[Federal Register Volume 65, Number 118 (Monday, June 19, 2000)]
[Proposed Rules]
[Pages 37932-37956]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-15392]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 268

[FRL-6718-8]
RIN 2050-AE53


Land Disposal Restrictions: Advance Notice of Proposed Rulemaking

AGENCY: Environmental Protection Agency.

ACTION: Advance notice of proposed rulemaking.

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SUMMARY: The Environmental Protection Agency (EPA) is giving advance 
notice of issues and potential directions we are considering for 
improving the Land Disposal Restrictions (LDR) program for treating 
hazardous waste under the Resource Conservation and Recovery Act 
(RCRA). These issues and directions arise from a number of internal and 
external sources, including the participants at two LDR roundtable 
meetings. We are requesting comments on all of these issues, 
directions, and options. In some cases we are requesting additional 
data that will allow us to better evaluate possible changes to the LDR 
regulations.

DATES: To make sure we consider your comments we must receive them by 
September 18, 2000.

ADDRESSES: If you wish to comment on this advanced notice of proposed 
rulemaking (ANPRM), you must send an original and two copies of the 
comments referencing Docket Number F-2000-LRRP-FFFFF to: RCRA Docket 
Information Center, Office of Solid Waste (5305G), U.S. Environmental 
Protection Agency Headquarters (EPA HQ), Ariel Rios Building, 1200 
Pennsylvania Avenue, N.W., Washington, DC 20460, or (2) if using 
special delivery, such as overnight express service. Hand deliveries of 
comments should be made to the Arlington, VA address listed below. You 
may also submit comments electronically by sending electronic mail 
through the Internet to: [email protected]. You should

[[Page 37933]]

identify comments in electronic format with the docket number F-2000-
LRRP-FFFFF. You must submit all electronic comments as an ASCII (text) 
file, avoiding the use of special characters or any type of encryption. 
If you do not submit comments electronically, EPA is asking prospective 
commenters to voluntarily submit one additional copy of their comments 
on labeled personal computer diskettes in ASCII (text) format or a word 
processing format that can be converted to ASCII (text). It is 
essential to specify on the disk label the word processing software and 
version/edition as well as the commenter's name. This will allow EPA to 
convert the comments into one of the word processing formats utilized 
by the Agency. Please use mailing envelopes designed to physically 
protect the submitted diskettes. EPA emphasizes that submission of 
diskettes is not mandatory, nor will it result in any advantage or 
disadvantage to any commenter.
    You should not submit electronically any confidential business 
information (CBI). You must submit an original and two copies of CBI 
under separate cover to: RCRA CBI Document Control Officer, Office of 
Solid Waste (5305W), U.S. Environmental Protection Agency Headquarters 
(EPA HQ), Ariel Rios Building, 1200 Pennsylvania Avenue, NW, 
Washington, DC 20460.
    You may view public comments and supporting materials in the RCRA 
Information Center (RIC), located at Crystal Gateway I, First Floor, 
1235 Jefferson Davis Highway, Arlington, VA. The RIC is open from 9 am 
to 4 pm Monday through Friday, excluding federal holidays. To review 
docket materials, we recommend that you make an appointment by calling 
703-603-9230. You may copy up to 100 pages from any regulatory document 
at no charge. Additional copies cost $ 0.15 per page. (For info on 
accessing paper and/or electronic copies of the document, see the 
Supplementary Information section).

FOR FURTHER INFORMATION CONTACT: For general information, call the RCRA 
Hotline at 1-800-424-9346 or TDD 1-800-553-7672 (hearing impaired). 
Callers within the Washington Metropolitan Area must dial 703-412-9810 
or TDD 703-412-3323 (hearing impaired). The RCRA Hotline is open 
Monday-Friday, 9 am to 6 pm, Eastern Standard Time. For more 
information on specific aspects of this ANPRM, contact Josh Lewis at 
703-308-7877, [email protected], or write him at the Office of Solid 
Waste (5302W), U.S. Environmental Protection Agency Headquarters (EPA 
HQ), Ariel Rios Building, 1200 Pennsylvania Avenue, N.W., Washington, 
DC 20460.

SUPPLEMENTARY INFORMATION: The index and selected supporting materials 
are available on the Internet. Follow these instructions to access the 
information electronically: WWW:http://www.epa.gov/epaoswer/osw/hazwaste.htm#ldr
    The official record for this action will be kept in the paper form. 
Accordingly, EPA will transfer all comments received electronically 
into paper form and place them in the official record which will also 
include all comments submitted directly in writing. The official record 
is the paper record maintained at the RIC listed in the ADDRESSES 
section at the beginning of this document.
    Formal comment responses are not typically required following an 
ANPRM. However, EPA is considering the preparation of a comment 
response document. In the event that EPA prepares such a document, 
EPA's responses will be placed in the official record. EPA will not 
immediately reply to commenters other than to perhaps seek 
clarification of electronic comments that may be garbled in 
transmission or during conversion to paper form, as discussed above.

Glossary of Acronyms

AEA--Atomic Energy Act
ALARA--As Low As Reasonably Achievable
BDAT--Best Demonstrated Available Technology
BRS--Biennial Reporting System
CWA--Clean Water Act
DET--Determination of Equivalent Treatment
DOE--Department of Energy
ETC--Environmental Technology Council
HDPE--High Density Polyethylene
HWIR--Hazardous Waste Identification Rule
HSWA--Hazardous and Solid Waste Amendments
HTMR--High Temperature Metals Recovery
LDR--Land Disposal Restrictions
LDRite--LDR Innovative Technology Evaluation
MSWL--Municipal Solid Waste Leachate
NPDES--National Pollutant Discharge Elimination System
NRC--Nuclear Regulatory Commission
PBT--Persistent, Bioaccumulative, and Toxic
RCRA--Resource Conservation and Recovery Act
RTHRM--Thermal Recovery (LDR Specified Treatment Method)
STABL--Stabilization (LDR Specified Treatment Method)
TC--Toxicity Characteristic
TCLP--Toxicity Characteristic Leaching Procedure
TOC--Total Organic Carbon
UHC--Underlying Hazardous Constituent
UTS--Universal Treatment Standard
WMNP--Waste Minimization National Plan

Table of Contents

I. General Information
    A. What is the LDR Program?
    B. What is the purpose of this LDR ANPRM?
    C. What has led up to this ANPRM?
    D. What issues does this ANPRM discuss?
    E. Who will these issues affect?
    F. How will this ANPRM impact small businesses and state 
programs?
    G. Will any potential changes arising from this ANPRM be more 
stringent than current requirements?
    H. When will any potential changes to the current LDR 
regulations take effect?
I. How do the issues presented in this ANPRM relate to other recent 
EPA notices?
II. Customer Service
    A. How can you influence EPA's thinking on this ANPRM?
III. How Can the LDR Program Further Encourage Source Reduction and 
Recycling?
    A. What does this section of the ANPRM discuss?
    B. Why do we want to further encourage source reduction and 
recycling?
    C. What are our ideas?
    D. What incentives would there be to choose source reduce and 
recycle?
    E. What potential new requirements would you have to satisfy?
    F. How could these suggested action affect current regulations?
    G. Could there be non-regulatory changes?
    H. Request for comment
IV. How Can the LDR Program Encourage the Use of Innovative Waste 
Treatment Technologies?
    A. What is the LDR Innovative Technology Evaluation (LDRite) 
Program?
    1. Why develop LDRite at this time?
    2. What are LDRite's goals?
    3. What is an innovative technology for purposes of the LDRite 
program?
    B. Who could be affected by LDRite?
    C. What should you expect from LDRite?
    D. What shouldn't you expect from LDRite?
    E. How will EPA ensure that innovative technologies are 
environmentally protective?
    F. Will EPA fund innovative technology development under LDRite?
    G. Request for comment
V. Issues Regarding the Effectiveness of Various Stabilization 
Practices Used to Immobilize Metal Wastes
    A. Background on LDR treatment standard program
    1. How have treatment standards been established?
    2. What improvements have been made to the LDR program?
    B. Background on treatment standards for metal-bearing hazardous 
waste

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    1. What are the metal-bearing wastes we regulate in the LDR 
program?
    2. How were treatment standards for metals established?
    3. Relevant treatment-related definitions
    C. Our questions about the metal treatment standards
    D. Current treatment processes used for the immobilization of 
metal waste
    1. Categories of treatment processes used to meet the standards 
for metal wastes
    2. Immobilization
    3. Details on stabilization
    4. Determining what type of stabilization is appropriate
    E. Specific metal treatment issues of interest
    1. Stabilization reagents--why are they a metal treatment issue?
    2. What is the importance of waste-to-reagent and water-to-
reagent ratios during metal treatment?
    3. How well is long-term immobilization being achieved?
    F. Potential changes based on these concerns
    1. Restricted disposal
    2. Specified treatment technologies
    3. pH controls
    4. Demonstration of waste stability over a pH range
    G. Request for comment
VI. Re-examination of the Spent Solvent (F001-F005) Treatment 
Standards
    A. What is EPA considering with respect to the treatment 
standards for spent solvents?
    B. Why is there a need to reexamine the spent solvent treatment 
standards?
    C. How does EPA regulate spent solvents?
    D. What are the characteristics of spent solvents and how do 
generators and treaters manage them?
    E. What are the levels of metal constituents in F001-F005?
    F. How might we change the regulations?
    G. Request for comment
VII. Reactive Wastes: Possible Revisions to Treatment Standards
    A. What is EPA's general concern?
    B. What are reactive wastes?
    C. What are the existing LDR treatment standards for reactive 
wastes?
    D. Are there specific reactive subcategories that merit 
attention?
    E. Request for comment
VIII. Public Input into Decisions on Determinations of Equivalent 
Treatment (DETs)
    A. What are DETs and what is the current system of considering 
DET petitions?
    B. Is a regulatory change needed?
    C. Request for comment
IX. Should EPA Revise the Macroencapsulation Alternative Treatment 
Standard for Hazardous Debris?
    A. What are the alternative treatment standards for hazardous 
debris?
    B. What is an HDPE vault?
    C. What is the issue with the HDPE vaults?
    D. Request for comment
X. Should EPA Establish a Special Category for Incineration Ash?
    A. What are we considering for incineration ash?
    B. What are the approaches we are considering for regulating 
incineration ash?
    C. How should the dioxin waste codes be regulated?
    D. Should we regulate specific constituents of concern in the 
ash?
    E. Would the incineration ash waste code be optional?
    F. Are there ways to reduce the analytical burden?
    G. Request for comment
XI. Should EPA Establish Tailored Treatment Standards for Mixed 
Wastes?
    A. What are mixed wastes?
    B. What are the issues associated with regulating mixed wastes?
    C. How has EPA responded to the issues associated with 
regulating mixed waste?
    D. What is EPA considering in this ANPRM?
    E. Request for comment
XII. Is EPA Addressing LDR Paperwork Burden in this ANPRM?
XIII. What Issues Are Not Addressed in this ANPRM?
XIV. Administrative Requirements
    A. Regulatory Flexibility Act
    B. Executive Order 13045

