Subpart D) for each of the subject
dioxin-containing waste streams under
Decision Sequence 2 of the proposed
land disposal restrictions decision-
making framework. The Agency has not
been able to determine thai Ihe
screening levels for each Appendix VII
constituenl can be achieved by the best
demonstrated available treatment
technology identified for these wastes.
Incineration at six 9s DRE has been
identified as the best demonstrated
available technology for these dioxin-
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Federal Register / Vol. 51,vNp, 9 / Tuesday., January 14, 1986 / .Proposed Rules.
containing wastes, and the Agency has
determined that incineration at six 9s
DRE achieves substantial reductions in
the mobility and to^fcity of these dioxin-
containing wastes arid their chlorinated
constituents. Incineration at six 9's DRE
is expected to reduce the concentration
of the dioxins of concern to levels below
established EPA detection limits
(detection limit 1 ppb). Accordingly, the
Agency is proposing to specify the
section 3004(m) treatment standard at
the detection limit (1 ppb), and to
identify the back-calculated screening
levels for these wastes as the long-term
goals toward which future treatment
standards will aim as current analytical
methods are improved or new methods
of detection are developed. Accordingly.
under EPA'-s proposed treatment
standard, all dioxin-containing wastes
will be prohibited from placement in
land disposal units unless first treated in
accordance with the treatment
requirements specified in §§ 264.343.
265.383, 265.352, if any levels of the
chlorinated dioxins, -dibenzofurans, and
-phenols are detected in extracts
(leachates) from these wastes.
Conversely, under today's proposed
treatment standard, land disposal
without prior incineration will be
permitted for all dioxin-contaminated
wastes whose chlorinated constituents
are not detected in EPA's approved
leachate test procedures.
4. Effective Dates
EPA is proposing to grant a 2-year
national variance, the longest effective
date variance authorized under section
3004(h)(2), for all dioxin-containing '
wastes subject to today's proposed
rulemaking. The Agency bases the
proposed national variance for these
dioxin-containing wastes upon a
determination that na incinerator or
thermal treatment facility has yet been
approved by EPA to treat dioxin-
containing wastes, and that no
alternative recovery or disposal
technologies have been identified that
are protective of human health and the
environment in the management of these
highly toxic wastes. Accordingly,
today's proposed section 3004(m)
treatment standard, requiring
incineration of dioxin-containing wastes
at six 9s DRE prior to placement in land
disposal units, will not take effect until
November 8,1988, The Agency will .
reconsider the length of this national
variance and may institute an earlier ..
effective date if one or more facilities
are certified to treat these dioxin-
containing wastes.'
III. Detailed Analysis of Proposed
Regulatory Framework
A. Conceptual Approach To
Establishing Screening Levels
As discussed in Unit II, EPA proposes
to develop both technology-based levels
and screening levels to establish
treatment standards. This unit discusses
the Agency's approach to establishing
screening levels. In order to identify
when land disposal of a hazardous
waste is protective of human health and
the environment for the purpose of
determining screening levels, EPA has
established a comprehensive modeling
approach which will be used to assess
potential adverse effects to human
health and the environment through
release of contaminants from land
disposal units to ground water, surface
water, and air. Today's notice specifies
screening procedures for both ground
water and surface water exposure. In
addition, EPA's general approach to the
air exposure model is described.
However, this component has been
sufficiently developed for inclusion as a
specific proposal in today's rule. EPA
anticipates issuing the specific proposal
for the air exposure evaluation
component for publication in the Federal
Register within the next 6 months.
The ground water and surface water
screening procedures use concentration-
based fate and transport models that
start from a potential point of human
exposure at a concentration deemed to
be protective of human health or the
environment and bat;k calculate the
constituent concentration in a leachate
immediately beneath or adjacent to the
land disposal unit that will ensure that
the specified protective level is not
exceeded at the point, of potential
exposure. In those cases where EPA
specifies the treatment standard as a
leach concentration, a new extraction
procedure will be used to determine if
an extract from a waste exceeds the
specified level. Use of an extraction, or
leaching procedure, provides a
mechanism for accounting for the entire
spectrum of physical forms of a waste.
Accordingly, use of the extraction
procedure allows recognition of the fact
that physical form (i.e., the waste
matrix) will influence the teachability of
constituents in the waste.
Generally, predictive modeling, such
as that being used to back calculate
acceptable constituent concentrations.
is done on a site-specific basis.
However, use.of a site-specific approach
would provide only for an evaluation of •
existing land disposal units, and would
not guarantee protection of human
health and the environment at future
disposal sites. In addition, EPA would ,
not be able, to make site-specific
evaluations of necessary treatment
levels within the timeframes for
decision-making provided by the statute.
As a result, EPA has concluded that the
most reasonable and efficient approach
to carrying out the statutory directive is
to develop a generic scenario on which
to base the levels. Because these levels
are intended to identify levels that are
protective, to the best of EPA's
knowledge, at all existing and future
land disposal sites, and thereby define
when wastes can be land disposed
without prior treatment* the assumptions
used in modeling must be conservative,
i.e., representing a reasonable worst
case.
The screening procedures are generic
in two ways. First, a universal facility
type was developed representing a
closed landfill, waste pile, or surface
impoundment. In other words, EPA is
setting a single screening level for a
constituent in a waste, regardless of
what type of disposal unit the waste will
be placed in, unless the waste will be
injected into an underground injection
well. (As explained previously, the
framework and treatment standards
being proposed today do not apply to
injected wastes.) EPA is also
considering distinguishing one other
type of disposal facility—land
treatment—in establishing treatment
standards. EPA's considerations and
plans in this area are discussed more
fully in Unit IV of this preamble.
The Agency believes that the statute
does provide the discretion to issue
treatment standards that vary based on
^the type of land disposal unit that the
'waste will be placed in. However, the
Agency further believes that the statute
does not require that such distinctions
be made in establishing treatment
standards under section 3004{m). The
Agency realizes that the generic
approach to establishing screening
levels does not take into account the
multitude of variations that exist among
different types,of land disposal units
and that some types of units may result
in a higher level of protection than the
generic unit used as the basis for
calculating screening levels. Consiatent..
with the overall philosophy of the
proposed framework, EPA believes that,-
generally, variations in facility design
and operation, can best be considered on
a site-specific basis through the petition
process.
Secondly, the screening procedures
are generic in the sense of the. •
environmental setting of the modeled
scenario. In order to address the range
of possible environmental settings (e.g..
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16a* Federal Register/Vol. jft. No, g / Tuesday. January 14,1986 / Proposed Rules
climatic condition, hydrogcology), the
Agency developed a Monte Cario
simulation method for establishing the
back-calculated health-based
thresholds. This approach
accommodates possible variations in
environmental settings, the uncertainties
in specific chemical properties, and the
range of impact of engineered system
releases from land disposal units.
Instead of specifying a single value for
each input parameter to the model,
representing a reasonable worst case,
the Monte Carlo simulation method
involves a large number of computer
runs with values for each input
parameter drawn from data sets
describing the range of possible values
for each parameter and the distribution
of values within the range. Additionally,
where parameters are correlated, and
therefore dependent, the relationships
are accounted for in the Monte Carlo
routine. The output from the Monte
Carlo routine (e.g., 1.000 runs) can then
be organized into tabulated values or
graphical presentations of cumulative
frequency distributions. In this manner
the back-calculated screening
concentration selected for any
hazardous constituent can be evaluated
for its probability of occurrence.
As a matter of policy, the Agency
proposes to select the 90 percent level of
the Monte Carlo probability distribution
as the appropriate regulatory level. In
this case, the level of treatment selected
will ensure that downgradient
concentrations will not exceed the
specified target concentration in more
than 10 percent of all possible settings
for RCRA Subtitle C iand disposal units.
The Agency believes that selection of
the 90 percent level is reasonable
because of the extreme unlikelihood that
hazardous waste land disposal facilities
would be sited in the very worst
locations. EPA believes that selection of
a level higher than 90 percent would
result in setting screening levels on
highly improbable scenarios. Analysis
based on currently available
information on existing hazardous waste
facilities indicates that the facilities
analyzed fall well below this 90 percent
level (Ref. 2). However, as farther data •
becomes available, the Agency will
continue to examine the appropriateness
of this level
The Agency is also considering an
alternative method of deriving the
effective screening levels for •
carcinogens from the distribution of
results from the back-calculation
models. Under this alternative, the
Agency would choose a cutoff percentile
such that the target protection level (e.g.
10~4) is achieved in most cases and the
risk to individuals falling beyond the
cutoff also falls in the acceptable risk
range.
• To meet these objectives, the
maximum risk posed in cases beyond
the percentile cutoff (which can be no
greater than the risk of directly ingesting
full strength leachate). is required to fall
within the Agency's acceptable risk
range of 10~* to 10-T).'Ingestion of full
strength leachate is a conservative
assumption but necessary to estimate
the potential risk in cases beyond the
cut-off point. (The actual risk in those
cases is likely to be much less.) For
example, if the 75th percentile point on
the Monte Carlo distribution is selected,
then the corresponding leachate level
(screening levels) will assure that in 75
percent of the scenarios modeled, the
chemical and physical characteristics of
the waste disposal scenario will result
in dilution of the leachate down to a 10~*
risk level (i.e., the target risk level) by
the time it migrates a distance of 500
feet downgradient. The risk to exposed
individuals in these scenarios will be
less than or equal to 10~*. In the
remaining 25 percent of scenarios the
MEI risk will be greater than 10-*, but
will never be greater than the risk posed
by drinking pure undiluted leachate.
Thus, the maximum risk can be assured
to remain within the Agency's
acceptable risk range of 10~* to 10~7 by
selecting a leachate limit (screening
level) that itself is associated with a risk
no greater than 10~4 (by comparing the
leachate limit corresponding.to each
point on the Monte Carlo distribution
with its associated risk from the
constituent's dose response curve).
, Accordingly, in selecting the
percentile cutoff for'each constituent,
one would move down the Monte Carlo
distribution to the lowest percentile
point where the associated threshold
concentration (leachate standard) still
falls within the Agency's acceptable risk
range. A more complete discription of
this alternative may be found in the
record for this rulemaking.
In developing the ground water and
surface water screening procedures, it is
necessary to specify a distance
representing a potential point of human
exposure. As discussed previously, EPA
interprets the statute to require that
there be no migration to a point of
potential exposure at a level that can
cause adverse health or environmental
effects. Because the legislation and
legislative history indicate Congress'
concern with- the long-term uncertainties
associated with land disposal, selection
of the exposure point based on the
current location of exposed individuals
is inappropriate. Rather, the exposure
point must represent a point of potential
the facility, as weQ as after the closure
and the post-closure care periods. This-
is because exposure, particularly to very
persistent and slow-moving
constituents, can occur many years after
the facility has closed.'
EPA has defined the point of potential
exposure in terms of an area of effective
control; i.e., the area over which an
owner/operator can exercise control
designed to ensure that there will be no
exposure to hazardous constituents at
concentrations that adversely effect
human health or the environment. This
approach is consistent with both the
exposure point being proposed today for
the petition process under § 268.5 as
well as the definition of potential
exposure for determining alternate
concentration limits pursuant to the Part
264 ground water protection program
(Ref. 98). Under this approach,
constituent concentrations are predicted
not. to exceed the health effect levels
beyond the area of effective control.
Thus, the approach assures protection of
resources such as ground water beyond
the exposure point regardless of
whether they are currently being used
for human consumption. Designation of
an appropriate exposure point is
discussed in more detail in Unit m.A.2,
3, and 4.
In selecting appropriate models for the
proposed screening procedure, a number
of existing models were evaluated. The
criteria for this evaluation were as
follows:
(1) The model must be suitable for a
generic application.
(2) To be suitable for use with an
extraction procedure, (i.e., to be able to
account for differences in physical form
of a waste), the models must fit into or
be easily modified for use in the back
calculation procedure and model
outputs must be expressed as a
concentration.
(3) Because of the time constraints
imposed by the legislation for refining
existing data or developing additional
data, the data requirements of the model
should not be extensive.
(4) The models should account for, to
the extent allowed by the state-of-the-
art, the major physical/chemical
processes known to affect the fate and
transport of constituents through the
environment
Based on discussions with experts in
the field, the Agency determined that
the available ground water fate and
transport models considered did not
meet all four selection criteria.
Specifically, although the analytical
models required relatively limited data
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ttaghter / VoL 81. JMofefl j Tuesday. January 14. 168g ^ Proposed Rates
inpvts. aoae satisfied all of the three
rBmannag criteria: Most were developed
for different application* and could not
be applied to tie desired generic
scenario. The numerical models
evaluated required extensive data
inputs and were more applicable to site-
specific evaluations than to the desired
generic evaluation. Additionally, the
Agency determined that none of the
analytical or numerical models could
easily be modified to meet all fow
criteria.
As a result, the Agency investigated
alternatives including the use of a one-
dimensional advective-dispersive
equation which also accounted for first-
order decay of hazardous constituents.
Because this equation failed to account
for processes known to occur in the
ground water environment the Agency
rejected Us usa With assistance from
experts in the field, the Agency selected
a two-dimeasional advective-dispersive
transport model which met all of the
evaluation criteria. This model accounts
for most of the major physical and
chemical processes known to influence
movement and transformation of
chemicals in ground water. The model
was presented to EPA's Science
Advisory Board (SAB) for review. Based
on comments received from the SAB
(available in the docket for this
rulemaking). the Agency revised the
ground water model to address the
major points of concern including the
assumption of complete mixing of
leachate over the aquifer, speciation of
metals in ground water, and the related
subjects of variabiity and the generic
nature of the screening procedure. The
model relates, through mass balance
principles, the mass flux of leachate
emanating from land disposal units to
the nature j)f the leachate (or
penetration of leachate) after it is mixed
in the aquifer. The Agency estimated
long-term flux rates, from a RCRA
Subtitle C land disposal unit asing the
Hydrologtc Evaluation of Landfill
Performance (HELPj awdeL The HELP
model was developed by EPA
specifically as a tool for estimating
water budget components of lanrifii)
rlf^gjgrni The water budget components
include runoff, evapotraaopiration.
surface drainage and leachate resulting
from infiltration. HELP uses
climatologic, soils, and design data to.
produce daily estimates of water
movement across, into, through and out
of landfills. PredpilatioQ in excess of
losses due to surface ruaoff and
evapotra&spiration will result in net
infiltration to soils. The Agency
considered net infiltration to be
comparable to. long-term chenkad Sax
from land disposal units.
Estimates of metal species
distributions in ground water wiii be
determined using the geochetntcai model
MINTEQ. MINTEQ is an equilibrium
model that uses the equilibrium constant
approach to solving the chemical'*
equilibrium problem. Because different
species of a metal cause different
biological effects, this model better
relates metals concentrations ami
ground water chemistry to observed
effects.
The proposed ground water screening
procedure accounts for most of the
major physical and chemical processes
known to influence movement of
chemical* in simple, homogeneous and
isotropic porous media under steady
flow conditions The mechanisms
considered include the process by which
solutes are transported by the bulk
motion of flowing ground water;
dispersion or spreading of contaminants
as they move with the ground water in
the longitudinal, lateral, and vertical
dimensions (x. y. z planes); sorptioa or
intereaction of dissolved contaminants
with aquifer solids encountered in the
flow path; first-order decay for organics
limited to hydrolysis; and speciation of
metals in ground water. The mode! also
incorporates several reasonable worst-
case assumptions,, such as saturated soil
conditions providing zero attenuation,
and infinite source which supplies a
continuous input to the ground water
environment, and a receptor well
directly in line with the source and
groond water flow. A more detailed
discussion of the ground water model,
including the various component models
such as HELP and MINTEQ, is
contained in Unit III.A.Z. Additional
specificdetatfe on the MINTEQ
component of the model will be
published in the proposed nttemaking
for constituents addressed by section
30M(d}, Le., the California List.
Development of the proposed surface
water screening procedure was guided
by the same requirement* as the ground
water component. The Agency
determined that none of the existing
analytical or numerical computer
models could easily be modified to meet
all toe criteria. Since numerical
solutions are more applicable to site-
specific evaluations and not the desired
generic evaluation, an analytical
solution was chosea for its
computational simplicity.
After reviewing available analytical
solutions to the major zones of interest
in the stream, the Agency selected
lateral dispersion near the area of
leachate entry into the stream and a
one-dimensional zone downstream from
the area of leachate entry where the
stream is completely mixed. Two
solutions were developed for the
governing equations. Both approaches,
based on mass balance principles but
using different boundary conditions,
produce similar results, thereby
confirming the operational model {the
computer code resulting from the
equations}.
The proposed surface water screening
procedure accounts for the major
physical and chemical processes known
to influence a stream. The important
mechanisms considered include initial
dilution; advection; dispersion in the
longitudinal and lateral dimensions;
degradation; and sorptkm. The
procedure also incorporates several
reasonable worst-case assumptions,
such as the contaminated ground water
intercepting the stream contin«ously,.the
fish residing in the most contaminated
portion of the stream, and no loss daring
overland flow (i.e., adsorption,
dispersion, and chemical
transformation). The mechanics of die
surface water model are discussed
further in Unit IBLAJ.
Through the use of conservative
modeling assumption, conservative back
calculation starting points and selection
of the 90 percent level in the Monte
Carlo probability distribution, the
Agency believes that the screening
levels represent levels that are, to the '
best of EPA's knowledge, protective at
future and existing hazardous waste
land disposal sites. Constituents at
levels below these screens are
considered not to be of regulatory
concern and thus may be land disposed
at any Subtitle C facility. It is likeiy,
however, that levels above these
thresholds may be protective at specific
sites". Under the framework established '
in today's proposed rule, site-specific
factors that could result in a
determination that higher levels are
protective can be considered through the
petition process described in Unit III. G.
A detailed description of the
determination of the appropriate starting
level for the back calculation, as well as
die screening procedures for ground
water, surface water and air exposure.
follows.
1. Back Calculation Starting Points
a. Constituents of concern. As noted
earlier, in developing screening levels
that are protective of human health and -
the environment, EPA will define
"protective" as that term is used in
section 3004 (d), (e), and (g). Specifically.
these subsections provide that EPA may
not determine that a method of land
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Federal Register / Vol. 51, Not 9 / Tuesday. January 14. 1986 / Proposed Rules
disposal is "protective" for a certain
waste unless it is demonstrated that
"there will be no migration of hazardous
constituents from the disposal unit or
injection zone for as long as the waste
remains hazardous," The term
"hazardous constituents" is used in 40
CFR 264.93 to connote constituents
listed in Appendix VIII to 40 CFR Part
261. It is presumed that Congress was
cognizant of this usage and intended the
term to have the same meaning in
section 3004 (d). (e), and (g). Indeed, in
the legislative history to new section
3004(u) of RCRA, which also uses the
term "hazardous constituent," Congress
explicitly states that "[the] term
'hazardous constituent' as used in this
provision is intended to mean those
constituents listed in Appendix VIII of
the RCRA regulations" (H.R. Rep. No.
98-198, 98th Cong., 1st Sess. 60 (1983)).
Absent an indication of contrary intent,
it is presumed that Congress intends a
term to be given consistent meaning
throughout a statute.
Thus, in requiring a showing of no
migration of "hazardous constituents"
under section 3004 (d), (e), and (g),
Congress appears to indicate that land
disposal of a particular hazardous waste
may not be found protective unless it is
demonstrated that there will be no
migration of the Appendix VIII
constituents of that waste from the
disposal unit for as long as the waste
remains hazardous. This, in turn, implies
that in order for land disposal of a waste
to be deemed "protective" by virtue of
compliance with screening standards
established under section 3004(m), it
must be demonstrated that all Appendix
VIII constituents in that waste meet
applicable threshold levels. In order to
make this determination, EPA must set
screening levels for all Appendix VIII
constituents.
The foregoing interpretation seems
consistent with congressional intent
when applied to decisions on the
"protectiveness" of a waste under
section 3004(g). It seems dear that
Congress intended EPA to consider
directly or indirectly all-Appendix Vin
constituents in making-a finding that a
waste addressed by this section is safe
for land disposal. However, EPA
believes that Congress intended a
different treatment for wastes regulated
under section 3004(d) and (e). These
subsections identify wastes that require
attention in the near term to address
specific enumerated constituents of
concern. Thus, the"wastes listed in
section 3004(e) (i.e., solvent- and dioxin-
containing wastes) are to be evaluated
for their solvent and dioxin content
within 24 months of enactment. The
wastes identified in section 3004(d) (i.e.,
wastes containing certain listed
constituents) are to be examined within
32 months to determine whether the
specified metals, corrosives, PCBs and
halogenated organics are present in
unacceptable concentrations. EPA
believes that these "fast-track"
decisions are intended to focus only on
the enumerated constituents of concern
and not upon all Appendix VIII
constituents in such wastes. Wastes
containing unacceptable concentrations
of the specified constituents will be
banned from land disposal. Wastes
containing such constituents in
acceptable levels will be further
evaluated for all other Appendix VIII
constituents when EPA addresses listed
and characteristic wastes under section
3004(g).
The Agency is now in the process of
assessing data needed to establish
health effect levels for all Appendix VIII
constituents. The development of valid
data is a time-consuming process. Little
is known about the toxic effects of many
of these constituents. Accordingly, EPA
may not be able to generate information
necessary to establish screening levels
for all Appendix VIII constituents
contained in the first group of scheduled
wastes by the statutory deadline of
August 8,1988 (i.e., 45 months from
enactment). If such an eventuality
develops, the Agency is considering
pursuing one of three alternatives to
address the statutory directive.
First, EPA may consider developing
data to support the establishment of
surrogates for certain Appendix VIII
constituents. Under this approach, EPA
would attempt to draw an analogy
between the toxic effects of a chemical
for which there are well-documented
toxicological data and the toxic effects
of one or more Appendix VIII
constituents with similar molecular
structures for which few toxicological
data are available. This process,
quantatitive structure activity
relationship (QSAR) analysis, has been
used to predict the toxicity of chemicals
to mammalian and aquatic species. The
process relies heavily on the
professional judgment of toxicologists
and chemists, and to a limited extent, on
computer modeling. Second, EPA may
consider amending the existing
regulations to delete, for purposes of the
restrictions program, consideration of
many of the exotic Appendix VIII
constituents for which toxic effects data
are not available. The constituents
considered for deletion would be those
that are expected to be present in very
few, if any; hazardous wastes.
Finally, EPA may adopt an approach
which provides that wastes containing
hazardous constituents for which health
effect levels have not been developed
will be automatically banned from land
disposal unless the waste complies with
applicable technology-based
pretreatment standards or is the subject
of a successful petition. Under this
approach, it is assumed that a successful
petition would have to demonstrate that
the constituents for which toxic effects
data are unavailable will not reach the
receptor point, or the petitioner would
have to develop sufficient data on the
toxic effects of the constituent in
question to provide EPA a basis for
determining that the constituents in
question will not migrate to the receptor
point at a level in excess of "safe"
concentrations. It is also assumed that
sufficient data will be available to
conclude that a treatment technology
that adequately addresses certain
constituents (for which sufficient
toxicological and treatability data are
available) will also adequately address
Appendix VIII constituents for which
there are insufficient toxicological data,
but which can be expected to respond to
treatment in a similar manner because
of similar molecular structure.
EPA solicits comment on these
alternative approaches to addressing
Appendix VIII constituents in the
absence of complete toxic effects data.
b. Chronic v acute effects. There are
two patterns of toxic chemical
exposure—chronic and acute—which
give rise to somewhat distinct responses
in the individual exposed and require
different strategies for control. The
kinds of events unique to land disposal
which result in chronic, recurrent
exposure are the undetected, inevitable
and widespread deterioration of
synthetic liners and the underlying
containment system. Thus, the primary
intent of the restrictions program is to
address the problems of the long-term,
unpredictable failure of land disposal •
leading to chronic exposure. The
legislative history clearly states this
intent of Congress. "The objectives of
this program are twofold ... the
second objective is to ensure that land
disposal is used only for those wastes
for which it can reasonably be
anticipated to be protective of human
health and the environment in the very
long term even if there are no treatment
alternatives." (H.R. Rep. No. 98-198,98th
Cong., 1st Sess. 30 (1983)). "The program
is based upon a finding that land
disposal in general is the least desirable
form of waste management because of
the problems associated with assuring
long-term containment of hazardous
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Federal Regbrter /Vol.SI, No. 9 / Tuesday, January-14, 1966 / Proposed Rules
1GS7
waste." (S, Rep, No. 98-284.9Wh Cong-
1st Sess. 13 (1983Q. Brants causing acute
effects are usually sodden and not-.
recurrent e;g^ fires, explosions and
spills—problems iahemU in any waste
management activity; The Agency has
already promulgated restrictions and
other regulations to address these
events, (see 40 CFR Parts 284 and 270)r
therefore, they are not the 'primary focus
of the restrictions program. Moreover,
concentration levels based on ehronk:
effects should protect against acute
harm. Tolerable levels for acute
exposure are often set higher than the
corresponding levels for chronic
recurrent exposure because in the acute
" case physiological repair may take place
before any subsequent exposure. For
example, EPA-esiabiished emergency
levels (health advisories) for brief
exposure to containments in drinking
water Hkely would be higher than the
levels set for these same contaminants
under chronic exposure.
c. Single coastitaeats v mixtures. In
establishing screening levels, individual
constituents in each waste must be
evaluated. Under the approach set forth
in this proposed role, each constituent
will be considered independently.
The assumption that each chemical
behaves independently means that no
interactive effects (e-g.. antagonism.
synergism or additive) in the
environment or upon the human system
are considered in the initial screening
levels. Interactions can be dependent on
(he nature of the chemicals, the
mechanism of lexicological effect as
well as possible species-specific
metabolism. EPA believes it does not
have adequate data to characterize
these relationships and. accordingly, is
unable to set limits based on interactive
effects. In the future it may be possible
to modify existing reference doses (L
health limits) to reflect the potential
interactions when more data are
available.
d. Noncarcinogeaic constiiueats.
Implementation of the various back.
calculation models requires the initial
input of a single heakh-based limit for
each constituent. Determination of the
appropriate health-based Emit is
dependent upon the nature of fhe toxic
effect of the constituent, specifically
whether or not the constituent is a
carcinogen.
Substances which cause-systemic
toxicity (i.e., other than cancer), appear
•to do so through mechanisms'which
exhibit physiological thresholds. Thus, a
reserve capacity, assumed to exist
within an organism, must be depleted or
overwhelmed before toxic effects are •
evident Simply put, for each
mmcarcinogenic endpoint of toxicity
• there irsomekrvr level of exposure
which should have no effect OH humans.
Protection against a toxic chronic effect
for a noncarcinogen is achieved by
keeping exposure levels at or below the
threshold dose.
For noncarcinogenic (threshold}
constituents, the Agency is proposing to
use reference doses (RfDs) as the
starting point for the back calculation
models. A reference does is an estimate
of a lifetime daily exposure of a
substance to the general human
population, which appears to be without
an appreciable risk of deleterious
effects. Historically, this concept was
donated by the term Acceptable Daily
Intake (ADI). However, the term
"acceptable" implies that exceeding the
set level is "unacceptable." Current
scientific understanding does not
consider this demarcation to be rigid,
such that above this level adverse
effects are necessarily evident For brief
periods and for small excursions above
the RfD, adverse effects are unlikely to
occur in most of the population. Several
circumstances can be cited however, in
which particularly sensitive members of
the population suffer adverse responses
well below the level represented by the
RfD. Mast of these special sensitivities
cannot be anticipated before the fact
and must be treated on a case-by-case
basis, likewise, excursion* above the
RfD cannot be anticipated to be without
effect in general and each such case
must be treated individually by
examining factors such as
toxicokinetics, metabolism, nature and
severity of effect shape of the dose-
response curve and nature of the
subpopuJation exposed (Ref. 97).
Historically, ADIs were first used by
the Food and Drug Administration in
1954 as specific guidelines and
recommendations on the use of "safe"
levels of toxic ehpmif.ala for hnmanfl
(Ref. 68}. Since their initial use for food
additives and the ingestion of pesticide
residues by the FDA, ADIs have been
used by other public health agencies in
establishing "safe" levels for toxic
chftminalB in other contexts. The Food
and Agricultural Organization. World
Health Organization and EPA have used
ADIs for establishing pesticide residue
limils in foodstuffs. The National
Academy of Sciences and EPA have
estimated ADIs for purposes of safe
levels of contaminants in drinking water
•(Ref. 3). :
Tte method for estimating the RfD for
noncarcinogenic endpoints of toxicity is
to identify the highest dose of a
substance which causes no statistically
or biologicaRy significant effect in
appropriately conducted tests usually'in
experimental animals. This no-
obaenred-adverae^effect-tevei (NOAEL)
is an estimate of-a population, rather
than individual threshold. The RfD is
derived by dividing the NOAEL by a
suitable scaling or uncertainty factor
(Ref. 97).
NOAELs usually are obtained from
chronic studies or subchronic studies
(e.g., 90 day studies in rodent species).
Other types of lexicological data such
as metabolism and pharmacokineties,
are used to support the judgmental
choice of a particular dose level as the
NOAEL. Confidence in the NOAEL, and
therefore in the RfD, is dependent on the
quality of the experiment, the number
and type of animals tested at each level.
the number and range of dose levels, the
duration of the-study (i.e., chronic versus
subchronic), and the nature of the
biological endpoint measured p.e., the
severity of me observed effects). The
longer the duration of the study, the
smaller is the uncertainty factor applied
to the NOAEL. Selection of the
appropriate uncertainty factor involves
scientific'judgment in the application of
general guidelines (Ref. 99}. The
derivation of RfDs used for establishing
screening levels will be docnmented and
available for public comment at the time
that the specific thresholds are
proposed.
It is •important to note that information
"on exposure levels hi the environment
(e.g., background levels) are not
considered in the development of an
RfD. Rather the RfD reflects the total
theoretical permissible daily human
exposure from all sources, including air,
water, and food. Thus, when analyzing
only one of several possible exposure
routes, it is necessary to "apportion'' or
fractionate the RfD to take into account
other possible exposures. This concept
is-discnssed hi detail later in this unit.
RfDs, where available, were used by
the Agency in the toxicity ranking for
noncarcmogens, as part of the toxicity
ranking scheme which formed, m part,
the basis for the proposed land disposal
restrictions schedule, as published in the
Federal Register of May 31,1985 (50 FR
23250). As indicated in the supporting
documentation for that proposed rule,
RfDs have been calculated for many, but
not all of the noncarcinogenic
constituents for which the Agency will
be establishing screening levels.
Because the RfD value is critical to the
proposed approach for calculating
screening levels, EPA has initiated a
bioassay testing program to fill the
existing data gaps. At a minimum, EPA
will conduct 90-day subchronic studies
in rodents on those hazardous waste
constituents for which few or
inadequate chronic or subchronic
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1628
Federal Register /..Vol. Sli.Mo..9 / Taeaday. January 14, 1986 / Proposed Rules
lexicological data exist All'chemicals
for which RfDs have been calculated
will be re-evaluated by an Agency
workgroup and verified before being
used as the basis for screening levels
(Ref. 121).-
Bioassay testing of compounds has
not been completed for some of the
constituents addressed in today's
proposed rule. Accordingly, insufficient
toxicological data exist for establishing
an RfD. Therefore, in today's proposed
rule EPA is using preliminary data for
isobutanol, ortho-, meta- and para-cresol
and 2,3,4,6-tetrachlorophenol while
appropriate testing continues. EPA
recently proposed a rule under section
8(d) of the Toxic Substances Control Act
to require past, current, and prospective
manufacturers, importers, and
processors of certain compounds for
which data gaps exist to provide EPA
with lists and copies of unpublished
health and safety studies on these
chemicals, as published in the Federal
Register of October 7,1985 (50 FR
40874).
e. Carcinogenic constituents. The use
of the RfD is appropriate only for
noncarcinogenic toxic endpoints. In the
absence of chemical specific
information on mechanism of action or
kinetics, EPA science policy suggests
that no threshold dose exists for •
carcinogens. No matter how small the
dose, some risk remains.
The dose-response assessment for
•carcinogens usually entails an
extrapolation from an experimental high
dose range and observed carcinogenic
effects in an animal bioassay to a dose.
range where there are no experimental
data, by means of a pre-selected dose-
response model. The slope of the dose-
response curve is determined by this
model. EPA's Carcinogen Assessment
Group has estimated the carcinogenic
potency (i.e., the slope of risk versus
exposure) for humans exposed to low
dose levels of carcinogens. These '
potency values indicate the upper 95
percent confidence limit estimate of
excess cancer risk for individuals
experiencing a given exposure over a 70-
year lifetime. In practice, a given dose
multiplied by the slope of the curve
gives an estimate of the number of
individuals estimated to develop cancer
over a lifetime. The slope can be used to
calculate the dose which gives rise to a
ijiven risk level (number of responders,
e.g., one in a million). By specifying the
level of risk (no matter how small) one
can .estimate the lifetime dose
corresponding to it. The dose of a
carcinogen corresponding to a specific
risk is called the Risk Specific Dose
(RSD). To arrive at a starting health
limit for a carcinogen, a risk level or
range of concern must be specified. EPA
proposes to specify a risk level of
concern on a weight-of-evidence basis.
EPA is also considering taking total
population exposure into account in
specifying the acceptable risk level. This
concept is discussed in detail in Unit III.
A.U.
If EPA is unable to operationalize the
consideration of population risk, the
only basis for deviating from the 10"' •
risk level would be the weight of
evidence. Since the 10~* risk level is
conservative, higher levels of the
constituents, could also be acceptable
in the environment. Therefore, the
number set here should not be judged as
general standards that provide clear
demarkations between protective, and
unprotective conditions. There are
numbers that are very clearly within the
protective range. The screening
concentration levels are based on
smaller risks than those EPA has used
as the basis of other regulations that
protect human health and the
environment.
EPA issued Proposed Guidelines for
Carcinogen Risk Assessment, published
in the Federal Register of November 23,
1984 (49 FR 46294), which defined a
scheme to characterize substances
based on the experimental weight of
evidence of carcinogenicity. This
scheme is based on considerations of
the quality and adequacy of the
experimental data and the kinds of
responses induced by a suspect
carcinogen. The classification scheme is
generally an adaptation of a similar
system developed by the International
Agency for Research on Cancer (Ref.
59).
EPA's proposed system comprises five
groups. Group A indicates human
carcinogens based on sufficient
evidence from epidemiological studies
that support a causal association
between human exposure to the
substance and cancer. Group B indicates
probable human carcinogens. The
evidence of human carcinogenicity from
epidemiological studies for substances
within this group ranges from almost
sufficient to inadequate. This group is
subdivided into two categories (Bi and
BJ on the basis of the strength of the
human evidence. Where there is limited •
epidemiologic evidence of
carcinogenicity the carcinogen is
categorized as Bi. Where there is no
evidence or inadequate evidence from
human studies, but sufficient evidence
of carcinogenicity in animals, the
carcinogen is categorized as 62. Group C
comprises possible human carcinogens.
This group includes agents with limited
evidence of animal carcinogenicity. It
includes a wide variety of animal
evidence. Croup D includes agents
which cannot be classified because no
data or insufficient data are available.
Group E includes chemicals for which
there are adequate negative animals
bioassays. This category indicates no
evidence of carcinogenicity in humans.
The Agency regards agents classified
in Group A or B as suitable for
quantitative risk assessment The
suitability of group C agents for
quantitation is best judged on a case-by-
case basis since some Group C agents
do not have a data base of sufficient
quality and quantity to perform a
quantitative carcinogenicity risk
assessment.
s. Since carcinogens differ in the weight
of evidence supporting the hazard
assessment, EPA believes that
establishment of a single across-the-
board risk level is not appropriate. The
Agency proposes to set a reference risk
level as a point of departure, along with
a risk range keyed to the EPA weight of
evidence approach. The dose for known
and probable human carcinogenic
agents (Classes A and B) thus would be
determined at the 10~'risk leveL Choice
of 10~* as the initial risk level of concern
is made on the basis of the following
Agency decisions. Guidance on
response action under the
Comprehensive Environmental
Response, Compensation and Liability
Act of 1980 (CERCLA) requires that the
analysis of cleanup alternatives include
options in the 10~4to 10~7risk range
with at least one alternative utilizing a
10~*risk level (Ref. 109). Options are
often chosen corresponding to a 10~*
risk level. Within the RCRA program the
draft guidance manual for Alternate
Concentration Limits (ACLs), under the
ground water protection program (40
CFR 264.94) identifies 10~aas the point
of departure within a risk range of 10~4
to 10~» (Ref. 98).
Class C carcinogens may be deemed
acceptable at risk levels greater than
10~8 (i.e., HT4 or 10"5). Choice of the
specific risk level depends on the
particular scientific reasons for
classifying the carcinogen as Class C.
This determination will be made on a
case-by-case basis and necessarily will
be guided by the extent of data
available. For those Class C carcinogens
for which there are insufficient data to
perform a quantitative risk assessment,
the dose will be calculated on the basis
of the lowest threshold effect with an
additional uncertainty factor of 10 e.g.,
RfD/10. This approach is similar to that
taken by the Agency in promulgating
and proposing Recommended Maximum
-------
Federal Regfotaf / MBit; 51rNo«ftt/r 'Faewtejiv January 1* 19flS / Proposed RaJe»
Contaminant Levels (RMCL. i.e., health
goals) for certain chemicals in drinking
water published in the Federal Register
of November 13,1985 (50 FR 46880)
(Phase I) and (SO FR 46936); (Phase II).
Some agents appear not to cause
cancer by all routes of exposure {or
entry). Conclusions about route
specificity can be addressed only in
circumstances where adequate data
exist on carcinogenicity for more than
one route of exposure. Where
carcinogenicity findings are available
from only one route of exposure, the
substance is judged to represent a
cancer hazard by all routes, unless it
can be scientifically demonstrated that
the material cannot gain access to target
sites by the alternative routes of
interest. Where the data from one or
more routes are limited, the Agency will
evaluate each case on its merits, placing
particular emphasis on the totality of
scientific evidence.
For a few chemicals (notably metals).
the data base demonstrating that cancer •
is produced by one route of exposure
but tiot by another is substantial and
convincing. An example of compounds
whose carcinogenic responses are
characterized as route-specific are
chromium and some of its salts that
cause cancer by inhalation but
apparently not by other conventional.
routes of entry. Therefore, the Agency ,
will regulate such substances as
carcinogens only by the relevant route
and as noncarcinogens by all other
routes.
f. Use of existing Agency health
standards. EPA, under other statutory
mandates, has investigated the adverse
health effects due to specific chemical
agents with a view towards controlling
exposure through different media.
Health criteria and standards have been
proposed or promulgated for certain
substances in particular media. Since
these have received Agency and public
review and evaluation, EPA is proposing
to use such standards in lieu of the RfDs
or RSDs as the starting point for the
back calculation model. Standards
established for drinking water are
particularly relevant since ground water
is a major pathway of exposure from
waste mismanagement and potentially
could lead to drinking water
contamination. EPA has used the
drinking water standards for 8 metals
and 6 pesticides as the basis of its
Extraction Procedure Toxicity
Characteristic Test. Primary drinking
water standards, i.e., the Maximum
Contaminant Levels (MCLs), are '
enforceable and are based upon health,
treatment technologies, costs and other
feasibility factors such as the
availability: of analyticaI?methods..The
initial step in the standard setting
process-is the identification of
Recommended Maximum Contaminant •
Levels (RMCLs) which are non-
enforceable health limits. The
assessment process for establishing
these health-goals includes evaluation of
the quality and weight-of-evidence of
the supporting toxicological studies,
absorption rates of specific toxicants,
the possibility of nutritionally essential
lower levels for some elements,
existence of route-specific toxicity.
demonstration of other environmental
exposures and finally, the
apportionment of the permissible limit of
constituent into media-specific amounts.
In general, if no compound specific
data are available, the RMCLs for non-
carcinogenic organic chemicals are
established at 20 percent'of the RfD and.
for non-carcinogenic inorganic
substances at 10 percent of the RfD. The
RMCLs for carcinogens in Class A or B
of the Agency's proposed scheme are
established at zero. The RMCLs for
carcinogens in Class C are established
at a non-zero level, determined on a
case-by-case basis. As directed by the
Safe Drinking Water Act, MCLs are toi
be set at levels as close to the RMCLs as
is feasible, taking cost and other factors
into account as mentioned above. MCLs
for carcinogens which have been
promulgated or proposed to date
generally fall into lifetime risk range
10~ 4 to 10"*.
Since a number of the same factors
are being evaluated for each of the
constituents in hazardous wastes.
standards derived under the Safe
Drinking Water Act can be used as the
starting point for the back calculation in
today's proposed rule. EPA recently has
proposed MCLs for eight synthetic
volatile organic chemicals, as published
in the Federal Register of November 13,
1985 (50-FR 46880). After public review
and evaluation EPA will promulgate
final MCLs. Should the final MCLs differ
from the proposed MCLs, EPA will base
its regulatory thresholds on these
revised final MCLs.
As an alternative to die above
approach, EPA is considering using as
RfD or RSD as a starting point for the
back calculation model in lieu of an
MCL Under the apportionment scheme.
discussed below, highly volatile
constituents may contribute less than 20
percent to the ground water route, and
hence EPA may conclude that levels
more stringent than MCL standards are
appropriate. •
SYNTHETIC VOLATILE ORGANIC CHEMICALS
Benzene
Cartxxi tetrachkxxte .'.
1 .4 Dichlorobenzene
1.2 DicNoroettiane
1.1 Dfcfiloroethytene.
1.1.1 TricWoroethane
Tnchkxoethyfene
Vinyl Chloride
Proposed
MCU(ng/()
5
5
750
5
200
5
1
g. Environmental effects levels.
Because the standard for protection
relates to both human health and the
environment, the Agency believes that
effects other than human health, such as
toxicity to aquatic life in surface water,
should be considered in establishing
regulatory thresholds.
It should be noted that the proposed
chronic human health levels in some
instances are likely to be protective of
both human health and the environment
due to the fact that some human toxicity
thresholds are lower than those for non-
human toxicological effects. For
example, this is expected to be the case
for most chlorinated hydrocarbons
including dioxins and chlorinated
solvents. In other instances, the values
protective of human health are
inadequate to protect sensitive
important aquatic species. This is likely
to be true for a few metals.
The Agency has developed and issued
guidelines for deriving ambient Water
Quality Criteria, published in the
Federal Register of November 28,1980
(45 FR 7931B), and has issued a number
of final ambient Water Quality Criteria
to provide protection to aquatic life,
published in the Federal Register of-July
26.1985 (50 FR 30784). These documents
have undergone proposed and final
rulemaking, and full public review. In
addition, the Agency has proposed a
schedule for future development of
additional Water Quality Criteria.
Separate aquatic life criteria have
been developed for fresh water and salt
water organisms because the fate and
effects of some constituents differ in
these two environments. Each criterion
consists of two limits, one for acute
exposures, and one for chronic
exposures. The maximum concentration
is designed to provide protection of
aquatic life from acute toxicity. The
lower concentration is designed to
protect against chronic adverse effects.
The guidelines specify required data
in four categories: acute, chronic, plants.
and bioaccumulation. Other data, (e.g.,
physiological data) are used if pertinent.
All data are evaluated for scientific
acceptability concerning the length of
the test, the age of the organisms, water
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Fad«r«l-R»gtotCT / Vol. St. No. 9 / Tuesday, January 14, 198C / Proposed Rules
quality characteristics, and consistency,
etc.
A minimum of- eight acute tests are
conducted qn a variety of aquatic •
species to derive ultimately the criterion
maximum concentration (CMC). The
CMC is a 1-hour average concentration
that should not be exceeded more than
once every 3 years on average. The
CMC is intended to protect ecosystems
from unacceptable effects due to brief
(short) exposures to high concentration.
A large number of different species is
tested to assure ecological and
' toxicological diversity in the derivation
of the criterion.
Chronic toxicity tests are conducted
to obtain information concerning the
highest constant concentration that
would not unacceptably affect the
survival, growth, or reproduction of a
species. Plant toxicity testing is also
required for the development of- the
criterion since algae are the beginning of
the food chain. Although plant toxicity
is often not as sensitive as animal
toxicity, any effect on plant species may
have significant consequences for
smaller life forms which live on algae.
Finally bioconcentration tests measure
the steady state concentration of
contaminants in muscle and whole body
which may reach human food sources. A
residue value is obtained by dividing
maximum permissible tissue
concentrations by bioconcentration or
bioaccumulation factors. The final
residue value is the lowest of available
residue values. If no maximum
permissible tissue concentration is
available, no residue value can be
obtained.
-The criterion continuous
concentration (CCC) is the highest 4-day
average concentration that should not
cause unacceptable effects on aquatic
organisms and their uses if not exceeded
more than once every 3 years on the
average. The CCC is the lowest of the
Final Chronic Value, the Final Plant
Value, and the Final Residue Value.
In determining acceptable threshold
levels for hazardous waste constituents
in the leachate, the Agency is proposing
to use appropriate health and
environmental contaminant limits,
including Water Quality Criteria that.
have undergone full rulemaking •
procedures. If a water quality criterion
for the constituent of concern is not
available, EPA will seek to identify,
based on other available date, the level
at which the hazardous constituent may
cause harm to the environment.
The Agency solicits comments on this
approach and welcomes additional
information or suggestions that would
be helpful in making regulatory
decisions that consider environmental
risk from land disposal of hazardous
waste.
h. Apportionment of health limits. The
RfD for humans is the maximum daily
dose of a substance in mg/kg/day that
should not be exceeded to assure no
adverse effect over a lifetime of
exposure. If exposure occurs by multiple
routes, some tolerance level-can be
established for each route so that the
sum of exposures by individual routes
does not exceed the reference dose.
The concept of apportionment of a
chemical by medium and by route of
exposure is not new. The first NAS-
National Research Council (NRC) Safe
Drinking Water Committee (Ref. 81)
calculated a suggested-no-adverse-
response level (SNARL) for chronic
exposure to noncarcinogens in drinking
water while incorporating an "arbitrary
assumption" that 20 percent of the
intake of the chemical was from
drinking water. In evaluating
carcinogens, that committee estimated
cancer risks using the assumptions that
tap water exposure was either 1 percent
or 20 percent of the total daily intake.
EPA, in setting RMCLs for chemicals in
drinking water, has followed the
suggestion of the-NRC and selected a
fraction of the RfD (usually 20 percent
for synthetic organic chemicals if no
empirical data suggest some other
fraction). As published in the Federal
Register of November 13,1985 (50 FR
46880).
When determining an RMCL, EPA
considers the contribution from other
sources of exposure such as air and
food. On a case-by-case basis when
sufficient data are available, the RMCL
is determined by subtracting from the
RfD the known contribution of the
constituent in food and air. But such
data are often not available and in these
cases the amount permitted in drinking
water is calculated by an estimation of
the percentage of exposure attributable
to an exposure route; The usual
percentage of drinking water
' contribution hi the absence of known
exposures is 20 percent for synthetic
organic chemicals. For inorganic
chemicals a better data base generally is
available and actual contribution from
other sources can be factored into the
RMCL. Where actual data are sparse,
however, a 10 percent contribution
usually is estimated for drinking water,
since sources other than drinking water
are more likely carriers for inorganics.
Apportionment also has been used in
a risk evaluation procedure used to
evaluate and manage the risks at
specific remedial action sites under the
Superfund program. In this procedure,
concentrations are generally
apportioned equally in environmental
media (e.g., air and water) as an initial
basis for calculating a rate of release. At
times, unequal apportionment is
selected if there are significant cost and
feasibility differences in controlling
exposures via the different pathways.
This approach is appropriate under the
Superfund program since CERLA
provides for a consideration of cost-
effectiveness in its decision process
(Ref. 42).
Many of the chemicals EPA regulates
today are ubiquitous in the environment
and may also be associated with
exposures from other media (e.g., water,
food, air). The Agency is proposing to
limit population exposure to some
fraction (50 percent) of the RfD to reflect
consideration of potential and actual
exposure from all media. Although
available scientific and technical
information as well as past decisions
will be considered in reaching decisions
on the apportionment of RfDs, sufficient
information is not available on the
exposure to chemicals from different
media for different sources and
geographical locations to quantify
reliably the portion of RfDs that should
be allotted for each chemical under
consideration in this rule. As such, an
algorithm for the apportionment of RfDs
has been developed. The Agency
believes this provides a sufficient
margin for other exposures to the
chemical while allotting percentages to
waste management activities that are
meaningful and not unduly restrictive.
-------
Federal: Regjstec /• Vek 51. Np, » /Tuesday,January 14>.198ft../;Eroposed .Rules
1631
However, the Agency is not proposing
to apportion the RSD for carcinogens.
The RSD is estimated by a procedure
which introduces unavoidable
uncertainties and is deliberately.
conservative, so that a difference in
dose of a factor of two is still well
within the margin of uncertainty of the
estimated RSD.
Moreover, for carcinogens, the
determination of risk is the daily dose
averaged over a lifetime. Small
variations around the daily dose have
little effect on the lifetime risk, providing
that the average is not affected. For this
reason, a two-fold reduction in the RSD
is relatively insignificant. For non-
carcinogens, it is possible that not
applying the 50 percent reduction (the
indirect effect of which is to permit an
approximate doubling of the RfD), may
cause the threshold to be exceeded on
some or even many days of exposure. •
Exceeding the threshold for non-
carcinogens may therefore have
significant health consequences for
some individuals. Thus, there is
justification for treating non-carcinogens
"differently from carcinogens with
respect to apportionment.
EPA proposes it apportion reference
doses according, to the scheme shown in
the following Figure 2:
BILLING CODE 6560-50-M
-------
IS32
Federal Register f Vrf. 5*, FS». g / Tuesday., ftmuaty 14.1986 / Proponed Rales
FIGURE 2—FLOW CHART FOR
FRACTIONATION OF Rf D
Determine
total RfD
Is th<
MCL f<
conpc
are an
sr the
aund
-
—yes-
Has EPA
fractionated
RfD into
other media?
-yes-
Fractionate RfD
according to EPA's
scheme
no
no
Do data exist
regarding concentration
of compound in the
various media?
—yes—
MCL water
(100% of total RfD minus the
MCL) fractionate to air and
other media on a case-by-case
basis
no
I
MCL water
(50% of total RfD minus the
MCL) air
Do data exist
regarding concentration of
the compound in the
various media?
fractionate RfD on
a case-by-case basis
no
50% of total RfD—to be fractionated
to air and water using the volatility and
octanol-water constants
MLUHO CODE tSCO-SO C
-------
Register /"VoL a. No. 9. / Tuesday, January 14, 1986 /"Proposed Rules
1633
The Agency will use any previously
estimated percentage apportionment
which it has specified under the Safe
Drinking Water Act to establish the
fraction permitted in water. As
discussed in Unit HLA.l.f, Agency
standards established for drinking water
are considered particularly relevant. If
the Agency, when establishing an MCL,
has fractionated the RfD into other
environmental media, those values will
be used. If the Agency, when
establishing a MCL, has not apportioned
the RfD into other media and if there are
actual data on the concentration of the
compound in those media, the RfD will
be fractionated on a case-by-case basis.
However, if no data are available on
exposure assessment, EPA will use 50
percent of the RfD and subtract from
this SO percent the fraction of the RfD
allotted to water, using the remainder
for air.
For those compounds for which the
Agency has not developed an MCL but
for which data are available on the
distribution of the constituents in air,
water, and food, EPA proposes to
apportion the RfD on a case-by-ease
basis. Where neither an MCL nor data
are available for a compound, EPA will
apportion 50 percent of the total RfD to
air and water according to a simplified
scheme using Henry's Law constant (H,.}
and the octanol-water coefficient (kow)
ta estimate environmental partitioning.
(Henry's Law constant estimates the
ratio of a substance between the vapor
and dissolved state. The ko, estimates
the distribution of a compound between
two liquids: Water and octanol i.e.,
lipid). Each distribution constant (H,.
and kow) is subdivided into two equal
parts according to its range of values as
shown in the following Table 1:
TABLE 1.—RANGES AND CLASSIFICATION OF
HENRY'S LAW CONSTANTS (kH) AND OCTA-
NOL-WATER COEFFICIENTS (lO
High in Air
±K)-»
Low in Air
Low in Wrier
±500
High in Watar
-------
Chemical
CARBON DISULPIDE
CHLOROBENZENE
CRESOLS
1,2-DICHLOROBENZENE
ISOBL7TYL ALCOHOL
METHYL ETHYL KETONE
METHYL CHLOROFORM
NITROBENZENE
PENTACHLOROPHENOL
PYRIDINE
2,3,4,6-TETRACHLOROPHENOL
TOLUENE
1,1,2 - TRICHLORO - 1,2,2 -
TRIFLUOROETHANE
TRI-CHLOROMONOFLUOROMETHANE
2,4,5-TRICHLOROPHENOL
BILLINQ CODE 6560-50-C
DNSTANTS AND OCTANOL-t
Henry's LAW
CONSTANT
(a tin m /rtol)
1.68E-02
3.46E-03
5.05E-06
1.88E-03
1.23E-05
2.61E-05
2.76E-02
2.40E-05
4.62E-06
1.95E-07
)L 4.53E-06
5.93E-03
2 -
9.0QE+00
IANE 8.02E-01
2.84E-05
flATER COEFFICIENTS
RELATIVE
CONCENTRATION
IN AIR
HIGH
HIGH
LOW
HIGH
HIGH
HIGH
HIGH
HIGH
LOW '
LOW
LOW
HIGH
HIGH
HIGH
HIGH
FOR SELECTED HAZARDOUS CONSTITUENTS
OCTANOL-WATER
COEFFICIENT
(•W
1.45E+02
7.41E+02
1.41E+02
3.80E+03
5.50E+00 ;
2.00E+00
3.16E+02
7.94E+01
1.15E+05
4.79E+00
2. 14E+04
6.61E+02
1.26E+03
3.31E+02
7.24E+03
RELATIVE
CONCENTRATION
IN WATER
HIGH
LOW
HIGH
LOW
_
HIGH
HIGH
HIGH
,
HIGH
LOW
HIGH
LOW
LOW
• ' .
LOW
"
HIGH
LOW
M
S.
1
I
a
n
si
Ul
r
'Z
p
-------
Federal Register / Vol. 51. No-. 8= / Tuesday, January 14, 1986 /-Proposed Rules 1635
A relationship between H,. and kHoW
and the distribution between air and
water can be devised using a matrix as
shown in the following Table 3:
TABLE 3.—Matrix To Select Distribution
Between Water and Air Using kow AND kH
Water-
Low
High
Low
Air Water
50:50
Air: Water
20*80
High
Air Water
80:20
Air: Water
• Determined by comparing actual or computed k. and K_
to ranges in Table 1. ,
To construct the matrix EPA assumed
that a compound with equal ranges of
k«w and H,. i.e., high-high or low-low, will
distribute between air and water into
equal parts .(50/50). For compounds that
exhibit a high range for H,. and a low
range for k,,,, EPA assumed that
distribution would be in a ratio of 80 to
20, air to water. As an example, if 50
percent of the total RfD is available for
fractionation into water and air and if
Table 2 indicates a high H,. and a high
kow, the fractionation of the total RfD is
25 percent of the total RfD into each
medium. If the compound exhibits a low
Hc and high kow then 10 percent of the
total RfD will distribute to air and 40
percent to water.
EPA believes that the approach
outlined above is reasonable in light of
the difficulty in obtaining exposure data
for many compounds within the
statutory time limit. The Agency solicits
comment on this general approach.
i. Use of population risk in selecting
starting level. EPA is proposing to base
tHe development of the screening
concentration levels exclusively upon
assessments of the risks to potential
maximum exposed individuals (MEI
risk) posed by the placement of
individual hazardous constituents into
land disposal units. However, the
Agency would prefer to consider
expanding the basis, for these protective
thresholds to include total population
risk as a factor in conjunction with risk
to the maximum exposed individual in
setting screening levels.
The proposal'to augment MEI risk
information with data on risk to the total
exposed population in calculating
screening levels is intended for use only
with carcinogenic constituents, due to
the need to establish acceptable risk
levels for carcinogens in identifying
from their dose response curves the
reference dose, or starting level, from
which the back calculation commences.
Population risk is not proposed as a
factor in determining the reference does
for noncarcinogens.
Whereas MEI risk with respect to
carcinogenic constituents represents the
probability of the realization of an
adverse toxicological effect due to
maximum chronic exposure to a-
hazardous chemical compound,
population risk represents the actual
number of additional cases where the
toxic effect is expected to be realized,
given the number of people estimated to
be chronically exposed to the
compound. For example, an MEI risk of
1X10 ~4 indicates that there is a 1 in
10,000 chance that cancer will develop
in a person who is chronically exposed
to.a specified maximum concentration of
a carcinogenic compound. The
population risk, or incidence,
corresponding to this MEI risk level
depends upon the size of the population
chronically exposed to the compound. If
the total number of people chronically
exposed is 1 million, the expected
number of additional cases of cancer
would be 100. If the total number of
people chronically exposed is 100,000,
the expected number of additional
cancer cases among that population
would be 10. Each of these estimates
assumes, however, that all members of
the exposed population receive the same
dose, or concentration, as the maximum
exposed individual (as would be the
case, fof instance, where the public
drinking water supply is drawn from the
point of maximum contaminant
concentration in the ground water).
As described in Unit HI.A.l.e, the
Agency is proposing to establish an MEI
risk to 10"*as the point of departure in
determining the level of control for all
known and possible carcinogenic
compounds, and to deviate from this
point of departure within an MEI risk
range of 10"6 to 10~4 in determining the
acceptable risk level for individual
compounds based upon the weight of
scientific evidence indicating that the
compound actually is a human
carcinogen. The alternative being
considered by the Agency is to include
estimates of population risk, or
incidence, as an additional factor in
determining each constituent's
appropriate level of control (i.e.,
acceptable MEI risk level) and,
accordingly, in determining the
acceptable concentration of the
contaminant (in air, ground water, and
surface water) from which the threshold
back calculation procedures commence.
Specifically, estimates of the size of the
potentially exposed population for each
constituent would be used in
determining whether the level of control
for that constituent should be increased
or decreased from the MEI reference
risk of 10" * within a range of acceptable
MEI risks between 10"4 to 10" 7-
For example, consider the case of a
known human carcinogenic compound
whose dose-response curve indicates
that chronic human exposure at a
concentration of 1 ppm corresponds to
an MEI risk of 10"7 (i.e., 1 chance in 10
million that the individual will develop
cancer), that an exposure concentration
of 10 ppm corresponds to an MEI risk of
10"8, and that exposure at 1,000 ppm
corresponds to an MEI risk of 10~4 (i.e., 1
chance in 10,000 of developing cancer).
In this example, EPA is considering
using population risk in the following
way: if a very large number of people is
believed to be potentially exposed to ,
releases of the contaminant from land
disposal units, such that the number of
additional cases of cancer expected to
• result from such exposure is relatively
large, the level of risk-related control for
the compound may be increased from
10~6 to as low as 10~7, and a
corresponding concentration of 1 ppm
would be used as the starting point in
the back calculation to determine the
screening concentration level for the
constituent. If the size of the potentially
exposed population is estimated not to
be very large, the point of departure MEI
risk level of 10"8 would remain as the
acceptable risk level for the compound
and a concentration of 10 ppm would be
use to commence the back calculation.
If, however, a smaller number of people
is believed to be potentially exposed to
releases of the contaminant from land
disposal units, such that the incidence of
cancer is expected to be small from such
exposure, EPA would consider
increasing the acceptable MEI risk level
from the 10~s point of departure to an
MEI risk level of 10"5 or 10"4. In this
example, adding population risk as a
factor to be considered in determining
the acceptable MEI risk level for the
compound could result in back-
calculated screening .concentrations or
protective levels, that vary by three
orders of magnitude (i.e., one
thousandfold) for small versus large
populations.
There are advantages to including
population risk as a factor in developing
the screening levels concentrations.
First, population risk provides a
valuable piece of information in making
a risk management decision on the
acceptable MEI risk level, and the
corresponding back-calculated
concentration. In order to assure that
screening concentration standards are
truly protective of human health and the
environment, EPA must assure not only
protection of any exposed individual.
-------
Federal Register-/ Vol.,51. No. & / Tuesday. January t4. 1986 / Proposed Rules
but must also ensure that there will not
be aa unacceptable incidence of health.,
effects in cases where large numbers of
people may be exposed. Population risk
allows the Agency to choose regulatory
levels that will protect individuals and
groups of exposed people.
Second, in accounting for total
population in making regulatory
decisions under the land disposal
restrictions program, EPA will be
proceeding in a manner that is
consistent with certain Agency
decisions in the air, water, and toxics
programs. For example, decisions under
section 112 of the Clean Air Act (CAA)
consider risks to both individuals and
exposed populations. Likewise.
incidence is one of the factors that
influence the National Ambient Air
Quality Standards (under sections 108
and 109 of the CAA, and section 4(fJ
decisions under the Toxic Substances
Control Act (TSCA)). Also., the Agency
is.committed:to evaluating population
exposure as one of the major.factora .
needed to assure efficient risk
reductions in new regulations [Ref. 120).
Section 4{0"qf.TSCA [a a priority
setting mechanism by which EPA '
identifies chemicals that require
expedited regulatory consideration
under section 7(f) of TSCA. In order to
assign priority consideration under
section4(f). EPA is directed by statute to
decide whether there may be a
reasonable basis to conclude that a
^'significant risk of serious harm" or a
"significant risk of widespread harm" is
or will be presented. The "significant
risk of serious harm" standard is
interpreted to cover situations in which
persons are exposed to particularly high
risks. The "significant risk of
widespread harm" standard is
interpreted to cover situations in which -
the risks to exposed individuals are
somewhat lower, but the number of
persons exposed is very large.
Accordingly, factors considered by EPA
to be relevant in section 4(f) priority
setting decisions have included: the
chemical's potential to cause'any of
three designated health effects; the
likelihood of harmful exposure levels;
and. the number of persons exposed.
Section 112 of the Clean Air Act
requires EPA to identify hazardous air
pollutants and to develop appropriate
national emissions standards for various
types of sources (e.g., fugitive emissions,
routine emissions, etc.). Under section
112, a finding that emissions of a
chemical from specific types of sources
pose significant cancer risks warrants
EPA's establishment of national
emission standards for those sources.
Accordingly, factors considered by EPA
to be-relevant in section 112
determinations include: the'human
carcinogenicity of the chemical; the
magnitude of the emissions of the
chemical from specific types of sources:
the ambient concentrations of the
chemical in the vicinity of the emission
sources; the proximity of people to these
sources; the estimated maximum
individual risks posed by emissions of
the chemical; the estimated incidence of
cancer in the exposed population;
projected increases in emissions of the
chemical from new sources of the same
type; estimations of the reductions in
emissions and health risks that can be
achieved; and the uncertainties
associated with the quantitative risk
estimates (including effects of
concurrent exposures to other
substances and to other emissions of the
chemical from other types of sources).
Section 109 of the. Clean Air Act
requires EPA to establish national
ambient air quality standards for three
classes of chemicals (excluding those
chemicals identified as hazardous air '
pollutants under section 112), bas:ed
upon findings that they may cause or
contribute to air pollution according to
criteria outlined in section 108. In
establishing such standards. EPA is
required to provide an "adequate margin
of safety" so as to prevent pollution
levels that have been demonstrated to
be harmful and also to prevent lower
pollution levels that may pose
unacceptable risk of harm, even if that
risk is not precisely identified as to
nature or degree. In selecting a standard
that provides an adequate margin of
safety, EPA has considered such factors
as the nature and severity, of the health
effects involved, the size of the sensitive
population(s) at risk, and the kind and
degree of the uncertainties that must be
addressed.
The Agency also recognizes a number
of disadvantages associated with
including population risk as a factor in
developing the screening concentration
standards. EPA is concerned that it may
not be able to assign different
potentially exposed populations to
different hazardous constituents or
chemical compounds, a crucial element
in the use of population risk as a factor
for determining the acceptable MEI risk
for each individual compound.
• This concern rests upon two primary
factors. The first, which is practicalin
nature, is that the Agency's existing
data on hazardous waste management
practices are limited with respect to the
location of individual hazardous
constituents at specific land disposal
facilities. EPA's current sources of data
on the more than 1,500 concurrently
operating land disposal facilities include
Part A and B permit applications and
biennial reports. While these data
sources do provide information on the
wastes managed at facilities, by EPA
waste code, they provide little
information on the types of hazardous
constituents contained in those wastes.
Thus. EPA is concerned that it lacks the
type of data that would be required to
defend the assignment of different
population distributions to different
constituents.
The second reason for EPA's concern
is that the Agency recognizes that
hazardous wastes and hazardous
constituents are extremely mobile.
Today's location patterns for individual
hazardous constituents across the more
than 1.500 RCRA land disposal sites
may not be adequately represented by
their patterns in 1981 or even 1983. -
Location' patterns in 1981 or 1983 are
even less likely to represent disposal
facility location patterns in 1990, the
year 2000,:and beyond. Waste shifts
occur as'capacities are used up, as the
economics of transportation and
comrijercial waste management
practices continue to evolve, "as
industries change the location of their
production process, and as new
industries develop.
In addition, the Agency is concerned
that including population risk as a factor
in determining acceptable MEI risk
levels in developing the screening
concentration levels may complicate the
decision-making process required to
establish section 3004(m) treatment
standards within the statutory
timeframes and may create
inconsistency over the many hundreds
of such decisions that must be made.
The Agency has not, to date, established
any formal decision rules for
determining acceptable numbers of
additional cancer cases or for weighing
MEI risk against population risks. The
development of such decision rules is
expected to be time consuming. The
Agency is concerned that in the absence
of such decision rules, its development
of the screening concentration levels
and associated section 3004(m)
treatment standards may be
inconsistent across the more than 350
constituents for which they must be
developed.
Accordingly, EPA specifically
requests public comment on the
inclusion of population risk as a factor
in developing the screening
concentration levels, on specific aspects
of the approach suggested for
implementing this concept (described in
detail in the remainder of this unit), on
other approaches that the Agency
-------
Federal Register / Vot. 51, .No» & / Tues^gfejanuaiy 14, 198O / Proposed Rules
should consider for implementing this
concept, and on the nature, sources, and
availability of data required t& consider
population risk in addition to MEI risk.
The remaining parts of this unit
describe one approach the Agency is
considering for including.population risk
(incidencepas a factor in setting the
screening levels. Three major steps for
assessing incidence are listed. A
detailed approach for each step is
offered. Potential sources of data—both
the extent and quality—are described.
Assumptions necessary to complete the
evaluation are listed.
STEP 1: Calculate population risk
estimates. Population risk estimates can
be calculated in a similar manner for air,
surface water, and ground water routes
•of exposure. To do so, the Agency would
first gather population counts for areas
surrounding existing hazardous waste
disposal facilities. Where exposure
through ground water and surface water
is considered, the appropriate measure
is the number of persons whose drinking
water is supplied by ground water and
surface water .potentially affected by
disposal facilities, as well as the number
of persons consuming contaminated fish.
EPA would consider populations living
within a 50 km radius when assessing
incidence due to exposure through air.
Fifty kilometers is generally the largest
distance that is used to model
dispersion and exposure to airborne
pollutants, and is also the distance used
in the comparative risk assessments
described in Unit III.C.
Using the address of each facility
seeking a permit under RCRA, EPA can
estimate the current surrounding
populations using the most recent
census data. Ground water usage data
can be obtained from the Federal
Reporting Data System (FRDS)
maintained by EPA's Office of Drinking
Water. This source contains records of
all wells used as public water supplies.'
A major source of private well use data
is the 1980 Census. The Census contains
information on the water supply source
for each U.S. household. The Agency is
presently adding these data to the FRDS
data base. In a related effort, EPA is
matching water supply source data with
the location of hazardous waste and
other facilities. When supplemented
with data gathered from Part B permit
applications and from recent EPA visits
and inspections of RCRA interim stajus
facilities, the Agency may be able to
estimate accurately the number of
potentially exposed people currently
near RCRA land disposal facilities. .
Next, the Agency could develop a
distribution that reflects the relative
frequency at which a given number of
people may be exposed to releases from
each hazardous waste disposal unit.
Finally, current population risk would
be estimated by multiplying the risk to
the maximum exposed individual
chosen as the basis of the Health-based
level by the number of exposed people.
Note that for exposure through ground
water, assuming steady-state exposure,
risk to the maximum exposed individual
equals risk to the "average" exposed
individual. This is due to two factors:
concentration at the well is estimated to
be constant in time; and, since all
consumers drink from the same well,
there is no differential exposure.
STEP 2: Estimate future population
exposure. These incidence estimates
could then be adjusted for population
change patterns. One approach would
be to evaluate census data for each site
for the past 40 years to determine
population density and ground water
use trends. The following Figure 3
illustrates population change trends for
6 major U.S. cities over the past 40-
years:
BIUJNO CODE «SM-M-M
-------
CO
z
LJ
O
6
*
O
3
(7
in
O
w
c
O
w
0
1940
Figure 3
POPULATION DENSITY OF
SELECTED CITIES OVER TIME
t
195O
New York
q Boston
1960
* Philadelphia
° Son Kroncisco
1970 i960
A St Louis
x Washington. DC
BU.LINQ CODE 6WO-50-C
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Federal Register / Vol. 51, No. 9 / Tuesday, January 14, 1980 / Proposed Rules
1633
EPA could adjust current populations.
at benchmark times in the future .
reflecting these trends. Data seem to
indicate that the most densely populated
and biggest cities are becoming less
densely populated over time. For
example. New York City reached the
largest U.S. population density ever in
1970. New York's population density has
been declining since that time. Instead
of assuming that current trends
continue, EPA may need to limit the
decline in density using informed
judgment. Otherwise population would
shrink to nothing over a several hundred
year time horizon. In a similar fashion,
the Agency could cap the density of any
rapidly growing smaller community,
perhaps to that of New York City in
1970, to prevent estimation of densities
growing so large that the entire
population of the country could fit into a
single city. Then, at each benchmark
time, EPA could generate the population
distribution for all current sites, and use
this distribution to estimate potential
future incidence. The Agency notes,
however, that this process may not
account for the development of entirely
new communities, where previously
none had existed, as in the case of the
establishment of planned communities
or the creation of new housing
developments in rural areas.
STEP 3: Incorporate population risk
into the procedures to develop the
screening concentration levels.-fhe
final step is to include population risk
(incidence) as a factor in determining
the screening concentration levels. First,
a reference dose based on the starting
point of 10" 8 MEI risk for carcinogens
would be used as the starting levels to
back calculate a corresponding
screening concentration level using the
back calculation models. The population
risk corresponding to this individual risk
would be estimated by multiplying
individual risk by the exposed
population (e.g., for an MEI risk of 10~*;
and an exposed population of 1,000,000,
the population, is l
-------
1640
Fedarat Register / Vol. 51. No. 9 / Tuesday. January 14, 1986 / Proposed Rirfes
accept the particular constituent under
evaluation. Thus, individual constituents
will have population risk estimates
based on relevant population
distributions. The Agency is concerned.
however, that these population
distributions may not reflect future or
even current population distributions.
since the data from which they would be
developed are for 1980 and 1981. and
due to the fact that hazardous wastes
are easily transported. Furthermore, the
Agency is concerned that many
hazardous constituents already appear
at such a broad variety of facilities that
they will exhibit essentially the same.
location pattern with respect to
potentially exposed population
distributions. Accordingly, for most
constituents EPA would be unable to
specify accurate specific populations for
use in incidence calculations. In these
cases, the Agency would use population
data from the entire set of hazardous
waste land disposal units.
The preceding discussion assumes
that waste distribution patterns among
existing disposal facilities will remain
constant. Once permits have been
issued, facilities must obtain permit
modifications to accept new wastes. To
the extent that waste disposal patterns
shift from on-site to commercial
facilities, the Agency could include
these effects in a sensitivity analysis to
the incidence calculation. Otherwise,
limitations in EPA's ability to account
for this phenomenon present a
weakness in its analysis of population
risk. Comments on the importance of
waste shifts, and. in particular, on the .
impact of the absence of any regulatory
controls on the location of waste
constituents in the calculation of
incidence, and suggestions for •
addressing this problem are requested.
2. Ground Water Back Calculation
Procedure
a. Introduction. Under the framework
presented in this proposal, EPA will
establish screening concentration levels
for individual hazardous constituents
contained in hazardous wastes. These
levels are expressed as maximum
acceptable concentrations for individual
constituents in extracts of wastes. EPA
has developed a quantitative modeling
procedure to evaluate potential impacts
on ground water and establish screening
levels for this medium. The proposed
ground water screening procedure
involves a back calculation from a point
of potential exposure at a specified
distance directly downgradient from a
land disposal unit to a point of release
from a land disposal unit using a fate
and transport model (Ref. 2).
This procedure considers a number of
factors including:
i. The toxicity of constituents in the
waste.
ii. The mobility of constituents in the
waste.
iii. The persistence of constituents in
the waste.
iv. The long-term uncertainties
associated with land disposal. The
toxicity of a constituent is considered in
the procedure by specifying a reference
dose (health effect level) at the point of
measurement and back calculating the
maximum acceptable leachate
concentration that will not exceed the
specified level
The mobility of constituents is
considered in the procedure through the
actual leachate values and, for organics,
through incorporation of sorption as a
delay mechanism to travel in the ground
water model. The inclusion of sorption
in, the ground water model acts to delay
the time of arrival at the measurement
point and is important only for organic
constituents which degrade.
The persistence of constituents is
incorporated into the ground water
model for organics by considering
hydrolysis. Metals do not degrade, so no
degradation is assumed. However,
speciation of metals in ground water is
considered through incorporation of the
MINTEQ speciation model (Ref. 2) in the
procedure.
The long-term uncertainty of land
disposal is considered by evaluating the
long-term performance of engineered
land disposal units. Specifically, the
model assesses the long-term chemical
flux or leaching to the ground water
from RCRA Sabtitle C land disposal
units under certain assumed conditions.
This leaching process depends on
climatic conditions, soils, and the long-
term performance of the engineered unit.
EPA developed long-term quantitative
estimates of leaching rates using the
HELPmodel.
In sum, the ground water back
calculation procedure involves the
application/of three model components:
the HELP model which addresses
performance of engineered controls, the
fate and transport model (EPASMOD)
which models the behavior of
constituents in the ground water
environment, and the MINTEQ model
which models the behavior of metals in
the ground water environment (Ref. 2).
These major components of the ground
water screening procedure are described
in more detail below.
b. The HELPmodel. The HELP model
was developed by EPA specifically to
facilitate estimation of the amount of
runoff, drainage, and leachate that may
be expected to result from a hazardous
waste landfill. In general the HELP
model predicts the water balance by
performing a mass balance between
flow into various components of a
landfill and water leaving these
components. The model uses
climatologic, soils, and design data to
produce daily estimates of water
movement across, into, through, and out
of landfills. The HELP model conducts
water balance computations on a daily •
time step and accounts for the effects of
runoff, surface evaporation, infiltration,
evapotranspiration, subsurface lateral
drainage, and percolation. The model
contains default data which can be used
if alternative data are not available.
Data requirements and inputs to the
model are discussed below.
i. Climatologic data. The HELP mode!
contains a climatologic data base for 102
reporting stations located in the U.S.
The data base consists of 5 consecutive
years of daily precipitation values in
inches, one set of mean monthly
temperatures, mean monthly insolation.
and leaf area indices and winter cover
factors. The model allows manual mpu.
of all or any part of the above input
variables. The maximum data base size
allowed by the model is 20 years of
record. Because theT)ui!t-in data files
are not representative of climatic
conditions in the U.S., the Agency •
developed representative climatic
conditions for the U.S., then selected
appropriate default climatic files from
the model for further analysis.
To develop representative national
climatologic conditions, precipitation
and evaporation data from the National
Oceanic and Atmospheric
Administration were used to identify
ranges of climatic conditions that are
encountered hi the 48 contiguous States.
Using these distributions, the Agency
selected six precipitation ranges and
three evapotranspiration conditions as
representative of the U.S. Thus, a total
of 18 climatic conditions were identified
for developing national distributions of
leaching rates. A reporting station of
climatic data was selected in each of
these 18 areas from the 102 cities
included in the HELP model data base.
Cities selected represent the median
range for each of the 18 climatic
conditions. For each city selected, the 5
years of climatic data in the model were
accessed and used to develop national
leaching rates. The Agency believes thai
the selected cities and associated
climatic data are representative of
climatic conditions throughout the U.S.
and are appropriate for use in this
analysis.
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jgedetaLgqgjsto / VoL 51, No. 9j "Tuesday,: January 14. 1988 / Proposed Rales
Long-term chemical flux fa ground
water from land disposal units occurs as
a result of precipitation (water)
percolating through the waste and
dissolving chemicals into this liquid.
Precipitation in excess of losses due to
surface runoff and evapotranspiration
will result in net infiltration or deep
percolation to soils below the root zone.
The Agency considers net infiltration to
be comparable to the long-term chemical
flux at land disposal units. Thus, since
EPA assumes that the land disposal unit
is completely saturated at the end of the
post-closure care period, if 1 inch of
water is estimated to infiltrate into the
unit, 1 inch of leachate will be released
from the unit.
ii. Facility design. The goal of the
design standards for hazardous waste
land disposal units is to minimize the
formation and migration of leachate to
the ground water environment The
Agency assumes that land disposal units
will contain hazardous constituents that
will be capable of migrating out of the
units during the active life, dosure, and
post-closure period. The goal of the
liners and leachate detection/collection
systems is to minimize the rate and
volume of leachate and constituent
migration so as to prevent ground water
contamination during the operating,
closure and post-dosure care periods
(the latter is normally assumed to be 30
years). During and after the post-closure
care period, the final cover is required to
minimize infiltration into the closed unit
Data describing the physical design of
the land disposal unit must be specified
as inputs to the HELP model. The major
design conditions which must be
specified include cover and liner
configuration (e.g^ slope, soil types,
barrier layer materials, vertical
percolation layer and lateral drainage
layers), type of vegetative cover, and
depth of root zone. Specification of
these design conditions was based on
an evaluation of the requirements for
RCRA Subtitle C land disposal units.
As noted earlier, the model addresses
four major methods; of land disposal, Le^
surface impoundments, landfills, waste
piles, and land treatment (underground
injection wells are to be addressed
separately}. Eventually, the Agency
hopes to develop an additional
component to the ground water model
which specifically addresses land
treatment units.
The Agency based its evaluation of
the long-term performance of engineered
controls at these units on several key
assumptions. First, the Agency assumes
that there will be no chemical flux
resulting in ground water contamination
during the active life, closure, and post-
closure care periods at these units. This
assumption is based on EPA's belief that
the liner and leachate collection systems
required by the new section 3004(o),
together with corrective action
requirements, will assure that hazardous
constituents will not migrate to the
ground water in unacceptable
concentrations during this time period.
Second, the Agency assumes that the
engineering controls to be evaluated by
the model, i.e., those remaining in place
after the post-closure care period, are
those controls applicable to a closed
landfill.1* The assumption is founded on
the requirements of the existing
regulations which specify that surface
impoundments and waste piles must
either remove or decontaminate all
hazardous wastes at closure, or close in
conformance with landfill closure
standards (40 CFR 284,228 and 284.258).
Third, the Agency assumes that the
teachability of the waste is not
diminished during the active life.
closure, and post-closure care periods.
Fourth, the Agency assumes no
degradation of hazardous constituents
through the postclosure care period.