I. General Information

A. What Is the LDR Program?

    In 1984, Congress created EPA's Land Disposal Restrictions (LDR) 
program. The LDR program ensures that toxic constituents present in 
hazardous waste are properly treated before the hazardous waste is land 
disposed. The LDR program has developed technology-based treatment 
standards that all hazardous wastes must meet before they can be placed 
in a landfill. These standards help minimize short-term and long-term 
threats to human health and the environment.

B. What Is the Purpose of This LDR ANPRM?

    In this Advance Notice of Proposed Rulemaking (ANPRM), EPA is 
giving advance notice of issues and potential directions we are 
considering for improving the LDR program for treating hazardous waste 
under the Resource Conservation and Recovery Act (RCRA). We want to 
ensure that the LDR program is minimizing threats to human health and 
the environment in the most appropriate way. By appropriate we mean: 
(1) Environmentally protective; (2) cost-effective; (3) flexible for 
implementors and the regulated community; and (4) clear and 
enforceable.

C. What Has Led Up to This ANPRM?

    We interviewed representatives from EPA Headquarters, EPA Regions, 
States, and LDR experts in the regulated community and in environmental 
groups. These representatives identified problems, issues, and possible 
improvements to the LDR program. Next, we examined the recommendations 
made at the 1993 LDR roundtable \1\ to identify promising 
implementation ideas that have not been addressed. Finally, we 
conducted site visits with nine generators and treatment facilities to 
get first-hand knowledge of LDR implementation.
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    \1\ On January 13-14, 1993 EPA convened a roundtable to discuss 
potential improvements to the LDR program. The discussion topics 
included monitoring, administrative requirements/regulations, and 
treatment standards. Based on the discussions at the roundtable and 
our follow-up study of the issues from the roundtable, we made a 
number of changes to the LDR program. One of the changes involved 
the establishment of a single universal treatment standard (UTS) for 
most LDR-regulated constituents in wastewaters and nonwastewaters. 
The UTS eliminated situations in which a common constituent found in 
multiple wastes carried different numerical treatment standards (see 
59 FR 47982, September 19, 1994).
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    Through initial scoping activities described above, public comments 
submitted on past LDR proposed rules, public inquiries made to the 
Waste Treatment Branch, general experience working on LDR issues, and a 
second LDR roundtable held in 1998, we have compiled the issues, 
options, and directions listed and discussed below.

D. What Issues Does This ANPRM Discuss?

    This ANPRM presents several issues, options, and directions that 
could potentially lead to changes in the LDR regulations. Below is a 
list of issues that we are considering in this notice.
    (1) Ways for the LDR program to encourage the use of source 
reduction and recycling.
    (2) Ways for the LDR program to encourage innovative treatment 
technologies and to incorporate these technologies into the LDR 
program.
    (3) The long-term effectiveness of stabilization treatment for 
hazardous metal wastes. In particular, we are looking at whether metal 
constituents leach out of stabilized wastes over time and whether 
alternative approaches to evaluating the effectiveness of treatment by 
immobilization technologies exist.
    (4) Whether to develop treatment standards for additional 
constituents of concern (e.g., metals) in listed solvent wastes.
    (5) Whether better ways exist to ensure the treatment standards for 
reactive wastes are adequately protective.
    (6) Ways to allow public input into EPA's decision on requests for 
Determinations of Equivalent Treatment.
    (7) The appropriate regulatory response regarding the treatment

[[Page 37935]]

standards for hazardous debris and, in particular, look at whether 
macroencapsulation is the most appropriate treatment for debris 
contaminated primarily with organic compounds.
    (8) Whether to establish treatment standards for incineration ash 
to reduce paperwork burden and possibly reduce analytical costs 
associated with the carry through of multiple waste codes.
    (9) Whether to establish targeted treatment standards for 
radioactive mixed waste (i.e., wastes that are both hazardous under 
RCRA and radioactive) and consider other instances when it might be 
appropriate to establish methods of treatment rather than concentration 
limits to avoid radiological risks associated with compliance 
monitoring.

E. Who Will These Issues Affect?

    They potentially affect all those who are subject to the land 
disposal restrictions as well as implementors of the LDR program.

F. How Will This ANPRM Impact Small Businesses and State Programs?

    Because we are not proposing any new regulations in this notice, 
this ANPRM will not impact small businesses. We will, however, be 
mindful of the impact that any potential changes may have, and we are 
requesting comment on the potential costs and benefits to small 
businesses should revisions be made to the LDR program as described in 
this ANPRM. Suggestions on ways we might mitigate any adverse effects 
would also be welcome.
    We will also be cognizant of the impact of any proposed revisions 
to the LDR program on State programs, and we encourage comments on this 
subject.

G. Will Any Potential Changes Arising From This ANPRM Be More Stringent 
Than Current Requirements?

    It is premature to say at this point. Some of the possible changes 
may be more stringent, such as potentially regulating metal 
constituents in solvent wastes. Other potential changes may provide 
some relief to the regulated community, such as the possible 
establishment of tailored treatment standards for mixed wastes.

H. When Will Any Potential Changes to the Current LDR Regulations Take 
Effect?

    Our time frame for action in part depends on your comments and 
suggestions. We will thoroughly review your comments and suggestions to 
determine their feasibility, and any potential changes in the 
regulations will be proposed in future rulemakings.

I. How Do the Issues Presented in This ANPRM Relate to Other Recent EPA 
Notices?

    This ANPRM includes some issues that affect other recently released 
EPA notices. The following is a list of these notices, including a 
brief description of each notice and how it relates to this ANPRM:
    (1) ANPRM on potential revisions to the LDR mercury treatment 
standards (64 FR 28949, May 28, 1999)--gives advance notice of EPA's 
comprehensive reevaluation of the treatment standards for mercury-
bearing hazardous wastes as well as various options, issues, and data 
needs related to potential revisions to the mercury treatment 
standards. One of the options the mercury ANPRM discusses is the 
possibility of adding a subcategory to the LDR treatment standards for 
high mercury subcategory wastes that are also radioactive. See the 
section entitled ``Should EPA Establish Tailored Treatment Standards 
for Mixed Wastes?'' in this notice for more information.
    (2) Office of Solid Waste Burden Reduction Project Notice of Data 
Availability (64 FR 32859, June 19, 1999)--solicits comment on burden 
reduction options. See the section entitled ``Is EPA Doing Anything in 
this Rule to Decrease Paperwork Burden?'' in this notice for further 
information.
    (3) Hazardous Waste Identification Rule (HWIR) proposed rule (64 FR 
63381, November 19, 1999). HWIR contains two important areas of overlap 
with the RCRA LDR program. First, HWIR is requesting comment on whether 
HWIR exemption levels should ``cap'' existing technology-based LDR 
standards, where the exemption levels would be less stringent than the 
current LDR values. If a waste contains only constituents with 
``capped'' LDR values, it would satisfy LDR requirements and become 
exempt from the definition of hazardous waste for all other purposes 
once the other requirements of the HWIR exemption were satisfied. 
Second, if a listed waste is below the HWIR exemption concentrations 
where the waste is ``first'' generated (the point where a waste first 
meets the listing description) and the waste meets all the other 
requirements of the HWIR exemption, then a hazardous waste would never 
really be ``generated'' and the LDR requirements would not attach to 
the waste. In contrast, once a listed waste is generated and managed, 
the LDR requirements would attach, and the waste would need to meet 
LDRs before being disposed.

II. Customer Service

A. How Can You Influence EPA's Thinking on This ANPRM?

    In developing this ANPRM, we tried to address the concerns and 
viewpoints of a wide variety of stakeholders. Your comments will help 
us improve this ANPRM. We invite you to provide different views on 
options we describe, new approaches we have not considered, new data on 
how the options we describe may affect you, or other relevant 
information. We welcome your views on all aspects of this ANPRM and in 
particular on the items described in the ``Request for comment'' 
subsection found at the end of each preamble section. Your comments 
will be most effective if you follow the suggestions below:
     Explain your views as clearly as possible and why you feel 
that way.
     Provide solid technical and cost data to support your 
views. If you are going to submit technical data, make sure that it has 
been quality assured/quality controlled (QA/QC).
     If you estimate potential costs, explain how you arrived 
at the estimate.
     Tell us which parts you support, as well as those you 
disagree with.
     Provide specific examples to illustrate your concerns.
     Offer specific alternatives.
     Refer your comments to specific sections of the ANPRM, 
such as the units or page numbers of the preamble, or the regulatory 
sections.
     Make sure to submit your comments by the deadline in this 
notice.
     Be sure to include the name, date, and docket number with 
your comments.

III. How Can the LDR Program Further Encourage Source Reduction and 
Recycling?

A. What Does This Section of the ANPRM Discuss?

    This section asks the question: How can the LDR program further 
encourage source reduction and recycling? We request from you, the 
general public, (1) comments on the Agency's ideas to encourage source 
reduction and recycling; and (2) other suggestions on how this program 
can further encourage source reduction and recycling while meeting the 
Agency's policy objectives and legal standards.

B. Why Do We Want to Further Encourage Source Reduction and Recycling?

    One objective of the Resource Conservation and Recovery Act

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(RCRA)--the major hazardous waste statute--is to minimize 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 (see RCRA 
Sec. 1003(a)(6)). To further this objective, the Agency has set as 
goals of its Waste Minimization National Plan \2\ (WMNP) to:
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    \2\ See Waste Minimization National Plan, USEPA, 1994, EPA530-R-
94-045.
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    (1) Reduce, as a nation, the presence of the most persistent, 
bioaccumulative, and toxic (PBT) chemicals \3\ in RCRA hazardous wastes 
10 percent by the year 2000, and at least 50 percent by the year 2005 
(from a 1991 baseline);
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    \3\ PBT chemicals exhibit varying degrees of three properties: 
Persistent (P) chemicals do not readily breakdown in the 
environment; bioaccumulative (B) chemicals are not easily 
metabolized and can accumulate in human or ecological food chains 
through consumption or uptake; toxic (T) chemicals may be hazardous 
to human health or the environment in a variety of ways, depending 
on the chemical and the organism that is exposed. (63 FR 60332, 
November 9, 1998)
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    (2) Promote source reduction (and recycling where RCRA PBT 
chemicals cannot be reduced at the source) over treatment and disposal 
technologies; and
    (3) Avoid the transfer of RCRA PBT chemicals across environmental 
media.
    Consistent with the goals of RCRA and the WMNP, we are seeking 
ideas on how the LDR program can better or more directly encourage the 
reduction or elimination of hazardous waste generation through source 
reduction and recycling. Your comments and suggestions will help us 
reach our ultimate goal of incorporating source reduction and recycling 
processes as integral parts of our LDR program.

C. What Are Our Ideas?

(1) To Encourage Source Reduction: Set a Two-Part LDR Treatment 
Standard
    We are considering the usefulness and appropriateness of a two-part 
LDR treatment standard for wastes when we are revising hazardous waste 
treatment standards (such as with mercury hazardous wastes) and when we 
are setting treatment standards for newly listed hazardous wastes. The 
first part would be the establishment of a traditional standard, 
developed from data based on the best demonstrated available treatment 
technologies. This is essentially the way we set treatment standards 
today. The second and novel part would be to simultaneously develop an 
alternative standard that facilities could elect to use instead of the 
first, more traditional standard. This alternative standard would 
involve installing source reduction-oriented process changes that would 
reduce either the volume of waste produced or the concentration of the 
hazardous constituent in the wastes or both. We would develop 
incentives to encourage companies to comply with the alternative 
standard to move up the RCRA hierarchy.\4\ For example, if the 
alternative standard is elected, then as an incentive we could extend 
the effective date for a revised treatment standard beyond the 
traditional 90 days to allow time to implement the new process. We 
would determine the length of such an extension as we further develop 
our ideas.
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    \4\ In 1990, Congress passed the Pollution Prevention Act (PPA), 
in which they set forth the hierarchy of waste management options: 
Source reduction, recycling, treatment, disposal.
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    This source reduction treatment standard option is similar to a 
Pollution Prevention Compliance Option \5\ developed for characteristic 
wastewaters injected into Class I nonhazardous injection wells in the 
LDR Phase III rule. Under this alternative, mass reductions can be 
achieved by removing hazardous constituents from any of the waste 
streams that are going to be injected, and these reductions in mass 
loadings can be accomplished by means of source reduction (i.e., 
equipment or technology modifications, process or procedure 
modifications, reformulation or redesign of products, substitution of 
raw materials, and improvements in housekeeping, maintenance, training, 
or inventory control), recycling, or conventional treatment. This 
regulation along with others promulgated in the Phase III rule were 
superseded when the Land Disposal Program Flexibility Act of 1996 was 
signed. This statutory provision allows the land disposal of formerly 
characteristic wastewaters so long as they are not hazardous at the 
point they are land disposed.
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    \5\ Pollution Prevention Compliance Option developed and 
finalized in the LDR Phase III rules (Proposal 60 FR 11702, March 2, 
1995 and Final 61 FR 15566, April 8, 1996).
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(2) To Encourage Source Reduction for Wastes With Existing Treatment 
Standards: Establish a New Basis for Granting Treatment Variances
    We are considering adding a new basis for granting treatment 
variances. This new basis would allow facilities to petition for an 
alternative LDR treatment standard based on installing source 
reduction-oriented process changes. The petitioner would have to 
demonstrate the specific environmental benefits gained from the 
incorporation of the source reduction processes. This variance basis 
may lead to better overall environmental results (for example by 
reducing the amount of hazardous waste generated, by reducing the toxic 
constituent concentrations in the hazardous waste, or both).
(3) To Encourage recycling: (a) set Recycling as a Treatment Method for 
Certain Wastes or (b) Include Recycling as an Alternative Treatment 
Option for Certain Wastes
    We have developed a treatment standard for each hazardous waste 
code. Each treatment standard is either a set of maximum numerical 
concentration levels for the constituents in the waste, or a specified 
treatment technology. See 40 CFR 268.40(a). For seven waste codes,\6\ 
the treatment standards specifically require recycling. For example, 
RLEAD, or recovery of lead, is the required technology for the lead 
acid battery subcategory of D008 characteristic lead wastes. For seven 
other waste codes,\7\ the treatment standards include recycling as one 
of the treatment options. For example, in addition to STABL 
(stabilization), RTHRM (thermal recovery) is a specified treatment 
technology for P015, beryllium dust.
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    \6\ The seven waste codes that specify recycling as the 
treatment standard are D006--cadmium containing batteries, D008--
lead acid batteries, D009--high mercury subcategory of mercury-
bearing wastes, K069--emission control dust/sludge from secondary 
lead smelting non-calcium sulfate high lead subcategory, P015--
beryllium dust, P087--osmium tetroxide, and P113--thallic oxide.
    \7\ The seven waste codes that include recycling as one of the 
specified treatment standard options are D001--high total organic 
carbon (TOC), D001--high TOC ignitable characteristic liquids, 
P115--thallium (I) sulfate, U214--thallium (I) acetate, U215--
thallium (I) carbonate, U216--thallium (I) chloride, and U217--
thallium (I) nitrate).
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    We would like to revisit the standards that specify a recycling 
technology and investigate whether they are effective. If they are 
effective, we would consider adding recycling as a treatment method for 
other waste streams that have recoverable levels of constituents. For 
example, we could revise the LDR treatment standards for K171-spent 
hydrotreating catalyst from petroleum refining operations and K172-
spent hydrorefining catalyst from petroleum refining operations to 
require either metals recovery for vanadium and nickel or to include 
metals recovery as a treatment option to the current concentration-
based standards. On the other hand, if problems exist with the current 
recycling requirements, we would consider making useful adjustments as 
warranted.

[[Page 37937]]

D. What Incentives Would There Be To Choose Source Reduce and Recycle?

    As previously mentioned, one potential incentive we would consider 
is extending the effective date of the revised treatment standard 
beyond the traditional 90 days if we set an alternative two-part LDR 
treatment standard and you chose the source reduction part of the 
standard. We may also consider providing other types of incentives.
    One potentially positive outcome if we look into setting recycling 
as a treatment method is that we could investigate whether any 
recycling residues should remain hazardous wastes.
    We solicit your comments on additional incentives that could be 
provided.

E. What Potential New Requirements Would You Have To Satisfy?

    One potential avenue we could elect is to revise the treatment 
standards to encourage source reduction and recycling. Therefore, you 
might be subject to a revised set of treatment standards. In addition, 
for the treatment standards based on source reduction-oriented 
processes, we would consider requiring new administrative requirements 
such as contracts, milestones, or progress reports. These requirements 
would help us keep track of your implementation of source reduction 
processes at your facility.

F. How Could These Suggested Actions Affect Current Regulations?

    As a result of your comments and suggestions, some of the LDR 
treatment standards could change, while others might not. If we make 
regulatory changes, such as revising the treatment standards, then the 
treatment standards table at 40 CFR 40 CFR 268.40 may have additional 
subcategories. For example, the lead acid battery subcategory of D008 
characteristic lead wastes would not be changed so long as it remains 
environmentally beneficial to recover lead. We might choose to further 
subcategorize the general D008 characteristic lead wastes category into 
high and low categories. This new categorization could be based on the 
total lead concentration of the waste. We would then require a 
recycling treatment method for the high subcategory lead waste, while 
the low subcategory lead waste would remain subject to a numerical 
treatment standard.
    Also, we could make the LDR regulations more industry-specific for 
characteristic wastes. For example, we could set tailored source 
reduction and recycling-based treatment standards for arsenic 
characteristic wastes generated by the wood preserving industry. These 
are just a few of the impacts the Agency's potential actions could have 
on current regulations. At this early stage, we cannot completely 
anticipate the potential impacts various actions could have on current 
regulations. We solicit your comments on potential impacts.