Fifth, the Agency assumes that
infiltration resulting from precipitation
is the major mechanism responsible for
mobilizing wastes in the unit Finally.
the Agency assumes that, beginning
immediately after the end of the post-
closure care period, the engineering
controls applicable to a closed landfill
will have degenerated to the point that
the primary engineered mechanism for
controlling chemical flux through the
unit will be the clay'component of the
cap. This is a worst-case assumption
because it presumes the flexible
membrane liners will cease to function
immediately at the end of the post-
closure care period. This last
assumption is explored in more derail
below.
The engineering components of a
closed landfill include multi-layered
cover and liner systems consisting of
drainage layers, flexibile membrane
liners and soil barriers. Performance of
engineered units m the short term p.e.,
during the operating life, closure, and
post-closure care periods) depends on
appropriate design, material selection
and specification, construction, waste
screening, inspection, maintenance, and .
monitoring. In the long term (i.e., beyond
the 30-year post-closure care period) the
performance characteristics of cover
10 As wilt be explained later, the mxU assumes
that the controls remaining in place after the post-
closure care period will consist only of the day
component* of the cap and finer systems. AB
synthetic components, as weH at the lucbat*
detection/collection tytiem. an anuraed not to
affect the chemical flux following the post-cloiure
care period.
and finer systems can be expected to
change. Components such as flexible
membrane liners may undergo dramatic
changes in performance while other
components, such as clay liner, may
undergo more limited change hi
performance. The effect these changes
have on component and unit
performance will control the chemical
flux rate.
The principal change affecting this
long-term chemical flux rate is expected
to be the degradation of the flexible
membrane liners to a point where they
are no longer effective in controlling
leachate movement Additionally, the
leachate detection/collection systems
that remove leachate from the unit are
assumed not to be operating after the 30-
year post-closure care period because
the regulations generally do not require
operation after this 30-year period. The
clay layers are expected to have greater
hydraulic conductivity as a result of
geologic change and exposure to
chemicals.
Practical experience with the
performance of flexible membrane liners
as barriers to leachate Qowis limited to
- a few decades, (Limited data suggest
that the long-term service life of flexible
membrane liners may extend over
several decades and possibly as long as
100 years.) Since EPA's long-term
analysis of engineering controls
considers performance over hundreds of
years and the service life of flexible
membrane liners is estimated to be a
fraction of this period, the effectiveness
of flexible membrane liners to control
leaching rates after the end of the post-
closure care period is assumed to be
equal or less than that of day barriers.
The nse of day soils in cover or liner
systems is subject to both geologic
weathering and alteration of the clay
soil structure on exposure to chemicals.
The extent of alteration is controlled by
factors such as type of day mineral,
waste constituent and constituent
concentration. Naturally occurring clay
soils near the ground surface can be
considered representative of the extent
of geologic weathering to which clay
barriers in RCRA Subtitle C facilities
will be exposed. A survey of day soils
across the U.S. radicates ranges of
hydraulic conductivity from 1.4 X 10~c
to 4.3 X 10 "5 cm/sec for soils at depths
of 30 to SO inches (Ref. 40). The Agency
assumed that natural days compacted
to achieve the required hydraulic
conductivity of 10"' cm/sec will have
long-term hydraulic conductivities
similar to the upper limit for hydraulic
conductivity found in geologically
weathered naturally occurring clays.
Additionally, evidence indicates that the
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Federal Register / Vol. 51, No. 9 / Tuesday, January 14, 1986 / Proposed Rules
hydraulic conductivities of clay soils
may increase by a factor of ,100 upon
exposure to waste constituents (Ref. 2).
While much of the current knowledge of
chemical interactions with clay is based
on laboratory studies, similar effects are
expected under field conditions. A
hydraulic conductivity range of 5 X 10~6
lo 5 X 10~7 cm/sec is assumed to be a
reasonable estimate of the long-term
performance of clay barriers.
Based on the above evaluation, the
Agency selected the following facility
design conditions for a RCRA Subtitle C
landfill for analysis in the HELP model:
(A) A cap consisting of:
(1) Two feet of cover soil consisting of
a loam texture and good grass stand.
(2) One foot drainage layer at 2
percent slope to a free drain at the toe of
the slope.
(3) Root zone of 3 feet.
(4) Clay cover'of 3 feet with a long-
, tgerm hydraulic conductivity of 1 x 10"s
cm/sec;ll
(B) A liner consisting of:
(1) A flexible membrane liner.
(2) A clay liner.
However." as previously discussed, the
long-term effectiveness of flexible
membrane liners is assumed to be equal
to or less than that of the clay liner. The
clay layer in the bottom liner system is
assumed to be subject to similar
conditions as the clay layer in the cover
system and is also exposed to chemicals
leaching from the waste. Therefore, the
hydraulic conductivity of the bottom
clay liner is expected to be equal to or
greater than the clay layer in the cover.
and to have no effect on the chemical
flux througlrthe unit
Leaching (flux) rates were estimated
for RCRA Subtitle C landfills using the
HELP model for the climatic conditions
and design specifications specified
above. Leaching rates were estimated
for the 18 climatologic conditions. As a
whole, this set of conditions is
considered representative of the entire
U.S. These chemical flux rates were
incorporated into the steady-state
advective dispersive transport model
through mass balance principles by
relating the areal flux of leachate
through a land disposal unit: to the
nature of the leachate after it is mixed in
the aquifer. This mechanism is
described later in this unit EPA solicits
public comment on the above-described
application of the HELP model to
simulate the containment provided at
11 Although the regulations require a synthetic
liner In the cap if a synthetic liner is included in any
liner under the waste, the presence of a synthetic
liner component in the cap is ignored for purposes
of this anaylsla because synthetic liners are
presumed lo provide equal or less control than clay
liners.
certain RCRA Subtitle C facilities. In
particular, the Agency requests
comment on the various assumptions
articulated in the foregoing discussion.
c. Fate and transport model. The fate
and transport of constituents in the
ground water to a measurement point
directly downgradient from a land
disposal unit is approximated through; a
three-dimensional steady-state
advective dispersive model. The
mathematical techniques employed in
the model are based upon analytical
solution procedures well established in
the scientific literature.
The proposed ground water model
accounts for most of the major physical
and chemical processes known to
influence movement and
transformations qf chemicals in simple.
homogeneous and isotropic porous
media under steady flow conditions.
The mechanisms considered include
advection, hydrodynamic dispersion in
the longitudinal, lateral, and vertical
dimensions, absorption, and chemical
degradation. Mechanisms not
considered in the model include
biodegradation and dilution of
constituents in drinking wells due to
well drawdown. The Agency requests
comment on an alternative approach
which would account for dilution caused
by well drawdown. EPA requests
submission of data on constituent
dilution rates typically caused by well
drawdown to assist its consideration of
this matter by commentators concerned
about this issue.
d. Model assumptions. The analytical
solution described below is based on a
number of key assumptions pertaining to
the features of ground water flow,
properties of the porous medium and the
behavior of hazardous wastes in ground
water. These assumptions include the
following:
i. Saturated soil conditions (no
attenuation of chemicals in the
unsaturated zone).
ii.-Flbw regions of infinite extent in
the longitudinal direction, semi-infinite
extent in the lateral direction, and finite
in the vertical direction.
iii. All aquifer properties are
homogeneous and isotropic and of
constant thickness.
• iv. Ground water flow is uniform and
continuous, in direction and velocity.
v. Degradation is limited to hydrolysis
and byproducts of hydrolysis are
assumed to be nonhazardous.
vi. Sorption behaves linearly.
vii. Infinite source—supplies a
constant mass flux rate.
viii. Precipitation recharge supplies
water to the aquifer.
ix. The ground water is initially free of
contamination.
x. The receptor-well is directly in line
with the source and the ground water
flow.-
xi. The receptor well is located 500 -
feet from the unit.
The effect of the first assumption is to
presume that a waste is placed directly
at the top of the saturated zone. Based
on a survey of 163 Part B permit
applications available within EPA as of
October 1984, the Agency determined
this assumption to be reasonable
because approximately 10 percent of the
land disposal units in the survey
extended to the top or within a few feet
of an aquifer. This worst-case
assumption predicts that no attenuation
occurs during the migration of
constituents in leachates to .the
underlying aquifer. The Agency believes
this conservative assumption, like the
other conservative assumptions
included in this analysis, is appropriate
for the reasons noted in Unit III.A. The
second assumption of infinite and semi-
infinite flow regions in the longitudinal
and lateral direction respectively is
appropriate for all simplified analytical
ground water flow models. However,
aquifers have a finite areal extent and
could be confined by impermeable
layers. If an aquifer is confined by an
impermeable layer, this assumption may
underestimate or overestimate
downgradient contaminant
concentrations.
The assumption of homogeneous and
isotropic aquifer properties is rarely
encountered in the field, but the
availability of data and the generic
nature of this analysis require the use of
. a homogeneous and isotropic
approximation. Also, this assumption is
usually employed if the solution of the
problem is obtained-by analytical
techniques.
The fourth assumption of uniform flow
velocity presumes that the water volume
entering from the source isnot large
enough to affect the natural ground
water gradient. This assumption is
appropriate for simplified analytical
solutions. In situations where the ground
water flow system contains pumping or
injection wells, drastic changes in the
velocity distribution will occur. Under
this situation, the steady-state
downgradient contaminant
concentrations may be overestimated or
underestimated.
Degradation limited to hydrolysis, the
fifth assumption, is the only mechanism
for transformation considered in the.
proposed model. While other
transformation mechanisms such as
biodegradation and oxidation are also
important, the Agency's present
understanding of these mechanisms'
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Federal Register / Vol. si. No. 9 / Tuesday, January 14, 1996 / Proposed
IffCT
does not yet permit a kinetic
representation of these processes within
the system modeled. The effects,
relative importance, and interactions of
these processes in the ground water
environment are not well understood
and are under investigation.
In general, all transformations are
dependent upon both the chemical
constituent and the prevailing
environmental properties. For
hydrolysis, ground water pH and
temperature must be known. The
Agency's analysis to date has identified
more than 20,000 measurements for pH
and temperature from which distribution
functions can be assigned for purposes
of evaluating variation and uncertainty.
Similar data describing microbial
populations, metabolizable carbon
sources, etc., are not generally available.
The Agency believes that with this
limited understanding of the factors
influencing biodegradation and
oxidation in the ground water
environment, these processes cannot be
included in the proposed ground water
screening model. By including only
hydrolysis in the model, the Agency is
being conservative. The Agency
requests comment on an alternative
modeling approach which would
directly consider these phenomena.
Accordingly, the Agency is interested in
receiving any available data on
constituent biodegradation, oxidation,
and reduction rates in ground Water.
The sixth assumption, sorption
behaves linearly, specifies that sorption
is instantaneous, of local equilibrium,
and completely reversible. Sorption
reactions for contaminants in ground
water are viewed as being rapid relative
to the flow velocity; and the amount of
contaminant sorbed is commonly a
function of concentration in the solution.
At constant temperature and moderate
concentrations, the relationship between
the absorbed concentration and
dissolved concentration is approximated
by equilibrium isotherms. Based on this
relationship, the Agency believes this
assumption to be reasonable.
The seventh assumption of an infinite
source presumes that the mass of a
constituent in a land disposal unit is
physically realistic to justify this
conservative assumption. The Agency
has evaluated the significance of this
assumption and its impact on the
outcomes of the ground water modeling
procedure. The evaluation demonstrates
that the mass required, to justify this
assumption is quite reasonable and
physically realistic (Ref. 2).
The assumption of dilution of the
contaminant plume by precipitation
recharge accounts for the impact of
water that infiltrates through the soil
layers and enters the aquifer. The
Agency believes it is appropriate to
incorporate-precipitation recharge in the
ground water model because it is a
process known to occur in the
environment and representative values
can be developed for the contiguous 48
States using the HELP model.
The assumption emplacement of a
well in the exact position to receive the
highest concentration of a contaminant
represents a worst case. The Agency
believes this assumption is appropriate
for use in the generic screening
procedure because some drinking water
wells may be directly in line with RCRA
Subtitle C land disposal units and
because it is impossible to determine the
extent to which wells are not located
directly in the path of potential plumes.
Finally, the back calculation is based
on the assumption that the receptor well
is located 500 feet from the unit. Existing
RCRA regulations under § § 264.120 and
265.120 require owners of disposal
facilities to record a notation on the
deed for the property (or other
instruments examined during title
searches), that the land has been used to
manage hazardous waste. Since this will
provide notice to subsequent owners of
the property of the land's prior use, it
may be reasonable to assume that no
one would extract water for human
consumption from within the property
boundary. Accordingly, EPA could
conclude that the area of effective
control extends to the property
boundary* A more conservative
approach to defining the area of
effective control is the waste
management boundary—an imaginary
line circumscribing the regulated units at
the facility or, even more conservatively,
the edge of the disposal unit. As
described in further detail in Unit III.G
of this preamble, on a site-specific basis,
the area of effective control may extend
beyond the unit, waste management
area, or in limited circumstances, the
property boundary.
In an attempt to quantify a distance
representing the potential point of
human exposure on a generic basis, the
Agency did a survey of 163 Part B
hazardous waste land disposal permit
(1)
d'c
Where:
x, y, z=spatial coordinates in the
longitudinal lateral and vertical
directions, respectively, (m)
applications available to EPA as of
October 1984. (This information is
currently being updated to include
permit applications received since
October 1984.) Information from that
survey on the ranges of distances to .
both the waste management boundary
and the property boundary from the
edge of land disposal units is presented
in the following Table 5; •
TABLE 5.—ESTIMATED DISTANCES TO PROPER-
TY BOUNDARY AND WASTE MANAGEMENT
BOUNDARY FROM UNO DISPOSAL UNITS
BASED ON PART B PERMIT APPLICATIONS
50 ft
166 ft
Estimated Distance to Downgradient Property Line from
Edge of Largest Land DUpooal Unit
*N = 177 [[[ 10% =
Mean- 1.365.. [[[ 25%=,
Median=500 ____ ___ ___ _ _________ ...... _ ..... 75% =
Range 0-19,000 f». ...... ----------- ........ _ .......... 80% = 470 ft
Estimated Distant* to Downgradient Property Une from
Edge of Srndlnt Land Disposal Unit
*N=38...; ....................................... „ ............ ___ '.. 10% t= 153 ft'
Mean=1,S04ft .............................. ______ 25%= 306ft
Median=6SB ft ------ ------------- 75% _ 1s06n
Range 71-9,500 ft .......... -------- .................... 90% - 4,202 ft
Estimated Dfetone* to Oowngndwnt W*de Management
Lira from Edga of Urgent Land Disposal Unit
•N*=91 -- __„ ____ _ ______ _ _____ , tn% = loft
Mean=4S6ft ..... . ................................. .. ..... __ 25% » 50ft
Median =167 ............................................... ...... 75% = 700 ft
Range 0-3,543 n ------------ 90%. 1,137 «
Estimated distance to Downgradient Waste Management
Line from Edge of Average Land Disposal Unit
*N=20 ............. „ ...................... _ ............. . ......... 10% = 23 ft
Mean=584 ft ...................... „ ................ _ .......... 25% = 63 ft
Median=250 ft ................................................. 7.5% = 986 ft
Range 20-3,228 ft ............................................ go% . 1,933 ft
Estimated Distance to Downgradient Waste Management
Une from Edge of Smallest Land Disposal Unit:
*N=39 ____ [[[ 10% = 10 ft
Mean=541 ft [[[ 25% =* 40ft
Median= 100 ft .................................... _ ........... 75% m 700 ft
Range=0-4,200 ft ........................................... 90% = 1,820ft
*"N" stands for the number of units evaluated.
Based on this information, the Agency
believes that selection of a distance of
500 feet is a reasonably, conservative
estimation of the point of potential
human exposure.
(A) Characteristics of the model. The
three dimensional transport equation
upon which the proposed ground water
model is based has terms representing
dispersion in three dimensions, and
chemical-specific decay and velocity. It
is presented as equation (1) written in
the form (Ref. 23):
-JL .!£.
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Federal Register / VoL 51, No, 9 / Tuesday. January 14, 1986 / Proposed Rules
in the x. y and z directions, respectively.
(m'/yr)
V=ground water seepage velocity assumed
to be in the x direction. (m'/yr)
Rf^retardaton factor, (dimensionless)
t =elapsed time, (yr)
=effective first order decay constant. (yr"'J
0 =volumetric water content of the porous
medium. (fimVcm11),
I =net recharge due to precipitation (yr~!).
The retardation factor. Rt. and the
effective decay constant, are defined as
follows:
(2)
and,
(3) X=.
Where:
Pk—bulk density of the porous medium
(8/cm'J
K<=distribution coefficient (cm'/g)
0= volumetric water content, (cm'/cm*)
Xi=decay constant for dissolved phase,
(yr")
Xa=decay constant for sorbed phase, (yr~l).
A schematic description of the three-
dimensional region considered is
presented in the following Figure 4;
The flow region is regarded as semi-
infinite in the x-direction (0
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Federal Register / Vol. 51. No- 9 / Tuesday, January 14, 198ff / Proposed Rules
1645
PERSPECTIVE FLOT '•'..-..
FtQUAE: 4 Schematic Description of Thr««-Dim«n«lon*l R*o
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Fedeiat Register / Vol. 51, No. g / Tuesday, January 14, 1986 / Proposed Rules
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^•••••••••^^••^•^•^•^^•••^^^••••i
alternative to identifying reasonable
worst-case values'for each model
parameter, EPA developed a procedure
that accommodates the possible
variation in environmental settings, the
uncertainties in specific chemical
properties, and the range of impact of
engineered system releases from land
•disposal units. The developed approach.
termed Monte Carlo simulation, involves
large numbers of computer runs (e.g.,
t.OOO to 5,000) with values for each input
parameter drawn from data sets
describing ranges of possible values and
. the distribution of values within the
range. Additionally, where parameters
are correlated, and therefore dependent.
the relationships are properly specified
in the Monte Carlo routine. The Monte
Carlo process proceeds as follows:
(1) Values from each input distribution
are selected at random.
(2) A value for the desired output
variable, G. (i.e.. back-calculated
concentration levels) is computed for
each randomly selected set of inputs.
(3) The input selection and
computation steps are repeated a large
number of times (e.g.. 1,000 to 5,000) to
. produce a well-defined distribution of
outputs.
(4) The output values are analyzed for
presentation as a distribution.
The ground water model parameters
' and input data requirements include the
following: ground water velocity.
porosity of the saturated media.
dispersivity of the aquifer, distance to
the measurement point, standard
deviation of the Gaussian source.
penetration depth of leadhate into the
aquifer, thickness of the aquifer, fraction
organic carbon content of the soil, pH
and temperature of the ground water,
and acid, base, and neutral hydrolysis
rates. To apply the Monte Carlo analysis
properly, relationships between these
environmental parameters must be
determined. The following Table 6
illustrates the expected dependence
among the ground water model
parameters and input data:
This table was constructed from a
combination of documented
observations and engineering judgment.
(See'the Background Document to the
ground water screening procedure (Ref.
2) for a discussion of the expected
dependent and independent
relationships among the input
parameters to the model.) In some cases
very weak dependencies may exist but
an assumption of independence is made
in light of the model's sensitivity to the
assumption. The data points denoted by
"D" are thought to be sufficiently
dependent to require correlated input
sequences. All pairs denoted by "I" are
considered independent. Independent
data sets can be developed as empirical
distributions of observed data, as
theoretical distributions from a "best-
fit" analysis-of observed data, or as
assumed distributions. Dependent data
sets can be developed as empirical.
joint, or multivariate distributions,
theoretical distributions, or from
functional dependencies among the
variables and parameters.
BILLING CODE 656O-50-M
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Federal-Register / Vol. 51, No. 9 / Tuesday, January 14,1986 / Proposed Rules
0 denotes dependence
I denotes weak or nc dependence
1647
" 'fab le 6— SUMMARY
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BILLING CODE 6MO-50-C
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1649
Federal Register / Vot 51, No. 9 / Tuesday, January 14. 1986 / Proposed Rules
The summary shown in Table 6
suggests that none of the variables or
parameters is totally independent of all
olher variables or parameters. In some
cases, however, an independent "seed"
distribution can be generated to which
other variables are correlated. For
example, the temperature (T) will
influence the hydrolysis rate constants
but the reverse is not true nor, for the
system studied, does anything else
influence temperature. Following this
rationale, the parameters and variables
are generated independently as follows.
(a) Thickness of the saturated zone. '
The thickness of the saturated zone, B.
influences the opportunity for vertical
dispersive mixing as the plume moves
downgradient. Literature values taken
from measurements and surveys were
used to derive a distribution for this
parameter. For the Monte Carlo analysis
the thickness of the saturated zone is
varied exponentiallyfrom 3 to 560
meters.
(b) Fractional organic carbon content.
The fractional organic carbon content.
foe, is used to determine the distribution
coefficient. KD. The distribution
coefficient can be determined from the
following relationship:
(5)
KD * (foe) (Koc)
where:
KOC-dislribution coefficient normalized ti>
organic carbon.
U is clear from this relationship that the
variation in foe leads directly to
variation in the KD and hence
retardation of the solute in ground
water. Unfortunately, few if any
comprehensive subsurface
characterizations of organic carbon
content exist. In general the values are
known to be very low, typically less
tHan .01. In the absence of evidence to
the contrary, the approach taken was to
assume a low range of Foe. A
distribution shape for this range was
determined by the distribution of
measured dissolved organic carbon
recorded as entries to EPA's STORET
data base (Ref. 110). The*assumption is
that dissolved organic carbon reflects
the existence (and hence distribution) of
organic carbon in the subsurface
environment being considered.
(c),Ground water pH. The model
assumes that the ground water is
sufficiently buffered to insure that the
pH is not influenced by input of.
contaminants or changes in temperature.
This permits a pH distribution to be
derived independently. STORET data
were analyzed, a distribution developed
and summary statistics generated for
pH.
(d) Ground water temperature,
•Assumptions about the independence of
ground water temperature are
essentially the same as for pH.
Temperature influences hydrolysis
reactions but the reverse is ignored-.
Temperature can also influence
sorption. but such effects are ignored in
this analysis because the influence of
temperature on sorption is much less
significant than its effect on hydrolysis
and the data required to determine this
relationship are not available.
(e) Leachatepenetration depth. The
depth. H, to which the leachate flow
penetrates the saturated zone is
probably related to the relative
differences in .the leachate velocity and
the ground water velocity. Because this
analysis is based on a closed landfill
and given the fact that disposal of free
liquids in landfills is now not permitted.
density gradients or stratification of
"floaters" or "sinkers" are not likely to
occur. Lacking any meaningful data, a
simple, independent, uniform
distribution ranging from a fixed
minimum of 2 meters to a fixed
maximum of 10 meters was assumed.
(f) Net recharge. Recharge, L is the
amount of water that enters an aquifer
system. It is a function of climate,
topographic, and soil properties. A
distribution for this parameter was
developed using the 18 national climatic
conditions previously identified in the
HELP model discussion for estimating
national distributions of leaching rates.
Since the ground water model
assumes that the porous media is
uniform, the effect of recharge causes
the ground water to rise and fall
uniformly. Thus, there is no change on
the gradient or ground water velocity.
The expression for estimating I is as
follows:
(6)
, = q'/H
where:
q'=net infiltration, m/yr
H = leachate penetration depth, m
A summary of the procedures used to
generate the independent input data sets
is given in the following Table 7:
TABLE 7.—SUMMARY OF PROCEDURES USED
TO GENERATE INDEPENDENT INPUT DATA SETS
input data
3
3H
Method of
generation
FD'
FD
FD
Source of data and/or
reference
Various literature
STORET. assumptions
STORET
TABLE 7.—SUMMARY OF PROCEDURES USED
TO GENERATE INDEPENDENT INPUT DATA
SETS—Continued
Input di
I u Method
I general!
Method of
generation
FD
i AO"
i Modeling
Source of data and/or
reference
STORET
Various literature
1 Fitted Distribution to empirical data.
' Assumed Distribution.
The fitted distribution (FD) method
refers to the development of a
mathematically defined frequency
distribution function by "fitting" various
possible distributions (e.g.. normal, log
normal, exponential) or mixtures of
distributions to the "observed" data and
selecting the "best fit" distribution for
use in the Monte Carlo process. In all
cases, EPA recognizes the possibility
that the data in STORET may represent
a biased sample. However, lacking
another alternative, EPA accepted the
data as representative of ground water
and subsurface conditions.
The remaining input parameters and
variables are dependent and cannot be
genera-ted without properly "matching"
each value with other related values.
The main purpose of building in
dependencies is to avoid unrealistic or
impossible sets of data. For example, a
uniform soil having high porosity
because of high clay content will rarely
if ever have high ground water velocities
because of the low hydraulic
conductivities. Failure to exclude such
possibilities, however, by assuming that
porosity and velocity are independent
will lead to unrealistic if not impossible
modeling results.
In general, precise functional
relationships among all the dependent
variables or parameters do not exist.
Similarly, observed data for all values
taken in sets do not exist or are
inadequate in number to permit a
statistical representation of the
dependencies. Fortunately, however,
equations do exist in the engineering
and scientific literature to permit
generation of sets of "possible"
combinations of input data. Generation
of consistent sets of input data is much
easier to accomplish than the more
rigorous but related task of predicting a
precise, site-specific set of values given
only one or two measurements at that
site. The parameters and variables to be
generated as dependent values are
discussed below.
(g) Dispersivity. The spreading of
solutes transported by ground water is
usually described as a combination of
molecular diffusion and mechanical
mixing. The relative magnitudes of each
are such that molecular diffusion can be
-------
»
Federal Register / VgE Si, Pfo9 /Taesday. January 14. 1986 / Propoaed Rnfeg
ignored. The property of the soil or
porous medium that is commonly used
to define the magnitude and direction of
dispersion is included in the dispersivity
parameters. A generalized theory to
describe dispersivity has not yet been
developed but recent work has noted a
strong dependence on scale (Refs. 16. 49,
79, 83, 84. and 94). Some investigators
(Ref. 84) have reported simple, linear
dependencies for longitudinal
dispersjvity, Y, as 10 percent of the
measurement distance, x.
(7)
\
0.1(x)
where;
X—mean travel distance.
More recently, Guven et. al. (Ref. 51}
completed a detailed theoretical
analysis and suggested an expression of
similar form
<7a)
L = 0.09-3 X
0.007
EPA believes that this relationship is a
reasonable approximation for
longitudinal dispersivity and •
appropriate for use in the Monte Carlo
routine.
Transverse dispersivity, =particte size density, g/cm3 and
pf= bulk density, g/cmj.
By assuming pp=2.65, equation 11 can
be rearranged to yield an expression for
estimating bulk density given the
porosity as follows:
(12)
2.65 (1 - O)
The particle density of soil materials
varies over a very narrow range and can
be fixed at a value of 2.65 gm/cm3. The
equation above can be used to derive a
frequency distribution for bulk density
given the previously generated
distribution for porosity.
(j) Velocity. The velocity of ground
water is a major determinant of the
transport of solutes in subsurface
systems. In uniform porous media, it is
the dominant factor and must be
properly specified in the Monte Carlo
process. Dependencies among the input
data (porosity and bulk density) must be
preserved while generating realistic
values of velocity.
Ground water flow velocities vary
widely. Mackay et al. (Ref. 73) report
that velocities typically range between 1
to 100 m/yr. These ranges apply to
typical "natural gradient" conditions
-------
1650
Federal Register / VoL 51. No. 9 / Tuesday. January 14. 1988 / Proposed Rules
arid higher velocities can exist under
both man-induced (e.g., well-field-
drawdown) and extreme natural
situations. For example, velocities in
excess of 9,000 m/yr have been reported
(Ref. 51) for a glacial outwash material.
Such data sources could be used to
develop an empirical frequency
distribution for velocity, but the
requirement to maintain dependencies
with soil properties is not easily met
using this approach.
Velocities are related to soil
properties and other site-specific factors
through Darcy's law. Using Darcy's law
and assumptions of steady flow in
uniform, saturated media yields the
following expression for average pore
velocity, V
(13) V
where:
K,=saturated hydraulic conductivity, cm/sec
S=hydraulic gradient
0=porosity
beause an expression for porosity, 0,
has already been developed, this
equation properly relates velocity and
porosity. The saturated hydraulic
conductivity, K,, reflects the "ease" with
which water is transported through
porous media and for any given fluid, K,
is a function of porous medium
properties such as particle size, grain
shape, connectivity, and tortuosity. To
the extent that K, is related to such
properties if functional relationships
exist for K,, then dependencies among
V, K, and 0 can also be represented.
Individual, site-specific measurements
for K, are usually difficult to make and
the spatial variability of "point"
measurements is the subject of much
current research. Also, site-specific
variations in K, values introduce
considerable uncertainty in modeling
ground water flow when point estimates
or averaged point values are used as
model inputs. The objective here is to
insure consistency in results while
representing the wide variations -
expected from site to site. Given this
objective (that is much less demanding
than an attempt to predict an accurate
K, for any given site), it is reasonable to
use an approximate functional
relationship. The most notable among
these is the Karmen-Cozeny equation
(R«f. 23}
(14)
where:
6 = porosity
d = mean particle diameter
Note that this equation relates saturated
hydraulic conductivity to porosity and
particle size diameter. Furthermore,
porosity, 6, is derived from the particle
density, pp, that is generated from a
"seed" distribution.
The remaining factor in the previous
equation for velocity is the gradient, S.
In general, the gradient is a function of
the local topography, ground water
recharge volumes and locations, and the
influence of withdrawals (e.g., well
fields). It is also likely to be indirectly
related to porous media properties.
Rarely are large gradients associated
with very high conductivities. No
functional relationships exists, however,
to express, this association. Thus,
another independent, "seed" distribution
is required. The potential problem with
the independence assumption is in
"extreme" values. Data sets having large
values for both K and S will also have
very large values for velocities, resulting
in unrealistic conditions. .These
conditions can be prevented by
bounding the velocities such that a fixed
maximum is not exceeded. The
observed value of 9,250 m/yr was
selected for this purpose.
The distribution for the gradient can
be assumed or derived from
observations. Gradient data were
included in the survey of Part B permit
applications and were analyzed to
develop a frequency distribution.
(k) Standard deviation of the
Gaussian distribution for the source
concentration. The standard deviation
of the Gaussian source, tr, defines the
nature of the leachate after it has mixed
with the underlying, saturated zone.
Because o-, reflects the nature and
extent of the leachate interaction with
the ground water beneath the facility, it
also reflects the failure of the engineered
controls on the facility (e.g., liners,
caps). From mass balance principles the
standard deviation,
-------
Federal Register / Voi 51, No. ft /- Tuesday. January 14, 198g / Reposed Rides
iaw
temperature, the need exists to adjust
these values to account for different
temperatures in the ground water. Using.
the generic activation energy
recommended by Wolfe (Ref. 126) of
, approximately 20 k calf mole, the
temperature correction factor can be
written as:
where:
l^a.n.b = second-order hydrolysis rate
constants for acid, neutral, or base
conditions at temperature T
Kr'*.n.i>'= second-order hydrolysis rate
constants for acid, neutral, or base
conditions at reference temperature, T,
T. Tr = temperature. "Kelvin
The temperature can also influence
the base-catalyzed hydrolysis rate
through influence on autoprotolysis of
water. Porous medium properties and
ground waters are sufficiently buffered.
however, to minimize this effect.
temperature corrections to pH are not
made.
(m) Distribution coefficient. The
relationships most suited for relating the
chemical distribution coefficient, 'Ko. to
soil or porous medium properties are
discussed in detail by Karickhoff (Ref.
65). In cases where reliable relationships
do not exist, measurements are required.
For many cases, hydrophobic binding
dominates the sorption process and it is
possible to relate the distribution
coefficient directly to soil organic
carbon. For these cases; the dependency
is given by:
(5)
= (Koc)
where . >
K,,. = normalized distribution coefficient
normalized to organic carbon
foe = fractional organic carbon
The values for fractional organic carbon,
foe. were generated as an independent •
parameter as previously described. The
equation above is used to preserve
dependency between porous media
properties and chemical sorptive
properties. For other binding
mechanisms described by Karicknoff
(Ref. 65), including those for polar,
ionizable compounds, adjustments will
be made on a case-by-case basis'as
appropriate.
(n) Data generation results. The
combination of data sources and
approaches described above were used
to generate input frequency distributions
for each of the parameters and forcing
function variables (see Ref. 2). In some
cases intermediate or precursor
variables were also generated to enable
representation of appropriate
dependencies among the variables and
parameters. The following Table 8 gives
a summary of the distributon types and
parameters for each model parameter or
variable. For derived distributions, only
the mean and range-of the synthesized
data are given. In some cases only
single, fixed values were selected
largely based upon their nature (e g., a
chemical specific rate constant).
BILLMO CODE 65M-5O4I
-------
Federal Register / Vol. 51. No. 9 / Tuesday. January 14.1986 / Proposed Rules
Table 8— SUMMARY OF RESULTS FOR INPUT DATA ' GRNERAT ION
Parameter or
Variable
Temperatuie, °C
ph
Dissolved
Organic-C mg/1
Distribution
Tvoe
Mormal
Mormal
Lognormal
Distribution-
Parameters
mean std d&
14.4 5.29
6.2 1.28
|1.99 1.09
Range
Y.I. min-max
(0.0 - 30.0)
(0.3 - 14.0)
(0.01 - 6.39)
coc
d, cm
Pft, gm cm"
KS , cm sei
S
V, myr"
B» m
.-1
H, m
•I, m
Ei myr
X,' m
ka ^-
<(, ,./r,—l
Kn yr
k^ MM
1" yr."1
Lognormal -5.76
Log^Qun iform .00063
derived from d
derived from 9
derived from Q, d
exponential .0309
derived from s, KS, 8
exponential. 78.6
mixed; exponential
un i f o rm
derived from uniform .6.0-
•node ling • .- • •
• -noMe 1 i ng .' ;
derived from q, Aw, V,
. : • single values
•.,.:.,' . .single values ,
*• ' • •
'• '.' " unifocnt
.;••"'. sinijle values
i ,.ch,emical specific value
• clvemical -specific value
.. .chemical, specific value •
, . .che-nic.U specific value
3. 17 ( .001 - .01)
( .0004 - 0.10)
( .30 - .56)
(1.16 - 1.8)
( .0001 - .48)
( .00001- 0.10J
( .01 - 9250)
(3.0 - 560)
(23 - 930,000)
— (2.0 - 10.. 0)
,,'... <.°-P - .3)' ;
: :...•:•... (0.0025 -',0.91 ).
( .001 - -60,000)
(O.lx )
(0.0333x
<0.0025x
(152.4m)
- O.Olx)
BHUNte CODE (560-SO-C
-------
Federal Register / Vol. 51, No. 9 / Tuesday, January 14, 1986 / Proposed Rules
The ground water model was
implemented with the input data
generated by the data, assumptions, or
modeling reported in the previous units.
Two general cases can be described:
Modeling results for non-degrading
constituents, and for degrading
constituents. The behavior of all non-
degrading organic chemicals will be
identical because sorption, as
implemented in the model, does not
influence dissolved concentrations.
Thus, a single cumulative frequency
distribution in the form of a graphical
presentation or tabulated values can be
produced for all such compounds. For
constituents which degrade, a unique
cumulative frequency distribution will
be produced for each individual
constituent. To illustrate the results of
the Monte Carlo simulations, tabulated
values for. the frequency distribution for
non-degrading chemicals are shown in
the following Table 9:
TABLE 9—MODEL SIMULATION RESULTS FOR
NON-DEGRADING CHEMICALS AND CHEMI-
CALS WITH A ONE YEAR HALF-LIFE .
Cumulative Percentilet
9.25
0.50
075.
0.90
0.95
CD'1 value non-
degrading case
1 «'10~
1 8x10"
45x10
4 4 x 10"
77'<10"
1 year half-lite
4 3x10"
• • 00=0^/0,
wtiefe:
C^0(=Screening level.
CL .-- teachate concentration
The cumulative frequency distribution
provides estimates of the likelihood or
probability that the target concentration
level (e.g., reference dose) would not be
exceeded if the extract levels are
achieved, given the range and
distribution of values that may be
expected for each of the various
environmental parameters known to
affect such concentrations. Using this
approach, EPA can be assured that the
level of treatment selected will ensure--
that downgradient concentrations will
not exceed the specified target
concentration at any desired confidence
level.
The Monte Carlo approach, thus,
allows the Agency to evaluate the
uncertainty in the characterization of
the input data to the model. The Agency
believes that the Monte Carlo approach
provides a sound basis for evaluating
land disposal of hazardous wastes and
establishing the concentration levels for
all hazardous constituents.
(o) Peer review. The proposed ground
water screening procedure was
presented to the Environmental
Engineering Committee of EPA's Science
Advisory Board for its review. The SAB
concluded that, the procedure was
technically and mathematically valid
given the underlying assumptions (Ref.
2). EPA responded to specific
recommendations by the SAB on the
following subjects: Accounting for
dilution of leachate entering the aquifer;
speciation of metals in ground water;
and considering the variability and
uncertainty in properly specifying a
generic environment. The Agency
believes that today's proposal properly
addresses the major concerns of the
. SAB.
The Agency recognizes that some of
the assumptions and components of the
ground water screening procedure, as
described above, may need to be re-
examined and adjusted if necessary.
Specifically, the Agency believes that
the analysis of chemical flux rates from
Subtitle C land disposal units using the
HELP model may need to be further
evaluated. The HELP model was
designed to facilitate estimation of flux
rates from landfills. EPA specifically
requests comment on the
appropriateness of using the HELP
model to develop estimates of long-term
flux rates from land disposal units. The
Agency seeks comment on whether flux -
rates should be estimated for operating
landfills, surface impoundments, and
waste piles as well as information on
alternative models or methods which
may be appropriate for estimating flux
rates.
The Agency believes that its
assumption that the leachate
penetration depth, H, varies uniformly
from 2 to 10 meters, may need to be re-
examined and adjusted if necessary.
Limited data are available describing
the depth to which leachate may
penetrate into an aquifer at all types of
land disposal facilities. Rather than
assume a single value for H, the Agency
decided to vary it uniformly over a small
range to account for possible differences
in disposal unit sizes and potential
leachate volumes entering the aquifer.
The Agency requests comment on the
appropriateness of this assumption and
•requests further information to
characterize better the depth to which
leachate may penetrate into the
saturated zone.
The Agency believes that this ground
water screening procedure will identify
hazardous constituent concentration
levels that insure .that land disposal of
such constituents protects human health
and the environment from harm due to
exposure to ground water. The
procedure accounts for variability in
both land disposal settings and in •
chemical properties. The Agency
specifically requests comments on all of
the parameters and variables
considered in the ground water fate and
transport model and the
characterization of the data describing
the parameters and variables used in the
Monte Carlo process. If a commenter
believes that any of the data is
incorrectly characterized, the Agency
would.like comments on how it can be
better characterized.
The ground water modeling
procedure, as all modeling procedures,
has limitations. This procedure assumes
the waste leachate is mixed with fresh
water. This neglects the effect of prior
contamination of the aquifer. The
procedure also does not consider the
possibility that constituents which
hydrolyze can form more toxic
components. These components
potentially may be more toxic than the
parent constituent. Moreover, as noted
in the discussions, the model of
necessity incorporates a number of
assumptions, such as uniform, •
homogeneous, and isotropic porous
media, that do not represent real world
conditions. Although these factors are of
importance, the Agency is unable to
take them into account in this generic
screening procedure.
The Agency believes that this
procedure, with its limitations, is
reasonable. EPA requests comment,
however, on the use of the models
incorporated in the ground water
screening procedure and how to deal
with these limitations.
(p) Metal speciation component.
Although EPA is not specifically
proposing an approach for evaluating
metal fate and transport in ground water
in today's proposed rule, the following
outlines the Agency's current thinking
on how 'the application of the ground
water equation will be developed for
metals.
- Because the conditions and processes
by which metals exist and react in the
environment are not considered in the
ground water fate and transport
equations it is not appropriate to apply
the equations to metals without further
analysis. The ground water fate and
transport equation limits degradation to
hydrolysis. This is a reasonable
assumption for organic constituents, but
is inadequate to describe metals since
they cannot be "degraded" by this
mechanism. Yet metals and other
chemical elements, usually combined in
the form of ores and minerals, are a
natural part of the environment. In fact/
many metals are too reactive to remain
in the metallic state, and tend to form
.-such combinations. The particular
compound formed is determined by
conditions such as the availability of the
particular anion species, the pH of the
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1654
Federal Register / Vol.
51, No. 9 / Tuesday. January 14, 1986 / Proposed Rules
environment land the oxidation state of
the metal. Usually, metals undergo a
variety of complex reactions resulting in
the formation of multiple compounds.
Each metal will exist in the
subsurface environment as a relatively
complex distribution of different
species, each having a specific set of
properties. Relative concentrations of
individual species within the
distribution are controlled by
equilibrium constants governing the
individual reactions, and by the
chemical environment in which this
speciation process occurs. Some metals
exist in several oxidation states
simultaneously and form a number of
individual species of widely differing
chemical characteristics. Because such
chemical and physical characteristics
determine the ability of the species to be
transported, it is virtually impossible to
estimate the overall transport potential
of a given metal without consideration
of these processes.
To account for multiple species
distribution, and immobile solids
formation, a speciation model
component will be added to the ground
water back calculation model. In the
initial calculations the metal is treated
as a non-hydrolyzing (non-degrading),
npn-sorbing entity. The contribution of
dispersion is accounted for by means of
the ground water fate and transport
equation, and the metal is speciated
using an equilibrium-speciation model.
Initially, the 10 metals included in the
California List will be evaluated. These
include arsenic, barium, cadmium,
chromium, lead, mercury, nickel,
selenium, silver, and thallium. The basic
assumptions of the speciation model
component for analyzing the transport of
metals in ground water are:
(i) Metals exist in ground water
environments as distributions of
multiple, dissolved-phase species and
precipitated solids.
(ii) All dissolved species are freely
mobile and available for transport as
implemented by the ground water back
calculation model.
(iii) Metals (excluding radionuclides)
are conservative (non-degrading)
entities.
(iv) Overall metal speciation
distributions are sensitive to properties
of the subsurface environment, including
pH, redox potential (Eh) and dissolved
solutes.
(v) pH and Eh) of the aquifer are
effectively buffered against changes
caused by introduction of the leachate.
(vi) Transport of individual metal
species is governed by the specific
properties of that species (mobile versus
immobile); however, individual species
are related to each other through the
equilibrium constants.
Estimates of metals species
distributions are determined using the
geochemical model MINTEQ (Refs. 113
and 114). MINTEQ is an equilibrium
model that uses the equilibrium constant
approach to solving the chemical
equilibrium problem. The mathematical
structure of MINTEQ is derived from
MINEQL (Ref. 123) and the data base
and sorption algorithms are from
WATEQ3 (Ref. 19).
Consistent with the overall approach
to the back calculation model, generic
ground water chemical specifications
will be developed to reflect a national
median ground water chemical
environment. This will be accomplished
by extracting data tabulated for well
waters in the EPA STORET (Ref. 110)
data base. Backgroud analytical
concentrations of the 10 metals will be
determined from this data base along
with concentrations of several key
anions cations, organic carbon contents,
Eh. and pH. Analysis of the data base
indicates that wide variations in ground
water chemical specifications exist.
Mean values are strongly influenced by
a few extreme values. For this reason
median will be used in establishing
generic ground water specifications. The
final specifications will consist of the
median values for all variables except
Eh, pH, and organic carbon content.
For the variables of Eh and pH, EPA
believes that a single set of generic
specifications cannot be selected which
accurately reflects the range of
conditions existing at all sites. For this
reason, jan "uncertainty window"
encompassing a range of Eh and pH
values, will be defined. Speciation
equilibria calculations are performed
repeatedly using several Eh and pH
combinations in conjunction with the
median values of other variables such as
anion concentration. Totaljiissolved
metal concentrations are calculated for
each combination.-The universal
influence of Eh and pH on the overall
speciation equilibria is reflected hi the
range of metal concentrations obtained.
This approach to the uncertainty
problem, generated by using generically
derived input sets, differs from the
Monte Carlo sensitivity analysis used in
other parts of the procedure, in that Eh
and ph are the only variables tested.
Variation of other input variables is not
feasible given the statutory deadlines
and the computationally intensive
nature of MINTEQ (Ref. 114) along with
the almost infinite range of possible
background chemistries.
An attempt will be made to evaluate
sensitivities of the 10 metals for reacting
with each other. Precipitation and
formation of solid phases may result if
the cation of one metal compound reacts
with the anionic species of another
metal compound, thus reducing the "
dissolved (mobile) concentration of
each. Taken separately, either metal
might remain in solution at a somewhat
higher concentration. To evaluate some
of these possibilities, the 10 metals
under investigation will be introduced
into the speciation model at different
analytical concentrations ranging up to •
1,000 times the health-based starting
limit 8
Sorption is not considered a
speciation process for the purpose of
this analysis. This constraint is made to
be consistent with the assumptions
applied to organic constituents in the
ground water fate and transport
equation. For organics, sorption
influences only the time of transport.
Thus for constituents that do not
"degrade," sorption will not affect the
concentration levels predicted by the
ground water model.
Because of the very complex nature of
the metal speciation mixtures
investigated, formation of a large
number of solids is possible. To avoid
complicating the speciation calculations
past the point of manageability, only
those solids which contain 1 or more of
the 10 test metals as a component will
be specified. Final selection of solids is
a critical issue and is discussed further
in the following paragraph.
Many organic compounds form
complexes with metal ions causing some
metal solubilization. To estimate the
impact of these organic ligands on the
overall speciation equilibria requires
information on the amount and nature of
specific organic compounds present hi
various types of leachates as well as.
thermodynamic data on the metal-
organic complexes. In the absence of
these data, a simple model system of six
common organics will be used to mimic
performance of real systems. This
approach was used by Morel et al. (Ref.
80) hi modeling speciation reactions in
sewage effluents. The model compounds
represent several key functional groups
and a broad span of abilities to complex
metals. Acetate, tartrate, glycine,
salicylate, glutamate and phthalate were
selected as the organic compounds for
analysis because thermodynamic data
have been measured for these ligands.
Concentrations of each are set by
apportioning the median ground water
organic carbon concentration
determined from STORET data equally
(molar basis) among the six compounds.
The procedures mentioned above for
modeling metal speciation are based
entirely on an equilibrium model and it
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Federal Register / VeL^Sl,
A Tuesday, January 14. 1988 / Proposed Rules
is difficult t& estimate how nearly
ground water systems approach
equilibrium conditions. Lindberg and
Runnels (Ref. 89} investigated a number
of redox couples, in ground waters and
concluded that none of the 30
representative waters investigated
reflected internal redox equilibrium.
Potential errors due to nonequilibrium
are partially accounted for in the EN, pH
uncertainty treatment noted earlier. It
should, however, not be assumed that
all potential errors have been
eliminated.
One of the greatest potential impacts
of using an equilibrium model is
reflected in the prediction of solid
phases. MINTEQ {Ref. 114] allows the
. user to select the solid phases. By
judiciously eliminating solids which are
known to be kinetically limited, a major
weakness of using the equilibrium model
can be removed. These are judgment
calls which will be accomplished
through review by a panel of experts.
All speciation models rely on a wide
range of data from many sources. The
MINTEQ data base (Ref. 114) has been
carefully assembled over time and can
be considered state-of-the-art. It is,
however, still subject to further
validation.
3. Surface Water Back Calculation
Procedure • .
a. Introduction and objective. In
establishing back-calculated screening
levels, the.Agency has.evaluated the
potential for human and environmental
exposure to hazardous constituents
resulting from migration from land .
disposal units via surface water '
pathways. Surface water contamination
may result in exposure of humans and
aquatic life to hazardous constituents as
shown in the following Figure 5:
BILLING CODE 6560-50-*!
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1656
Federal Register / Vol. si. No. 9 / Tuesday. January 14,1986 / Proposed Rules
R
U
N
O
F
F
L
E
A
C
H
I
N
Q
SURFACE WATER
GROUND WATER SEEPAGE
GROUND WATER
HUMANS
AQUATIC LIFE
CONSUMPTION
OF FISH
DRINKINO
WATER
FIGURE 5 —ROUTE OF EXPOSURE FROM LAND DISPOSAL
. THROUGH THE SURFACE WATER MEDIA
BILLHW CODE 6MO-SO-C
-------
Pedfttafr Ragbter / Vpt 51, No. 9. / Tuesday. January 14. 1986 / Proposed Ru)es 3657
The Agency considered three
scenarios, 'or routes of exposure via
surface water, defined as streams in this
proposal. The scenarios considered
include: (i) Human exposure via
drinking water, (ii) human exposure via
fish consumption, and (iii) direct
exposure of aquatic organisms.
The potential for exposure of humans
and aquatic life to contaminants due to
runoff from a storm event is not
reflected in this analysis. Existing
regulations require that all landfills.
land treatment systems, waste piles, and
surface impoundments be designed such
that, at a minimum, runoff from a 25-
year, 24-hour storm event is contained
{40 CFR Parts 284 and 265). The Agency
believes that these performance
standards provide an acceptable level of
containment, and thus has not
calculated constituent screening levels
based on surface water exposure from
such events.
The proposed surface water screening
procedure involves a back calculation,
using a fate and transport model, from
concentrations that will not adversely
affect human health and the
environment at points of potential
exposure to the constituent
concentration in leachate emanating
from a land disposal unit. As illustrated
in the following Figure 6, this analysis
encompasses contamination of streams
through interception with ground water
contaminated by releases of hazardous
constituents in leachate from land .
disposal units:
FIGURE 6 —SCHEMATIC DESCRIPTION OF SURFACE
CONTAMINATION PATHWAYS
The Agency has characterized specific
surface water pathways leading to
human and environmental exposure and
evaluated the likelihood of exposure
from each pathway. Where the back-
calculated surface water concentration
level for a constituent is more stringent
than the screening level developed
through the ground water model, the
surface water screening level replaces
the ground water screening level for
purposes of establishing the section
3004(mj treatment standards for that
constituent according to the proposed
decisionmaking framework presented in
Unit II.
When the ground water and surface
water screening levels for the relevant
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1658
•Federal Register / Vol. 51. No. 9 / Tuesday. January 14. 1986 / Proposed Rules
constituents In the solvent- and dioxin-
containing wastes addressed in today's
proposed rule were compared, only the
surface water screening level for
pentachlorophenol was more stringent
man the ground water screening level.
Thus, the screening level for
pentachlorophenol is based on the
surface water model.
b. Pathways leading to contamination
of surface water and exposure to
humans and the environment.
Scenario 1: Exposure of humans
through drinking water to surface water
contaminated by leachate carried
through the ground water. Exposure of
humans to surface water through
drinking water contaminated by
leachate transported in ground water
consists of six stages, commencing with
failure of the waste containment unit,
continuing with transport of the
contaminant in ground water, mixing of
the contaminant with uncontaminated
stream water at the point of entry to the
stream, downstream transport of the
contaminant in the stream, treatment of
the contaminant in a drinking water
plant, and concluding with exposure of
the contaminant to humans via drinking
water (Ref. 13), This scenario is
described schematically by the flow
chart in the following Figure 7(a):
WASTE
CONTAMEft
V FAILURE J
STREAM PLOW
TRANSPORT
M GROUND WATER
MIXING AT
ENTRY POINT
TRANSPORT
IN STREAM
(STEADY SOURCE)
DRINKING WATER
PLANT
[HUMAN EXPOSURE VIA DRINKING ^
WATER CONSUMPTION
FIGURE 7 (a)—FLOW CHART FOR SCENARIO 1
Through these stages, the
concentration is successively reduced
from the leachate concentration to the
concentration at the drinking water
source. The attenuation factors that are
derived in Units III.A.3.e and f account
for the effects of contaminant transport
in ground water, initial mixing at the
area of leachate entry into the stream,
contaminant transport in the stream,
and treatment in the drinking water
olant.
Scenario 2: Exposure of humans
through fish consumption to surface
water contaminated by leachate carried
through the ground water. Humans may
also be exposed to hazardous
constituents in leachate carried through
the ground water to surface water
through the consumption of fish residing
in the contaminated surface water:
Scenario 2 consists of five stages
commencing again with waste
containment .unit failure, continuing with
transport of the contaminant in ground
water, mixing of the contaminant with
uncontaminated stream water at the
area of entry to the stream, uptake of the
contaminant by fish, and concluding
with exposure of the contaminant to
humans via consumption of fish (Ref.
13). This scenario is depicted in the
following Figure 7(b):
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Federal Boater / VbL M, No, » / Tuesday, January i* igae / Proposed Roles
STREAM PLOW
TRANSPORT
IN QROUNO WATCH
MtXINO AT
ENTRY POINT
UPTAKE BY FISH
[EXPOSURE TO HUMANS)
FIGURE 7 (b)—FLOW CHART FOR SCENARIO 2
Through these stages, the input
Concentration is reduced from the
ieachate concentration to the
concentration in the stream and then
increased to the bioconcentrated level in
the fish. Attenuation factors account for
the effects of contaminant transport in
the ground water, initial mixing at the
area of Ieachate entry into the stream.
and biochemical exchange processes
between fish and the contaminated
surface water ("reverse" attenuation).
The derivation of these attenuation
factors can be foond in Unit ULA.3.6.
Scenario 3: Direct exposure of aquatic
life to surface: water contaminated by
Ieachate earned througfi ground water.
Aquatic life may be exposed1
continuously to hazardous constituents
in Ieachate carried through the ground
water to surface water. Scenario 3
consists of four stages commencing
again with waste containment unit
failure, confirming with transport of the
contaminant in ground water, mixing of
the contaminant with uncontaminaf ed
stream water at the area of entry to the
stream, and concluding with exposure of
the contaminant to aquatic organisms
residing in or near the initial mixing
zone (Ref. 13). This scenario is depicted
in the following Figure 7(c)t
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1660
Federal Register / Voh 51. No. 9 / Tuesday. January 14. 198(T / Proposed Rules
STREAM FLOW
WA8T1\
ONTAIN6M— f
FAILURE/
J
TRANSPORT
IN GROUND WATER
exposure TO \
MIXINQAT
ENTRY WDINT
*
.AQUATIC ORGAN*
FIGURE 7(c) — FLOW CHART FOR SCENARIO 3
Through these stages, input
concentration is reduced from the
leachate concentration to the
concentration in the stream. Attenuation
factors account for the effects of
contaminant transport in the ground
water and initial mixing at the area of
leachate entry into the stream. The
derivation of these attenuation factors
can be found in Unit UI.A.3.e.
c. Description of scenario stages. In
this analysis, the Agency assumes that
the land disposal unit is located in an
upland watershed and is hydraulically
connected to a stream as, shown in the
following Figure 8:
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Fedet«l:Ragistet / Volt 51« Nov. ft-A Tuesday, January 14.- 1§88 / Proposed Rides
1001
LAND
DISPOSAL UNIT
GROUND WATER
FLOW
CONTAMINANT PLUME
FIGURE 8 —CONTAMINANT TRACKING AND TRANSPORT IN
GROUND WATER SYSTEM
Ail three surface water scenarios
addressed in today's proposal
commence with failure of liners and
leachate collectors at the land disposal
unit, resulting in release of hazardous
constituents in leachate to the aquifer
directly below the land disposal unit.
The transport of hazardous constituents
through the ground water pathway is
described by a one-dimensional ground
water equation-fRef. 13). The Agency is
conducting further analysis to determine
the effect of including dispersion on the
surface water screening levels. The ...
average contaminant concentration at
the area of leachate entry into the
stream is related to the leachate
concentration directly-belew. the land
disposal unit by aground water
attenuation factor. This attenuation
factor is a function of the fraction of the. •
chemical not transformed by hydrolysis
or removed by speciation>(over a
distance of 500 feet); the initial leachate
plume flow, and the contaminated plume
flow, .at the edge of.the stream,
In today's proposal, contaminated -; •
ground water is assumed to travel a
distance of 500 feet from the
downgradient edge of the disposal unit
before it intercepts the^nearest surface
water body. The distance of 500 feet
was selected to be consistent with the
distance employed in the ground water
component: However, the. Agency is
further evaluating the appropriateness
of the use of this distance in the surface
wates component and may revise it
{upward or downward) if it is
determined that it does not accurately
reflect a conservative point of
interception of ground water with
surface water. The Agency requests
comments on the appropriateness of 500
feet and data supporting this or other
distances. - • ' • • . • '
The contaminants are then discharged
into the surface water through ground
water seepage along the side and the
bottom of the stream where the ground
water system and the stream intercepts.
As the contaminated ground water
plume enters the surface water, it mixes
with uncontaminated water supplied by
the oncoming streamflow as shown in
the following Figure 9:
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1662
Federal Register / Vol. 51. Na 9 / Tuesday. January 14. 1986 / Proposed Rules
LAND DISPOSAL UNIT
STREAM FLOW
: GROUND
$ WATER -
/?>."• FLOW
FIGURE 9 —GROUND WATER LOADING OF CONTAMINANT
INTO THE STREAM
The potential hydraulic-impacts on the
ground water flow field by the adjacent
surface water are assumed not to
impede the discharge of contaminated
ground water to the surface water.
Consistent with the ground water
component, the surface water model
assumes continuous ground water
loading. As the ground water enters the
stream through the subsurface sediment,
areas of contaminant concentration
greater than that of the average
concentration in the water column will
develop. For example, the concentration
of the contaminant in the stream bed
during discharge will be greater than the
contaminant concentration in the water
column where mixing with the
uncontaminated water has occurred.
The Agency requests comment on
methods to account for these "hot spots"
and their effects on bottom-dwelling
organisms.
An initial mixing zone in the stream is
developed over the contaminant
discharge area. The Agency assumes
that within the mixing zone the depth of
the stream is small, since it is assumed
to be located in an upland watershed.
Therefore, vertical mixing is complete
(Ref. 13). However, lateral mixing may
be incomplete. Based on mass balance
considerations, the laterally averaged
concentration reaches a maximum near
the leading (downstream) edge of the
mixing zone. The contaminant mass
being loaded into the stream is the
product of the volumetric ground water
discharge rate and the average
contaminant concentration in the ground
water as discussed in IJnit IH.A.3.e. The
average contaminant concentration at
the downstream edge of the mixing zone
is related to the average contaminant
concentration in the ground water by a
stream flow dilution factor. This dilution
factor is the contaminated ground water
plume flow at the area of interception
with the stream divided by the total
stream flow at the downstream edge of
the mixing zone.
Since fish are mobile over the length
and width of contaminated stream, the
Agency assumes that an individual fish
will be exposed to a wide range of
contaminant concentrations during its
lifetime. Therefore, the average
contaminant concentration in-the
surface water in which the fish resides
is related to the ground water
contaminant concentration by the
stream dilution factor previously
discussed, which accounts for the width
and depth of the portion of the
contaminated stream where significant
-------
RtigiatoR / .Vol. SI. Np.,9 / .
- January 14. 198& /« Proposed Rules
1663
chemical degradation hasnotyet .«< . -
occurred* Essentially, tEe. Agency ia
proposing not to base devaluation of
surface water impacts onLthamaximum
concentration of hazardous constituents
in the stream, but instead to average the
maximum concentration that would be
found along the bank of the stream with
the lower concentrations that would be
found in other less contaminated or non-
contaminated areas of the stream. Public
comment on this issue is specifically
requested. : . .
If contaminant concentrations are
sufficient, aquatic organisms may suffer
chronic toxic effects. Water Quality
Criteria have been established by EPA'
to protect against these effects. The
derivation of these Water Control
Criteria is discussed in Unit III.A.l.g.
These criteria specify acceptable
concentrations, durations of averaging
periods, and frequency of allowed
excursions. To prevent a potential
hazard to aquatic life, in this analysis
the average contaminant concentration
in the surface water is directly equated
to the Criterion Continuous
Concentration Water Quality Criteria.
For each constituent subject to today's
rulemaking, a back-calculated surface
water concentration level was
developed using the entire WQC as the
starting point Comparing the ground
water and surface water screening
levels for the chemicals included in
today's proposed rulemaking indicates
that pentachlorophenol is the only case
where the back-calculated surface water
concentration level should be based
upon concern for aquatic species. The
Agency notes, however, that this
conclusion is based upon the
assumption that 500 feet is an
appropriate generic estimate of the
distance from RCRA land disposal units
to the nearest surface water bodies. If a
distance shorter than 500 feet is used in
the calculation, additional constituents
covered by today's proposal may be •
affected.
Chronic toxic effects in humans may
be caused by the consumption of
contaminated fish and are addressed in
.Scenario 2. The dissolved contaminants
are taken up by the fish residing in or
near the initial mixing zone through
exchange across the gill and gut
membranes and through the skin and
stored in the fatty tissues. The ability of
aquatic organisms to bioconcentrate
contaminants is a function of their lipid
content. Lipid content of fish varies with
species, age, and time of year. In this
analysis, -a range of lipid content values
accounts for the variation among
species. By assuming steady-state
discharge of contaminated ground
water, the. analysis results in'a: . .._,
contaminant concentration in the body
of the fish that is in equilibrium with the
contaminant concentration in the
surface water. When these exchanging
processes have reached equilibrium, the
average contaminant concentration in
the whole body of the fish is related to
the contaminant concentration in the
stream by the product of the dissolved
aqueous contaminant concentration and
a contaminant-specific bioconcentration
factor, which depends upon the nature
of the contaminant and the species of
the fish. To prevent a potential hazard to
human health, the average concentration
in the whole body of the fish is equated
to an apportioned human reference dose
that is calculated using a consumption
rate of 6.5 grams of fish per day (45 FR
79353, November 28,1980). For certain
compounds (those with high K,,w
coefficients), use of apportioned human
references doses in fish as the starting
point of the surface water back
calculations would result in maximum
acceptable contaminant concentrations
in surface water that are lower than
maximum acceptable contaminant
levels in drinking water or the human
drinking water reference dose, due to
their high bioaccumulation potential.
Accordingly, the Agency has not
accounted for bioaccumulation in fish in
the surface water back calculation
levels but father is proposing to cap off
the stringency of the surface water back
calculations such that contaminant
concentrations in ground water entering
streams are never required to be lower
than human drinking water
concentration limits. The Agency
specifically requests comment on this
proposal.
Following initial dilution in the
stream, the contaminant is routed a
specified distance downstream from the
edge of the initial mixing zone to the
intake of a drinking water treatment
plant. The contaminant concentration at
a specified downstream intake point is
related to the contaminant
concentration in the initial mixing zone
by an attentuation factor (derived in
Units III.A.3.6 and f) that accounts for
the combined influences of advection,
longitudinal and lateral dispersion.
degradation and sorption occurring
during downstream transport over the
specified distance.
Humans are exposed to the dissolved
chemicals through the consumption of
drinking water obtained from the
treatment plant whose intake is
assumed to be located in the zone of
contamination downstream from the
initial mixing zone. The Agency invites
comment on the method for determining
the appropriate distauce-from the initial
mixing zone to a downstream drinking-
water plant As a result of this treatment
occurring in the drinking water
treatment plant, the contaminant
concentration is further reduced by a .
final attenuation factor accounting for
the reduction in contaminant - .
concentration achieved through a
treatment process in which solids and
sorbed chemicals are removed (derived*
in Unit UI.A.S.e).
To ensure that there is no health
hazard due to human ingestion of
contaminated surface water, the
concentration in the treated drinking
water is equated to the specified human •
drinking water reference dose, and the
surface water back calculation
commences to derive the maximum
acceptable leachate concentration.
However, as long as the same distance
is used in the ground water and surface
back calculation, the surface water back
calculation need not be conducted. EPA
is confident that its proposed ground
water component will ensure that •
contaminant concentration levels in
ground water plumes entering surface
water will be no greater than the
drinking water portion of the human
reference dose. Further reductions in the
contaminant concentration result from
initial mixing with the stream, dilution
and chemical transformation during
downstream transport, and drinking
water treatment. Given the above
assumptions, releases of leachate from
RCRA land disposal units can be
presumed not to cause harm to human
health through treated surface water
ingestion as long as they are confined to
the leachate thresholds derived through
the ground water component. However.
if a distance of less than 500 feet is
employed as a more appropriate
conservative generic estimate of the
distance from disposal units to nearest
surface water bodies, the key
assumption that contaminated.ground
water entering surface water bodies will
do so at concentrations no greater than
the fractionated human drinking water
reference dose will no longer be valid.
and the surface water back calculation
would have to be conducted.
d. Implementation. The steady-state
analytical solution has been
programmed into a Fortran computer
code, D4WATER. This code has been
used to establish the back-calculated
surface water concentration levels for
hazardous constituents subject to
today's proposed rulemaking.
As in the ground water component,
the Agency has utilized a Monte Carlo
uncertainty analysis to allow for the
possible variations in environmental
-------
Federal Register / Vol. a. ffa 9 / Tuesday. January 14. lfla£ / Erapawsi Sole*
settings and the uncertaintfesln the
specific chemical properties (see Unit
III.A.2.d, General dimensional
relationships). Further detail on the
Monte Carlo analysis is provided in
Background Document for the Surface
Water Screening Procedure (Ref. 5.).
e. Equations describing transport and
dilution processes. In this unit.
equations for determining the dilution
factors corresponding to various
contaminant pathways are presented
(Ref. 13). Where appropriate, the key
equations are derived. Major symbols
usedare fisted under Notations in Unit
in.A.J.g.
i. Ground water loading and initial
dilution, For the ground water pathway,
the edge-of-stream concentration is back
calculated to the leachate concentration
via the ground water equation, which
considers, among other things, lateral
dispersion and chemical hydrolysis.
The ground water dilution factor in
Equation (Al) can be calculated using
mass balance. The average
concentration at the ground water outlet
or surface water entry area, Cr and the
leachate concentration. Q, may be
related by:
(Al)
where £«. is the ground water
attenuation factor. Consider the
situation illustrated in the following
Figures 10 (a) and (b):
BftUMO COOe 65MHMHW
-------
LAND DISPOSAL
GAUSSIAN DISTRIBUTION
/^
A8
AQUIFER BASE
FIGURE 10(a)
STREAM BED
FIGURE 10(b)
FIGURE 10—SCHEMATIC DECRIPTION OF GROUD WATER
CONTAMINANT LOADING AND AND DILUTION DUE TO MIXING
OF CONTAMINATED GROUND WATER WITH FRESHWATER
FROM STEAM FLOW
BILLING CODE 656O-50-C
-------
166ft
Federal Register / Vol 51. No.-9.-/ Tuesday. January 14. 1986 / Proposed Rules
It is assumed that the transport in
ground water has reached a steady-state
condition. The contaminant mass flux
leaching from the land disposal unit in-
to the ground water system, mL, is given
by:
(A2) mL=QLCL
where QL is the volumetric rate of
percolation through the land disposal
unit and CL is the leachate
concentration. The contaminant plume
intercepts the stream over the area. A,.
where the average concentration is
denoted by C,. Physically, C,
corresponds to the average of the actual
concentration, which is a Gaussian
distribution over the effective flow area
A». If the ground water seepage velocity
is V,. then the contaminant mass^lux
exiting the ground water system into the
stream, m,. is given by:
plume affects the concentration, but not
the total mass loading to the stream. At
steady-state, only chemical
transformation reduces the mass
loading.) Combining equations (A2)-
(A4), one obtains:
(A5)
fHQLC
which may be expressed as:
(A6)
where
(A7)
where:
QL=rate of percolation through the land
disposal unit. m3/sec
P=average annual precipitation rate, m/year
fR=runoff fraction
Aw=surface area of the waste site, ms
K,=total effective decay constant in ground
water, years"'
T, = time taken by the contaminant to travel
from the land disposal unit to the stream
entry point, ysars
Values for K, and Tc can be
calculated just as in the ground water
analysis. For those chemicals that
hydrolyze, K, is equal to the overall
hydrolysis rate constant given by
Equations (B23) and (B25) in Unit
III.A.3.f. The travel time of contaminants
in ground water is given by:
(A10)
(A3)
where Qc is the contaminated ground
water discharge rate. At steady-state.
the quantities mg and mi. are related by:
(A4) m0=fHmL
where fH is the fraction of the
contaminant mass not transformed by
hydrolysis or initial speciation in ground
water. (Note that Equation (A4) is the
consequence of mass conservation.
Lateral dispersion of the contaminant
Equation (A7) gives the required
expression for the dilution factor due to
transport in ground water. The
parameters QL and fH may be estimated
as follows:
(Aft)
and
(A9)
P(1-fa)A,/(86400 . 365.24)
exp(-KQ.ya )
where;
X,=distance from site to stream, m
V,=ground water seepage velocity, m/yr
fo,=fraction of compound that is dissolved
(see Equation (B16) in Unit HI.A.3.f.
For metals, fH represents the fraction not
precipitated upon entry to the ground
water.
As the contaminated water from the
ground water system enters the stream
along the side and bottom, it mixes with
surface water supplied by the upland
watershed as illustrated in the following
Figure 11:
BILLING CODE 6560-50-H
-------
^
o!
t
LAND DISPOSAL
0g
AVERAGE
CONCENTRATION.
CX=C8
x=o
x=o
DISTANCE. X
FIGURE It —GROUND WATER LOADING TO THE STREAM
SHOWING MASS BALANCE AND CONCENTRATION PROFILES
8M.UNQ C006 6S66-SO-C
-------
' 1668 • Federal -Regisie^Volv 51V No;- 9 f Tuesday; January 14. 1986 / Proposed Rules
Lateral mixing spreads the .
contaminants until lateral concentration
gradients disappear. The laterally
averaged concentration, d, increases
with increasing distance reaching a
maximum near the downstream edge of
the contaminated ground water plume,
where x=0. At the section where x=0,
Cx corresponds to C, and can be
calculated by a single mass balance.
Assuming no in-stream degradation, one
obtains
(A11)
QSBCS
(A16)
QS-P(1 - fB)As/(86400 . 325.25)
where A. is the surface area of the
stream watershed. It is assumed that the
average annual precipitation rate, P, and
the average runoff coefficient, fR, are the
same for the waste site and the entire
watershed. Combining equations {A15J.
(A16) and (A9) gives
(A17) c;
where Aw is the surface area of the
waste disposal unit.
ii. Transport due to continuous ground
water loading. The laterally averaged
concentration at the downstream edge
of the ground water plume (x = 0) is Cs
(see Figure 11).
At a given measurement point located
at distance x from the edge of the mixing
zone, the concentration will quickly
reach a steady-state value and this
value will be approximately the same as
the laterally averaged concentration.
The steady-state, laterally averaged
solution for concentrations at the
measurement point, £T, is given by:
which can be rearranged in the form
(A12)
(A18)
e
where Q». is the stream base flow at
x=0. and £. is the initial stream dilution
factor, which is simply the ratio of the
contaminated ground water flow to the
stream base flow. Combining (All) and
(A6) yields the relationship of C, and CL:
(A13)
Cs =
(A19) where 3 = K-X7U
K = decay rate constant, sec
-1
U = mean downstream velocity, m/sec
which upon substituting for £, and
gives
(A14)
r = °
Cs ^F
or
(A15) Cs
Q_J,
C>
For calculating bioconcentration in
« Scenario 2 or chronic toxicity in
Scenario 3, we assume that the fish
' reside continuously in the upstream area
where the effect of degradation is
insignificant (x=0). Therefore, in this
case, £T, is 1, and C, becomes Cs.
C L iii. Delivery of contaminant through
drinking water. Drinking water plants
take in raw water at a distance, x,
downstream from the point of discharge.
As a minimum requirement, it is
assumed that in any drinking water
plant the raw walei* having contaminant
concentration Cx is treated by allowing
suspended solids and absorbed
chemical to settle out. This leads to a
reduction of concentration from Cx to
CDW- The relationship between CDW and
Cx is given by Equation (A20) with £DW
being the dilution factor corresponding
to the fraction of the compound that is
dissolved, fD.
Note that QL is given by Equation
(A8), Qu, is given by
(A20)
The expression for fD is developed in
Unit III.A.3.C. This may be written as:
(A21|
i
I * 0.41K0. • <
10 •
where.
K,,w=octanol-water partition coefficient.
/oct/Avater
foc=organic carbon fraction of sediment
S=sediment concentration, mg/1
(4) Delivery of contaminant through
fish. Dissolved neutral organic
compounds in the water can be taken up
by fish through exchange across the. gill
• and gut membranes, and through the
skin. Contaminated food can be
ingested, resulting in further exchange of
compounds across the gut membrane.
Concentration levels in the fish will rise
until the activity of the compound in the
blood equals the activity of the
compound in the water. This condition
represents chemical equilibrium. Further
uptake of the compound resulting in
higher blood concentration will lead to
net exchange out of the fish through the
-------
Fedarat Regigter- A
Einday. Janu«y*l»t S986 /< Pfopwed Rules
Iflftt
gill, gut, kidney, and skin. Consequently,
any chemical buildup above the
equilibrium level is controlled by the
relative rates of ingestion, metabolism
and exchange. If gill and gut exchange is
rapid compared to metabolism, the
equilibrium concentration will not be
exceeded, and
(A22
B
fnC
where CB is the dissolved concentration
in the blood, expressed in mg/1, and fD is
the fraction of chemical dissolved. Note
that fD is assumed to be the same as £Dw
given by Equation (A21).
If the fish is exposed to steady
aqueous concentrations over a long
period of time, the distribution of the
compound within the various fish
tissues will equilibrate, so that:
(A23a)
B
and
(A23b) Cn/-Kn/CB
where:
C/=lipid (or fat) biomass concentration,
mg/kg
K/=lipid phase partition coefficient, //kg
Cni=non-lipid (blood, muscle) biomass
concentration, mg/kg
Kn/=non-lipid partition coefficient, //kg
The average whole fish concentration
CP (mg/kg) is the weighted sum of the
tissue concentrations:
(A24) CF
where 6= fraction of biomass that is
lipid.
Substituting Equations- (A 22) and (A 23)
into (A 24) gives:
(A25) Cp-kffC,
where KP is the entire fish partition
coefficient, or bioconcentration factor
given by:
(A26) KF - K£ f£+ Kn£ (1 - if )
Equation (A25) reduces to Equation
(A20) provided that the parameter t,t is
defined as:
(A27)
• Note that unlike the dilution factors,
£F is not dimensionless. The units for £p
is I/kg. For strongly hydrophobic
compounds, lipid storage dominates PF.
The lipid phase partition coefficient can
be replaced by the octanol-water
partition coefficient, so that,
approximately:
(A28)
= ^ow •
For less hydrophobic compounds, KJ
may contribute significantly to KP. Non-
lipid tissue is composed primarily of
water, along with protein and
carbohydrates. Assuming that
partitioning to non-lipids is always less
than or equal to 1 percent of the
partitioning to lipids, a conservative
estimate of KF is approximately (Ref. 5):
(A29)
= K
ow
For highly polar compounds and
metals, the bioconcentration factor KF
can not be estimated from the octanol-
water partition coefficient and lipid
fraction. In this case, observed field or
experimental values of KF must be used
directly.
(5) Direct Exposure of Aquatic
Organism. If contaminant
concentrations axe high enough, aquatic
organisms may suffer chronic toxic
effects. Water Quality Criteria have
been established to protect against these
effects. The derivation of the Water
Quality Criteria is discussed in Unit
III.A.l.g. These criteria specify criteria
concentrations, durations of averaging
periods, and frequency of allowed
excursions. Only permitting an
excursion once in 3 years implies that
the criteria were developed based on
low flow conditiens when dilution of the
contaminated plume is least. During
these base flow conditions, both stream
flow and leachate flow are proportional
to average precipitation, as described by
Equations (A8) and (A18). Consequently,
lower average j-ainfall will produce both
lower stream flow and lower leachate
flow, resulting in a constant dilution
factor. While the presence of sediment
in the stream causes a slight reduction
in the dissolved concentration due to
sorption, it may also cause faster uptake
of the chemical by fish. The net effect on
toxicity is not clear. Because of this, and
the fact that criteria are designed for
total, not dissolved concentrations, the
exposure concentration, CEXK will be set
equal to the stream concentration C»:
(A30)
'EXP
Where £EXP is the dilution factor for
exposure of aquatic organisms to stream
concentrations. Consequently, a
concentration that will not be exceeded
more than one in 3 years will
nevertheless be equalled often in a 3
year period. Thus, the stream may
approach chronic toxicity conditions
and leave little margin for error hi the
stream criteria. It may be advisable to
back calculate allowable leachate
concentrations using a fraction of the
stream criteria number..
f. Adyection, dispersion, and chemical
transformation in stream. In this unit
procedures and formulas for estimating
physical parameters of advection.
dispersion and chemical transformation
in surface water are presented.
i. Advection. A compound introduced
to a water body will be advected
downstream with the bulk water at
mean velocity U such that
-------
Vfr** ',S£U~
where:
Q=atTE2m flaw, .mf/tssc
B=8tieam widlh, m
d=mean stream death,
Fora given flow.in a specific stream
reach, width,idepth, andvvelocity aie
relatediempiricallytby.thfi fbllowiqg
equafions. (Hef. 5):
d=cQf
'
,{B2a)
(B2b)
(B2c)
where'theTuim'Bff'fhre escpoirents
(b+ffnf) ana/flre-proauct'oT'the
AlthrjUfh'tiiBorefical'eonsifierafions
predict that
-------
Federal Register,/. V TIOAL
ESTUARIES
10A0
Afirltaln
• U.S.A.
• Malayala
APuarto Rico
FIGURE 12 — TRI-AXfAL GRAPHS OF AT-A-STATION
HYDRAULIC GEOMETRY EXPONENTS
BILUNO CODE 6560-50-C
-------
1872
groproed Rules
The stream base flow for
subwatersheds.tQo, can be calculated
from the relationship
(B3) Q0=As.q
where c=average flow per unit area
mj/sec
Velocity at basfiflow, U0, can be
calculated by Manning's equation:
(B4)
U - H 2/3
4o - Q0 ,.
where:
d,=depth baseflow, m
s=channel slope, m/m
n=Manning's roughness coefficient, sec/m*-3
Ths width atibaseflow B0, can be
calculated from U01 d,,. and the baseflcw
Qo using Equation (Bl) rearranged:
(B5)
= Q0/(U0-d0)
The stream flow during a-storm
includes both haseflow and runoff.
(B6)
+A.P25fr
Given the baseflow values B01
and Qo and the!Stormflow value Q, the
widths, depths,;and velocities for -
stormflow conditions can be calculated"
as
= B0 (Q/Q0)"
= d 0 (Q/Q „) '
When the theoretical values
hold. U increases with Q to the % !
power. A tenfoldlncreaae.in.flaw, ihen,
results in a doubling of velocity.:
Streamflows and the associated
hydraulic variables, than, can lie
synthesized from distributions of
-.,,,
channel slopes s, channel roughness
factors n, precipitation totals Pus, runoff
coefficients fR, and the hydraulic
geometry exponents b and f.
ii. Dispersion. A compound advected
through a water body will be mixed
vertically, laterally, and longitudinally
from areas of high concentration to
areas of low concentration. The rate of
mixing is proportional to the
concentrationjjHulient aad either a
turbulent mixing coefficient or a
dispersion-ctwffficieiit. A turbulent
mixing coefficient in rivers is
proportional to the length scale d and
the intensity of turbulence, which is
represented by the shear velocity:
Whete:
e= channel sio]fce
d=meamd«pth,
V
, m/sec
g • d • s
. m/sec*
Becauae vertical mixing in streams
ocons-vBiyqunddy.-we assume
comftetam-dmiing the initial dilution
fltase. 'Lateral-mixing .is -most important
in thfijiear field. It is-amallest for
uniform straight channels, and increases
with-ourves and irregularities. Fischer et
al. (Sef.,44) suggesl^alcuteting the
lateral diffusion coefficient as:
'(B9)
0:6 * cj < U', i 50%
The pnpor&onality factor can vary
gcaei anyauuch smaller ihan shear flaw
dispenion, which is caused by velocity
gradients. Fischer et al. (Ref. 44) suggest
calculating the longitudinal dispersion
coefficient with the approximate
retetien&ip:
(B1Q) £X= 0.11U2 . B2/d . U"
•Here.vagain./fhejisqportionality factor
icanwary ±130 peicant.
iii. Cheaiicctt'Tfransformation. A
compound'tranBportaa.through a. waiter
bodycan undergo several physical and
Fast
are treated by assuming local
equilibrium conditions. Sorption is
considered toJbemtwjailibrium wifti
desorption:
Where:
S'=sediment concentration, kg/1-
Cw=dissolved aqueous concentration, mg/1
C,=sarbed;aQncentration, mg/I
The haaal equilibrium concentrations
Cw-andCi areflBsrernad by the
jequiliirium jfistrttmtion coefficient K.
It hae been shown that for sorption of
hydrophobic organic.oompoandfi:
K
OC
.Where:
Koc=Drganic carbon partition coefficient, I/kg
toe= organic caibon fraction of sediment
with Kow
(Ref. 65):
(B14) K
OC
Q.4iJK
ow
Comhiriiog-Eoiiations (B12)-(B14) and
teacranging teime gives an expression
^or thefraClion ofthe compound that is
dissolved:
.1 . 41.. K3.
The soAed'chemical fraction f, is equal
to 1-f,,.
Thetfcacfion of the compound that is
dissolved in-ground water can be
calculated from an equivalent
expression:
fS18l-
0*1 •
where: - •
o,=voluiaetric water content of porous
, medium, • ,
foc»=organic carbon'fraction of porous
medium
pk,=-bu!k density«fH)orQUB-medium. kg/1
and
-------
9671
J *fitfl. J*. jftiB.a> ff gjaarttey,
The seaoad termjn Equation^B26>
represents Hie conductivity of the
compound through a liquid and a gas
boundary layer at the water surface.
The liquid phase resistance to the
compound:is.assumed*ob,jrthe gas phase only:
(B28)
WAT
18-tnw
where:
WAT=water vapor .exchange constant (m/
sec)
18=molecular weight of'water
H=Henry's law constant (atm-m3/mole)
R=ideal gas tronstant=8:206xa(r%i3-atm./
mol^K
T=water temperature'f°K=2/3-fT.
The reaeration and water vapor
exchange constants will vary with
stream reach and time of year. They can
be calculated using one^tif.'seineral
empirical formulations. TheTeaeration
rate constant will be caiciilated'.by dke
Covar method using stream velocity, U,
and depth, d, then corrected for
temperature T (Ref. 35). The water vapoe
exchange constant will!be10 ~> • W
where:
W= wind speed at 10 cm above surface,(m/
sec).
Wind
can be adjuotetiite-the-aOfcm&eight
assuming a logarithmic velocity profile
and a roughness height of 1 mm'fRef.
62):
HB3Q) ,w
where:
W,=wind speed at height z (m/s)
Z=wind measurement height (m)
In summaajf. ;thiae itraosfannation
analysis: sogition, hydrolysis,- and
vt»laHlizaiion,-Sarption of hyflrophobic
organic compounds 'is calculated 'iy
Equation (B15) using data for'Ko., fowl
and s. Sorption of metals is jcalculated
by WIBTTHQ using data fer jfll, T,
alkalinity or TIC, DOM, major cations
and anions, and metal partition
coefficients. Hydrolysis is calculated by
Equations (B22) and^B^) .using data Jer
-
(B30)tts«ig-aateJfor4«r,-a,'W,T,1*rW, and
H. When insufficient data are available,
conservative analyses can be completed
by ignoring any of these processes.
g. Notation for equations in Unit
A, area "through which contaminated '
groundwater flows into stream, m8
As surface area of stream watershed
above entry of leachate to stream, m2
Aw surface-area
B stream width, m
C concentration of dissokifid
contaminant, mg/7
CAD! acceptable. 3a% infafln.
concentration, mg/7
C'AD, acceptable daily intake fish
concentration, mg/kg
CCC criterion continuous
concentration to^protact aquatic life,
dissolved concehtarfion in fish
fcfeod. ivfV
CDW concentration of dissolved •
contamination drinking water, rng/J
Cr averageJjioaccumulation
_ contaminaat in fish, mg/kg
C, average^oRcentrafion-acress
contaminated area of interception
between groundwater system and
stream, mg//
C| lipid.(fat) biomassjconcentration in
ifiahiiie«uee,iing/«kg
CL concentration of contaminant in
leachate, mg//
Cm non-lipid (blood, muscle) biomass
.
Cs average concentration of
contaminant in the mixing zone
adjacent to the stream entry point,
mg// '
Cs sorbed concentration, mg//
Cx £Qncentratiflnat distance x
downstreamifrom the stream entry
point, mg//
d mean stream depth, m
dt impoundment depth, m
d, -impoundment freeboard required to
contain a 24-hr, 25-hr storm, m
d,, mean steam :depth at feawe flow, m
E, iongihidinal dispersion .coefficient,
m2 I SBC
£, lateral dispersion coefficient, m2 /
sec
E longitudinal dispersion
E' longitudinal dispersion
factor=(4E][(t-tr))1/2
[E]j environmental property for pracess
"i*
f
geometry
fo feaction_df iitmtaminanttltart is
dissolved
fh fraction of contaminant mass not
transformed by hydrolysis or initial
speciation in groundwater
fi fraction of fish biomass that is lipid
foe 'Organic carimn fcatotion of
SHSpendefl-Beiimant
f
-------
Federal Register / Vol. 51, Met, ft / Tuesday, January 14, 1988 / Proposed Rules
%, - 2.65(1-0g ) (817) (B19)' R.ak.
• f0- C
(B21) K « ZK,
The sorbed chemical fraction f.. is equal
to !-£„..
Slower chemical transformation
reactions can be treated generally by
using mixed second order kinetics [Ref.
13):
Cw + [EJ. -* p (B18)
where:
lE]i= environmental property for process "i"
^transformation product, mg/1
The reaction rate R, (mg/l-sec) for
Process "1" is:
where:
ki=aecond order rate constant for process "i"
Yi=yield coefficient for process "i"
C=total concentration of compound (mg/1).
Given a local value for [E]Jf a pseudo-
first order rate constant KI (sec."') can
be calculated:
(B20) K-k, [Eh-Xfn
For a compound undergoing several
competing reactions, the overall pseudo-
first order rate constant K(sec. -«) is
This general second order reaction
method can be used to predict reaction
rates for photolysis, hydrolysis,
oxidation, and bacterial degradation.
For short reaches of rivers with travel
times of hours, these reactions are not
likely significant to reduce instream
concentrations. For transient loads
during storms, darkness should further.
reduce photolysis and, indirectly,
oxidation. Bacterial communities are
unlikely to acclimatize within hours to
the transient loads. Of these
transformation reactions, then,, only
hydrolysis will be considered for those
fewxompounds with large rate
constants. The hydrolysis rate constant
is calculated from the acid-catalyzed,
neutral, and base-catalyzed pathways
(Ref. 5):
(B22) KHO - K
HA
a f. + fD) + KHN + KHB [OH'] fD/3600
where:
kha»= second-order acid-catalysis hydrolysis
rate constant (I/mole-sec)
compound=10
8 ra£l
sorbed
lOH-]=hydonium ion concentration
(mole/1)
pOH=stream POH=14-pH.
- —-— ———-—--- \-i ...—• - — ___, J/V^A * — a u o««ij. jj^^**—XT—J/A AI
[H+J=hydrogenionconcentration=10"I>H Khn=neutral hydrolysis rate constant (sec-1) c,M, , . ., . .
fmole/U kxK=second-ord(»rha»B.rfltai««-ahv^i,,»i« . For ground water, the nominal
—rf —-—o—.
(mole/l)
pH=stream pH
.,, . ., . .
khb= second-order base-catalysis hydrolysis groun water the nominal
rate constant 0/mole-sec) hydrolysis rate constant (in years - *) is
calculated from an equivalent
expression:
(B23) K
QO (KHA [H +]fl(a • fag +
where [H * Jg - hydrogen ion concentration = 10~PH?I
pHg » ground water pH
[OH"]8= hydronium ion concentration = 10~P°H9
pOHg - ground water-pOH = 14~PH9.
f0g(24)(365 • 25)
: ,
K>-K* •«» [">' • f -r .'
W9.. .r ,273
'
The nominal hydrolysis rate constants
KHO and K,,, apply to a reference . 1K
temperature^ TB (usually 25 °C). These
can be corrected to ambient surface or . •
ground water temperatures (T or Tt)
with the following expressions: A final transformation pathway to
consider is volatilization. The
S24) K .K U' • I -- - — - 11 volatilization rate constant K, (sec"1)
can be calculated from the Whitman, or
two-resistance model (Ref. 5):
1
(B26) Kv =
d HL -i- P
where:
d=river depth (m)
RL=liquid phase resistance (sec/m)
RG=gas phase resistance (sec/m).
-------
1676
Federal Register / Vol. 51. No. 9 / Tuesday. January 14. 1986 / Proposed Rules
i. Emissions. Air emission models are
specific to waste disposal unit type and
require waste characteristics,
parameters describing the unit (such as
surface area), and meteorological
parameters as input. The output of the
model is an emission rate. EPA will
develop an emission model for each of
the following unit types: waste piles.
surface impoundments, landfills and
land treatment facilities. Other land
disposal units, for example salt beds,
will be evaluated to determine whether
they are a significant source of air
emissions,.
To select the appropriate emissions
model to be used to calculate screening
concentrations for air exposure, EPA
will conduct an analysis to screen these
models. Each land disposal unit type
will be characterized in terms of both
emissions and area. The potential
human exposure will be determined for
each land disposal unit type and
compared.
ii. Dispersion. Atmospheric dispersion
models relate the emission rate of
hazardous constituents at the source"of
contamination to the ambient air
concentration at the downwind receptor.
These models are specific to emissions
rate, physical configuration, meterology
and distance from the contaminant
source to the human receptor.
Because the reference dose used by
EPA as the exposure concentration for
the downwind human receptor is a daily
exposure, hourly meteorologic data will
be used to back calculate the
equilibrium constituent concentration in
the air phase at the air/land-disposal-
unit interface. As a result, EPA will use
the Industrial Source Complex Short
Term Model (ISC-ST) as the dispersion
model for analyzing exposure via the air
route. The ISC-ST model is listed as the
preferred model in the revised Guideline
on Air Quality Models. The original
guideline is incorporated by reference in
40 CFR 51.24 and 52.21. The December. 7,
1984 rulemaking (49 FR 48018) proposed
to replace the original with the revised
guideline.
iii. Monte Carlo approach. EPA plans
to use a Monte Carlo approach for
determining screening concentrations
for exposure to air contaminated with
hazardous waste constituents. The
Monte Carlo simulation technique
combines the variability in emission
rates with the results of dispersion
model computations. This technique
simulates the effect of random
variations in input variables by
randomly selecting values from an
appropriate probability distribution and
accumulating results over many samples
to obtain a picture of the form that a
long-term series of results should take
(i.e., a probability distribution of
equilibrium concentrations in the air
phase at the air/land-disposal-unit
interface for each constituent).
c. Volatilization test procedure. The
output of the air modeling described
above will be an equilibrium
concentration for each hazardous waste
constituent in the air phase at the air/
land-disposal-unit interface. This value
would become the screening
concentration for air exposure.
In order to enable a comparison of the
concentrations of volatile constituents
from an actual waste to the screening
concentration determined for air, the
Agency is developing a volatilization
test procedure. This test is an analytic
method designed to determine the
equilibrium concentration of volatile
hazardous waste constituents emitted
from the waste into a static head space.
A sample of a waste would be placed in
a test apparatus designed to capture the
volatile constituents of each' waste. The
equilibrium concentrations of these
captured constituents would then be
analytically measured and compared to
the screening concentration.
d. Determination of distance to
potential point of exposure. In
performing the ground water back
calculation procedure, a distance is
selected representing a point of
potential human exposure. This distance
represents the point at which human
exposure to constituents in ground
water could occur through ingesfion of
drinking water. As discussed previously.
selection of the distance is based on the
concept of effective control.
Although a distance of 500 feet has
been selected as the potential point of
human exposure for the ground water
back calculation model, this distance
may not be appropriate for calculating
human exposure through the air. As
noted in Unit III.A, the distance used in
the calculation of screening
concentrations for ground water
represents the area of effective control.
It is presumed that owner/operators
can, at a minimum, effectively control
access to ground water within this area
and thereby prevent human exposure to
unacceptable concentrations of
hazardous constituents in ground water.
When applied to an analysis of air
emissions, the concept of "control" may
be very different. Unlike the ground
water area, one cannot control exposure
simply by owning the land and
prohibiting the drilling of ground water
wells. In order to "control".exposure to
air emissions, options such as
mandatory mask requirements or
ingress restrictions should be
considered. Existing RCRA regulations
at 40 CFR 264.14 already require that
warning signs be posted at hazardous
waste facilities and that measures be
taken to avoid unauthorized entry onto
the facility. In deciding upon the proper
exposure point, it is also important to
note that EPA is concerned about the
health and safety of facility personnel.
"RCRA's mandate to protect human
health and the environment is not
limited to dangers occurring outside
hazardous waste management facilities"
(45 FR 33184 (May 19,1980)).
e. Timing of air component. EPA
intends to propose the air back
calculation procedure as soon as
possible. Most likely, it will be
published with the proposed rulemaking
addressing the California List. If, based
on the proposal, it appears that the
treatment standard for any of the
solvent or dioxin-containing wastes
subject to the November 8,1986
statutory deadline, will be driven by the
screening level calculated based on air
exposure, necessary adjustments to the
treatment standard will be proposed
and every effort will be made to issue
final standards by the applicable ban
effective date. It is also possible that the
concentrations calculated based on the
ground water and surface water
components will be at a level that also
provided protection from exposure via
the air.
EPA is also analyzing other possible
effects, such as ozone effects, resulting
from emissions of hazardous
constituents from land disposal facilities
in conjunction with the statutory
mandate of section 3004(n) to
promulgate regulations for the
monitoring and control of air emissions
at hazardous waste treatment, storage.
and disposal facilities, as necessary to
protect human health and. the
environment. EPA believes that section
3004(n) is a more appropriate authority
for considering effects, such as ozone
effects, that are influenced by the
cumulative waste management activities
. that may occur at the facility. Under
section 3004(n), the Agency can consider
all waste management activities that
may contribute to air emissions,
including activities like waste transfer
operations and non land-based
management, that are not covered by
the land disposal restrictions program.
B. Determination of Best Demonstrated
Achievable or Available Technologies
and Performance
This unit describes in more detail
EPA's proposed approach to evaluating
alternative treatment technologies for
hazardous wastes otherwise prohibited
from land disposal. The purpose of this
evaluation to to determine which
-------
groundwoterv j/
from land - .
•P mass- loading rata tcr. stream= {com.
surface runoff, .g/aetc
MW molecular weight of. compound
n Manning roughness, coefficients
[OH~] hjrdronium ion,
concontration=lCP-oH mole//;
PH stream pH-
p"» groundwaterrpH.
p°" stream-pH
p°Ht groundwater-pOH.
P transformation-product; mg$
P average, annuaLpreciflitationnn.
PM averagaprecipitadon«fi)B2Sryear,.
24-hour atonnv.m>
q averagB,frow,perunitaiea^m.?/sfie/
ma
Q stream.flbw..m;r/iBE.
Qc, contamihatEd'groundwatet •
d!8charge,.m?$sec-
Qt rate of Der.colatran-tEraugB.tne. fend'
disposal., m'/sec.
Q" storm runofffTowv m.r/sfifi.
Q*n fTow rate of spilL'delrvered to. the
Qi stream. flow, nr^/sec
R ideal gas constant; S^Offxur*
.
RO gar phase resistance, sec/in^
RI reaction rate for process- 'T,
sec-
RL ffqjifd'phaae-resistance-, sec/in
s channel slope
S sediment concentration; mg/£'
S' sediment'concentratibn. Kg/iP
t time sincebegirmihg'of diselisrge; sec
tn time duration of the contamihanf
.loading, see
T water temperature,. *C
T water-temperature;. *K=27^KF
U mean downstraami&duective.-
^vjdacity. m/iec-
U* shearvskwrftsfj m/3«c-
V, groundwaterseepage-verocitytra/.'
year
W wind speed: at laemsabjweaurfaOTf
m/sec-
WATT waterrvaporexckange'eanstaiit;-
m/sec
Wt wind apeed-atlieqattc.iB/sBc-
x downs treantdiaiamatiiraar.
discharge,, m.
a acid-catalysis hydrolysi»Tate
enhancement factor fee sorBed:
compound!
& kinetic reduction.exponent = K« xf
& exponent in>RJanesonrce equation,
— xw/2^,,
w adveotive-disperaien.fafitor^m/tec.
IEXF aquatio.expoeora fector
?DW of rwe
processes whidr-are-mBdeled'ih
differentwaysv PfrstiB the'proeess-by
which.CMTtanrinantS-are-released'fronY
the landdisposat uniPto the stmospfiere;
and secBHtf^iB-'tfle-rofasBquent'dispBi'sibn.'
as the contaminant'is1 transported to the
pouit of exposure; fe-order to caJcufate
the equifiBrftnn-concenttatfons of1"
haBradbus1 waste-constltnentsin the-air
pKBse-afnWair/land-disposaPunit:
interfacef.tfie-^gency is evamatfhg-BotH
emissibns"aHtf'dispersibn'mode!s.
-------
1678
Federal Register / Vol., 51, No. 9 / Tuesday, January 14, 198Q / Proposed Rules
bench-scale data may also be used to
further support full-scale data. Where
experimental data do not exist for some
waste or constituents, EPA may choose
to base the determinations of which
technologies are demonstrated (as well
as the performance evaluations) on
similarities in waste or constituent
physical and chemical properties.
In most cases, data do not exist
showing that all wastes and constituents
within a waste group can be treated by
a specific method. This is because the
Agency does not have sufficient data to
characterize completely either wastes
that appear to have similar treatability '
or the treatment of such wastes. EPA
may rely on the similar physical and
chemical characteristics of wastes to
determine if a treatment technology
applies to an entire waste group. EPA
will make the best determination
possible as to the applicability of a
treatment technology taa waste group
and its constituents based on available
data, and will present all pertinent data
in the preamble or background
documents.
If the only data available on treatment
of some wastes are from pilot- or bench-
scale operations, then it is unlikely that
any existing full-scale operations are
designed and operated to achieve the
limits. In these cases, although the
Agency will establish a treatment
standard based on experimental data.
alternative capacity will probably be
insufficient. Therefore, EPA is likely to
grant a variance to the effective data of
the land disposal restrictions. This
variance will allow additional time to
provide the full-scale facilities with the
proper design and operation required to
meet a treatment standard. Unit III.E
describes the methodology for capacity
and effective date variance
determinations. ,
3. Criteria for "Available" Technologies
a. Proprietary or patented processes.
Proprietary or patented processes will
be considered available if EPA
determines that the method can be
purchased from the proprietor. However.
if the technology is a proprietary or
patented process that is not readily
available. EPA will not consider the
technology as available for determining
BDAT. Exclusion of such technologies
from EPA's analysis may result in a less
stringent treatment standard. All
commercial facilities using proprietary
methods will be included in the capacity
determination discussed in, Unit III.E.
The services of the commercial facility
offering this technology can often be
purchased, even though the technology
itself cannot. In all cases, the technology
is available to treat wastes'generated by
the owner of the proprietary process.
b. Treatment technologies that
present greater total risks than land
disposal methods. EPA will evaluate the
risks associated with treatment
technologies relative to land disposal
methods. Those technologies that are
found to present greater total risks than
land disposal of the untreated waste
will be excluded from (i.e., considered
"unavailable" for) the determination of
best demonstrated achievable
technologies. All demonstrated
treatment technologies will be included
in this analysis. Also included will be
technologies that are not demonstrated
for a waste group, but that are methods
EPA estimates may be capable of
achieving the treatment standard for
some wastes within the groups. Because
these technologies would be used in
some cases to meet the treatment
standard, an analysis of the total risks
associated with their use is important.
Unit HI.C explains hi detail the
methodology for performing this
comparative risk assessment.
A technology may be demonstrated
for more than one group of wastes. The
comparative risk assessment may show
that the technology poses greater risks
than land disposal methods for only one
of these groups. In this case, the
technology would still be considered
"available" to treat wastes in the other
waste groups, and therefore the
technology would be considered in
determining BDAT for these groups.
If no treatment technologies present
fewer risks than land disposal for a
particular waste group, the Agency will
not set a technology-based treatment
standard. If capacity of alternative
recovery and disposal technologies is
also insufficient, alternative capacity
will not be available, and the Agency
may grant a variance (i.e., extend the
effective date of the ban for up to 2
years) to allow sufficient time for the
development of adequate technologies,
additional standards to control the risks
of existing technologies, or alternative
protective recovery or disposal capacity.
(See Unit III.C for an explanation of
additional standards and Unit III.E for a
discussion of effective date variances).
c. Substantial treatment. In order to
be considered available, treatment
technologies must "substantially
diminish the toxicity" of the waste or
"substantially reduce the likelihood of
migration of hazardous constituents"
from the waste in accordance with
RCRA section 3004(mj. By requiring that
substantial treatment be achieved in
order to set a treatment standard, the
statute ensures that all wastes are
adequately treated before being placed
in or on the land, and ensures that the
Agency does not require a treatment
method that provides little or no
environmental benefit. Treatment will
always be deemed substantial where
the technology can achieve the
protective screening concentration
levels. In addition, treatment methods
will be considered substantial if they
result in nondetectable levels of
hazardous constituents of concern in the
residuals. Therefore, EPA will evaluate
only whether or not a treatment
technology is substantial when it is
contemplating technology-based
standards, and the technology does not
achieve either the screening
concentration levels or nondetectable
constituent concentrations. EPA will
make these determinations on a case-
by-case basis considering the following
factors:
(i) Number and types of constituents
treated;
(ii) Performance (concentration of the
constituents in the treatment residuals);
and
(iii) Percent of constituents removed.
For instance, in considering percent
removal for some wastes, such as those
containing high concentrations of
constituents or those
-------
treatmentrnerhods are-tfie-Besir
demonstrated fdrrreating. these
hazardous wastes; andittr determine the-
performance thatis-acHievetfby these
methods. BOAT arrd-its performance-
must be established'so-that the-Agency
can develop treatment'standards for
hazardous wastes in accordance-with
the regulatory framework described in-
Unit Hi As discussed in Unit II,1 and
stated in RCRA section 30G4tm#
treatment methods "shouId'suBstantially
diminish the toxicity oPrfie waste or
substantially reduce-the •likefihoenf of
migration of hazardous constituents'-
from the waste." AIso< tne>"levels and1
methods of IreatrnentestabnshebVBy the-
Agency should be the best'thathave
been demonstrated t&-be'achjevable."
(Vol. 130 Cong; Rfec; 5917$ Jitty 2K 1984:]
1. Waste Treatability.. Subgroups.
Because of the large number and
variable nature of the wastes within
most EPA waste codes, it is usually not-
appropriate-to evaluate treatment!
methods- and their effectiveness on-a.
waste code basis. Rather, in most cases.-
EPA will divide wastes.into treatability
subgroups based on similar physical and
(.hemical properties. Factors-that will be
considered in establishing these
subgroups include physical.and
chemical properties such.as pH-and heat
value. For instance, one waste group
may consist of acidic.wastes of.pH less
than or equal to 2. and another group
•n-iy contain basic wastes of.pH-greater
than or equal to 12.5. The heat value of a
Witste determines whetherrthe waste
can be used as a fuel substitute or
incinerated, and usually depends on the
concentration of organic-constituents^
the waste. Wastes may, also be grouped
according to the constituent properties
nince these properties influence waste
ti'«atability-.For example, allwastes
containing volatile organic constituents
may form one treatability group..while
wastes containing soluble organics may.
toim another group. Other groups may.
ronsist °f wastes containing metals or
cyanides.
All of the waste groups described-
above may require-furtKersuBdivision
according to constituent-concentration.
Wastes containingKigfrconcentrations-
of solvents may be amenabTe-to
distillation, whereas wastes-containing
lower concentrations of'tHe same
solvents may-require steam or air-
stripping. Pfiysieal'form (i.'e;, liquid;
sludge, or solid) also influences
treatability. Manytreatmenrprocesses
are appropriate-only for aqueous-'or-
liquid wastesrother apply only t&
sludges or solids.
In this proposed-rttfemaking EPA1
categorizes solvent'wastfrcodterFOOT
througft FOG5 into two major treatabiluy.
groups based'on.the factors given above.
The first group;is-solvent-water, mixtures
which require-waste water treatment;
such- as steam strippihg.orBiblogical'
treatment. TKe.second'group is
comprisechof liquids; sludges, and'sotids
which-contaiii solvents; but are too
conceatrated.ortoo high in-solfds to be
amenable to wastewater treatment, ani
thus require treatrnerrt-orTecavery using,
incineration, drstiiration or fuel
substitution. Tire first group is further
subdivided based orr constituent
characteristics: ,solvent?-water mixtures.
containing Highly sohibre solvent
constituents are amenable to biological
degradation; those containing solvent
constituents-of fow soHibifiry, and'higji
volatilrfyaTe-amenable to.steam
strrppihgr and'tfhise wastes containing
insoluble (rrigh moiecular weigjit;
nonpolar) constituents;, as,represented"
by chemical isotherm data, may be.
amenable ttr-carfron adsorption.
However, if wastes contain solvent
constituents of different, properties, more
than one treatment technotegy or
segregation of tfter waste prior to
treatment maybe required:.
The data available to describe the
many and variedchararcteristics of
hazardous wastes are limited: This lack
of data limits the Agency's ability, to.
account for alt of the waste properties
that may influence treatability.
Therefore, EPA must often group many
wastes together that have some, butnot
all, characteristics in common. EPA wilt
often'rely on knowledge concerning.
waste constituents whose properties are
often well establishedl Hr all cases, trie
Agency will presenter pertinentdata.in
the preambte-or-faackgnjurrd^doctiments
to the mFemakmg-aTKfwuTreqiuest
comment and informatibrr concerning
the way in whtcK hazardous wastes are
grouped:
The legislative history, supports this
approach. Ft provides that1 treatment
determinations-da nothave to be by,
waste code, and that'trie Agency, may.
make "generic'"determmati6ns of
appropriate levels, or methods of
treatment for similar wastes. Cv"oL 130
Cong. Rec. S9T79;.Jury. 25; 1384.)
Once ERA has established, tfie waste
treatability groups, itwnT evaluate alf'of
the treatmenttechnologies potentially.
applicable, to each, waste group. EPA
will determine whicft technologies are
"demonstrated'"and:"avairabfet* to treat
the wastes.ih question. and:tfie
performance tabe expected from, sueft
tecKnoio^ies. IfBDAT'is different-far
different-waste groups, the treatment:
standards for each group may. also
differ. This situation would*occur only if
the screening,.!eve!a foe iadividual.
constituents could'notbe-achieved: for-
a 11 waste; groups. The projcedures-for
conducting.(Be evaluations, of, treatment;
technologiesita determine BOAT is
described below in.-UnitIU.EL2..
2. Deternrinatibir.of "Depmoiretrated"
Technologies
In order td determine which,
technologies are. demonstrated for a
waste group, thfeAgency will sludjf. the,
availahl&data cn.the types, of treatment
(including receding jane th'odsj, currently,-
used ta tifeat the wastes-and"
constitutents withiiiithe group. For the
purposes of EPA's evaluatioiu.a
treatment system could'be a singje unit
operation (e.g,,,inciheratibn)ror a
sequence;of unit operations [e.g.,
precipitation,,sedimentation, and
filtration)..TKerefiire^a demonstrated'
technology or metfiod"max actualry,
consist of a secies oftrEatmentunils..Ta
be cansidered'a demonstrated metRod"
for a waste treataBifiry group.,EPA must
judge that the method has been used to,
treat a representative sample of wastes-
falling within the group.
To make this determination,,EPA will
first evaluate available data-from
facilities, operating, specific full-scale
treatment technologies, and the types of
wastes that .they, treat. If the treatment
of certain wastes.or constituents has not:
been demonstrated fay any full scale
facility employing any applicable
treatment method..or if data pertaining.
to existing full-scale facilities.are
insufficient or inadequate, .EPA will
study pertinent data from pilot^scale
and bench-scale treatment operations to
determine if a-technologx. »*•
demonstrated! In this case, aiaentuse of
pilot- or bench-scaJJe.data.,EP,A would
be unable to set a technology-based
standard (because no technology would
have' been'demonstratfed for the waste-
and the health-based level would,
become the treatment standard by
default (see discussion in Unit II]},
These data may also be used ta
calculate treatment performance. For
example, EPA may consider, data, for the-
removal of a constituent from a.full-
scale operation insufficient if,the full-
scale facility was not designed to.
remove that constituentior if,',ih EEA's>
judgment, tfia facility was. opera ted to.
achieve performance short of which it .is
capable. In addition, whenno adequate
full-scale data are available for a
specific waste or constituent, but is.
available, far-a,similar constituent,.pilot-
and bench-scalkdatamay,be used.to
show that similar treatment
performance can be achieved>foc. the
other constituent or waste. Pilot- and
-------
,fjjBHBal pan
of the process Jbai BaaiUtoin the .waste, can be
taken into^ccount in estaHisKii^g
concenttation levels. — (S."Rejj. 1So. 88-284,
98th Cong., 1st sess. 17 fl983J).
EPA;is{prapoaing today .under § 268^ to
prohibit theoise of dilution as a partial
or complete substitute for adequate
treatment of .hazardous .wastes
restricted iH3milafld.diapasal. This
discussion involves only, the question of
dilution.as .treatment {oi.puiposes of
"availaW:Js whe«her-app1iea«mnrf the
technology te a'
a-GeneraLqppraosh.
.
standards._ERAJs.nQi,a^pre&siaJg any
new ppinion..nar xlidUhfi £ongiess,.on
use af'dilutiea.as.a.mBaiiB.ofsrerBBvinga
hazardous J«rasiexshaj8acietisik:.,{See 40
CFR.2ai4(ajtt),) T.he,Ap>ncy,baiieves
thai this iis jionsiBtent with. the
.
congressional ontaat-ated abave.
In.evaluating.ireatmant technologies.
EPA will,consal«^ilutMm'whidi is a
normal j)act.flfih£jttoducticaprQGess or
a flecessajyjpait jrfJie graces* .to -.treat a
waste. EEAibalieueB that^dflquate
treatment,in.ihis sense ehauldirander a
waste noflha2a£dou£,or.«hfluld decrease
theimass'of hazardous constituent
available .to the>enHiKinment through
either.remaval,,dBstrucn'an, or
immobilization. .For example many
treatment .methods require .the addition
of reagents, .whichas, in effect, dilution.
These reagents, however, .produce
physical or. chemical, changes, and do
not merely dilute the hazardous
constituents in.a larger .volume-of waste
so as to lewar the conBlrtuent
concentration.
C. Comparative -Ri3k Assessments
As introduced in Unit II, -
proposing toiuse.coBiparattve risk
ana^see asipa»t.«f slts-ewalurthin of
ttea1meirt,tBci«alogiee .wwwnjunctie
with establiahing section 300«M
.
explicitly «equiredlfay=«tahite,tli»e8e
analyses are.iimlnded.Jn*odBy'«
proposal toT!»Event rttnaiiooBinj which
regulations restricting JiattidDus wastes
from land i
treatmeifl in technologies *hat;po«e
greater risk* 'te human tfeedllh-ami the
envinmmant dan rhose'posad'by direct
land draposril..fEresrtmBiTt technologies
may be riskier feanitaiwl disposal
because of routine.releases. accidental
releases, and the fate ottheir residuals.}
As de8cribed;iHJUnaiII,«)num4ier of
criteria affect the de*e*minafhm«f
which treatmeat lechnalogiEB are
"available"-foffiiaix»eB!«f siting
treatment standatds. Airreng the criteria
considered in determining whether a
residadlsj-poses g*eaterTidks to httnian
health and-the environment than land
disposal o^fhewastein its current iorm.
This -unit describes -the-piocedures EPA
is propositjg-to -employ-in conducting
these-ojmpBrati^'e risk assessments, and
the ciheriaJBPATSproposing-to empJoy
in evaluating Hie-fBsults pf-thesE
comparative -risk assessments.
Treatment technologies, that .are
determined thfou^gh theae analyses .to
pose greater jfisksfhan diract land
disposal of a waste wiu"he fionsiderad
Vunavaflable" as a basis Jor establishing
the sactinn.30MfanjaDATtraatnu.nt
standardly me waete. Jf Jhe .besUor
most efficient, .treaimejit techodiogytfor
a waate.is.d£ifij3Hined to.bejriskifir.than
land disposaL.ihe.decision to classify.it
as unavailable-wiU have-a direct-impact
on the leuelarmethod estobiiabedas
the seciioc.3«0^mj.t£aaimantjtandaid.
The
demonstrated .anailabk.Uaatanant
technology for a waate jiialees '.'capped
off at^lyjJiQtectweiJevelfi Jdentrfied
by the baalth-faasedttiuefiboUfi
described in UnitilLA.aad Q), would
then be based upon-the capabiUtiefi-of
the nfixt.beat treatment .tetshnalogy that
does.not.pfisegieaterEMte than-land
disposaL To the extant that the next
best .treatment technology perfonns less
efficiently than the be«titechnolo«':(in
terms of the f&tfosmanae af:it» JEeeiduak
in the laadidiapoaBl^nvifBnnwotj, the
toeatraeot
Treatmenttacnnutogje6aia*«ifiedas
"unaradbiBte" tine to-Uwfir-greater tisks
may stifl.intiMrevet,,'tie^Hed:by'waBte
managefsia.oomptying -with -treatment
standards «Jcprs»«ed«8.oww tHuent
concentrations. Aawrthtigly..
regulatory controls-orprofiibltions over
the design and operation of these
conqdyhig wi* ^ie teeatewnt^tandafd
does not«e«uh in moreaeed'ns^s to
provide a basSs^or-flevelepmg such
controls orproMbitiens, but wfll -moat
likely need«tofre aBgmented'by
additional technical stadies.®^.
artemptifcj prewwilgate-necessary
regulatory aotttrols «r-prdhibHibns-on
framework are designed Socampare the
risks
-------
federal Register / Vol. 51, Nte. a / Tfosday; January 14; 1986 /-Proposed Rides
way in which substantial treatment was
defined. EPA solicits comments on this
methodology for detemining if the best
demonstrated treatment technology
achieves substantial reductions in waste
toxicity and mobility.
If even the best technology that is
demonstrated for a waste group does
not achieve substantial treatment of a
waste, the Agency cannot establish
technology-based treatment levels for
the constituents in that waste.
Therefore, if the capacity of alternative
recovery and disposal technologies is
insufficient, alternative capacity will not
be available, and the Agency may
extend the effective date of the ban for
up to 2 years under a variance (see Unit
III.EJ. The variance will allow time for
' the development of treatment
technologies that achieve substantial
reductions in waste toxicity and
mobility, or time for the development of
alternative recovery or disposal capacity.
4. Identification of "Best" Technologies
After identifying all demonstrated and
available technologies for a waste
group, EPA will evaluate the
performance of these technologies in
order to identify the best
technology(ies), i.e., those technologies
that achieve the lowest concentrations
in either the treatment effluents or in the
extracts from treatment residuals.
As described in Unit II.B on the
development of treatment standards,
EPA prefers to develop performance
standards expressed as the
concentration of constituents in the
waste extract. These performance
standards will be based on the
concentrations achieved by the best
demonstrated technology or
technologies. In defining BDAT, EPA
will normally set a single achievable
concentration for each characteristic or
constituent in the waste under
consideration. In doing so, EPA will
assure to the extent possible that the
performance data are representative of
the destruction, removal, or
immobilization of'all waste that must be
treated. The Agency recognizes that
many waste matrix variables exist that
can impact the performance of
individual treatment units. However, it
is the Agency's judgment that most of
these matrix impacts (including influent
concentration] can be overcome by
modifications in treatment that are not
prohibitive, i.e., additional unit
operations, longer residence times,
blending or equalization of wastes. EPA
solicits comments on 'this approach and
specifically solicits data documenting
matrix impacts for any hazardous
wastes, that cannot be overcome with
any available technology combination.
Although EPA will normally develop
performance standards to achieve
BDAT, EPA may specify a method as the
»treatment standard under certain
circumstances. In order to specify a
treatment method, EPA must establish
that the residuals of a treatment method
are consistently low in the constituents
restricted from land disposal. Therefore,
the design, operation, and performance
of the method must be controlled by
regulation to ensure this residual
quality. Currently, only incineration
appears to have sufficient regulatory
controls associated with it.
For some wastes, more than one
technology will be considered the best.
EPA may define a group of technologies
as the best technologies if the
concentrations achieved by several
technologies do not differ significantly.
In identifying technologies that achieve
similar results, EPA will consider the
concentrations achieved and the
uncertainty associated with the
performance data. Also, different
technologies may apply to different
constituents in the same waste. In this
case, not only will BDAT for a particular
constituent be a series of processes, but
BDAT for a waste containing
constituents of different treatabilities
may also consist of more than one best
technology in sequence.
When a listed waste is treated, the
treatment residue is still a hazardous
waste, unless delisted under 40 CFR
260.20 and 260.22. However, when a
characteristic waste is treated so that it
no longer meets a given characteristic,
the waste is no longer a RCRA
hazardous waste. For this reason, in
some cases few data are available to
document the performance of treatment
technologies when applied to
characteristic wastes. EPA will often
have to assume that characteristic
wastes have treatability similar to listed
v. astes. For instance, many metal-
bearing sludges are characteristic EP
toxic wastes. Others are listed wastes or
the treatment residuals of listed wastes.
Since the primary sources of data for the
treatment of metal-bearing sludges are
deiisting petitions, only listed wastes
are represented by the data. Data show
that EP toxic wastes are usually treated
by the same methods as listed wastes
containing metals. Therefore, EPA will
assume in this case that the
performance data for listed wastes also
apply to characteristic wastes
containing metals.
Where EPA or EPA-verified test data
and survey data are available on
technologies, they normally will be used
to determine treatment performance.
EPA is currently conducting-studies on
the operational parameters and
performance of many treatment
technologies. These studies look at
concentrations of hazardous
constituents in the treatment effluents
and residuals themselves, as well as
extracts from the residuals. The results I
of these studies will be incorporated in |
the determination of BDAT and
performance as they become available.)
If such data are unavailable,
engineering judgment and data and
information from other sources, such as|
industry, may be used. Data available
from pilot- and bench-scale tests of a
technology also may be considered. If
both full-scale and experimental data
are available, the Agency will evaluate |
the full-scale data to determine if it
equals or exceeds the performance of
experimental data. If full-scale data do |
not show equal or better performance,
EPA will consider pilot- and bench-seal^
data as described above. In these
instances EPA will, where possible,
resolve the difference in performance 1
evaluating the wastes treated and the
design and operating characteristic of
the full-scale versus experimental
equipment. Unless EPA finds adequate
support for a conclusion that the
difference in performance is related to
specific waste matrix interferences not
encountered hi the development of the
experimental data, difficulties in
operating the technology at full-scale, oi|
that the experimental data represent
unreasonably repetitive treatment, EPA |
will adopt the pilot- and bench-scale
performance as BDAT. Thus, EPA's
approach requires the performance of
the technology to be equal to the best
achieved in any representative
application. EPA solicits comment on
this approach.
When new pilot-, bench-, or full-scale I
data verfied by EPA testing and analysis
become available, EPA may modify past]
performance determinations and
treatment standards, where necessary.
In summary, EPA does not intend to
consider-data that are not representativ^
of well-designed, well-operated
treatment systems. It also does not
intend to determine the performance of
a technology based on unusually
repetitive treatment or other treatment
system designs or operations that are
beyond what the Agency judges to be
normal engineering practice.
5. Dilution as Treatment
The legislative history to the RCRA
section 3004(m) states:
• The dilution of wastes by the addition of
other hazardous wastes or any other
materials during waste handling,
transportation, treatment, or storage is not an I
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£682
finger
/ .m«a»fay.. jaaaigy 44. -3«8a / Pwposetl
(C) Management traiaa,{tfeatraent
and disposal technology qpeatfieationg),
The treatment technologic* te he
analyzed in each.of-thfivCooipaTative risk
assessments include all technologies
and combinations of technologies
identified as "demonstrated" for a waste
stream m Element 2 of the proposed
land disposal restrictions decision-
making framework.fsee Figure 1, Unit
II). In order to be considered in the
analyses, treatment technologiesantat
also achieve at least the "substantial"
reductions required under section
3004[m). Included:in the analysis of
treatment.alteEnatives ace also4he risks
associated with land disposal of.any
tieatment residuals {e.g^landfflling of
incinerator ashj. Also modeled are
routineiemissionfi from treatment
technologies, such as stack emissions
fHmvincineratori, as-well-as-accidental
releases, such as spills or fagifive
emissions.
There is a-wide-variety trf-treatment
technologies that are applicable-to the
waste streams currently land disposed
and that a*e-demonstrated'hi irseat
commercial and on-site facilities. All
such applicable technologies, atone and
in sequence, are evahiated.'For'example.
in the cuwerrf analyses, all liquid wastes
containing greater than 30 percent total
solvents are evaluated for fl)
incineration, and [2) distillation
followed by incineration of the still
bottoms resulting from the distillation
process, nvsome cases, however, EPA's
analyses in Element 2 of the program
framework have identified only one
treatment sequence as '"demonstrated"
for treatment dfthe waste at commercial
or on-sjte facilities, and capable of
achieving at a mrnrmuai-the
"substantial" reductions called for in
section 300»fm).
(D) Environmentaljparametezs. A
general evaluation of the WETjnadel
conducted during the last jrear has
revealed that the changes jn model's procedures for
specifying values fin-environmental
parameters' (e^sroimd water velocity,
soil poroiMy,, etc.) were revised'to
expand. Its capabilityto simulate -the
variability in iheraal world conditions
in which haxattious wastes are
managBdModel -was
modified*) satewJtto-drawparameler
values overrepeated-nmstfrom data sets
.
When appropriate, •parameters-wirh
correlated values -weie rmked'togefter
so that'the-model-wouJd-not select
unrealistic Tjr-rmpossrble combinations .
of values'roHts-mput raria'bres.These
modifications provide for the use of
Monte' Carlo •srmtirations routines in. the
comparative-risk assessments. 2X1 though
these amtiyses do not.emp'toy all oT Qie
environmental parameters that aje
employed in the model used to develop
the screening concenlration.Ievgls {see
Urrit'HI.B), efforts were undertaken to
ensure -consistency in the specification
of the ranges and distributions of values
for parameters common to both models,
as well as in specifying their
mterre'laiionships:p.e,, correlations and
dependencies, are specified similarly in
both the screening back calculation
model and m thase analyses). Bnit JILB
provides a detailed description nf these
specifications.
(E) Exposed populations. Unlike the
deyeiqpmentiof-lhe.scieenjqg
concentration levels which aie based
exclusively xia.fistimates of ii«k io
potential maximally exposed
individuals, EPA is proposing in the
comparative jrisk.aaaaesmfliitfi.to
consider both MBIxiak aad Joial
popniation.Hek. .TotalrpqpulaUoBiifik is
.
number of additional«abi%'toi defend assigning
different aopiilafion iistribntions to
diffefent'hszarckmstroTwtHiiertts — does
not impede eoiwidering'total -population
risk in the-coinpaTativeTrsk - .
assessmeats. In •comparing -the risks
posed by land disposal and ItBitreatraent
alternatives, a smjle.jJopHration
distribution maylse asaigiujdto.each of
thetnanagement alternatives totp
evaluated. Since the analysis isjpelative
in nature, the assigned population -
di«tribtrtion,can lie entirely a&ftraiy, as
long as itisirsld constantior all of the
alternattvesio'be considered. The
purpose of-fliBcomparative.risk
•assessments is to evaluate 1he
differential effects resulting from
drffererrces m'mBTiature and magnitude
of releases from land disposal units and
from'treatmerrt.technolqgies or
treatment trains. Only by assigning the
same-populafion-distributionanboth
sides dfthe analysis can the
perfermance of various.management
alternativesihe evaluated in and
unbiasedTnanner.
Consistent .with. other slochas tier
modificatiDasJtD.the WETjnodal,.it8
procedures forxalculating population
risk were -modified to allow it Jo draw
upandifitributians. of .population
densitiec.atspaci^c-distances. (eadii)
from-disposaltuniis-oriiealmeiit
procea6es.,Data'Usad4o.flpecify these
"ring" distributions for populations
exposed Ma ^air wesetdcawn &om £PA's
Graphic Exposure Modeling System
( GEMS).. GEMS uaesrcuBent. U.S. Census
data in calculating the populaticB
density, -witfaia a ^specified radius,
arnund^aagr locatioaiinthe-Unitad
States, based>apeamat the WET
madeJ.employs;* ''severity factor" to
weight jdlSesenfSjipeB.of toxiceffeots in
estimating population risk, or numbers
of additional cases where toxic effects
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Federal Register /..Vpt 51. No. 9 / Tuesday, January 14, 1986 / Proposed Rules
compare the risks, posed by land
disposal to those posed by management
of wastes in treatment alternatives. The
analyses will also calculate various
estimates of non-human environmental
risk associated with land disposal and
alternative treatment processes.
b. Selection of models. To conduct
these analyses in the timeframes
required by the statute, EPA's RCRA
Risk-Cost Analysis (WET) Model was
selected as the analytical tool for the
comparative risk assessments. During
the last several years, EPA has
developed this model to consider the
interactions between wastes,.
environments, and technologies, and the
effects of these interactions on risks
(and costs). The model is structured to
compare hazardous waste management
practices. Because of this, the model
already contains the major components
required for these comparative risk
analyses. The Agency recognized,
however, that it would be necessary to
upgrade many of these components in
the context of this particular application.
The Agency considered alternative
existing tools to conduct the
comparative risk analyses. Other
existing multimedia risk models
designed to evaluate hazardous waste
management, however, do not consider
alternative treatment technologies.
These other models included the Liner
Location Risk-Cost Analysis Model and
the health-based back calculation model
used in setting health-based-thresholds.
EPA considered developing entirely
new models, but rejected that option
because of time limitations. Also, the
Agency desired to draw on the risk
assessment capability it has developed
during the last several years.
c.Discussion of methodology. To
design the comparative risk analyses
and evaluate alternative tools, the
Agency reviewed the WET model in the
context of the land disposal restrictions
application (a complete description of
the WET model is- available as a
Background Document in the RCRA
docket (Ref. 118). The framework of the
model is very well suited to these
analyses. The model's equations
evaluate releases and exposures at an
appropriate level of detail, considering
the generic nature of the analyses. That
is, the equations capture important
differences in releases and exposures,
yet do not require unreasonably detailed
input data.
The model evaluates a myriad of
waste, technology, and environment
combinations. The model's data bases
include 267 wastestreams, 22 treatment
and disposal technologies, and 12
environments. To calculate human
health risks, the model estimates
releases of wastes from technologies*
fate and transport of toxic constituents
through the environment, exposures to
these constituents, and health and
environmental effects from these
exposures. The model uses point
estimates to characterize typical
conditions, including waste composition,
release rates, environmental
parameters, exposure patterns, and
constituent toxicity.
A number of modifications were,
however, deemed necessary to suit the
particular requirements of these
comparative risk analyses. A number of
potential changes were considered, and
those that were most important and
feasible were adopted for the initial
analyses, the results of which are
presented in today's proposal. Major
modifications to the WET model
include:
i. Waste stream data were updated
and a broad range of representative
waste streams will be specified.
ii. Constituent data are being
expanded and updated.
iii. Characterizations of treatment and
disposal technologies were expanded
and revised to reflect the specific
management trains targeted for
analysis.
iv. The model's procedures for
specifying values for the environmental
parameters were modified to allow the
the model to function stochastically,
providing for the use of Monte Carlo
simulation routines in the comparative
analyses.
v. Data describing population
(exposure) patterns around RCRA
disposal and treatment facilities were
expanded to provide information on the
ranges and distributions of population
sizes across different exposure
distances.
vi. The model's output presentation
procedures were modified in
conjunction with incorporation of the
stochastic features and Monte Carlo
simulation routines.
The specific modifications adopted in
each of these areas are described in
greater detail below and in the
Background Document to the
Comparative Risk Assessments (Ref. 1J.
(A) Waste stream specifications. The
first step in using the comparative
analyses involves specifying the
characteristics of waste streams to be
analyzed. Since waste streams vary
considerably across processes and over
time, within the same process,
representative waste streams must be
specified in conducting generic
comparative risk assessments. In the
next few months, EPA will modify the
specification procedures to employ
Monte Carlo simulation techniques in
specifying representative waste strea,
for each waste group of concern. For]
initial comparative analyses, howeve
representative waste streams had to
specified manually. Representative
streams were therefore specified for 1
first two groups of waste subject to
today's proposed rulemaking: (1) Solv
wastes (F001 through F005 and
associated U and P wastes); and (2)
wastes containing-dioxins.
In general, the waste streams mode,
must represent as much as possible tH
variability found in three key waste
characteristics: type of constituent,
concentration of constituent, and
physical form. In addition to their
influence on risk, these characteristic.
also influence the type of treatment th
is required for a specific waste, hi
addition to these major characteristic!
other waste characteristics conside
include- chemical and physical ,
characteristics such as biodegradatior
rate, pH, heating value, and solids
content.
Primary constituents represented bj.
the waste streams analyzed in the firs|
sets of comparative risk assessments
included halogenated solvents,
nonhalogenated solvents, and TCDD
(dioxin). In addition, secondary
constituents that may also be contains
in wastes were also modeled. For 1
example, solvent waste streams were
modeled with and without the presenq
of metals that may also be contained if
such waste streams. The presence of
metals may significantly affect the
nature and degree of releases from
treatment and disposal process, as we|
as the risks corresponding to those
releases. Similarly, waste streams wer
specified with high and low
concentrations of key constituents, i
in various physical forms (e.g., as solic.
sludges, and liquids). The representati^
waste streams actually specified for th
solvent and dioxin comparative risk
assessments are described in detail in |
Units V and VI. Similar efforts to spec
representative waste streams will be
undertaken in future comparative
analyses, particularly after the model i|
modified to specify waste stream
characteristics stochastically.
(B) Constituent data. In conjunction
with development of the health-based
concentration level, EPA is developing I
additional and updated information on]
the chemical and physical properties ol
hazardous constituents. This
information includes data on toxicity,
mobility, persistence, and
bioconcentration. These new data are
incorporated into the model's
eonstituent database as they become
available.
-------
r /
ami,
In this situation. ERA-ffiuat-deteraine
the approp^ate-ievel-efjaskiairoidance
to incorporate-rate the aMailabiliJy
decision for incineration. Ja-thersame
example, if, in .the IQfexcent ot the
outcomes where incineration is
indicated to.be more riskyithan land
disposal, the consequences associated
with these risks are-many orders of
magnitude greater than those associated
with landidiaposaLiihe Agency might
prefer to designate the treatment
alternative "unavailable" so.as to avoid
setting BDAT'based on this technology
and,.in turn, avoid'the risks of-these
catastrophic cansequences.-Coavefsely,
if the consequencee-of these more risky
outcomes a*e-only-sightly worse than
those associated with land disposal, an
"available" des^naiionicff incineration
might.be njoie.ajjpKipriHte.ln this case,
the Agency ..would be «hoo«inita incur
the psiftsibiU^iof minor, infeequent.risk
increflBesin^rder-tB,take advantage of
thejisk:reductianimclicatadtobe
provided byiheftaahnolagjr in.the-vast
majority of ithe vtaste jnauagement
scenarios-
Initially, tBfiA JUMMtigfltedttiiB
application of a rigonms-titatiBtical
gaiB«tay. J«uaiy M. HflBB / Jfrqpraed flafa
the scenanoe-outlined^beve.-lninis
framework, hypothesis -tests were
considarfidf0r«valuating£tatiaticaily
significant tiiffeeences in. theia^n
values irf the «sk distrifoutians.
Differences in:the*ariaaae of the land
dispasal^and aJtemativB-trealmBni risk
distributions Htese anvestigaieilas
indicators of KenanMtwhere ihe-riak of
one altarnatiwe-isii^iefatiwe-to that of
there therdnal iea»t u>me tffihe
outcamefl.. Baaed en*te6s&ca%
significant difie«eaces in mBBas and
variances of ,tiie:riak.iHs*ributians
was consktesd&ir assessing the
availability of alternative treatumnt
technologies.
pat
itaiiBtinaltteato-inaasuie
difference* inicentad teadenta
Measures of central tendencies,
ohBerveri/hie^o the nccanenne of
"outliner'\aitu«tioa83n wmch:risks are
eHtimatediD fa&substanJial,.although
hi^r JafrHquenL, After revfevnng the
pjEDGedmes that.piedict these outliers,.
Ae Agency Mgerijihai they'represent
possibilities tfaatshoiddnatbe
discounted, fiennni significant
uacertamryjabDot tfae;nB5anti& is not
captured JHrrhevaBanae'0f the risk
J*_i._''l_ j^ ____.i*i i . * * • ^
considerfldimrlhe-raodfil jnoh^s
uncertaittty sons anitaiBkaeatimgtea for
adverse tojHcIiealtn effects, coatiibirte
-tP-t}g model
result Ie*lsjaf3he.aiaii3iscal
significance of^fferenBeB in -means and
measure* iwarianae^vfluhi mxtxaptere
these adj£lin»l uncHStaiirties.
the relative ackfl^ iarai di»|M»al ami
siraightfan9«nL-&Bii anaijrses ase
ges,;
uie 13:
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Federal Register / Vol. 51. No. 9-/ Tuesday, January 14, 1986 / Proposed Rules
are expected to be realized. The severity
factor assigns equal weight, or severity,
to all forms of carcinogenic effects (e.g.,
cases of skin cancer are counted equally
with cases of colon cancer). However,
the severity factor discounts, or assigns
weights of less than 1, to other forms of
toxic effects, such as neurotoxic effects
(e.g., if 10 cases of neurotoxic effects are
anticipated, the model adds only 5 cases
to the total number of estimated
additional cases where toxic effects are
expected to be realized). This
discounting is employed as a mechanism
to reflect the judgment that carcinogenic
effects are more severe than'
noncarcinogenic effects. Reasons
supporting this judgment include
properties such as reversibility and the
likelihood of avoiding fatalities. EPA is
concerned, however, that use of the
severity factor may in some cases bias
the evaluation of the performance of
land disposal and treatment
alternatives. These concerns are
reflected in the procedures and criteria
proposed by the Agency to evaluate the
results of the comparative analyses, as
described later in this. unit. Nonetheless,
EPA specifically requests comment on
whether it is appropriate to employ a
severity factor. A complete explanation
of the severity factor is provided in the
Background Document on the
Comparative Risk Assessments (Ref. 1).
(F) Environmental risks. The
restrictions program may or may not
decrease environmental risks, that is,
harm to plants and animals. Because the
program, in general, shifts hazardous
constituents from ground water to the
other media, there exists the potential
for increased environmental risks.
EPA is now evaluating the potential
for environmental harm in land disposal
and alternative treatment processes,
particularly that resulting from surface
water releases. Land disposal
technologies may release wastes to
ground waters that subsequently
inercept surface waters. Treatment
technologies may release constituents to
.surface waters from spills and routine
effluents.
EPA is developing a methodology (as
part of the WET model) to evaluate
environmental damages in surface
water, using a damage function, or
scoring system. This damage function is
essentially a dose response curve to
measure the severity of damage to an
ecosystem. The lowest score is
associated with an appearance of
contaminants in surface water at the
lowest concentration believed to result
in toxic effects to the most sensitive
aquatic species (i.e.. the lowest score is
associated with the threshold at which
toxic effects begin to be to realized in
the ecosystem). Scores increase as
surface water contaminant
concentrations increase, with the
highest score for ecosystem damage
associated with the surface water
contaminant concentration believed to
result in catastrophic damage to the
ecosystem. Catastrophic damage is
defined as the contaminant
concentration believed to result in
actual breakdown of the ecosystem due,
for instance* to the loss of species whose
presence is-critical to the system's '
continued operation, or survival. Based
upon several case studies on the effects
of hazardous- constituents, EPA
estimates that the surface water
contaminant concentration resulting in
catastrophic ecosystem damage is
approximately 2.5 orders of magnitude
greater than the lowest concentration
believed to result in the occurrence of
toxic effects in the most sensitive
species.
At present, the results of these
analyses of environmental effects are
being developed. The first measure is
based upon the most severe ecosystem
damage predicted to occur (i.e., the
ecosystem damage associated with the
highest contaminant concentration
resulting from releases of hazardous
constituents to surface waters). This
first measure is analogous to MEI risk
estimates for humans.
The second measure of surface water
environmental risks being developed is
a weighted estimate of the total volume
of surface water contaminated with a
constituent at any concentration greater
than the minimum concentration
believed to result in toxic effects in the
most sensitive species. The volume of
water contaminated is weighted by the
severity of effect on the ecosystem, as
indicated by the damage function
described above. This second indicator
is somewhat analogous to estimates of
human population risk, and will be used
by EPA accordingly.
(G) Monte Carlo simulation routines/
output presentation. In order to evaluate
explicitly the effects of the
environmental and population
distributions on risks, distributions of
risk estimates are produced for each
waste and technology combination over
the course of 2,000 iterations, or WET
model' runs. Under the Monte Carlo
simulation routine, the model selects
values at random from each
environmental and population
parameter distribution for each
iteration. This methodology generated
distributions of population, maximum
exposed individual, and environmental
risks, in total and by media, for each
waste and technology combination. All
calculated are means, standard
deviations, and other statistics -
describing these output distributions.
The results of these runs are then
formatted into risk matrices, broken ou|
by constituent and environmental
media. In addition, these output
distributions are plotted as relative and
cumulative frequency distributions to
allow for visual inspection and
comparison.
3. Decision-Making Criteria
The distributions of risk estimates
corresponding to management of each
representative waste stream in each
assigned treatment technology or
treatment train will be compared with
the risk distribution developed for direc|
land disposal of this waste (i.e., the
baseline). The purpose,of this
comparison is to identify treatment .
technologies or trains that, when appliej
to a specific waste stream, pose risks
greater than those posed by
management of the waste in land
disposal units. Those treatment .
technologies or trains that are
determined to be riskier than land
disposal will be considered
"unavailable" for purposes of
establishing the treatment standard, as
outlined in Unit II, and in addition will
be the subject of additional regulation oj
prohibition, as described in Unit III.C.4.
In evaluating the relative risks of land
disposal and the potential treatment
alternatives, four general outcomes are
anticipated:
a. The treatment alternative is always!
less risky than land disposal. I
b. The treatment alternative is always]
more risky than land disposal.
c. The treatment alternative has lower
average risks, but is still more risky thar
land disposal under certain conditions;
d. The treatment alternative has
higher average risks than land disposal, |
but is less risky than land disposal
under certain conditions.
In cases a and b, the availability
decision is relatively straightforward;
less risky treatments would generally be|
considered "available" and more risky
treatments considered "unavailable."
Cases c and d, however, pose more
difficult problems because EPA must
evaluate the "tradeoffs": higher or lower|
average risks versus the likelihood that
there will be some outcomes in which
average risks are poor indicators of the
actual relative risks. For example,
analysis might indicate that incineration |
of a waste has lower risks on average
than land disposal, but in 10 percent of
the outcomes the incinerator risks are
much higher than those of land disposal.
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Federal Register / Vol. 51, No, 9 / Tuesday. January 14. 1986 / Proposed Rules
In the first stage, land disposal and
treatment risk estimates (distributions)
generated by the analyses are plotted to
produce "risk profiles." Separate
profiles are produced for MEI risk,
i Copulation risk, and (other-than-human)
environmental risk. The plotted risk
profiles organize the risk estimates in
each of these categories (generated
using the Monte Carlo simulation
Figure 14
routines over the course of 2,000 model
runs) from highest to lowest, forming a
cumulative frequency distribution curve
as illustrated in the following Figure 14
(using log of risk versus percentile):
Population Risk Distribution / W.S. 21
J9
ac
I
100
Figure 14 presents a hypothetical plot
of the risk profiles for the-treatment
alternative (crossed line) and for land
disposal (boxed line). The "\"
coordinate of each "x" 'V pairon;the
curve indicates the percentage of the '
outcomes in which the risk exceeds each
value indicated by the "y" coordinate.
(Note that the actual values on the "y"
axis are an arbitrary scale; in the
comparative risk analyses, absolute risk
scores are unimportant and the
evaluation focuses on the differences, or
relationships between the treatment and
land disposal risk distributions.) As can
be seen in this example; land disposal
population risks exceed treatment risks
in nearly 50 percent of the observations*
but in the remaining 50 percent of the
expected outcomes treatment risks are
greater than those posed by land
disposal.
The purpose of the first stage of the
analysis is to identify treatment
technologies that are always less risky
than land disposal. In the context of the
risk profiles, treatment alternatives are
considered always less risky than land
disposal when all points on the
treatment's risk profile curve are inside
(below) the risk profile curve for land
disposal, as illustrated in the following
Figure 15:
-------
OECtSION TBE£ FOR COMPARATIVE RISK ANALYSIS
ftch vMtt tir«i«. »4oi mi counm •
ktitlln* «n< lh« tt««im«ni jlwin«
M Oe«t ihe iitiimeni cuivt «v«r ovirl** i
U An ovttU* eih«i ih«o lo* pto»*»iliiv ««* "'I11
-------
A-VoL 51> No. g / Tueaday, January 14. 1986 / Proposed Rates
Cases where treatment risks are
dominated by a constituent or
environmental media different from
those observed for land disposal risks
are automatically designated for further
analyses in order to consider the effects
ol uncertainties not considered in the
Monte Carlo simulation routines. Areas
of uncertainty not addressed through the
Monte Carlo process include those
associated with the specific algorithms
and assumptions used to model
transport through specific media,
uncertainties about technology
characteristics and associated
performance, and uncertainties about
th& physical and chemical properties of
hazardous wastes, their constituents,
and the nature and magnitude of their
toxic effects. These uncertainties,
referred to as "differential"
uncertainties, are particularly important
in the cases identified above because .
they may result in non-parallel shifts in
the risk profile curves, causing curves to
overlap even where the quantitative
results indicate that they do not.
Accordingly, observations of cross-
media risks and cross-constituent risks
will be used as indicators of potential
differential uncertainty impacts. Before
determining that treatment technologies
are available in these cases, the
potential impacts of differential
uncertainties will be evaluated. In
situations, for example where treatment
risks occur via air while land disposal
risks occur via ground water, the WET
model's fate and transport equations
will be evaluated for their handling of
the specific wastes and technologies
involved to determine if any systematic
biasing of the results is occurring. While
attempts have been made to eliminate
such biases from the WET model, it is
difficult to ensure that air modeling is
equally as conservative as ground water
modeling. When treatment and land
disposal risks occur via the same media,
concerns about biased results do not
arise, since the model evaluates each
technology identically. Evaluations of
differential uncertainties will involve
more indepth examination of the WET
model's algorithms and assumptions,
and may include the use of other fate
and transport models to determine the
potential effects of these uncertainties.
If these evaluations indicate that
differential uncertainties are not likely
to change the conclusions drawn from
the original risk profile curves, treatment
alternatives will be determined to be
"available" for purposes of establishing
section 3004(m) treatment standards. If,
however, these evaluations indicate the
possibility that the risk profile curves
could shift significantly enough to result
in substantial overlap, these cases will
be the subject of further detailed
analyses, as in cases where the risk
profile curves indicate substantial
overlap. The nature of these detailed
analyses are described below.
In cases where the risk profile curves
cross (as in Figure 14) or where analyses
of differential uncertainties indicate that
the curves might cross, EPA will attempt
to quantify the nature and extent of the
overlap (or potential) overlap.
Specifically, how frequently are
treatment risks likely to be greater than
those posed by land disposal? When
treatment risks are greater, how much
greater are they? Do the greater
treatment risks occur at the low end or
the high end of the risk spectrum?
Depending on the answers to these and
other questions, treatment technologies
whose risk profile curves indicate that
they may in some instances pose greater
risks than land disposal may
nonetheless be designated as
"available" for purposes of establishing
the section 3004(m) treatment standards.
For example, consider the case
illustrated in the following Figure 18
where MEI risks from treatment are
greater than land disposal in less than
one percent of the observations:
-------
£wtant
/ *»L 31, J**.*./ Ictaiay,
MB& /
figure l*j
Population Risk Distribution > W.S. 22
ac.
JS
1
0
! 1
20
i i i
. 40
i i
60
50 .
i 1
1C
r—Cumuletfv* Fr«ju«ney
ConrXLF + Ine
In this scenario, the probability that
risks exceed the value on the "y" axis is
always greater for the land disposal
technology.
For a treatment process or treatment
train to be identified as always less
risky than land disposal in the first stage
of the analysis, land disposal must
always be riskier than the alternative
treatment in each of the MEL
population, and environmental risk
profiles. If the treatment alternative is
more risky than land disposal in any of
these risk metrics, the case is designated
for further study in subsequent stages of
the analysis. Thus, detailed analyses 'are
performed for Cases b 'through d
discussed above.
As an initial screening procedure, the
risk profile comparison is conservative
in identifying technologies that are
likely to be designated as "available"
for purposes of establishing section
3004(m) treatment standards, since a
treatment alternative's risks must
always be lower than those for land
disposal. However, because uncertainty
does exist around the precise values
plotted in the risk profile curves, it is
possible that a treatment alternative
that appears to be always less risky
than land disposal could, in fact, be
more risky than land disposal at some or
even all points along the curve. While
recognizing this possibility, the Agency
believes that where this type of
uncertainty exists, the statutory
presumption against land disposal
generally suggests the alternative should
be designated "available." Specifically, ,
in such cases the comparative risk
assessments will not have provided
evidence that the treatment alternatives
pose risks that are significantly greater
than those pos*ed by land disposal—
evidence that is required under EPA's
proposed decision-making framework in
order to determine that a treatment
alternative is "unavailable" for use as a
basis for a BDAT treatment standard.
Nonetheless, two overrides to
immediate "availability" designations
based on the risk profile analyses have
been incorporated into the proposed
relative risk evaluation methodology in
order to address concerns over key
areas of uncertainty in the analytic
results. Cases will be automatically
designated for more detailed evaluation
in subsequent stages of the analysis,
regardless of the nature of their risk
profiles, where:
•i. The .primary medium by which the .
risks occur is different for land disposal
than for treatment alternatives;'and/or,
ii. The constituent responsible for
most of the risk is different for land
disposal than for treatment alternatives.
-------
review available literature and examine
actual operation of-land disposal and
treatment alternatives in the
management of specific hazardous
wastes at "representative" RCRA
facilities, and will utilize more
sophisticated modeling techniques than
those employed in generic WET model
analyses. The purpose of these case
studies is twofold: to make a final
determination as to whether a treatment
technology should be considered
"available" or "unavailable" for
purposes of establishing section 3004(m)
' treatment standards; and, if the
technology is determined "unavailable,"
to provide sufficient data to support
additional regulation of the technolo°v
by EPA (see Unit ffl.C.4). The Agency
does not expect many treatment
technologies to require these indepth
case studies hi order to determine their
availability" for purposes of
establishing section 3004{m) treatment
standards for specific hazardous wastes.
To the extent that more technologies
require such case studies than are
anticipated, other factors such as the
volume of the waste currently being
land disposed will be used to establish
priorities to indicate which treatment
alternatives will first be the subject of
these analyses.
4. Additional Regulation of Treatment
Technologies
Where the results of the detailed
evaluations described in the previous
unit conclude that a treatment
technology or train should be designated
as "unavailable" for purposes of
establishing treatment standards for one
or more specific hazardous wastes, EPA
intends to develop additional regulatory
controls for such technologies to reduce
these unacceptable risks. For example, if
the comparative risk assessments '
indicate that air stripping of volatile
solvent wastes results in unacceptable
releases of hazardous constituents to the
air, the Agency may develop regulatory
controls on the design and operation of
air stripping processes to reduce these
risks. If these additional regulatory
controls are promulgated 6y the time the
treatment standards takeeffect, the
technology may be designated as
"available" for use hi achieving the
standard (and the standard may be
revised to reflect the improved
performance of air stripping, if air
stripping represented the best
demonstrated achievable technology)
There may be situations in which
additional regulatory controls are not
possible, do not sufficiently reduce the
unacceptable risks, or cannot be
promulgated by the.time the section
3004(m).treatment standards take effect.
/,.VeL 51.NP. a / .Tuesday, January 14. 1986 /
Rules
In such cases, EPA will attempt to
promulgate regulations prohibiting th<
use of riskier technologies by the
effective date of the treatment
standards.
Additional standards for treatment
technologies may be developed under
RCRA, as in the case of additional
incineration standards, or under other
statutory authorities. For instance, the
Agency could establish appropriate
standards for surface water discharges
or discharges to publicly owned
treatment works under the Clean Water
Act.
5. Results of Initial Comparative Risk
Analyses
The procedures described above were
employed hi conducting comparative
risk assessments for the solvent waste
streams and dioxin-containing waste
streams for which section 3004(m)
treatment standards are proposed today
The results of these initial analyses are
presented in conjunction with
discussion of the proposed treatment
standards for these wastes in Unit VI.
D. Application of Standards
I. Leaching Procedure
As indicated previously, when
treatment standards are expressed as an
extract concentration, the Agency is
proposing to use the recently developed
toxicity characteristic leaching
procedure (TCLP) to determine whether
applicable levels have been achieved.
The TCLP was developed for use hi
conjunction with an expanded Toxicity
Charateristic. The current Extraction
Procedure-Toxicity Charcateristic (40
CFR 261.24).entails use of the EP. a
leaching test used for identifying wastes
as hazardous based on their likelihood
to leach toxic contaminants. While the
EP was optimized for inorganic
constituents EPA's intent in developing
the TCLP is to produce an unproved
leaching test method suitable for use in
evaluating wastes containing organic
constituents, as well as inorganic
constituents. Thus the new TCLP
represents a single test procedure that
can be used to evaluate the leachability
of all toxic contaminants in a waste.
The TCLP is also an improvement
over the existing EP in several
operational aspects. For example, the EP
currently involves continual pH
adjustment (titration) with 0.5 M acetic
acid to a pH of 5.0 + 0.2. This can
involve more than 8 hours of operator
attention and can be difficult for some
waste types, particularly oily wastes. In
developing the TCLP. the need for
continual pH adjustment has been
eliminated. In addition, the EP involves
separating the initial liquid from the
solid phase of the waste, as well as
separation of the liquid (extract} derived
from the leaching test. These steps,
currently involving pressure filtration
through'a 0.45 urn filter, can be difficult
and time consuming for certain waste
types. EPA expects that these problems
will be avoided in the new procedure. In
addition, because the new procedure
has been developed to address the
leaching of organic compounds as well
as inorganics, the new procedure is
designed to prevent loss of the volatile
compounds through the use of a zero
head space extractor. Finally, other
minor problems in the EP protocoal,
such as accounting for the loss of waste
materials to the sidewalls of sample
containers, have been corrected in the
new procedure.
Athough the TCLP was developed to
model the codisposal of an industrial
waste in a municipal waste landfill, EPA
believes that the predicted degree of
contaminant migration could reasonably
occur during the course of most waste
management, including the RCRA
Subtitle C hazardous waste land
disposal situation. This applies to the
leaching of both organics and
inorganics.
Since leaching results from the
percolation of rainwater through the
land disposal area, the leaching medium
is almost always primarily aqueous in
nature. As the rainwater precolates
through the waste, it naturally picks up
contaminants from the waste. However,
the leaching medium is still primarily
aqueous./As was demonstrated by the
leaching experiments conducted during
development of the TCLP (Refs. 46 and
47), as well as other research (Ref. 22),
minor changes to primarily aqueous
media do not generally result in
significant differences in the degree of
leaching of organic compounds. For
inorganics, where the degree of leaching
is most affected by pH conditions, the
acidity afforded by the TCLP leaching
medium accounts for the possibility that
wastes could be subjected to mild acidic
conditions which could occur in RCRA
Subtitle C land disposal environments.
Of course, wastes do have the
potential to be subjected to more
aggressive leaching conditions that
might be better modeled through the use
of strong inorganic acids or perhaps
certain types of solvents. However, the
Agency finds it difficult to support the
use of these more aggressive leaching
media, primarily because it would be
difficult to support a reasonable worst-
case mismanagement scenario for use of
these media. This is particularly
significant for the RCRA Subtitle C
-------
JtogiBter f *jyL «. SBa.?.* / •Tfaaa^yl
$t.!
Fiquro Id
MEl Risk Distribution / W.S. 21
a '8—a ' a
4ft
'si
In almost. all cases, treatrnEnt msks aie
sukstanHfllTy less than those of laiui
iprmnrp, uthpn tteaJaieat
i jrppjpr tfaan Junftl *ligprnmJ rvokg techsolfig)! JAltlte
i inrrf^jip^ in riniff] in'Qcder
to take aduaniag&of. Ihe.auhaUatial xiak
i affrnnd fej I
followed by jmtenfiaJ neuatoos to the
input apecificatiojts wkece modeling
algorithms or «BiMHptkuM ace believed
to he iTypr°«fmaip forspecific
groater (eig.
mangniiu«t&), i
consequence* .
events are B»tiiieeJ|c*>-isB •gniicasitty
greater ^1<»»« riun« »«ii«fnn*»J witt land
disposal Brakflui4l»«ate«l tkattiie
WET m«tel is -paanoly a uelafiME ask
presentnd origina% ia Figue 1A. Ifeoe,
absolute, er aeduai, ri»kaiz not
devekipedin this-eaennse and, as noted
comparative aiMljcses. BPA. \t Bkely in
situations euoh as- tkoee iUi»S«ted in
Figure IB to despite treatment
ahernalives as "avaSarHe" far-purposes
of egteMfahing 1he section 309f(nr)
standards, teading-oTF the poasrbiltty of
highly infrequent, low relative
risto *»a land *sp*eal« nsariy 68-per
cent of tits «to»ensattoJW. fWlbamrore,
treabnentrfcks are onhateinftnHjr greater
than land ^dtopaonl nsk&in«na»y of
these obsenratims. EPAis net fikely to
desigBate JedntolegieB CKii^iMng these
types of risk pivfiles as **a*a8abie"
wj*hoat conducting fmrlhtu -imdep 111
analysts. Farther-stages of detailed
analysis wchide ~eirartUfCiuiiB or me
sonrces of increased risk through
examination of release estimates
provided'bjrrhe WETtffadtd (i.e., which
part of the treatment process or train is
responsible for-the increased risks?),
coaditrana. These aewsiaas ma^reaalt
in jnakyixafile curves that a» langer
craas, in wbidi ease the Agency w likelyl
to deaignatB the tuea-Jment akeraative as|
"avaHetble."
AllK3i£rtrtteiy, tbe revised risk
analyse* nwy -continue to indicate
greater risks in treatment. At this point,
EPA wiil tervfr enhatnrted the resources
of the WET model in conducting
comparative risk assessments. Before
making a dviunuhialiua that the
treatment alternative is "unavailable"
for purposes of establishing section
3004(m) treatment standards, however,
EPA will conduct an indepth case study |
to characterize fully the risks posed by
its use in the management of specific
hazardous wastes. Case studies will
-------
IMS
F«faml Be^^ ;
; ramiary 1*. l§8g / Proposed
waste is "identified" by any of the
hazardous characteristics HiEhided m
Subpart C of 4O CFR Part 381. -This
detennination may be made, by either
testing the waste or by the application
of knowledge of the waste in light of the
materials or the processes used in its
generation (40 CFR 262.11). Thus.
although generators are held responsible
tor determining whether their wastes are
hazardous, they are not specifically
required to perform testing for tut keep
records} to make this determination.
After evaluation, of these alternatives.
EPA is proposing the third option
whereby the disposer would be held
responsible for testing the wastes. The
Agency believes that this approach
would produce the desired result—an
assurance that the wastes placed in land
disposal facilities have met the
applicable standards. It is flexible, does
not require redundant testing, fits into
the current regulatory scheme for the
waste analysis plan and requires the
testing to take place where the liability
for disposal exists—*t the land disposal
facility. In addition, many disposal
facilities already will have laboratory
capabilities because of the existing "
waste analysis requirements!
To implement the proposed approach
the Agency has included a reference to
the requirements of Part 288-in the
general waste analysis requirements in
§ 264.13 (a)(l) and (b}(6). for permitted
facilities, and in S 285.13 (a)(l} and
fbj(6), for facilities in interim status.
Consistent with the current approach to
waste analysis requirements in Parts 264
and 265, the Agency also has added the
specific waste analysis requirements
resulting from the restrictions program
that must be incorporated into the
general waste analysis, as a separate
section in Part 268. Lastly, the Agency
has revised the operating record
requirements in §§ 284.73 and 285.73 to
indicate that waste analyses conducted
pursuant to this requirement be
recorded and maintained in the facility'3
operating record.
In those cases where the applicable
treatment standards are expressed as a
concentration in a waste eran extract
from a waste, the waste anafysi*
requirements being proposed in Part 268
mandate that actual testing of the waste
be conducted. (Frequency and sampling
procedures are specified in J§ 264.13
and 265.13). Where the applicable
treatment standard: for the waste is
specified as a method of treatment,
testing to determine compliance is net
applicable. In such cases, a certification
by the generator or treatment facility
owner or operator ia sufficient fa
demonstrate compliance. The Agency
requests comments on the proposed
approach, as well as the alternative
approaches discussed.
3. Facilities Operating Under an RCRA
Permit
Land disposal and all other facilities
which have been issued RCRA permits
prior to the enactment of the HSWA
must comply with certain requirements
of the HSWA even though those
requirements are not specifically
referenced in the permit conditions. The
Agency anticipates proposing in
separate rulemaking, an amendment to
§ 270.4 to indicate that facilities with
RCRA permits are subject not only to
the conditions written into the permit,
but also must comply with all applicable
requirements of the HSWA (including
implementing regulations} which wmttd
otherwise go into effect by statute.
Since the land disposal restrictions do
go into effect by statute, permitted
facilities would be required to comply
with all applicable land disposal
regulations when they become effective.
even if the regulation? are not
referenced in the permit.
In order to facilitate implementation
of the land disposal restrictions
program, EPA isr considering modifying
the RCRA permitting regulations to
' ma*e it easier for permitted treatment
facilities to accept new waste streams
not covered by their permit For
example, incinerator permits may
specifiy the waste codes and volumes of
waste which the unit is permitted to
incinerate. Alternatively, the permit may
be written to allow the incineration of
broader categories of wastes if the unit's
previous trial burn {or data in lieu of a
trial burn) demonstrates the applicable
Destruction and Removal Efficiency
(ORE) on a Principal Organic Hazardous
Constituent {POHQor compound more
difficult to incinerate than those wastes.