G. Could There Be Non-Regulatory Changes?

    Our findings from this notice may or may not result in regulatory 
changes. We may instead choose to publish a guidance document with our 
findings and recommendations. Your comments and suggestions would help 
us to determine whether you would be more inclined to implement the 
ideas on your own using guidance or whether regulatory requirements 
would be needed to effect a change in your LDR compliance strategies.

H. Request for Comment

    Your comments and suggestions would help us to assess the 
feasibility of our ideas and where they could be most sensibly applied. 
Specifically, we request comment on (1) setting a two-part LDR 
standard; (2) establishing a new basis for granting treatment variances 
that sets alternative standards based on source reduction-oriented 
processes; and (3) setting or including recycling as a treatment method 
for certain wastes.
    Also, we would like comment on the best way to begin our efforts on 
encouraging source reduction and recycling. Should we start with a 
pilot project for source reduction and another for recycling? Do you 
know of any industries or waste codes that would be good candidates? 
Should we focus on waste codes or industries? Should we select those 
industries generating persistent, bioaccumulative, toxic chemicals? 
Should we target our efforts by volume of waste generated or focus on 
wastes that are generated by a significant number of generators? Should 
we target those wastes where a technology, such as stabilization, may 
not effectively treat a waste? What criteria should we use to assess 
recycling technologies? What criteria should we use to assess source 
reduction-oriented processes? What criteria should we use to establish 
a baseline for measuring the source reduction-oriented processes?
    Also, please include any other ideas on how the LDR program can 
further encourage source reduction and recycling. You should provide us 
with a detailed description of your idea, including process parameters, 
key limitations, time frame for implementation, company's corporate 
rate of return requirements, viable markets for the recycled product 
and if possible the potential industries or hazardous waste streams to 
which your idea could be applied. For any source reduction or recycling 
technology information that you submit, please include analytical 
performance data, if available. We will review your ideas and possibly 
develop further those ideas which are most feasible. Our next steps 
possibly could include either proposing those ideas in a future 
proposed rulemaking (if regulatory changes are required) or publishing 
a resource document.

IV. How Can The LDR Program Encourage The Use of Innovative Waste 
Treatment Technologies?

A. What Is the LDR Innovative Technology Evaluation (LDRite) Program?

    EPA's LDR program wants to explore how best to open the door to new 
and innovative waste treatment technologies that protect the 
environment and efficiently manage hazardous waste. Our venue for doing 
this will be under the aegis of a project we call LDR Innovative 
Technology Evaluation, or LDRite. This project has two basic near-term 
objectives--first, to help technology developers understand how their 
treatment systems could fit into the LDR waste treatment program and, 
second, to identify the most promising avenue for evaluating innovative 
waste treatment technologies--either formally or informally--that could 
help to further minimize threats to human health and the environment. 
Ultimately, we hope that LDRite will encourage the development of 
innovative waste treatment technologies that will offer us feasible 
regulatory alternatives to the technologies currently used to establish 
LDR treatment standards.
1. Why Develop LDRite at This Time?
    Before a hazardous waste is land disposed, organic and inorganic 
constituents of concern as well as hazardous waste characteristics 
(such as ignitability, corrosivity, reactivity) must meet standards 
that sufficiently minimize threats to human health and the environment. 
Our program accomplishes these goals by establishing technology-based 
treatment standards for hazardous wastes destined for land disposal. 
These LDR treatment standards are based on the performance

[[Page 37938]]

of best demonstrated available treatment (or BDAT) technologies \8\ and 
specify either numerical concentration-based performance standards or 
specified methods of treatment.\9\
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    \8\ The legislative history accompanying the 1984 Hazardous 
Solid Waste Amendment (HSWA) to RCRA states that a hazardous waste 
treatment method should be ``the best that has been demonstrated to 
be achievable.'' It also notes that Congress' intent is ``to require 
utilization of available technology'' and not a ``process which 
contemplates technology-forcing standards'' (Vol. 130 Cong. Rec. 
S9178 (daily edition, July 25, 1984)). The evident intent is to base 
treatment standards on the best technologies commonly in use and 
thus reasonably available to any generator. LDR treatment standards 
are generally based on the performance of the ``best demonstrated 
available technology,'' or BDAT. This approach involves identifying 
applicable treatment systems for individual wastes or for groups of 
wastes; determining whether these systems are ``demonstrated'' to 
achieve acceptably low effluent contaminant concentrations; and, 
determining if they are ``available'' commercially. For more 
information on this process, see the Final Best Demonstrated 
Available Technology (BDAT) Document for Quality Assurance/Quality 
Control Procedures and Methodology, USEPA, October 23, 1991.
    \9\ Generally, we prefer to set concentration-based treatment 
standards rather than technology-based treatment standards. 
Concentration-based treatment standards potentially offer the 
regulated community greater flexibility when developing and 
implementing hazardous waste compliance strategies. To meet 
concentration-based standards, waste treaters may use any technology 
method to treat their hazardous waste, as long as they comply with 
the numerical treatment standard. When complying with technology-
based treatment standards, however, treaters must treat the waste 
using the established technology. EPA intended the numeric-based 
standards to encourage development of innovative waste treatment 
technologies. We realize, however, that more incentives may be 
necessary.
---------------------------------------------------------------------------

    LDR treatment standards are currently based mainly on two dominant 
treatment technologies: incineration of organics and stabilization of 
metals. We recognize that the two technologies used to develop our 
treatment standards are quite traditional in character, which by itself 
is not necessarily a disadvantage and may reflect an expectable 
interplay between technical capability and economics. However, the 
field of hazardous waste treatment and recycling technologies is not 
static, and new technologies are being developed continually.
    For a number of reasons that we may understand and for others that 
we now may not, our historical experience in being able to incorporate 
technology innovations and evolutions into the LDR treatment standards 
has been quite limited. For example, the 1984 Hazardous Solid Waste 
Amendment to RCRA required EPA, in essence, to prohibit virtually all 
hazardous wastes from land disposal unless the waste first meets 
treatment standards established by EPA. In the 1984 Amendments, 
Congress gave us strict and tight deadlines for developing this myriad 
of treatment standards. It was not until May 26, 1998, some 14 years 
and over a dozen rulemakings later, that EPA concluded this task when 
we adopted the so-called Phase IV LDR rulemaking. See 63 FR 28556. 
Because of the sheer magnitude of this effort, our ability to search 
out, support, and incorporate innovative or non-traditional 
technologies were significantly constrained.
    Now, with the completion of the rulemakings needed to implement the 
1984 Amendments, we are in a better position to:
     Reassess BDAT technological frameworks used to establish 
the treatment standards to see if they still coincide with recent 
technology innovations,
     As appropriate, rethink earlier technical and policy 
decisions in light of recent and ongoing developments in the hazardous 
waste management field, and
     Refocus efforts to provide customer-oriented resources 
that help ensure hazardous waste destined for land disposal is managed 
in the most acceptable manner.
2. What Are LDRite's Goals?
    In pursuing these overall LDR goals, LDRite will create an 
environment more conducive to technology developers in the hazardous 
waste treatment arena by:
     Identifying the knowledge barriers that technology 
developers may encounter in looking at our RCRA waste treatment 
regulatory program,
     Taking concrete steps to ensure that the technology 
developers better understand the avenues by which EPA can learn about 
and evaluate their technologies; and ultimately
     Providing a well-defined process through which we may be 
able to incorporate improvements in waste treatment technology into our 
LDR program.
    As another potential benefit of the LDRite project, we would hope 
that innovative treatment and recycling technologies would also offer 
economic, cost-saving alternatives to hazardous waste facilities that 
need to be in compliance with our LDR treatment standards. Finally, we 
wish to build upon the successes of existing programs for technology 
innovation, such as the Environmental Technology Verification (http://www.epa.gov/etv) and the Small Business Innovative Research (http://www.epa.gov/ncerqa/sbir) programs. These are described in detail below. 
One of the key questions to be discussed between stakeholders and EPA 
is whether these programs offer as yet unrealized opportunities for 
technology developers to have an impact on the RCRA LDR treatment 
standards program or whether LDRite needs to be focused in a different 
manner.
3. What Is An Innovative Technology for the Purposes of the LDRite 
Program?
    We will generally consider a treatment technology to be innovative 
when:
     An existing BDAT technology is applied to a ``new'' 
hazardous waste stream \10\ and successfully treats or recycles this 
waste stream to meet or exceed existing treatment standards;
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    \10\ When determining applicable treatment technologies, wastes 
(i.e., waste streams or waste codes) may be clustered into so-called 
``treatability'' groups that have similar parameters which affect 
treatment success. These parameters can include physical state, 
water content, presence of similar hazardous and nonhazardous 
contaminants, organic content, heat content, pH, etc. Information on 
the waste characteristics of the treatability group are used to 
determine the applicable treatment technologies. The term ``new'' 
refers to a waste stream that a BDAT technology did not treat when 
LDR treatment standards were originally developed. The term ``old'' 
refers to a waste stream that was originally treated by BDAT 
technology used to develop the standard.
---------------------------------------------------------------------------

     An existing BDAT technology is modified and successfully 
treats or recycles hazardous waste streams (``new'' and ``old'') to 
meet or exceed existing treatment standards; or
     A new technology is developed to treat or recycle a 
hazardous waste stream to levels that meet or exceed existing treatment 
standards.
    The criteria used to define innovative technologies are meant to be 
general and non-exclusionary. Our intention is not to create narrow 
windows of opportunity but rather to provide a framework to understand 
our use of this term for LDR purposes in a fairly broad and 
unrestrictive way.