Presently when waste code* are
specifically Ksted in a RCRA permit, the
permit must be modified to- include any
additional waste codes handled at the
permitted unit When waste codes are
not specifically listed m. a RCRA
incinerator permit, a waste may be
incinerated at a permitted unit if it-is
less difficult to incinerate than the
POHC for which performance data ate
avaUable, and all other conditions of the
permit (e.g., minimttm heating value of
the waste) are met. If the permitted unit
had demonstrated the applicable ORE
on a POHC tesa difficult to burn or had'
not demonstrated the applicable DRE,
another trial burn is necessary, and the
permit would need to be modified.
In order to provide flexibility in
meeting the capacity demands that wilt
result from the restrictions program mas
;timely a manner as- possible, EPA is
considering allowing the treatment of
restricted wastes (except for wastes -
containing dioxins)- at permitted units
without requiring the units to add waste-
codes through the permit modification
process. This change would not allow
now treatment processes or units to be
added without a permit modification but
would provide flexibility to permitted
units to expand the types of waste they
treat. Dioxin-containing waste (F020
through F023 and F028 through F02&J
may he treated only at units which have
been certified specifically to manage
those wastes.
Another alternative is to require any
permitted treatment unit to modify its
permit before treating arty restricted
wastes not covered by its. permit These
permit modifications currently must be
processed under i 270.41 (major
modifications). Alternatively, EPA could
revise the Part 270 regulations to
simplify the modification process by
•allowing the incorporation of restricted
wastes at permitted treatment facilities
as a modification processed under the
§ 270.42. (minor modifications).
procedure. EPA invites comment on.
these possible alternatives.
E. Determination of Alternative
Capacity and Ban Effective Dates
RCRA section 3Q04(h)(2). states that
the Agency may grant a variance of up
to 2 years from the statutory ban.
effective date if adequate alternative
treatment, recovery, or disposal
capacity which protect*human health
and the environment is not available.
Congress, however, intends for the land
disposal restrictions to "go into effect
immediately upon promulgation
whenever and wherever possible-" (S.
Rep. No. 98-284, SStfeCbng., 1st sess. 19
(1983)) The legislative history also states
that "the Agency should expend every
effort to assure that unsafe practices are
terminated as quickly as possible."
Therefore, "extensions based en
capacity shortfalls should be
infrequently granted: Given consistent
regulatory and economic incentives,
adequate capacity will be quickly
developed." (S. Rep. No. 96-284, 98th
Cong.. Isf sess. T9(1983)J'The proposed
procedures for extensions appear at
§ 268.4. EPA wiH consider several
factors when calculating alternative
capacity and1 when determining the
length of any variance from- the ban
effective dates mandated by RCRA.
These factors are discussed below.
1. Ban Effective Dates
EPA will develop estimates of
treatment rapacity needed versus
-------
Federal Register I VbL Sl.-.Nbeft /' Tuesday^ January14; lJ98j| / F¥^gsed"Rules _
hazardous waste land disposal situation
since early in this program, EPA-is
restricting the disposal of solvent and
acidic wastes in RCRA Subtitle C
hazardous waste management land
disposal facilities.
In addition, it appears that small
amounts of some solvents may not
affect leaching significantly. The TCLP
was developed from a field-model
lysimeter experiment which generated a
municipal waste leachate (MWL). The
leaching media for the TCLP (acetate
buffer) was selected primarily because it
was an adequate model for the MWL.
The MWL, in addition to containing
carboxylic acids and higher molecular
weight organic compounds, also
contained toluene, a common industrial
solvent, in the range of 1 to 2 parts per
million. It also contained other common
industrial chemicals, such as benzene.
however, at lower concentrations. The
presence of these compounds in the
MWL did not appear to affect the
leaching of organic compounds to a
significant degree.
Another consideration in the Agency's
decision to propose the use of the TCLP
in the restrictions program is the time
constraints of the program. It took EPA
approximately 4 years to develop and
evaluate the TCLP. Congress, in
directing EPA to identify treatment
standards for wastes banned from land
disposal, provided strict time limits
under which regulations must be
promulgated. If EPA were to develop a
new leaching test for the land disposal
restrictions program, the congressionally
mandated timelines established for
these decisions could not be met.
The protocol for the TCLP is set forth
in Appendix I. In addition, detailed
information on the development and
evaluation of the TCLP will be
presented in the Organic Toxicity
Characteristic proposed rule, to be
published in the Federal Register in the
near future.
2. Testing and Recordkeeping
Under the framework being proposed
today, determination, of whether a waste
or treatment residue requires further
treatment prior to land disposal '
generally depends on whether the '
concentration of constituents in the
waste, or in an extract from the waste
(using the prescribed leach procedure).
exceeds the applicable regulatory ,
thresholds. Because this determination
is critical to the proposed scheme, EPA
is proposing to impose waste testing/
analysis requirements.
The Agency first considered who
should bear the responsibility for • '
testing: the generator, the owner/ .
operator of the treatment facility and/or
the owner/operator of the land disposal
facility.
The Agency considered three possible
approaches. The first option would
require that testing be conducted by the
generator, the treater, and the ultimate
disposer of the waste. The second
option would require testing at the
treatment facility and disposal facility
(when they are separate facilities). The
third option requires testing at only the
disposal facility.
In the first option, the generator would
be required to test the wastes before
sending them off-site. As a result, the
generator would know to send waste for
treatment if it exceeded the xegulatory
threshold or for disposal if the
concentration of constituents in the
waste were less than or equal to the
regulatory thresholds. The test would
include only measurement of those
constituents listed in Table CCWE of
the regulation (§ 268.42). The generator
initially would have to test the waste
and establish the concentrations for the
constituents in Table CCWE. Testing '
would be repeated when the process or .
inputs changed or the generator
expected that the constituents in the
waste stream may be different.
Following treatment, the treater would
be required to test the treated waste.
Finally, the disposal facility would have
to verify that the waste met the
treatment standards by testing the
shipment, possibly doing a modified
waste analysis of the constituents of
concern. Jf one or more processes
occurred at the same site (e.g., the
generator also treated the waste prior to
sending residues off-site for disposal, or
the generator shipped the waste off-site
to one location for both treatment and
disposal), testing would be required only
once at each location. Thus, for
example, a generator who also treats his
waste would be required to test the
waste only after treatment (i.e., before it
is sent off-site for disposal). However
the disposal site also would be required
to test the waste prior to ultimate .
disposal. If generation, treatment, and
disposal all occur at the same site,
testing would be required only once
prior to-disposal.
The Agency believes there are several
advantages to this approach. EPA
believes that generators who know what
is in their wastes will send their wastes
to the proper place—either to the
treatment facility or to the disposal
facility. The testing information from the
• generator also provides valuable
information for the treater. With the
testing data, the treater will then be able
to target the amount, method, and
characteristics of treatment necessary
for the waste in question. Requiring
treaters to test wastes before shipping
them for disposal assures accountabilitj]
since they will know whether the
applicable treatment standards have -
been met. Finally, by requiring the
disposal facilities to verify the
constituent content of the wastes befor
disposal, they can assure themselves
and the Agency that only wastes that
have met the treatment standards will
be or have been land disposed.
A second option would require testing
at the off-site treater and separate off-
site disposal facility, but not at the
generator. Under this approach, the
treater would have to test wastes or
treatment residues after treatment to
show the disposal facility that they hav
met the treatment standards. The
disposal facility would then verify, by
testing, that the wastes met the
treatment standards before land
disposal. Where the disposal facility
and treatment facility are a combined
operation, the test would take place onlj
once, before land disposal.
The third option would require test:
at the disposal site, thereby assuring
that wastes placed in the disposal units I
do not exceed the regulatory thresholds^
Under this approach, the disposal
facility must either conduct an analysis |
of the waste or obtain an analysis of the
waste from the generator or treater.
Similarly, the owner or operator of a
land disposal facility could arrange for
the generator or treatment facility to
supply all or part of the required testing |
data. However, if the generator or
treater did not supply the testing data
and the land disposal facility owner or
operator chose to accept the waste, the
owner or operator would be responsible
for conducting the required testing.
While options two and three do not
require testing by the generator, they do|
not relieve the generator of his
responsibilities under 40 CFR 262.20 to
designate a facility (on the manifest)
which is permitted to handle his waste
when he sends his waste off-site for
management. Thus, a generator must
know whether he must treat his waste
prior to disposal. However, rather than
specifically requiring the generator to
conduct testing, the Agency would allov
determination of whether wastes meet
the regulatory thresholds to be based or
either testing or knowledge of the
characteristics of the waste.
Accordingly, a generator could
determine that his waste requires
treatment based solely on his
knowledge of the waste without
conducting and-keeping records of the
test results. This'approach is directly
analogous to the generator's • ; •'
responsibility to determine whether his
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Federal BagnteE / VqL at. No. a /.Taesday. January n, iggg / Proposed
compare required capacity {capacity
demand) with available capacity
(capacity supply). Througfeea* this unit
the use of the word "waster refers, to the
individual waste group OB which the
capacity determination will be based.
Currently, the major source of data for
most waste capacity requirements is the
Office of Solid Waste's Regulatory-
Impact Analysis (OSW RIA) Mail
Survey of hazardous waste management
activities during 1981 (Ref. 116).
Information concerning dioxia waste
quantities, however, was obtained-fei a-
separate effort (Ref. 87). In most other
cases, the quantities of wastes land
disposed reported in the Survey, will be
grouped according to the descripSoa of
their characteristics also provided in the
survey responses. In addition, EPA will
consider other increases in capacity
demand generated by emergency and
remedial responses. EPA also will
include^ to the extent possible, the
impact of other final ralemakings, such
as the regulation of small quantity
generators,, that have occurred since
EPA's capacity data were collected.
Under section 3005{JXtl}(B) of RCRA,
certain treatment surface impoundments
are exempted from the land disposal
restrictions. Waste currently placed in
exempted surface impoundments does
not require alternative capacity.
Therefore, the Agency is not including
the quantity of waste placed in these
units annually in its calculation of
capacity requirements. Treatment
residuals that under section
300S(j)(nj{B) must be removed from
exempted surface impoundments do
require alternative capacity and will be
considered in the analysis.
EPA may set different ban effective
dates for different waste groups
depending upon the capacity available
to handle each waste group. It will be
possible, for example, to have one
effective date for sludges that require
incineration and another effective date
for recoverable liquid* wJftm the same
waste code based on tfce availability of
incinerator and recovery praeesset,
respectively. This approach, inconsistent
with congressional intent that
prohibitions become effective
immediately whenever possible.
In some cases, the same technology
will apply to several waste groups that
must be regulated in the same
rulemaking. For instance, incineration is
the applicable technology for both
sludges, and solids feat contain high
concentrations of solvents (£&, organic
sludges and solids) and sludges and
solids that contain lower levels of
solvents (i.e, inorganic sludges and
solids). However, total capacity for
inciseraters may he insufficient to treat
both of ;thes£,groups of wastes.
One option is to extend the ban
effective date for bath organic shidges
and solids that requke incineration and
inorganic sludges and solids that
contain lesser solvent concentrations
and that require this incineration.
However, available incinerator capacity
would not be utilized under this,
approach, since all of these wastes
could continue to be land disposed
during a variance- This approach maybe
viewed as inconsistent with, the intent of
Congress: ta ban wastes as soon as-
possible.
The Agency believes that a better
approach is to subdivide the waste-
groups and utilize all available
treatment capacity on specific
subgroups in order to implement beats *s
quickly as possible. Under this
approach, as much waste as passible
would be banned immediately. One
option under consideration is to
prioritize the wastes to be banned: by,
considering: reiative toxicity, as-
represented by concentration. ThaR in
the example given above, the ban on
land disposal of organic sludges, and
solids containing solvents would be
effective immediately and a variance
granted for inorganic sludges and solids
containing solvent*. EPA solicits
comment on this method of prioritizing
treatment capacity among different
hazardous wastes.
5. Definition of Available Capacity
The Agency will consider, both, current
on-line facilities and planned facilities:
that will be completed by the ban
effective datfe as available capacity.
On-line facilities are facilities that have
pertinent wastes trader torrent
regulation* by applicable Federal State.
and local agencies; Facilities operating
under RCRA interim status meet these
criteria, and therefore wili be include*
in the capacity deternaHatioa. Curreat -
facilities are facilities; that are cm-line at
the time of the capacity aaaiysia These.
facilities include both off-site and on-
site facilities, as well as stationary and
mobile facilities. Planned facilitiea ase
facilities, that are projected,, under
development, or under construction
Planned facilities inemde bofe new
commercial and cm-site treatment.
recovery, or disposal facilities.. They
also indude planned capacity additions
or expansions ta current facilities.
undertakes by the owner/operator to.
accommodate increased demands; or
because the existing process is: used to
its total capacity;.
The planned facility or capacity
expansion wiH. be considered available
. if it is EPA's judgment that, by the time
the ban goes ints-effect,, the capacity
will be on-line, fa order to predict if the
capacity wili be on-line in tune. EPA "
will consider the time the facility will
require to be completed, including
reasonable estimates of time to site., (o
obtain permits, to construct, and to test.
In most cases, EPA will consider the
capacity of planned facilities only if al}'
permits required for construction'have .
been approved and if there is sufficient
additional evidence of intent to build,
such a* contracts issued for
construction.
As explained in-Unit III.E.4, EPA wilf
account for treatment surface
impoundments exempted from the land
disposal restrictions under RCRA
section 3«>5f JXIIRB) by not including in
the calculation of capacity demand,
wastes currently placed in such- units.
Because it has no mfonnaHon to the
contrary, EPA is assuming that alt
exempted surface impoundments that
are currently on-line are used to
capacity. Thus, for the purpose of this
proposal these units wiH not be
considered available,, unused capacity.
Any new or planned treatment surface
impoundments win be considered-
alternative treatment capacity if they
will he on-line by the pertinent ban
effective date, and if they will meet. 'Jw>
requirements of RCRA section
3005{j)(llMBJ.
6. Definition of Alternative Treatment
Capacity •
RCRA section 3GQ4(h}(2) states that a
variance from, the effective date of a
land disposal ban, "shall be established
on the basis of the earliest date on
which adequate alternative treatment
recovery, or disposal capacity which.
protects human health and the
environment will be available."
Available treatment technologies (i.e.,
those found ta present less risks thaw
land disposal} that can achieve the
screening concentration levels
established by EPA are. by definition,
protective of human health and the
environment. Such treatment
technologies will be considered in
determining whether adequate
alternative treatment capacity exists, h
the capacity of these protective
treatment technologies, coupled with
protective disposal and recovery
capacity, is insufficient to accommodate
the banned waste, EPA will exercise its
discretionary authority net to extend the
effective date if &e capacity of the
protective technologies, together with
the capacity of technologies that meet
technology-based section 3004(nj)
standards, is adequate to address the
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Federal Register / VoL'51, No. 9 ./. Tuesdayf January 14. 1986 / Proposed; Rules
capacity available to determine if
current capacity of alternative
treatment, recovery, and disposal
technologies is sufficient to manage
restricted wastes. These estimates will
be developed from currently available
data on'capacity requirements and
technology capacity. EPA also will use
interpretations of existing data if EPA
determines that existing capacity data
are insufficient. If capacity is available.
the ban will go into effect immediately.
If capacity is not available, then the
Agency will have to determine when
additional, or new capacity, will become
available, so that the length of a
variance can be established.
Establishment of the ban effective date
will not be affected by the processing of
petitions under RCRA section 3004 (d).
(e), and (g). The1 interaction between the
variance to the ban effective date and
the case-by-case extension under
section 3004(h)(3) is "discussed later in
this unit.
2. Regional and National Capacity
The Agency will make a national
determination of both the quantity of
banned waste generated and the
capacity of alternative treatment.
recovery, and disposal technologies. If
national capacity is insufficient to treat
all of the banned waste, in most cases
the Agency will extend the effective
date of the ban. If national capacity is
sufficient, the ban will become effective
immediately, even if, for instance, the
only capacity for a waste generated in
California, is located in Ohio.
This approach is consistent with
congressional intent. The Senate
legislative history provides that "the
available capacity determination is to
be done on a. national basis." (S. Rep.
No. 98-284, 98th Cong., 1st sess. 19
(1983)) That is, the effective date of the
ban for a given waste should not vary
from region to region because one region
has sufficient alternative capacity and
another does not. If cheaper" land
disposal is banned in only a portion of
the country, it is likely that waste will
be transported outside of that region
and land disposed elsewhere. This
would have the effect of discouraging
the use of treatment in those regions in
which it is available and land disposal
is banned. As the Senate history points
out, those regions of the country in
\vhich land disposal is permitted might
become the "dumping ground" for
wastes generated in regions where land
disposal is banned. (S. Rep. No. 98-284.
98lh Cong.. 1st sess. 19 (1983).)
The legislative history recognizes that
the nationwide approach to capacity
determinations "might necessitate the
transportation of wastes to treatment
facilities over significant distances." but
notes that "this kind of waste
transportation is occurring today." It
predicts the development of
"inexpensive 'milk run' style collection
services ... to meet regional demands."
S. Rep. No. 98-284, 98th Cong., 1st sess.
19 (1983)). In light of this legislative
history, EPA believes that the need to
transport wastes should not be the basis
for extending the effective dates of the
ban.
The Agency recognizes that there are
some disadvantages to making a
nationwide determination of capacity.
Even though capacity may exist in some
regions of the country, if nationwide
capacity is insufficient, all of the wastes
subject to the restrictions could continue
to be land disposed. Thus, existing
treatment capacity may not be utilized.
Industries located in regions where
treatment is not readily available may
incur higher transportation costs when
capacity exists elsewhere. The Agency
solicits comment on alternative
approaches to determining capacity
consistent with congressional intent.
3. The Nationwide Variance and the
Case-by-Case Extension
In cases where EPA has not granted a
nationwide variance, it is not precluded
from granting case-by-case effective
date extensions. For instance, if
alternative capacity exists to manage
most of the waste to be banned, the
Agency might choose not to grant a
nationwide variance, even though
alternative capacity appears to be
lacking slightly. In these cases, it is more
desirable to grant case-by-case
extensions (as described in Unit III.F) to
specific applicants who lack alternative
capacity man to allow everyone, even
those for whom alternatives are
available, to continue to land dispose of
their wastes. This approach is consistent
with congressional intent to ban land
disposal at the earliest possible time. In
these circumstances, the Agency will
specify in the proposed rulemaking that
the ban will be effective immediately
upon promulgation and the basis for this
determination. Generators,who cannot
find alternative capacity for their wastes
can apply for case-by-case extensions.
For the same reasons, EPA may grant
a variance of less than 2 years, even
though some facilities may require more
time to be completed. These facilities
could be completed under a case-by-
case extension, if all applicable criteria
are met. without allowing continued
land disposal nationwide.
It is possible that some generators
may produce wastes in such small
quantities that no commercial treatment
or other waste management facility is
willing to accept this waste. Unique
wastes may also exist that cannot be
treated by the technologies or to the
levels achievable for most other wastes.
For these reasons, a case-by-case
extension may be granted to allow
facilities generating such wastes to
provide alternative capacity or develop
appropriate treatment methods.
If the Agency proposes an immediate
ban effective date, it may receive
applications for case-by-case extensions |
before the final rule is promulgated (see
Unit III). Before promulgation of the final|
ban effective date, EPA will consider
information provided by case-by-case
extension applications as well as other
comments submitted during the public
comment'period. As a result of this
information, EPA may choose to grant a
nationwide variance in the final rule.
However, after EPA promulgates a
nationwide ban effective date, this date
is, as a practical matter, unlikely to be
amended based on applications for or
issuances of case-by-case extensions, or |
any other information available that
may indicate that nationwide capacity is|
insufficient. The Agency considered the
possibility of changing the decision not
to grant a nationwide variance if, after
the ban became effective, it received
evidence that capacity was not
adequate. EPA also considered whether
it should shorten a variance based on
new information showing that
nationwide capacity is adequate. The
Agency believes that any change to the
ban effective date would require a
lengthy rulemaking that could not be
completed in significantly less than 2
years. Since the maximum variance
allowed by the statute is 2 years after
the statutory effective date, a change to
the ban effective date probably would
not be practical.
4. Determination of Capacity
Requirements by Waste Treatability
Group
In general, EPA will develop
treatment standards for waste groups
derived from the physical/chemical
characteristcs of the banned wastes (see|
Unit III.B). EPA will also determine the
quantities of wastes that require specificl
treatment or recovery methods by waste|
treatability group. For instance, to
remove dilute solvents from aqueous
wastes, treatment processes such as air
and steam stripping are required.
However, solvent-contaminated sludges |
require incineration. Concentrated
solvent liquids may be-either recovered
(e.g., by distillation or solvent
extraction), reused (e.g., as a fuel
substitute), or incinerated. These
treatability groups will enable EPA to
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Federal Register / Vol. •». NQ. 9 / Tuesday. January 14. 1986 / Proposed Rules
capacity currently exists, or if the
necessary additional capacity can be
developed by the time the mandated
™^,J.OTeach waste
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Fedacal Bagirter / Vol. SI, Ha. 9- f Taeaday. January 14.. M8B, / Ptujteaed
restricted wastes. AstdlscussedanOnit
III. B. EPA believes that this approach is
fully consistent with congressional
intent
Treatment methods that are net
identified as BDAT for the waste group
being considered also will be included
in the capacity determination, as fang as
EPA judges that the method can achieve
the treatment standards for some of the
wastes in question and will pose less
risk than land disposal These methods
are still available to treat such
hazardous waste. EPA believes that this
approach is consistent with the
congressional intent to ban hazardous
wastes from land disposal at the earliest-
possible date, as discussed earlier.
7. Definition of Alternative Recovery
and Disposal Capacity
In general, the Agency wiH consider
the capacity of all on-line recovery and
disposal facilities that are protective of
human health and the environment in
assessing available capacity. Planned
facilities, including expansion of
existing facilities, also will be
considered where appropriate. On-line
facilities are defined asthose facilities
that have received approval from
applicable State, local, and Federal
agencies to operate a recovery or
disposal facility for the waste in
question or for a similar waste.
However, alternative land disposal
methods (e.g., deep well injection) will
not be considered as available capacity
for banned waste unless EPA has
determined that such methods of
disposal are protective for the waste in
question. This question wHl arise
frequently in the context of assessing
underground injection as alternative
capacity. RCRA section 3004ff) allows
the Agency until August 1988 to stady
the disposal by deep weM injecfiontrf
solvents, dioxins, and California Lift
wastes and to promulgate any necessary
regulations banning-these wastes from
deep well injection. This-deadline
occurs after the mandated deadlines for
ban decisions eoawieSng disposal of
these wastes by other landdisposai
methods. For X*a«te« scheduled for later
banning, the Agency will-make
decisions to ban from deep well
injection concurrently with decisions to
ban from other land disposal methods.
Accordingly, in evaluating the capacity
of alternative protective disposal
methods for these wastes prior to a
decsion under section 3004ff). EPA will
not consider underground injection to be
available disposal capacity, or since the
Agency will not have determined'
whether the injection of such wastes is
protective.
EPA is considering recydiagsinethods
in the comparative risk assessment (see
Unit III.C), and recycling methods that
EPA judges are riskier titan land
disposal methods will not be considered
available capacity. Those recycling
methods not evaluated in the
comparative risk assessment, such as
use of waste as fuel, are either currently-
regulated, or wiH be regulated under
other Agency regulatory efforts. EPA
believes this will assure that these
technologies are less risky than land
disposal.
In the past, many recycling facilities
were not subject to regulation under
RCRA. Recent modifications to the 48
CFR 281.2 regulations .defining a solid
waste, published-in e converted to commercial
capacity, and will try to estimate the
volume of wastes generated by others
that private facilities are willing to
accept. In seme .cases, the Agency's
calculation of commercial capacity
already includes the surplus capacity
located at private facilities that accept
some waste commercially. EPA solicits
comment from owners of private
facilities as to whether they will accept
wastes commercially in the future and
whether they will use their current
surplus capacity to treat their own
banned wastes.
b. Planned capacity. If EPA finds that
current capacity is insufficient for a
particular waste, it will evaluate the
potential for the development of planned I
facilities and capacity by the statutory I
ban effective date. Planned capacity will!
ako-be considered in determining the
length of a variance, if necessary (see
Unit ffl.E:9). EPA wffl also consider
planned capacity of emerging treatment
technologies (as defined in Unit III.B) if
treatment standards are based on these
technologies orif these teehnologies can
be-expected to achieve health-based
levels. Planned facilities and capacity
wiH fee-considered available only if EPA
determines that, by the time the ban
goes into effect, fhe facility will (1) be
on-line, and (ZJ-meet the screening level
(or a technofegy based treatment
standard & no demonstrated technology
meets the screening level.)
9. Time to Develop Capacity and Length
of Variance
According to RCRA section 3004(h){2). |
if the Agency determines that sufficient
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Vol. 51. No. 9 ./ Tuesday, January 14. 1986 / Proposed. Rtllea
under RCRA section 30050) or managed
m any existing portion that does not
meet the new technical requirements
referenced in § 288.40). All facilities in
which he waste is managed must meet
all applicable RCRA requirements.
The applicant must also demonstrate
under | 268.4(a) (6) that sufficient
capacity will exist during the extension
to store, dispose, or otherwise manage
the waste. The Agency, having limited
resources for the review of applications,
must assure that these resources are
used to process application* where the
applicant has already arranged for
waste management during an extension.
iflis will eliminate the need to reconsult
with affected States (see Unit IH.F.5-
below) due to changes m an applicant's
. plans.
f. Certification of application. All
applicants must certify, under penalty of
law, that all of the information provided
to the Agency is accurate under
§ 268.4{b).
5. Consultation With Affected States
Based on the information provided on
management of a waste during an
extension, the Agency will notify and
consult with appropriate agencies in all
States it judges may be affected by a
specific extension. This action is
required by section 3004(h)(3) of RCRA.
6. Notice of Initial Determination
The Agency will notify the applicant
of its initial determination as to
approval or denial of the case-by-ease
extension. Initial determination of each
case-by-case extension will be
published in the Federal Register and
comment solicited on these
determinations.
7. Granting of Extension Approval
If EPA grants an extension of the ban
, „ v,e date based on a11 assessment
of all of the information provided by
applicants and by others during the
comment period, it will provide the
successful applicant with a written
notice of the extension. This notice will
describe the manufacturing processfes)
that are the source{sj of the waste
subject to the extension,, the volume of
such wastes, the disposal facilities in
which the waste will be managed during
the extension period.
Because waste identical to waste
granted an extension is otherwise
prohibited from land disposal when it is
generated by someone other than the
applicant, it is important that the site of
land disposal of the waste granted an
extension be documented. The Agency
is requiring under § 268.4(e) that the
successful applicant retain the approval
notice in his operating record during the
period of the extension and for at least 3
%years after the extension expires. In; . „
addition,' the applicant must provide a ""
copy of the notice to any land disposal
facility identified in the approval notice
before to the first shipment of waste
granted an extension is sent to the
facility.
The owner or operator of the land
disposal facility must also retain a copy
of the notice in his operating record
during the period of the extension and
for at least 3 years thereafter.
8. Progress Reports and Revoking the
Extension
The Agency will monitor the progress
achieved by the successful applicant in
meeting the completion schedule
submitted in the application. The
applicant must submit progress reports
at intervals designated by EPA under
§ 268.4(h). Such reports must describe
the overall progress made toward
obtaining required permits and
constructing or otherwise providing
alternative treatment recovery or
disposal capacity. The report must also
identify any event which may cause or
has caused a delay in the development
of capacity, and summarize the steps
taken to mitigate the delay. EPA can
revoke the extension at any time if the
successful applicant does not make a
goodfaith effort to meet the completion
schedule.
The recipient of an extension must
also notify the Agency as soon as he has
knowledge of any changes in the
conditions certified in the extension
application. Such changes include any
proposed change in the site of treatment
• or land disposal, and any significant
proposed change (e.g., volume or
characteristics) to the waste subject to
the extension. Any such planned
modifications to the conditions may
subject the applicant to a re-evaluation
of his extension, and possible
revocation.
6. Proposed Procedures To Evaluate
Petitions Demonstrating Land Disposal To
Be Protective Of Human Health and the
Environment
1. Introduction
As noted in Unit H.A, a hazardous
waste referred to by section 3004 (d). fe)
or (g) is banned from land disposal
unless EPA determines that one or more
methods of land disposal of such waste
is protective of human health and the
environment. The Administrator is
authorized to find that land disposal of a
particular waste will be protective of
human health and the environment if an
interested person demonstrates, to a
reasonable degree of certainty, that
there will be no migration of hazardous
constituents from the land disposal unit
or injection zone for as long as the
wastes remain hazardous (42 U.S C
6924, RCRA section 3004 ((d)(l), (e)(i).
and (g)(5)). This demonstration is made
in the form of a petition to the EPA
Regional Administrator or authorized
State program director. A petition may
be submitted by any interested person,
including any generator of a hazardous
waste or any owner or operator of a
land disposal unit (as defined in RCRA
section 3004{k)). A petition may be
submitted to the Agency at any time
prior to the effective date of the ban, or
at any time after the ban becomes
effective.
The statutory requirement for an
application by an interested person is
intended to place the burden on the
applicant to prove that a specified waste
can be contained safely in a particular
type-of disposal unit or injection zone.
The nature of the facility and the waste
must assure that migration of hazardous
constituents will not occur while the
wastes still retain their hazardous
characteristics and present a potsntial
threat to human health and the-
environment. This demonstration can be
made either for a particular facility by
an individual applicant, or for a class of
facilities with like natural hydrogeologic
conditions. The Agency believes,
however, that an adequate petition
demonstration for a class of facilities
with like natural hydrogeologic
conditions may be technically
complicated depending on site- and
waste-specific characteristics. The
Agency requests comments on the
feasibility of such a demonstration and
is interested in specific examples of
classes of facilities that are in like
natural hydrogeologic conditions.
If the Agency grants a petiton, the
subject waste may be managed in that
land disposal unit as long as the unit is
in compliance with all applicable
requirements. The granting of a petition
does not relieve the owner or operator
of the land disposal unit from any
obligation to comply with applicable
technical standards (e.g., the
requirements to install a double liner
system in the case of certain landfills
and surface impoundments).
The standard to be applied in
determining whether a petition will be
granted is whether there has been a
demonstration, to a reasonable degree
of certainty, that there will be no
migration of hazardous constituents
from the disposal unit or injection zone
for as long as the wastes remain
hazardous.
-------
/ «aL Si. Ste^D ? Tua^ay, January 14. Iflac. V ifr aposed -Eiila*
a case-by-case exteaaioawill
considered. EPA believes that Congress
intended the variance and extension
provisions of section 3004(h) to
encourage the development of safe
alternatives to land disposal. Since 48
months (i.e., the maximum 2-year
variance under section 3004(h)(2) plus •
the maximum 2-year case-by-case
extension under section 3004{hX3H is
the longest delay in implementing the
restrictions that Congress appeared to
contemplate, EPA believes Ihat it is
appropriate to adopt this thneframe as
an outside limit for Ae consideration of
extension requests. The •thnefeame
during which the Agency will allow
extensions to occur, therefore, will be 48
months after the ban effective dates if
no variance is granted. Should EPA
grant a variance to- the ban effective
date, this 48 months will decrease by the
duration of the variance. For instance, if
a 2-year variance is grantedr.all
extensions maat terminate .2-years fmm
the ban effective -date. As a practical
matter, this means that the duration of
the extensions {starting with a maximum
extension of 1 year wttfc a 1-year
renewal) wiH bwrnmy starter as more
time elapses ketaceen Ae aobedaued
effective date and the date «f *e
extension application. Na efctessiens
would be granted to exceed-the
statutory maximum of 2 years.
3. Length of the Case-by-Case Extension
Section 3004(h)(3> specifies that the
Agency may grant the first extension for
up to 1 year. However, an extension of
less than 1 year will be granted if, in
EPA's judgment, less than 1 year is
required to provide the needed capacity.
If the development of capacity will take
over 1 year, the Agency wifijtamsider a
time period of over 1 year for planning
purposes. However, in order to comply
with section 30e4(h)(3}, fee extension
must be officially Tene-wed after
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1700
two" demonstration. If a site has
characteristics that indicate that a tier- -
two demonstration will not be
appropriately conservative, then a more
complex "tier three" demonstration will
be required for a successful petition. The
Agency would like commenters to
identify characteristics that would make
the Tier 2 demonstration inappropriate.
The Agency will consider requiring that
petitions for such sites be based on
demonstrations with more complex fate
and ti-ansport models appropriate to the
tier-three level of sophistication.
In the second tier, a petitioner could
base the demonstration on the results of
inputting site-specific, data in the models
used to develop screening levels. The
petitioner would be required to use site-
specific data or conservative
assumptions in lieu of all data points
included in the monte carlo analysis
used to establish screening levels. The
petitioner will also have the option of
using other simple fate and transport
models as they are appropriate to the
site- and waste-specific scenario.
A simplified model is one that
accounts for only the most important
physical phenomena. It is important to
understand that the use of simplified
models will only be acceptable if
assumptions that account for
phenomena not modeled or not taken
into account are reasonably
conservative. The uncertainty of the
representativeness of a simple model
has to be tempered with sufficiently
conservative assumptions to ensure that
the model has sufficient validity to be
used in the petition decision. The
petitioner must satisfactorily
demonstrate the validity of alternative
simplified models for the site and waste
considered in the petition.
The central goal of the second tier is
to usually allow the petitioner, with
minimal effort, te determine whether
concentrations of the hazardous
constituents in the wa«te leachate will
not result in concentrations that exceed
the established health and
environmental standards at the point or
points of potential exposure. (The term
pomt(s) of potential exposure" will be
defined later in this section.) Thus, the
second tier centers on the fate and
transport of the hazardous constituents
from the disposal unit to thepoint(s) of
potential exposure. If the petitioner can
demonstrate that the established
screening and environmental based
standards are not exceeded at the point
or points of potential exposure, he will
not be required, ta perform any analysis
of the existing or future population that
may be in proximity of the site.
There may be situations where waste
constituent concentrations are in excess
of the Screening/Treatment Standards,
wbut because of unique site-specific
factors {such as where exposure can be
demonstrated not to occur), land
disposal may still be protective of
human health and the environment. In
this event, using appropriate data, the
petitioner may be able to omit the fate
and transport analysis.
Petitioners who fail at the second-tier
level of analysis have the option of
moving onto the third tier of the
protocol, which involves more detailed
site analysis and the use of more
sophisticated fate and transport models
to demonstrate that a hazardous
constituent of a waste will not exceed
health based standards at the point or
point(s) of exposure. The use of more
sophisticated models will naturally
require collection and use of more site-
specific data and a greater effort for the
analysis. The main goal of using more
sophisticated models is to reduce the
uncertainty of the results, and, therefore,
allow the use of more realistic
assumptions, computational algorithms,
or actual data in the place of
conservative assumptions. If the
petitioner can demonstrate that the
established screening and
environmental based standards will not
be exceeded using a more sophisticated
third-tier site-specific analysis, the
petitioner will not be required to
perform any analysis of future or
existing population in proximity of the
Slt6.
The petitioner will also have the
option to use any other data or analyses
in conjunction with fate and transport
analyses to show that, in the event of an
exceedance of the screening and
environmental standards,
concentrations at the point or points of
potential exposure will still not
endanger human health and the
environment. Using an approach that
does not rely strictly on fate and
transport modeling may result in a
considerably greater effort on the part of
the petitioner, and also for the Agency
when reviewing the petition; If the
petitioner plans to make such a
demonstration, he will be required to
consult with the Agency to establish the
nature and scope of such a
demonstration prior to submittal.
The amount of resources committed to
the development and review of a
demonstration in the third-tier would
increase significantly, depending on site-
and waste-specific factors, as compared
to a second-tier demonstration. To the
extent possible,.the Agency will provide
guidance to the petitioner as to what
level of effort, in terms of data collection
and/or analysis, will be needed to
support such a petition.
The Agency is preparing a guidance
document that will provide a detailed
description of the protocol. The
document is entitled "Land Disposal Ban
Variance Guidance Manual." When the
draft guidance document is completed a
notice of availability of the guidance
will be published in the Federal
Register.
As an alternative to the proposed
approach, the Agency is considering
limiting the eligibility of interested .
persons to petition the Agency to those'
generators of banned wastes for which
no acceptable treatment is available.
Where acceptable treatment exists and
is available, the generator of a banned .
waste would be required to treat the
waste to meet the section 3004(m)
standards. The Agency believes that
support for this position may be found in
the statement of congressional policy
that "reliance on land disposal should
be minimized or eliminated", and that
land disposal. . . should be the least
. favored method for managing hazardous
wastes" (section 1002(b)(7}). The statute
further points out that Congress seeks to
protect human health and the
environment and conserve natural
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 I003(a)(6)} Therefore, the
Agency is considering a requirement
that all banned wastes be treated
wherever adequate treatment
technology is available. A drawback to
this alternative approach is that it would
force waste managers to treat their
waste even when they can demonstrate
that continued land disposal at their
respective site would not endanger
human health and the environment. The
Agency is requesting comments on this
alternative approach, and the
corresponding limitation on the
eligibility of an interested person to
petition the Agency to remove a ban on
the land disposal of an untreated
hazardous waste.
2. Performance Standard
a. "(N)o migration. . .for as long as
the wastes remain hazardous." Under
today's proposal, as noted above, the
performance standard of "no migration
. . .for as long as the wastes remain
hazardous" can be met if the petitioner
can demonstrate that, by the time the
constituent reaches a point of potential
human exposure, or a sensitive
environment, it will be at a
concentration level that does not
threaten human health or the
-------
Itagbtw
-W*
.
standard*o meanHwUtvariance can be
granted only in cases where it is shown
(hat any migration thatdoes occur from
the disposal unit will be at
concentrations that do hot pose a threat
to human health or the environment.
This interpretation is supported by the
statutory language itself and by the
legislative history. The statute provides
that -there will be "no migration of
hazardous constilnents. . .foras long
as ihe wastes remain hazardous" thus.
implying that same rrrigratkm would be
allowed as long as the standard -set by
the latterphrase is not violated. The
legislative ibiatery sheds some light on
the intended construction of fhe.se terms.
It notes thai Iftjke administrator is
requited .is find thai the-n«ture«f the
facility and the waste will asauce that
migrafioB of 1hev»astes wiH not occur
while the wastes still retain their
hazardous characteristic* in such a way
that would paesent any ihneat to human
health aai the^nvisonmeat" (Senate
Report Me. 9B-284 at page IS).
Accordingly, a petition omM be graated
if it is shown that the hazardous'
constituent* -that migrate beyond the
emit are at concentration levels that
would not pose a threat t» human health
and the environment. The approach
outlined today is founded upon this
interpretation.
The Agency believes that, ultimately,
petition review is properly a function of
the permit review process, and should.
therefore, be the responsibility of the
permit writer in authorized States, or the
regional EPA office (RO| for other States
not Sully authorized to maaage a RCRA
Subtitle C program. However. EPA
headquarters maybe involved™
petition review to resdwe .any
significant policy or technical issues that
may arise in a manner that ensures
consistency across all Stales and
regions. Responsibility will eventually.
be delegated to authorized States at
such time that each Stale iias received
final authorization, .amlijas an
acceptable peti&anaEiriew program in
place. In addition, EPA headquarters or
the ROs will be responsible for issuing a
notice for publication in the Federal
Register with an explanation of the
basis for determining that a method-of
land disposal is protective of human
health and the environment, as required
by section 3004(i). Where individual
States are authorized for petition
review, a notice will be published in a
manner thai constitutes legal notice
under State law. ' '!
If a permit has not already oeen
issued, the Agency believes that the
petition review will normally be
undertaken vin the :c#ntext .of ithe .fait
technicsilrewiew of the Part &pennit
application, since disposal unit, waste,
and site Information critical for petition
review is, to a large extent, fee same or
consistent with' permit application
information requirements. The Agency
believes that parallel review of a permit
application and a pettSon application is
the most efficient use of Agency
resources and wffl ensure complete and
consistent review of all inrermatien
regarding the disposal unit and its
operations. The Agency Iras net
however, decided S-peStten •approval
should be'contingent upon formal permit
issuance. The Agency requests .
comments on an appruatii that wowa
allow approval of a pefifioa to a facility
operation under interim -states., and on
an alternative approach that wmld
make petition neroew contingent upon
permit issuance including the
opportunity forpribfic participation. In
addition, ate Agency requests .comment
on the extent of public notice and
opportunity for public uuihui^ut to be
provided prior to final decision on a
petition.
As a matter of policy, the Ajgeacy is
proposing ihal the receipt of a petition
by the Agency or authorized State is not
considered to be a basis for delaying the
effective date of any prohibition on land
disposal of a specific waste. The Agency
expects that the preparation of a
petition, and adequate review, are
processes thai are likely to consume a
number ofmonflis. During this period of
time, the petition applicant will lie
required to comply with all restrictions
on land disposal, once Ike effective date
of such restrkJfifflns has heea reached. »
However.ihe statute,allows«a
extension .of ti».ban .effective date if it
is shown.Jw*M-atio. that the applicant
for the extension has contracted to
pro vide alternate treatment, recovery or
disposal capacity (including land
disposal capacity! ikat is pEBtectwe of
human heal* •and the eavkrasieRt
(Sectien 3804(hM3». The Agency solicits
comment OH -whether a contract to
dispese of waste in a unit for which a
petitkm decision is pending constitutes a
contract to prsv4de protec'toe
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Janaaty 14.1368 / Proposed
In BngpoEaopoaarel
airborne hazardous: constituents, EPA
does not propose to {trail kg,
examination to constituents posing harm
when inhaled. Thus, in identifying the
point of potential' exposure, EPA might
consider a situation in-which airborne
inorganic particulates are deposited in
me soil in concentration that present a
threat to human* health through direct
exposure (e.g., ingestion) or through
contamination: of undseriying drinfekig
water or adjacent surface water. H>A
might also eonsidter m situation in which
the surface imgratiett of volatile
constituents, causes, hana to Etonian
, health as a result of aceuinulatwni in
buildings or otherphysical structures.
c.".. .fTfo-areasanabf°seeaf
certainty.. .'*. The decree of certainly
ascribed to the element? of the petition,
demonstration wilt be lately eenttotted
by the waste-and site-specific factor*
and thean^tieaibraitatiansaf the
methods employed to characterize those
factors. The petition deHwnstrstioa i» a
risk-based process thatpjrorrdes for at
nsk assessment of the waste- and site-
specific scenaiior and the opportunity for
exercising risfc management decisions
on a site-specific level.
The-Agency will balance the-
importance of each element of a
demonstration; and its respective degree
of uncertainty, while making a risk
management decision on a petition. The
major elements of the petition
demonstration arec
(1) Exposure potetviwl using fate and-
fransport analyses.
(2) Existing- and future populations
siirrotHiding a site.
(3> Taxicoiogical data specific to the
<;onstituentsat ssife.
(4) Leachateeoacejitratioaaf
The Agency helieres that searees o£
uncertainty for each element cannot be
eliminated hot cais be reduced to »
reasonable- degree. The Agency farther
believes, t&at it wnifcfc not be possible ttt
quantify a reasonable dageee of
certainty far all pennatatians-of afte-
specific factors; that oet3a% to occur
m the petKfon process. Thftr/^ency also
considers that tfee major sources of
imcerta^ are profeafety from those
elements; a£ the demonstration thai
relate to kmg-tenn prediction* and are.
by their nature; not quantifiable.
Although, statistical analysis ean be
n "inni- -i mn i ' I &__!. ; I* *
«.- ^.uunjr u* me iKvutiicaj uaiat a
estimating the probability of the
occurenee of a significant senea of
events that influence potential
migration, the Agency betiev«s.that the-
"reasonable degree e£ certainty"
concept cannot be defined by *
statistical procethaas.
The Ageacy has. thetefore, choaea to-
prescribe certain methods tobeused-by
the petitioner to ensera reasonably high
quality data and analyses* and, thereby
reduce uncertainty to a reasonable
degree, rather than specifying that a
statistical test be applied to the entire "
demonstration. The prescribed methods
involve setting data quality-objectives,
tor data eollectian,, analysis, and
prediction. The testing and analysis
techniques abould be selected by the
petitioner and approved by the Agency
as appropriate for the. site- and waste-
specific scenario; La., the techniques
should reasonably accurately measusa
appropriate waste peoperties,
characterize, a tmospharic «M
hydrogeologie-conditions, in the field,
' reasonably determine waste and, site
interactions affecting the ultimate, fate of
the waste, and predict the moat severe,
long-term effects: on the air and water
resources, resulting from, the disposal of
the subject waste. K tfie petitioner has.
made a reasonable effort to assemble
high quality date, and analyses, the
Agency will consider the petition results,
to represent a "reasonable degree of
certainty.""
The protocol the Agency is developing
for evaluating petition demonstrations
win address the issue of certainty in a
manner appropriate to the tiered
approach discussed above- Qi essence.
the tiered'approach is designed to
handle waste- ano* site-specific
scenarios according to the degree of
certainty that critical elements can be
analyzed,, and according to tfterr
importance in making; a risk
management decision. The second tier
would1 be for waste anrfsrte scenarios
where s greater degree- of uncertaihtv
would be acceptafefe given a generafiV
favorabfe waste-- and site-specific "
scenario-. Forwaste- and site-specific
scenarios where conditions appear to be
margfinrf,. »fegfrer degree ofcertainty for
tfte critical elements wttt be required;
An integral feature of tne-petitron wif!
be tfte oVwefapment of quality control
(QC) procedures tailored to-the site- and
wasfe-speeiffc scenario. These
procedures\ri!F be specified5 by the
petitioner i»» qnaSty control pfan and
reviewed am? approved by fne Agency-
prior to submission of a petition to the
Agency. FartierMfwo fevef petition
demonstrations. QA^QG reouirenjento
witr bw necessasy «% for th* dat» ased
in tbeetaHonstration and for any fata
and transport analysis that does-Betase"
the unaiteiedSeBeet«ing-/Ereatnien«
Standard modelstfotaietieT^nw»le»ek
surBcfea% eanseevativv assumptions
may replace the need for-QA^QC
, requirements, tfeat woukt nermaHy be
•required fertcftiaJ Mte-specific data
used- to the analysis^
For ber-three petrtka demoiKtratioes.
the Agency may. perfona a qualftp
assurance IQA). audit of tfae petitioner's
data collection and analy/feai
procedarest on-siie testing aod
measttremeni pracedmas, and! computer
modeling and statistical analysis
procedures. The quality assurance audit
may include review of laboratory
mefeods;. inetading dapjieate analysia by
an independent laboratory, site visits
prior to and daring oarsite field
sampling^ independent air,, grotmd-and
surface-water n«mitoTinj£. and
independant taodehng; and testing of the
computer code and modeting
assumptions. The Agency beiieves that
emphasis on the procedures used by the
petitioner to. collect and: evaluate data
andtoperfomtsaBidationHiodfeangia "
most critical in-reducing ancertaintjr.
The Agency ha* chosen to require
strict adherence to the oaaftty control
procedure* a* agreed upon by the
Agency and petitioner as. the moat
effeethfe means of ensuring that die
entire peStion meete the reasoaabte
degree ol certainty; test. A goManse
manual will be available to aid the
petitioner in meeting the QA/QC
reqBirjement».The AgEney i* seeking
comments on the use of QA/QC
procedures a* described above, and on
alternative approa
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Federal Register / V6L Sl.vNo. 9? /. Tuesday.\ January 14, 198ft /> ftd^asefd Rules
environment. (See unitIII.D.6, for
discussion of environmental effects.) It
should be noted that this determination
of non-hazardousness is generally not
equivalent to a delisting determination.
(See discussion at units m.D 2.b.(2) and
III.D.2.C.) In order to make this
demonstration, the petitioner may have
to show that, as a result of the natural
chemical and physical processes at the
site, the hazardous constituents are
immobilized, diluted, or degraded
between the disposal unit and the point
or points of potential exposure such that
human health and the environment at
any point of potential exposure is
protected. In addition to the fate and
transport element of the demonstration,
the petitioner may have to incorporate
an analysis of future and existing
population in proximity of the site, and.
in the case of an exceedance of the
established RfD or a departure from
10~s for a risk-specific dose, a
demonstration that human health and
the environment are protected.
b. Point of potential exposure. The
point or points of potential human
exposure will be determined on a case-
by-case basis by the petitioner. There
are several alternative approaches to
defining the points. In addition, the
points of potential exposure may differ
depending upon whether migration via
air, surface water, or ground water is
being considered. The following
discussion focuses primarily on
migration of hazardous constituents in
ground water and surface water, and
only in regard to human exposure.
' One possible approach is to define the
point of exposure as the point at which
the closest drinking water well (or
surface water used for drinking water
purposes) is located. This approach
would ensure that any migrating
hazardous constituents are at
acceptable concentration levels by the
time they reach the closest existing user.
However, this approach does not control
for the possible location of additional
drinking water wells (or surface water
uses) closer to the unit at some future
time. Since the statutory standard
appears to call for protection of human
health over the long term, this approach
does not seem to be acceptable.
A second approach, which is being
proposed by the Agency is to designate
as the exposure point the closest point
or points at which a use of surface or
ground water for human,consumption
could be located. Under this approach.
the petitioner would identify an area
extending from the limit of the disposal
unit over which he or she can-ensure
long-term control of water resources:
The petitioner would demonstrate that
the controls in place would prevent
human exposure to hazardous
constituents in the ground or surface
water within this area. The point or
points of potential exposure would then
be designated at the edge of this area of
effective control, and the petitioner
would be able to make use of the
attenuative capacity of the surface or
subsurface area between the edge of the
disposal unit and the outer edge of the
area of effective control in developing
acceptable concentration levels. For this
approach to be acceptable, the controls
must be in place for as long as the
hazardous constituents within the area
of effective control remain at
concentrations hazardous to anyone
potentially exposed to such constituents.
If the petitioner is unable to establish an
area of effective control beyond the
disposal unit, the point of potential
human exposure would be presumed to
be at the edge of the disposal unit.
The Agency is interested in comment
on the kinds of controls that should be
considered. Under the law of most
States, is it possible to include a
provision in a deed that will ensure that
all subsequent owners are bound to
observe the use controls imposed by the
original owner? Would it be acceptable.
or preferable, to require that use be
limited through local zoning law? What
about State controls?
The Agency is also requesting
comment on a third approach for
designating ground water exposure
points. Under this approach, the
potential exposure point would be
assumed to be at the edge of the waste
management boundary, unless the
petitioner demonstrates that site-
specific factors justify selection of a
different point Petitioners requesting an
alternative point as the potential
exposure point would be required to
demonstrate that ground water use
between the waste management
boundary and the requested exposure
point is highly unlikely. This approach is
similar to the approach described
previously. The principal difference is
that this approach would allow
consideration of non-legal parameters
that influence ground water use, in
addition to legally enforceable
restrictions, when designating potential
exposure points.
Examples of site-specific factors the
Agency might consider include:
(1). Existing local ground water uses;
(2) Site proximity to existing ground
water users;
(3) Expected persistence of ground
water contaminants; and
(4) Likelihood of future ground water
use. considering:
a. Background aquifer quality;
b. Potential aquifer yield;
c. Institutional controls on ground
water withdrawal;
d. Availability of public drinking
water distribution systems; and
e. Current and expected land use of
adjacent properties.
Comments are requested on this
alternative approach to designating
potential exposure points. Interested
parties are also invited to submit, for
consideration, additional site-specific
parameters that could be used to
evaluate the likelihood of future ground
water use and their views on any of the
specific factors given above.
Another approach would be to
consider the point of exposure to be the
property boundary. However. EPA has
rejected the proposition that RCRA's
jurisdiction is limited to dangers
occurring outside hazardous waste .
management facilities. (See for example,!
45 FR 33184.) Accordingly, EPA does not |
propose to presume that the property
boundary is the point of exposure, but
will require that the petitioner justify thel
appropriate boundary based on a
demonstration of effective control.
The Agency is considering similar
options for defining the point of
potential exposure to airborne
hazardous constituents. The analysis of
available options is complicated by the
fact that it is much more difficult to
control exposure to airborne
constituents. The Agency would like to
consider an approach, analogous to that
outlined previously, under which the
point of potential exposure would be
coterminous with the area in which an
owner or operator could ensure that
there would be no exposure to
hazardous constituents at unacceptable
levels. However, the Agency believes
that such an approach would, in fact, .
provide the owner or operator with little I
of the intended flexibility. Because it is •
difficult to limit exposure to airborne
constituents, EPA expects that, in some
cases, the point of potential exposure
would be at the limits of the disposal
unit. In other cases, however, the point
of potential exposure could be
established at the limits of a waste ,
management area that is surrounded by
security fences, controlled access gates,
and warning signs. The petitioner must
be able to demonstrate that such
security measures are effective in
preventing access by local residents or
any employees that are not protected
from airborne contaminants. EPA is
requesting comments on whether other
points of potential exposure to airborne
emissions may be justified.
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1704
species or environraenMay.
1990, it is coneefoabte that a particular
waste nsay contain some hazardous
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Federal Register / Vol. 51* No. 9 /; Tuesday? January 14> 1986 / Proposed? Rules
provide an accounting of the ultimate
fate of the hazardous constituents. The
petitioner, therefore, may have to
demonstrate that the hazardous
constituent mass is degraded, diluted, or
immobilized, and not merely transferred
from one environmental medium to
another. During the degration process,
some hazardous constituents break
down to form new hazardous
constituents (i.e.. other constituents on
Appendix VIII). If the degradation
process produces additional hazardous
constituents. EPA proposes to require
that the applicant demonstrate that such.
degradation products also will not
migrate to the point of exposure in
concentrations that harm human health
and the environment. Because of state-
of-the-art limitations on the ability to
detect the presence of many degradation
byproducts that are not listed as
hazardous constituents, the Agency
does not propose to require such a
demonstration for these constituents
even though such constituents may
theoretically have an effect on human
health or the environment.
e. Time Frames. The statutory -
language prohibiting the migration of
constituents "for as long as the waste
remains hazardous" suggests not only a
substantive standard (i.e., no migration
in hazardous concentrations) but a time
component as well. EPA interpret this
provision to require the applicant to
demonstrate that the hazardous
constituents will not exceed acceptable
concentration levels at all points of
potential exposure as long as the
constituents retain the potential to harm
human health or the environment. In
practical terms, this means that EPA
will not only assess the potential for
migration in unacceptable
concentrations during the active life of
the facility,, but will also assess the
migration potential for what may be an
extensive period of time after closure.
The length of the assessment period
may vary-depending upon the pathway
of migration. For example, the exposure
posed by airborne constituents may be
relatively short-lived if volatilization
occurs only during the active life of the
unit. On the other hand, the exposure
due to volatilization may be long term if.
for example, constituents migrate
through the subsurface and accumulate
in buildings. The Agency believes that
the time period to be covered by the
demonstration can reasonably be
determined by modeling contaminant
migration in the air. ground water, and
surface water. As long as the model
results indicate that there is a possibility
that the maximum allowable
concentration of any hazardous
constituent could be exceeded at any
points of potential exposure, a complete
demonstration has not been made.
When the model results indicate that
concentrations have reached a level that
does not exceed the maximum
allowable level, and have begun an
irrevocable decline at all points of
potential exposure, then the
demonstration has considered a
sufficient period of time. In addition, the
Agency believes that the petitioner
should make a reasonable estimate of
' the maximum quantity of the subject
waste to be placed in the disposal unit
over the entire life of the unit, rather
than assume an infinite source of
hazardous constituents.
f. Consideration of Artificial Barriers.
The legislative history provides that in
making a petition demonstration, "the
applicant must sustain the burden
of ... [demonstrating no migration as
long as the wastes remain
hazardous] . . . without the use of
artificial barriers such as liners." It goes^
on to note that'"[artificial barriers "~
cannot provide the assurances
necessary to meet the standard." (S.
Rep. No. 98-284 at page 15.) EPA
interprets the above-cited language to
reflect cpngressional intent to foreclose
EPA from granting a petition on the
assumption that the "no migration"
standard has been met because a liner is
in place. In light of the fact that all liners
eventually leak, such an assumption
would clearly fail to provide the
"assurances" that Congress is seeking.
EPA does not believe that Congress
intended to preclude a more realistic
consideration of liner performance in
assessing when and if migration might
be expected to occui. Indeed, one could
argue that, in some cases by failing to
consider the effect of existing
containment mechanisms on constituent
migration. EPA would increase the
uncertainty of the petition analysis,
thereby failing to achieve those
"assurances" that Congress is seeking. If
EPA were to disregard the effect of
existing containment mechanisms
altogether, the Agency would be
obligated, to make numerous additional
assumptions about the migration of
constituents in a hypothetical setting
rather than under existing conditions. In
addition, it makes little sense to allow
generic consideration of liner
effectiveness in identifying screening
levels at which wastes may be land
disposed under section 3004(m) (see
discussion at Unit III. A.l.b.), but to
preclude a much more accurate, site-
specific consideration of liner
performance in the petition process.
Thus,, the Agency believes that some
reasonable projection of failure rates for
liners to the extent that liners or other
engineered systems may be appropriate |
in some petition demonstations.
However, it is expected that
consideration of liners will be critical to |
the outcome of petition deliberations
only in limited cases. At the tier-two or
three levels of sophistication, the
petitioner may rely on sufficiently
conservative assumptions as to the
efficacy of liners or other engmeered
systems, or, may employ specific
engineered component performance
data. In the event of a petitioner using •
specific performance data, the Agency
will require that appropriate QA/QC
procedures are employed to obtain such |
data.
A petitioner may be able to
demonstrate that waste will be
transformed to a non-hazardous or less
hazardous state while the containment
mechanism is still effective, so that upon
a breach of the system there would be .
no migration of hazardous constituents
in unacceptable concentrations. In such
a case, consideration of the liner would
have a direct bearing on the petition
decision. However, because the land
disposal restrictions program is aimed a j
preventing long-term as well as short-
term harm to human health and the
environment, a demonstration that
harmful migration would merely be
delayed due to the existence of a liner
would not be the basis for granting a
petition.
EPA solicits comment on appropriate
assumptions to be made concerning
liner failure. What factors should be
considered in assessing when the liner
will fail? To what extent are these
factors site-specific? Are there any
generic assumptions about liner failure
that could and should be drawn? What
other artificial barriers, if any, should be
considered in the petition process? WhaJ
is an acceptable level of certainty that
could realistically be obtained in an
analysis of the performance of man-
made systems?
g. Environmental Effects. In addition
to demonstrating that there will be no
harmful effects on human health, the .
petitioner is required to demonstrate
that there are no harmful effects on any
aquatic biota, wildlife, estuaries,
vegetation, or protected lands. This
demonstration may be met purely on thel
basis of fate and transport analysis that f
shows that concentrations of hazardous |
constituents would be at or below the
established levels that are protective of I
the environment at the point or points of
exposure. The Agency proposes that, at
a minimum, the following types of
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Federal Register / VoL 51: No. 9 / Tuesday, January 14, 1986 / Proposed Rates
Specifically, the Agency seeks
comments on the comprehensiveness
and consistency of its approach to
determining that the petition standard is
achieved with each of the various
methods of land disposal.
4. Demonstration Components
a. Waste analysis. The petitioner
should perform appropriate tests of the
subject waste to characterize fully the
waste's chemical and physical
characteristics. Sampling of the waste
for testing and analysis must be frequent
enough to account for the variations
over time of the waste's characteristics.
Appropriate sampling frequencies and
techniques and acceptable statistical
procedures should be developed on a
case-by-case basis, in consultation with
the Agency. The petition demonstration
will, therefore, be based upon a waste
with particular chemical and physical
characteristics, with the corresponding
degrees of variation. If the Agency
approves a petition demonstration, such
approval will apply strictly to a waste
with these particular characteristics. If.
over time, a particular waste stream
changes substantially so that it no
longer exhibits the particular chemical
and physical characteristics originally
specified in the petition, the petitioner
must notify the Agency or authorized
State of the change, and the
demonstration must be resubmitted and
reevaluated. Until such reevaluation
occurs, the waste is not permitted to be
placed in the land disposal unit.
The Agency may require periodic
monitoring and analysis of the waste to
determine if significant changes in the
waste characteristics have occurred.
Alternatively, the Agency may require
that the petitioner notify the Agency
whenever a change in the waste
characteristics has occurred or is
expected to have-occurred, rather than
regular monitoring, analysis, and
reporting requirements. The Agency is
considering various means of assuring
that the waste characteristics have not
changed dramatically over tfinei thereby
invalidating the petition demonstration.
and is seeking comments on me most
effective approach.
In addition to information on waste
characteristics, the petitioner must
estimate volumes of the subject waste to
be disposed, on a yearly basis, for as
long as the land disposal unit is capable
of accepting wastes, since the volume of
waste ultimately disposed is a crucial
factor in the petition demonstration. The
petitioner can rely upon historical data
and estimate changes in volume in the
future, based on industrial activity or
advances in technology. The Agency
will accept a reasonable projection of
waste volume but will review, following
the .approval of any petition
v demonstration, information on actual*
volumes of the subject waste accepted
at the disposal unit during the course of
site inspections. If actual volumes
exceed the projected volumes so as to
call into question the results of the
petition demonstration previously
approved, the Agency will reevaluate
the demonstration and may require that
the petition be resubmitted. If there is no
valid basis for projecting the annual
volumes of the subject waste to be
disposed throughout the active life of the
disposal unit, the petitioner should
assume that the total volume is equal to
the design capacity of the disposal/unit,
and that the annual volume is constant
over the expected life of the disposal
unit.
b. Human Exposure and Risk
Assessment. There are documented
scientific research data available to
verify that certain organic constituents
are degraded to their harmless
components due to such processes as
photolysis in the atmosphere, and
hydrolysis and biodegradation in the
subsurface. Inorganic and non-
degradable organic constituents can be
immobilized due to chemical or physical
adsorption to soil particles in the
subsurface, and can be diluted due to
the dispersive effects of air movement
and ground water and surface water
flow. The petitioner, depending on the
waste- and site-specific scenario, may
have to demonstrate that the
degradation, dilution, and'
immobilization processes are effective
for the subject waste, under the
•environmental conditions as they exist
at the disposal unit site.
Concentration levels at the point or
points of potential exposure that are ,
protective of human health must be
determined for noncarcinogenic
constituents and for carcinogenic
constituents of the subject waste. The
sophistication of the'analysis to show
the degree of exposure will depend upon
the site- and waste-specific scenario.
The Agency is proposing that the
Reference Dose (RfD) (See Unit IH.A
regarding the establishment of
screening/treatment standards) be
adopted as the screening level for
noncarcinogehs and that a Screening'
level concentration based on a risk-
specific dose be adopted for
carcinogens. Because certain site-
specific factors may impact the degree
to which an RfD could be acceptably
exceeded and may impact'the selection
of the risk-specific dose, the petitioner
may be required to perform an analysis
of the size of the potentially exposed ~"
population, both current and future, and
,f various other factors related to the
assessment and management of risk.
TheTesults of this analysis would be
used to determine a level that is
protective of human health and the
environment. (See Unit IH.A.l.b. for a
more detailed discussion of the-
screening levels.) The petitioner must
demonstrate that hazardous constituents
will not migrate from a disposal unit in
concentrations that will cause an RfD or
risk-specific dose to be exceeded at any
point of potential human exposure. In
order to determine whether an
unacceptable concentration of
hazardous constituents will exist at the
edge of the disposal unit, the petitioner
must calculate the maximum
concentration in the air, ground water,
surface water, and soil, and compare it
with the RfD or risk-specific dose at the
point of potential exposure, taking into
consideration the attenuation derived
from natural processes such as
photolysis, hydrolysis, biodegradation.
and adsorption in the subsurface.
surface, and atmosphere, and, in. some
cases, taking into consideration the size
and nature of the potentially exposed
population. Again, the sophistication
and scope of the analysis of these
critical elements will depend upon the
waste- and site-specific scenario.
For noncarcinogenic contaminants,
predicted concentration levels at or
below the RfD will.be considered
protective of human health.
Concentration levels above the RfD may
also be considered protective if the
petitioner can demonstrate that such
concentrations are, not expected to
cause adverse health effects. Such a
demonstration by the petitioner, and its
subsequent review and evaluation, will
require the exercise of considerable
professional judgment by qualified •
lexicologists. The petition process will.
only address unique site-specific factors
that justify exceeding an established
RfD. Challenges to'the established RfD
that are not based-on site-specific . •
factors must be reviewed using
established Agency protocol.
The Agency proposes to use the
following-crfteria'for determining
whether or not a petitioner may exceed
the estabKshecNRfD fora
noncarcitoogenifc constituent: - - '
(AJ Exposure Criteria , ..
(i) Other potential or actual sources of
exposure to the saine or similar
constituents:" " <••••..••
(ii) The level and type of uncertainty
inherent ift the models used to predict
potential exposure to the surrounding
population:
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F«fam! Raster / VoL si, No. 9 / Tuesday. January 14, 1986 / ftqporod Rules
the same time, leads to unambiguous
decisions regarding the land disposal of
previously restricted hazardous wastes.
Comments are requested on how well
each of the above approaches meets
these stated goals.
In the case of certain characteristic
wastes (i.e., wastes that are hazardous
due to ignitability, corrosivity, or
reactivity) with which no additional"
hazardous constituents are associated, a
concentration level is not a valid
. criterion for determining whether the
performance standard has been met.
Therefore, the petitioner is required to
demonstrate that the waste has
undergone chemical or physical
changes, such that when the'waste
eventually migrates it no longer exhibits
the characteristics that originally caused
the wastes to be classified as hazardous,
at the point(s) of potential exposure.
This demonstration, in effect, would
result in the declassification of the
waste as hazardous, as defined at 40
CFR 261.3. The petitioner would also be
required to demonstrate that no
additional hazardous constituents were
present in the original wastes, or that
such hazardous constituents do not
result in a violation of the standard as
described previously.
i. "[Disposal unit or injection zone".
The statute requires that there be a
showing of "no migration. . . from the
disposal unit or injection zone for as
long as the wastes remain hazardous".
The legislative history makes clear that
the term "injection zone" is to be
defined as prescribed hi existing EPA
regulations at 40 CFR 146.3 (S. Rep. No.
98-284 at page 16). Thus, the term refers
to a geological formation and is not to
be construed in terms of surface
property ownership (S. Rep. No. 96-284
at page 15). The term "disposal unit" is
not expressly defined in the statute or.
legislative history applicable to section
3004 (d), (e), and (g)[5). However, it is
presumed that Congress is aware of the
usage given to this term by EPA (see
e.g., 47 FR 32289), and intended that the
term be given like meaning in the
context of these sections. Indeed, in
legislative history addressing another
section of the new law, the House
Committee on Energy and Commerce
explicitly provides that the term "unit"
be defined as consistent with the
Agency's existing use of the term and
"as further defined by EPA in the future"
(H. Rep. Report No. 98-198, Part 1, at
page 60). Unless there is an expressed
indication of contrary congressional
intent, a term is given consistent
meaning throughout a statute.
Accordingly, for purposes of the petition
process, the term "unit" will be defined
with reference to the agency's present
use of the term. Thus, a unit is defined
as a "contiguous area of land on or in
which waste is placed, or, the largest
area in which there is a significant
likelihood of mixing waste constituents
in the same area." Thus the unit would
include the area contained within the
engineered components and any
excavated areas of the surface or
subsurface that support the engineered
components. An individual surface
impoundment, waste pile, or land
treatment unit is a "unit" for purposes of
this discussion. .In the case of landfills
that are designed as a series of
separately lined trenches, each
individual trench is a separate unit. For
the purpose of the land disposal
restrictions program, the Agency also
proposes to characterize salt dome
formations, salt bed formations and
underground mines and caves as units.
The petitioner must identify the
boundary of any unit or units that may
be involved in the management of the
banned waste that is the subject of the
petition. This boundary becomes the
compliance point, for the purpose of
demonstrating that human health and
the environment will be protected. In the
absence of an acceptable demonstration
of effective long-term control of an area
beyond the boundary of the disposal
unit, this boundary is also the point of
potential human exposure.
3. Applicability of the Performance
Standard
a. Landfill's, surface impoundments,
and waste piles. Land disposal units
that are located at the land's surface,
contain such engineered components as
a liner system and a leachate collection
and removal system, and are often
closed by constructing a cover system,
include landfills, surface impoundments,
and waste piles. Due te their similar
characteristics, these types of units will
be expected to make similar types of
petition demonstrations. For the purpose
of making this demonstration, the limits
of the disposal unit are established at
the edge of the liner or excavated liner
foundation at all landfills, surface
impoundments, and waste piles; at the
open face of an active landfill cell; at the
surface of an active surface
impoundment; at the surface of an active
waste pile; and-at the surface of the
cover of a closed landfill cell, surface
impoundment, or waste pile.
hi. Land treatment units. Land
treatment units do not typically have
liners or leachate collection and removal
systems. For the purpose of this
demonstration, therefore, the limits of
the disposal unit are the lateral and
vertical extents of the treatment zone, as
established ia the permit in compfiaace
with 40 CFR 264.271(b). With regard ta
air emissions, the surface of the •
treatment zone is considered to be the
limits of the disposal unit
The Agency believes that much of the
waste and site testing, analyses of
degradation, and immobilization of
constituents, that is already required for |
a land treatment permit should satisfy
the testing and analysis requirements of |
a petition demonstration. Rather than
requiring duplication of these tests, the
Agency would allow the use of the same |
testing and analytical results for the
permit application and a petition
demonstration, as long as Jhe
requirements of both are met. For a
petition demonstration, this would
include the air and surface water
pathways and a consideration of the
likely long-term effects of migration (i.e.,
beyond the operating period of the land
treatment unit). If the petitioner failed to |
provide the minimum information
required under 40 CFR Part 270 relevant
to the land treatment demonstration, the
petition would be subject to rejection.
c. Underground injection wells. The
approach for petitioning for removing a
ban on underground injection of
hazardous waste will be discussed in a
separate Notice of Proposed Rulemaking |
to be published in the Federal Register,
regarding a separate rulemaking on
hazardous wastes that are managed in
underground injection wells (section
3004(f) and 3004(gJ).
d. Other methods of land disposal. In
addition to the above methods of land
disposal, section 3004(k) defines land
disposal as including any salt dome
formation, salt bed formation,
underground mine, or cave. Other types
of waste management practices (e.g.,
open detonation units) may also be
included in the section 3004(k) definition
of land disposal. (See Unit I.C.I.)
Currently, the Agency has no specific
guidelines for demonstrating no
migration with respect to these or other
forms of land disposal. A petitioner may
attempt to demonstrate no migration of
hazardous constituents in unacceptable
concentrations by applying the general
concepts discussed in this proposed
rulemaking in a reasonably defensible
manner. The Agency will review such
petitions in a manner consistent with
any other petitions received. Specific
criteria for determining whether the
petition standard will be achieved
would be developed on a case-by-case
basis.
The Agency is seeking comments on
the applicability of the performance
standard to each of the types of land
disposal discussed in this unit.
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1708
1986 / Proposed Rides
may be subjected. The petitioner would
still be responsible for determining the
effect on the MEI, using the same human;
health criteria used in determining the
nationally applicable screening
concentration levels. Population
information would be used to set the
acceptable level of certainty to be
attained in the complete development of
the petition demonstration.
The Agency requests comments on the
proposed approach and on the
alternative approach. The Agency has
some concern that requiring any
population analysis may result in delays
m preparing and reviewing petitions,
due to the effect involved in collecting
and analyzing information pertaining to
various aspects of population analysis. '
Therefore, the Agency also requests
comments on an approach that would
not require any population analysis.
Under such an approach, the decision on
any petition would be based on the
predicted effects on the MEI, although
the petitioner could supply information
on aggregate population effects, at his
discretion.
c. Site characterization. The petitioner
must perform a characterization of the
site of .the disposal unit to establish
actual field conditions in the
trrosphere, at the surface, and in the
t, .bsurface. The depth and scope of the
characterization will depend on the
waste- and site-specific scenario. Much
of the information may already have
been collected and analyzed to fulfill the
other information requirements of Part
204, Part 270, or applicable State or local
requirements. Site-specific data may be
among the most important factors in the
petition analysis, since the ultimate fate
of any hazardous constituents of the
subject waste is determined by the
natural assimilative processes affecting
degradation and immobilization. The
.Agency, therefore, believes that
accuracy and precision in the
measurement and analysis of all
environmental parameters are extremely-
crucial to a successful petition
demonstration. The Agency will provide
guidance to the petitioner on the types
of data that must be presented and the
required analyses. Test methods to be
used, frequency and types of sampling
and analysis, and data quality
objectives must be submitted to the
Agency in a quality control plan. The
amount of data and the extensiveness of
the analysis will be determined on a
rase-by-case basis, depending on the
complexity and nature of the entire
demonstration. At a minimum, however;
the petitioner is expected to provide all
information that is relevant to the
demonstration from the Part B permit
application (40 CFR Part 270). Failure to
provide the relevant minimum
* information required for establishing the""'1
Subpart F ground water monitoring
program would constitute justification
for rejection of the petition. As
additional site characterization
information requirements are included
in Part 270, related to other
environmental media such as air and
surface water, this additional
information will also be required of the
petitioner.
d. Evaluation of performance of
engineered systems. The petitioner
should consider the design, operation,
maintenance, and expected performance
of the engineered systems of the
disposal unit to the extent that such
systems affect the.quantity, or quality of
the hazardous constituents that may be
released into the environment. The
petitioner should have prepared and
analyzed most of the required
information in conjunction with
preparing a RCRA Part B permit
application. The petitioner may use this
permit information as a starting point for
estimating the eventual failure
mechanisms and resulting release of
hazardous constituents.
The petitioner may be able to
demonstrate that the hazardous
constituents undergo chemical or
physical transformation processes
within the disposal unit prior to failure
of any liner, cover, or other engineered
components so that the hazardous
constituents that migrate from the unit
are not at hazardous concentrations, or
so that the material that eventually
migrates into the atmosphere or
subsurface no longer contains any
hazardous constituents or any other
characteristics that may have qaused
the waste to be hazardous. In doing so,
however, the petitioner would be
required to identify specific chemical
and physical processes (e.g.,
biodegradation and hydrolysis) that
result in a permanent transformation of
the waste well in advance of the end of
the expected performance life of the
engineered components. Appropriate
testing is required to demonstrate that
the specified chemical and physical
processes will occur, and that any
reaction byproducts that may also be
hazardous are identified and quantified.
Because little technical data are
available on the actual degradation and
immobilization of hazardous wastes, or
On the long-term performance of
engineered components, the Agency will
evaluate such a demonstration by using
conservative assumptions regarding the
performance of the engineered systems
and the accuracy and precision of the
analytical methods used in the
demonstration.
5. Request for Comments
The Agency is seeking comments on
the types of waste and site situations
that are most likely to meet the
performance standard, and is seeking
data on the various technical aspects of
such a demonstration. Specifically, the
Agency is interested in information on:
a. What types of wastes may meet the
standard by rapid degradation or
immobilization in a land disposal unit
environment?
b. What natural processes in the
atmosphere, surface and subsurface
provide long-term control of certain
waste constitutents? Can results of field
testing, and laboratory studies
applicable to field situations, with
specific wastes be made available to the
Agency?
Other comments are sought on various
technical matters related to the petition
demonstration. Specifically, comments
are requested on:
a. Specific transformation and
immobilization rate data for hazardous
constituents under specific
environmental conditions;
b. use of a dispersivity factor in
ground water transport models and
models for other media;
c. Criteria for evaluating the effect of
engineered components on the ultimate
fate of hazardous constituents;
d. Criteria for evaluating the
consequences of floods, earthquakes, or
other natural and potentially significant
phenomena;
f. Criteria for model validation.
H. Restrictions on the Storage of Waste
That is Prohibited From Land Disposal
Pursuant to section 3004(j) of.RCRA,
any waste that is prohibited from one/or
more methods of land disposal is also
prohibited from storage, unless the
Storage is solely to accumulate sufficient
quantities of the waste to allow for
proper recovery, treatment, or disposal.
The Agency does not interpret this
provision as applying to wastes that
have been treated in accordance with
treatment standards under section
3004(m). because under the language of
section 3004(m)(2) such wastes are not
prohibited from land disposal. In
addition, the Agency does not interpret
this provision as applying to wastes and
units that have been the subject of a
successful petition demonstration.
However, such wastes may be stored
only in a unit that is covered by a RCRA
permit or, is under interim status, and is
covered by the petition.
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Federal Regater / Vqi. 51, No. a / Tuesday. January 14. 1986 / Proposed Rules
1787
(iii) The nature of the potentially
exposed population.
(B) Toxicologies! Criteria
(i) The slope or slopes of the dose-
response curves for the health effects
attributable to a threshold constituent;
(ii) The frequency and magnitude of
potential exposure to a threshold
constituent.
The Agency expects that the petitioner
will meet with the petition reviewer
(EPA or the authorized State) during the
pre-petition conference to discuss the
specific demonstration necessary to
support a concentration in excess of the
established RfD, and to discuss the
above criteria that will be used in
reviewing the demonstration.
In determining a level for any
carcinogenic constituents that will not
present a threat to human health, the
Agency will consider the following
criteria:
(A) Exposure Criteria
(i) Other potential or actual sources of
exposure to the same or similar
constituents;
(ii) The level and type of uncertainty
inherent in the models used to predict
potential exposure to the surrounding
population;
(in) The potential current and future
risk to individuals from the activities of
the disposal unit:
(iv) The size and nature of the
potentially exposed population.
(B) Toxicological Criterion
(i) The level and type of uncertainty
inherent in the data used to estimate
health risk.
Consistent with decisions that the
Agency has made in the past, the
maximum exposed individual (MET) risk
level for each petition will be set to
correspond to a statistical lifetime risk
in the range of 10"4 to 10~7 using 10~s as
a point of departure. This is equivalent
to preventing the person most exposed
to the hazardbus constituent of concern
from having more- than a 1 in 10,000 to a
1 in 10.000.000 chance of developing
cancer. Within the range of 10~4 to 1&~7,
the actual level chosen for each petition
will depend upon the analysis provided
by the petitioner on the size of the
aggregate potentially exposed
population, considering the period of
time that the wastes remain hazardous.
The Agency will thoroughly evaluate
the strength of the evidence of
carcinogenicity, the basis of the
petitioner'Siexposure assessment and
other site-specific factors that may
affect aggregate risk. Where the
evidence of carcinogenicity is weak,
where extremely conservative exposure
assumptions have been made, and
where the predicted exposure
assessment has been completed with a
high degree of confidence, the Agency
would probably not require a reduction
in risk beyond the higher end of the
range (i.e., 10" * to 10" ^ In other cases
where the aggregate exposed population
is relatively large, the evidence of
carcinogenicity is strong, or the
predicted exposure assessment is
relatively uncertain, the Agency would
not allow an MEI risk level greater than
10~6 or 10"7. With a larger population
being exposed, there is a greater chance
that an unacceptable number of
incidents of cancer would actually occur
in the populationfWith a larger
population the Agency would be more
likely to adopt a more conservative risk
level, taking into account other factors,
such as the assumptions used in the
models that estimate risk levels, since
an incorrect decision would have more
severe consequences.
In addition to using population as a
factor hi determining how conservative
the Agency may be in granting petitions,
the Agency will also consider future
events/processes such as earthquakes,
floods etc., as they may modify
exposure. Exposure scenarios are likely
"to change over time with major
differences occurring when the unit is
operating compared to the post closure
care period. Thus, the Agency will
require the consideration of events and
processes that are potentially capable of
modifying exposure.
Where these events and processes
and their effects are identified with a
reasonable degree of certainty, the
Agency may hie able to be more flexible
hi making risk management decisions
regarding petitions. If these events or
processes cannot be identified with a
reasonable degree of certainty the
Agency will tend to take a more
conservative approach to making risk
management decisions.
The Agency believes that this
approach provides flexibility to approve
or deny petitions based on the
magnitude of potential current or future
human health effects. Rather than
establish a single MEI risk level to be
applied to all petitions, the proposed
approach allows the petitioner to
include all factors relevant to potential
risk to be examined in a local, site-
specific context where the best decision
can be made.
Although this approach involves a
fairly sophisticated analysis by the
petitioner and extensive review by the
petition reviewer, the Agency believes
that such site-specific decisions must be
made on the basis of a thorough
analysis of the effects on the local
population. The Agency intends to reject |
petitions where the probability of
expected cancer incidence from the
continued land disposal of a banned
waste would be significant. Where it
can be demonstrated, to a reasonable
degree of certainty, that continued land
disposal is a safe management practice,
the Agency will approve the petition.
The Agency is considering an
alternative approach for including total
population in the decision to approve or
deny a petition. This alternative
approach would involve an'analysis of
the effects on the MEI using the same
criteria (i.e., the risk-specific dose and
the RfD) used for setting the screening
concentration levels, rather than
allowing a site-specific determination
based on the factors previously
discussed. The analysis of the potential
aggregate exposed population would not
be used to determine how much of an
excess concentration above the RfD is
allowable or to set an MEI risk level.
The alternative approach would,
however, allow population information
to be used to determine the acceptable
level of certainty to be attained by the
petitioner in all data and analyses
included in the overall demonstration.
To meet the "reasonable degree of
certainty" test required by the statute,
the Agency is requiring that the
petitioner prepare a comprehensive
quality control plan setting out data
quality objectives to be achieved in all
waste and environmental testing and
measurements, and hi modeling
analyses. Under this alternative
approach, the Agency would allow less
stringent quality control .procedures and,
therefore, a higher degree of uncertainty,
where the current and expected future
population size is relatively small, since
the consequences of an incorrect
decision would be less severe than in an
area where population size is relatively
large. Less stringent quality control
procedures would reduce the intensity
of the data requirements, reduce the
thoroughness of the analysis, and reduce
the degree to which laboratory data and
model results must be validated by
comparison to field test data. Where
population size is relatively large, the
quality control procedures would
become more stringent to reduce the
degree of uncertainty.
The critical feature of this approach is
allowing the size of the potentially
exposed population to have a direct
impact on the petition demonstration, in
terms of the level of effort required on
the part of the petitioner and the
likelihood of the petition being
approved, without compromising on the
level of risk to which any individual
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1710
federal Rggjgt
No. 9 / Tuesday, famtaiy 14. 1986
informatiott that would be useful hi
fulfilling the relevant atatutorr
requirements.
The Agency-will address disposal of
hazardous waste into deep injection
wells at a later date in accordance with
the deadlines established in section 3004
If) and (g) of RCRA. Therefore, under
9 268.1 hazardous waste disposal in
injection wells is exempted from the
regulations being proposed today.
A. Land Treatment
1. Introduction
Under section 3004(k) of RCRA, land
disposal of hazardous waste is defined
to include ". . . any placement of such
hazardous waste in a ... land
treatment facility. . . ." As a result, the
Agency must make land disposal
prohibition determinations for land
treatment of hazardous wastes in
aceo'rdance with the requirements and
schedules of section 3004 (d). (e), and
(§)•
The Agency intends to fulfill these
statutory requirements for land
treatment facilities by developing, if
possible, a back calculation model and
database specifically for land treatment.
However, due to the difficulties involved
in characterizing the complexity and
variability of land treatment and the
very limited availability of critical data
(e.g., biodegradation rates), it is not
possible for the Agency to develop,
review, and approve a back calculation
model and database specifically for land.
treatment within the deadlines
established under section 3004{e). In
view of the desirability of developing a
land treatment-specific model and
database, and the current inadequacy of
time and data, the Agency proposes the
iollowing approach to address land
treatment of hazardous wastes under
section 3004 (d), fe), and (g).
a. The Agency will continue to
develop a land treatment-specific back
calculation model and database.
b. To meet statutory deadlines that
occur before the land treatment-specific
back calculation model and database
are available, screening concentrations
for land treatment win be me same as
screening concentration* for-other types
of land disposal units.
c. If and when an appropriate and
adequate land treatment-specific back
calculation model and database can be
developed, the Agency will use them to
establish subsequent land treatment
screening concentration determinations.
d. If and when an appropriate and
adequate land treatment-specific back
calculation model and database can be
developed, the Agency will review
screening concentrations for land
treatment made previously, usteg the
generic land disposal model, and may
%jnake;abpropriate modifications based
on the land treatment-specific back
calculation model and data base.
2. Background
Land treatment of hazardous waste
involves the application of waste on the
soil surface or incorporation of waste
into the upper layers of the soil (zone of
incorporation) in order to degrade,
transform, or immobilize hazardous
constituents present in the waste. As
such, land treatment is both a treatment
and a disposal operation.
Because land treatment depends upon
the dynamic physical chemical, and
biological procedures occurring in the
treatment zone for success, it is
especially important that the units be
carefully operated to maintain optimum
degradation and immobilization of
hazardous constituents, and prevent
environmental contamination.
Development of a treatment program
both allows and demands detailed
consideration of a large number of
factors, including:
a. Waste characteristics.
b. Treatment zone characteristics.
c. Climatic conditions.
d. Operating procedures.
The Agency has established
standards for owners and operators of
hazardous waste land treatment units
under 40 CFR Part 264 Subpart M, and
40 CFR Part 265, Subpart M,
respectively. Many of the regulatory
requirements for hazardous waste land
treatment {HWLT) units are similar to
those for other surface land disposal
units (e.g., requirements regarding-.
Control of run-on and runoff, waste
analysis, recordkeeping, ground water
monitoring^ control of wind dispersal of
particulate matter). However, there are
also significant differences m regulatory
requirements for HWLT units that the
Agency believes should be considered in
developing and implementing the land
treatment restrictions program.
One of the most basic differences is
that land treatment facilities are not
required to have a liner or a cap as are
other surface land disposal units such as
landfills. Neither caps nor liners are
requird for land treatment units because
they would lead to conditions that
would reduce microbial degradation of
hazardous constituents and thus, would
be counterproductive. Similarly, HWLT
units are not required to have a leachate
collection and removal system as is
required for landfills and waste piles.
While land treatment facilities are not
required to have caps or liners, they are
subject to a variety of stringent
regulatory requirements that are not
appHed to any other type of land
. disposal units. Among the more
..: important land treatment-specific
requirements are:
(i) Limitations on the types of waste
that may be treated at HWLT units
(§§ 264.271(a)(l) and 284.272(aJ).
(ii) Specification of operating
practices necessary to maximize the
success of degradation, transformation,
and immobilization processes in the
treatment zone (§ 284.271(a){2)).
(iii) Unsaturated zone monitoring
requirements including soil monitoring
and soil pore liquid monitoring
{§§ 264.271(a)(3) and 264.278).
(iv) Treatment zone limitations (i.e.,
maximum depth of 1.5 meters from the
initial soil surface, and more than 1
meter above the seasonal high water
table (§ 264.271(c)).
(v) Land treatment demonstration
(§264.272).
(vi) Modification of unit operating
practices if results of the uhsaturated
zone monitoring program indicate a
statistically significant increase in
hazardous constituents below the
treatment zone (§ 284.278fg}).
(vii) Expanded recordkeeping
requirements including waste
application dates and rates (§ 284.279).
(viii) Requirement to continue, during
the closure and postclosure phases, all
operations-iiecessary to maximize
degradation, transformations, or
immobilization of hazardous
constituents within the treatment zone
(I 264.280).
3. Proposed Approach for Land
Treatment
The Agency believes that in view of
the many unique aspects of land
treatment, it may not be desirable to
make land treatment restriction
decisions using the same back
calculation models'and data base to be
used for the other land disposal options.
The Agency, therefore, is developing a
model that will represent the chemical,
physical, and biological interactions
between hazardous waste and soil in
the treatment zone. The Agency then
intends to integrate this treatment zone
model with the back calculation models
for air, surface water, and ground water
that will be used for the other land
disposal options, which are described in
Unit III.A of this preamble. The
integrated model will be modified, as
necessary, to make it representative of
land treatment units (e.g., the factors
representing caps and liners will be
eliminated); The integrated model will
be used to establish health-based
concentrations for land treatment
operations.
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Federal Register / Vol. 51. No. 9 / Tuesday. January 14. 1986 / Proposed Rules
Since the statutory restrictions on
land disposal under subsections 3004
(d), (e) and (g) apply to placement in
land-based units incuding land-based
units identified as storage units, (e.g.,
storage surface impoundments and
waste piles), the Agency interprets the
term storage, as used in section 3004(j),
to go beyond the restrictions in
subsections 3004 (d), (e) and (g}.
Therefore, the Agency interprets section
3005(j) to apply to storage that does not
constitute land disposal such as storage
in tanks and containers.
The legislative history indicates that
Congress' concern in enacting this
provision was to foreclose the
possibility of using long-term storage as
a means of avoiding a land disposal
prohibition. (S. Rep. No. 98-264, 98th
Cong., 1st Sess. 18 (1983).) However, in
making the restriction conditional,
Congress did recognize that some
amount of legitimate storage is
necessary prior to final management.
EPA is proposing, under § 268.50, that
generators be allowed to accumulate
prohibited wastes on-site for up to 90
days. EPA has already determined that
this is an appropriate period of time to
allow generators to accumulate wastes
on-site without a permit prior to further
management (40 CFR 262.34). This
period was selected because the Agency
felt that it would allow a reasonable
period for accumulation prior to further
management without interfering with a
generator's production processes, and
because the Agency determined that
most wastes were removed from the site
of generation within 90 days, as
published in the Federal Register of
February 26,1980 (45 FR12730) and
January 11,1982 (47 FR 1248).
The Agency also interprets the
statutory accumulation times of 180 or
270 days for small quantity
generators ia (section 3001(d)(6)) as
representing the allowable time period
for small quantity generators to
accumulate a dufficient quantity of
wastes to facilitate proper treatment
recovery, or disposal. The legislative
history accompanying the small quntity
generator provision states that "the
longer storage period... will allow the
[small quantity] generator to consolidate
wastes into large loads for shipment off
the premises." (S. Rep. No. 98-284,98th
Cong., 1st Sess. 10 (1983).) EPA believes
that Congress, in light of the quntities of
wastes generated by small quantity
generators and the fact that many of
11 See the proposed rule for small quantity
generator? published in the Federal Register of
August 1.1985 (50 FR 31278) for an explanation of
the applicability of these accumulation times.
them are small businesses, recognized
the need for a longer accumulation time.
The Agency has codified these time
periods for generators in todays'
proposed rules by referencing § 262.34.
This was done based on the assumption
that the longer time frames for
accumulation by small quantity
generators will be promulgated as an
amendment to § 262.34 when the rules
proposed for small quantity generators
are issued as final. If this is not the case,
then the reference will be change
accordingly.
While the Agency believes that these
time periods provide a reasonable
accumulation time for most generators,
it is concerned that a longer time may, in
some cases, be necessary to accumulate
sufficient quantities to facilitate proper
recovery, treatment, or disposal. The
Agency solicits comments on the
appropriate time limits for storage of
prohibited wastes by generators to
accumulate sufficient quantities to
facilitate proper recovery, treatment, or
disposal. Specifically, are the existing
accumulation times sufficient or should
procedures be developed for allowing
longer periods on a case-by-case basis?
The Agency does not interpret the
statutory restriction on the storage of
prohibited wastes as overriding the
satellite accumulation rule contained in
40 CFR 262.34(c). That rule allows
generators to accumulate up to 55
gallons of hazardous waste or 1 quart of
acutely hazardous waste hi a container,
at or near the point of generation,
without a permit, interim status, or
compliance with the 90-day
accumulation rule. The purpose of
satellite accumulation is to allow the
accumulation of certain quantities
necessary to facilitate transportation,
further treatment or disposal and, thus,
such'accumulation falls under the
section 3004(j) exemption.
The Agency, believes that transporters
should be allowed to hold prohibited
wastes at transfer facilities for some
minimum period of time to allow for
activities incidental to normal
transporter practices. These activities
may include the consolidation of wastes
into larger units or the transfer of
wastes to different vehicles for
redirecting or rerouting. The Agency is
proposing, under § 268.50, that
transporters be allowed to hold such
wastes for up to 10 days.
The Agency realizes that due to
operational difficulties, repairs and
maintenance at treatment, storage, and
disposal facilities, it may be necessary
for a treatment or recovery process to
shut down temporarily. In. addition,
back-ups may occur at treatment or
recovery facilities while wastes are
being held for treatment or recovery.
The Agency does not believe that it wasl
Congress' intent to ban storage for short]
periods due to these occurrences.
The Agency does not, however, have
data on the frequency of such
occurrences of their usual duration and
is therefore unable to quantify these
time periods. The Agency is proposing
90 days as the maximum time limit on
permissible storage at waste
management facilities under § 268.50
and is seeking comments as to whether
or not this duration is appropriate.
Another approach to the storage
restriction for both generators and
owners or operators of waste
management facilities is not to specify a|
time limit but rather to incorporate the
statutory language directly into the
regulation. Because no specific limit
would be specified, this approach would]
be difficult to enforce and and would
fail to provide the regulated community
with a clear indication of its
responsibilities.
The Agency interprets the statute as
not applying the restriction on storage of
prohibited wastes to successful
petitioners under section 3004 (d), (e),
and (g) and successful applicants for a
case-bay-case extension. The applicant
or petitioner must, however, store his
waste according to the applicable
requirements of 40 CFR Parts 262, 264,
and 265. However, the Agency does
interpret this provision as prohibiting
storage (other than storage necessary to |
generate sufficient quantities to
facilitate proper treatment, recovery, or
disposal) pending the Agency's -
determination on a petition submitted
under sectioni3004 (d), (e), or (g). In
addition, the Agency believes that this
provision does prohibit such storage of a|
waste after the effective date of a ban
pending an Agency determination on an
application for a case-by-case effective
date extension.
IV. Unit-Specific Considerations
Land treatment and deep well
injection are significantly different from
other methods of land disposal of
hazardous waste from both technical
and regulatory perspectives. The
Agency believes that the unique aspects
of these technologies should be
considered in developing regulations for
these land disposal methods under
section 3004 (d), (e), (f), and (g) of RCRA. |
This unit of the preamble summarizes
briefly the unique technical and
regulatory aspects of land treatment.
outlines the Agency's thinking to date on |
how to address this method of land
disposal, and solicits comments and
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Fetfeai RBgfeter / Vol. 51, Wo; 9 /.Taesday. January 14t
1986 / Proposed Rules-
recovery of these spent solvents and
spent solvent mixtures.
F002—The following spent
halogenated solvents:
tetrachloroethylene, methylene chloride,
tnchloroethylene, 1.1,1-trichloroethane,
chlorobenzene, l,l,2-trichloro-l,2,2-
trifluoroethane, ortho-dichlorobenzene,
and trichlorofluoromethane; all spent
solvent mixtures/blends containing.
before use, a total of 10 percent or more
(by volume) of one or more of the above
halogenated solvents or those solvents
listed in F001, F004, and F005; and still
bottoms from the recovery of these
spent solvents and spent solvent
mixtures.
F003—The following spent noiv
halogenated solvents: xylene, acetone,
ethyl acetate, ethyl benzene, ethyl ether,
methyl isobutyl ketone, n-butyl alcohol,
cyclohexanone, and methanofc all spent
solvent mixtures/blends containing
solely the above spent non-halogenated
solvents; and all spent solvent mixtures/
blends containing, before use, one or
more of the above non-halogenated
solvents, and a total of ten percent or
more (by volume) of one or more of
those solvents listed in FOOT, F002, F004,
and F005; and still bottoms from the
recovery of these spent solvents and
spent solvent mixtures.
F004—The following spent non-
halogenated solvents: cresols and
cresylic acid, and nitrobenzene; all
spent solvent mixtures/blends
containing, before use, a total of 10
percent or more (by volume) of one or
more of the above non-halogenated
solvents or those solvents listed in FOOT,
F002, and F005; and still bottoms from
the recovery of these spent solvents and
spent solvent mixtures.
F005—The following non-halogenated
solvents: toluene, methyl ethyl ketone.
carbon disulfide, isobutanol, and
pyridine; all spent solvent mixtures/
blends containing, before use, a total of
10 percent or more (by volume) of one or
more of \he above non-halogenated
solvents or those solvents listed in FOOT,
F002, and F004; and still bottoms from
the recovery of these spent solvents and
spent solvent mixtures.
P022—carbon disulfide
U002—acetone
U031—n butyl alcohol
U037—chlorobenzene
U052—cresols and cresylic acid
UC57—cyclohexanone
U070—o -dichlorobenzene
U080—methylene chloride
U112—ethyl acetate
U117—ethyl ether
U121—trichlorofluoromethane
U140—isobntanol
U154—methanol
U159—•methyl ethyl ketone
^.,1^61—methyl isobutyl ketone
'* U169^hitrobenzene ''
U196—pyridine
U210—tetrachloroethylene
U211—cacbon tetrachloride
U220—toluene
13226—1,1,1-trichloroethane
U228—trichloroethylene
U239—xylene
The legislative history to the 1984
Amendments to RCRA indicates that a
waste may be restricted from land
disposal not only on the basis of
hazards posed by its inherent toxicity,
but also becuase of its ability to degrade
clay and synthetic liner? and to mobilize
relatively non-mobile hazardous
constituents, when co-disposed with
other hazardous waste (S. Kept No. 98-
284, 98th Cong^ 1st Sess. 14 (1983)).
Since solvents exhibit these
characteristics, the Agency has
considered these overriding factors in
developing treatment standards for
solvents.
The Agency is proposing in today's
action to set screening levels for the
individual solvents listed for "toxiciry"
(i.e., FOOT, F002. F004. F005. and the
corresponding P and U wastes). The
Agency is also prospoing a liner
protection threshold which is derived for
the lowest concentration at which
solvents are known to degrade liners. In
cases where screening levels for the
individual solvents exceed the liner
protection threshold, the Agency will
specify the liner protection threshold in
lieu of die screening level. Thus, the
liner protection threshold serves as a
"safety cap" where screening levels are
not stringent enough to assure mat
solvents will not breech liners during the
operating life of the facility.
The Agency also is proposing the liner
protection threshold in heu of a
screening level for ignitable solvents
(F003). These solvents were listed as
hazardous wastes solely becuase they
exhibit the characteristic of ignitability
("toxicity" was not a basis for listing).
Therefore, the Agency was not
evaluated lexicological data for these
solvents.
EPA has determined that a number of
technologies are applicable to the
treatment/recovery of solvent wastes,
including biological degradation, steam
stripping, carbon absorption, distillation.
incineration, and fuel substitution. The
Agency is proposing to identify "best
demonstrated available" technologies
for each solvent waste based upon the
wastes' physical form, the specific
solvent constituents they contain, and
the concentrations at which such
constituents are present. For all solvent
wastes subject to today's proposed
£. rulemaking, best demonstrated
treatment technologies are identified
that are capable of achieving the
screening levels for the applicable
solvent constituents they contain.
Furthermore, although final evaluations
have not yet been completed.
preliminary results indicate that these
best demonstrated treatment
technologies do not pose total risks to
human health and the environment
greater than those posed in the direct ~
land disposal of most categories of the
solvent wastes subject to today's
proposed rulemaking.
Accordingly, EPA is proposing the
screening or liner protection thresholds
as the section 3004(m) treatment
standards for each applicable solvent
constituent contained in the solvent
wastes subject to today's proposed
rulemaking, capping off the required
technology performance levels at these
protective levels.
EPA is proposing to establish
immediate effective dates for all but
three of the categories of solvent wastes
subject to today's proposed rulemaking:
Solvent-water mixtures (wastewaters)
containing less than 1 percent (10,000
ppm) of total organic constituents and
less than 1 percent (10,000 ppm) of total
solids; inorganic sludges and solids
containing less than 1 percent (10,000
ppm) total organic constitutents;
solvent-contaminated soils. The Agency
is proposing 2-year national variances
for these solvent wastes upon a
determination that the capacities of
alternative treatment technologies
capable of achieving the treatment
standards for these wastes (wastewater
treatment units and incinerators), in
conjunction with the capacities of
alternative recovery and disposal
technologies, are insufficient to
accommodate the quantities of these
solvent wastes currently managed in
land disposal units.
2. Description of the Solvent Listings
On May 19,1980, (45 FR 33119), the
Agency listed 27 commonly used organic
solvents as hazardous wastes when
spent or discarded. The solvents were
listed as Hazardous Waste Nos. F001,
F002, FOOT, F004, and F005. The listed
solvents consist of certain spent
halogenated and non-halogenated
solvents, and still bottoms from the
recovery of these solvents. A solvent is
considered "spent" when it has been
used and is no longer fit for use without
being regenerated, reclaimed, or
otherwise reprocessed. Manufacturing
process wastes containing these
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Federal Register / Vol. 51, No. 9 / Tuesday, January 14, 1986 / Proposed Rules
The Agency realizes that it will be
very difficult to develop a land
treatment model and'database due to
the complex interactions between
wastes and the treatment zone/
saturated zone, and the interdependence
of input parameters, For example, the
biodegradation rate for a given
hazardous constituent may vary greatly,
depending upon a large number of
factors, including: Waste constituent
structure, presence of other waste
constituents, waste loading rate, degree
of waste and soil mixing, and soil
characteristics. In turn, many of these
factors may depend upon other factors
and/or vary greatly.
The Agency believes that the complex
interdependence and interactions of
these variables, coupled with the current
limited knowledge of ranges and
distributions of values of some critical
input parameters (e.g., biodegradation
rates) will make the modeling effort very
difficult at-best. Although the Agency
intends to continue developing the land
treatment back calculation model and
database, it recognizes the possibility
that the ultimate conclusion of the
development effort may be that
development of an adequate,
representative model or database is not
feasible and that any special
consideration of land treatment should
be made on a site-specific basis through
the petition process. The Agency will
not be prepared to make a decision on
the feasibility of developing the land
treatment model and database until
considerably more information is made
available by ongoing research efforts
and data requests.
The Agency is concerned that even •
under the most optimistic scenario (i.e.,
the Agency can successfully develop a
representative land treatment model
and database), it is quite likely that a *
land treatment-specific model and
database will not be available in time to
make prohibition determinations for
solvents and dioxins within the 24-
months statutory deadline established
under section 3004(e) of RCRA. In such
an event the Agency proposes to apply
the screening concentration established
for other types of land disposal units to
land treatment operations. When the
land treatment-specific model and
database become available, the Agency
will make necessary modifications, if
any, to the screening concentrations for
land treatment. The Agency believes .
that this is the most reasonable
approach for several reasons. First, it
will allow the Agency to develop the
necessary model and database while
meeting all of the statutory deadlines.
Second, the Agency believes that use of
the screening concentrations calculated
for other types of units will be protective
of human health and the environment
pending development of land treatment
screening concentrations; the Agency
believes that the screening
concentrations for land treatment will
be higher than those established for
landfills. Third, the Agency believes that
the impact on industry of temporarily
using tiie expectedly more stringent
landfill screening concentration will be
minimal, because little if any of the
listed solvent-or dioxin-containing
wastes identified in section 3004(e) are
land treated.
4. Request for Comments and
Information
i
EPA solicits comments on all aspects
of its approach to HWLT and requests
information that may be useful in
implementing the Agency's proposed
plans.
Issues on which EPA would like to
receive comments include:
a. Is a "generic" land treatment model
appropriate for making restriction
decisions on land treatment of
hazardous waste? Or is land treatment
so dependent on waste characteristics,
site characteristics, and facility
operating practices that development of
a representative model is not feasible?
b. If a generic land treatment model is
used, how should the Agency address
variability in waste characteristics, site
characteristics and facility operating
practices?
c. Are critical data (e.g.,
biodegradation rates for hazardous
constituents) adequate and available for
making restriction decisions using a
land treatment model?
d. What timeframe should be used for
the analysis? Should the analysis be
limited to the active closure and post-
closure phases of operation, or should it
extend beyond the post-closure phase?
The Agency also requests data and
other additional information that would
be useful in making land treatment
determinations, including:
(i) Chemical and physical
characteristics of. wastes at land
treatment facilities (e.g., physical form,
types and concentrations of chemical .
constituents, RCRA identification codes,
waste volume).
(ii) Information on land treatment
design and operating measures (e.g.,
methods, rates and timing of waste
application, pH adjustment, nutrient
addition, use of tilling). '
(iii) Biodegradation rates for
hazardous wastes and hazardous
constituents.
(iv) Site characteristics (e.g., soil
characteristics, topography, climate).
V. Proposed Treatment Standards for
Hazardous Wastes Containing Solvents
A. Background
1. Summary of Congressional
Mandate—Land Disposal Restrictions of |
Solvents
According to the provisions in the
1984 Amendments to RCRA, effective 24 |
months after the date of enactment,
furtherland disposal of solvents is
prohibited unless the EPA determines
that such prohibition is not required in
order to protect human health and the
environment. If the Agency fails to meet
this deadline, these wastes will be
banned automatically from further land
disposal. Solvents are presumed banned
unless the Agency sets treatment levels
or persons generating these wastes
successfully demonstrate that "no
migration" will occur from the disposal
unit.
The statute specifically addresses the
list of spent solvents in 40 CFR 261.31—
EPA Hazardous Waste Nos. F001, F002,
F003, F004, and F005. However, the
Agency also is including the
corresponding solvents listed in 40 CFR
261.33 (e) and (f) (i.e., P022, U002, U031,
U037, U052, U057, U070, U080, U112,
U117, U121, U140, U154, U159, U161,
U169, U196, U210, U211, U220, U226,
U228, and U239). The list of hazardous
wastes identified as "P and U wastes"
applies to the unused portion of
commercial chemical products, off-
specification commercial chemical
products, manufacturing intermediates
and spill residues which are intended
for disposal. Since these wastes pose
hazards identical to the corresponding
spent solvents (listed in F001 through
F005), the Agency believes that
Congress also intended to prohibit
further land disposal of these wastes
within the 24-month timeframe.
The Agency in today's action is
proposing treatment standards for the
following spent solvents and
commercial chemical products, off-
specification commercial chemical
products, manufacturing intermediates,
and spill residues:
pool—The following spent
halogenated solvents used in
degreasing: tetrachloroethylene,
trichloroethylene, methylene chloride,
1,1,1-trichloroethane, carbon
tetrachloride, and chlorinated
fiuorocarbons; all spent solvent
mixtures/blends used in degreasing
containing, before use, a total of 10
percent or more (by volume) of one or
more of the above halogenated solvents
or those solvents listed in F002, F004,
and F005; and still bottoms from the
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Federal Register / Vol. 51. No. 9 / Tuesday. January 14. 1986
in landfills, these regulations do not
nave a significant impact on the
, quantities of solvents being land
disposed. The majority of spent solvents
destined for land disposal typically have
been solids or sludges. Moreover, liquid
solvent wastes are typically disposed of
in surface impoundments and, therefore,
are not subject to the prohibition for
liquid wastes in landfills.
D. EPA Concerns With the Land
Disposal of Solvents
1. Adverse Health Effects
When EPA promulgated the first
phase of the hazardous waste
regulations in 1981. solvents were listed
because of their inherent toxicity (and .
igni lability). Many of these solvents are
known carcinogens, teratogens, -
mutagens, or neurotoxins. Others are
associated with acute and chronic
adverse health effects such as kidney.
liver and lung damage (Refs. 100 and
111). Since solvents are mobile and
persist in the environment, the Agency
is concerned that, when land disposed,
these solvents may readily migrate to
ground water. In addition, since some
solvents are highly volatile, the Agency
is also concerned that toxic vapors from
these waste may result in human health
hazards during handling and land
disposal.
2. Solvent/Liner Interactions
-Currently available information
indicates that exposure to dilute
aqueous solutions of solvents could
result in deterioration of flexible
membrane liners. Diluted solvents
appear to have little effect on
compacted soil liners in short-term
exposure tests. There is not, however.
sufficient information available to
predict the effect on soil liners from
long-term exposure to dilute solutions.
Additional research is needed not only
on possible long-term effects of dilute
solutions, but also on mechanisms by. -•
which concentrated solvent phases may:
be generated in landfills or surface
impoundments.
a. Interactions betweea^SoJvents and
flexible membrane Kners[FMLs), There -
are a variety of mechanisms by which
solvents can interact with FMLs. In-- —
general, most FMLs will adsorb..
solvents, which can result in swelling
and decreased physical strength in the
liner material (Ret 54). Additionally,
solvents can leach plastieizers out of.
certain types of FMLs, causing the liner
material to shrink and become brittle
"(Ref. 56}. .
One possible mechanism by which
solvents may interact with synthetic
liners involves the solubility parameter
theory; This theory was developed
originally for predicting the behavior of
• simple liquids in solution. .Recently, ';:
however, the solubility parameter theory
has been extended to the behavior of
complex liquids in solution, the behavior
of. liquid mixtures, and the behavior of
polymers (such as those found in
synthetic liners). The basic assumption
behind the theory is that any given
molecule will be attracted to any other
molecule provided that they exhibit
similar physical and chemical factors.
such as cohesive energy density,
hydrogen bonding and polar bonding.
-The physical and chemical factors of a
liquid or polymer are analyzed and
weighted to determine the total
solubility parameter. The total solubility
parameters for liquid mixtures or
solutions is determined by adding up the
individual parameters for each
component, weighted by their volume
fraction in solution. Thus, the solubility
parameter for a dilute solvent solution
equals the parameter for that solvent
(weighted by its volume in the solution)
and for water (weighted by its volume in
the solution) (Ref. 90).
Liquids, solutions or polymers with
like solubility parameters will be
attracted to one another. Thus, wastes
with total solubility parameters similar
to those of a polymer used to fabricate
an FftfL may adsorb into the liner
causing the liner to dissolve or swell
and. therefore, potentially fail.
Barton and Burrell (Refs. 20, 21, and
31) provide comprehensive tabulations
of solubility parameters for common
solvents and polymers. Almost all
individual solvents contained in FOOl
through F005 and the polymers used to
fabricate FMLs fall within a solubility
parameter range of 7.4 to 10.7 cal/cm*
(Refs. 56 and 95). Consequently, when
these polymers come into contact with
waste liquids containing solvents or
solvent mixtures, at any concentration,
sweHing-or dissolution of the polymer te
likely ta occur.
H8xo (Ref. 53) indicated that swelling
of an PML is associated with
deterioration in the FMLs' physical
properties (i.e.. loss of mechanical
strength, softening, increased -
permeability, tendency to creep, etc.). In
a recent study, Haxo et al. (Ref. 56) -
examined the swelling of 12 FML»
submergedrrn-aflerieaof nine pure-
solvents with different solubility
parameters (6.8to 14.5). All the FML* -
showed significant swelling after
exposure to most of the- solvents. It '
should be noted that even without
showing much swelling, FML properties,
such as tear resistance, puncture
resistance, gain in permeability, tensile
strength, and propensity to undergo
stress-cracking, can be affected by
solvents (Ref. 56).
There are few data available on the
impact of dilute solvents on the physical
properties of FMLs. However, in one
study. 12 FMLs were exposed for 500
days to a dilute aqueous solution of a
solvent (Ref. 55). The data indicated that
even very low concentrations of
solvents may deteriorate FMLs.
A study conducted by the Federal
Environmental Agency of Germany (Ref.
18) tested 13 solvents, both in their
dilute and pure form, against 14 FMLs of
various types and thicknesses. Two of
the test solvents, xylene and toluene,
permeated through the FMLs at faster
rates than would be expected. A
solution of 200 ppm xylene mixed in
water permeated through a high density
polyethylene liner sample at a rate of 1.6
gm/m2/day, while a solution of 500 ppm
toluene permeated through a high
density polyethylene liner sample at a
rate of 2.0 gm/m2/day. These rates are
only 10 to 50 times lower than the rates
of the pure solvents (Ref. 18).
Solvents, are also known to diffuse
through FMLs. Lord et al. (Ref. 71)
reported that benzene diffused through
ethylene propylene diene rubber,
polyvinyl chloride, and chlorinated
polyethylene at the rate of 2X10~S,
1.3X10-6, and 8XWT7cmVsec,
respectively. Diffusion coefficients of
this magnitude would allow benzene to
pass through a 30 mil sheet of these
materials in about 2 years if the initial
concentration was as little as 100 ppm.
There are no data available on the
effect of solvent mixtures on FMLs. In
addition, these mixed solvent effects
cannot always be predicted on the basis
of solubility parameters (Ref. 95). There
are cases where a polymer that was
insoluble in individual solvents was
quite soluble when these solvents were
mixed (Ref. 74).
Solvent wastes are often complex
mixtures of solvents. Several FML
experts have suggested that no single
FML is likely to be resistant to the
complete range of solvents {Refs. 53 and
96). Complex mixtures of solvents will,
therefore, increase the probability that
at least one component of the solvent
mixture will adversely affect the
physical properties of an FML
b. Interactions between solvents and
compacted soil liners. Several studies
have shewn that concentrated solvents
with-properties similar
-------
Federal Begbto / Vol 51..N-. 9 / Tuesday, January 14. 1986 / Proposed Rales
solvents are not covered under the
listing.
When the Agency promulgated the
solvent listings, a major regulatory
loophole was created by the manner in
which the listing were originally
structured—that is, only the pure form of
the solvents or technical grade were
covered by the listing. Therefore, the
Agency amended the listing to include
mixtures containing a total of 10 percent
or more (by volume) of one or more of
the listed solvents, as published in the
Federal Register of December 31,1985
(50 FR 53315).
The Agency also listed as hazardous
waste certain commercial chemical
products, manufacturing chemical
intermediates or off-specification
commercial chemical products (under 40
CFR 261.33(e) and (f)). Commercial
chemical products and manufacturing
chemical intermediates are defined as
chemical substances which are
manufactured or formulated for
commercial or manufacturing use, and
which consist of the commercially pure
grade of the chemical, any technical
grades of the chemical that are produced
or marketed, and all formulations in
which the chemical is the sole active
ingredient. Section 261.33 also lists as
hazardous wastes off-specification
variants and the residues and debris
from the cleanup of spills of these
chemicals. Finally, certain containers
that have held these chemicals also are
hazardous wastes under §261.7.
B. Physical and Chemical
Characteristics of Solvents
Large volumes of solvents are used in
a variety of industries because of their
inherent ability to dissolve and mobilize
other constituents. For example,
solvents are used in dry cleaning, vapor
degreasing, and cold cleaning of metals
and parts: extraction of oils and waxes;
in solvent drying; and dye
manufacturing. Solvents also are used
as extractants, diluents, and chemical
intermediates. When land disposed, the
ability of solvents to dissolve and
mobilize other constituents may cause
adverse effects such as degradation of
liners, mobilization of co-disposed
wastes, air emissions, and ground water
contamination. The characteristics of
solvents can be quantified using
physical and chemical parameters such
as solubility, vapor pressure and liquid
density. In addition, biodegradation,
bioaccumulation, oxidation, hydrolysis,
and photodegradation indicate whether
solvents are likely to persist in the
environment once they have migrated
from the land disposal unit Two of
these parameters, solubility and vapor
pressure, are discussed in today's
action. The other parameter* are
addressed fa the Background Document
for solvents to support this proposed
rule (Ref. 4).
1. Solubility
Solubility is a measure of the mass of
a substance that has disssolved in or
become miscible with water at a given
temperature and pressure. When applies
to solvents, this measure may be used as
an indication of which solvents are more
likely to enter into the aqueous phase
and how fast they would enter that
phase. Solvents that possess high
solubility values will enter into the
aqueous phase more readily than
solvents with low solubility values.
Hence, solubility may be used to
indicate the potential of a solvent to
migrate into and remain with the ground
water beneath a land disposal facility
(Ref. 95).
In general, many of the halogenated
solvents are less soluble than the non-
halogenated solvents. Solvents, such as
chlorobenzene, carbon tetrachlodde,
tetrachloroethylene, and o-
dichlorobenzene have low solubilities,
while non-halogenated solvents, such as
pyridine, methyl ethyl ketone, and
isobutanol have very high solubilities
(Ref. 95). Despite their low solubilities,
halogenated solvents have been found
in ground water, well water, and surface
water. Anderson and Jones (Ref. 15)
reported that both halogenated and non-
halogenated solvents were found as
contaminants in drinking water wells
and in surface water. A study of 50
industrial waste land disposal sites
demonstrated that in 80 percent of the
sites, ground water was. contaminated
with halogenated organics (Ref. 33)-
2. Vapor Pressure
Vapor pressure is the pressure which
is exerted by a gas at equilibrium with
its solid and liquid states at a given
temperature. A solvent's vapor pressure
may be used as an indication of its
volatility. The higher the vapor pressure,
the greater the tendency of a solvent to
volatilize. Solvents with high vapor
pressures may present a substantial risk
from air emissions when placed in open
disposal areas, i.e., surface
impoundments and land treatment (Ref.
100). Coupled with low solubilities,
these solvents readily volatilize. For
example, solvents with high vapor
pressures and low solubilities, such as
trichlorofraoromethane, carbon
disulfide, 14.2-Mcholoro-lA2-
trifluoroethane, and carbon
tetrachloride, are more likely to
volatilize into the atmosphere rather
than remain in the disposal unit.
C. Characterization ofSofrent Wastes
1. Solvent Waste Characteristics
Spend solvents typically are sludges,
wastewaters, and liquids. Residues f
treatment of these wastes consists of
still bottoms, incinerator ash,
wastewaters, and, in some cases,
stabilized or solidified wastes. The
majority of spent solvent wates,
however, are liquids or sludges. Of the
listed spent solvent wastes disposed in
1981, the greatest quantities were
inorganic liquids, organic liquids, and
inorganic sludges (Ref. 41).
Spent solvent wastes may vary in
composition. For example, these wastes |
may contain contaminants, such as
chemicals, inorganic materials, organic
materials, sorbents, dirt, ash, metals,
and water. In addition the waste's
actual solvent content varies from wast
to waste. Liquid solvent waste can
contain up to 90 percent of the original
solvent. A solvent sludge waste may
contain between 10 and 50 percent of
the original solvent Incineration ash, on|
the other hand, generally contains
solvents only in the parts per billion
range.
Solvents listed under 40 CFR 281.33(e)|
and (f] are the unused portions of
commercial chemical products,
manufacturing chemical intermediates,
or off-specification commercial chemical]
products that are intended to be
discarded. These wastes may be liquids
or solids. Certain containers or inner
liners removed from a container that has|
been used to held a commercial
chemical product or manufacturing
chemical intermediate and any residue
or contaminated soil, water, or other
debris resulting from the cleanup of a
spill also are covered by the listing.
2. Quantity of Solvents Currently Land
Disposed
Approximately 3.1 billion gallons of
spent solvent waste were generated in
1981 (Ref. 9). This includes the solvents
covered in today's proposal The
following quantities were land disposed
in 1981:
[In muttons of gallons!
Actrnty
Large quantity generators:
lantl dBSpotocJ
Landfill „ •_
Surface impoundment. -
' Waste piles ..
Land «pplfc«*(m
Small quantty generators: Land ditpoMd
Volume
M aoa
32
• 1,169
0.743
0.001
7.8
1 Excluding deepwell injection.
' Inducing treatment and storage surface impoundments. |
Although EPA has promulgated
regulations restricting disposal of liquids I
-------
1716
Federal Roghto / Voh 51, No. 9 / Tuesday: fan..*™ 14i 1S86
expected that solvents with equal or
esser solubility also will aot-affect
teachability of other constituents.
In light of the limited data available
on mobilization power of solvents, in
particular, whether solvents present in
concentrations at or below the liner
protection threshold will mobilize other
constituents, the Agency is initiating
further studies. When additional data
becomes available, the Agency will re-
evaluate the liner protection threshold.
In the interim, however, the Agency is
requesting comments and data on this
issue.
4. Volatilization of Solvents From Land
Disposal Sites
Many solvents are highly volatile. As
such, these solvents are likely to escape
into the atmosphere. In particular,
solvents with high vapor pressure and
low solubilities (such as
chlorofluorocarbons, carbon disulfide
and carbon tetrachloride) will volatilize
rather than remain in the disposal unit.
The Agency is concerned that these
toxic solvents when airborne may pose
adverse effects to humans and animals.
Also, certain solvents such as
chlorofluorocarbons are known to pose
environmental harm (i.e., depletion of
the ozone layer).
The California Air Resources Board
(ARE) conducted a study designed to
measure the escape of volatile organics
from land disposal areas. The study
showed that high levels of hydrocarbons
f /were being emitted from major -
hazardous waste disposal sites. The
levels detected, in some cases, were
several orders of magnitude higher than
the National Ambient Air Quality
Standard for hydrocarbon emissions.
From the results of the study, ARB
concluded that current land disposal
practices do not adequately prevent the
air emissions of certain organic
compounds, but instead allow
substantial emissions of tirese
compounds (Ref. 4).
The Agency believes that the
treatment standards proposed in today's
action will substantially reduce air
emissions due to the land disposal
solvent wastes. However, as discussed
earlier, the Agency is developing a back
calculation procedure to assess the
effects of air emissions. The Agency's
plans for that procedure, as well as that
procedure's effect on the treatment
standards being proposed today, are
discussed in Unit III.A.4.
5. Contamination of Soil and Ground
Water Solvent
Contamination of soil and ground
water has occurred at several landfill
sites. In Wilsonville, Illinois, a
hazardous waste landfill was found to
be leaking. Concentrations of
halogenated organics as high as 36
TABLE 10—HEALTH-BASED THRESHOLDS
percent were found in monitoring wells
9 feet from the site (Ref. 93).
These data clearly demonstrate that
solvents may migrate from landfills to
surrounding soils and ground water
where they may cause harm to humans
and the environment.
E. Screening Levels/Liner Protection
Threshold
Since solvents are known to degrade
clay and synthetic liners and to mobilize
other hazardous constituents when co-
disposed with hazardous wastes, the
Agency cannot be assured that
screening levels, based on toxicity
concerns are protective of human health
and the environment. Therefore, the
Agency has developed a liner protection
threshold which takes into account the
effects of solvents on liners.
1. Applicability of Screening Levels
The Agency has derived screening
levels for the solvents listed on the basis
of toxicity using the ground water back
calculation model. In calculating these
levels, the Agency used the apportioned
RfD for noncarcinogens, or MCL or RSD
(1(T *) for carcinogens as the starting
point.
The Agency has developed the
following health-based thresholds for
constituents in solvents wastes in the
following Table 10:
— -•- —
Solvent
Acetone
n-Butyf Alcohol
Carbon Disulfide
Carbon Tetrachlonde
Cresors (p. m. o) "
Cyclohexanone
ortho-Dichlorobenzene.
Ethyl Acetate
Ethyl Benzene '
Ethyl Ether
Isobutanot
Methanol
Melhyiene Chloride
Methyl Ethyl Ketone
Methyl Isobutyl Ketone
Nitrobenzene...
Pyridine
Tetrachloroethylene ... ™" ~"
Toluene .
1 , 1 ,1 -Tnchloroethane ....
1.1.2Trk^oro-1,2,2Trifluoroetna™.".'.".".'.'.'
Trichloroethylene
Tnchlorolluoromethane .
' F003 ignHable only solvents.
•• ffi?toSiE^Jff?siia^a
• -
Waste code (F.p&u)
F003. U002
F003. U031 :
F005, P022
FOOL U211
F002. U037
F004, U052
F003. U057
F002, U070...
F003. U112
F003_.»
F003.U117
POOS. Ut40._. .
FOOSi U154. ..
FOOL F002, U080
F005, U1S9._ „..
F003;U16t
=004v U169
rOOS. U196.
=001. F002. U210
:005. U220-..
FOOL F002. U226
F002 „ •
:001. F002. U228
:002.U121
'•003, U239
—
>sylie Add
Reference
dose (mg/1)
3.85
"0.005
0.95
'1.8
0.015
3.15
11.0
•0.056
1.6
0.016
0.075
•6.6x10^'
10.0
•0.2
950.0
•0.005
12.2
Percent
fractionated to
water
25
10
40
10
*
25
25
25
40
10
10
Fractionated
reference
dose
t.O
O.I
'0.7
0.3
2.75
0.4
0.004
0.03
95.0
Hydrolysis (constant/hr.)
None
None
>10y*...
>7000y-
None ;
None
4.0E-1"; 396«_
None _
None _.
None
None ;.
1.1E-8-
Mono...;..
Mono
stone
Mone
None
None
267D1
>ioy« ; '
None...
tone
-0.24
'0.88
'2.16
2.96
2.87
2.15
'0.81
3.58
0.66
'0.73
3.36
0.71
0.74
-0.75
1.26
0.30
1.25
1.90
0.68
3.03
2.82
2.50
3.10
2.28
2.52
'3.15
Screening
level (mg/1)
220
0.1
2.0
' 15.0
6.5
60.0
1.2
8.8
0.09
0.7
0.015
22.0
1,300.0
•320.0
0.1
66.0
nated)
* Base Hydrolysis.
• Neutral Hydrolysis.
' Data Undergoing Verification
' Based on surface water screening procedure
-------
Federal Kagigtor / VoL 51. No. 9 / Tuesday, January 14, 1986 / Proposed Rules
dielectric constant of these concentrated
solvents which is associated with the
permeability increases (Refs. 29 and 75).
The high dielectric constant of water
causes the expanded clay minerals to
swell and disperse. In the context of a
compacted soil liner, clay mineral
swelling and dispersal tends to decrease
the effective diameter of soil pores, and
thereby decrease permeability of the
liner. If subsequently exposed to
solvents with dielectric constants of less
than 50, the clay minerals will tend to
flocculate (Ref. 29). When the clay
minerals in a soil liner flocculate, the
soil liner will begin to shrink, crack, and
exhibit large increases in permeability.
All of the solvents in FOOl through F005
have dielectric constants of 36 or less
(Refs. 14, 57, and 95). Consequently, if
any of these undiluted solvents is placed
in soil-lined land disposal facilities, the
permeability of the soil liner may be
greatly increased.
The effect of aqueous solutions
containing solvents on the permeability
of soil liners has been shown to be
related to the concentration of the
solvents. Brown and Thomas (Ref. 29)
found that the permeability of soil liners
increased when the concentration of
solvent in water was sufficient to
decrease the dielectric constant of the
solution below 50 (the dielectric
constant of water equals 78.5). For the
solvents in FOOl through F005, there
would need to be a solvent
concentration in water of at least
several percent before the mixture
would have a dielectric constant of less
than 50. However, few of the solvents in
FOOl through F005 are soluble in water
at concentrations greater than a few
percent. These solvents will separate
from water and form a concentrated
solvent phase. Therefore, an aqueous
solution containing FOOl through F005
solvents may yield a concentrated
solvent which may adversely affect a '
soil liner provided that the solution has
a dielectric constant less than 50..
The ability for concentrated solvents
to migrate rapidly through clay soils and
compacted soil liners has been verified
in field-scale studies using solvent
wastes (Ref. 27) and. at hazardous waste
disposal facilities where solvents have
been disposed (Ref. 50). Dilute solutions
of solvents appear to have little effect
on soil liners in short-term tests (Ref.
37). Brown et al., (Ref. 28) tested the
effect of 100.75, 50.25,12.5, and 2
percent acetone diluted with water on a
compacted micaceous soil. The results
showed an increase in permeability of
the soil when the acetone concentration
in the solution was greater than 50
percent; however, the dilute solutions of
less than 50 percent acetone showed no
increase in permeability of the soil.
Brown theorized that at the low acetone
concentrations the solution may have
caused dispersion and swelling of the
clay which would be more likely to lead
to a decrease in permeability rather than
an increase. The higher concentration of
acetone, however, may have caused
flocculation and shrinkage of the clay
resulting in an increase in permeability.
Although this study showed little
adverse effects from a low
concentration solvent on a soil liner, it is
possible that in the long-term the solvent
eventually may cause an increase in
permeability. Overall, little is known
about the long-term effects of dilute
solvents on the permeability of soil
liners.
Several mechanisms have been
suggested by which concentrated "
solvent phases may be generated after a
solvent-bearing waste has been placed
in a landfill, as follows:
i. Waste solids may biodegrade, losing
the ability to retain solvents (Ref. 17),
ii. Solvents may be displaced or
washed from waste solids or sorbents
by water percolating through the landfill
(Ref. 14).
iii. Waste solids may release solvents
in response to gravitational forces (Ref.
17).
iv. Solvents may be squeezed out as
waste solids consolidate due to
overburden pressures (Ref. 17).
v. Solvents may be separated from
water due to decreases in their
solubility inducted by changes in the
temperature and/or ionic strength of the
aqueous solution. •
vi. Solvents may volitalize from water
and condense elsewhere, forming more
concentrated solutions.
vii. Percolation of solvent-water
mixtures through waste solids may tend-
to concentrate one phase through either
molecular sieving or preferential
adsorption.
There are many methods used in
organic chemistry to separate liquid
phases. Additional research is needed to
determine the extent to which these
methods and the mechanisms discussed
above may result in the formation of
concentrated solvent phases hi landfills
or surface impoundments which may
pose deleterious effects on liner
systems. With the information that is
currently available, it is not possible to
determine the effect of long-term
exposure to dilute solutions of solvents
on soil liners.
3. Mobilization of Other Hazardous
Constituents
Solvents are used in commerce
primarily for their ability to dissolve or
disperse (mobilize) other substances.
For example, studies conducted on 1
contaminated soils demonstrated that
more than 95 percent of the PCBs were
extracted from these soils using acetone 1
as a solvent (Ref. 92). Since solvents are|
known to degrade and in some cases,
permeate both synthetic and clay liners,]
the Agency is concerned that solvents
may readily facilitate migration of other \
non-mobile or relatively immobile
hazardous constituents from the land
disposal unit.
A recent study conducted by the
Agency, supports its claim that solvents
may increase the mobility of other
compounds (Ref. 43). The study
demonstrates that wastes containing
aromatic solvents and chlorinated
solvents, as well as surfactants,
generally increase the mobility of
compounds adsorbed onto a synthetic
waste. Wastes such as electroplating
waste, American Petroleum Institute
separator sludge, lime-stabilized waste
and an unstabilized sludge were used hi \
the study. However, due to the
complexity and diversity of these
wastes some chromatographic
interferences and reproducibitiiy
problems occurred. (The wastes
contained high concentrations of a
variety of solvents.) The Agency
therefore is contemplating doing further
research and applying synthetic waste
using a standard leaching solution with
single solvents or binary mixtures of
common organic solvents added at low
levels. Such a protocol will assure •
homogeneity and allow for stability
testing. Information from the study could|
then be used to assess better and
possibly predict the mobilizing power of |
common organic solvents at low levels.
Although these data clearly indicate
that solvents may mobilize other
hazardous constituents present in land
disposal units, the Agency believes that
the treatment standards (i.e., the health-
based thresholds and liner protection
threshold) are below concentrations
which may elicit this effect. For
example, the Agency has found that in a
field-model lysimeter test conducted
during development of the TCLP, the
presence of toluene in the range of 1 to 2
parts per million (i.e., the level of the
liner protection threshold) did not
appear to affect significantly the
leaching of organic compounds (see Unit
III.D). Since the treatment standard for
the individual solvents does not exceed
2 ppm, the Agency believes that the data
indicate that solvents at this
concentration will not increase the
leachability of relatively non-mobile
constituents. Moreover, since toluene is
a "strong" solvent, it can reasonably be
-------
1718
KagMtef / Vol. 51, No. 9 / Tueadav. January 14, 1986
proposed rule (Ref, 4} gives a detailed
description of this analysis.
t. Applicable Treatment Technologies
The Agency has evaluated many
treatment and recovery technologies for
their ability to remove, destroy, or
immobilize solvent constituents present
in hazardous wastes. Recovery or
recycling methods (e.g., reclamation and
reuse) are included in this analysis
because these technologies also remove
or destroy hazardous constituents
present in hazardous wastes. Treatment
and recycling technologies potentially
applicable to solvent wastes fall into
three general categories: Separation/
removal techniques such as evaporation,
air stripping, steam stripping,
distillation, carbon adsorption, and resin
adsorption; destruction techniques such
as incineration, use as a fuel substitute,
chemical oxidation and reduction,
biological treatment, and wet air
oxidation; and immobilization
techniques such as encapulation and
chemical fixation/solidification. These
technologies are described below.
Separation/removal techniques are
particularly applicable to many solvent
wastes primarily because of the inherent
volatile nature of many solvents. Since
solvents are usually more volatile than
the other constituents of the waste, they
can often be removed by simple static
evaporation or by passing air over or
through the waste, a process called air
stripping. Vapor pressure or volatility of
prganics increases as the temperature
increases; therefore, the application of
heat or steam, such as the use of steam
stripping, can be used to increase the
rate, and often efficiency, of separation
and to remove solvents of relatively
lower volatility. Distillation processes
are also used to reclaim spent solvents
based on the relative volatility of their
organic constituents. In conclusion, the.
performance of these separation and
removal methods for different solvents
will vary because of the inherent
differences in vapor pressures of the
individual solvents.
Solvents separated thieugksteam
stripping or distillation are typically
recovered by condensation. Carbon
adsorption is often used to capture less
concentrated organic emissions from air
stripping. Steam stripped solvents may
require further treatment via distillation
to purify enough for reuse. Distillation
generates both a reclaimed solvent,
which is reused, and a sludge, which
normally requires further treatment by
the destruction methods addressed
below.
Carbon and resin adsorption are also
separation/removal techniques used
primarily for aqueous wastes. The
solvent constituents are removed by
physical and/or chemical attraction on
the surface of macro- and micro-pores of
the adsorbents as the waste is passed
through it Solvents which have lower
water solubility or higher molecular
weight will generally be adsorbed more
efficiently than those of high water
solubility or low molecular weight. The
spent carbon or resin can be
regenerated, producing a more
concentrated solvent waste, or
subjected to the destruction methods
described below.
Destruction techniques involve the
processes of oxidation and reduction,
which break the chemical bonds within
the solvent molecules to produce smaller
molecules and fewer hazardous
compounds such as carbon dioxide,
water, and hydrogen chloride. These
techniques are applicable to all organic
compounds.
Incineration is the most efficient and
rapid oxidation and destruction
techniques currently available. The
oxidation reaction occurs at elevated
temperatures, in the gaseous state, and
with highly efficient mixing. These
conditions are the most highly
favorable, both kinetically and
thermodynamically, which currently
exist for oxidation. Several other
technologies, such as wet air oxidation,
incorporate variations on these
favorable conditions by either using
even higher temperatures, higher
pressures, or more efficient mixing.
Chemical oxidation and reduction
techniques generally involve the
addition of chemical reagents (i.e.,
oxidants and reductants) to the waste,
at or near ambient temperature and
pressures. Typical reagents include
chlorine, chlorine dioxide, hypochlorite.
ozone, hydrogen peroxide, potassium
permanganate, sodium bisulfite, sodium
borohydride. and sodium or potassium
metal While these reactions can be
quite efficient, they occur at much lower
reaction rates compared to oxidation
rates of incineration and are more
sensitive to interferences and competing
reactions. Data indicate that tiiese rates
can often be improved by application of
low energy through ultraviolet
irradiation, by addition of inorganic
catalysts, and by use of efficient mixing
devices. The oxidation techniques are
primarily applicable to aqueous waste
because of the ease widi which the
reagents can be added and mixed. The
reduction techniques which involve the
addition of sodium or potassium metal
are designed for non-aqueous wastes
because of their reactivity with water
and are designed to strip halogens off of
the halogenated solvents. These
reagents are dangerously reactive and
nave limited application.
Biological treatment accomplishes
destruction via chemical oxidation and
reduction within the cell wallj of
various biota such as bacteria, virus,
fungi, and other microbes. Theoretically,
all of the solvent constituents can be
biodegraded, but many constituents are
toxic to the organisms at even low
levels. All constituents must be present
below toxic concentrations if
biodegradation is to occur. While
biological reactions can be quite
efficient for some wastewaters and
hazardous constituents, they generally
require more lengthy reaction and
contact time than nonbiological
reactions. The biota are generally quite
sensitive to concentrations of other toxic
constituents (e.g., metals such as arsenic
and cadmium). The processes also
require maintenance of nutrient levels,
and removal of spent biomass. It is
necessary to develop the specific
biomass necessary for degradation
through an acclimation process.
Immobilization techniques have been
demonstrated on a limited number of
wastes and have yet to be verified as
practically applicable to all solvent
constituents. Theoretically, any organic
molecule (and, therefore, any solvent)
can be entrapped in an inorganic or
organic matrix and immobilized. This is
the concept of microencapsulation.
However, sufficient amounts of reagents
must be present in order to surround the
molecule completely. Data also indicate
that there may exist a limit on the total
organic content, not just the solvent
content, which can be
microencaps-olated or chemically fixed
in a solid inorganic matrix. The choice
of an organic matrix for
microencapsulation must consider the
solubility of the matrix in the solvent
being encapsulated.
All of the. aforementioned .
technologies appear to have some
applicability to solvent wastes. In the
following unit EPA discusses the extent
of this applicability for the technologies
that are demonstrated.
2. Demonstrated Treatment
Technologies
The Agency evaluated data on the use
of the treatment technologies described
above to treat solvent-containing waste
codes FOOT through F005 as well as P-
and U-listed solvent wastes. Solvent
wastes fall into two general treatability
groups: (1) solvent-water mixtures (i.e.,
wastewaters} or other liquids containing
solvents that are amenable to
separation/removal techniques (e.g.,
steam stripping, carbon adsorption.
-------
Federal Register / Vol. 51, No. 9 / Tuesday, January 14, 198$ / Proposed Rules
2. Derivation of the Liner Protection
Threshold
As described earlier, several studies
demonstrate that solvents degrade
FMLs. Although the data does not show
effects of dilute solvent concentrations
on soil liners, the Agency believes that
these low concentrations may likewise
degrade liners given a longer exposure
time (liner compatibility tests generally
are conducted for only a few months to
a year). Moreover, waste/liner
compatibility tests of incoming solvent
wastes do not take into account possible
waste-to-waste interactions within the
disposal facility. These interactions may
allow a previously compatible solvent to
combine with other solvents (or other
chemicals) and result in a mixture which
can degrade soil liners. Thus, in
developing a liner protection threshold,
the Agency relied on a liner
compatibility study which demonstrates
increased permeability of an FML
exposed over a period of 30 days to a
dilute solution containing 0.02 percent
(200 ppm) xylene and water (Ref. 18).
The Agency believes that the data
represent the lowest concentration at
which solvents are known to degrade
FMLs. The Agency applied the 200 ppm
level as the starting point in calculating
the liner protection threshold. However,
lower concentrations of solvents may
likewise affect liners given sufficient
exposure time. For example,
concentrated solvent phases maybe
generated from these dilute solutions as
a result of volatilization and
condensation, or solvents may be
generated from these dilute solutions
may be squeezed out of solution due to '
pressure within the disposal facility. In
addition, factors such as interactions
with co-disposed wastes, effects of
solvent mixtures, and liner type (i.e.,
high density polyethylene (HDPE),
polyvinyl chloride (PVC), ethylene
propylene rubber (EPDM), chlorinated
polyethylene (PEC), ethylene copolymer
asphalt (ECB)) may also effect
permeability. Additional research is
needed to determine the extent to which
dilute solutions of solvents and solvent
mixtures may affect liners over the long
term.
In light of these uncertainties and data
gaps, the Agency derived the liner
protection threshold by dividing the 200
ppm starting point by an uncertainty
factor of 100. The choice of this factor is
based on extrapolation from short-term
exposure (30 days) to the actual
operating life of the facility combined
with the factors described earlier. The
calculated liner protection threshold is 2
ppm.
The Agency is soliciting comments on
the derivation of the liner protection
threshold. The Agency also is seeking
data on solvent/liner interactions. In
particular, EPA is interested in data
which demonstrate the effects of dilute
solutions and solvent mixtures on FMLs.
3. Applicability, of the Liner Protection
Threshold
a. Toxic solvents. Screening levels are
intended to identify levels at which land
disposal is protective based on a
consideration of the toxic effects of
constituents. However, the Agency is
concerned not only with the toxic effects
of solvents but also, as discussed above,
their effects on liners. Therefore, the
Agency is specifying the liner protection
threshold in lieu of a screening level
where the screening level for an
individual solvent may not be stringent
enough to protect liners during the
operating life of the facility (i.e., the
screening levels exceeds the liner
protection threshold).
The liner protection threshold
overrides the screening levels for the
following toxic solvents:
Carbon disutfide
P-cresol
M-cresol
Ortho-dichkxobenzene
Iscbutanol
Methyl ethyl ketone
1,1.2-!richloro-1,2,2-
Trichlorofluoromethana
Screening
level
220
15.0
150
150
as
60.0
8.8
220
1,3000
320.0
66.0
liner
protection
threshold
20
2.0
20
20
2.0
2.0
2,0
20
2.0
2.0
2.0
The Agency is requesting comments
on all aspects of today's proposal for the
solvents land disposal restriction. In
particular, it is requesting data on the
effects of dilute solvent solutions and
mixtures on clay and synthetic liners
and also data on the ability of solvents
to mobilize other hazardous waste. In
• addition, the Agency is requesting
comments on the liner protection
threshold determination.
b. Ignitable solvents (F003). The F003
solvents were listed solely because they
exhibit the characteristic of ignitability.
Therefore, they are not included in
either Appendix VII or VIII.
At this time, the Agency is evaluating
data which indicate that these solvents
may be toxic. The results of this
evaluation are expected in early
February 1986. If these data support
listing these solvents as "toxic" wastes,
the Agency will add these solvents to
both Appendices VII and VIII, amend
the listings to include these solvents in
the list of ignitable/toxic solvents
(F005), and establish screening levels for
these wastes. Since it is unlikely that
these tasks can be completed within the |
timeframe established for this
rulemaking, the Agency is proposing, in
the interim, to establish the liner
protection threshold as the treatment
standard for ignitable solvents. Once
screening levels are developed for these j
solvents the Agency will re-evaluate
these levels.
Data from delisting petitions
addressed in the solvents restrictions
Background Document (Ref. 4) show that]
treated waste or waste which naturally
meets the 2 ppm threshold will no longer |
exhibit the characteristic of ignitability.
Several liner compatibility studies show
effects on FMLs caused by ignitable
solvents such as acetone, xylene,
methanol and ethyl acetate. For
example, effects were seen at
concentrations of 5.0,0.02, 5.0, and 5.0
percent respectively (Ref. 18). These
solvents have solubility parameters
similar to those of the polymers used to
fabricate FMLs and, therefore, are more
likely to cause liners to swell or
dissolve.. Thus, the Agency believes that
specifying the liner protection threshold
as the treatment standard for ignitable
solvents is appropriate and feasible. The |
Agency is proposing 2 ppm as the
treatment standard for the following
ignitable solvents:
Xylene
Acetone
Ethyl acetate
Ethyl benzene
Ethyl ether
Methyl isobutyl ketone
N-butyl alcohol
Cyclohexanone
Methanol
F. Analysis of Treatment Technologies
for Solvents and Determination of
BOAT
In order to set treatment standards for
solvent wastes subject to this proposed
rulemaking, the Agency must evaluate
the ability of treatment technologies to
remove, destroy, or immobilize the
hazardous constituents that these
wastes contain (see Unit II for an
explanation of setting treatment
standards). Based on its study of
applicable treatment methods, EPA
determines the best demonstrated
achievable technology (or technologies)
for hazardous wastes, and the
performance of these technologies (see
Unit III.C for a discussion of the
procedures to determine BOAT). This
unit summarizes the analysis of
treatment technologies pertinent to
solvent wastes. The Background
Document for solvents to support this
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1720
Vol. Si, Hov 9 / Taeaday. Jantrary
1986 / Proposed Rules
wastewatera, A considerable body of
literature exists documenting the
bJodegradation of soluble organic
compounds via biological treatment. The
range of concentrations of individual
solvents in wastewaters that are
amendable to biological treatment
depends on-the toxicity of the compound
to microbes. The degree of toxicity
depends, in part, on the acclimation
achieved by the microorganisms. The
levels of highly toxic solvents may not
be able to exceed 10 mg/1, whereas
other solvents can be present at over 100
mg/1.
Plants sampled to develop the effluent
guidelines for the organic chemicals and
plastics and synthetic fibers industries
demonstrate the use of biological
treatment, most often activated sludge,
to treat carbon tetrachloride.
chlorobenzene, 1,2-dichlorobenzene,
ethylbenzene, methylene chloride,
nitrobenzene, tetrachloroethylene,
toluene, and trichloroethylene. EPA has
determined that biological treatment is
also demonstrated on the following
constituents based on solubility:
acetone, n-butyl alcohol, carbon
disulfide, cresols, cyclohexanone, ethyl
acetate, ethyl ether, isobutanol.
methanol, methyl ethyl ketone, and
methyl isobutyl ketone, and pyridine.
e. Incineration. The Agency estimates
that there are currently at least 330
individual incineration units (both
commercial and private) burning a
minimum of 317 million gallons of
materials containing solvents per year.
The wastes burned include wastewaters
containing as little as 0.01 percent (100
mg/1) solvents, liquids, and sludges
containing 60 percent (600,000 mg/1) or
more solvents, and primarily inorganic
sludges and solids, such as soils
contaminated with low levels of
solvents. Almost any waste containing
solvents can be incinerated, even those
with low heat value, by blending with
waste of higher heat value or by co-
injecting the waste with fuels.
The majority of the incinerated
hazardous waste is listed as ignitable
waste containing primarily the solvents
listed for FOOS or FOOS wastes. The data
indicate that one or more incinerators -
burned all solvent constituents listed
under F001 through FOOS. EPA data
show thaHgnitable solvent constituents
appear frequently in fuel for
incinerators. Based on this information,
EPA believes that the incineration of all
solvent constituents is demonstrated.*
f. Fuel substitution. According to an
EPA survey of wastes burned as fuel in
1983,1,400 industrial boilers burned
hazardous wastes (Ref. 124). In.addition.
a large volume of the hazardous wastes
burned in these devices contained
chlorinated and ironchkninared solvent
constituents. Data indicate that all of the
solventconstituents listed in'FOOl and
' F005 wastes have been present in
hazardous wastes burned as fuel
substitutes. However, because of their
high chlorine content, and resulting
corrosivity, most F001 and F002 waste
must be blended with other solvents or
fuel prior to burning.
The Agency conducted field tests on
11 full-scale industrial boilers and 9
industrial furnaces (Ref. 105). The test
facilities represented a wide variety of
boiler and furnace types and sizes
burning a variety of hazardous wastes
with a variety of auxiliary fuels. The
hazardous wastes burned ranged from
methanol and toluene wastes with a
heating value similar t« No. 8 fuel oil
(and which was spiked with chlorinated
organics for test purposes} to methyl
acetate waste with a heating value of
less than half that of No. 8 fuel oil (and
which was also spiked with chlorinated
organics for test purposes). The results
of the tests showed that industrial
boilers and furnaces can destory to 99.99
percent destruction and removal
efficiency organic compounds
considered difficult to bum, including
1,1,1-trichloroethane, carbon
tetrachloride, chlorobenzene,
trichloroethylene, and
tetrachloroethylene. Also destroyed
were organic compounds that burn more
easily, such as benzene, toluene, xylene.
and nitrobenzene. In additional EPA
tests of boilers, fuel oil was spiked with
selected organic compounds, including
chloroform, 1,1,1-trichloroethane,
trichloroethylene, and trichlorobenzene
(Ref. 108). Accordingly, EPA believes
that data demonstrate the use as fuel of
the solvent wastes of sufficient heat
varae and aU solvent constituents
addressed ra this proposed rule.
The Agency is currently developing
regulations that will govern the use of
hazardous waste as fuel. These
standards are likely to control hydrogen
chloride emissions. (The Agency already
controls these emissions for •
incinerators.) To meet the emission
standard, owner/operators could limit
the chlorine levels in the waste or rely
on emission control equipment, such as
scrubbers. EPA believes that most
industrial furnaces, and some boilers,
will be able to meet these standards
when burning hazardous solvent wastes
as fuel.
3. Available Treatment Technologies
a.' Proprietary processes. The Agency
has determined mat none of the
demonstrated treatment technologies for
the separation/removal or destruction of
Appendix VD solvent constituents in
F001 through FOOS wastes are
considered proprietary processes.
Therefore, no technologies need to be
excluded from consideration hi
establishing treatment standards based
on their proprietary nature.
The Agency recognizes that
proprietary treatment processes may
also exist for which it has no data. The
Agency solicits comments on specific
proprietary treatment processes for
solvent-bearing wastes, their
performance for each solvent
constituent, and their specific
applicability to F001 through FOOS
solvent wastes and constituents.
b. Analysis of relative risks. The
Agency evaluated 20 representative
solvent waste streams and 10 treatment
and recycling unit processes to
determine if alternative treatment and
recycling methods pose greater risks
than land disposal methods. The results
of this evaluation are summarized here.
More detailed information on this
analysis is given in the Background
Document to the Comparative Risk
Assessment (Ref. 1). Although final
evaluations have not yet been
completed, preliminary results indicate
that the best demonstrated treatment
technologies for solvents do not pose
total risks to human health and the
environment greater than those posed in
the direct land disposal of most
categories of the solvent wastes subject
to today's proposed rulejnaking.
Detailed analyses are underway,
however, to evaluate risks posed by the
treatment of certain categories of
solvent waste streams in steam strippers
and incinerators. Since greater risks
may be posed by these technologies
only for a small subset of the solvent
wastes subject to today's proposed
rulemaking, EPA is continuing to
classify both of these technologies as
available treatment technologies for '
purposes of establishing the section
3004(m) treatment standards until the
results of the detailed analyses are
available. If this analysis indicates that
these technologies are riskier than land
disposal and this determination would
change the treatment standard for these
wastes, a supplemental proposal to this
rulemaking will be issued. The waste
streams and technologies chosen for this
analysis are summarized below and are
described in more detail In the
Background Document to the
Comparative RisJc Assessment (Ref. 1).
The methodology used to perform the
comparative risk assessment is
explained in Unit III.C.
The waste streams chosen for the
analysis are derived from waste streams
already characterized in the RCRA Risk-
-------
Federal Register / Vol. 51, No. 9 / Tuesday, January 14. 1986 / Proposed Rules
distillation); and (2) liquids, sludges, and
solids containing solvents that are not
amenable to these methods. Solvent
wastes from which the solvent
constituents cannot be separated or
removed usually require complete
destruction, using technologies such as
Incineration and fuel substitution.
Often, EPA was not able to determine
if the available data pertaining to the
treatment of solvents referred to the
treatment of RCRA hazardous wastes,
or waste streams that merely contained
the constituents of concern. Therefore,
EPA also studied data documenting
treatment of any waste containing the
solvent constituents addressed by this
proposal (i.e., Appendix Vn constituents
of concern for FOOl through F005
wastes). Where data were lacking for
certain constituents, EPA evaluated
treatment data for similar compounds.
EPA believes that the solvent waste
for which it has treatment data is similar
to solvent waste which is currently land
disposed. Therefore, available treatment
data should apply to most, if not all,
wastes subject to this proposed rule.
EPA recognizes that there may be land
disposed wastes whose treatment is not
represented by available treatment data.
The Agency requests data describing
any such wastes, including the waste
characteristics that would affect their
treatability. These data also should
include data documenting the actual
treatability of the wastes.
EPA studies available data from full-
scale, pilot-scale, and sometimes bench-
scale treatment facilities to determine if
the data demonstrated the treatment of
wastes that adequately represent the
treatability waste groups given above.
EPA has identified the existence of full-
scale, pilot-scale, and bench-scale
facilities that demonstrate the general
applicability of the following
technologies for the treatment of solvent
wastes: biological degradation, steam
stripping, air stripping, carbon
adsorption, distillation, incineration,
and use as a fuel substitute (i.e., in
industrial boilers andffurnaces). The
data, which are summarized below, .
show that all of the solvent wastes and
constituents subject to this rule can be
treated by one or more of these
technologies. Accordingly, EPA
determines that such technologies meet
the "demonstrated" component of the
BOAT standard.
The Agency has determined that the
following potentially applicable
technologies have not yet been
sufficiently demonstrated on the solvent
wastes and constituents of concern:
resin adsorption, chemical oxidation,
wet air oxidation, chemical reduction,
encapsulation, and chemical fixation/
solidification. While the Agency
believes these technologies are
theoretically applicable to many of the
solvents constituents, the lack of
adequate full-scale, pilot-scale, or
bench-scale data for the treatment of the
solvents of concern precludes these
technologies from consideration in
EPA's evaluation of BDAT. The Agency
recognizes that the data on the use of
technologies to treat solvent wastes are
in a constant state of flux as these and
other technologies are being developed
and tested, and as facilities are being
built. EPA believes, however, that the
data available on the use of the
technologies listed above to treat a
representative sample of solvent wastes
is insufficient to show that these
technologies are demonstrated. The
Agency solicits comments and data on
the use of these technologies for treating
solvent wastes, including paired influent
and effluent values and air emissions '
data. This information will assist EPA in
determining whether such technologies
could form the basis of BDAT standards
in the final rule.
a. Steam and air stripping. The use of
steam stripping to remove solvents is a
widely recognized manufacturing
process and waste treatment technology
for separation of dilute solvents from
water. Steam stripping is demonstrated
on wastes containing concentrations of
solvents as high as several thousand
milligrams per liter. The organic
chemicals industry and the pesticides
industry use full-scale steam stripping
facilities to remove-solvents from
wastewaters. Steam stripping is also
used full-scale and pilot-scale to remove
solvents from contaminated ground
water. Recent data indicate that there
are* at least 27 industrial steam stripping
units, both commercial and private. Air
stripping is commonly used full-scale
and pilot-scale to remove solvent
contaminants from ground water, as
well as a pretreatment to biological
degradation. Waste concentrations
amenable to air stripping are typically
less than 100 mg/1.
Based on available treatment data,
EPA believes that steam and air
stripping are especially applicable to the
following solvents addressed in this
rulemaking: chlorobenzene,
ethylbenzene, methylene chloride,
toluene, 1,1,1-trichloroethane, and
trichloroethylene. Steam and air
stripping have also been applied less
successfully to other solvent
constituents, such as acetone, methyl
ethyl ketone, methyl isobutyl ketone,
and nitrobenzene, which are moderately
or slightly volatile. Furthermore, based
on their volatility, EPA believes that
steam stripping is potentially applicable
to eight more solvents; carbon disulfide.l
carbon tetrachloride, chlorobenzene, 1, •
2-dichlorobenzene, tetrachloroethylene, •
l,l,l-trichloro-l,2,2-trifluoroethane, I
trichlorofluoromethane, and xylene. I
b. Carbon adsorption. Activated I
carbon adsorption also is a widely • I
recognized technology for the removal ol
organic compounds from wastewaters. I
Carbon adsorption is normally used to •
treat wastewaters containing less than si
few hundred milligrams per liter of total!
organic constituents, although it has I
been used to treat up to 6,500 mg/1 of I
cresols. EPA has identified I
approximately SO commercial facilities I
with full-scale carbon adsorption units. I
Carbon adsorption has been I
demonstrated to various degrees of I
effectiveness for most of the solvent I
constituents that are the subject of this I
rule. Data from full-scale facilities have I
shown that carbon adsorption is I
particularly effective for removing I
cresols, nitrobenzene, and toluene from I
wastewaters. EPA concludes that I
carbon adsorption is a demonstrated I
technology for the treatment of solvent I
wastes and constituents. I
c. Distillation. EPA estimates that I
there are at least 43 full-scale I
commercial solvent recyclers using I
some form of distillation for at least 149 I
million gallons per year of solvents I
listed as FOOl through F005. In addition, I
data indicate that there are over 4,000 I
on-site solvent recyclers. Data are I
somewhat limited on these facilities I
because of their partial and previous • I
exclusion from regulation under RCRA I
(see Unit in.B). Also, approximately 18 I
million gallons of solvents produced by I
small quantity generators are recycled, I
principally by distillation. Data show I
that.the following solvent constituents I
have been reclaimed by distillation: I
acetone, n-butyl alcohol, carbon I
disulfide, carbon tetrachloride, I
chlorobenzene, cyclohexanone, 1,2- I
dichlorobenzene, ethyl acetate, I
ethylbenzene, isobutanol, methyl I
isobutyl ketone, methanol, methylene I
chloride, tetrachloroethylene, I
trichloroethylene, 1,1,1-trichloroethane, I
and trichlorofluoromethane. Based on I
this information, EPA finds that I
distillation is a demonstrated technology I
for the. treatment of certain solvent I
wastes (i.e., those with high enough I
organic and low enough solids content). I
As explained earlier, in most cases, I
further treatment of the distillation still I
bottoms is required. I
d. Biological degradation. Biological I
degradation is practiced extensively in I
the organic chemicals, Pharmaceuticals,
and related industries for the removal of
soluble organic compounds from
-------
1722
Federal Register / VoL 51. No. 9 / Tuesday. January 14, 1986 / Proposed Rules
TABLE 11--PEREOHMANCE ACHIEVED BY BOAT (MG/L)
Constituent
Acetone
n-Butyl alcohol
Carbon disulfide
Carbon tetrachloride
Chlorcbenzene
Cresols
Cyclone xanone
1 , 2-Di Chlorcbenzene
Ethyl acetate
Ethylbenzene
Ethyl ether
Isobutanol
Methanol
Methylene chloride
.Methyl ethyl ketcne
Methyl iscbutyl ketcne
Nitrobenzene
Pyridine
Tetrach loroethy lene
Toluene
lii/JL-Trichloroethaner.
1 / 1 > 2— Trichloro-1 ,2/2—
trif luoroethane •
Trichloroethylene
Trichlorof luoromethane
1
Xylene
Screenin
Level
2.0
2.0
2.0
0.1
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
1.2
2.0
2.0
0.09
0.7
0.015
2.0
2.0
2.0
0.1
2.0
2.0
g Steam
Stripping^
0.200
0.109
0.036
0.457
0.4572/
0.019
0.4572/
Carbon
Adsorption
0.62
0.027
- 0.016
Biological
<0.050l/
<0.10Q2/
<0.010
0.292
<0.10Q2/
<0.10Q2/ .
0.302
<0.10Q2/
<0.010
<0.05Q2/
<0. 1002./
0.011
<0.05Q2/
<0.01Q2/
<0.010'
<0.50Q2/
<0.010
0.066
0.011
/Combination
0.0623/
0. 053l/
0.0261/
0.23Q3/
<0.005V
Fuel
Substitution/
<0.0502/
<0 1002/
<0 0102/
<0.010
<0.020
<0.100
<0.1002/
<0.0102/
<0 0102/
<0.1002/
<0.1002/
<0.050
<0.0102/
<0.0102/
<0. 5002/
<0.010
<0.010
<0.010
<0.0102/
<0.010
<0.0102/
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Fadtetrf Ktgtrter / Vol. 51. No. 9- / Tuesday, January M, 19B6 / Proposed Rules
Coat Analysis (WET) Model database
(Ref. 118). In general, the wastes
represent wastewatere, concentrated
organic liquids, and organic sludges
containing various concentrations of
hazardous constituents. Wastes that
contain only solvents, as well as those
that contain both solvent and metal
constituents, are represented.