B. Who Could Be Affected by LDRite?

    This renewed emphasis on innovative technology development could 
affect any of the many entities that currently manage hazardous waste. 
We expect, however, that a partnership-oriented effort will provide 
positive impacts for everyone involved. For instance, as a hazardous 
waste:
     Generator you might choose an ``alternative'' innovative 
technology to manage your hazardous waste at lower cost,
     Treater you might adopt a more cost effective treatment 
process, and
     Innovative technology developer you might now have a way 
to further develop, refine, or market your technology.
    LDRite therefore has the potential to provide a platform from which 
we can

[[Page 37939]]

establish a solid understanding and common path forward with many types 
of stakeholders.

C. What Should You Expect From LDRite?

    We intend this preamble to lay out our LDRite objectives and also 
some potential avenues by which a greater use of innovative 
technologies in the RCRA waste treatment program could be achieved. We 
expect to engage in an open dialogue with technology developers, 
generators, treaters, disposers, federal and state agencies, and the 
public. We encourage you to comment on the objectives of LDRite, the 
suggestions and avenues that we identify below, and to add your ideas 
on how best to develop the LDRite project. We emphasize that, if our 
plans to move forward can be improved or even significantly redirected, 
we are willing to look closely at all suggestions in this regard. We 
hope to pool our thoughts and resources with yours, and to generate the 
most promising ways the LDR program and LDRite can encourage innovative 
technologies that protect the environment and that efficiently and 
economically manage hazardous waste.
    In an attempt to jump start your thinking and to elicit the most 
meaningful comments on this ANPRM, we are identifying below some steps 
that could be taken in the near future. Again, we emphasize that these 
steps are open to full discussion and can be modified or changed by 
your comments. Currently, EPA is looking into:
     Developing a ``match-making'' database system for the 
Internet--This database would allow innovative technology developers an 
opportunity to present their technologies (e.g., the type of waste the 
technology can treat, any available test data, etc.). Hazardous waste 
generators and treaters would also have a resource to research viable 
alternative treatment technologies using waste code and hazardous 
constituent information. One possibility is to expand an existing 
system, the Remediation and Characterization Innovative Technologies 
(REACH IT) database. The general vendor information provided for each 
technology could include:

Vendor name
Technology type
Trade name
Vendor address
Contact name and phone number
Patent and trademark information
Scale of technology (bench, pilot, or full)
The type of waste the technology could treat

     Linking current EPA technology advancement programs with 
innovative technology developers--These programs would help developers 
verify technology performance or finance technology development. 
Currently, the Environmental Technology Verification (ETV) program 
provides a mechanism for third-party verification of innovative 
technology performance. The Small Business Innovative Research (SBIR) 
program makes' awards to small firms for research and development of 
cutting-edge technologies.
    Of course, our ultimate step would be to modify current LDR 
treatment standards to incorporate or encourage the use of innovative 
technologies. We expect the LDRite project to illuminate ways in which 
this could be done in an effective and efficient manner. This is 
particularly important because pursuing a rulemaking effort to change 
LDR regulatory standards for waste treatment is a resource-intensive 
and time-consuming endeavor that cannot be undertaken lightly, 
especially in this era of constrained resources.

D. What Shouldn't You Expect From LDRite?

    We want to encourage development and promotion of innovative 
technology to meet environmental goals and standards. EPA cannot, 
however, commercially endorse specific technologies or promote specific 
companies even if they are acceptable or promising. Rather, we more 
appropriately set performance criteria and allow the regulated 
community flexibility in selecting among technologies.

E. How Will EPA Ensure That Innovative Technologies Are Environmentally 
Protective?

    EPA's mission is to protect human health and the environment. We 
want to encourage innovative technologies that promote the most 
effective and efficient protection of the environment possible. If 
current treatment technologies provide the best possible hazardous 
waste management option, then we would have significant difficulty 
changing our current LDR treatment standards absent a corresponding and 
substantial benefit (perhaps promoting greater source reduction).
    However, we want to keep pace with new technological advancements 
in the hazardous waste management field and to find opportunities to 
stimulate this field, whether they be regulatory or non-regulatory. One 
starting point, it would seem, is to make sure that technology 
developers understand how they could fit into the RCRA LDR regulatory 
development process. A clearly articulated and developer-friendly 
innovative technology evaluation process could help in this regard. As 
noted earlier, we will be examining how well other existing technology 
evaluation programs could serve the specific interest at issue here--
keeping the RCRA LDR treatment program current with waste treatment 
technology development. On the other hand, we do not need to be 
constrained by the parameters of those programs, especially if they 
serve needs that differ from ours. For example, selecting a remediation 
technology for a particular site of contamination may present a 
different set of considerations than developing nationally applicable 
LDR treatment standards for a given set of hazardous constituents. We 
hope to be able to identify both areas of commonality with and areas of 
difference from other existing programs.

F. Will EPA Fund Innovative Technology Development Under LDRite?

    The answer at this time is no. However, the following programs are 
designed to facilitate the development of new technologies in a variety 
of ways:
     The Environmental Technology Verification program (http://www.epa.gov/etv): ETV verifies the performance of commercial-ready 
technologies through the evaluation of objective and quality-assured 
data so that potential purchasers and permitters are provided with an 
independent and credible assessment of what they are buying and 
permitting. The ETV program is operated by EPA's Office of Research and 
Development and was created to substantially accelerate the entrance of 
environmental technologies into the domestic and international 
marketplace. EPA has selected ``verification partners'' to oversee and 
conduct the technology verification activities. These partners work 
with EPA technology experts and a variety of public and private 
stakeholders to develop procedures for verifying technology 
performance. For each technology verified, the partner develops a test 
plan, in conjunction with the developer, and the test is conducted by 
an independent third party. Following the test, a verification 
statement of 3-5 pages is issued by EPA, along with a data report.
     Small Business Innovative Research (http://www.epa.gov/ncerqa/sbir): For developers of technologies at the early stages of 
development and testing, EPA's SBIR program makes awards to small firms 
for research and development of cutting-edge technologies. The SBIR 
program is

[[Page 37940]]

intended to spawn commercial ventures that improve our environment and 
quality of life, create jobs, increase productivity and economic 
growth, and improve the international competitiveness of the U.S. 
technology industry. Over the past decade, dozens of innovative 
technologies and processes have emerged from this program. A number of 
these have moved quickly from ``proof of concept'' to 
commercialization. In other cases, companies are still seeking the 
start-up capital or other support needed to achieve commercialization 
of their technologies.

G. Request for Comment

    We recognize that the current regulatory environment, including the 
LDR treatment standards, may create unintentional barriers to 
innovative technology development in the hazardous waste arena. We want 
to know how you perceive this. Please tell us what part(s) of the LDR 
program you think inhibit innovative technology development and use, 
and what new initiatives would be beneficial in light of the goals and 
objectives set out above. For instance, you should think about the 
following points in preparing your comments:
     How can EPA help encourage innovative technology 
development via the LDR program, particularly with respect to what 
technology developers do or don't understand about the LDR program and 
the BDAT process by which our technology-based standards are developed 
from actual performance data?
     Will a ``match-making'' database system on the Internet 
facilitate the use of innovative technologies, and if so, what 
technology data should be included?
     Which existing EPA programs (e.g., ETV, SBIR) or parts of 
those programs would be useful in evaluating innovative technologies in 
the context of the LDR national treatment standards and of the BDAT 
concept that underlies these standards?
     Do technology developers have sufficiently detailed 
information on hazardous waste streams and the current cost of 
treatment to determine the most promising markets for new technologies? 
If not, what type of information is missing or hard to find for the 
developers?
     Are there ways, either formal or informal, in which we 
could better ensure that the hazardous waste treatment program evolves 
along with advancements in the hazardous waste treatment industry?
     How can the LDR program more effectively move up the 
hierarchy of hazardous waste management in conjunction with encouraging 
innovative technologies?
    We encourage you to submit your insights on areas within the LDR 
program that can potentially serve as vehicles to encourage innovative 
technology development. Your input will help us adjust, as appropriate, 
certain aspects of our program to encourage innovative technologies.
    If you have developed a technology that effectively reclaims, 
recycles, or treats regulated constituents in hazardous waste streams, 
please let us know. Information on your technology will keep us up-to-
date on new treatment options. You might also want to examine 
technologies we have identified to treat specific waste streams in 
EPA's Treatment Technology Background Document, January 1991. This may 
help you to demonstrate how your technology outperforms a technology 
used to establish a current LDR treatment standard.