The waste streams containing only
solvent constituents range in
concentration from 0.5 percent (5,000
mg/1) to 80 percent (800,000 mg/1), a
range EPA judges to be representative of
the solvent concentration in listed
hazardous wastes. Because not all
solvent constituents of concern could be
modeled, EPA chose the constituents
based on the frequenty of their
occurrence hi F001, F002, F003, F004, and
F005 wastes codes. Also, the quality of
toxicity data available for each
constituent influenced the choice of
constituents. In order to simplify the
analysis, the waste streams contain
either halogenated solvent constituents
(e.g., 1,1,1-trichloroethane, carbon
tetrachloride, methyl chloride,
chloroform) or nonhalogenated
compounds (e.g., benzene, toluene, m-
xylene).
The waste streams containing both
solvent and metal constituents are either
wastewaters containing as little as .012
percent (120 mg/1) solvents and 0.1
percent (1,000 mg/1) metals or
concentrated streams containing as
much as 60 percent (600,000 mg/1)
solvents and 6 percent (60.000 mg/1)
metala. EPA believes that this range
represents the range of concentrations
present in RCRA-listed hazardous
wastes that also contain solvent
constituents. The metals chosen for the
analysis are the following: lead.
mercury, thallium, choromium (VI),
cadmium, and arsenic. These metals
correspond to those in the California
List.
For the purposes of this evaluation,
numerous treatment and recycling unit
processes were combined to form
treatment trains. These sequences
represent treatment trains that EPA
judges will meet the treatment
standards ultimately established. All
•demonstrated technologies are
represented, as well as those that do not
meet EPA's criteria for demonstrated,
but may be able to meet the treatment
standards for some, wastes. The unit
processes evaluated for the solvent
constituents include steam stripping,
distillation, carbon adsorption, and
incineration. EPA has not yet completed
the evaluation of biological degradation
and air stripping. To the extent that the
results of the comparative risk
assessment for these technologies would
affect the treatment standards proposed
today, a supplemental proposal to this
rulemaking will be issued.
Treatment systems for treating solvent
wastes that also contain metals often
incorporate unit processes to remove the.
metal constituents. In order to assess
the total risk associated with the
treatment of solvent wastes containing
metals, the treatment trains modeled
and evaluated for these waste streams!
include the following: chromium
reduction, chemical precipitation, sludj
drying beds, vacuum filtration,
centrifugation, and lime fixation.
Both surface impoundments and
landfills were used to simulate the lanj
disposal. Liquid waste streams were
presumed to be land disposed in surfal
impoundments and sludges and solids |
were presumed to be landfilled.
4. Determination of BOAT and
Achievable Concentrations
The Agency evaluated performance |
data for the five processes .that are
demonstrated treatment/recycling
technologies for the treatment of
hazardous wastes containing solvents:]
Steam stripping, carbon adsorption,
biological degradation, distillation.
incineration, and fuel substitution. EP/
found that BDAT for solvent wastes an
constituents amenable to separation/
removal techniques is either steam
stripping, carbon adsorption, biologic
treatment; or some combination of thesj
processes. BDAT for solvent wastes nc
amenable to separation/removal
methods is either incineration or fuel
substitution.
The best performance achieved by
BDAT for each solvent constituent
addressed today is given in the
following Table 11:
BILLING CODE 6560-50-M
-------
Based cm available data and chemical
properties (i.e., vapor pressure and
water solubility) the Agency believes
that steam stripping is potentially
applicable to wastewaters contaminated
with any of the F001 through F005
solvent constituents for which steam
stripping is indicated in Table 11. The
low levels (i.e., levels approaching
detection limits) for these solvents
achieved by steam stripping indicates
that steam stripping is BDAT for these
solvents. EPA recognizes that there may
be other constituents present which may
preclude application of this technology
and solicits comments on such
constituents, as well as paired influent
and effluent data for steam stripping of
solvents. The Agency requests comment
on the design characteristics necessary
to achieve these concentrations for
wastes listed under F001 through F005
waste codes.
c. Carbon adsorption. Data on carbon
adsorption indicate that all solvent
constituents for F001 through F005
wastes are adsorbed to some extent.
Carbon adsorption produces
exceptionally low concentration
(approaching detection limits) for only
three solvent constituents: cresols,
nitrobenzene, and toluene. These
concentrations for these, which were
achieved in full-scale carbon adsorption
units, are given in Table 11.
As with steam strippers, carbon
adsorption units need to be specifically
designed and operated to achieve
adequate removal of solvents based on
the influent concentration and other
constituents present in the waste
treated. The Agency recognizes that
carbon adsorption is particularly
sensitive these variables, and that even
with pretreatment, this technology may
not be applicable or the specified levels
achieved on specific waste matrices that
would demand an excessively large
amount of carbon. EPA solicits
comments on such variables and solicits
paired influent and effluent data for the
removal of solvents by activated carbon.
d. Biological treatment. As discussed
earlier, data on biological treatment
demonstrated that it can be applied to
all solvent constituents when they are
present at levels in wastewater that are
nontoxic to acclimated microorganisms.
Table 11 indicates the solvents for
which performance data are available
from well-operated biological treatment
systems. These constituents are the
following: carbon tetrachloride, -
chlorobenzene, 1,2-dichlorobenzene,
ethylbenzene, methylene chloride,
nitrobenzene, tetrachloroethylene,
toluene, and trichloroethylene. The
biological treatment methods used
include activated sludge, trickling filters,
and aerated lagoons. Because the levels
achieved shown in Table 11 are very
low (approaching detection), biological
treatment is BDAT for these solvents.
EPA also believes that very soluble
compounds can be removed to their
detection limits, even though
performance data are not available for
these compounds. These constituents
are the following: acetone, n-butyl
alcohol, cresols, cyclohexanone, ethyl
acetate, ethyl ether, isobutanol,
methanol, methyl ethyl ketone, methyl
isobutyl ketone, and pyridine. As noted
earlier, a great deal of literature exists
to support EPA's contention that the
compounds listed above are highly
biodegradable, include bench- and pilot-
scale data for some constituents. EPA
believes that biological treatment is
BDAT for these solvents. However,
because data, particularly, from full-
scale systems, have not been identified,.
EPA encourages comment that provides
paired data showing influent and
effluent data for biological treatment of
these constituents, as well as resulting.
concentrations of constituents in the
sludge. EPA also invites comment on the
loading rates and detention times
necessary to remove these and other
constituents to their detection levels in
properly operated biological treatment
units, and the rate at which air or
oxygen are added during treatment.
e. Combinations of wastewater
treatment technologies. There are at
least three general combinations of
demonstrated technologies that also are
used to treat solvent wastes. Steam
stripping can be used prior to biological
treatment to reduce relatively high
solvent concentrations that would
inhibit biological activity. Activated
carbon can also be used following
biological treatment for solvents to
reduce the carbon capacity req'uired to
achieve the'desired performance. Lastly,
all three technologies can be used in the
same treatment system.
As shown in Table 11, available data
indicate that activated sludge followed
by granular activated carbon is BDAT
because of the low levels achieved for
four solvent constituents:
chlorobenzene, 1,2-dichlorobenzene,
nitrobenzene, and toluene. Granular
activated carbon followed by steam
stripping is BDAT for xylene. The
Agency solicits additional data
pertaining to the performance of these or
other technology combinations. EPA
solicits paired data on the performance
achieved by these systems and.the
design characteristics appropriate for
the combined system.
f. Distillation. Distillation is a method
to separate a solvent or solvents from
•: other organic constituent of a waste,
including other solvents. It is also used
to purify a solvent by separating the
solvent from containments (e.g., water).
Distillation is normally used to reclaim
solvents from wastes containing high '
concentrations of solvents and low
levels of solids, usually leaving behind a
sludge (still bottom). Data indicate that
the residual ranges from 9 to 44 percent
of the volume of the waste prior to
distillation, with an average residual
volume of approximately 15 percent.
This residual sometimes contains even
higher concentrations of solvents than
the original waste.
EPA believes that distillation can be
considered a waste concentration and/
or volume reduction step in a treatment
train which includes destruction of the
still bottoms. However, based on
available information, distillation alone
does not appear to achieve low levels of
solvents in the waste residual, and
therefore is not considered BDAT for
any solvent waste. EPA requests data -
on the performance of distillation,
including the concentration of solvents
(and metals) in the influent, still
bottoms, and reclaimed solvent.
Information on the percent solids
present in the still bottoms is also
requested.
g. Incineration. Incineration is
demonstrated on all solvent constituents
listed in F001 through F005 waste.
Incineration has been performed on
liquids, sludges, and solids, most of
which are not amenable to wastewater
treatment. Incineration has achieved
99.99 percent destruction and removal
efficiencies in the air emissions for all
solvents! However, in this rulemaking,
EPA is concerned with the wastes and
residuals going to land disposal, such as
the incinerator ash and the scrubber
water. Data are available characterizing
scrubber water from four full-scale
incinerators, and ash from three of these
incinerators, operating at 99.99 percent
ORE for air emissions during test burns
(Ref. 77). The feed for these incinerators
contained nine of the solvent
constituents subject.to this proposed
rule, including difficult to incinerate
chlorinated solvents. In most cases, the
solvent constituents were not detected
in the scrubber water or the ash. Based
on this information, the Agency believes
that the scrubber water and ash from an
incinerator achieving the 99.99 percent
DRE for air emissions will not contain
detectable levels of any of the solvent
constituents addressed in this proposal.
Incineration is therefore DBAT for
incinerable solvent wastes Performance
-------
Federal RagWar / VoE SI, No. 9 / Toeaday, January 14. 1986 / Proposed Rules
Footnotes
1 Includes activated sludge, trickling filters.
and aerated lagoons.
1 Estimated value.
3 Activated sludge followed by granular
activated carbon.
* Granular activated carbon followed by
steam stripping.
The screening concentration levels or
liner protection thresholds discussed in
Unit VJ2. are also listed. As explained in
Unit IILB. whenever BOAT achieves the
screening or liner protection
concentrations, treatment is substantial.
Because BDAT for solvent wastes
achieves these concentrations for each
solvent constituent. BDAT for solvents
is substantial treatment in all cases. The
basis'for determining BDAT
concentrations is discussed in this unit.
In Unit V.G the Agency discusses the
comparison of the performance of BDAT
to the screening concentration levels
established in Unit V.E.
It is important to note that, although
destruction techniques such as
incineration and fuel substitution are
capable of completely destroying
solvent wastes and constituents, many
solvent constituents present in
wastewaters cannot be completely
removed by separation/removal
processes. Therefore, BDAT levels
achievable for these constituents in
wastewater are higher than those
achieved by incineration or fuel
substitution. The Agency believes that
the more concentrated solvent wastes
will be destroyed by incineration or fuel
substitution because wastewater
treatment of these wastes is impractical.
Thus, it is unnecessary for the Agency to
establish different performance
categories for wastes amenable to
incineration versus wastewater
treatment to assure that BDAT is used.
(n the case of solvents, both
technologies meet the screening or liner
protection levels described hi Unit V.E,
as discussed below.
a. Analysis of performance data. EPA
is aware of numerous reports in the .
technical literature as-to-the solvent
concentrations achieved by the
demonstrated technologies identified
previously. These concentrations show a
wide variation in performance. EPA
believes that this is explained by the
fact that solvent separation technologies
are designed to achieve specific
efficiencies for the projected influent
loading. Therefore, the performance of
solvents treatment is controlled by the
design and operation of the treatment
system, i.e., rate of heat transfer for
steam stripping, amount of activated
carbon per volume of wastewater, and
detention time and aeration rate for
biological treatment.
As a result, EPA does not intend to
pool all available performance data,
regardless of design, in developing
treatment standards. Instead, EPA
intends to review the available
performance data and determine the
concentration achievable by a
"reasonable" design and operation for
such equipment. EPA'a test for
reasonable will be whether a given
constituent concentration is achievable
by systems the Agency judges to be
comparable to the "best" systems now
in use. even if no data currently exist to
document the treatment of a solvent
constituent to this concentration using
the "best" system. EPA will not consider
as reasonable unusually repetitious
treatment systems or the use of other
designs or operation that are
inconsistent with standard engineering
practice. EPA solicits comment -on the
actual designs of demonstrated
technologies necessary to achieve the
BDAT levels identified in Table 11 and
the reasonableness of providing
treatment systems that meet these
design specifications.
Furthermore, EPA did not include
effluent data for the treatment of wastes
that contains solvent concentrations less
than the health-based or liner effects
thresholds. EPA believes that the
inclusion of such data would skew the
results towards an unreasonably low
performance number.
Performance data for those
technologies determined to be
demonstrated are summarized in this
unit. All specific technical data are
available in the Background Document
for solvents to support this proposed
rule (Ref. 4).
b. Steam (and air} stripping.
According to available data, steam
stripping achieves lower effluent
concentrations for solvent wastes
containing higher concentrations of
solvent constituents than does air
stripping. EPA concludes that steam
stripping, and not air stripping, is BDAT
for certain wastewaters containing
solvents. As stated previously, steam
stripping has been applied in
wastewaters containing up to several
thousand milligrams per liter of solvent
constituents.
Data on steam stripping of solvent
constituents is available for many of the
solvent constituents addressed in this
proposal. Because EPA believes that the
performance of steam stripping is
design- and operation-limited, it chose
to evaluate data for the performance of
only optimally designed and operated
steam stripping devices. Based on data
from these types of units, steam
stripping is BDAT for five solvent
constituents of concern: ethylbenzene,
methytene chloride, toluene, 1,1.1-
trichloroethane, and trichloroethylene.
Henry's Law Constants, which take
into account vapor pressure and water
solubility, are an excellent theoretical
indicator of the ease with which
chemical compounds can be stripped.
Compounds with Henry's Law
Constants greater then 10~»are generallj
considered highly volatile. Based on
their Henry's Law Constants, eight
additional solvents are highly volatile.
(Henry's Law Constants can be found i
Refs, 4, 78, and 117.) These constituents |
are the following: carbon disulfide,
carbon tetrachloride, chlorobenzene, 1,2|
dichlorobenzene, tetrachloroethylene,
l,l,2-trichloro-l,2,2-trifluoroethane,
trichlorofluoromethanet and xylene.
Their high volatility indicates that stear
stripping is potentially BDAT for these
solvents.
Because no other treatment data are
available for the two most volatile
splvents, l,l,2-trichloro-l,2,2,-.
trifluoroethane and
trichlorofraoromethane, EPA is
estimating that these solvents can be
steam stripped to at least the level that
can be achieved for 1,1,1-
trichloroethane, or 0.457 mg/1. The
Henry's Law Constant for 1,1,2-trichloro
1.2,2,-trifluoroethane is two orders of
magnitude larger than that of 1.1,1-
trichloroethane: the Henry's'Law
Constant for trichlorofluoromethane is
one order of magnitude larger. Because
these solvents are far more volatile than)
1,1,1-trichloroethane, EPA believes that
at the very least the performance given
above can be- achieved, hi the final rule. |
EPA also may decide to extrapolate
steam stripping performance for the
other volatile solvents. EPA requests
influent and effluent stripping data on
these solvents, as well as design and
operational information on the steam
stripping units used to treat them.
Several other constituents with
Henry's Law Constants ranging from 8.7.|
x 10~4 to 1 x 10~s are reported to be
moderately volatile: ethyl ether, ethyl
acetate, methyl ethyl ketone, methyl
isobutyl ketone, cyclohexanone.
nitrobenzene, and isobutanol. Solvent
constituents that are slightly volative
(Henry's Law Constant between 7.0 x
l(r« and 9.5 x 1(T 'J include n-buryl
alcohol, acetone, cresols, and methancl. |
Pyridine is reported to be nonvolatile.
Conceivably, given high temperatures
and long retention times, the moderately |
and sligfitly volatile constituents can be
• steam stripped to low levels. However,
EPA has little or no data showing that
steam stripping alone achieves the
lowest levels possible for these
constituents.
-------
Federal geglgter / VoL 51, No. 9 / Tuesday. Januaiy 14, 1988 / Proposed
1. Summary of Volume* of Wastes Land
Disposed Annually
EPA estimated the quantity ot
hazardous waste listed under F001
through F005 waste codes and the
corresponding P and U waste codes that
is currently land disposed annually. The
estimates are based primarily on the
data provided by the OSW RIA Mail
Survey of hazardous waste management
activities in 1981 (Ref. 116). The analysis
of the Survey data is summarized in this
unit. A more detailed assessment is
given in the Background Document for
solvents to support this proposed rule
(Ref. 4).
Because concentration data are not
provided by the Survey, EPA is
assuming that all hazardous waste
identified as F001, F002, F003, F004, or
F005 or the corresponding P and U
waste codes in the Survey exceeds the
treatment standards proposed today and
that this waste will be banned from land
disposal.
EPA estimates that approximately 214
million gallons of the total quantity of
solvent waste per year that is land
disposed will require alternative
treatment or recycling capacity. Of this
total, the Agency estimates that 185
million gallons (86.4 percent) are
solvent-water mixtures (i.e., aqueous
wastes), 14.7 million gallons (6.9
percent) are organic liquids, 7.3 million
gallons (3.5 percent) are organic sludges
or solids, and 6.7 million gallons (3.2
percent) are inorganic sludges or solids.
EPA does not know which surface
impoundments will meet the
requirements of RCRA section
3005(j)(ll)(A) and (B), thus allowing
their continued use for treatment. (See
Unit EC for a discussion of the
exemption for treatment in surface
impoundments.) In the calculations to
determine the total quantity of waste
requiring alternative capacity, EPA has
assumed that surface impoundments
accounting for 80 percent of the volume
of solvent-water mixtures treated in
surface impoundments will continue to
operate under this exemption. This
assumption is consistent with the
economic impact assessment prepared
in support of this rule and is based
primarily on the economic feasibility of
meeting the section 3005{j)(ll)(A) and
(B) requirements (Ref. 9).
For the purposes of this proposed
rulemaking, the Agency is also assuming
that solvent wastes described as organic
liquids contain greater than 1 percent
total organic content by weight, and
those described as solvent-water
mixtures contain less than 1 percent.
The basis for this assumption are data
for three facilities with large-volume
aqueous waste streams which account
for 94 percent of the total volume of
solvent-water mixtures treated or
disposed of in surface impoundments
annually. These waste streams are
characterized as greater than 99 percent
water and less than 1 percent total
solvents. Because there is no standard
method for the determination of total
solvent content, EPA is assuming that
these waste streams contain few
additional organic constituents, and that
their total organic content is also less
than 1 percent. Total organic content
can be measured by the test for total
organic carbon (TOG) (see 40 CFR
136.3).
EPA is also assuming in this rule that
wastes characterized as solvent-water
mixtures contain less thanl percent
total solids and those described as
sludges contain greater than 1 percent
total solids.
2. Required Treatment and Recycling
Capacity
In order to determine the treatment
and recycling capacity required to
address the volumes of wastes given
above, these wastes must be assigned to
treatment and recycling methods. EPA
can then compare this demand for
treatment and recycling capacity to the
available unused capacity of these
alternative methods to land disposal.
The Agency recognizes that the actual
application of a technology to a specific
solvent waste is highly dependent upon
waste characteristics such as the
content of solvents, halogens, metals,
water, and the heat value as fuel. As
noted above, the concentration data for
solvent wastes currently land disposed
are limited. However, EPA can use the
available data describing land disposed
waste, to approximate the most likely
alternative treatment and recycling
technologies for all wastes in a waste
group. The rationale for assigning
specific types of solvent wastes to one
of these alternative technologies is
summarized below. For more
information, see the Background
Document for solvents to support this
proposed rule (Ref. 4).
a. Solvent-water mixtures. As given in
Unit V.H.1, liquids containing solvents
and water comprise 185 million gallons
(86.4 percent) of all solvent wastes
currently land disposed each year.
Almost all of these wastes (99.9 percent)
are handled.in surface impoundments.
As stated earlier, EPA estimates that
aqueous mixtures contain-less than 1
percent total organics and less than 1
percent total-solids.
The low organic content and high
water content of these wastes result in a
waste with little or no heat value. EPA
has evaluated data which indicate that
some solvent-water mixtures with as
low as 0.01 percent total solvent content
have been incinerated, but incineration
of these wastes requires a great deal of
blending with wastes of higher heat
content. The Agency believes it is
unlikely that relatively dilute solvent-
water mixtures will require incineration
capacity. For the same reasons, this
waste is not amenable to use as a fuel
substitute. Also, distillation, the most
common means of reclaiming solvents,
generally requires concentrations of at
least 10 percent solvents. Based on this
information, EPA is estimating that none
of the 185 million gallons of solvent-
water mixtures that are currently land
disposed and that require alternative
capacity will be used as a fuel
substitute, incinerated, or sent to solvent
reclamation.
Accordingly, the Agency is assuming
that the entire 185 million gallons of
solvent-water mixtures land disposed
annually require some form of
wastewater treatment technologies
applicable to dilute waste. Wastewater
treatment technologies identified in Unit
V.F include biological degradation,
chemical oxidation, steam stripping, and
carbon/resin adsorption. As discussed
in Unit V.F, biological degradation,
steam stripping, and carbon adsorption
are demonstrated on many solvent
wastes, and the treatment standards
given in Unit V.G are based on these
methods. In addition, chemical
oxidation and resin adsorption, although
not demonstrated for a wide variety of
solvents, are capable of achieving the
treatment standards for some solvent
wastes.
Solvent-water mixtures may be
treated by many different combinations
' of wastewater treatment technologies
sequenced in various process trains
taking place in tanks. The choice of
treatments will depend on specific
waste characteristics and economic
factors, and EPA data are currently
insufficient to determine precisely the
volumes of wastes that would require
any specific wastewater treatment.
Because EPA currently lacks these data,
it is unable to determine the future
capacity needs for specific wastewater
treatment methods. For the purpose of
determining capacity needs in tnis
proposal, it is necessary for EPA to
group solvent-water mixtures of less
than 1 percent total organics into one
treatability group of wastes, all of which
require some form of wastewater
treatment. So that EPA may better ,
define capacity needs by technology, it
requests information on the treatment
technologies that generators will choose
-------
Federal Register / Vok Sl\ Ng;9-'/ Tuesday, January 14. 1986 / Proposed"Rules-
based on both actual data and EPA
estimates is given in Table 11.
EPA is currently gathering more data
on the presence of hazardous
constituents in incinerator ash and
scrubber water. EPA solicits additional
paired data on the concentration of
solvent constituents in incinerator feed.
influent and effluent scrubber water,
and fly and bottom ash to compare to
these data.
Solvents containing metals may result
in ash residuals that require additional
treatment to immobilize the metal -
constituents, and in scrubber water that
must be treated to remove metals.
Treatment standards for some metals
will be addressed in a later rulemaking.
h. Fuel substitution. Use of these
solvents as a fuel substitute is
essentially identical to incineration of
these wastes. Industrial boilers and
furnaces, such as cement and lime kilns,
burn solvent wastes directly as fuel or
indirectly by blending it with auxiliary
fuel. As discussed earlier, halogenated
solvent constituents, although the most
difficult to burn, can be destroyed in
industrial boilers and furnaces to
achieve 99.99 percent ORE in the air
emissions from these devices (Ref. 105).
Therefore, EPA believes that, like
incinerators, industrial boilers and
furnaces which are capable of meeting
99.99 percent DRE will not produce-
residuals with detectable levels of the
solvents addressed in this rule. EPA
concludes that use of solvent wastes as
fuel is BOAT for solvent wastes recycled
in this way.
Some existing data indicate that
certain types of industrial furnaces (e.g..
aggregate kilns] do not combust waste
as well as other types of devices that
utilize solvent waste as fuel. It is unclear
if the. residuals from these devices will
achieve the low levels of solvents in
their residuals that are achieved by
incinerators. EPA solicits paired data on
the concentration of solvent constituents
in hazardous wastes used as fuel in
industrial boilers and furnaces, and the
levels of these constituents in residual
scrubber water, fly ash, and bottom ash
from these devices.
i. Request for comment. The Agency
solicits comments and data which
pertain specifically to the performance
of destruction, removal, or
immobilization methods for solvent
constituents listed in F001 through F005
wastes. The Agency solicits this type of
data for any of the demonstrated
technologies, as well as any of the
technologies previously identified as
potentially applicable to solvent wastes.
In order to assess treatment
performance properly, these data should
include waste codes, physical/chemical
form of the waste, initial concentrations,
all residual concentrations (i.e., air,
water discharges) and teachability" of
solid residuals, as well as design and
operating parameters for the technology.
G. Comparison of BOAT and Screening
Levels
The following Table 13 gives the
technology-based levels, the screening
or liner protection thresholds, and the
treatment standards for each solvent
constituent of F001 through F005 wastes:.
TABLE 13.—COMPARISON OF SCREENING AND
LINER PROTECTION THRESHOLDS WITH
TECHNOLOGY-BASED LEVELS AND THE
TREATMENT STANDARDS (MG/L)
Constituent
Acetone
n-8utyl alcohol...
Carbon
disulfide
Carbon
tetrachloride...
Chkxobenzene ..
Cresols.
Cycfohexanone..
1.2-
Dictitofoben-
zene
Ethyl acetate
Ethylbenzene
Ethyl ether.
Isobutanol
Methanol :...
Methylene
chloride.. _..
Methyl ethyl
ketone
Methyl sobutyl
ketone
Nitrobenzene
Pyndine
Tetrachloroeth-
ylene
Toluene
1.1,1-
Trichloroeth-
ane
I.1.2-Trichloro-
1,2.2-
trrfluaroettt-
gne
Tnchloroethy-
lene
Trichkxofluoro-
methane ^
Xylene
Screening/
Liner
protection
threshold
2.0
2.0
2.0
0.1
2.0
2.0
2.0 .
2.0
2.0
2.0
2.0
2.0
2.0
1.2
2,0
2.0
0.09
0.7
0,015
2.0
£0
2.0
0.1
2.0
2.0
Technology-
based level
1 <0.050
' <0.100
1 <0.010
<0.010
<0.062
'<0.100
'<0.100
0.053
' <0.100
' <0.010
'<0.100
1 <0.050
' <0.100
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51, No. 9 / Tneaday, January 14, 1986 / Proposed Rules
cleanups will be similar in type and
quantity to wastes removed in the past
Lastely, EPA must determine the
quantity of CERCLA waste mat
represents an increase in the demand
for capacity over current treatment and
recycling practices for CERCLA waste.
Such an increase may result from the
land disposal restrictions. However, the
Agency's recent policy emphasizing the
use of alternatives to land disposal for
CERCLA wastes may assert a greater
demand on capacity. Capacity demand
also depends heavily on the number of
CERCLA actions and the extent of each
cleanup.
Because of the problems that this
analysis entails, EPA has not yet
completed its estimates of the future
alternative capacity demands presented
by CERCLA waste. The results of this
evaluation wilt be included hi the final
rule. For the purposes of this proposal.
however, EPA is assuming that the
alternative capacity (e.g., incineration)
required by CERCLA wastes will remain
at its current rate of use.
f. Summary of capacity needs. In the
previous units, the Agency estimated
that the quantity of solvent wastes
requiring wastewater treatment is 185
million gallons. Wastewater treatment
will be performed by a variety of
treatment methods (e.g., biological
degradation, steam stripping, or carbon
adsorption) occurring in tanks. The
quantity of solvent wastes requiring
incinerator capacity annually is 22.4
million gallons of organic liquids,'
sludges, and solids and &7 million
gallons of inorganic sludges and solids,
for a total of 29.1 million gallons. The
volume of waste requiring distillation
capacity each year is 8.6 million gallons
of halogenajed and nonhalogenated
organic liquids. The following Table 14
summarizes these quantities:
TABLE 14.—ANNUAL TREATMENT AND RECOV-
ERY CAPACITY DEMAND BY TECHNOLOGY
[Million gallon* par yawl
attoa
DistBa-
tjon
Solvent-Waster
Mixture*
Hatogenated Organic
Liquids
Nonhalogenated
Organic 1
Hategenaled Organic
Sludges and SoMs...
Nonhatagenatad
Organic Stodge*
and Solids
Inorganic Sludges and
Solid*.._
Total
18S
5.5
S.5
7.2
3.2 .
5-4
3.2
28.1
8.8
3. Unused Capacity of Treatment and
Recycling Facilities
' In the previous units, EPA estimated •*
that solvent wastes restricted from land
disposal as a result of these proposed
rules will be directed to incineration and
wastewater treatment methods that can
achieve the treatment standards given in
Unit V.G. Some solvent wastes will also
be directed to recycling methods for
solvent wastes including distillation and
the use of waste as fuel. In this unit EPA
estimates the unused capacity mat is
currently available, or will soon be
available, to treat or recycle solvent
wastes by these methods.
As explained in Unit IILE, private
treatment recycling, and disposal
capacity will be considered in two
circumstances: (1) if a private owner or
operator plans to accept banned waste
commercially when the ban becomes
effective; or (2) when a private owner or
operator has excess capacity to manage
his own banned waste. At this time EPA
does not have information on the extent
to which these circumstances will occur.
The Agency plans to conduct a
treatment storage, and disposal facility
(TSDF) survey in the near future which
it hopes wiil provide data on the
availability of private capacity to
manage hazardous wastes that are
banned from land disposal. However,
for the purposes of this proposed
rulemaking, the determinations of the
capacity to treat and recycle solvent
wastes will be based solely on unused
commercial capacity. EPA requests
comment and information on the
availability of private treatment and
recycling capacity to manage the solvent
wastes addressed today. The Agency
will consider the capacity of private
treatment and recycling facilities if the
required information becomes available
before the final rule is promulgated.
a. Capacity of wastewater treatment
facilities. As discussed in Unit V.F.,
BDAT wastewater treatment methods
for solvent-water mixtures are biological
degradation, steam stripping, and
carbon adsorption. In addition, other
technologies, such as resin adsorption,
although not BDAT, may be capable of
meeting the treatment standards for
some wastes (s«e Unit V.G.). All of the
treatment methods are referred to as
tank treatment under the RCRA TSDF
regulations.
The OSW RIA Mail Survey (Ref. 118)
is currently EPA's only source of
information concerning the unused
capacity at tank treatment facilities. The
Survey provides information on tank
capacity at both commercial and private
facilities treating F001 through F005
solvent wastes, although the data at
wastewater treatment facilities
exempted from RCRA requirements are
•somewhat limited. As discussed above,
EPA will consider only commercial
wastewater treatment capacity hi this
proposed rulemaking.
The Survey data provided little
information on specific treatment
methods. Therefore, EPA estimated the
total unused tank capacity at
commercial facilities that treat solvents.
This unused capacity is approximately -
112 million gallons. This quantity
represents the difference between
planned design capacity (full capacity)
of approximately 170 million gallons per
year and used capacity of
approximately 58 million gallons per
year.
Because treatment faculties seldom
operate at full capacity, the estimate of
112 million gallons improbably high. In
addition, these commercial facilities
treat other hazardous wastes, and EPA
is not able to determine the portion of
the 112 million gallons of unused
capacity that is available to treat
solvent wastes. In conclusion, the tank
capacity dedicated to treat solvent
wastes at commercial facilities is less
than 112 million gallons.
b. Capacity of incinerators and
distillation. EPA estimates that unused
commercial incineration capacity is less
than 25.8 million gallons per year. This
calculation is based on the maximum
design capacity of on-line,commercial
incinerators and a utilization rate of 80
percent (see Ref. 4). The Agency
believes that this capacity is the
maximum capacity available to
incinerate solvent wastes. It requests
comments on the utilization rate of 80
percent reported by several incinerator
owner/operators. As discussed earlier,
EPA has insufficient data to estimate the
additional quantity'of solvent liquid
wastes that will be incinerated privately
hi the future. EPA requests data to help
determine these quantities. In addition,
several companies have proposed to
build new rotary kiln incinerators that
would operate commercially. However,
at this time, construction has not begun
on any of these facilities. Therefore, the
Agency is unable to project when these
incinerators will be completed, and
capacity mat they would provide cannot
be considered for this proposed
rulemaking. The final rule will consider
the capacity of these facilities if such
information becomes available.
As stated earlier, distillation of spent
solvents is widely practiced. EPA
estimates that unused commercial
capacity for distillation totals 225
million gallons per year. EPA believes
that a large number of distillation
-------
Federal Register / Vol 51. No^-9./ Tuesday, January 14. 198fr / Proposed Rules
to replace land disposal of solvent-
water mixtures, and the factors.that will
influence this decision.
b. Organic liquids. As described in
Unit V.H.1. EPA estimates that currently
14.7 million gallons of organic liquids
are land disposed each year, and that
these wastes contain greater than 1
percent total organic constituents. In
addition, 5.9 million gallons of wastes
generated by small quantity generators
(SQGs) are organic liquids and will
compete for alternative capacity with
currently land disposed organic liquids.
EPA believes that the organic liquids
produced by SQGs are similar to the
organic liquids currently land disposed.
Therefore, a total of 20.6 million gallons
of organic liquids require alternative
capacity. EPA estimates that 10.9 million
gallons of organic liquids contain
principally halogenated organic
constituents and 9.7 million gallons
contain nonhalogenated organics.
Because of their higher organic
content (greater than 1 percent), EPA
estimates that all organic liquids are
amenable to incineration, although some
of these wastes may require blending
with wastes of higher heat value. As
discussed in Unit V.F, EPA believes that
incineration can meet the treatment
standards given in Unit V.G for solvent
wastes.
EPA also believes that some of these
organic liquids can be reclaimed by
distillation or used as fuel substitutes.
Distillation is a volume reduction or
concentration step in a treatment
process which also must include
destruction of the distillation still
bottoms, either by incineration or fuel
substitution, in order to meet the
treatment standards. EPA estimates that
currently at least 428 million gallons of
spent solvents are reclaimed by
distillation each year.
As Unit YJF. explains, fuel
substitution is equivalent to incineration
in its ability to destroy solvent was.tes.
Hazardous wastes containing solvents
are often used as fuel substitutes.
Approximately 159 million gallons of
wastes containing sofcent constituents
found in F001, F08&F003, F004, and F005
wastes are currently burned as fuel. The
Agency believes that spent solvents,
even those containing high
concentrations of metals, can be safely
burned in industrial furnaces, and some
boilers, if these facilities meet
regulations, that EPA is now developing.
However, these new regulations may
influence the quantity and
characteristics of hazardous wastes
currently used as fuel. Because the
Agency is uncertain to what extent
solvents will be used as fuel under the
new requirements, to determine
capacity requirements, EPA is assuming
that no solvent wastes banned from
land disposal will be directed to fuel
substitution.
The data indicate that organic liquid
waste containing halogenated solvents
are equally likely to be distilled as
incinerated. Data also show that organic
liquids containing nonhalogenated
solvents are not as frequently distilled
for reuse as are halogenated solvents.Jn
general, the resale value of halogenated
solvents is higher than that of
nonhalogenated solvents. Therefore, in
order to estimate the total quantity of
organic liquid waste that is amenable to
each alternative technology, EPA
assumes that approximately half (when
considering rounding of decimals) of all
halogenated organic liquids will be
incinerated and about half will be
distilled. EPA is also assuming that two-
thirds of nonhalogenated organic liquids
will be incinerated and one-third
distilled.
Based on this analysis, the organic
liquids that will be incinerated annually
include 5.5 million gallons of
halogenated solvents and 6.5 million
gallons of nonhalogenated solvents, for
a total of 12.0 million gallons of organic
liquids. The organic liquids that wul be
distilled each year include 5.4 million
gallons of halogenated solvents and 3.2
million gallons of nonhalogenated
solvents, for a total of 8.9 million
gallons.1* The Agency recognizes that
these are only estimates and requests
information and comment that support
these or alternative estimates.
c. Organic sludges and solids. As
stated in Unit V.H.I, EPA estimates that
7.3 million gallons of organic sludges
and solids currently are land disposed
per year. These sludges and'solids
contain greater than 1 percent total
organics and greater than 1 percent total
solids. In addition, 1.9 million gallons of
wastes generated by small quantity
generators Eire organic sludges and jwill
compete for alternative capacity with
currently land disposed organic sludges.
Also, 1.2 million gallons of still bottoms
will be generated by distillation of the
organic liquids discussed in the previous
unit Therefore, a total of 10.4 million
gallons of organic sludges and solids-
require alternative capacity.' Of this
quantity, EPA is assuming that 7.2
million gallons of organic sludges and
solids contain primarily halogenated
organic constituents and 3.2 million
gallons contain nonhalogenated *
constituents.
13 EPA estimates that 1.2 million gallons of still
bottoms will be generated by distilling this waste.
Capacity for treating still bottoms is considered
under organic sludges and solids.
Organic sludges and solids are
amenable to both incineration and use
as a fuel substitute. Blending of still
bottoms for use as a fuel in industrial
boilers or furnaces is recognized as a
common disposal method for these
wastes and is widely practiced. As
stated before, EPA is confident that
many industrial furnaces, and some
boilers, can burn spent solvents, even
those containing high concentrations of
metals, when using control technologies
required to meet the 'new rules that the
Agency is currently developing.
However, for the reasons given in the
previous unit EPA is assuming that no
wastes banned from land disposal will
be used as fuel substitutes. EPA is
assuming.that all of the organic sludges
and solids, 3.2 million gallons of
nonhalogenated and 7.2 million-gallons
of halogenated organic solvents, will be
incinerated. Therefore, a total 10.4
million gallons of organic sludges and
solids require incineration capacity.
d. Inorganic sludges and solids. As
given in Unit V.H.I, 6.7 million gallons of |
inorganic sludges and solids are
currently land disposed. These wastes
consist of (1) soils contaminated with
solvents, and (2) sludges and solids
containing less than 1 percent total
organics and greater than 1 percent total
solids. Although EPA estimates that
soils contain between 1 percent and 7
percent organics, EPA believes that
those surveyed in the RIA Mail Survey
considered any soil contaminated with
solvents as an inorganic solid.
EPA estimates that these inorganic
sludges and solids contain
concentrations of solvents too low to
allow these wastes to be distilled or
reused as fuel. The Agency has
determined that the only treatment
option for the 6.7 million gallons of
inorganic sludges and solids
contaminated with solvents is
destruction by incineration. Although
the concentration of this waste is too
low to incinerate alone, it can be co-
fired with waste of higher heat value. A
potential secondary option for treatment
of these wastes is encapsulation by
chemical fixation or solidification
processes-However, the-Agency has too .
little information on the applicability of
encapsulation to solvent wastes to
estimate the quantities of wastes that
might be treated by this technique.
e. CERCLA wastes. Estimating
capacity demands of CERCLA waste is
difficult for several reasons. First few
data are available to describe CERCLA
waste in sufficient detail to determine
its treatability. Secondly, the Agency
has no way of predicting whether
wastes removed from future site
-------
173O
Federal Register / Vol. 51, No. 9 / Tuesday, January 14. 1986 / Proposed Rules
EPA requests comments on a 1-year
variance, and a corresponding effective
date of November 8,198?. Some
facilities probably could be completed
before this date, and those owner/
operators who could not complete their
facilities could apply for a case-by-case
extension. If EPA granted a 1-year
variance, however, the Agency probably
would receive far more applications for
extensions, and more resources would
be required to process these
applications.
7. Acceptance of Applications for Case-
by-Case Extensions
The Agency believes that applications
for case-by-case extensions will require
at least 6 months to process. Therefore,
EPA recommends that applications be
submitted as soon as possible in order
to prevent a lapse in the period of time
during which the applicant may land
dispose and store his waste.
VI. Proposed Treatment Standards for
Dioxin-Containing Wastes
A. Introduction
1. Summary of Congressional
Mandate—Land Disposal Restrictions of
Dioxin-Containing Hazardous Wastes
According to section 3004(e) of RCRA,
effective 24 months after the date of
enactment, further land disposal of
certain dioxin-containing wastes is
prohibited unless EPA determines that
such prohibition is not necessary in
order to protect human health and the
environment (42 U.S.C. 6924(e)}. If the
Agency fails to meet this deadline, these
wastes will be banned automatically
from further land disposal as of
November 8.1986. Section 3004(e)
addresses the dioxin-containing EPA
Hazardous Wastes, EPA Hazardous
Wastes Nos. F020, F021, F022, and F023
as referred to in EPA's proposed rule
published in the Federal Register of
April 4,1983 (48 FR14514). EPA issued
the dioxin listing as a final rule on
January 14,1985 (50 FR 1978) and
modified the numbering ofrthe new
listing, without making substantive
changes to the constituents covered. The
final listing specifically identifies
dioxin-containing wastes of F02O, F021,
F022, F023, F026, F027, and F028. The
listing describes an interim regulatory
regime with respect to land disposal,
pending further evaluation under the
land disposal restrictions program
which explores whether dioxin-
containing wastes should be restricted
from land disposal.
In light of the congressional mandate,
EPA is proposing in today's action to
regulate further land disposal of the
following dioxin-containing hazardous
wastes: EPA Hazardous Waste Nos.
F020, F021, F022, FQ23, F026, and F027.
F028'is a treatment residual from
incineration or thermal treatment of
dioxin-containing soil to six 9s DRE and
therefore is not addressed in this
proposal. The Agency is proposing to
establish screening levels for the
constituents of concern in the listed
dioxin-containing hazardous wastes
using the modeling approach described
earlier. These constituent levels which
are determined to be protective of
human health and the environment
represent maximum allowable
concentrations for individual
constituents in extracts (leachates) of
dioxin-containing hazardous wastes
which are determined to be protective of
human health and the environment.
2. Description of the Dioxin-Containing
Hazardous Waste Listing 14
The dioxin listing designated certain
wastes containing the tetra-, penta-, and
hexachlorinated dioxins and
diabenzofurans and certain chlorinated
phenols as acute hazardous wastes (50
FR 1978). This rulemaking also specified
certain management standards for these
wastes.These wastes are listed as acute
hazardous wastes (except F028: residual
from six 9s DRE for incineration of
dioxin-contaminated soils, which is
listed as toxic) because they contain
tetra-, penta-, and hexachlorinated
dibenzo-p-dioxihs and dibenzofurans. In
addition, these-wastes contain tri-, tetra-
and pentachlorophenols and their
derivatives. The dioxin-containing
waste listing is as follows:
F020—Wastes (except wastewater and
spent carbon from hydrogen chloride
purification) from the production and
manufacturing use (as a reactant,
, chemical intermediate, or component
in a formulating process) of tri-, or
tetrachlorophenol or of intermediates
used to produce their pesticide
derivatives. (This listing does not
include wastes from production of
hexachlorophene from highly purified
2,4,5-trichlorophenol.)
F021—Wastes (except wastewater and
spent carbon from hydrogen chloride
purification) from the production or
manufacturing use (as a reactant,
chemical intermediates, or component
14 The following acronyms and definitions are
used: PCDDs—all isomere of all chlorinated
dibenzo-p-dioxins. CDFs—all isomera of all
chlorinated dibenzofurans. CDFs—and CDFs—all
isomere of tetra-, penta-, and hexachlorodibenzo-p-
dioxins and-dibenzofurans, respectively. TCDDs
and TCDFs—all isomere of the tetrachlorodibenzo-
p-dioxins and-dibenzofurans, respectively. TCDD
and-TCDF— the respective 2,3,7,8-isomers. The
prefixes Tr, T, Pe, and Hx denote the tri-, tetra-.
penta-, and hexachlorodioxin and -dlbenzofuran
congeners, respectively.
in a formulating process) of
pentachlorophenol, or of
intermediates used to produce its
derivatives.
F022—Wastes (except wastewater and
spent carbon from hydrogen chloride
(purification) from the manufacturing
use (as a reactant, chemical
intermediate, or component in a
formulating process) of tetra-, penta-,
or hexachlorobenzenes under alkaline
conditions.
F023—Wastes (except wastewater and
spent carbon from hydrogen chloride-
(purification) from the production of
materials on equipment previously
used for the production or
manufacturing use (as a reactant,
chemical intermediate, or component
in a formulating process) of tri-, and
tetrachlorophenols. (This listing does
not include wastes from equipment.
used only for the production or use of
hexachlorophene made from highly
purified 2,4rs,-trichlorophenol.)
F028—Wastes (except wastewater and
spent carbon from hydrogen chloride
purification) from the production of -
materials on equipment previously
used for the manufacturing use .(as a
reactant, chemical intermediate, or
component in a formulation process)
of tetra-, penta-, or hexachloro-
benzenes under alkaline conditions.
F027—Discarded unused formulations
containing tri-, tetra-, or
pentachlorophenols, or compounds
derived from these chlorophenols.
(This listing does not include
formulations containing
hexachlorophene synthesized from
prepurified 2,4,5-trichlorophenol as
the sole component).
F028—Residues resulting from
incineration or thermal treatment of
soil contaminated with EPA
Hazardous Wastes Nos. F020, F021,
F022, F023, F026, and F027.
The wastes covered by the listing
include reactor residues, still bottoms, '
brines, spent filter aids, spent carbon
from product purification, and sludges
from wastewater treatment. Also
included are residues from managing
(i.e., treating or storing, or disposing) of
any of these wastes. Soils contaminated
with these wastes are also regulated
since soils contaminated by spills of
listed hazardous wastes are defined as
hazardous wastes (50 FR 28713, July 15,
1985). In addition, residues in containers
that contain any of the listed wastes are
covered unless the container has been
triple-rinsed with a solvent capable of
removing the waste or the container has
been cleaned by an alternative method
-------
Federal RegMtet / Vol. 51, No. 9- / Tuesday, January 14. 1986 / Proposed Rules
facilities is-operated privately. EPA does
not know the extent to which these
facilities will accept waste commercially
or be able to reclaim solvents from •
additional waste of their own. The
Agency solicits comment and
information in this area.
4. Comparison of Treatment and
Recovery Demand with Unused
Capacity
A summary of EPA's estimates of
quantities of solvent wastes requiring
treatment and recovery and the unused
commercial capacity per technology is
presented in the following Table 15:
TABLE 15.—COMPARISON OF ALTERNATIVE
TREATMENT AND RECOVERY DEMAND WITH
UNUSED CAPACITY
TABLE 15.—COMPARISON OF ALTERNATIVE
TREATMENT AND RECOVERY DEMAND WITH
UNUSED CAPACITY
OiaSon gallons per year]
Treatment or
recovery
technology
Wastowalar
treatment.,
Incineration:
Otganc
stodge* and
«"t»^*
Inorganic
sludges
andsofcfe..
Distillation —
Wast*
quantity
rsqaring
alternative
capacity
ias
22.4
a?
8.6
Unused
ca|Muty
<112
<256
(')
225
Capacity
shortlafl
>73
0
6.7
0
1 EPA « uauming ttiat none ot the <25.6 mitSon gallons
per'year of incineration capaaty is available to treat inorganic
sludge* and sofcl*.
The Agency believes that based on
the analysis of these data, sufficient
unused commercial recovery capacity
exists for all solvent wastes that will be
distilled. Commercial incinerator
capacity is insufficient to treat all
solvent wastes requiring incineration.
As explained in Unit Uf.E, when
capacity is insufficient to treat all of the
wastes groups requiring the same
technology. EPA will attempt to utilize
all of the available capacity by banning
the more toxic or coacentrated waste
first In this case, ii inorganic sludges
and solids (which are soils or contain
less than 1 percent total organics) are
excluded, incinerator capacity is
adequate to handle the wastes
containing the greater concentrations of
solvents (and total organics}.
Furthermore, EPA believes that the
estimated incinerator capacity
represents maximum capacity, and that
the actual difference between
incinerator capacity and the capacity
required by organic liquids, sludges, and
solids is insignificant Therefore, the
Agency concludes that a shortfall in
incinerator capacity exists for inorganic
sludges and solids. Current estimates of
commercial wastewater treatment
capacity also show a significant
shortfall for treating the estimated 185
million gallons of solvent-water
mixtures containing less than 1 percent
(10,000 ppm) that are currently land
disposed each year.
EPA is aware of recent news reports
citing possible closure of existing
commercial incineration capacity and
relatively high current utilization rates.
The Agency solicits comment on the
extent to which available capacity has
changed since EPA's most-recent data
collections.
5. Time Required To Develop
Alternative Capacity
Because capacity is insufficient for
solvent water mixtures and inorganic
sludges and solids, the Agency ha»
estimated the time to-provide
wastewater treatment,and incinerator
capacity, respectively, to treat these
wastes. EPA has conducted an in-depth
studyof the time required to provide
facilities to treat hazardous wastes (Ref.
64).
All new incinerators and some tank
treatment facilities require RCRA
permits to manage hazardous wastes.
The EPA study found that processing
time for RCRA permits for treatment
tanks, storage facilities, and incinerators
currently averages approximately 14
months, with a range of 4 months to 4
years. EPA believes that some new
facilities that treat solvent-water
mixtures in tanks will not require RCRA
permits because they will "fall under the
regulatory permitting exemption for
wastewater treatment tanks at 40 CFR
264.1(g)(6j.
The permitting time that may be
required by new treatment facilities
includes permits under the National
Pollutant Discharge Elimination System.
Many facilities that need to build
wastewater treatment facilities to meet
the land disposal restrictions will
already have NPDES permit limits
established for the wastes that are
currently treated in surface
impoundments. EPA does not require
that these NPDES-permitted facilities
obtain approval to change their
treatment process unless effluent
concentrations or discharge rates
change (delegated States may have
different requirement*}. Most
incinerators will generate scrubber
water, which will require treatment and
subsequent discharge under NPDES.
According to EPA's study, the EPA and
delegated States currently require 6
months to 1 year to process discharge
permits under the NPDES.
la addition to permitting, the EPA
study found that a facility designed for |
steam stripping or carbon adsorption,
two common methods of treating solve
wastewaters, will require 1 to 3 yean
(on average) to solicit and review bids, |
finance, design, construct, and test
depending on the size of the facility. Fo
instance, a 1,200 gallons per day I
steam stripping facility will require 1
stet to one and a half years to complet
these steps, whereas a 4,800 GPD unit
will take as long as 3 years. Various
types of incinerators take approximate!]
3 to 5 years to complete the necessary
steps (e.g., financing, design,
construction, and testing), depending on
size and other factors.
In summary, EPA data show that in
some cases a minimum of 1 year (i.e., fo
facilities that already have necessary
permits or are exempt from RCRA
permitting) is required to provide
wastewater treatment capacity for
solvent-water mixtures, although in
other cases 2 to 3 years are required.
EPA is unable, however, to determine 1
what extent less than 2 years are*
needed to provide wastewater treat
capacity. Therefore, the Agency believe
that 2 years is the best estimate of the
time to provide wastewater treatment
capacity. It appears unlikely that
additional incinerator capacity can be
developed within 2 years, since the tot
time required to provide an incinerator
averages 4 to 6 years.
6. Effective Date for Land Disposal
Restrictions
Based on the Agency's determination |
of available alternative capacity and I
time to provide additional treatment
capacity, the Agency believes that a full I
2 years are required to provide sufficient]
tank treatment capacity for solvent-
water mixtures. These wastes are
defined as aqueous wastes containing
less than 1 percent (10,000 ppm) of total
organic constituents and less than 1
percent total solids. In addition,
insufficient incinerator capacity exists
to treat inorganic sludges and solids.
These wastes consist of (1) soils, and (2) |
sludges and solids which contain less
than 1 percent total organic carbon and
greater than 1 percent total solids.
Therefore, EPA is proposing to grant a |
2-yeas variance to the effective date of
the land disposal restrictions for these
two categories of waste. Under this
proposal, the treatment standards
discussed in Unit V.G. will become
effective November 8,1988. Owner/
operators who cannot complete their
facilities by this date can apply for a
case-by-case extension described in
Unit IH.F.
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1732
Federal Ragater / Vol. 51. No. 9 / Tuesday, January 14, 1986 / Proposed Rules
windblown dust, water-rahoff, erosion
or flooding of waste disposal sites will
minimize human health hazards as. well
as environmental contamination during
handling and disposal.
6. Contamination of Soil, Ground Water,
and Streams
Contamination of soil, ground water,
and streams from the constituents of
concern in dioxin-containing wastes has
occurred at several uncontrolled sites.
Most of the damage incidents described
below focused on environmental
pollution by TCDDs. However, it is
reasonable to assume that TCDDs are a
marker substance for the CDDs and
CDFs. Hazardous wastes, including
organic solvents and wastes from the
production of chlorophenols, were
disposed at the Hyde Park landfill near
Niagara Falls, New York, from 1953 to
1975. The landfill is estimated to contain
about 120 kg of TCDD. A breach in the
landfill contaminated a stream, which
runs past the landfill, with organic
residues, including TCDD at an average
concentration of 70 ppb. At the Love
Canal landfill in Niagara Falls, New
_Xork,wa|tesi_containing CDps and
chlorophenols were disposed from 1942 *
to 1953. Numerous natural drainage
features and three storm sewers
underlie the area. TCDDs and
chlorophenols have migrated into the
environment, resulting in contamination
of soil and sediment at a considerable
distance from the dump site.
Environmental contamination has also
occurred at a facility in Jacksonville,
Arkansas, where 2,4,5-TCP/2,4,5-T/2,4-
D were produced. Several thousand
drums of toluene still bottoms were
improperly disposed. The drums
corroded over the years and their
contents contaminated soil, sediments of
two nearby streams, and fish and
aquatic life with TCDD.
While these damage incidents and
others (Ref. 103a) demonstrate that the
toxic constituents in dioxin-containing
wastes can migrate from the waste, that
they persist in the environment, and can
become part of the food chain, thereby
TABLE 16
posing a threat to human health when
disposed in an uncontrolled manner,
they are not representative of what is
likely to occur under current regulations.
The management requirements specified
in the dioxin listing rule are designed to
ensure as far as practically possible that
these wastes are properly managed in a
land disposal situation. However, these
requirements alone may not ensure that
land disposal is protective of human
health and the environment for as long
as these wastes remain hazardous.
B. Screening Levels For The
Constituents of Concern in the Listed
Dioxin-Containing Wastes
In today's action, the Agency is
proposing to establish screening
constituent levels for the dioxin-
containing hazardous wastes, EPA
Hazardous Waate Nos. F020, F021, F022,
F023, F026, and F027, using the modeling
approach described in Unit III.A. The
chemical-specific inputs to the model
are included in the following Table 18:
• Constituent
2.3.7,a-TCDD.
Other TCDDs
Other PeCDDs " ~
2.3,7.8-HxCDDs . . .
2,3.7.8-TCDFs "
Other TCDFs
2.3,7,8-PeCDFs
Other PsCDFs """
2.3.7,8-HxCOFs _.
2,4.5-Trichtofophenol
2,4,6-Trichlorophenol
PentaclHorophenol ~
Reference
dose (mg/1)
0.0018
0.3S
1.05
Proposed TEF
0.01
0.5
0.04
0.0004
0.1
0.1
0.01
0.0001
Percent
apportioned
to water
100
100
100
100
100
100
100
100
100
25
25
Health-based
reference
2X10"' mg/1
4x10-'° mg/1
5x10'' mg/1
5x10-' mg/1
2MO-' mg/1
2X10-" mg/1
2x10-' mg/1
2x10-« mg/1
0.0016 mg/1
0.09 mg/1
0.25 mg/1
Hydrolysis
rate
0
0
0
0
0
0
0
0
0
0
0
0
Screening level
4x10-' mg/1
4y 10x7mg/1
8x10-»mg/1
8x10"' mg/1
1x10"' mg/1
1X10'S mg/1
4x10-» mg/1
4x10"' mg/1
4x10-' mg/1
4x10'7 mg/1
4X10-" mg/1'
0.04 mg/1
2 mg/1
2 mg/1
Note.— in the absence of hsomer specific analytical data, it should be assumed that all isomers are 2.3.7,8 substituted.
) x (70 kg) / (2 1/day)=2x10-» mg/
The reference dose for each of the
CDDs and CDFs (the starting point of
the back calculation procedure) are
based on an evaluation procedure
developed by the Agency's Chlorinated
Dioxins Work Group to assess the
toxicity of these constituents (Ref. Ilia).
In this procedure, toxicity factors for the
CDDs and CDFs are based on an
evaluation of the potency of the various
CDD and CDF isomers and congeners in
a range of systemic and biochemical
effects. Data from experiments on
cancer induction, reproductive effects
arid biochemical effects were used for
this purpose. These data were
normalized to the potency of 2,3,7,8-
TCDD, the most toxic congener. Table
16 lists the toxicities (Toxicity
Equivalent Factor, TEF) of CDDs and
CDFs relative to 2,3,7,8-TCDD and the
health-based reference for each of the
constituents of concern in the listed
dioxin-containing wastes. The health-
based references (Table 16, column 4)
were derived by applying the TEFs to
the 10 « risk specific dose for 2,3,7,8,
TCDD. The proposed screening levels
(Table 16, column 7) were derived by
applying the ground water model
attenuation factor to the health-based
reference point, except in the case of
pentachlorophenol, where the
application of the surface water model
attenuation factor results in a more
stringent screening level. These values
represent the maximum concentration of •
each constituent in extracts of these
wastes that are acceptable for land
disposal.
C. Analysis of Treatment Technologies
for Dioxin-Containing Wastes and
Determination of BOAT
1. Applicable Treatment Technologies
The Agency, with the promulgation of
the dioxin listing rule, has established
specific management standards for
dioxin-containing wastes. With respect
to treatment, the Agency has established
standards for incineration and certain
thermal treatment The dioxin listing
rule states that incinerators burning the
listed CDD/CDF-containing wastes must
achieve a destruction and removal
efficiency of six 9s in addition to the
other standards contained in § 264.340
(Subpart O). The rule specifies that the
six 9s DRE will be measured on a
surrogate Principal Organic Hazardous
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Faderal Register-/ Vol. 51. No. 9-/" Tuesday. January 14. 1966 / Proposed Rules
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^*^*^^^^^MB^E^PiMBMslMB»MBMMBBBii^MBMM^^MMBBBBBBMBBi^Mi^MM^»^^^aMMMMMMM^^M«a^^^^^M
shown to achieve equivalent removal '
(See 40 CFR 28L7[bJ(3)J.ls
3. Summary of Regulations Affecting
Land Disposal oFDioxin-Containihg
Wastes
In the dioxin listing rule, EPA also
specified additional management
standards relating to land disposal of
these wastes. Specifically, the Agency
prohibited the management of the listed
dioxin-containing.wastes at interim
status land disposal facilities and
required land disposal facilities
intending to manage these wastes to •
submit a waste management plan to
address the additional design and
operating measures over and above
those in Part 264 which the facility
intends to adopt in order to prevent
migration of the waste or waste
constituents. (There are exceptions for
interim status surface impoundments
holding wastewater treatment sludges
that are created in the impoundments as
part of the plant's wastewater treatment
system and interim status waste piles
• that meet the requirements of
§ 264.250(c).) The plan is to be submitted
by the owner or operator of the disposal
facility as part of the Part 284 permit
application and should address the
following factors:
a. The volume, physical, and chemical
characteristics of the wastes, including
(heir potential to migrate through soil, to
volatilize or otherwise excape into the
atmosphere.
b. The attenuative properties of
underlying and surrounding soils and
other materials.
c. The mobilizing properties of other
materials co-disposed with these
wastes.
d. The effectiveness of additional
treatment, design, or monitoring
techniques.
The Agency believes that such a.
waste management plan will help.
provide assurance that these .wastes are
properly managed in a land disposal '
situation.
The exception for management at
surface impoundment»in which
wastewater treatment sludges are
generated was based on pragmatic as
well as environmental considerations. If
the Agency banned all interim status
impoundments from managing these
wastes, facilities generating wastewater
treatment sludges in impoundments
would have to halt the manufacturing
process and obtain a permit for new
"If the container is cleaned, the container is
considered empty and no longer subject to the
regulation. However, the rinsate that is generated is
rin acute hazardous waste and. thus, subject to
regulation (45 FR 78528. November 25.1BSO).
capacity before they could manage these
wastes. The Agency determined that the
short-term management of these sludges
in interim status impoundments could be
protective, since the sludges will absorb
the CCDs and CDFs and since other
potentially mobilizing organics will be
present in the wastes at low
concentrations due to dilution and
biological treatment. In the case of
interim status waste piles meeting the
requirements of § 284.250(c), the Agency
determined that such waste presents a
minimal and acceptable risk because the
pile is inside a structure that provides
protection from precipitation, run-on,
' and wind dispersal, does not generate
leachate. and does not contain free
liquids.
4. Quantity of Dioxin-Containing Waste
Generated
Approximately 14.7.million pounds
(6,650 metric tons) of dioxin-containing
wastes are presently covered by the
dioxin listing rule (Ref. 67). These
wastes are-primarily associated with the
past production and manufacturing use
of tri- and tetra-chlorophenol and
current manufacturing uses of
pentachlorophenol. These quantities are
estimates and will be revised as more
information becomes available. The
recent dioxin listing rule will provide the
Agency, through its reporting
requirements, with the universe of
facilities that generate, transport, treat,
store, and dispose of dioxin-containing
wastes and the amounts generated and
managed (40 CFR 262.41, 264.75, and
265.75). For the purpose of this proposal.
. however, the Agency is relying on
available data presented above.
(Additional information on quantity
estimates of dioxin-containing wastes
can be found in the public docket for
this proposal (Ref. 67).
The Agency is investigating through
its Superfund program and the "Dioxin
Strategy" (Ref. 103) the extent of dioxin
contamination in the U.S. When these
investigations are complete. EPA wilt be
able to determine more accurately the
total volume of contaminated soil
covered by the rule. In the interim, an
assessment of the extent of dioxin-
contaminated soil can be made by
assessing estimates made in the State of
Missouri. Indications are that an
estimated 1.1 billion pounds (500,000
metric tons} of dioxin-contaminated soil
exist in Missouri with an estimated 350 .
million pounds (160,000 metric tons) of
soil at Times Beach alone (Ref. 67). For
purposes of this proposed rulemaking,
the Agency is assuming that 1.1 billion
pounds of dioxin-contaminated soil
exist in the country, until the results of
other EPA studies can be evaluated.
5. EPA Concerns With Land Disposal of]
Dioxin-Containing Wastes
The constituents of concern in these
wastes are CDDs, CDFs, tri-, tetra-, and]
pentachlorophenols,.andchlorophenoxy
derivatives of these chlorophenols.
CDDs and CDFs are among the most
potent toxic substances known. TCDD
and a mixture of two H* CDDs are
among the most potent animal
carcinogens tested. These substances
are also potential human carcinogens.
TCDD has also been shown to be
teratogenic, fetotoxic and embryotoxic
at very low doses. Many CDDs and
CDFs are acute toxicants at the ug/kg/
day dose rate and, even at these very-
low concentrations, are inducers of the
liver's enzyme system (Ref. 103a).
CDDs and CDFs are persistent in the
environment. Bio-degradation and
hydrolysis decay mechanisms are not
likely to be significant Additionally,
several of the constituents of concern -
can accumulate in the food chain. The
estimated bio-accumulation factor (BCF)|
for TCDD is approximately 5,000 to I
and structure activity considerations
make it reasonable to assume that the
BCF for other CDDs and CDFs is similar.l
These are some of the highest BCFs
known. The calculated BCF for the
chlorophenols ranges from 290 for 2,4,5- |
TCP to 610 for 2,4.6-TCP. Thus,.if these
constituents migrate from these wastes, |
even hi extremely low concentrations,
they can accumulate in biological
organisms at much higher levels.
Investigations have documented the
extreme immobility of TCDD in most
soils and its low solubility in water.
Given their physiochemical similarities,
the other CDDs and CDFs are expected
to be immobile hi soils and water
insoluble. However, these constituents
are likely to be more mobile in
situations where they are co-disposed
with solubilizing solvents or in
situations in which soil binding sites are
exhausted. A recent study determined
that chloro-organic contaminants in
wastes, other than TCDD, may be more
significant than soil properties in
controlling solubility and movement of
TCDD in contaminated soil, once the
absorptive capacity of the natural
organic compounds (i.e., humic acids)
has been exhausted (Ref. 63). However,
CDDs and CDFs are not expected to
leach to ground water and percolate
through soils if proper precautions are
taken to prevent co-disposal with
solubilizing solvents.
In addition, the waste management
plan helps provide assurance as far as is
practically possible that contamination
of air and surface water as a result of
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1734
Federal Register / VoL 51. No. g / Tuesday. January 14, 1986 / Proposed Rules
wastes except dioxin-containing
wastes). The efficiency of incineration
of dioxin-containing wastes has been
demonstrated full-scale by the
successful dioxin burn at six 9s DRE in
the EPA Mobile Incineration System at
the Denney Farm Site in McDowell,
Missouri and the incineration of PCB
wastes at six 9s destruction at a number
of facilities. Data have recently been
collected on incineration residues that
were generated during the field
demonstration of the MIS (50 FR 23721,
June 5,1985). These residues included
the process wastewater, the rotary kiln
ash, the filter media generated from a
cleanable high efficiency air Filter
(CHEAP) participate scrubber, and other
solids removed from the wastewater.1'
Analytical data on the organic
constituents in the incineration residues
from six 9s DRE showed no detectable
levels of CDDs/CDFs in the filtered
scrubber water, kiln ash, or CHEAP
residue by routine analytical methods.
Although no detectable levels of CDDs
and CDFs were found in the residuals
from the MIS trial burn, the actual
concentrations of CDDs and CDFs in
these residues are likely to be much less
than the maximum possible
concentrations projected from detection
limits. Most of the analyses were
performed in accordance with the
methods specified in SW-846 (Ref.
120a). However, these methods,
developed for routine use, are not
designed to achieve extremely low
detection limits. When a research
analytical method was applied to the
ash, a fifty-fold reduction in the
detection limit was achieved.
Preliminary results using this method
show that the ash residues are likely to
contain no more than 4 ppt of TCDD
equivalents (i.e., a fiftieth of the
maximum concentration projected from
detection limits). With respect to the
aqueous waste, the estimated maximum
concentration of CDDs and CDFs (6 ppt
based on detection limits}, in the
wastewater, probably overestimates the
concentration by a factor of 50. Thus, a
more realistic estimate for the
concentrations of CDDs and CDFs in the
wastewater would be about 0.1 ppt.
The data from the MIS burn show that
residues resulting from the incineration
e of CDDsrand CDFs at sixj?s;DRE contain^
these toxicants at concentrations about
five to seven orders of magnitude less
than those in the starting material. Thus,
solid residues resulting from
incineration at six 9s DRE of dioxin-
containing wastes containing 10 ppm
TCDD may be expected to contain less
than .1 ppb TCDD.17 As stated in the
delisting petition for the MIS (50 FR
23721, June 5,1985), it is the Agency's
usual practice to use the detection limit
as the possible upper level exposure
limit for purposes of hazard evaluation
when a constituent is not detected. For
example, the detection limits for the
TCDDs in wastewater was reported at
0.98 to 3.9 ppt. Therefore, TCDDs could
be present in the filtered scrubber water
in concentrations up to 3.9 ppt.
Because CDDs and CDFs are of
similar incinerability (heats of
combustion) to PCBs, it is reasonable to
expect that incineration of these
constituents at similar initial waste
concentrations would result in similar
residual concentrations to PCBs. Data
are available on PCB and CDD/CDF
concentrations in treatment residuals
from several incinerators burning
industrial chlorinated wastes, PCB
wastes, and dioxin-containing wastes
(Ref. 103a). These data demonstrate that
an incinerator operating at six 9s DRE
can achieve extremely low
concentrations of CDDs, CDFs, and
PCBs in the treatment residuals.
According to these data; incinerator
scrubber water from the treatment of
chlorinated industrial wastes, contain
less than 0.001 ppb of various CDD
congeners. Also, PCB incineration at six
9s DRE results in residual
concentrations 0.01 to 0.2 ppb of PCB in
the ash to 0.01 to 50 ppb PCBs in other
residuals.
The Agency has evaluated
performance data for the incineration of
dioxin-containing wastes at six 9s DRE.
This treatment is the only
"demonstrated" technology for these
wastes. The Agency has concluded that
incineration to six 9s DRE substantially
dimishes the toxicity of dioxin wastes
subject to this rule, and minimizes short-
term and long-term threats to human
health and the environment from those
" The other solids include participates collected
from the secondary combustion chamber and sludge
which is collected from the air pollution control
equipment sumps and from the clarifier on the
process waterpurge stream threatment system. The
carbon filters are not included in the other solids
category and h»nce are not a subject of this notice.
17 Concentrations of CDDs and CDFs in the
residue equals the amount in the waste feed tunes
the fraction remaining—10 mg/kg X 10" ng/mg X
(10-' to 10-8 reduction) = 1 to 100 ng/kg = 1 to 100
ppt. This estimate assumes that the net formation of
CDDs and CDFs in the course of incineration is
negligible. This assumption is warranted because
the conditions necessary to ensure six 9s DRE are
presumably consistent with conditions to minimize
the formation of products of incomplete combustion.
wastes that may remain after treatment.
As previously discussed in Unit ffl B.,
EPA considers treatment methods to be
substantial if they result in
nondetectable levels of hazardous
constituents of concern in residuals.
Therefore, best demonstrated
achievable technology for treating
dioxin-containing wastes subject to the
land disposal restrictions consists of
incineration to six 9s DRE.
D. Comparison of BOAT and Screening
Levels and Establishment of Treatment
Standards
1. Comparison of BOAT and Screening
Levels
The Agency has determined that the
only sufficiently demonstrated
technology for the treatment of dioxin-
containing wastes is incineration.
However, the agency cannot exclusively
state that incineration to six 9s DRE will
achieve the screening levels for the
CDDs and CDFs because these levels
are below those which can be detected
using standard EPA methods. The
detection limit for the CDDs and CDFs
in waste extracts analyzed, using
method 8280 specified in SW-846, is 1.0
ppb (Ref. 120a). Current analytical data
indicate that residual concentrations for
the CDDs and CDFs from the
incineration of dioxin-containing wastes
will be far below that detectable by
standard EPA analytical methods (50 FR
23721, June 5,1985). Therefore, the
Agency is using the detection limit to
establish the treatment standard under
proposed § 268.42.
2. Treatment Standard for Dioxin-
Containing Wastes
Under today's proposal, wastes
identified by the hazardous waste
listings as F020. F021, F022, F023, F026,
and F027, must be treated to a level
below the detection limit if there are any
detectable levels of the CDDs and CDFs
in the extracts of the wastes prior to
their being disposed in a RCRA Subtitle
C land disposal facility.18. However,
wastes exceeding the detection limit can
only be treated in accordance with the
criteria for incineration as specified
under 40 CFR Parts 264.343 and 265.352
in the dioxin listing rule. The Agency
believes that such treatment in
combination with the management
requirements specified in the dioxin
18 Revisions to RCRA method 82BO specified in
SW-846 may result in a lowering of the current
detection limit. For example, if the method is
revised and the detection limit is lowered from the
current limit of 1.0 ppb to 1.0 ppt. this new detection
limit will become the level at which wastes will be
banned from land disposal.
-------
Federal Register / Vol. 51, Nou9 / Tuesday.-January 14. 198& / Paopoaed Rules.
173$-
Constituent that is more difficult to
incinerate than the particular CDDs or-
CDFs contained in the waste.
The Agency uses heat* of combustion
(HC) as its incinerability hierarchy: the
lower a compound's heat of combustion.
Ihe more difficult it is to incinerate. For
example, using the heats of combustion
hierarchy, the incinerability of a waste
containing HxCDD would be tested
using a POHC with a heat of combustion
less than 2.81 kcal/gm, perhaps, 1,1,1-
trichloroethane (HC=1.99 kcal/gm) (50
FR1992, January 14.1985) in order to
determine if a six 9s DRE was met. If an
incinerator proved a six 9s DRE on
pentachlprophenol. which has a heat of
combustion of 2.09 kcal/gm, it could
incinerate all the CDDs and CDFs,
covered by the dioxin listing rule, since
Ihe CDD/CDF compound most difficult •
to decompose (incinerate) is HxCDD.
The Agency acknowledges in the
dioxin listing rule that there are
presently a number of emerging thermal
treatment technologies that may be
applicable for the treatment of dioxin-
contaMng wastes in order to render
them non-hazardous (or at least, less
hazardous). Some of these technologies
are now thought to be practicable, while
some are in the pilot stage, and pilot-
scale field experiments need to be
performed: others are still in early •
research and development. In the
absence of RCRA permit standards.
such treatment units would not be
allowed. This would stifle and
discourage the development of new
treatment alternatives and the
development of innovative technologies
for the treatment of these very toxic
wastes. The Agency feels that such an
outcome is undesirable. As a result, the
dioxin listing rule allows for interim
status thermal treatment uriits to treat
the dioxin-containing wastes if it has
been certified that the units meet the
applicable performance standards in
§ 284.343 (including six 9s DRE for
POHCs).
The dioxin listing-rule impose certain
restrictions oni the treatment of dioxin-
containing wastes^Only those facilities
meeting the performance standards for
incineration or thermal treatment (i.e..
six 9s DRE) can manage these wastes.
Units which meet these specified
performance standards for incineration
and thermal treatment will be
considered applicable treatment for
dioxin-containing wastes.
Much research is currently being
conducted to develop and evaluate
treatment technologies applicable to
dioxin-containing wastes. Listed below
are treatment technologies that are in
one of three stages of consideration:
existing technologies being evaluated;
technologies being actively researched:
and technologies in the conceptual or
development phase (Ref. 8).
a. Technologies under evaluation:
i. Mobile incineration.
ii. High temperature, fluid-wall.
advanced electric reactor.
iii. Infrared heating.
iv. UV photolysis.
v. Underground surface mines as
repositories for dioxincontaminated.
soils.
vi. Thermal desorption of 2,3,7,8-
TCDD from contaminated soils,
vii. White rot fungus (Phaneracbaete
chrysosporium).
b. Current research:
i. Sorption/desorption of 2,3.7,8-TCDD
in contaminated soils.
ii. Mobility of 2,3,7,8-TCDD frorf soils
in water, methanol, methanol and
toluene liquid system.
iii. Bioavilability research.
iv. In-situ stabilization techniques.
c. Technologies in conceptual or
developmental Phase:
i. In-situ vitrification.
ii. Recirculating fluidized bed.
iii. Fluidized bed.
iv. Chemically modified clays.
v. Catalytic UV-ozone.
vi. Supercritical water.
vii. At-sea incineration.
Few data currently exist, however, on
the performance of these technologies
on all types of dioxin wastes. The
Agency is continuing to gather data and
information on these and other emerging
technologies in order to evaluate their
future potential as an applicable
treatment technology.
2. Demonstrated Technologies for
Dioxin-Containing Wastes
Incineration is the only technology
which has been fully demonstrated for
treating dioxin-containing wastes. A
field demonstration of EPA's Mobile
Incineration System (MIS) was recently
conducted on dioxin-containing wastes
(F02Q. F022, F023, F026. and F027) at the
Denney Farm Site in McDowell,
Missouri. This full-scale demonstration
was conducted in accordance with the
incineration- performance standards
specified in the dioxin listing rule, i.e.
six 9s DRE.
During the field demonstration at the
Denney Farm Site, various dioxin-
containing solids, liquids and soils were
incinerated. They included: CDD-/CDF-
contaminated soil, activated carbon,
drum remnants, miscellaneous trash,
asphaltic material, mixed solvents and
process wastes. The data indicate that
this full-scale mobile incineration unit,
operating at six 9s DRE is capable of
treating dioxin-containing wastes and
constituents subject to this rule.
Accordingly, EPA determines that unita
meeting the performance standards of
the dioxin listing rule (six 9s DRE) also
meet the "demonstrated" component of
the BOAT standard.
Another type of incinerator which
meets the "demonstrated" component of
the BOAT standard, are those units
burning polychlorinated biphenyls.
These incinerators are required to
operate under conditions that result in
six 9s destruction (40 CFR 781.70).
Similar DREs are expected to be
achievable for CDDs and CDFs in these
units, since PCBs and CDDs and CDFs
have similar degrees of incinerability
(heats of combustion). Consistent
destruction of PCBs to six 9s DRE has
been demonstrated full-scale at a
number of facilities (e.g., those of SCA.
Incorporated in Chicago, Illinois; Rollins
Environmental Services, in Deer Park,
Texas; the facilities operated by Energy
Systems Company in El Dorado,
Arkansas; and by the General Electric
Corporation in Waterford, New York).
The Agency has determined that
incinerators operating in accordance
with the performance standards
specified in 40 CFR 781.70 for PCB
wastes, namely six 9s destruction, also
meet the "demonstrated" component of
the BDAT standard.
3. Analysis of Relative Risk
( EPA has evaluated the potential risks
posed by incineration of a dioxin-
containing waste compared to the
potential risks posed by land disposal of
the same waste in a landfill. The Agency
determined that for the selected waste,
incineration posed a lower potential risk
than land disposal. The waste selected
for the analysis was an off-specification
pesticide product with 0.6 ppm TCDD
equivalents. Incineration is modeled
because it is the only demonstrated
treatment method for dioxincontaining
wastes. The Agency believes that the
risks presented by potential land
disposal and incineration of the selected
dioxin-containing waste are adequately
simulated in the modeling procedure. As
better data become available
characterizing additional dioxin-
containing wastes, the Agency will
include this information and expand its
evaluation.
4. Determination of BDAT
Currently, the only sufficently
demonstrated treatment technology for
dioxin-containing-wastes is incineration.
Incineration to six 9s DRE achieves
-lower concentrations of CDDs and CDFs
in the treatment residuals than
incineration to four 9s DRE (current
standard for all RCRA hazardous
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51. No. 9 / Tuesday. January 14, 1986 / Proposed Rufes
disposal at the levels specified in the
statute.
Congress incorporated the California
List into the provisions of the HSWA
primarily because the State of California
had conducted studies and initiated
rulemaking which demonstrate that
waste containing these constituents at
the designated concentrations may be
harmful to humans and the environment.
(S. Rep. No. 98-284, 98th Congress, 1st
Sess. 17 (1983).) Congress' intent hi
specifying threshold levels for these
constituents was to avoid time-
consuming litigation over the selection
of appropriate levels (H.R. Rep. No. 98-
198,98th Congress, 1st Sess. 35(1983).)
The Agency is authorized to establish
less stringent levels based on BDAT if
BOAT cannot achieve the levels
specified in the statute (or a more
stringent level that EPA may establish).
The Agency also may authorize land
disposal of the specified constituents at -
concentrations that are less stringent
than the level prescribed in the statute if
it is demonstrated through a petition
under section 3004(d) that less stringent
levels will be protective of human health
and the environment at a particular site.
The Act also provides EPA the
flexibility to substitute more stringent
levels, where necessary to protect
human health and the environment
under section 3004(d)(2). The Agency,
does not interpret this provision as
imposing an affirmative duty on the
Agency to initiate studies to determine
whether the statutory levels are
protective.
Although there is no affirmative duty
to do so, the Agency is re-evaluating the
California list constituent levels. EPA is
considering using the ground water back
calculation model to evaluate liquid
waste containing California list metals.
The MINTEQ component of the model
will account for variables such as
speciation of metals and dilution and
dispersion in ground water. The
halogenated organic compounds (HOCs)
category is more comprehensive and,
therefore, more difficult to evaluate than
the other California List categories.
Because of the diversity inherent in this
group of constituents (i.e., it includes
compounds which exhibit a wide range
of lexicological, chemical, and physical
properties), and the lack of data on
individual HOCs, the Agency is unable
to use the ground water model which is
constituent-specific in its evaluation.
Moreover, since HOCs are the only
category for which Congress specified
both liquid and solid wastes for
prohibition, the Agency must identify a
practical test method for determining the
content of these constituents in solid
hazardous waste. Therefore, the Agency
is soliciting comment on how to
ey.alua.te the specified levelfpr HOCs. If
the Agency cannot resolve the
difficulties with evaluating HOCs, it
may not re-examine the statutory levels.
The Agency anticipates proposing
treatment standards for the California
List constituents in approximately 6
months.