V. Issues Regarding the Effectiveness of Various Stabilization 
Practices Used to Immobilize Metal Wastes

A. Background on LDR Treatment Standard Program

1. How Have Treatment Standards Been Established?
    The 1984 Hazardous and Solid Waste Amendments (HSWA) require that 
treatment standards must substantially diminish the toxicity or 
mobility of hazardous waste, so that short- and long-term threats to 
human health and the environment are minimized. (RCRA Section 
3004(m)(1), 42 U.S.C. 6924(m)(1)). We interpret long-term threats to be 
the residual hazards of a waste that will continue even after 
treatment, disposal, and the ultimate capping of the filled landfill 
cell. With regard to metals, treatment should impart a lasting measure 
of immobility to the metals of concern.
    Under EPA's LDR program, we have established treatment standards to 
implement the RCRA 3004(m) requirements. As mentioned in an earlier 
section of this notice, we have established two types of treatment 
standards: (1) a numerical concentration-based treatment limit for each 
constituent of concern, or (2) a method of treatment that must be used 
to treat a particular constituent or group of constituents. In either 
case, the treatment standard is based on a technology determined to be 
the ``Best Demonstrated Available Technology'' or BDAT.
2. What Improvements Have Been Made to the LDR Program?
    ``Our goal is to make the entire federal government both less 
expensive and more efficient * * * we intend to redesign, reinvent, to 
reinvigorate the entire national government. \11\
---------------------------------------------------------------------------

    \11\ President Bill Clinton's remarks announcing the National 
Performance Review, March 3, 1993.
---------------------------------------------------------------------------

    Over the last seven years, we have worked hard to find ways to 
improve the effectiveness of our work while still protecting human 
health and the environment. We believe that great strides have been 
made. One of our biggest LDR accomplishments has been the establishment 
of Universal Treatment Standards (UTS) (59 FR 47982, September 19, 
1994). This effort greatly simplified both compliance and enforcement 
with the LDRs without sacrificing protection of the environment or 
human health. The rule replaced multiple concentration levels for the 
same constituent across the LDR treatment standards with a uniform set 
of levels for each constituent. Another improvement to the program was 
the creation of alternative treatment standards for debris contaminated 
with hazardous waste (57 FR 37221, August 18, 1992). These treatment 
standards were tailored to address the specific problems encountered 
when manufactured objects, plant or animal matter, or natural geologic 
material (e.g., cobbles and boulders) become contaminated with a 
hazardous waste and are subsequently subject to LDR requirements.
    However, our work is not done. We remain committed to making 
quality improvements that will further improve the overall 
effectiveness and efficiency of the LDR program. Last July, EPA began 
implementation of a new set of administrative reforms, known as the 
RCRA Cleanup Reforms. These reforms are designed to achieve faster, 
more efficient cleanups at RCRA sites that treat, store, or dispose of 
hazardous waste and that have the potential for environmental 
contamination. The reforms are our comprehensive effort to address the 
key impediments to cleanups, maximize program flexibility, and spur 
progress toward a set of ambitious national cleanup goals.
    We are committed to ensuring that the LDR program incorporates 
these goals within its regulatory and policy framework. We have 
identified areas that need to be examined more carefully and we are 
working towards finding solutions to areas that may affect the 
accelerated and effective cleanups at corrective action sites. Progress 
has already been made. Early on we realized

[[Page 37941]]

that the treatment standards promulgated for as-generated waste would 
not always be achievable or appropriate for soil contaminated with 
hazardous waste and that the development of less stringent treatment 
standards was needed (59 FR 47980, September 19, 1994). In May 1998, we 
promulgated alternative treatment standards for contaminated soils 
subject to LDR. (See 63 FR 28556, May 26, 1998). The alternative soil 
standards provide the flexibility needed for achieving our cleanup 
goals. In the future, any additional revisions to the LDR program must 
be evaluated thoroughly to ensure that protection of human health and 
the environment is maintained and that efforts to facilitate cleanups 
are not compromised.

B. Background on Treatment Standards for Metal-Bearing Hazardous Waste

1. What Are the Metal-Bearing Wastes We Regulate in the LDR Program?
    In EPA's LDR program, we regulate two different types of metal-
bearing wastes: ``listed'' wastes with metals as regulated 
constituents; and ``characteristic'' metal wastes, which are regulated 
because they contain significant concentrations of mobile metal(s).\12\
---------------------------------------------------------------------------

    \12\ If the metal concentration is high enough, the waste may be 
characteristically hazardous for that metal. See the characteristic 
levels in 40 CFR 261.24. If the waste is characteristic for other 
reasons (e.g., organically toxic, corrosive, ignitable, or reactive) 
but not due to the metals, then a lesser concentration of metals may 
cause them to be subject to LDR standards as ``underlying hazardous 
constituents (UHCs).''
---------------------------------------------------------------------------

    Listed metal-bearing wastes are identified with a U, P, F, or K 
designation and contain one or more of the 14 metal constituents of 
concern identified in 40 CFR 268.40. Regulated metal constituents of 
concern are antimony, arsenic, barium, beryllium, cadmium, chromium, 
lead, mercury, nickel, selenium, silver, thallium, vanadium, and 
zinc.\13\
---------------------------------------------------------------------------

    \13\ A treatment standard for zinc has been established only for 
K061 waste. Zinc is not regulated in any other RCRA hazardous waste. 
Similarly, vanadium is a regulated constituent only in P119, 
P120,K171, and K172 wastes. Although zinc, vanadium, fluoride, and 
sulfide have UTS levels, they are not UHCs. However, EPA has 
required that some wastes meet UTS for these constituents because 
reaching these levels is additional evidence that treatment is 
effective.
---------------------------------------------------------------------------

    Characteristic metal wastes, identified as D004-D011, are defined 
as characteristic because the concentration of the toxic metal in the 
waste equals or exceeds a specified leachate concentration that is 
known to be a threat to human health and the environment. For example, 
a waste designated as ``D008'' is a waste which leaches lead at a 
concentration of 5 mg/L or greater using the Toxicity Characteristic 
Leaching Procedure (TCLP). The other RCRA characteristic metals are 
arsenic (D004), barium (D005), cadmium (D006), chromium (D007), mercury 
(D009), selenium (D010), and silver (D011). Since May 1990, 
characteristic metal wastes have had to undergo some type of treatment 
prior to land disposal.\14\
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    \14\ The Third Third Rule (55 FR 22520, June 1, 1990) required 
that characteristic metal wastes be treated to the characteristic 
level before disposal. Prior to that date, metal characteristic 
waste could be disposed in hazardous waste land disposal units 
without prior treatment. The recent Phase IV Rule (63 FR 28556, May 
26, 1998) required that these same wastes now meet the more 
stringent UTS listed at 40 CFR 268.48 before land disposal.
---------------------------------------------------------------------------

2. How Were the Treatment Standards for Metals Established?
    For metal-bearing wastes, we developed numerical, concentration-
based treatment standards based on performance data from two BDAT 
technologies: High temperature metals recovery (HTMR) and 
stabilization.\15\ We compared the performance of the two technologies 
and promulgated numerical treatment standards based on the higher of 
the calculated treatment standards to allow for waste variability and 
detection limit difficulties (63 FR 28561, May 26, 1998). By setting a 
standard as a numerical concentration limit, as opposed to a method of 
treatment, any type of treatment technology other than impermissible 
dilution can be used to achieve the standard (40 CFR 268.3).
---------------------------------------------------------------------------

    \15\ See `` Land Disposal Restrictions For Third Third Scheduled 
Wastes: Final Rule,'' 55 FR 22520, June 1, 1990; ``Land Disposal 
Restrictions Phase II--Universal Treatment Standards, and Treatment 
Standards for Organic Toxicity Characteristic Wastes and Newly 
Listed Wastes: Final Rule,'' 59 FR 47980, September 19, 1994; and 
``Land Disposal Restrictions Phase IV: Final Rule Promulgating 
Treatment Standards for Metal Wastes and Mineral Processing Wastes; 
Mineral Processing Secondary Materials and Bevill Exclusion Issues; 
Treatment Standards for Hazardous Soils, and Exclusion of Recycled 
Wood Preserving Wastewaters: Final Rule,'' 63 FR 28556, May 26, 
1998.
---------------------------------------------------------------------------

    Please note that the discussion in this part of the notice refers 
primarily to as-generated process waste. A specific discussion of how 
this issue may or may not relate to the alternative treatment standards 
for soil and debris is not presented, but we welcome comments on this 
subject.
3. Relevant Treatment-Related Definitions
    As mentioned earlier, an array of treatment technologies are 
capable of immobilizing metals in hazardous waste. For regulatory 
purposes, however, the LDR program has only defined two immobilization 
technologies: stabilization and macroencapsulation.\16\ Other 
technologies that perform immobilization functions are discussed in 
EPA's Treatment Technology Background Document \17\ and the 
descriptions used in that document will be followed in today's 
discussion. Other practices, however, have not been defined to date by 
EPA. We discuss these practices today in narrative form with as much 
detail as possible to accurately describe the process.
---------------------------------------------------------------------------

    \16\ Regulatory definitions for stabilization and 
macroencapsulation (40 CFR 268.42) have been developed as part of 
the LDR program because for some RCRA hazardous waste codes a method 
of treatment has been set as the treatment standard. When a method 
of treatment is set, one must use the treatment defined in 40 CFR 
268.42. However, if a numerical concentration-based treatment 
standard has been set, compliance with this standard can be achieved 
using any type of treatment other than impermissible dilution as 
defined in 40 CFR 268.3.
    \17\ The Treatment Technology Background Document, USEPA, 
January 1991 can be found in the RCRA docket supporting this rule.
---------------------------------------------------------------------------

    The following terms are used in the notice. Definitions printed in 
italics are regulatory terms (in 40 CFR 260.10 or 40 CFR 268.42) while 
the terms in standard typeface are not. We encourage you to provide us 
with any changes to the non-regulatory terms you think would be 
helpful. We are not, however, taking comment on the regulatory terms at 
this time. Additionally, you may submit information on any terms that 
we have neglected to present.