VIII. Relationship of the Part 268 Land
Disposal Restrictions Provisions To
Other Statutory and Regulatory
Requirements
A. Relationship to Other Statutory Ban
Provisions
The 1984 Amendments to RCRA
include several other provisions that
ban or restrict specific practices. These
provisions include: conditional
restrictions on the placement of
hazardous wastes in salt dome
formations, salt bed formations, and
underground mines and caves (section
3004(b)); restrictions on the disposal of
bulk and containerized liquid wastes in
landfills (section 3004(c)); a ban on the
use of dioxin-contaminated materials
and other hazardous wastes (except for
wastes identified solely on the basis of
ignitability) for dust suppression or
other road treatment (section 3004(1));
and a ban on underground injection of
hazardous waste into or above a •
formation which contains an
underground source of drinking water
within one-quarter mile of the well used
for the injection (section 7010(a)). Based
on the specific statutory language hi
section 3004 (b) and (c), determinations
' by the Administrator under section 3004
(d), (e), or (g) do not supersede the
statutory restrictions on placement of
hazardous wastes in salt dome and salt
bed formations and underground mines
and caves or the statutory restrictions
on liquids in landfills contained in
section 3004(c)(l). The language of
section 3004(m)(2) also indicates that
compliance with the section 3004(m)
treatment standards exempts wastes
only from prohibitions promulgated
under section 3004 (d), (e), (f), or (g).
Thus, compliance with section 3004(m)
does not provide an exemption from
restrictions on salt domes, salt bed
formations, and underground mines and
caves (section 3004(b)), or liquids in
landfills (section 3004(c)). Likewise, the
Agency interprets the statutory ban on
use of hazardous wastes for dust
suppression or road treatment and the
ban on certain injection of hazardous
waste as overriding any Agency
decisions under section 3004 (d), (e). (g),
or (m).
B. Relationship To Hazardous Waste
Identification Regulations
In 40 CFR 260.22, procedures are
identified for the submission of petitions
to amend 40 GFR Part 261 to exclude a
waste produced at a particular facility
from regulation as a hazardous waste
(i.e., to delist the waste). The Agency
recently amended these procedures in
response to additional requirements
imposed by HSWA (50 FR 28.702, July 15,
1985). Standards promulgated under
section 3004(m) are not an Agency
determination of the appropriate levels
for delisting. A delisting determination
is based on a finding that the waste
need not be subject to regulatory control
under Subtitle C of RCRA, but rather
that the waste can be safely managed in .
a Subtitle D facility. This is a different
determination than the Agency must
make an establishing treatment
standards. Treatment standards based
on health-based thresholds assure
protection of human health and the
environment when waste is managed in
a Subtitle C facility. Treatment
standards based on technology-based
levels assure that the mobility or
toxicity of the waste has been
substantially reduced.
The Agency will shortly propose a
new characteristic for identifying
wastes as hazardous—the Organic
Toxicity Characteristic. Under this
characteristic, wastes will be
determined to be hazardous if the
concentration of hazardous constituents
in an extract from the waste exceeds
specified levels. The approach being
used to determine the appropriate levels
of regulatory control in the Organic
Toxicity Characteristic is similar to the
approach being used by the Agency is
establishing health-based thresholds. In
developing regulatory levels for the
Organic Toxicity Characteristic, the
Agency will use a back calculation
procedure using fate and transport
equations hi much the same way as the
Agency is establishing health-based
thresholds. However, the scenario being
modeled for purposes of establishing
regulatory levels for the Organic
Toxicity Characteristic represents a
Subtitle D, non-hazardous waste facility.
Wastes containing constituents at
concentrations below the regulatory
levels for the characteristic can be
safely managed at a facility that does
not meet the engineering standards
required for Subtitle C facilities and thus
will not be identified as hazardous
wastes. In those cases where the section
3004(m) treatment standard is expressed
as a~leach concentration, the Agency is
proposing to use the same leach
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* Federal Register / Vol. 51. No. .9 / Tuesday.. January 14, 1986- / Proposed Rules
listing rule will help provide assurance
that these wastes are properly managed
in a land disposal situation. The
generator also has the option of treating
dioxin-containing wastes by
incineration to six 9s DRE rather than
first conducting the extraction
procedure.
The Agency acknowledges in the
dioxin listing rule that there are
presently a number of emerging thermal
treatment technologies that may be used
to treat dioxin-containing wastes in
order to render them non-hazardous (or
at least, less hazardous). Although these
f units have not yet been .demonstrated
' for all dioxin waste matrices or at full-
scale, for purposes of this proposal.
thermal treatment units certified as
• meeting the applicable performance
standards in 40 CFR 264.383 (including
six 9s DRE for POHCs in the waste) may
also be used as a treatment method
under RCRA section 3004(m).
E. Determination of Alternative
Capacity and Ban Effective Dates
1. Required Alternative Capacity for
Dioxin-Containing Wastes
As discussed in Unit VI.A.5, the actual
volume of wastes subject to the dioxin
rule are still being evaluated and
revised by the Agency. It is believed.
however, that the quantity of wastes
currently being generated that will be
subject to the dioxin rule amounts to 3
million pounds (1.350 metric tons) (Ref.
67). It is more difficult to assess the
quantities of waste that have been
stored over the years or those subject to
remedial or cleanup activities (including
contaminated soils), that fall under this
rule. The Agency believes that the latter
will create a larger demand on capacity
than the currently generated wastes. As
mentioned earlier, the Agency is
continuing to'evaluate the universe of
these wastes and will in the future be
better able to present actual volumes.
The Agency requests information and
data in this area to assist it with its
efforts.
2. Treatment Disposal and Recovery
Capacity Currently Available
Currently, there ia.no disposal or
recovery capacity for dioxin-containing
wastes. In addition, no incinerator or
other thermal treatment facility has
been approved by the Agency to treat .
dioxin-containing wastes. Although
several certification petitions have been.
received by the Agency, no incineration
or thermal treatment units have been •
certified/permitted as required under ,• •
the dioxin listing rule.
Interim status incinerators- that have
been approved under TSGA td burn
PCBs are a type of incinerator for which
the owner/operator may wish to apply
for certification. As pointed out earlier,
PCB incinerators are a logical choice to
burn these wastes because they are
required to meet the same performance
standard (six 9s DRE) required under
the dioxin listing rule, and PCBs in some
cases, are more difficult to incinerate
than CDDs and CDFs. There are
currently three commercial incinerators
approved under TSCA to burn PCBs. In
addition to these units, several other
incinerators under development may be
available (contingent on-certification)
for treating CDD/CDF-containing waste.
However, the Agency has no indication
whether or when any of these, or any
other facility will be certified to treat
dioxin-containing wastes.
The Agency has full confidence in the
safeguards provided by the required
management standards. EPA is
committed to move rapidly to assure
that approved capacity is available to
properly manage the listed dioxin-
containing wastes. Agency efforts in this
area include identification of facilities
that could properly manage dioxin
wastes, and encouraging owners and
operators to apply for the necessary
Federal, State, and local permits. The
EPA regional offices will work closely
with these facilties to expedite their
applications with the Federal, State and
local governments.
It is difficult to predict accurately,
however, when facilities will be on-line.
At the present time, however, no
facilities have been approved to dispose,
recover or thermally treat dioxin-
containing wastes, and for purposes of
this proposed rule, there is currently no
capacity available to meet the treatment
standards.
3. Time to Develop Capacity
The Agency anticipates that
certifications to burn dioxin-containing
waste will be issued in the near future.
It is difficult to predict, however, when
these certifications will occur. A review1
of past permitting actions indicates that
the length of time needed to obtain a
permit to operate a major hazardous
waste treatment facility can take as long
as 2 to 3 years. While the Agency
believes that certification of-existing
incinerators should not take as long as
permitting new facilities, no data exist
from which to determine the moat likely
time period for this certification to
occur.
4. Land Disposal Restriction Effective
Date
Section 3004(h)(2) indicates that EPA
need not establish the effective date of-
the land disposal restrictions
immediately, but can set the effective
date on the earliest date on which
adequate alternative treatment,
recovery, or disposal capacity will be
available. In this case, as has been
discussed in Unit VI.E.2, alternative
capacity is not currently available due
to the lack of treatment facilities
certified to destroy dioxin wastes.
Although it is not clear how long it will
take for a facility to obtain certification.!
EPA estimates that the process can take|
as long as 2 to 3 years. Accordingly, EP/
is proposing to grant the maximum 2-
year variance allowed under section
3004(h)(2). If a 2-year variance is
granted, the effective date for the land
disposal restriction decisions affecting
hazardous waste listings F020, F021.
F022, F023, F026 or F027 would be
November 18,1988. In the interim,
facilities will be required to manage
these wastes in accordance with the
requirements of the dioxin listing rule.
EPA will reconsider this effective dat
and will specify an earlfer date if, prior
to final.rulemakingr one or more
facilities that meet the treatment methodl
specified in Unit VLC.5 are certified by
EPA, and if the unused capacity of these |
facilities is sufficient to destroy the
quantity of dioxin wastes that are
subject to the land disposal restrictions.
Upon reconsideration, the Agency may
choose to grant a shorter variance (e.g..
1 year) or to make the ban effective
immediately upon final promulgation. .
F. Request for Comments
The Agency requests public comment
on all aspects of the approach outlined
in today's proposal. However, public
comment is especially requested with
respect to establishing incineration to
six 9s DRE as the treatment standard if
any detectable levels of CDDs or CDFs
are found in extracts of the listed
dioxin-containing wastes. Also, the
Agency solicits comment on the use of
method 8280 specified in SW-£46,(Ref.
120a). for determining if any dioxins are
present in extracts of dioxin-containing.,
wastes and requests information on
other appropriate methods which- could
be used for the same purpose.
VII. California List
As stated earlier, effective 32 months
after the date of enactment, further land
disposal of the California List
constituents-is prohibited unless EPA
determines that such prohibition is not
required to-protect human health and •
the environment (see Unit I.B.2 of
today's action). If the Agency fails to
meet this deadline, the wastes will be
banned automatically from further land
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Federal Register / Vet. 51, No. 9 / Tuesday. Januaiy 14. 1986 / Proposed Rules
On the other hand, under item 4
above, States, which have the authority
to impose bans may be authorized under
section 3006 to grant petitions for
exemptions from bans. This is because
the statutory language differs and
because decisions on petitions do not
require the same type of national
perspective as the decisions to ban
waste or grant extensions discussed
above. In accordance with section
3004(i), EPA will issue for publication in
the Federal Register notices of
authorized States' decision on petitions.
Notwithstanding any of the above
EPA actions. States are free to impose
their own disposal bans. Such bans may
be imposed by States because State
programs are permitted to be more
stringent or broader in scope than the
Federal program. (See section 3009 of
RCRA and 40 CFR 271.1(i).) Where
States impose bans of their own which
contravene an EPA action such as a
variance, extension or granting of a
petition, the more stringent State ban
would govern and the EPA action would
be without meaning in the State.
EPA will issue additional guidance on
State authorization regarding the above
issues.
X. Implementation of the Part 268 Land
Disposal Restrictions Program .
The requirements of the HSWA and
the resulting proposed regulations under
40 CFR Part 268 pertaining to land
disposal restrictions, when combined
with existing hazardous waste
management requirements, will make
the management of restricted wastes
(i.e., those wastes listed in Part 268
Subpart C) more complex than the
current management of hazardous
wastes. In most cases several options.
will be available for the management of
restricted wastes. In order to provide
direction to generators and-treatment
and/or disposal facilities, EPA has
prepared guidance which outlines the
proposed Part 268 regulatory
requirements with which waste handlers
will have to comply. The following
guidance provides references to
applicable Parts 264 and 265
requirements as well as proposed Part
268 requirements for implementation of
the various waste management options.
The waste management options
provided under Part 268 for the
treatment and disposal of restricted
wastes are dependent both upon the
type of waste and the concentrations of
hazardous constituents in the waste.
The following steps are offered as
guidance in determining the appropriate
waste management procedures to refer
to in Table 17 at the end of this unit.
Step 1. Determine whether the
hazardous waste is listed in Part 268
Subpart C. If not. the hazardous waste is
not a restricted waste and is not subject
to the'land disposal restrictions under
Part 268.
Step 2. If the waste is listed in Part 268
Subpart C, determine whether the waste
contains any hazardous constituents
with concentrations at or exceeding the
levels listed in Table CCWE under
§ 288.42. (See Procedure 1 below.) If
none of the applicable concentration
levels are met or exceeded, the
hazardous waste may be land disposed
without further restriction under Part
268. (See Procedure 6 below.)
Step 3. If die waste contains
hazardous constituents with the
concentration of any constituent at or
exceeding a level listed in Table CCWE.
the waste is subject to Part 268 land
disposal restrictions. If a treatment
technology is specified for the waste
.( under § 268.40(a). that identified
technology (see Procedure 2a below) or
an equivalent treatment method (see
Procedure 2b below) must be used to .
treat the waste. If a treatment
technology is not specified under
§ 268.40(a), any appropriate treatment
method may be used to reduce
hazardous, constituent concentration
levels to levels below any level listed in
Table CCWE of § 268.42. The exceptions
to Step 3 (applying the required
treatment standards of Part 288 Subpart
D) are as follows:
a. Case-by-case extension. An
application for an extension to an
effective date (see Procedure 3 below)
due to a shortage of treatment capacity
nationwide may be submitted to the
Administrator which if approved, would
allow continued land disposal of a
specific waste for up to two 1-year
periods.
b. Petition. Approval of a petition (see -
Procedure 4 below) would allow
continued land disposal of a specific
waste in a specific unit provided the
petitioner demonstrates such disposal is
protective of human health and the
environment.
c. Treatment in a surface
impoundment. Wastes may be treated
for up to 1 year in a surface
impoundment meeting specified design
and locationar requirements. (See
Procedure 5 below.)
Step 4. Restricted wastes which have
been treated in accordance with Step 3
may be land disposed without further
restriction under Part 268. (See
Procedure 6. below.)
TABLE 17—UNO DISPOSAL RESTRICTION PROCEDURES
BCBATSD Facilily Operating Undei
Procedure /.—Analysis to
Determine Constituent Con-
cerirations In Waste or
Waste Extract (40 CFR
268,6 and 268.40(b»).
za.—Use of an
Ideniiflea Technology to
Treat a Restricted Waste
(in CFR 268.40(81).
The generator must determine, through either test-
mg.or Knowledge of me waste, whether ha waste
meets; jt# treatment standards under 40 CFR
Paa-268 Subpart 0. If the hazardous constituents
n Mr wcste extract or waste do not exceed the
cone»rtration» listed .in Table, CCWE. the waste
S not subject to further restriction under 40 CFR
Part. 268. although the generator must designate
on the- manifest a land disposal facility which is
authorized to dispose of the wasie (40 CFR
262.20).
If the. hazardous constituents in the waste extract
or waste equal or exceed the treatment stand-
ards, the waste is subject to the land disposal
restrictions and the generator must pursue one or
more of the available options under 40 CFR Part
268 (case-by-case extension, petition, or treat-
ment).
The generator must send its waste to a facility that
has the ability to treat the restricted waste using
the identified technology found under 40 CFR
268.41.
The facility must either have documentattorr of tests
conducted by the generator or test the waste to
determine that such waste » in compliance with
applicable treatment standards. The waste must
be tested using the methods described in SW-
846 or equivalent methods approved by the Ad-
ministrator (40 CFR 268.6). The facility must
record the result of this testing in its operating
record (40 CFfl 265.73). '
If the hazardous constituents in the waste extract
or waste do not equal or exceed the 40 CFR
Part 268 Subpart D treatment standards, the
waste is not subject to further restriction under
40 CFR Part 268. although still a hazardous
waste, and may be land disposed at a RCHA
facility which has authority to manage the waste.
The. treatment facility must be able to apply the
identified technology designated for the restricted
waste complying with any standards specified for
that technology.
The treatment facility must provide certification of
proper treatment to the land disposal facility
receiving the treatment residue.
The faciftty must either have documentation of tests
conducted by the generator or test the waste to
determine such waste is in compliance with appli-
cable treatment standards. The waste must be
tested using the methods described in SW-846
or equivalent method approved by the Adminis-
trator (40 CFH 268.6). The facility must record
the result of this testing m its operating record
(40 CFR 264.73>.
if the hazardous constituents m the waste extract
or waste do not equal or exceed the 40 CFR
Part 268 Subpart D treatment standards, the
waste is not- subject to further restriction under
. 40 CFR Part- 288. although stiti a hazardous
waste, and may be land disposed at a RCRA
facility which has authority to manage the waste:
The treatment facility roust be able to apply the
identified technology designated for the restricted
waste complying with tne standards specified for
that technology.
The treatment facility must provide certification of
proper treatment to the land disposal faciP.v
receiving the treatment residue.
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Fodtnd Ragigtar / VoL 51. No. 9 / Tuesday, January 14. 1866 / Propomd Rates
procedure used in the Organic Toxichy
Characteristic to determine whether a
waste complies witb-Ahia standard.
C. Relationship To 40 CFR Paris 284 and
265 Standards
Compliance with the section 3004(m)
treatment standards does not relieve
owners and operators of their
responsibility to comply with other
applicable requirements such as the
requirement to install liners and
leachate removal systems, to conduct
ground water monitoring and corrective
action, and to comply with closure and
post-closure requirements and financial
responsibility requirements. In addition,
owners and operators are not relieved of
the responsibility to comply with
existing or future applicable location
standards.
IX. State Authority
A. Applicability of Rules in Authorizea
States
Under section 3006 of RCRA, EPA
may authorize qualified States to
administer and enforce the RCRA
program within the State. See 40 CFR
Part 271 for the standards and
requirements for authorization.
Following authorization, EPA retains
enforcement authority under sections
3008, 3013 and 7003 of RCRA, although
authorized States have primary
enforcement responsibility.
Prior to the Hazardous and Solid
Waste Amendments of 1384 remanding"
RCRA, a State with final authorization
administered its hazardous waste
program entirely in lieu of the Federal
program. The Federal requirements no
longer applied in the authorized State, '
and EPA could not issue permits for any
facilities in the State which the State
was authorized to permit. When new,
more stringent Federal requirements
were promulgated or enacted, the State
was obligated to enact equivalent
authority within specified timeframes.
New Federal requirements did not take
effect in an authorized State until the
State adopted the reqa&ementa as State
law.
In contrast, under newly enacted
section 3006(g) of RCRA, 42 U.S.C.
6926{g), new requirements and
prohibitions imposed by the HSWA take
effect in. authorized States at the same
time that they take effect in
nonauthorized States. EPA is directed to
carry out these requirements and
prohibitions in authorized States,
including the issuance of permits, until
the State is granted authorization to do
so. While States must still adopt
HSWA-related provisions as State law
to retain final authorization, the HSWA
applies in authorized States in the
interim.
Today's proposed rule would be
added to Table 1 in 5 271.1{j) which
identifies the Federal program
requirements that are promulgated
pursuant to HSWA. The Agency
believes that it is extremely important to
specify clearly which EPA regulations
implement HSWA since these
requirements are immediately effective
in authorized States. States may apply
for either interim or final authorization
for the HSWA provisions identified in
Table 1 as discussed in the following
unit of this preamble.
B. Effect on State Authorizations
Today's action proposes standards
that would be effective in all States
since the requirements are imposed
pursuant to section 3004 (d) through (k),
and (m) of HSWA, 42 U.S.C. 6924. Thus,
EPA will implement the standards in
nonauthorized States and in authorized
States until they revise their programs to
adopt these rules and the revision is
approved by EPA.
A State may apply to receive either
interim or final authorization under
section 3006(g)(2) or 3006(b),
respectively, on the basis of
requirements that are substantially
equivalent or equivalent to EPA's. The
procedures and schedule for State
program revisions under section 3006(b}
are described in 40 CFR 271.21 (see 49
FR 21678, May 22,1984). The same
procedures should be followed for
section 3006(g}(2).
Applying § 271.21(e)(2}, States that
have final authorization must revise
their programs within a year of
promulgation of EPA's regulations if
only regulatory changes are necessary,
or within 2 years of promulgation if
statutory changes are necessary. These
deadlines can be extended in
exceptional cases (40 CFR 271.21(e)(3)).
States with authorized RCRA
programs may have requirements
similar to those in today's proposed rule.
These State regulations have not been
assessed against the Federal regulations
being proposed today to determine
whether they meet the tests for
authorization. Thus, a~ State is not
authorized to cany out these
requirements in lieu of EPA until the
State program revision is approved. As a
result, the standards in today's proposed
rule will apply in all States, including
States with existing standards similar to
those in today's action. States with
existing standards may continue to
administer and enforce their standards •
as a matter of State law. In
implementing the Federal program, EPA
will work with States under cooperative
agreements to mhrimfag duplication of I
effort IB many cases, EPA will be able I
to defer to the States in their efforts to \
implement their programs, rather than I
take separate action* outer Federal I
authority. I
States that submit official application!
for final authorization less than 12 1
months after promulgation of EPA's I
regulations may receive approval I
without including standards equivalent I
to those promulgated. However, once I
authorized, a State must revise its I
program to include standards I
substantially equivalent or equivalent td]
EPA's within the time periods discussed!
above. 1
C. State Implementation I
There are four unique aspects of EPA I
actions under today's proposal which I
affect State implementation and the I
impact of State actions on regulated I
parties: I
1. Under section 288, Subpart C, EPA'J
imposition of nationwide disposal bans I
for all generators and disposers of I
certain types of hazardous wastes. I
2. Under § 268.41, EPA's granting of a I
national variance extension for all I
generators and disposers for up to 2 I
years, due to insufficient alternative I
national capacity. I
3. Under J 268.4, EPA's granting of
case-by-case extensions to the
nationwide bans for 1 year (renewable
for an additional year) for specific
applicants who lack adequate capacity.
4. Under § 268.5, EPA's granting of
petitions of specific duration to dispose
of certain hazardous waste in a
particular unit or units where it can be
demonstrated that there will be no
migration of hazardous constituents for
as long as the waste remains hazardous.
Regarding item 1, in order to retain
authorization, States must adopt any
national ban which EPA imposes under
RCRA. As provided in section 3009 of
RCRA, State requirements can be no
less stringent than those of the Federal
program.
Extending the imposition of a
nationwide ban (i.e., items b and 3
above} is the sole responsibility of the
Administrator of EPA and cannot be
delegated to the States. Because RCRA
section 3004(h)(3) refers to the
Administrator taking action specifically
after consulting with the affected States.
it is clear that the statute intends that
these actions be reserved for the
Administrator, not States. Further, the
actions are to be taken on the basis of
national concerns which only the
Administrator would be in the position
to be aware of and evaluate.
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Federal Register / Vol. 51. No: 9 / Tuesday, January 14, 1986 / Proposed Rules
employment, investment, productivity,
innovation, or international trade.
The Agencylias performed an
analysis of the proposed regulation to
assess the economic impact of
associated compliance costs. Based on
this analysis, EPA has determined that
the regulation of land disposal of
solvents and dioxins will not constitute
a major rule as defined by Executive
Order 12291. The total annualized cost
of restricting the land disposal of
solvent and dioxin wastes will not
exceed $100 million. However. EPA hasi
prepared Regulatory Impact Analyses in
support of this proposal, in recognition
of the scope of the regulatory framework
of which restrictions on land disposal of
solvent and dioxin wastes are only a
part, and of total costs of applying this
regulatory framework to all land
disposed wastes regulated under RCRA.
which will exceed $100 million (and.
therefore, would be a major rule).
Because of time contraints, the
regulatory impact statement does not
include a complete assessment of any
potential shift of wastes (and associated
risks) from land disposal to other media.
The Agency is taking steps to more fully
evaluate any potential shifts to the
ocean, or surface water as a result of
this decision rule to the extent that such
shifts would be allowed by law,
regulation, enforcement policy, or
market-place conditions. We solicit
comment and data on anticipated shifts
in waste treatment and disposal
because of this rule, including
comparative risk to human health and
the environment.
The following discussion summarizes
the methodology used in this analysis
and the findings on which the
conclusions above are based. More
detailed information is available in the
record and technical reports prepared in
support of this rulemaking.
The remainder of Unit XI.A describes
three analyses performed by EPA in
support of today's proposed rule. Unit
XI.A.I describes the analysis of the
economic impacts of restrictions on the
disposal of fast-track solvent and dioxin
wastes and on disposal ofcall RCRA
wastes generically. Unit XE"A.2 details
EPA's analysis of the environmental
benefits attributable to this proposed
rule. Finally, Unit XI.A.3 details EPA's
assessment of the costs and cost savings
resulting from petitions for variances
from proposed restrictions on land
disposal of all RCRA regulated wastes.
While these three analyses present
independent results and methodologies
specific to the objectives of each, they
share a consistent analytical framework.
The principal differences between the
analyses lie in the level of detail (i.e.,
site-specific versus national)
appropriate for conducting each. The
. specific assumptions,''methodologies and
results for each of these analyses are
further detailed in the Regulatory Impact
Analysis document and in the technical
documents available in the docket
supporting this proposed rule (Refs. 6, 7,
8 and 9).
1. Cost and Economic Impact
Methodology
EPA has assessed the costs and
potential economic impacts of this
proposal. The proposed regulation will
affect entities in a variety of four-digit
Standard Industrial Classifications
(SICs), including chemicals and allied
products, petroleum products, and
metals industries.
a. Baseline population and practices.
The baseline population is the total
number of hazardous waste generators
and treatment, storage, and disposal
facilities currently land disposing of
RCRA regulated wastes either directly
at the generation site or indirectly
through the purchase of commercial land
disposal services. This group's waste
management practices are evaluated to
identify correctly current costs of
managing wastes and to assess
incremental cost increases attributable
to today's proposal.
This analysis represents the baseline
population via a subset of respondents
to the Office of Solid Waste's
Regulatory Impact Analysis Mail
Survey.19 Waste quantities and
management costs for plants responding
to the RIA Mail Survey are scaled up to
represent the national population by
means of weighting factors developed
within the Survey. EPA estimates that
895 facilities comprise the total national
population currently land disposing of
RCRA regulated "wastes. Wastes are
generated for disposal off-site, EPA
estimates, by an additional 14,000 to
30,000 plants. Because the HSWA direct
the Agency to lower the exemption for
small quantity generators from 1,000 to
100 kilograms per month by March 31,
1986, SQGs generating between 100 and
1,000 kilograms of waste per month for
off-site disposal are also included in the
baseline population. The Agency
estimates that SQGs add 25,636 plants
19 EPA conducted the RIA Mail Survey of
hazardous waste generators'and TSDFs to
determine waste management practices in 1981. The
survey Included both generators of hazardous waste
and facilities treating, storing, or disposing of
wastes. Facilities that handled less than 1.000
kilograms of waste per month were not regulated in
1981 and thus are not included in, the data. For more
information, see the "National Survey of Hazardous
Waste Generators and Treatment. Storage and
Disposal Facilities Regulated under RCRA in 1981"
(Ref.116).
to the baseline. Plant- and waste-
specific data on this group are culled
ifrom OSW's Small Quantity Generator
Survey.
Baseline management practices for
these groups are characterized by
adjusting waste management practices
as of the 1981 Mail Survey to reflect
compliance with the provisions of 40
CFR Part 264 and any other regulatory
requirements which predate this
proposal.-In making this adjustment, the
Agency assumes plants elect least-cost
methods of compliance. This adjustment •
defines not only baseline management
practices and costs associated with
them, but also the number of waste
streams in the baseline. For example, for
60 facilities, the costs of land disposing
certain wastes are driven so high by
regulations predating this proposal that
other management modes are less
• expensive. EPA assumes that these
facilities no longer land dispose of these
wastes and that these wastes are no
longer part of the base line population of
waste streams which may be affected
by any restrictions on land disposal.
For much of the population examined
in this analysis, no aggregate models
have been developed. Individual
observations in the RIA Mail Survey
have instead been treated as models,
and weighted to represent the national
population of wastes and management
practices. In the analysis of SQGs,
survey data provide a range of
observations within each SIC from
which a SIC-average plant can be
modelled. For some dioxin wastes,
individual plants are identified because
they represent the majority generator of
a particular waste type. For other-dioxin
wastes, typical plant characteristics are
used to assess economic impacts.
b. Development of costs. The analysis
detailed in this'unit is based on cost
estimates for surveyed plants
representing the baseline population.
Plants face several possible options if
they may no longer land dispose of their
wastes. EPA applies the same rationale
in predicting plant choice among these
options as it does in establishing the
baseline population: firms are assumed
to elect the least costly method of
complying with the requirements of this
proposal.
EPA developed baseline waste
management cost using engineering
costs models. Costs for disposal in
surface impoundments assume-
compliance with section 3005(j) of
RCRA, which requires surface
impoundments to retrofit fully with
double liners with leachate collection
systems between liners subject to
certain exemptions.. This assumption
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Federal Register / VoL 51,. No. 9 / Tuesday, January 14> 1985 / Proposed Rules
TABLE 17—LAND DISPOSAL RESTRICTION PRICEOURES—Continued
Generator
HCRA TSD Facility Operating Under Interim Status BCRA TSD Facility Operating Under a Permit
Ptocedm Stj.—Use of art The generator must send its waste to a facility that
Equivalent Treatment has the ability to treat the restricted waste using
Method to Treat a Restrict- an Equivalent Treatment Method approved by the
ed Waste (40 CFR 288,40 Administrator.
(a)).
Proctdurt 3.—Case-by-Cas*
Extensions ol Effectiva
Dates to Allow Continued
Land Disposal ol • Re-
stricted Waste (40 CFR
268.4).
Procodun 4.—Petition* to
Allow Land Disposal at »
Restricted Wast* (40 CFR
268.5).
Proctdun 5.—Treatment of
Restricted W**M* in Cer-
tain Surface Impoundment*
(40 CFR 288,1 (c)).
Generators seeking a case-by-case extension must
apply to the Administrator. The extension does
not become effective until a notice of approval is
published In the FEDERAL REGISTER or the
generator receive* an approval notice from the
Administrator. The generator must forward a copy
of the approval notice to the land disposal facility
receiving its waste before shipping the wast* to
the facility. The generator must retain the notice
of approval in his records (40 CFR 262.40).
The generator should hava evidence that the facili-
ty ha* an approved petition to land dapose of a
specific restricted waste before shipping that
waste to the facility for disposal. The generator,
itself, may also Hi* a petition or be a party to a
petition with a treatment, storage, and Disposal
facility.
The generator must send its wastes to a treatment
(•dirty that ha* an impoundment that meets the
minimum technological requirements, i.e., ha*
been constructed with a double Knar (with limited
exception*) and to in compliance with ground
water monitoring requirements.
Pnxtdtn &—Land Diepoaal The generator mutt determine, through either tast-
of Wtrtas that Meet 40 Ing or knowledge of hi* waste, that hi* MM*
CFR Part 288. Subpart O meets th* 4O CFR P»rt 266 Subpart D standard*
Slanoard*. and h. Bieratae. no longer a restricted wast*.
before shippInQ th* wMfct (wltn accompanying
manlfacf) tor ant depoul to a f*ci*ty w*f>
Interim SMua or a RCRA permit
The treatment residue, after treatment by the re- The treatment residue, after treatment by the i
quired tecrtnotogy(ias), must be managed as a quired tecnnology(ies), must be managed as i
hazardous waste ' but may be land disposed: hazardous waste' but may be land
The treatment facility must petition the Admmistra- The treatment facility must petition the <
tor for approval of an Equivalent Treatment tor for approval of an Equivalent Tre
Method in accordance with 40 CFR 268.41(b). Method in accordance with 40 CFR 268.41(bf
The treatment facility must provide certification of
proper treatment to the land disposal facility
receiving the treatment residue.
The treatment residue, after treatment by the re-
quired technology(ies), must be managed as a
hazardous waste ' but may be land disposed.
Land disposal facBHe* seeking a case-by-case. ex-
tension must apply to the Administrator. The
extension does not become effective untn a
notice of approval is published in the FEDERAL
REGISTER or the disposal faculty receive* an
approval notice from the Administrator. The facili-
ty must have a copy of the approval notice in Its
operating record and must keep an accounting of
the waste disposed under the extension (40 CFR
265.73(b)(8)). This approval notice may be for-
warded by th* generator or obtained by the
disposal facWty directly.
The facility must submit * petition to the Director >
and receive c notice of approval before it can
land dbpos* of a restricted waste. A copy of the
approval notice must be kept on We in the
operating record.
The'facility must have interim status (or an so--
proved change under interim status) to manage
the restricted wast* and to operate the land
disposal process.
The facility must compr/with all conditions of the
approval.
Th* facility must have Interim Status (or on ap-
proved change under Interim Status) to manage
th* restricted waste and operate th* treatment
process.
The impoundment roust meet the minimum technol-
ogy requirements in accordance with 40 CFR
265.221 (a) through (e) and be in compliance
with 40 CFR Part 26S Subpart F.
The facility must analyze the contents of the im-
poundments annually in accordance with 40 CFR
26e.1(e)<2>.
nVejUMmdnMnt rukiuo tlmt do0s not rrxwt ttw
standards found under 40 CFR 268.42 or 268.43
must be removed and managed a* a restricted
wast*, but cannot b* further treated in an im-
poundment
Residue that maet* the standard* found under 40
CFR 268 Subpart D can remain in th* impound-
ment or can b* otharwi** land disposed. Th*
residue must b* managed as a hazardous waste.
The facility must have Interim Status (or an ap-
proved change under Interim Status) to manage
the'
Th* faculty must have record* and results of waste
anriyde peitamed (40 CFR 266.13 and 268.6),
documenting In th* operating record that th*
wast* meet* 40 CFR Part 268 Subpart D stand-
ardaand may b* Ian* dfeposad without further
The treatment facility must provide certification i
proper treatment to the land disposal (acini
receiving the treatment residue.
The treatment residue, after treatment by the i
quired technotogy(ies), must be managed as
hazardous waste' but may be land dra
Land disposal faculties seeking a case-by-cas* exl
tension must apply to the Administrator. Th
extension does not become effective until i
of approval is published In the FEDERAL REG
TEH or the disposal facility receives an i
notice from the Administrator. The facility
hav* a copy of the approval notice in its <
ing record and must keep, an accounting of I
waste disposed under the extension (40 CFR_
264.73(b)(10)). The approval notice may be for|
warded by th* generator or obtained by
disposal fadtty directly.
The facility must submit a petition to the Director "|
and receive a notice of approval before it <
land dispose of a restricted waste. A copy of t
approval notice must be kept on file in
operating record.
The facility must have a permit which includes I
,must modHy its permit to include) the i
wast* code* to be managed arid the land <
a) process.
The facility must (through permit conditions) t
with aH conditions of the approval.
Th* facility must have a permit which includes (a
must modify its permit to Include) the i
waste, to be managed and the treatment i
to be operated.
The impoundment must meet the minimum technc4*l
ogy requirements in accordance with 40 CFRI
264.221 (a) through (e) and must be in eompH-l
ance with 40 CFR Part 264 Subpart F.
The facility must analyze the contents of the im-l
poundments annually in accordance with 40 CFR I
268.1 Unto** th* rcsldu* haa-been delated (40 CFR 260.22) or the residue fa th* result of treating * wast* that I* hazardous solely became It exhibits one or more hazardous wast* I
charactertillci (40 CFR Part an Sabpaa C) and the residue no-longer eahibits tie ehaiactoiHtlcta): . I
'Orector I* a* defined under 40 CFR 270.2. —~—w
XI. Regulatory Requirements
A. Executive Order 12291
Executive Order 12291 requires that
the regulatory impact of potential
Agency actions be evaluated during the
development of regulations. Such an
assessment consists of a description of
the potential benefits and the potential
costs of the rale, including any
beneficial and any adverse effects
which cannot be quantified in monetary
terms.
In addition. Executive Order 12291
requires that regulatory agencies
prepare a Regulatory Impact Analysis in
connection with major rules. Major rules
are defined as those likely to result in:
(1) An annual effect on the economy of
$100 million or more; (2) a major
increase in costs or prices for consumers
or individual industries; or (3) significant
adverse effects on competition.
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1742
Federal Regster / Vol. 51r N6; 9-./ Tctewfay, lanuary 14, 1988 / Propcwed Rales
regulation. EPA has treated this •
rulemaking as major, although on the
basis of costs incurred by plants
complying with restrictions on solvent
and dioxin wastes it cannot be
considered major. Further, in an attempt
to assess the national economic impacts
of the proposal, the Agency has
evaluated the total costs of the
regulation.
Total annualized costs of restricting
land disposal of all RCRA-regulated
wastes are estimated at $1.3 billion.
These costs do not exclude taxes, which
are merely transfers from one sector of
the economy to another, and are stated
in 1984 dollars. These costs may slightly
understate total surface impoundment
compliance costs to the extent that
usable capacity in disposal
impoundments must be wasted in
switching to alternative disposal modes.
The Agency will assess this possibility
and revise cost estimates where
appropriate. These costs are derived by
weighting plant-specific compliance
costs by the part of the total national
population they represent, and then
summing these weighted costs across all
affected SICs. These weighting factors,
however, cannot be used to scale up
economic impacts to represent those
likely to occur at the national level. The
weighting factors are specific to
individual waste streams, and were
never intended to reflect firm economic
context. For the purposes of the
economic analysis, SICs must be
unambiguously related to individual
plants. Tims, all economic impacts are
expressed in unweighted form.
Four SIC sectors account for
approximately 70 percent of all land
disposal restriction compliance costs.
SIC 28, chemicals and alKed products,
alone accounts for 28 percent. Three
other SICs als& contribute significant
amounts, although much less: SIC 29.
petroleum refining, accounts for 14
percent SIC 33, primary metals,
accounts for 23 percent and SIC 34,
fabricated metal product^ accounts for
6 percent.
Economic impacts have been assessed
for both non-commerciai and
commercial facilities. Non-commercial
facilities are those watch generate and
manage their own wastes, as distinct
from facilities which accept fees hi
exchange for management and disposal
of wastes generated by others. Of 413
unweighted non-commercial facilities
nationally, 175 experience financial
effects in excess of the 5 percent test on
either compliance cost to cost of
production or compliance cost to cash
from operations or both. For some
plants, such as those in the steel
industry (SIC'33), compliance costs
represent an added burden at a time
, when the industry as a whole is •
experiencing financial reversals. For
other plants, costs simply represent a
large increment over costs of
unrestricted land disposal.
Of the SO most significantly affected
facilities, 80 percent belong to four
industry groups. In SIC 28, chemicals
and allied products, 23 facilities may
experience severe impacts. In SIC 33,
primary metals processing, 11 facilities
are likely to be similarly affected. In SIC
29. petroleum refining, three facilities
may incur economic impacts, and
finally, in SIC 34, fabricated metal
products, three facilities may be
affected.
Commercial facilities are those which
manage the wastes generated by ofter
firms tar a fee. For these facilities.
economic impacts are impossible to
assess directly due to the lack of any
appropriate SIC from which to draw
financial data. EPA's analysis therefore
assumes that commercial facilities are
able to pass the costs of regulatory
compliance on to the purchasers of their
services in the form of higher prices. The
financial impact of this regulation is
thus assumed to fall on consumers of
' commercial hazardous waste
management services.
As a result of the restriction on land
disposal of afl RCRA-regulated wastes
53 commercial facilities incnr
incremental costs. Based on RIA Mail
Survey data, the five SICs which send
the majority of each facility's waste
have been identified. Actual plants
generating these wastes cannot be
identified rising RIA Mail Survey data.
Therefore, EPA's analysis assumes that
aH wastes reported from a given SIC
come from a single generator within that
SIC. Ratios of the compliance costs for
treating the total quantity of waste from
a SIC to SIC-average values for cash
from operations and to costs of
production are taken for each industry
sector which constitutes a primary
source of waste for each of these 53
facilities. This procedure is Kcely to
overstate significantly economic impacts •
among generating plants.
Significant economic impacts based
on cosis imposed by restrictions on land
disposal are evinced by 110 SIC sectors.
This represents nearly 80 percent of aH
waste-generating sectors which may
have to pay increased waste
management prices. Most significantly
affected plants belong to four industry
groups. In SIC 28. chemicals and allied
products, 30 plants may experience
severe impacts.-In SIC 33, primary
metals processing, 23 plants are also
likely to be affected adversely. In SIC
29, petroteum refining, 16 plants may
incur economic impacts, and in SIC 34.
fabricated metals products, 15 plants-
may incur economic impacts.
More indepth financial analysts was
then performed to verify the results of
this, impact analysis based on firm-
specific financial data. For
approximately 70 percent of the
population of large quantity generators
disposing on-site and commercial
facilities (unweighted: 310 out of 466).
these data are available. Ratio tests
performed for these firms include
compliance costs to cash-flow,
compliance costs to net income, and
compliance costs to total assets.
Compliance costs used in this analysis
are after-tax values, to preserve
comparability with the after-tax
financial data used.
In the three ratio tests, 27 plants
exceed threshold values and are thus
considered likely to be affected severely
by costs imposed by this regulation.
These plants represent 9 percent of the
310 for. which financial data are
available. This result differs
significantly from results obtained using
SIC-average financial data, and suggests
that the general screening analysis may
overstate economic impacts;
Total annualized national costs for the
25,636 small quantity generators of
RCRA regulated wastes are $21.7
million. Based oa engineering estimates
. of prices for off-site waste management
services, costs for SQGs generating the
maximum of 1,000 kg/mo of nothing but
hazardous wastes would incur not more
than $5,070 annually in incremental
compliance costs. Economic ratios for
typical plants in each 4-dagit SIC sector
represented in the SQG survey were
examined, and in no case did the ratios
exceed OJ3 percent. Thus, land disposal
restrictions on RCRA-regulated wastes
are not expected to cause economic
impacts among generators of small
quantities of wastes.
Changes m costs of waste treatment
and disposal oh a pergalion basis
provide an additional measure of
economic impact. Baseline management
costs for waste land disposed by
noncommercial facilities average $0.021,
compliance costs average $0.46, and
incremental costs average $0.25. Thus,
baseline waste management costs have
been increased by 12O percent. For
wastes currently disposed of at
commercial facilities, baseline costs
average $0.89, compliance costs average
$1.99, and incremental costs average
$1.30. This represents a 190 percent
increase in baseline management costs.
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Federad Register / Vol. 51, No. 9 / -Tuesday. January 14, 1986 / Proposed Rules
could lead tq an overestimate of
baseline disposal costs, and, thus, to an
underestimate of incremental costs for
surface impoundments exempted from
these requirements. Existing
requirements under RCRA are also
considered in developing costs for
disposal in landfills and waste piles.
Wastes amenable to similar types of
treatment are grouped to identify
economies of scale available through co-
disposal and treatment
Compliance waste management costs
are derived by predicting the minimum-
cost method of compliance with land
disposal restrictions for each plant and
calculating the increment between that
and baseline disposal costs. As in the
analysis of baseline costs, economies of
scale in waste management are
considered.
Shipping costs for wastes sent off-site
for management are also considered. In
the development of baseline waste
management costs, the transportation
distance assumed for off-site waste
Ireatment and/or disposal is 100 miles.
Most plants currently sending wastes
off-site do so for disposal. Although the
likely effect of restrictions will be to
require treatment before and in addition
to disposals, the Agency has assumed.
that off-site disposers ship no additional
incremental distance as a result of the
proposed regulations. In essence, EPA
assumes that commercial facilities
which currently dispose of the major
portion of the wastes they receive can
also treat this portion prior to disposal if
necessary. EPA examined the sensitivity
of results to this assumption and this
analysis revealed that varying the
assumption in travel distances, even by .
as much as a factor of eight, has a minor
effect on results. This is because many
plants which send wastes off-site send
small amounts; thus, economies of scale
reflected in per unit prices of waste
disposal at large commercial facilities
outweigh even a major increase in,
shipping costs. Although EPA found that
varying transportation, coats has a minor
impact on the decision to ship off-site, in
the Agency's analysia;of petition costs,
which is discussed hi more detail in Unit
XI.A.3 of this preamble, transportation
costs were found to have a greater
impact on a firm's decison to petition.
Costs of compliance include costs for
pretreatment, of handling residuals and
the value of byproducts of the various
treatment technologies. For wastes to be
distilled, for example, pretreatment may,
be necessary. Becasue of this,
pretreatment costs have been added to
those of distillation. In the case of
incinerated wastes, costs of disposal of
residual ash are added. And in the case
of distilled solvents, when treatment
generates saleable recovered products,
the value of these products has been
deducted from total costs of waste
treatment.
EPA developed firm-specific
compliance costs in two components
which are weighted and then summed to
estimate total national costs of the
proposal. The first component of the
total compliance cost is incurred
annually for operation and maintenance
(O&M) of alternative modes of waste
treatment and disposal. The second
component of the compliance cost is a
capital cost, which is an initial outlay
incurred for construction and
depreciable assets. Capital costs are
restated as annual values by adjusting
them into equivalent yearly payments
using a capital recovery factor
calculated based on a real cost of
capital of 7 percent. These annualized
capital costs are then added to yearly
O&M costs to derive an annual
equivalent cost by which annual firm
cash-flow may be reduced by the
regulation.
c. Economic impact analysis
methodology. Economic impacts are
assessed in several steps. First, a
general screening analysis compares
plant-specific incremental costs to SIC-
average financial information
disaggregated by number of employees
per plant. Two ratios are used to
identify plants likely to experience
adverse economic impacts. From the
1982 Census, values for cost of
production and cash from operations are
derived by a four-digit SIC for each of
several employment size categories. A
ratio of individual plant compliance
costs to each of these values is taken,
and a change of more than 5 percent is
considered an economic impact. This
analysis considers only pre-tax costs,
because Census data are stated in
before-tax terms.
Once SIC sectors experiencing
adverse economic impacts are identified
using the two screening ratios, more
indepth financial analysis is performed
to verify the results and focus more
closely on affected firms. For the subset
of firms which appear to incur sufficient
economic impact.to warrant more.
detailed analysis and for which such
data are available, .annualized plant-'
specific compliance costs are deducted
from annual cash-flow values. Firm-
specific financial data used in this
analysis are derived from economic
reporting services such as Robert Morris
Associates or Dun & Bradstreet.
This cash-flow analysis-can be
misleading, however, since for some
firms,, cash-flow values reported for 1984
are negative. Clearly, this does not I
represent typical financial performancel
for these firms. Businesses may weathel
a year of poor cash-flow values, I
however, if they have a strong asset I
base and an expectation that financial I
conditions will improve. For these firms!
therefore, EPA has conducted further I
analysis using alternative measures of I
economic size such as net income, I
assets and liabilities. This improves thel
assessment of the significance of the I
negative cash-flow values and of these I
firms' probable response to compliance I
costs. I
d. Small business impact analysis I
methodology. In the small business I
impact analysis supporting this I
proposed rule, EPA has defined small I
business as firms employing fewer than I
50 people. EPA has elected not to adopt I
the Small Business Administration's I
definition of small business, which is I
fewer than 500 employees for most SICsl
because it would include the majority on
plants hi the regulated community. I
Using a threshold value which includes I
a majority of the total population I
obscures any differential impacts on I
smaller firms. The Agency considers a I
threshold value of fewer than 50 I
employees to be a more sensitive index I
of impacts on small businesses. I
Economic impacts on small I
businesses are examined in two phases. I
Fust, the screening ratios, compliance I
cost to cash from operations and I
compliance cost to costs of production, I
are used across all sizes of firms in the I
analysis. The total small business I
population is then examined discretely I
to evaluate the percent of this total I
population exceeding the 5 percent I
threshold on either ratio. Then, EPA
compares results of these ratios for the
large firms in the total SIC to results for
the subset considered small business. A
substantial difference in the results of
these ratios implies that average
impacts for large firms differ markedly
from average impacts for small firms
within that population. These analyses
allow EPA to evaluate whether or not a
substantial number of small firms incur
significant economic impact in
complying with the proposal.
2. Costs and Economic Impacts
. a. Total national costs and economic
impacts for all RCRA-regulated wastes.
In addition to proposing land disposal
restrictions applicable to solvent and
dioxin wastes, today's proposal details
a framework which the Agency will
apply to all RCRA-regulated wastes
according to the congressionally
mandated schedule. Because of the
ultimately national, impact of this
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1744
Federal Renter / Voi. 51. No; » / Tuesday. January 14, 1986 / Proposed Rules
were excluded from the population of
candidates most likely to petition.
A sub-set of petition candidates for
whom a variance from the ban is a
feasible option was created. EPA*
predicted feasibility of applying for a
variance by using the Liner Location
Risk and Cost Analysis Model (LLM) to
evaluate each candidate's ability to
meet the performance standard that
there would be negligible risk (denned
as no greater risk than one in a million
(1CT6) that a Maximum Exposed
Individual would be affected), at
designated compliance points. Because
of the waste-specific nature of the ban
decision, and the requirements for
demonstrating for a variance, the
analysis was on a facility/specific-
waste stream basis.
EPA evaluated the feasibility of a
variance from land disposal bans at
three different compliance points. The
broader standard defines the
compliance point as the nearest receptor
point, i.e., the closest ground water well
A more restrictive standard's
compliance point is at the facility
boundary. An even more stringent
compliance point is at the waste
nianagement unit boundary. Those
candidates with negligible risk (assumed
to be <1
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Federal Register / Vol. 51^ No. 9 / Tuesday, January 14. 1986 / Proposed Rules
For wastes currently stored in surface
impoundments at noncommercial
facilities, baseline waste management
costs average $0.0021 per gallon,
compliance costs average $0.0096, and
incremental costs average $0.0075. Thus,
typical management costs are increased
by approximately 360 percent. For
commercial facilities, baseline costs
average $0.0056, compliance costs
average $0.0189, and incremental costs
average $0.0133. Thus, typical
management costs are increased by
about 240 percent.
For wastes currently treated in
surface impoundments at •
noncommercial facilities, baseline
management costs average $0.0017 per
gallon, compliance costs average .
$0.0051. and incremental costs average
$0.0034. This-represents a 200 percent
increase in management costs. For
commercial facilities, baseline
management costs average $0.053,
compliance costs average $0.0123 per
gallon, and incremental costs average
$0.0070 per gallon. Thus, typical
management costs are increased by
approximately 130 percent.
b. Total costs and economic impacts
for solvent wastes. Total annualized
compliance costs for plants currently
generating and disposing of solvent
wastes are $70.5 million. Although SQGs
constitute 99 percent of this total
population, they account for only 13
percent of the total costs.
Economic impacts have again been
disaggregated into impacts on non-
commercial and commercial facilities.
Among non-commercial plants, only
three incur compliance costs greater
than 5 percent of costs of production.
The most severely affected facility is in
SIC 2999, which may incur a 9 percent
increase in costs of production and a 52
percent reduction in cash from
operations. Five other facilities incur
reduction in cash from operations
greater than 5 percent. These are in SIG
2865, in which two facilities may
experience reductions in gross margin of
52 percent and 6 percent; SIC 2900, in
which a facility may experience a 13
percent decline in cash from operations;
SIC 2861, in which one firm's cash from
operations may decline by 11 percent;
and SIC 2819, in which a facility's cash
from operations may drop by 26 percent.
Among commercial facilities—those
which manage the wastes of other firms
for a fee—direct impacts were
impossible to assess due to the lack of
financial data, even on an aggregate
basis. Therefore, EPA's analysis has
assumed that commercial facilities will
be able to pass the increased costs of
regulatory compliance on to their
customers in the form of higher prices.
The burden of this regulation is thus
assumed to fall on consumers of
commercial hazardous waste
management services. x
Fifteen commercial facilities incur
incremental costs as a result of this
regulation. Based on RIA Mail Survey
data, the five industrial sectors which
send the majority of each facility's
waste have been identified. Ratios of the
compliance costs to cash from
operations and to costs of production
are taken for each SIC which constitutes
a primary sector of waste origin for one
of these 15 facilities.
This analysis identifies 23 sectors as
experiencing significant impacts. This
represents over 30 percent of all'solvent
waste generating sectors. Of these, five
include two or more severely affected
firms. All plants identified as having
significant impacts exceed the 5 percent
criterion for the cash from operations
ratio, and 10 plants exceed 5 percent in
the cost of production ratio as well.
Among the most adversely affecte'd
plants are those in SIC 5500, which incur
a 7.7 percent increase in costs of
production and a 107 percent decrease
in cash from operations. Plants in the
primary metals processing industries
also experience significant impacts: two
in SIC 3300 and one in SIC 3341. Other
affected sectors include SIC 34,
fabricated metal products, and SIC 28,
the chemical industry.
Total annualized costs for the 13,468
small quantity generators of solvent
wastes are $9.5 million. Based on the
estimated cost for off-site incineration,
maximum incremental compliance costs
for any individual SQG will not exceed
$3,275 annually. Economic ratios were
examined for typical SQGs in each SIC
sector identified in EPA surveys as
generating solvent wastes. In no
instance did economic ratios exceed 0.6
percent. As a result the Agency does
not anticipate that this regulation will
impose significant economic impacts on
typical small quantity generators in any
SIC sector.
c. Total costs and economic impacts
for dioxin wastes. Total annualized
compliance costs for all sources of
dioxin wastes are $3.8 million. Costs for
managing that portion of the estimated
1.1 billion pounds of existing dioxin-
contaminated soil to which this
regulation will apply are $7 million.
Preliminary testing of dioxin-
contaminated soils suggests that only 5
percent of the total quantity will, require
incineration, and the costs reflect this
finding. Of these soils, EPA estimates 95
percent can-continue to be lahdfilled,
because they show no teachable dioxin.
Economic impacts appear most
significant for plants in SIC 2869 as a
result of the restriction on dioxin
wastes. This sector manufactures
industrial organic chemicals, with majoij
products such as solvents, noncyclic
organic, and polyhydric alcohols. Other |
affected sectors include 2879, in which
one plant may close, and-5161, which
may experience several plant closures:
SIC 2879 includes plants manufacturing I
pesticides and agricultural chemicals foi
immediate household and farm use. S1C|
5161 comprises distributors of acids,
heavy chemicals, and industrial salts.
3. Cost Analysis of Petitions
a. Introduction. The Agency
conducted a cost analysis to estimate
the unit costs for a petition for a
variance from the land disposal
restriction; the national costs are based
on the expected number of petitions to
be submitted, and subsequently granted;)
and the savings that would accrue to
petitioners receiving a variance.
This unit of the preamble is a
summary of the cost analysis,
documented in "Cost Analysis of
Variances to Land Disposal Bans" (Ref.
7).
b. Methodology. EPA's analysis
evaluated three issues: the contents and I
unit cost of a petition, considering
various options for a petition
demonstration; the number of petitions
that are likely to be submitted; and the
savings available to generators that
choose to petition and are granted a
variance.
To address these issues EPA used a
simulation model that describes the
options and outcomes for the regulated
populations and estimated and
compared the expected cost of the
options. Using this framework, EPA
simulated the response to a ban
decision; whether to accept the ban and
comply with treatment standards or to
submit a petition. To complete the
analysis the Agency conducted the
following steps:
EPA first estimated .the population of
regulated facilities that may be affected
by petitions for variances from land
disposal bans. Existing data on
generators that land dispose their
wastes were obtained from the
"National Survey of Hazardous Waste
Generators and Treatment, Storage, and
Disposal Facilities Regulated Under
RCRA in 1981" (Ref. 116).
For this analysis, the assumption was
made that all wastes are banned from
land disposal. It was also assumed that
commercial facilities would encourage
treatment, and thus generators that
shipped their waste to these commercial
facilities would not opt for applying for
a variance. Therefore these generators
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Federal Register / Vat. 51. No. 9 / Tuesday. January 14. 1986 7 Proposed Rules
costs for both treatment and disposal at
candidate facilities. In general, that
would result in fewer expected petitions.
At the same time, since a petition will
contain a great deal of information that
is site-specific independent of the waste,
the additional cost of preparing a
second petition for a second waste
would be much less than for the first
This would result in more petitions
being submitted.
EPA also assumed for costing
purposes that a facility owner/operator
could submit one petition for a waste
stream that contained multiple wastes,
rather than a separate petition for each
waste. If instead EPA had considered S
each waste separately, the number of
petitions, and the associated costs
would have increased substantially.
Finally, the functions that EPA used to
estimate disposal costs were based on
the volume of only one waste stream.
Therefore, incremental costs of savings
will be greater if the waste was one of
several placed hi the unit. This
assumption resulted in an overestimate
of both costs and savings at some
disposal units. The savings were so
large in some cases that they
overwhelmed the incremental cost of
treatment.
d. Results. EPA's approach gives an
estimated fraction of petition candidates
who find it less expensive to petition for
a variance from the land disposal ban
than to comply-with the treatment
standards imposed by the ban. EPA
estimated the number of petitions, the
petition costs, and the savings accruing
to petitioners under several different
scenarios. The scenarios were defined
by different assumptions about the cost
to prepare a petition, the performance
standard for petitions, and the
probability of receiving a petition once it
is submitted. The following Table
summarizes the results for each
scenario:
TABLE 18.—RESULTS SUMMARY FACILITY
BOUNDARY COMPLIANCE POINT
[Dollars in mifltoral
TABLE 18.—RESULTS SUMMARY FACILITY
BOUNDARY COMPLICE POINT—Continued
,-;~;-'.v-i;-—* ^ • •> ,' • . "'•*«&; '• ,,
- <•••••- tOdlars in millions] "
Probability
High probability:
Population: Number of pe-
titions
Total annualized costs
Total annualized saving
(Treatment-petition cost)..
Medium probability:
Population: Number of pe-
titions
Total annuaSzed costs
Total annualized saving
(Treatment-petition cost)..
Low probability:
Population: Number of pe-
titions
Annualized petition cost
Low
$11.000
190
$2.1
$59
133
$1.5
$59
76
Medium
$44,000
114
$5.0
$55
78
$3.3
S54
38
High
$217.000
38
$8.2
$42
38
$8.2
$42
t {
Probability .
Total annualized costs
Total annualized saving
(Treatment-petition cost).
NEAREST WELL
COMPLIANCE POINT.
High probability:
Population: Number of pe-
titions.
Total annualized costs
Total annualized saving
(Treatment-petition cost)..
Medium probability.
Population: Number ol pe-
titions
Total annualized costs
Total annualized saving
(Treatment-petition cost)..
tow Probability:
Population: Number of pe-
titions
Tola! annualized coats
Total annualized saving
(Treatment-petition cost)..
Annualized petition- cost
Low
$11.000
$0.8
$56
36T
' $4.0-
$159
285
$3.1
$159
171
$1,9
$154
Medium
$44,000
$1.7
$48
247
$10.9
$150
171
$7.5
$146
57
sas
5132
High
$217,000
' fc.4
$21
95-
$20.6
$122"
57
. $144-
' $120
38
$8.2
$93'
i. Number of facilities where a
variance is a feasible option. The
number of facilities where a variance
was a feasible option depended on the
compliance point. At the disposal unit
as the compliance point, the variance
was not a feasible option. The expected
risks from exposure to those
concentrations of leachate at the
disposal unit edge were significant
(>10"6) for all waste characterized.
Therefore, no petitions are expected for
demonstrating.safe levels of exposure at
this compliance point.
.Table 18 shows how the other two
compliance points (the facility boundary
• and the nearest water well) affected the
results. Different compliance points
made a significant difference in the
number of petitions. The more restrictive
compliance point at the facility
boundary cut the number of petitions by
approximately one-half in every
scenario.
At the waste facility boundary
compliance point the variance was a
feasible option since 494 facilities
passed the risk screen (a risk of <10~8).
When the compliance point was '
designated as the nearest drinking water
well, 722 facilities passed the risk
screen, thereby making the variance a
feasible option.
ii. Costs to prepare a petition. The
estimated cost to prepare and submit a
petition ranged from a present value of.
$170.000 to $3,220,000 with a medium
estimate of $652,000. The annualized
costs, assuming the petitioner could -
spread his costs over 20 years, ranged
from $11,000 to $217.000 with a medium
estimate of $44,000. The costs were
assumed constant for all volumes and
types of wastes. Changing petition costs
., from the low to the medium estimate
reduced the number of petitions by 30 to
60 percent. Increasing petition costs.*
from the medium to the high estimate
further reduced the number of petitions
by 50 to 70 percent.
The total annualized petition costs,'
ranged from $800,000 per year to $20,6
million per year, depending on the
petition cost and the compliance point.
iii. Savings to the petitioners. The
total annual savings ranged from $21
million to $159 million depending on unit
petition costs, the probability of being
granted a petition, and, most
importantly, the compliance-point.
Since petition costs do not vary with
volume (and treatment costs do), there
is a tendency for high volume generators
to be more prevalent among the
population of petitioners. These
candidates, with a very high cost of
compliance with treatment standards,
dominated the estimated cost savings.
At the facility boundary the total
savings ranged from $21 million to.$59
million per. year. At the nearest well
compliance point the savings ranged
from $93 million to $59 million per.year.
4. Review of Supporting Documents and
Request for Public Comments
a. Review of supporting documents.
The primary source of information on
current land disposal practices and
industries affected by the proposed
regulation is EPA's National Sarvey of
Hazardous Waste Generators and
Treatment, Storage and Disposal
Facilities (Ref. 116). Waste stream
characterization data and engineering
costs of waste management are based
on the Mail Survey, on reports by the
Mitre Corporation, "The RCRA Risk-
Cost Analysis Model," and an internal
EPA memo titled "Final Reports on the
Evaluation and Validation of
Acceptance Daily Intake (ADIs) in
Support of RCRA Ban Decisions" (Refs.
116. 78.118, and 39). The survey of small
quantity generators has been the major
source of data on this group (Ref. 115).
EPA's Office of Research and
Development provided the report
fundamental to the dioxins analysis.
"Analysis of Technical Information to
support RCRA Rules for Dioxins-
Containmg Waste Streams," July 1985
(Ref. 67).
For financial and value of shipment
information for the general screening
analysis, 1982 Census data were used. A
primary source of firm-specific financial
information is Dun & Bradstreet's
"Business Information Reports."
Secondary sources include data from
-------
_"" ••••> ,. -antes- -
Federal Register / VoL 51, No. 9 / Tuesday, Jaauary 14. 1986 / Proposed Rales
On-site treatment costs were
estimated for the remaining candidates.'
waste using the technology and cost
information based on model plant data
contained in the WET Model (Ref. 118).
Generally, EPA assumed only a single
treatment step and that the volume of
waste currently disposed of was equal
to the design capacity for the treatment
facilities.
EPA estimated annualized costs for
constructing and operating each
technically feasible treatment plant for
each candidate facility-waste
combination. EPA then selected the
least cost treatment for each candidate's
waste type and volume.
Disposal costs were estimated based
on the residual waste volumes
calculated by the WET Model. The
Facility Design Cost Model of the Liner
Location Model (Ref. 112) allows the
user to generate cost functions for a
range of disposal unit sizes. From the
functions, EPA predicted the
incremental costs or savings from a
change in volume brought about by
treatment. EPA assumed for all on-site
disposal scenarios that a landfill or
surface impoundment contains only one
waste.
(B) Off-site costs. For calculating the
cost of sending waste off-site, EPA
considered the cost of shipping the
waste, the price "of treating and
disposing of it, and the savings from
closing the existing on-site disposal unit
In considering off-site treatment, the
price charged by commercial waste
managers largely determines whether a
decision maker can save money by
sending waste off-site for treatment
EPA estimated off-site treatment and
disposal costs from a price survey of
selected treatments at commercial
facilities. "Review of Activities of Firms.
in the Commercial Waste Management
Industry: 1983 Update" (Ref. 119).
Transportation costs were obtained
from existing models of hazardous
waste transportation costs cited in the
WET Model (Ref. 118). The total price
for commercial treatment was estimated
as the product of the unit price and the
volume treated (which was available
from the facility database).
EPA assumed that all residuals from
treatment were disposed at the
commercial facility. Using a fiat rate of
S200 per metric ton and multiplying this
price by the residual volume gave the
total price for landfilling the residual at
a commercial facility.
In estimating off-site costs,
transportation was an important factor
in determining whether it would be more
cost-effective to petition for a variance.
In estimating transportation prices,
distances between generators and
commercial facilities were considered.
EPA assumed that the waste would be
shipped to the nearest commercial
hazardous waste management facility
and data from the 1981 OSW Survey
and "Industrial and Hazardous Waste
Management Firms 1985" (Ref. 116 and
61) was used to estimate these
distances.
EPA obtained an estimate of the
average capacity of trucks driving these
distances, hauling hazardous waste from
the WET model. The average capacity of
stake trucks was 10.6 metric tons (MT)
and 12 MTfor tankers. Due to a lack of
better information, EPA assumed that
waste volumes greater than average
shipment sizes were shipped in vehicles
filled only to this average, while
volumes less than the average were
shipped in trucks containing only that
lower volume. Therefore, smaller
"volume shipments resulted in higher
costs per mile.
Annual transportation costs were
estimated for each facility-waste
combination.
iii. Probability of being granted a
variance. After selecting the least-cost
treatment option (on- or off-site), EPA
compared the expected cost of
petitioning and being granted a variance
with the expected cost of complying
with treatment standards. The results of
this comparison formed the basis for the
Agency's estimates of the number of
petitions expected and the savings from
use of the variance.
EPA assumed that a generator's
decision whether or not to submit a
petition would be driven by the
expected varae of the cosf of various
options. As a result, changes in the
probability that a petition would be
granted affected the estimated number
of petitions submitted, the total cost, -
and the savings.
The range of probabilities that EPA
used in the analysis (P=l, .5, and .1)
represented factors that could not be
quantified easily or were not well
defined, which could still affect whether
a variance was granted. For example,
the probability could reflect the fact that
even though a petitioner submitted
information with a high degree of
certainty and met the performance
standard based on this information, the
site could never be adequately
characterized despite the best efforts
made.
The probability, also represents the
petitioner's perceptions of the chance
that EPA would find the demonstration
acceptable. The probability is most
affected by guidance given to potential
petitioners by EPA about the
information required in petitions and the
level of detail involved in petitioa
review.
c. Limitations of the analysis—L Dak
limitations. EPA had information on
waste types, volumes, and site
characteristics for 96 landfills and
surface impoundments. EPA
extrapolated this information to the
regulated community. However, thd
sample facilities do not represent a
statistically random sample of all
landfills and surface impoundments i
therefore, may not be truly
representative of the regulated
population.
The effect is that the analysis may
have understated the total number of
petitions and savings for at least two
reasons. First, it did not consider
petitions from generators whose waste
is disposed of in waste piles, and/or by |
land application. Second, it excluded
consideration of petitions for D001
wastes (ignitables).
Due to lack of information about the
constituent composition of each
facility's wastes and hydrogeologic
parameters and models that EPA will
use in making the ban decisions, the
Agency assumed that ail wastes in the
sample population were banned. This
may overestimate the number of
petitions expected.
ii. Analytical limitations. In the i
of the analysis EPA made several
assumptions that affect the results. In
determining the facilities that would
pass a preliminary risk screen, EPA
assumed a worst-case release scenario,
where all landfills and surface
impoundments were unlined. This
assumption may underestimate the
number of units where land disposal
would present only a negligible risk.
By specifying that a generator will
either petition or accept the ban, EPA
assumed that although the ban
regulations will impose additional costs
on the regulated community, the
increased costs will not affect the
volume or type of wastes generated.
This assumption ignores the possibility
that generators will alter their
production process to decrease volume
and/or toxicity of their waste. For the
short-term this assumption is
reasonable, but over longer periods,
such changes in processes are likely, but
difficult to predict.
In looking at costs of on- and off-site
.treatment and disposal, and the costs of
preparing a petition, EPA estimated the
costs based on the volume of each
individual waste. This approach ignored
the generator's ability to take advantage
of economies of scale in disposing and
treating wastes. This led to an
overestimate of the incremental unit
-------
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Federal Register / Vol. 51. No, 9-/ Tuesday, January 14, 198(5 / Proposed Rules
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Compounds from Hazardous Wastes."
National Technical Information Service
(NTIS) PB 85-117-034. May 1984.
(47) Francis. C.W. et al. "Mobility of Toxic
Compounds from Hazardous Wastes: Phase II
Comparison of Three Test Methods to a
Lysimeter Model." In Press.
(48) Freeze, R.A. and J.A. Cherry.
Groundwater. Prentice-Hall Inc., New Jersey,
1979. '
(49) Gelhar, L.W., A. Mantoglou. C. Welty,
and K.R. Rehfeldt. "A Review of Field Scale
Subsurface Solute Transport Processes Under
Saturated and Unsaturated Conditions. (Draft
Report);" Electric Power Research Institute,
Groundwater Studies, EPRIEA-CCCC. Palo
Alto, California, 1985.
(50) Griffin, R.A., B.L. Herzog, T.M.
Johnson, W.J. Morse, R.E. Hughes, S.F.J. Chou
and L.R. Follmer. "Mechanisms of
Contaminant Migration Through a Clay
Barrier—Case Study. Wilsonville, Illinois."
pp. 27-38. In: Proceedings of the Eleventh
Annual Research Symposium. Cincinnati,
Ohio. U,S. EPA. Office of Research and
Development. EPA-600/9-85-013,1985!
[51) Guven, O.. F.J. Molz, and J.G. Melville.
"An Analysis of Dispersion in a Stratified
Aquifer." Water Resources Research"
20:1337-1354,1984.
(52)'Harleman. D.R.F. "Transport Processes
in Water Quality Control." Massachusetts
Institute of Technology, Department of Civil
Engineering, Lectures in Water Quality
Control, 1970, revised 1973.
(53) Haxo, H.E-. "Testing of Materials for
Use in Lining Waste Disposal Facilities." pp.
269-292. In: Hazardous Solid Waste Testing,
First Conference (R.A. Conway and B.C.
Malloy, editors.) American Society of Testing
Materials (ASTM) Special Technical
Publication 760, ASTM Publication Code
Number (PCN) 04-760000-16, ASTM.
Philadelphia. Pennsylvania. 1981.
(54) Haxo, H.E. "Analysis and
Fingerprinting of Unexposed Polymeric
Membrane Liners." pp. 157-171. In:
Proceedings of the Ninth-Annual Research
Symposium. U.S. EPA, Office of Research and
Development. EPA-600/9-83-018,1983.
(55) Haxo, H.E., R.S. Haxo, N.A. Nelson,
P.D. Haxq, R.M. White and S. Dakessian.
"Final Report: Liner Materials Exposed to
Hazardous and Toxic Wastes." Prepared for
U.S. EPA, Office of Research and
Development, NTIS.PB 85-121-333,1984.
-------
Federal Register / Vol. SI, No. 9 / Tuesday, January 14, 1986 / Proposed Rules 1745
Robert Morris Associates and Dun &
Bradsfreefs "Industry Norms."
b. Request for public comments. EPA
recognizes that due to constraints of
time and data availability, this analysis
has significant limitations. Specifically,
EPA requests comment on the following:
i. EPA would like to refine the
assumption that 100 percent of the costs
- imposed on commercial hazardous
waste facilities can be passed through in
the from of higher prices. The Agency
requests any estimates of typical profit
margins in the commercial hazardous
waste industry, data on waste
management fees, and on the percent
price increase, in waste management
fees which may force substitution on
generators.
ii. The Agency requests public
comment and data on the feasibility of
small business waste recycling,
reclamation, or in-process reduction. In
particular, EPA requests data from the
solvent reclaiming industry and other
reclaiming services applicable to RCRA-
regulated wastes.
iii. The Agency's analysis asumes that
all affected wastes are banned from
land disposal. This assumption
overstates the quantity of wastes
banned from land disposal, and, hence,
economic impact. EPA has made this
assumption because severe time
constraints imposed by the schedule
legislated for this regulation prevented
the incorporation of treatment "
standards. Given the relative
restrictiveness of these standards,
however, this overestimate may be
minor. For the final rule, treatment
standards will be applied to determine
which waste streams will be covered
under this regulation. EPA estimate of
impacts will remain uncertain, however,
because of the lack of data on waste
composition and teachability of
constituents. EPA requests any data on
typical waste stream composition which
could allow a better assessment of how
treatment standards will constrain
disposal and treatment options.
iv. EPA requests comments and data
on alternative technologies or in-process
waste reductions available. *
This proposed rule was submitted to
the Office of Management and Budget
(OMB) for review, as required by
Executive Order 12291.
B. Regulatory Flexibility Act
Under the Regulatory Flexibility Act, 5
U.S.C. 6O1 et seq., whenever an agency
is required to issue for publication in the
Federal Register any proposed or final
rule, it must prepare and make available
for public comment a Regulatory
Flexibility Analysis which describes the
impact of the rule on small entities (i.e.,
small businesses, small organizations,
and small governmental jurisdictions)
unless the agency's administrator
certifies that the rule will not have a
significant economic impact on a
substantial number of small entities.
The Agency has examined the
proposed rule's potential impacts on
small business and has concluded that
this regulation will not have a
significant impact on a substantial
number of small entities.
This small business analysis excludes
generators of large quantities of RCRA
wastes, as it was not possible to
determine the economic size of these
firms (Ref. 6). The small business
population examined here includes two
groups: all noncommercial treatment,
storage, and disposal facilities
employing fewer than 50 persons, and
all small quantity generators which are
also small businesses. Of TSDFs, 244 are
small businesses. Of these, 84 exceed
the 5 percent ratio on costs of
production or cash from operations or
both. This represents 34 percent of the
total small business population. Of all
noncommercial facilities, 42 percent (175
out of 413) are predicted to experience
economic impacts. Among larger
businesses, 91 out of .169. or 54 percent,
may experience economic impacts.
Of the total of 25,636 small quantity
generators examined in this analysis,
the vast majority (19,709 or 77 percent of
the total population of SQGs) are also
small businesses. None of the economic
ratios examined for SQGs exceeded 1
percent on either costs of production or
cash from operations. Thus, for the
whole population of small businesses,
economic impacts did not exceed 0.6
percent.
Accordingly, I hereby certify that this
proposed rule will not have a significant
impact on a substantial number of small
entities. Therefore, this proposed rule
does not require a Regulatory Flexibility
Analysis.
C. Paperwork Reduction Act
The Paperwork Reduction Act of 1980,
44 U.S.C. 3501 et seq., requires that the
information collection requirements of
proposed and final rules be submitted to
the Office of Management and Budget
(OMB) for approval. This proposed rule
would indirectly affect another
information collection requirement that
has been approved by OMB under the
Paperwork Reduction Act. This affected
requirement has been assigned the OMB
Control Number 2050-0012. The
appropriate changes to this requirement
have been submitted to OMB for .
approval.
The information collection
rquirements directly associated with
today's proposed rule have been
submitted for OMB approval. Submit
comments on these requirements to the
Office of Informtion and Regulatory
Affairs, OMB, 730 Jackson Place. NW..
Washington, D.C. 20503, marked:
Attention: Desk Officer for EPA. The
final rule will respond to any OMB or
public comments on the information
collection requirements.
XII. References
Background Documents
(1) U.S. EPA. "Background Document for •
the Comparative Risk Assessment, to Support!
40 CFR Part 268, Land Disposal Restrictions." *
U.S. EPA, OSW, Washington. D.C., 1985.
(2) U.S. EPA. "Background Document for
the the Ground Water Screening Procedure,
to Support 40 CFR Part 268, Land Disposal
Restrictions." U.S. EPA, OSW, Washington,
D.C., 1985.
(3) U.S. EPA. "Background Document on
the Development and Use of Reference
Doses, to Support 40 CFR Part 288, Land
Disposal Restrictions." U.S. EPA, OSW,
Washington, D.C., 1985.
(4) U.S. EPA. "Background Document for
Solvents, to Support 40 CFR Part 268, Land
Disposal Restrictions." U.S. EPA. OSW,
Washington, D.C., 1985.
(5} U.S. EPA. "Background Document for
the Surface Water Screening Procedure, to
Support 40 CFR Part 268, Land Disposal
Restrictions." U.S. EPA. OSW, Washington.
D.C., 1985.
Regulatory Impact Analyses
(6) U.S. EPA. "Draft Regulatory Analysis of
Proposal Restrictions, on Land Disposal of
Hazardous Wastes." U.S. EPA, OSW,
Washington, D.C., 1985.
(7) U.S. EPA. "Cost Analysis of Variances
to Land Disposer Bans, Final Report." U.S.
EPA, OSW, Washington, D.C., 1985.
(8) U.S. EPA. "Regulatory Analysis of '
Proposed Restrictions on Land Disposal of
Certain Dioxin-Containing Wastes." U.S.
EPA, OSW, Washington, D.C., 1985.
(9) U.S. EPA. "Regulatory Analysis of
Proposed Restrictions on Land Disposal of
Certain Solvent Wastes." U.S. EPA, OSW,
Washington, D.C., November 15,1985.
Guidance Documents
(10) Boor-Allen ft Hamilton, Inc. "Petition
Reviewers' Procedures Manual—Petition for
a Land Disposal Variance Based on a
Demonstration of No Migration." Prepared
for U.S. EPA, OSW, under EPA Contract No.
68-01-6871,1985.
(11) ICF, Inc. "Draft Superfund Public
Health Evaluation Manual." Prepared for U.S.
EPA, Office of Emergency and Remedial
Response, under EPA Contract No. 68-01-
7090, October 1.1985.
(12) SCS Engineers, Inc. "Land Disposal
Ban Variance Petitioners' Guidance Manual."
Prepared for U.S. EPA, OSW. under EPA
Contract No. 68-01-6821,1985.
Other Reference*
(13) Ambrose, R.B.. L. Mulkey, and P.S.
Huyakom. "Methodology for Assessing
-------
1758
/ Vol 51. No. » / Tae^fay. Japu«y 1*. 1986 /
Lining of.Hazardous Waalft.SectM» 261J
Hazardous Wastes from Nonspecific
Sources: F001-F005." US. EPA. OSW
Washington, D.C., 196a
(101) US. EPA.' "Descriptions of Sites on
Current National Priorities LwC" p. 6. US.
EPA, Office of Emergency and Remedial
Response, Washington, D.C. 1984
(102) U.S. EPA. "Development of Land
Disposal Banning Decisions Under
Uncertainty." U.S. EPA. Athens
Environmental Research Laboratory, Athens
GA. 1985.
(103) U.S. EPA. "Dioxin Strategy." US
EPA, Office of Water Regulations and
Standards and Office of SoHd Waste and
Emergency Response, Washington, D.C., 1983
(103a) U.S. EPA. "Dfojcin Listing
Background Document." U.S. EPA, OSW.
Washington, D.C., January 1985.
(104) U.S. EPA. "Effects of Organic
Solvents OB the Permeability of Clay Soils."
Prepared by K.W. Brown and D.C. Anderson
for US. EPA. EPA-
-------
Federal Register / Vol: 51; No. 9 / Tuesday, January 14, 1986 / Proposed Rules
174
156) Haxo, RE; Jr.. N.A. Nelson and J.A.
Miedema. "Solubility Parameters for
Predicting Membrane-Waste Liquid
Compatibility." pp. 198-212. In: Proceedings
of the Eleventh Annual Research Symposium.
U.S. EPA. Office of Research and
Development. EPA-600/9-85-013,1985.
(57) Hughes, T.H.. K. Brooks, W. Morris. B.
Wilson. B. Roche. "A Descriptive Survey of
Solucted Organic Solvents, Open-File
Report." The University of Alabama,
Environmental Institute for Waste
Management Studies. Tuscaloosa, Alabama,
1985.
(58) Huyakorn, P.S., M.J. Ungs, E. D.
Sudicky, LA. Mulkey, and T.D. Wadsworth.