Definitions of Selected Terms

    Treatment--means any method, technique or process, including 
neutralization, designed to change the physical, chemical, or 
biological character or composition of any hazardous waste so as to 
neutralize such waste, or so as to recover energy or material resources 
from the waste, or so as to render such waste non-hazardous, or less 
hazardous; safer to transport, store, or dispose of; or amenable for 
recovery, amenable for storage, or reduced in volume.
    Immobilization--A broad class of technologies that reduces the 
solubility or leachability of the metal in the waste prior to land 
disposal. These technologies are designed to fix in place or position a 
metal constituent or constituents in a waste using physical, chemical 
or biological means so as to render such waste non-hazardous or less 
hazardous.
    Encapsulation--A family of processes wherein high-solids 
nonwastewaters are mixed with an organic polymeric substance or with 
asphalt. Mixtures are

[[Page 37942]]

then allowed to cure into a solid mass prior to disposal.
    Macroencapsulation--Macroencapsulation with surface coating 
materials such as polymeric organics (e.g., resins and plastics) or 
with a jacket of inert inorganic materials to substantially reduce 
surface exposure to potential leaching media. Macroencapsulation 
specifically does not include any material that would be classified as 
a tank or container according to 40 CFR 260.10.
    Neutralization--Means treatment with the following reagents (or 
waste reagents) or combinations of reagents: (1) Acids; (2) bases; or 
(3) water (including wastewaters) resulting in a pH greater than 2 but 
less than 12.5 as measured in the aqueous residuals.
    Precipitation--Chemical precipitation of metals or other inorganics 
as insoluble precipitates of oxides, hydroxides, carbonates, sulfides, 
sulfates, chlorides, fluorides, or phosphates. The following reagents 
(or waste reagents) are typically used alone or in combination: (1) 
Lime (i.e., containing oxides and/or hydroxides of calcium and/or 
magnesium); (2) caustic (i.e., sodium and/or potassium hydroxides); (3) 
soda ash (i.e., sodium carbonate); (4) sodium sulfide; (5) ferric 
sulfate or ferric chloride; (6) alum; or (7) sodium sulfate. Additional 
floculating, coagulation or similar reagents/processes that enhance 
sludge dewatering characteristics are not precluded from use.
    Solidification--Techniques that encapsulate the waste, forming a 
solid material of high structural integrity, and does not necessarily 
involve a chemical interaction between the contaminants and the 
solidifying additives.
    Stabilization--Stabilization with the following reagents (or waste 
reagents) or combination of reagents: (1) Portland cement; or (2) lime/
pozzolans (e.g., fly ash and cement kiln dust)--this does not preclude 
the addition of reagents (e.g., iron salts, silicates, and clays) 
designed to enhance the set/cure time and/or compressive strength, or 
to overall reduce the leachability of the metal or inorganic.
    Vitrification--A process involving the dissolution of waste at high 
temperatures with hazardous constituents incorporated into a glass or a 
glass-like matrix.

C. Our Questions About the Metal Treatment Standards

    Even though metals are land disposed within current regulatory 
requirements, their toxic properties make it imperative that they 
remain immobilized long after disposal, even after current land 
disposal cells have long ceased operation. Long-term stability of metal 
constituents in a land disposal environment is therefore a primary 
objective when determining the type of immobilization technology to be 
used.
    Our goals in this notice are to scrutinize specific immobilization 
activities as they pertain to metal bearing wastes, and also to:
    (1) Gather additional information on techniques currently being 
used to immobilize metals in both listed and characteristic wastes;
    (2) Identify additional cost-effective ways, if any, beyond current 
compliance testing by which both short-term and long-term effectiveness 
of immobilized waste can be assured; and
    (3) Solicit comment, information, and data on the observations, 
issues, and questions we present in this notice. In particular, we 
would like comments on alternative approaches to evaluating the 
effectiveness of treatment by immobilization technologies. We would 
also like comment on the amount of immobilization of metal-contaminated 
soils that takes place at corrective action sites and whether the 
points raised in this notice could adversely effect current efforts to 
encourage and facilitate cleanups.

D. Current Treatment Processes Used for the Immobilization of Metal 
Waste

1. Categories of Treatment Processes Used to Meet the Standards for 
Metal Wastes
    In meeting the numerical treatment standards, facilities generally 
employ two different categories of treatment processes for hazardous 
wastes containing metals: (1) Removal technologies that separate and 
recover metals contained in the hazardous waste for some type of reuse; 
and (2) Immobilization technologies that physically or chemically 
reduce the solubility or leachability of metals in the hazardous waste 
prior to land disposal.
    Removal technologies include treatments such as acid leaching, 
filtration, high temperature metals recovery (HTMR), ion exchange, and 
retorting. These technologies are generally conducted on wastes with 
metal concentrations greater than 1%. The choice of any one of these 
removal technologies is governed by the properties of the metal to be 
recovered as well as the actual physical and chemical characteristics 
of the waste itself.\18\ All of these technologies can be highly 
effective in the recovery of metals when properly applied.
---------------------------------------------------------------------------

    \18\ Of course, a facility's individual choice of removal over 
immobilization will also involve non-technical considerations, such 
as economics.
---------------------------------------------------------------------------

    Immobilization technologies are those technologies that reduce the 
solubility or leachability of the metal in the waste prior to land 
disposal. They do not remove the metal from the waste. Immobilization 
technologies typically promote physical and/or chemical changes within 
the waste to render the metals significantly less mobile and more 
resistant to leaching. Vitrification, macroencapsulation, and 
stabilization are examples of immobilization technologies. Usually, a 
metal-containing waste is treated with one of these technologies when 
the metal cannot be recovered or the concentration of the metal in the 
waste is too low to use a removal technology. In certain situations, 
however, the application of a removal technology can also require 
additional treatment of the residual (e.g., slag generated from high 
temperature metals recovery) by some type of immobilization. This type 
of immobilization is also the subject of this notice.
2. Immobilization
    As discussed above, immobilization is defined as a broad class of 
treatment methods designed to fix in place or position metal 
constituent(s) in a waste. To ensure treatment of a regulated 
constituent, any immobilization practice must impart a physical, 
chemical, or biological change to the metal or waste to render the 
waste non-hazardous or less hazardous. A variety of treatment 
technologies fall within the category of immobilization and are 
applicable to metal waste treatment.
    Analyses conducted for the LDR Phase IV rule suggest that treatment 
with cement or lime/pozzolans as well as other reagents (i.e., 
``stabilization'' as defined in 40 CFR 268.42) is the primary method of 
immobilization for the treatment of metal-bearing wastes.\19\ In the 
Phase IV final rule (63 FR 28556, May 26, 1998), we identified 
stabilization as the BDAT for metal wastes, and it is therefore the 
basis (along with HTMR) of our current numerical treatment standards 
for metals.
---------------------------------------------------------------------------

    \19\ See the capacity and economic analyses for the Phase IV 
metal treatment standards which can be found in the Phase IV final 
rule docket (docket number F-98-2P4F-FFFFF).
---------------------------------------------------------------------------

3. Details on Stabilization
    The basic principle of stabilization is that leachable metals in a 
waste are immobilized. For stabilization, this occurs following the 
addition of reagents, such as Portland cement, and other chemicals. 
Metal leachability is

[[Page 37943]]

reduced by the formation of a lattice structure and chemical bonds that 
bind the metals in the solid matrix, and thereby limit the amount of 
metal constituents that can be leached when water or a mild acid 
solution comes into contact with the treated waste material. 
Stabilization is most effective when the waste metal is in its least 
soluble state, thereby decreasing the potential for leaching. 
Pretreatment may be required to chemically reduce or oxidize the metal 
to a lower solubility state and achieve maximum stabilization 
performance. For example, hexavalent chromium is much more soluble and 
more difficult to stabilize than trivalent chromium.
    The two principal stabilization processes used are cement-based and 
lime/pozzolan-based processes. Stabilization processes can be modified 
through the use of additives, such as silicates, that control curing 
rates, reduce permeability, and enhance the immobilization properties 
of the solid material. Portland cement is a mixture of powdered oxides 
of calcium, silica, aluminum and iron produced by kiln burning of 
material rich in calcium and silica at high temperatures (i.e., 1400-
1500 deg.C). When the anhydrous powder is mixed with water, hydration 
occurs and the cement begins to set. The chemistry involved is complex 
because many different reactions occur depending on the composition of 
the cement mixture.
    As the cement begins to set, a colloidal gel of indefinite 
composition and structure is formed. Over time, the gel swells and 
forms a matrix composed of thin, interlacing, densely packed silicate 
fibrils. Constituents present in the waste (e.g., dissolved metals and 
hydroxides and carbonates of various metals) are incorporated into the 
interstices of the cement matrix. The high pH of the cement mixture 
(i.e., pH of 9-12) can keep some metals in the form of insoluble 
hydroxide and carbonate salts. It has been hypothesized that metal ions 
may also be incorporated into the crystal structure of the cement 
matrix. Oxoanionic metals (metals that form negative ions with oxygen), 
like arsenic and selenium, and divalent metals, like lead and cadmium, 
may not be as insoluble at high pHs.
    Pozzolan, which contains finely divided, noncrystalline silica 
(e.g., fly ash or components of cement kiln dust), is a material that 
is not itself cementitious, but becomes so upon the addition of lime. 
Metals in the waste are converted to insoluble silicates or hydroxides 
and are incorporated into interstices of the binder matrix, thereby 
inhibiting leaching.\20\
---------------------------------------------------------------------------

    \20\ For additional information on immobilization technologies, 
see the Treatment Technology Background Document, USEPA, January 
1991, which is in the docket supporting this notice. See also 
``Solidification/Stabilization and its Application to Waste 
Materials,'' EPA/530/R-93/012, June 1993.
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4. Determining What Type of Stabilization Is Appropriate
    In determining whether a particular stabilization treatment will 
meet the LDR treatment standards, several technical and practical 
considerations are relevant. For example, the following waste 
properties influence whether stabilization will be appropriate and 
effective long-term treatment for a waste: (1) Concentration of fine 
particulates; (2) the concentration of oil and grease; (3) the 
concentration of organic compounds; (4) the concentration of oxidizing, 
halide, sulfate and chloride compounds; (5) the solubility of the metal 
compound(s); and (6) other waste matrix constituents.\21\
---------------------------------------------------------------------------