"RCRA Hazardous Waste Identification and
Land Disposal Restrictions Groundwater
Screening Procedure." Prepared for U.S. EPA,
OSW under EPA Contract No. 68-01-7075.
June 1985.
(59) IARC (International Agency for
Research on Cancer). "IARC Monographs on
the Evaluation of the Carcinogenic Risk of '
Chemicals to Humans, Supplement 4." IARC,
Lyon, France. 1982.
(60) ICF. Inc. "Scoping Analysis for RCRA
Section 3005(j)(ll)." Prepared for U.S. EPA,
OSW. under EPA Contract No. 68-01-6621
June 1985.
(61) Industrial and Hazardous Waste
Management Firms. "Industrial and
Hazardous Waste Management Firms, 1984
Environmental Information Limited,
Industrial and Hazardous Waste
Management Firms, 1984." 1985.
(62) Israelsen, O.W. and V.E. Hansen.
Irrigation Principles and Practices. John
Wiley and Sons, Inc., New York, 1962.
(63) Jackson, D.R., et al. "Adsorption/
Desorption of 2,3,7,8-TCDD in Contaminated
Soils." Prepared by Battelle Columbus "
Laboratory, for U.S. EPA, Office of Research
and Development, under EPA Contract No.
68-03-3100. Presented at the EPA Hazardous
Waste Engineering Research Laboratory, llth
Annual Research Symposium, Cincinnati.
OH. April 29-May 1.1985.
(64) Jacobs Engineering. "Time
Requirements for the Siting, Permitting, and
Construction of New Hazardous Waste
Treatment Facilities." Prepared for U.S. EPA,
OSW, under EPA Contract No. 68-01-7053.
December. 1985.
(65) Karickhoff, S. W. "Sorption Protocol
Evaluation for OSW Chemicals." U.S. EPA;
Athens Environmental Research Laboratory,
Athens, GA, 1985.
(66) Karickhoff, S.W^P-S. Brown, and T.A.
Scott. "Sorption of Hydrophobic Pollutants on
Natural Sediments.1' Water Res. 13:241-248,
1979.
(67) Lee, A. "Analysis of Technical
Information to Support RCRA Rules for
Dioxina—Containing Waste Streams
(Hazardous Waste Nos. F020. F021,.F022y
F023. F026, F027. and F028.)" Prepared by
Technical Resources. Inc., for U.S. EPA,
Office of Reseach and Development, under
EPA Contract No. 5W-6242-NASX, July 1985.
(68) Lehman, A.J. and O.J. Fitzhugh. "One
Hundredfold Margin of Safety." Assoc. of
Food Drug Officers. U.S. Quarterly Bulletin
18:33-35,1954.'
(69) Lindberg. R.D., and D.D. Runnells.
"Groundwater Redox Reactions: An Analysis-
of Equilibrium State Applied to Eh
Measurements and Geochemical Modeling,"
Science 225:925.1984.
(70) Liss, P.S. "Processes of Gas Exchange
Across an Air-Water Interface." Deep-Sea
Research 20:221-238,1973.
(71) Lord, A.E., Jr., R.M. Koerner and E.G.
Lindhul*. "Chemical Mass Transport
Measurements to Determine Flexible
Membrane Liner Lifetime." pp. 313-320. In:
Proceedings of the Eleventh Annual Research
Symposium. U.S. EPA, Office of Research and
Development. EPA-fl00/9-85-O13.1985.
(72) Macey, H.H. "Clay-Water
Relationships-and the Internal Mechanisms
of Drying." Transactions, British Ceramic
Society 41:73-121,1942.
(73) Mackay, D.M., P;V. Roberts, and J.A.
Cherry. "Transport of Organic Cpntaminants
in Groundwater." Environmental Science and
Technology 19:384-392,1985. .
(74) Mark, H.F., N.G. Gaylord, and N.M.
Bikales. Encyclopedia of Polymer Science
and Technology. John Wiley and Sons, Inc.,
New York, 1964.
(75) Mashni. C.I., H.P. Warner and W.E.
Grube, Jr. "Laboratory Determinations of
Dielectric Constant and Surface Tension as
Measures of Leachate/Liner Compatibility."
In: Proceedings of the Eleventh Annual
Research Symposium, U.S. EPA, Office of
Research and Development. EPA-600/9-85-
013,1985.
(76) McCarty, P.L. "Organics in Water—an
Engineering Challenge." Journal ef
Environmental Engineering Division, 106,
EE1, February 1980.
(77) Midwest Research Institute.
"Performance Evaluation of Full-Scale
Hazardous Waste Incinerators, Vol. IV,
Appendices C through J." Prepared for U.S.
EPA, Office of Research and Development,
under EPA Contract No. 68-01-3177, August
28,1984.
(78) Mitre Corp. "Composition of
Hazardous Waste Streams Currently
Incinerated." Prepared for U.S. EPA OSW,
under EPA Contract No. 68-01-6092, April
1983.
(79) Molz. F.J., O. Guven, and J.G. Melville.
"An Examination of Scale-Dependent
Dispersion Coefficients." Groundwater
21:715-725.1983.
(80) Morel, F.M.M., J.C. Westall, CR.
O"Melia, and J.J. Morgan. "Fate of Trace
Metals in Los Angeles County Wastewater
Discharge." Environmental Science and
Technology 9:756; 1975.
(81) National Research Council. "Drinking"
Water and Health." Volume 4v Safe Drinking
Water Committee, National Academy Press,
Washington, D.C.. 1982-.
(82). Park, CC, "World-Wide Variations in
Hydraulic Geometry Exponents of Stream
Channels: An Analysis and Some
Observations." Journal of Hydrology 33:133-
149,1977.
(83) Pickens, J.F. and G.E. Grisak. "Scale-
Dependent Dispersion in a Stratified
Granular Aquifer." Water Resources
Research 17:1191-1211,1981.
(84) Pickens. J.F. and.G.E. Grisak. .
"Modeling of Scale-Dependent Dispersion in
Hydrogeologic Systems." Water Resources
Research 17:1701-1711,1981.
(85) Reckhow, K.H. and S.C. Chapra.
"Engineering Approaches for Lake •
Management, Volume i. Data Analysis and
Empirical Modeling." Ann Arbor Science
Publishers, Inc., Michigan, 1983.
(86) Reckhow, K.H., C.M. Marin, and R.T.
DiGiulio. 'Technical Assistance in the
Development of the Monte Carlo Uncertaint;
Analysis for the Surface Water Component
for Land Disposal Restrictions,
Determinations. Draft Report, October 29,
1985." Prepared for U.S. EPA, OSW under
Contract No. 68-01-7075.
(87) Rowe, William D. An Anatomy ofRis
John Wiley and Sons. Inc., New York, 1977.
(88) Sauty, Jean-Pierre. "An Analysis of
Hydrodispersive Transfer in Aquifers."
Water Resources Research 16:145-158,1980. |
(89) Schram, M. "Permeability of Soils to
Four Organic Solvents and Water." M.S.
Thesis, University of Arizona, Tucson,
Arizona, 1981.
(90) Schwope, A.D., P.P. Costas, W.J.
Lyman. "Draft Report—Prediction, of Waste/ |
Leachate Resistance of Flexible Membrane
Liners." Prepared by A.D. Little, Inc., for U.S. |
EPA, Office of Water Regulation and
Standards, 1985.
(91) Sidwell, V.D., "Chemical and
Nutritional Composition to Finfishes, WhalesJ
Crustaceans, Mollusks, and Their Products."
National Oceanographic and Atmospheric
Administration, Technical Memorandum,
NMFS F/SEC-11,1981.
(92) Siedl, G. and K. Ballschmifer.
"Isolation of PCB's from Soil-Recovery Rates |
Using Different Solvent System."
Chemosphere No. 5, pp. '373-378 (Elmsford,
NY: Pergamon Press, 1976), as referenced in
Design of Land Treatment Systems for
Industrial Wastes—Theory & Practice. M.R.
Overcash & D. Pal, Ann Arbor Science
Publishers, Inc., Michigan. 1981.
(93) "State of Illinois Court Orders:
Exhumation of Wastes from Landfill".
Hazardous Materials Intelligence Report,
Illinois hearing transcript, March 5.1982.
(94) Sudicky, EJV, J.A. Cherry, and E. O.
Frind. "Migration of Contaminants in
Groundwater at a Landfill: A Case Study."
Journal of Hydrology, 63:81-108,1983.
(95) Surprenant. N., et al. "Land Disposal
Alternatives for Certain Solvents—Final
Report." Prepared by GCA Corporation for
U.S. EPA, OSW, under EPA Contract No. 88-
02-3168, January 1984. .
(96) Tratnyek. J.P,, P.P. Costas and W.J.
Lyman. "Test Methods for Determining the
Chemical Waste Compatibility of Synthetic
Liners. Final Report." Prepared for U.S. EPA.
Office of Research and Development, under •
EPA Contract No. 68-01-6160; 1984.
(97) U.S. EPA. Acceptable Daily Intake
Workgroup Paper: "Assessing Risks
Associated with Systemic Toxicants."
(98) U.S. EPA. "Alternate Concentration
Limit Guidance Based on Section 264.94b
Criteria. Part I. Information Required in ACL
Demonstrations, Draft." June, 1985.
(99) U.S. EPA. "Appendix C—Guidelines
and Methodology Used in the Preparation of
the Health Effects Chapters of the Consent
Decree, Water Criteria Documents", 45 FR
79347, November 28,1980.
(100) U.S. EPA. "Background Document,
Resource Conservation and Recovery Act,
Subtitle C., Section 3001, Identification and
-------
the solid phase "of the waste (as
determined using glass fiber filter
filtration), is extracted. This will insure
that there is adequate extract for the
required analyses (e.g.. semivolatiles,
metals, pesticides and herbicides).
The determination of which extraction
fluid to use (See Step 7.12) may also be
conducted at the start of this procedure.
This determination shall be on the solid
phase of the waste (as obtained using
glass fiber filter filtration).
7.1 If the waste will obviously yield
no free liquid when subjected to
pressure filtration, weigh out a
representative subsample of the waste
(100 gram minimum) and proceed to
Step 7.11.
7.2 If the sample is liquid or
multiphasic, liquid/solid separation is
required. This involves the filtration
device discussed in Section 4.3.2, and is
outlined in Steps 7.3 to 7.9.
7.3 Pre-weigh the filter and the
container which will receive the filtrate.
7.4 Assemble filter holder and filter
following the manufacturer's
instructions. Place the filter on the
support screen and secure. Acid wash
the filter if evaluating the mobility of
metals (See Section 4.4):
7.5 Weigh out a representative
subsample of the waste (100 gram
minimum) and record weight.
7.6 Allow slurries to stand to permit
the solid phase to settle. Wastes that
settle slowly maybe centrifuged prior to
filtration.
7.7 Transfer the waste sample- to the
filter holder.
Note.—If waste material has obviously
adhered to the container used to transfer the
sample to the filtration apparatus, determine
the weight of this residue and subtract it from
the sample weight determined in Step 7.5, to
determine the weight of the waste sample
which will be filtered.
Gradually apply vacuum or gentle
pressure of 1-10 psi. until air or
pressurizing gas moves through the
filter. If this point is not reached under
10 psi, and if no additional liquid has
passed through the filter kt any 2 minute
interval, slowly increase the pressure in
10-psi increments to a maximum of 50
psi. After each incremental increase of
10 psi, if the pressurizing gas has not
moved through the filter, and if no
additional liquid has passed through the
filter in any 2 minute interval, proceed
to the next 10 psi increment. When the
pressurizing gas begins to move through
the filter, or when liquid flow has ceased
at 50 psi (i.e., does not result in any
additional filtrate within any 2 minute
period), filtration is stopped.
Note.—Instantaneous application of high
pressure can degrade the glass fiber filter.
and may cause premature plugging.
7.8 The material in the filter holder is
defined as the solid phase of the waste,
and the filtrate is defined as the liquid
phase. ".-.:':'?•'* \ "'• ~f>"'
Note.—Some wastes, such as oily wastes
and some paint wastes, will obviously
contain some material which appears to be a
liquid—but even after applying vacuum or
pressure filtration, as outlined in Step 7.7, this
material may not filter. If this is the case, the
material within the filtration device is
defined as a solid, and is carried through the
extraction as a solid.
7.9 Determine the weight of the
liquid phase by subtracting the weight of
the filtrate container (See Step 7.3) from
the total weight of the filtrate-filled
container. The liquid phase may now be
either analyzed (See Step 7.15) or stored
at 4° C until time of analysis. The weight
of the soBd phase of the waste sample is
determined by subtracting the weight of
the liquid phase from the weight of the
total waste sample, as determined in
Step 7.5 or 7.7. Record the weight of the
liquid and solid phases.
Note.--If the weight of the solid phase of
the waste is iess than 75 grams, review Steo
7.0
7.10 The sample will be handled
differently from this point, depending on
whether it contains more or less than
0.5% solids. If the sample obviously has
greater than 0.5% solids go to Step 7.11.
If it appears that the solid may comprise
less than 0.5% of the total waste, the
percent sofids will be determined as
follows:
7.10.1 Remove the solid phase and
filter from the filtration apparatus.
7.10.2 Dry the filter and solid phase
at 100±* C ontil two successive
weighings yield the same value. Record
final weight.
7.10.3 Calculate the percent sol ids a s
follows:
weight pf dry waste and
filters—tared' weight of filters
initial weight of waste (Step 7.5 or
7.7)
x 100= percent solids'
7.10.4 If the solid comprises less than
0.5% of the waste, the solid is discarded
and the liquid phase is defined as the
TCLP extract. Proceed to Step 7.14.
7.10.5 If the solid is greater than or
equal to 03% of the waste, return to Step
7.1. and begin the procedure with a new
sample of waste. Do not extract the
solid that has been dried.
Note.—This step is only used to determine
whether the solid must be extracted, or
whether it may be discarded unextracted..It
is not used in calculating the amount of
extraction fluid to use in extracting the
waste, nor is the dried solid derived from this
step subjected to extraction. A new sample
will have to be prepared" for extraction.
7.11 If the sample has more than
0.5% solids, it is now evaluated for
particle size. If the solid material has a
surface area per gram of material equal
to or greater than 3.1 cm2, or is capable
of passing through a 9.5 mm (0.375 inch)
standard sieve, proceed to Step 7.12. If
the surface area is smaller or the
particle size is larger than that described
above, the solid material is prepared for
extraction by crashing, cutting, or
grinding the solid material to a surface
area or particle size as described above.
When surface area or particle size has
been appropriately altered, proceed to
Step 7.12.
7.12 This step describes the
determination of the appropriate
extracting fluid to use (See Sections 5.0
and 7.0).
7.12.1 Weigh out a small sub-sample
of the solid phase of the waste, reduce
the solid (if necessary) to a particle size
of approximately 1 mm in diameter or
less, and transfer a 5.0 gram portion to a
500 ml beaker or erlenmeyer flask.
7.12.2 And 96.5 ml distilled deionized
water (ASTM Type 2), cover with
watchglass, and stir vigorously for 5
minutes using a magnetic stirrer.
Measure and record the pH. If the pH is
<5.0, extraction fluid #1 is used.
Proceed to Step 7.13.
7.12.3 If the pH from Step 7.12.2 is >
5.0, add 3.5 ml 1.0 N HC1. slurry for 30
seconds, cover with a watchglass, heat
to 50°C, and hold for 10 minutes.
7.12.4 Let the solution cool to room
temperature and record pH. If pH is
<5.0, use extraction fluid #1. If the pH
is > 5.0. extraction fluid #2 is used.
7.13 Calculate the weight of the
remaining solid material by subtracting
the weight of the sab-sample taken for
Step 7.12, from the original amount of
solid material, as obtained from Step 7.1
or 7.9. Transfer remaining solid material
into the extractor vessel, inchiding the
filter used to separate the initial liquid
from the solid phase.
Note.—If any of the solid phase remains
adhered to the walls of the filter holder, or
the container used to transfer the waste, its
weight shall be determined, substracted from
-------
Federal Register / Vol. 51. No. 9 / Tuesday, January 14, 1986 / Proposed Rules
4.2 Extraction Vessel:
4.2.1 Zero-Headspace Extraction
Vessel (ZHE). When the waste is being
tested for mobility of any volatile
contaminants (See Table 1), an
extraction vessel which allows for
liquid/solid separation within the
device, and which effectively precludes
headspace (as depicted in Figure 3), is
used. This type of vessel allows for
initial liquid/solid separation,
extraction, and final extract filtration
without having to open the vessel-(See
Section 4.3.1). These vessels shall have
an internal volume of 500 to 600 ml and
be equipped to accommodate a 90 mm
filter. Suitable ZHE devices known as
EPA are identified in Table 3. These
devices contain viton O-rings which
should be replaced frequently.
4.2.2 When the waste is being
evaluated for other than volatile
contaminants, an extraction vessel
which does not preclude headspace
(e.g., 2-liter bottle) is used. Suitable
extraction vessels include bottles made
from various materials, depending on
the contaminants to be analyzed and the
nature of the waste (See Section 4.3.3).
These bottles are available from a
number of laboratory suppliers. When
this type of extraction vessel is used, the
filtration device discussed in Section
4.3.2 is used for initial liquid/solid
separation and final extract filtration.
4.3 Filtration Devices:
4.3.1 Zero-Headspace Extractor
Vessel (See Figure 3): When the waste is
being evaluated for volatiles, the zero
headspace extraction vessel.is used for
filtration. The device shall be capable of
supporting and keeping in place the
glass fiber filter, and be able to
withstand the pressure needed to
accomplish separation (50 psi).
Note.—When it is suspected that the glass
fiber filter has been ruptured, and in-line
glass fiber filter may be used to filter the
extract.
4.3.2 Filter Holder. When the waste
is being evaluated for other than volatile
compounds, a filter holder capable of
supporting a glass fiber filter and able to
withstand the pressure needed to
accomplish separation is used. Suitable
filter holders range from simple vacuum
units to relatively complex systems
capable of exerting pressure up to 50 psi
and more. The type of filter holder used
depends on the properties of the
material to be filtered (See Section'
4.3.3). These devices shall have a
minimum internal volume of 300 ml and
be equipped to accommodate a
minimum filter size of 47 mm. Filter
holders known to EPA to be suitable for
use are shown in Table 4. '
4.3.3 Materials of Construction.
Extraction vessels and filtration devices
shall be made of inert materials which
will not leach or absorb waste
components. Glass,
polytetrafluoroethylene (PTFE), or type
316 stainless steel equipment may be
used when evaluating the mobility of
both organic and inorganic components.
Devices made of high density
polyethylene (HOPE), polypropylene, or
polyvinyl chloride may be used when
evaluating the mobility of metals.
4.4 Filters: Filters shall be made of
borosilicate glass fiber, contain no
binder materials, and have an effective
pore size of 0.6-0.8 /im, or equivalent.
Filters known to EPA to meet these
specifications are identified in Table 5.
Pre-filters must not be used. When
evaluating the mobility of metals, filters
shall be acid washed prior to use by
rinsing with 1.0 N nitric acid followed by
three consecutive rinses with deionized
distilled water (minimum of 500 ml per
rinse). Glass fiber filters are fragile and
should be handled with care.
4.5 pH Meters: Any of the commonly
available pH meters are acceptable.
4.6 ZHE extract collection devices:
TEDLAR* bags or glass, stainless steel
or PTFE gas tight syringes are used to
collect the initial liquid phase and the
final extract of the waste when using the
ZHE device.
4.7 ZHE extraction fluid collection
devices: Any device capable of
transferring the extraction fluid into the
ZHE without changing the nature of the
extraction fluid is acceptable (e.g., a
constant displacement pump, a gas tight
syringe, pressure filtration unit (See
Section 4.3.2), or another ZHE device).
4.8 Laboratory balance; Any
laboratory balance accurate to within ±
0.01 grams may be used (all weight
measurements are to be within ± 0.1
grams).
5.0 Reagents
5.1 Water: ASTM Type 1 deionized,
carbon treated, decarbonized, filtered
'water (or equivalent water that is
treated to remove volatile components)
shall be used when evaluating wastes
for volatile contaminants. Otherwise,
ASTM Type 2 deionized distilled water
(or equivalent) is used. These waters
should be monitored periodically for
impurities.
5.2 1.0 N Hydrochloric acid (HCl)
made from ACS Reagent grade.
5.3 1.0 N Nitric acid (HNOs) made
from ACS Reagent grade.
5.4 1.0 N Sodium hydroxide (NaOH)
made from ACS Reagent grade.
TEDLAR is a registered trademark of PuPont.
5.5 Glacial acetic acid (HOAc) i
from ACS Reagent grade.
5.6 Extraction fluid:
5.6.1 Extraction fluid No. 1: This fluil
is made by adding 5.7 ml glacial HOAc
to 500 ml of the appropriate water (See
Section 5.1), adding 64.3 ml of 1.0 N
NaOH, and diluting to a volume of 1
liter. When correctly prepared, the pH ol
this fluid will be 4.93 ± 0.05. |
5.6.2 Extraction fluid No. 2: This flud
is made by diluting 5.7 ml glacial HOAcl
with ASTM Type 2 water (See Section
5.1) to a volume of 1 liter. When
correctly prepared the pH of this fluid
will be 2.88 ± 0.05.
Note.—These extraction fluids shall be
made up fresh daily. The pH should be
checked prior to use to insure that they are
made up accurately, and use these fluids
should be monitored frequently for
impurities.
5.7 Analytical standards shall be
prepared according to the appropriate
analytical method.
6.0 Sample Collection, Preservation,
and Handling
6.1 All samples shall be collected
using a sampling plan that addresses the|
considerations discussed in "Test
Methods for Evaluating Solid Wastes"
(SW-846).
6.2 Preservatives shall not be added
to samples.
6.3 Samples can be refrigerated
unless it results in irreversible physical
changes to the waste.
6.4 When the waste is to be
evaluated for volatile contaminants,
care must tie taken to insure that these
are not lost. Samples shall be taken and
stored in a manner which prevents the
loss of volatile contaminants. If
possible, any necessary particle size
reduction should be conducted as the
sample is being taken (See Step 8.5).
Refer to SW-846 for additional sampling
and storage requirements when volatiles
are contaminants of concern.
6.5 TCLP extracts should be
prepared for analysis and analyzed as
soon as possible following extraction. If
they need to be stored, even for a short
period of time, storage shall be at 4°C
and samples for volatiles analysis shall
not be allowed to come into contact
with the atmosphere (i.e., no
headspace).
7.0 Procedure When Volatiles Are Not
Involved
Although a minimum sample size of
100 grams is required, a larger sample
size may be necessary, depending on the
percent solids of the waste sample.
Enough waste sample should be
collected such that at least 75 grams of
-------
1754
Federal Register / Vol. 51. No. 9 / Tuesday. January 14. 1986 / Proposed Rules
When surface area or particle size has-
been appropriately altered, the solid is
recombined with the rest of the waste.
8.6 Waste slurries need not be
allowed to stand to permit the solid
phase to settle. Wastes that settle
slowly shall not be centrifuged prior to
filtration.
8.7 Transfer the entire sample (liquid
and solid phases) quickly to the ZHE.
Secure the filter and support screens
into the top flange of the device and
secure the top flange to the ZHE body in
accordance with the manufacturers
instructions. Tighten all ZHE fittings and
place the device in the vertical position
(gas inlet/outlet flange on the bottom).
Do not attach the extract collection
device to the top plate.
Note.—If waste material has obviously
adhered to the container used to transfer the
sample to the ZHE, determine the weight of
this residue and subtract it from the sample
weight determined in Step 8.4, to determine
the weight of the waste sample which will be
filtered.
Attach a gas line to the gas inlet/outlet
valve (bottom flange), and with the
liquid inlet/outlet valve (top flange)
open, begin applying gentle presssure of
1-10 psi (or more if necessary) to slowly
force all headspace out of the ZHE
device. At the first appearance of liquid
from the liquid inlet/outlet valve,
quickly close the valve and discontinue
pressure.
8.8 Attach evacuated pre-weighed
filtrate collection container to the liquid
inlet/outlet valve and open valve. Begin
applying gentle pressure of 1-10 psi to
force the liquid phase into the filtrate
collection container. If no additional
liquid has passed thrugh the filter in any
2 minute interval, slowly increase the
pressure in 10 psi increments to a
maximum of 50 psi. After each
incremental increase of 10 psi, if no
additional liquid has passed through the
filter in any 2 minute interval, proceed
to the next 10 psi increment. When
liquid flow has ceased such that
continued pressure filtration at 50 psi
does not result in any additional filtrate
within any 2 minute period, filtration is
stopped. Close the liquid inlet/outlet
valve, discontinue pressure to the
piston, and disconnect the filtrate
collection container.
Note.—Instantaneous application of high
pressure can degrade the glass fiber filter and
may cause premature plugging.
8.9 The material in the ZHE is
defined as the solid phase of the waste,
and the filtrate is defined as the liquid
phase.
Note.—Some wastes, such as oily wastes
«nd some paint wastes, will obviously
contain some material which appears to be a
liquid—but even after applying pressure
filtration, this material will not filter. If this is
the case, the material within the filtration
device is defined as a solid, and is carried
through the TCLP extraction IsTsolid.
If the original waste contained less than
0.5% solids, (See Step 8.4) this filtrate is
defined as the TCLP extract, and is
analyzed directly—proceed to Step 8.13.
8.10 Determine the Weight of the
liquid phase by subtracting the weight of
the filtrate container (See Step 8.1) from
the total weight of the filtrate-filled
container. The liquid phase may now be
either analyzed (See Steps 8.13 and
8.14), or stored at 4° C until time of
analysis. The weight of the solid phase
of the waste sample is determined by
subtracting the weight of the liquid
phase from the weight of the total waste
sample (See Step 8.4). Record the final
weight of the liquid and solid phases.
8.11 The following details how to
add the appropriate amount of
extraction fluid to the solid material
within the ZHE and agitation of the ZHE
vessel. Extraction fluid #1 is used in all
cases (See Section 5.6).
8.11.1 With the ZHE in the vertical
position, attach a line from the
extraction fluid reservoir to the liquid
inlet/outlet valve. The line used shall
contain fresh extraction fluid and should
be preflushed with fluid to eliminate any
air pockets in the line. Release gas
pressure on the ZHE piston (from the
gas inlet/outlet valve), open the liquid
inlet/outlet valve, and begin transferring
extraction fluid (by pumping or similar
means) into the ZHE. Continue pumping
extraction fluid into the ZHE until the
amount of fluid introduced into the
device equals 20 times the weight of the
solid phase of the waste that is in the
ZHE.
8.11.2 After the extraction fluid has
been added, immediately close the
liquid inlet/outlet valve, and disconnect
the extraction fluid line. Check the ZHE
to make sure that all valves are in their
closed positions. Pick up the ZHE and
physically rotate the device in an end-
over-end fashion 2 or 3 times. Reposition
the ZHE in the vertical position with the
liquid inlet/outlet valve on top. Put 5-10
psi behind the piston (if necessary), and
slowly open the liquid inlet/outlet valve
to bleed out any headspace (into a hood)
thaf may have been introduced due to
the addition of extraction fluid. This
bleeding shall be done quickly and shall
be stopped at the first appearance of
Final contaminant concentration = -
liquid from the valve. Re-pressurize the
ZHE with 5-10 psi and check all ZHE
fittings to insure that they are closed.
8.11.3 Place the ZHE in the rotary -
extractor apparatus (if it is not already
there), and rotate the ZHE at 30 ± 2 rpm
for 18 hours. The temperature shall be
maintained at 22 ± 3° C during
agitation.
8.12 Following the 18 hour
extraction, check the pressure behind
the ZHE piston by quickly opening and
closing the gas inlet/outlet valve, and
noting the escape of gas. If the pressure
has not been maintained (i.e., no gas
release observed), the device is leaking.
Replace ZHE O-rings or other fittings, as
necessary, and redo the extraction with
a new sample of waste. If the pressure
within the device has been maintained,
the material in the extractor vessel is
once again separated into its component
liquid and solid phases. If the waste
contained an initial liquid phase, the
liquid may be filtered directly into the
same filtrate collection container (i.e.,
TEDLER® bag, gas-type syringe) holding
the initial liquid phase of the waste,
unless doing so would create multiple
phases, or unless there is not enough
volume left within the filtrate collection
container. A separate filtrate collection
container must be used in these cases.
Filter through the glass fiber filter, using
the ZHE device as discussed in Step 8.8.
All extract shall be filtered and collected
if the extract is multi-phasic or if the
waste contained an initial liquid phase.
Note.—If tha glass fiber filter is not intact
following agitation, the filtration device
discussed in the NOTE in Section 4.3.1 may
. be used to filter the material within the ZHE.
8.13 If the waste contained no initial
liquid phase, the filtered liquid material
obtained from Step 8.12 is defined as the
TCLP extract. If the waste contained an
initial liquid phase, the filtered liquid
material obtained from Step 8.12, and
the initial liquid phase (Step 8.8) are
collectively defined as the TCLP extract.
8.14 The TCLP extract will be
prepared and analyzed according to the
appropriate SW-846 analytical methods,
as identified in Appendix HI of 40 CFR
261. If the individual phases are to be
analyzed separately, determine the
volume of the individual phases (to 0.1
ml), conduct the appropriate analyses
and combine the results mathematically
by using a simple volume weighted
average:
-------
Federrf Register /Vrf. 51. ffo-. 9 / Ttreaday, January 14, 1986 / Proposed Rules
the weight of the solid phase of the waste, as
determined above, and this weight is used in
calculating the amount of extraction fluid to
iidd into the extractor bottle.
Slowly add an amount of the
appropriate extraction fluid (See Step
~.12), into the extractor bottle equal to
-0 times the weight of the solid phase
ihat has bsen placed into the extractor
bottle. Close extractor bottle tightly,
riecure in cotary extractor device and
rotate at 30±2 rpm for 18 hours. The
!pinperalure.shall be maintained at
-2±3'C during extraction period.
Note.—As agitation continues, pressure
•nay build up within the extractor bottle (due
>*o the evolution of gasses such as carbon
(iioxide). To relieve these pressures, the
extractor bottle may be periodically opened
ma nufaclurer.'s instructions. Secure the
glass fiber filter between the support
screens and set aside. Set liquid inlet/
outlet flange (top flange) aside.
8.3 If the waste will obviously yield
no free liquid when subjected to
pressure filtration, weigh out a
representative subsample of the waste
(25 gram maximum—See Step 8.0),
record weight, and proceed to Step 8.5.
*8.4: This step provides the means 1
which to detemine the approximate
sample size for the ZHE device. If the
waste is liquid or multiphasic, foHow th
procedure outlined in Steps 7.2 to 7.9
(using the Section 7 filtration apparatusj
and obtain the percent solids by
dividing the weight of the solid phase ofj
the waste by the original sample size
used. If the waste obviously contains
greater than 0.5% solids, go to Step 8.4J
If it appears that the solid may corapris
less than 0.5% of the waste, go to Step
8.4.1
8.4.1 Determine the percent solids I
using the procedure outlined in Step
7.10. If the waste contains less than 0
solids, weigh out a new 100 gram
minimum representative sample,
proceed to Step 8.7, and follow until the|
liquid phase of the waste is filtered
using the ZHE device (Step 8.8). This
liquid filtrate is defined as the TCLP
extract, and is analyzed directly. If the
waste contains greater than or equal to
0.5% solids, repeat Step 8.4. using a new |
100 gram minimum sample, determine
the percent solids, and proceed to Step
8.4.Z
8.4.2 if the sample is <25% solids.
weigh out a new 100 gram minimum
representative sample, and proceed to
Step 8.5. If the sample is >25% solids,
the maximum amount of sample the
ZHE can accommodate is determined by
dividing 25 grams by the. percent solids
obtained from Step 8.4. Weigh out a new I
representative sample of the determined!
size.
8.5 After a representative sample of
the waste (sample size determined from
Step 8.4) has been weighed out and
recorded, the sample is now evaluated
for particle size (See Step 8.0). If the
solid material within the waste
obviously has a surface area per gram of
material equal to or greater than 3.1
cm2, or is capable of passing through a
9.5 mm (0.375 inch) standard sieve,
proceed immediately to Step 8.6. If the
surface area is smaller or the particle
size is larger than that described above,
the solid material which does not meet
the above criteria is separated from the
liquid phase by sieving (or equivalent
means), and the solid is prepared for
extraction by .crushing, cutting, or
grinding to a surface area or particle
size as described above.
Note.—Wastes and appropriate equipment
should be refrigerated, if possible, to 4" C
prior to particle size reduction. Grinding and
milling machinery which generates heat shall
not be usad for particle size reduction. If
reduction of the solid phase of the waste is
necessary, exposure of the waste to the
atmosphere should be avoided to the ex.tsr.1
possible.
-------
1756
FIGURE 1- TCLP Flowchart
WET w;
CONTAJ
NON-F]
SOLIDS
\STK SAMPLE | ; . ; J WET WAS
LNS < 0.5 % | REPRESENTATIVE WASTE 1 ™NTMN
LLTERABLE * | SAMPLE
i - i
1
DRY WASTE
SAMPLE
[ |»
LIQUID/SOLID |
SEPARATION |
0.6-0.8 un DISCARD
GLASS FIBER SOLID SOLID
FILTERS
1
I
1
1
1 REDUCE PARTICLE SIZE IF
\ OR SURFACE AREA <3.1
1 NON-FIL
1 SOLIDS
TE SAMPLE
S > 0.5 %
TERABLE
" LIQUID/SOLID
sor,™ SEPARATION
0.6-0.8 un
GLASS FIBER
FILTERS
LIQUID
STORE AT
4°C
1
>9.5 mm |
cm2 |
1
4>
TCLP EXTRACTION*
OF SOLID
0-HEADSPACE EXTRACTOR
REQUIRED PCiR VOLATILES
^
1
1 LIQUID/SOLID
1 ' SEPARATION
1- 0.6-0.8 un GLASS
1 FIBER FILTERS
1
LIQUID
. . r
TCLP EXTRACT
1
TCLP EXTRACT J ANALYTICAL
1 METHODS
1
-
1
1
j ^ DISCARD
SOLID
1
T
^ _ _ TCLP EXTRACT
1 ,
* The extraction fluid arplcyed is a functicn of the alkalinity of the solid
phase of the waste
-------
FederaF Register / Vol. 51, No. 9 f Tuesday, January 14, 1968 f- Proposed Rules
where:
Vi =» The volume of the first phase (1)
C< = The concentration of the contaminant of
concern in the first phase (mg/1)
V, = The volume of the second phase (I)
Ci = The concentration of the contaminant of
concern in the second phase (mg/1)
8.15 The contaminant concentrations
in the TCLP extract are compared to the
thresholds identified in the appropriate
regulations. Refer to Section 9 for
quality assurance requirements.
9.0 Quality Assurance Requirements
9.1 All data, including quality
assurance data, should be maintained
and available for reference or
inspection.
9.2 A minimum of one blank for
every 10 extractions that have been
conducted in an extraction vessel shall
be employed as a check to determine if
any memory effecis-from the extraction
equipment is occurring. One blank shall
also be employed for every new batch of
leaching fluid that is made -up.
9.3 All quality control measures
described in the appropriate analytical •
methods shall be followed.
9.4 The method of standard addition
shall be employed for each waste type
if: (1) Recovery of the compound from
spiked splits of the TCLP extract is not
between 50 and 150%, or (2) If the
concentration of the constituent
measured in the extract is within 20% of
the appropriate regulatory threshold. If
more than 1 extraction is being run on
samples of the same waste, the method
of standard addition need only be
applied once and the percent recoveries
applied to the remainder of the
extractions.
9.5 TCLP extracts shall be analyzed
within the following periods after
generation: Volatiles—14 days, Semi-
volatiles—40 days. Mercury—28 days.
and other Metals—180 days.
TABLE 1.—VOLATILE CONTAMINANTS
Compound
Carbon disulrkje
1 2-Dichloroethane
1 1-Dfchloroelhylene . . .
Methylene chloride
Methyl othly ketone « _
Pyridine _.
1112 .T»tTachlwfhap»
112 2-Tetrachloroethane
Te&aGWoroettiyfpnfl,,,.,
Toluene
1 1 V-TricMoroethane. ,..,. ,,.,„ ,
1,1,2-Trichtoroemane — — ..
Vinyl chloride -.
CASNO
107-13
71-49
75-15
108-9O
67-66
107-08i
75-35-
78-83-
75-09-
78-93-
110-88-
630-20-
73-34-
127-18-
108-88-
71-55-
79-00-
79-01
75-01
TABLE 2.—SUITABLE ROTARY AGITATION APPARATUS '
Company
Location
Alexandria Virginia {709)5^fl-5flfl9, '.
Whitmore Laka. Michigan (313) 449-4118
Santurce Puerto Rice (809> 752-4004 :
Model
4-vessel deviosi
10-vessel device.
6-vesset devicet
16-vesset device.
6-vessel device:1
' Any device which rotates the extraction vessel in an end-over-end fashion at 30 ±2 rpm is acceptable.
1 Although this device is suitable, it is not commercially made It may also require retrofitting to accommodate ZHE devices.
TABLE 3.—SUITABLE ZERO-HEADSPACE EXTRACTOR VESSELS
Company
Location
Alexandria. Virginia, (703) 549-5999
Bedford Massacliusulls, (800) 225-3384
Model No.
3740-ZH8
SD1P581C5
TABLE 4.—SUITABLE FILTER HOLDERS '
Company
Micio FHtratfon Syitofns.««...«.....« „...,.,... , «
Location
Reasanton California |MO> 862-7711 «_
Dublin, California. (415) 828-6010
Model
425910 -....
410400
302400 -
XX1004700 -....
Size
(millima
> Any dovide capable ot separating the BqukJ fnxn the solid phase of the waste is suitable, providing that it is chemically compatible with the waste and the constituents to be :
Plastic device* (not fated above! may be used whan only Inorganic contaminants are of concern.
TABLE 5.—SUITABLE FILTER MEDIA
Company
Location
Clifton New Jersey (201) 773-5800
Model
GFF
Pore size
0.
1 Nominal pore siz*.
BILLING CODE 85M-SO-W
-------
Federal Bagjgter / VoL 51, No. 9 / Taesday. January 14, 1986 / Proposed Ruies
Liquid Inlet/Outlet Valve
•F ilcer-
Waste/Extraction Fluid
f
Piston
Top
Flange
Body
VI TON
0-rings
Bottom
Flange
Pressurizing Gas Inlet/Outlet Valve
Figure 3: Zero-Headspace Extraction Vessel
BIU.IMO crmn Raw-sn-c
-------
Federal Register-/ Vol. 51, No; 9 /Tuesday, January 14,1986 / Proposed Rules 175
Motor
(30 i 2 rpm)
Extraction Vessel Holder
Figure 2t Rotary Agitation
-------
1760
Federal Ragister / VoL 51. No. a / Tuesday. Januaiy 14. 1986 / Proposed Rules
Subpart E— Manifest System,
Recordkeeping, and Reporting
3. fa 1 28473, by revising paragraph
(b)(3) and adding paragraph (b)f 10} to
read as follows:
§264.73 Operating record.
(3) Records and results of waste
analyses performed as specified in
§ § 264.13, 264.17, 264^14, and 284341,
and § § 28S.l(e) and 288.8 -of this chapter.
*****
(10) Records of the quantities [and
date of placement) for each shipment of
hazardous waste placed in land disposal
units under an extension to the effective
date of any land disposal restriction
granted pursuant to § 288.4 of tins
chapter or -a petition pursuant to i 288.5
of this chapter and a copy of the
extension or petition approval notice, as
appropriate:
PART 265— INTERIM STATUS
STANDARDS FOR OWNERS AND
OPERATORS OF HAZARDOUS WASTE
TREATMENT, STORAGE, AND
DISPOSAL FAdUTHES
V. In Part 265: •
1. The authority citation for Part 265 is
revised to read as follows:
Authority: Sees. 1000, 20Q2(a). 3604. and
3005 of the Solid Waste Disposal Act, an
amended (42 U.S.C. 6905, 6908, 6912faL 6924.
and 6925).
Subpart B— General Facility Standards
2. In § 285.13, paragraphs (a)(l) and
(b)(6J are revised and paragraph (b)(7) is
added to read as follows:
§265.13 General waste analysts.
(a)(l) Before an owner or operator
treats, sturdy, or disposes of any
hazardous waste, he must obtain a
detailed chemical and physical analysis
of a representative sample of the waste.
At a minimum, this analysis must
contain all the information which must
be known to treat store, or dispose of
the waste in accordance urifh the
requirements of this part and Part 268 of
this chapter.
*****
(b)* ' *
(6) Where applicable, the methods
which will be used to meet the
additional waste analysis requirements
for specific waste management methods
as specified in §§ 265.193, 265.225,
265.252, 265.273, 285.314, 265 .345, 265.375,
and 265.402 and { 268.6 of this chapter.
(7) For surface impoundments subject
to the exemption from land disposal
restrictions under § 268.1(e) of this
chapter, the procedures and schedule
for:
(i) The sampling of impoundment
contents;
(ii) The analysis of test data; and,
(iii) The annual removal of residue
-which does not meet the standards of
Part 268 Subpart D of this chapter.
Subpart E— Manifest System,
Recordkeeping, and Reporting
3. In § 285.73, paragraph (b)(3) is
revised and paragraph (b){8) is added to
read as follows: . •
§265.73
(b) * * *
(3) Records and results of waste
analysis and trial tests performed aa
specified in S3 265.13, 285.193, 285.225.
265.252, 265.273, 285.314, 265.341, 265.375,
and 265.402 and « 268.1(e} and 268.6 of
this chapter.
**»-**
(8) Records of the quantities (and date
of placement) lor each shipment of
hazardous waste placed ia land disposal
units under an extension to the effective
date of any land disposal restriction
granted pursuant to § 268.4 of this
chapter, or a petition pursuant to 5 268.5
of this chapter, and a copy of the
extension or petition approval notice as
appropriate.
PART 268— LAND DISPOSAL
RESTRICTIONS
VI. In Part 268, proposed in the
Federal Register of May 31, 1985 (50 FR
23255):
1. The authority citation for proposed
Part 268 is revised to read as follows:
Authority: Sees. 1006, 2002(a), 3001, and
3004 of the Solid Waste Disposal Act, as
amended by the Resource Conservation and
Recovery Act of 1976, aa amended by the
Hazardous and Solid Waste Amendments of
1984 (42 U.S.C. 6905. 6912(aj. 6921, and 6924).
2. By adding Subpart A to proposed
Part 268 to read as follows:
Subpart A— GoMrai
Sec.
268.1 Purpose, scope, and applicability.
268.2 Definitions applicable to this part
268.3 Dilution prohibited as a substitute for
treatment.
268.4 Procedures £or -extensions to an
effective date.
268.5 Petitions to allow land disposal of a
waste prohibited under Subpart C of Part
268.
268.6 Waste analysis.
268.9 Incorporations by reference.
Subpart Ar-Ganeral
§268.1 Purpose, scope and appttcaWfttv.
(a) This part identifies hazardous
wastes that are restricted from land
disposal and those limited
circumstances under which an
otherwise prohibited waste may
continue to be land disposed.
(b) Except as specifically provided
otherwise in this part or Part 261 of this
chapter, the requirements of this part
apply to persons who generate or
transport hazardous waste and owners
and operators of hazardous waste
treatment, storage, aad disposal
facilities.
(c) The requirements of Subparts A, C,
D and E of this part do not apply to the
disposal of hazardous waste by
underground injection.
(d) The requirements of this part apply
to a person who generate*, transports,
treats, stores, or disposes of hazardous
waste in a State which Js authorized
under Sabpart A or B of Part 271 of this
chapter if the State has not been
authorized to carry out the requirements
and prohibitions applicable to the
generation, transport, treatment, storage,
or disposal of hazardous waste which
are imposed pursuant to the Hazardous
and Solid Waste Amendments of 1984.
The requirements and prohibitions that
are applicable antil a State receives
authorization to carry them out include
all Federal program requirements
identified in § 271.1Q) of this chapter.
(e) The requirements of this part do
not apply, to persons placing hazardous
wastes in a surface impoundment
provided that:
(1) Treatment of such wastes occurs in
the impoundment.
(2) The contents of the impoundment
must be analyzed, through use of the
test methods described in SW-846 aad
the residues of «wch treatment (including
any liquid waste) that do not meet the
treatment standards promulgated under
Subpart D of this part, or are not
delisted under $ 260.22 of this chapter,
must be removed at least annually and
may not be placed in a surface
impoundment for subsequent treatment.
The procedures and schedule for (i) the
sampling of impoundment contents, (ii)
the analysis of test data, and (iii) the
annual removal of residue which does
not meet Subpart O treatment standards
must be specified in the facility's waste
analysis plan as required under
§§ 264.13 or 265.13 of this chapter.
(3) The impoundment meets the desig:
requirements of § 264221{c) or
§ 265.221(a) of this chapter, unless:
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1762
Federal Register / Vol. 51. No. 9 / Tuesday. J
1986 / Proposed Rules
designated facility prior to the first
shipment of waste which is the subject
of the extension. The owner or opreator
of the facility shall retain a copy of the
notice during the period of the extension
and for at least 3 years after the
extension expires.
(g) The successful applicant must
immediately notify the Administrator as
soon as he has knowledge of any
changes in the conditions certified to in
the application.
(h) The successful applicant must
submit written progress reports at
intervals designated by the
Administrator. Such reports must
describe the overall progress made
toward constructing or otherwise
providing alternative treatment,
recovery or disposal capacity; must
identify any event which may cause or
has caused a delay in the development
of the capacity; and must summarize the
steps taken to mitigate the delay. The
Administrator can revoke the extension
at any time if the applicant does not
demonstrate a good-faith effort to meet
the schedule for completion, if the
Agency denies or revokes any required
permit, if conditions certified in the
application change, or for any violation
of this part.
(i) Whenever the Administrator
establishes an extension to an effective
date under this section, during the
period for which such extension is in
effect:
(1) The storage restrictions under
§ 268.50{d)(l) do not apply, and
(2) Such hazardous waste may be
disposed of in a landfill or surface
impoundment, only if:
(i) The landfill, if in interim status,
meets the requirements of Subpart F of
Part 265 and § 265.301 (a) through (e) of
this chapter.
(ii) The landfill, if permitted, meets the
requirements of Subpart F of Part 264
and § 264.301 (c) through (ej of this
chapter.
(iii) The surface impoundment, if in
interim status, meets the requirements of
Subpart F of Part 265 and § 265.221 (a)
through (e) of this chapter; or
(iv) The surface impoundment, if
permitted, meets the requirements of
Subpart F of Part 264 and § 264.221 (c)
through (e) of this chapter.
§ 268.5 Petitions to allow land disposal of
a waste prohibited under Subpart C of Part
268.
(a) Any person seeking a variance
From a prohibition under Subpart C of
this part for the disposal of a restricted
hazardous waste in a particular unit or
units must submit a petition to the :
Administrator demonstrating that any
hazardous constituents of the waste are
at levels that ensure, to a reasonable
degree of certainty, that there will be no
migration of any such hazardous
constituents of the waste* from the area
of effective control into the air, ground
water, surface water, or soil in
concentrations that exceed the
applicable screening level, or that result
in adverse effects upon the environment.
(1) The Administrator will use the
following criteria for determining
whether the established screening levels
may be exceeded for any threshold
constituents:
(i) Exposure criteria:
(A) Other potential or actual sources
of exposure to the same or similar
constituents.
(B) The level and type of uncertainty
inherent in the models used to predict
potential exposure to the surrounding
population.
(C) The nature of the potentially
exposed population.
{ii) Toxicological criteria:
(A) The slope or slopes of dose
response curves for the health effects
attributable to a threshold constituent.
(B) The frequency and magnitude of
potential exposure to a threshold
constituent.
(2) The Administrator will use the
following criteria for determining a
health effects level for any non-
threshold constituents:
(i) Exposure criteria:
(A) Other potential or actual sources
of exposure to the same or similar
constituents.
(B) The level and type of uncertainty
inherent in the models used to predict
potential exposure to the surrounding
population.
(C) The potential current and future
risk to individuals from the activities of
the disposal unit.
(D) The size and nature of the
potentially exposed population.
(ii} Toxicological criteria: the level
and type of uncertainty inherent in the
data used to estimate health risks.
(b) The demonstration referred to in
paragraph (a) of this section must
include an analysis of the total number
of people that could potentially be
exposed to any hazardous constituent of
the specified waste for as long as the
specified waste remains hazardous.
(c) The demonstration referred to in
paragraph (a) of this section must
include assurances that land disposal of
the specified waste will not cause
adverse effects on any aquatic biota,
wildlife, vegetation, protected lands, or
other areas of potential ecological or
economic significance.
(d) The demonstration referred to in
paragraphs (a), (b), and (c) of this
section may include the following
components:
(1) An identification of the specific
waste and the specific unit for which the
demonstration will be made.
(2) A waste analysis, using methods
described in SW-848, where
appropriate, or equivalent methods
approved by the Administrator in
accordance with § 260.21 of this chapter,
to describe fully the chemical and
physical characteristics of the subject
waste, including the waste's toxicity, -
mobility, persistence, and propensity to
bioaccumulate.
(3) An evaluation of the performance
of the engineered components of the
disposal unit.
(4) A comprehensive characterization
of the disposal unit site and area of
effective control, including an analysis
of background air, soil, and water
quality.
(5) Predictions of the ultimate fate of
hazardous constituents in the air, soil,
surface water, and ground water, at the
point or points of potential human and
environmental exposure.
(e) The demonstration referred to in
paragraphs (a), (b), and (c) of this
section must meet the following criteria:
(1) All waste and environmental
sampling or test data must be accurate,
and reproducible.
(2) All sampling, testing, and
estimation techniques for chemical and
physical properties of the waste and all
environmental parameters must have
been approved by the Administrator.
(3) Simulation models may need to be
calibrated for the specific waste and site
conditions, and verified for accuracy by
comparison with actual measurements.
(4) A quality assurance and quality
control plan that addresses all aspects
of the demonstration must be approved
by the Administrator.
(5) An analysis may need to be
performed to identify and quantify any
aspects of the demonstration that
contribute significantly to uncertainty.
This analysis must include an
evaluation of the consequences of
predictable future events, including, but
not limited to earthquakes, floods,
severe storm events, droughts, or other
natural phenomena.
(f) Each petition must be submitted to
the Administrator by certified mail.
(g) Each petition must include the
following statement signed by the
petitioner or an authorized
representative:
I certify under penalty of law that I have
personally examined and am familiar with
th6 information submitted in this petition and
all attached documents, and that, based on
my inquiry of those individuals immediately
-------
(i) Exempted ponvant to £284.221 f d)
or (e) of this chapter, or § 265^21 (c) or
(d) of this chapter, or
(ii) Upon application of the owner or
operator prior to Novembers, 1986, the
Administrator has granted a waiver of
the requirements on the basis that the •
surface impoundment:
(A) Has at least one liner, for which
there is no evidence that such liner is
leaking;
(B) Is located more than one-quarter
mile from an underground source of
drinking water; and
(C) Is in compliance with the generally
applicable ground water monitoring
requirements for facilities with permits:
or
(iii) Upon application of the owner or
operator prior to November 8, 1986, the
Administrator has granted a
modification of the requirements on the
basis of a demonstration that the
surface impoundment is located,
designed, and operated so as to assure
that there will be no migration of any
hazardous constituent into ground water •
or surface water at any future time.
(f) The requirements of this part do
not apply to:
(1) Persons who have been granted a
variance from a prohibition pursuant to •
§ 268.5, with respect to those wastes and
units covered by the variance; or,
(2) any land disposal of contaminated
soil or debris resulting from a response
action taken under section 102 or 106 of
the Comprehensive Environmental
Response, Compensation, and Liability
Act of 1980 or a corrective action
required under Part 284 or 265 of this
chapter until November 8, 1988.
(g) A generator or an owner or
operator of a facility otherwise
regulated by this part must comply with
all applicable' requirements of this
chapter.
/ VQ[: Si, Mfe g- / Toeaday. Jantmry 14, 1386- / ftopofied Rules
§26&2 Definitions appticabfe to mte part
(a) When used in this part the
following terms have the meanings given
below:
"Area of effective control" means an
area where perpetaatnatrictions exist
on the use of any air or water resource*
in a manner that would not be
protective of human health and die
environment If this area extends
beyond the waste management area, as
defined at § 264.95(b) of this chapter,
perpetual restrictions on the use of any
air or water resources must be
established by an act of the local or
State legislature.
"Hazardous constitutent or
constituents" means those constituents
listed in Appendix VIII to Part 261 of
this chapter.
"Land disposal" means placement in-
or on the land and includes, but is not
limited to, placement hi a landfill,
surface impoundment, waste pile,
infection well, land treatment facility,
salt dome formation, salt bed formation,
underground mine or cave, concrete
vault or bunker intended for disposal
purposes and placement in or on the
land by means of open detonation. The
term "land disposal" does not
encompass ocean disposal.
(b) AH other terms have the meanings
given under §§ 260.10, 261.2, 261.3. or
270.2 of this chapter.
268.3 Ofcition prohibited a* a Mibstttut*
for treatment
No generator or owner or operator of
a treatment storage, or disposal facility
shall in any way attempt to dilute a
waste as a substitute for adequate
treatment to achieve compliance with
Subpart D of this part
§ 268.4 Procedures for extension* to an
effectiva-dafft.
(a) Any person who generates, treats,
stores, or disposes of a hazardous waste
restricted (or proposed to be restricted}
from land disposal pursuant to Subpart
C of this part may submit an application
to the Administrator for an extension to
the effective date of any applicable
restriction established under §§ 26&30,
268.31; or 268.40. The applicant must
demonstrate the following:
(1) He has entered into a contract to
construct or otherwise provide
alternative treatment recovery
(recycling), or disposal capacity that
protects human health and the
environment. The contract must contain
a penalty for cancellation that in the
Agency's judgment is sufficient to
discourage cancellation by the
applicant
(2) Due to circumstances beyond the
applicant's control such alternative
capacity cannot reasonably be made
available by the applicant by the '
applicable effective date.
(3) The applicant has made a good-
faith effort to locate and contract with
treatment recovery, or disposal
facilities nationwide to manage his
waste in accordance with { § 268.30 or
268.31.
(4) The capacity being constructed or
otherwise provided by the applicant will
be sufficient to manage all of the waste
that is the subject of the application.
(5) The applicant has prepared and
submitted to the Administrator a
detailed schedule for obtaining required
operating permits and construction or an
outline of how and when alternative
capacity will be provided.
(6) The applicant has arranged for
adequate capactiy to manage his waste
during an extension and has
documented m the application the
location of all sites at which the waste •
will be managed.
(7) Any waste managed in a surface
impoundment or landfill during the
extension period will meet the
requirements of paragraph (i) [2) of this
section.
(b) Any person signing an application |
described under paragraph (a) of this
section shall make the following
certification:
I certify muter penalty of law that I have
personally examined and am familiar with
the information submitted in thi* document
and all attachments and that, based on my
inquiry of those individuals immediately
responsible for obtaining the information. I
believe that the information is true, accurate.
and complete. 1 am aware that there are
significant penalties for submitting false
information, including the possibility of fine
and imprisonment
(cj On the basis of the information
referred to in paragraph (a) of this
section, after notice and opportunity for
comment, and after consultation with
appropriate State agencies in all
affected States, the Administrator may
grant an extension of up to 1 year from
the effective date. The Administrator
may renew this extension for up to 1
additional year upon the request of the
applicant. In no event will an extension
extend beyond 48 months from the
applicable statutory effective date
specified in section 3004(d), (e), or (g) of
the Act (42 U.S.C. 6924(d), (e), or,(g)J.
(d) The length of any extension
authorized in paragraph (c) of this
section will be determined by the
Administrator based on the time
required to construct or obtain the type
of capacity needed by the applicant as
described in the completion schedule
discussed in paragraph (a)(5) of this
section.
(e) The Administrator will provide the
successful applicant with written notice
of the extension. This notice will
describe the manufacturing process that
is the source of the waste subject to the
extension, the volume of such waste, the
duration of. the extension, and the name
and the location of the facility
designated in paragraph (a)(6) of this
section to manage the waste during the
period of the extension. The applicant
must retain a copy of the notice during
the period of the extension and for at
least 3 years after the extension expires.
(f) The applicant must provide a copy
of the notice to the facility designated in
paragraph (a)(6) of this section. The
notice must be provided to the
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1764
acetone* ethyl acetate, ethyl
benzene, ethyl ether, methyl
isobutyl ketone, n-butyl alcohol,
cyclohexanone, and methanol; all
spent solvent mixtures/blends
containing, solely the above spent
non-halogenated solvents; and all
spent solvent mixtures/blends
containing, before'use, one or more
of the above non-halogenated
solvents, and a total of 10 percent or
more (by volume) of one or more of
those solvents listed in FOOl, F002,
F004, and F005; and still bottoms
from the recovery of these spent
solvents and spent solvent
mixtures.
F004—The following spent non-
halogenated solvents: cresols and
cresylic acid and nitrobenzene; all
spent solvent mixtures/blends
containing, before use, a total of 10
percent or more (by volume) of one
or more of the above non-
halogenated solvents or those
solvents listed in F001, F002, and
F005; and still bottoms from the
recovery of these spent solvents
and spent solvent mixtures.
F005—The following spent non-
halogenated solvents: toluene,
methyl ethyl ketone, carbon
disulfide, isobutanol, and pyridine;
all spent solvent mixtures/blends
containing, before use, a total of 10
percent or more (by volume) of one
or more of the above non-
halogenated solvents or those
solvents listed in F001, F002, and
F004; and still bottoms from the
recovery of these spent solvents
and solvent mixtures.
P022—Carbon disulfide
U002—Acetone
U031—n-Butyl alochol
U037—Chlorobenzene
U052—Cresols and cresylic acid
U057—Cyclohexanone
U070—o-Dichlorobenzene
U080—-Methylene chloride
U112—Ethyl acetate
U117—Ethyl ether
U121—Trichlorofluoromethane
U140—Isobutanol
U154—Methanol
U159—Methyl ethyl ketone
UlOl—Methyl isobutyl ketone
U169—Nitrobenzene
U196—Pyridine
U210—Tetrachloroethylene
U211—Carbon tetrachloride
U22(WbIuene
U226—1,1,1-Trichloroethane
U228—Trichloroethylene
U239—Xylerie
§ 268.31 Waste specific prohibitions-
Group II. ;, ' ,' > '
fa) Effective .November 8,1988, the
wastes listed in paragraph (c) of this
section are prohibited from land
disposal, except in an injection well,
unless:
(1) The wastes are treated to meet the
standards of Subpart D of this part, or
(2) The Wastes are subject to a
successful petition under § 268.5, or
(3) An extension has been granted
under | 268.4.
(b) Between November 8,1988, and
November 8,1988, wastes identified in
paragraph (c) of this section may be
disposed of in a landfill or surface
impoundment only if the facility is in
compliance with the minimum
technological requirements of § 268.4
(c) Prohibited are:
(1) The following solvent-containing
wastes (containing less than 1 percent
(by weight) total organic constituents)
and solvent contaminated soils.
F001—The following spent halogenated
solvents used in degreasing:
tetrachloroethylene,
trichloroethylene, methylene
chloride, 1,1.1-trichloroethane,
carbon tetrachloride, and
chlorinated fluorocarbons; all spent
solvent mixtures/blends used in
degreasing containing, before use, a
total of 10 percent or more (by
volume) of one or'more of the above
halogenated solvents or those
solvents listed in F002, F004, and
F005; and still bottoms from the
recovery of these spent solvents
and spent solvent mixtures.
F002—The following spent halogenated
solvents: tetrachloroethylene,
methylene chloride,
trichloroethylene, 1,1,1-
trichloroethane, chlorobenzene,
l,1.2-trichloro-l,2,2-trifluoroethane,
ortho-dichlorobenzene, and
trichlorofluoromethane; ail'spent
solvent mixtures/blends containing,
before use, a total of 10 percent or
more (by volume) of one or more of
the above halogenated solvents or
those solvents listed in FOOl, F004,
and F005; and still bottoms from the
recovery of these spent solvents
and spent solvent mixtures.
F003—The following spent non-
halogenated solvents: xylene,
acetone, ethyl acetate, ethyl
benzene, ethyl ether, methyl
isobutyl ketone, n-butyl alcohol,
cyclohexanone, and methanol; all
spent solvent mixtures/blends
containing solely the above spent
non-halogenated solvents; and all
spent solvent mixtures/blends
containing, before use, one or more
of the above non-halogenated
solvents, and a total of 10 percent or
more (by volume) of one or more-of
those solvents listed in FOOl, F002,
F004, and F005; and still bottoms
from the recovery of these spent
solvents and spent solvent
mixtures.
F004—The following spent non-
halogenated solvents: cresols and
cresylic acid and nitrobenzene; all
spent solvent mixtures/blends
containing, before use, a total of 10
percent or more (by volume) of one
or more of the above non-
halogenated solvents or those
solvents listed in FOOl, F002, and
F005; and still bottoms from the
recovery of these spent solvents
and spent solvent mixtures.
F005—The following spent non-
halogenated solvents: toluene,
methyl ethyl ketone, carbon
disulfide, isobutanol, and pyridine;
all spent solvent mixtures/blends
containing, before use, a total of 10
percent or more (by volume) of one
or more of the above non-
halogenated solvents or those
solvents listed in FOOl, F002, and
F004; and still bottoms from the
recovery of these spent solvents
and spent solvent mixtures.
P022—Carbon disulfide
U002—Acetone
U031—n-Butyl alcohol
U037—Chlorobenzene
U052—Cresols and cresylic acid
U057—Cyclohexanone
U070—o-Dichlorobenzene
U080—Methylene chloride
U112—Ethyl acetate
U117—Ethyl ether
U121—Trichlorofluoromethane
U140—Isobutanol
U154—Methanol
U159—Methyl ethyl ketone
Ul61-r-Methyl isobutyl ketone
U169—Nitrobenzene
U196—Pyridine
U210—Tetrachloroethylene
U211—Carbon tetrachloride
U220—Toluene
U226—1,1,1-Trichloroethane
U228^—Trichloroethylene
U239—Xylene
(2} The following dioxion-contaming
wastes:
F020—Wastes (except wastewater and
spent carbon from hydrogen
chloride, purification} from the
production and manufacturing use
(as a reactant, chemical
intermediate, or component in a
formulating process) of tri-, or
tetrachlorophenol or of
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FiB*»ar
: 1«. No??/ Ttteaday^ January. 14,.
Proposed Rules
1783!
"opooeibJB for obtaiafag fte informatioa, I
believe that the subaittedinfonnation i» (TUB,
accurate, and complete. I «m aw«re that there
are significant penalties for submitting, false
information, including the possibility of fine
and imprisonment.
(h) After receiving a petition, the
Administrator may request any
additional information that may
reasonably be required to evaluate the '
demonstration.
(i) If approved, the petition will apply
to land disposal of the specific restricted
waste at the individual disposal unit
described in the demonstration and will
not apply to any other restricted waste
at that disposal unit.
0) The Administrator shall give public
notice of the intent to approve or deny a
petition and provide an opportunity for
public comment. The Administrator
shall give public notice of the fatal
decision on a petition in the Federal
Register.
(k)(l) The Administrator will provide
written notice to the petitioner upon
approval or denial of a petition. If
approval is given, the notice will
identify the land disposal unit, the
wastes that may be disposed therein,
the volume limit, and the duration of the
approval.
(2) The petitioner shall retain the
notice for the term of the approval as
defined by paragraph (1) of this section.
(1) The term of an approved petition
shall be no longer than the term of the
RCRA permit if the disposal unit is
operating under a RCRA permit, or up to
a maximum of 10 years from the date of
the notice provided under paragraph
(k)(l) of this section if the unit is
operating under interim status. In either
case, the term of the approved petition
shall expire upon the termination-or
denial of a RCRA permit or npon the
termination of interim status or when
pie volume limit specified in the petition
is reached.
§268.8 Waste analysis.
(a) The owner or operator of any land
disposal facility "^"frfforg any waste
subject to restrictions under this part,
must have records of either the
treatment certification specified in
paragraph (b) of this section or of
sufficient waste analysis through testing
of the waste for the constituents fisted in
Table CCWE in 5 268.42 to determine
whether the wastes are in compliance
with the applicable treatment standards
specified in Subpart D of this part. The
waste most be tested using the methods
described in SW-3M or equivalent
methods approved by the Administrator
in accordance with §5 280.20 and 260.21
of this chapter.
(b) Where the applicable treatment
standard for a waste is treatment by a
specific technology [i.e., § 288.41(a)), the
owner or operator of the treatment
facility must submit a certification to the
land disposal facility stating that the
waste has been treated using the
specified technology. The certification is
subject to the- following requirements:
(I) The certification must be signed by
the treater or his authorized
representative and must state the
following: s _
I certify under penalty of law that I have
personally examined and am familiar with
the treatment technology and operation of the
treatment process used to support this
certification and that, based on my inquiry of
those individuals immediately responsible for
obtaining this information, I believe that the
treatment process has been operated and
maintained properly so as to achieve the
treatment siandards-of the specified
^technology without dilution of the prohibited
'waste. I am aware that there are aignifir.ant
penalties for submitting a false certification
including the possibility of fine and
imprisonment
(2) The certification must be sent to
the land disposal facility before the,
treated waste (including treatment
residues) is shipped by the treater and
must be kept on site for 3 years after the
waste is placed in a land disposal unit
at the facility.
§268.9 Incorporations by rotarenc*.
The following material is incorporated
by reference and is available for
inspection at the Office of the Federal
Register Information Center, Rm. 8301,
1100 L St., NW., Washington, DC 20408.
These incorporations by reference were
approved by the Director of the Office of
the Federal Register. The material is
incorporated as it exists on the date of
approval and a notice of any change in
the material win be published in the
(a) "Test Methods for Evaluating Solid
Waste, Physical/Chemical Methods,"
EPA Publication SW-846 (First Edition,
1980; as updated by Revision A (August
19SOJ, Bfjary 198T), and C (February
1982) er Second Edition, 1982). The first
edition of SW-846 is no longer in print.
Revisions A and B are available from
NTIS. 5285 Port Royal Road, Springfield,
Virginia 221«1. The second edition of
SW-848 includes material from the first
edition and Revisions A, B, and C in a
reorganized format. It is available from
the Superintendent of Documents, U.S.
Government Printing Office,
Washington, D.C. 20402 (202-783-3238),
on a subscription basis, arid future
updates will automatically be mailed to
the subscriber. The material is cited in
the following sections of Part 288:
§§ 288.1(e)t2),.288.otc)(2). 288.6(a), and
288.42(a).
{b) [Reserved.]
3. By adding Subpart C to proposed
Part 268 to read as follows:
Subpart C—Prohibitions on Land Disposal
Sec.
268.30 Waste specific prohibitions—Group
288.31 Waste specific prohibitions—Group
n.
Subpart C—Prohibition* on Land
Disposal
§ 268.30 Waste specific prohibitions-
Group I.
(a) Effective November 8,1986, the
wastes listed in paragraph (b) of this
section are prohibited from land
disposal, except in an injection well
unless:
(1) The wastes are treated to meet the
standards of Subpart D of this part, or
(2) The wastes are subject to a
successful petition under $ 268.5, or
(3) An extension has been granted
under § 268.4.
(b) Prohibited are the following
solvent containing wastes containing
greater that 1 percent (by weight) total
organic constituents, except for solvent
contaminated soils:
F001—The following spent halogenated
solvents used in decreasing:
tetrachioroethyiene,
trichloroethyl«ne, methyiene
chloride, 1,1,1-trichIoroethane,
• carbon tetrachloride, and
chlorinated fruorocarbons; all spent
solvent mixtures/blends used in
degreasing containing, before use, a
total of 10 percent or more (by
volume) of one or more of the above
halogenated solvents or those
solvents listed in F002. F004, and
F005; and still bottoms from the
recovery of these spent solvents
and spent solvent mixtures.
F002—The following spent halogenated
solvents: tetrachioroethyiene,
methyiene chloride. .
trichloroethylene, 1.1,1-
trichloroethane, chlorobenzene,
l,l,2-trichloro-l,2,2-trifluoroethane.
ortho-dichlorobenzene, and
trichlorofluoromethane; all spent
solvent mixtures/blends containing,
before use, a total of 10 percent or
more (by volume) of one or more of
the above halogenated solvents or
those solvents listed in FOOl, F004,
and F005; and still bottoms from the
recovery of these spent solvents
and spent solvent mixtures.
F003—The following spent non-
halogenated solvents: xylene,
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1766
Federal Ragister / Vol. 51, No. 9 / Tuesday, January 14, 1986 / Proposed Rules
§ 268.43 Treatment standards expressed
as waste concentrations. [Reserved]
5. By adding Subpart E consisting at
this time of § 268.50 to proposed Part 268
to read as follows:
Subpart E—Prohibitions on Storage
§ 268.50 Prohibitions on storage of
restricted wastes.
(a) A hazardous waste prohibited
from land disposal under Subpart C of
this part may not be stored in tanks or
containers after the prohibition effective
date unless:
(1) The owner or operator of a
hazardous waste treatment, storage, or
disposal facility stores such waste for 90
days or less; or
(2) A transporter stores manifested
shipments of such waste in containers at
a transfer facility for 10 days or less; or,
(3) Such waste is accumulated on site
by the generator and does not exceed
the applicable time limitations set forth
in § 262.34 of this chapter.
(b) The prohibition in paragraph (a) of
this section does not apply to the
conditions of an approved petition under
§ 268.5 or an approved case-by-case
extension under § 268.4.
(c) The prohibition in paragraph (a) of
this section does not apply to hazardous
wastes that meet the treatment
standards specified under Subpart D of
this part.
PART 270—EPA-ADMINISTERED
PERMIT PROGRAMS: THE
HAZARDOUS WASTE PERMIT
PROGRAM
VII. In Part 270:
1. The authority citation of Part 270 is
revised to read as follows:
Authority: Sees. 1006, 2002. 3005, 3007, and
7004 of the Solid Waste Disposal Act, as
amended by the Resource Conservation and
Recovery Act of 1976. as amended by the
Hazardous and Solid Waste Amendments of
1984 (42 U.S.C. 6905, 6912, 6925,6927, and
6974).
Subpart B—Permit Application
2. In § 270.14, paragraph (b}{21) is
added to read as follows:
§ 270.14 Contents of Part B: General
requirements.
.
(21) For land disposal facilities, if a
case-by-case extension has been
approved under § 268.4 or a petition has
been approved under § 268.5, a copy of
the notice of approval for the extension
or petition, whichever is applicable
Subpart C—Permit Conditions
3. In § 270.32, paragraph (b)(l) is
revised to read as follows:
§270.32 Establishing permit conditions.
*****
(b)(l) Each RCRA permit shall include
permit conditions necessary to achieve
compliance with the Act and
regulations, including each of the
applicable requirements specified in
Parts 264 and 268 through 268 of this
chapter. In satisfying this provision, the
Administrator may incorporate
applicable requirements of Part 264 and
268 through 268 of this chapter directly
into the permit or establish other permit
conditions that are based on these parts.
PART 271—REQUIREMENTS FOR
AUTHORIZATION OF STATE
HAZARDOUS WASTE PROGRAMS
VIII. In Part 271:
1. The authority citation for Part 271 is
revised to read as follows:
Authority: Sees. 1006,2002(a) and 3006 of
the Solid Waste Disposal Act, as amended by
the Resource Conservation and Recovery
Act, as amended by the Hazardous and Solid
Waste Amendments of 1984 {42 U.S.C. 6901 et
seq.)
Subpart A—Requirements for Final
Authorization
2. fa § 271.10). Table 1 is amended by
inserting the following entry in
chronological order by date of
publication in the Federal Register to
read as follows:
§ 271.1 Purposa and scope.
*****
(]')**•
TABLE 1—REGULATION IMPLEMENTING THE
HAZARDOUS AND SOLID WASTE AMEND-
MENTS OF 1984
Date
Title of regulation
[Date of publication at the Land disposal restrictions.
final rule in the F*dml
Register}.
3. In § 271.10 paragraph (i) is added to
read as follows:
§ 271.10 Requirements for generators of
hazardous wastes.
(i) The State must require all >
generators of hazardous wastes
restricted from land disposal under
Subpart C of Part 268 of this chapter to
comply with requirements that are
equivalent to the requirements for
persons filing petitions under § 268.5 of
this chapter.
4. In § 271.12 the introductory text is
revised and paragraph (k) is adde'd to
read as follows:
§ 271.12 Requirements for hazardous
waste management facilities.
The State shall have standards for
hazardous waste management facilities
which are equivalent to Parts 264 and
268 and § 288.5 of this chapter. These
standards shall include:
*****
(k) Requirements for petitions
demonstrating land disposal to be
protective of human health and the
environment, to the extent they are
included in § 26&5 of this chapter.
[FR Doc. 86-618 Filed l-13-«6; 9:30 am]
BILLING CODE «5«0-SO-«I
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Federal Register / Vet. 51, Ne,-9 /- Tuesday,- January 14, 1986 / Pttmosed Rules
1785
intermediates used to produce their Sec- for Solid Waste and Emeroennv
pesticide derivatives. fThis listing 268.42 Treatment levels expressed as Ks^wffis^KSSS
does not include wastes from th7 ,„ 2™**?**, in waste extract. Sove to woi'ftTaUematKre
nrndnr-Hnn r.f kova^kin.nnun 268.43 Treatment standards expressed as approve me use oi me alternative
frnm v £1 he*a?hloroPhene waste concentrations. [Reserved] treatment method if he finds that the
from highly purified 2.4.5- ' alternative treatment method provides a
nno tn°7or°Pheno1-) Subpart D—Treatment Standards level of performance equivalent to that
F021—Wastes (except wastewater and AoDiicabiiih, of treatment achieved by methods specified in
Err*""/'0? h^r°8eS, Sa?ds "P "* 6 tme0t Paragraph (a) of this section. Any
ScrioroSricturirSusefas . (a) Prior to land disposal any waste ^^^^^^ ™*
, a reactant, chemical intermediate^ %^££^g£S%g? SSSL'SSST "*
ySffSSS£&SSSS or of «^-".Zff ffi±TL Administrator for Solid Waste and
ta^dJatelSKrodSite technology °r treated using an Emergency Response deems
SSSSea equivalent treatment method approved appropriate. The person to whom such
onoo «r . / by the Administrator or under the certification is issued must comply with
F022—Wastes (except wastewater and procedures set forth hi § 268.41(b).. all limitations contained in such
spent carbon from hydrogen unless th& hazardous constituents in an determination.
chloride purification) from the extract of the waste or in the waste are .„.„ T
manufacturing use (as a reactant. iess than ti,e concentration levels § 268'42 Treatmwrt '•»•'« expressed as
chemical intermediate, or indicated in § 268.42 or § 268 43, concentrations iir waste extract
component in a formulating- respectively. ' ' ' Using the test methods described in '
process) of tetra-, penta-. or (b) For land disposal of a waste listed SW-846 or equivalent methods
hexachlorobenzenes under alkaline in Subpart C of this part but not approved by the Administrator under
conditions. specifically identified in § 268.41, the the procedures set forth in § § 260.20 and
F023—Wastes (except wastewater and concentrations of hazardous 260.21 of this chapter, the extract from a
spent carbon from hydrogen constituents in the waste extract must representative sample of a waste
chloride purification) from the,,. not equal or exceed fee value given for identified in Subpart C of this part, or
production of materials on • any hazardous constituent listed in from the residue of treatment of such a
equipment previously used for the Table CCWE in § 268.42(a). If none of waste, must not contain any of the
production or manufacturing use (as the concentrations of hazardous constituents listed in. Table CCWE at a
a reactant, chemical intermediate, constituents in the waste extract equal concentration greater than the
or component in a formulating or exceed the specified concentrations respective value given in that table
process) of tri-. and listed in Table CCWE in § 268.42(a). the Where the waste contains less than 0.5
tetrachlorophenols. (This listing ' waste may be land disposed without percent filterable solids, the waste itself,
does not include wastes from further treatment. If the concentration of after filtering, is considered to be the
equipment used only for the any hazardous constituent in the waste extract for the purposes of this section.
production or use of extract equals or exceeds a level
hexachlorophene made from highly indicated in Table CGWE in § 268.42(a) TABLE CCWE-CONSTITUENT CONCENTRATION
purified 2.4.5-tnchlorophenol.) for that constituent, the waste must -' IN WASTE EXTRACT
F026—Wastes (except wasfewater and undergo treatment to bring the level
spent carbon from hydrogen below the applicable concentration level Hazardous constituent . concentration
chloride purification) from the before being land disposed. "nmg ' .
z^SssfcZte*. ii^.Ks^r^8^^- *^====^^^ s *
manufacturing use (as a reactant. as a specified technology g£2S£s o?
chemical intermediate, or . («) The followmg was es must be cS^e^ZZZZZZIZZZ: u
component in a formulation *"?ted usm*the identified technology cresois ., *0
process) of tetra-. penta-, or or technol°g'es. or an equivalent method §*££* J»
hexachiorobenzene under aikaime SpJ^t^^te# f A ^bire:::::::::::::::::::::::::::::: II
conditions Administrator for Solid Waste and Ethyl ether 2.0
n«n» «7 !T' j , e , Emergency Response: HXCDO-AII HexactnorodibanzcHMtodns 001 (iPPb)
F027-Discarded unused formulations [Was|es a^d designated treatment 2SLT H~*ta"«""»*»" a*» <"<*»
containing tn-, terra, or technologies will be specified in future Mernar^.ZIZ^ i.o
pentachlorophenol, or compounds actions! Methyiene chloride 1.2
?Thtl?J- °mr,the9e ch?or?P.henols- M A Pers°n ™y ^bmit an $% SLSS^JiZZZZZi: II
(This hsting does not include application to the Assistant Nitrooenzene™. 0.09
formulations containing - AHministratnr for SnliH Waatp anrl PeCOD—All Pentachlorodibenzb-p-dioxins 001 (tppb)
hexachloronhpnp «ivntriP^i7pH frnm Administrator tor &Oim Waste and PeCDF-AIIPentachlorodibenzofurans 001 ;ippb)
nexacmpropnene synthesized trom Emergency Response demonstrating that Pentachlorophenol 1.0
prepurified 2.4,5-trichlorophenol as an alternative treatment method can K*"-r; °'7
the sole component.) achieve a levpl nf nprfnrmanpp TCOD-AD Tetrachlorod^nzo-p^oxms 001 (tppb)
r ' acnieve a level oi periormance TCDF—AII Tetrachiorodibenzoturans 001 (ippw
4. By adding Subpart D to proposed equivalent to that achieved by methods Tetrachioroethyiene : 0.01 s
Part 268 to read as follows: specified in paragraph (a) of this section. asAeretrachiorophenoi 2.0
Subnart D—Troatmnnt Qtanri.rri. The applicant must show that his I.I.ITrlS'iwoei^neZZZZIZZ;"""" 2^0
subpart D-Treatment Standards treatment me.thod will not present an 1.2.2-Triohioro- i.2,2.tyri«uoroethane 2.0
Sec- - unreasonable risk of injury to health or ^S^i^IIIi:i:::i:i. &
268.40 Applicability of trea'tment standards. the environment. On the basis of such 2A5 Tricniorophenoi s.o
268.41 Treatment standards expressed as a information and any other available 2.4£Trichiorophenoi : 0.04
specified technology. ' . information, the Assistant Administrator I '
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&EPA
United States
Environmental Protection
Agency WH 552
Washington, DC 20460
Official Business
Penalty for Private Use
S300
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