    \21\ See ``Handbook for Stabilization/Solidification of 
Hazardous Wastes,'' EPA/540-2-86/001, Table 2-7, June 1986.
---------------------------------------------------------------------------

    Equally important is an examination of the design and operation of 
the stabilization process itself. To determine the effectiveness of a 
particular stabilization process, the following parameters need to be 
assessed: (1) The amount and type of stabilizing agent and additives; 
(2) the degree of mixing; (3) the residence time; (4) the stabilization 
temperature and humidity; and (5) the form of the metal compound. 
Optimization of all these factors (and perhaps others) can be necessary 
for effective treatment to occur.
    Because of these numerous technical and practical factors, it is 
obvious that effective metal stabilization is not a simple matter. 
Adding to this complexity are additional vagaries associated with the 
environmental conditions of the disposal site into which the stabilized 
metal matrix will be placed.\22\ For these reasons, we think an inquiry 
into current field practices and metal waste disposal sites is 
warranted to determine whether our current regulations and industry's 
current compliance practices are still minimizing threats to human 
health and the environment by substantially diminishing the toxicity of 
the waste or substantially reducing the likelihood of migration of 
metal constituents from the waste.
---------------------------------------------------------------------------

    \22\ The environment of the disposal facility may affect the 
long-term immobilization of metals in stabilized waste (e.g., the pH 
of the material in the disposal unit, buffering capacity, redox 
state, infiltration/rainfall rate, freeze/thaw potential.)
---------------------------------------------------------------------------

E. Specific Metal Treatment Issues of Interest

1. Stabilization Reagents--Why Are They a Metal Treatment Issue?
    The term stabilization is often used loosely in practice to refer 
to techniques that chemically reduce the hazard potential of a waste by 
converting the contaminants into less soluble, mobile, or toxic forms, 
either temporarily or permanently. The physical nature and handling 
characteristics of the waste are not necessarily changed. Some of these 
practices, while called stabilization, may not coincide with the 
concept of permanent treatment used by the Agency in the LDR program 
and discussed earlier in this notice.
    Stabilization, as per our regulatory definition, is a distinct 
treatment process defined primarily by the use of Portland cement or 
lime/pozzolans under specific operational conditions. Conversely, the 
term stabilization, as more broadly used in practice, can encompass the 
use of myriad other reagents including lime, cement kiln dust, 
phosphates, clay, modified clays, sulfide, activated carbon, and 
ferrous sulfate that can be used individually or in combination. Such 
reagents are intended to chemically alter the speciation of the metals 
to decrease solubility or aid subsequent treatment steps. Issues may 
therefore arise regarding the performance of various practices 
nominally regarded by industry as stabilization.
    For example, questions regarding actual chemical reactions 
occurring during treatment can emerge when long-term effectiveness is 
considered. In the Phase IV rule, the Agency codified the principle 
that the addition of iron metal in the form of fines, filings, or dust 
for the purpose of achieving a treatment standard for lead is 
``impermissible dilution'' under 40 CFR 268.3(d) (63 FR 28566, May 26, 
1998). We determined that this waste management practice, deemed 
stabilization by at least one industry, did not minimize threats posed 
by the land disposal of lead-containing hazardous waste. Specifically, 
we found that no chemical or pozzolanic reactions from the iron dust or 
filings occurred, and standard chemistry showed that metals, such as 
lead, were not bound into a non-leachable matrix when using iron dust 
or filings as a stabilizing agent. (See 63 FR 28566-69)
    This instance, as well as other anecdotal information, has raised 
the issue of appropriate use of stabilization

[[Page 37944]]

reagents in general. EPA is concerned that reliance may be currently 
placed on technologies that only temporarily immobilize the hazardous 
metals in as-generated waste through the addition of solubility-
modifying or pH-adjusting chemicals, which may enable the treated waste 
to pass the TCLP compliance test but do not actually immobilize the 
metals over the long term. Consequently, the choice of reagent can 
raise a question as to whether the mandate established by HSWA of 
minimizing short-term and long-term threats to human health and the 
environment is being satisfied.
    We therefore wish to inquire further about the use of reagents 
other than Portland cement and lime/pozzolans--such as phosphate- and 
silica-based reagents--and whether actual treatment occurs in a manner 
that in fact minimizes short-term and long-term threats to human health 
and the environment. It may well be that, upon closer scrutiny, use of 
these other reagents is, in fact, acceptable treatment for as-generated 
wastes under the LDR program. On the other hand, it is possible that, 
in some cases, the only effect of the reagent and stabilization process 
on the metal waste has been to show temporary immobility under the 
Agency's performance measure, the TCLP test conditions, prior to land 
disposal.
    The Agency's hypothesis is that reagents used in immobilization 
technologies differ in their ability to provide effective long-term 
treatment of metals in the treated waste. We have the following 
questions:
     What is the extent of the difference in immobilization 
technologies?
     Do certain immobilization technologies and reagents lose 
their ability to immobilize metals after land disposal has occurred?
     Alternatively, does the Agency's treatment measure, the 
TCLP, differ from actual management conditions to the degree that 
metals are never effectively mobilized under disposal conditions?
    Concerns about long-term stability and the waste's increase in 
volume also have been factors in past determinations of BDAT. For 
example, in the determination of the BDAT for arsenic wastes, volume 
increase, particularly with ferric co-precipitation, resulted in the 
selection of a different type of treatment technology as BDAT (55 FR 
22552, June 1, 1990). Data obtained during the development of the 
standards demonstrated that significantly high reagent to waste ratios 
would be required to maintain arsenic stability under alkaline pH 
conditions.\23\
---------------------------------------------------------------------------

    \23\ Final Best Demonstrated Available Technology (BDAT) 
Background Document for K031, K084, K101, K102, Characteristic 
Arsenic Wastes (D004), P and U Wastes Containing Arsenic and 
Selenium listing Constituents, USEPA, May 1990, page 4-9.
---------------------------------------------------------------------------

    We also wish to raise another concern about the use of treatment 
reagents that may impact operations beyond just those associated with 
stabilization. Reagents can also be used in a variety of other 
treatment settings, for example, as metal precipitation agents for 
incinerator scrubber water. At least one reagent being used in this 
context is itself a hazardous constituent, dithiocarbamate. This may 
not be a matter of concern in some situations since the point of 
compliance with LDR treatment standards for any underlying hazardous 
constituent is at the point of placement on the land.
    However, two scenarios may result in hazardous treatment reagents 
being placed on the land without being subject to testing for 
compliance with LDR standards. The first is when the reagent contains a 
hazardous constituent that is not identified as an underlying hazardous 
constituent in the original characteristic waste. The second is when 
the reagent contains a hazardous constituent that is not a regulated 
constituent for a listed waste.
    Similar to the issue regarding stabilization reagents that is 
discussed above, we are inquiring whether the use of reagents 
containing hazardous constituents is consistent with the short-term and 
long-term protection of human health and the environment, at least when 
LDR compliance does not take into account the levels of those 
constituents that are being placed on the land. We, of course, 
recognize the engineering value that these constituents may provide in 
a waste treatment train. Thus, we are particularly interested in 
comment on the levels of total and leachable hazardous constituent 
reagents being placed on the land and whether additional attention to 
this issue is warranted from the standpoint of treatment efficacy and 
protection of human health and the environment.
2. What Is the Importance of Waste to Reagent and Water to Reagent 
Ratios During Metal Treatment?
    Along with the selection of treatment reagents, the waste to 
reagent ratio is a critical performance parameter for effective 
stabilization to take place. Sufficient stabilizing material is 
necessary to facilitate the proper chemical reactions that allow for 
the binding of the waste constituents of concern (i.e., metals) into a 
treated matrix, making them less susceptible to leaching. The ratio of 
water to stabilizing agent (including water in the waste) is also 
important, impacting the strength and permeability characteristics of 
the stabilized material. Too much water will cause low strength; too 
little will make mixing difficult and, most importantly, may not allow 
the chemical reactions that bind the metals to be fully completed.
    We wish to inquire how reagent to waste ratios are being handled in 
practice during waste treatment operations. The use of excessive 
amounts of reagents (i.e., over treatment) may not be an appropriate or 
effective waste management practice, either from a technical or an 
economic standpoint. Excessive use of reagents can also lead to 
questions of impermissible dilution, i.e., whether concentration-based 
treatment standards are being met simply through physical dilution of 
the constituents, by the addition of inordinate amounts of reagent, in 
lieu of actual treatment involving chemical reactions between the 
reagent and the waste constituent. We request information on the waste 
to reagent ratios found in today's treatment operations in the field.
    Similarly, the amount of water used to facilitate the reaction is 
equally important and is an area of our inquiry. Certain practices, 
apparently, forego the use of any water to initiate a chemical reaction 
between the reagents and the waste. Thus, prior to the TCLP compliance 
test, the chemical reaction between the reagents and the waste does not 
occur. By definition, regulatory treatment also has not occurred in 
this instance. We request information on how much water is typically 
used to facilitate stabilization reactions. We also request information 
on practices that do not use water at all prior to the compliance test.
3. How Well is Long-Term Immobilization Being Achieved?
    Absent long-term studies on the stability of metal wastes in 
disposal units and in light of potential issues on the selection of 
reagents, we wish to inquire further about the long-term effectiveness 
and environmental benefits of certain immobilization technologies. The 
TCLP is the current compliance test, but this test was not specifically 
developed to be a performance measure of chemical precipitation 
procedures, of the long-term effectiveness of chemical additions, or of 
the potential for formation of toxic degradation products from added 
chelating agents. In

[[Page 37945]]

addition, flocculating agents such as dithiocarbamates, which form 
toxic complexes (detrimental to aquatic ecosystems) and has the 
potential to degrade to toxic carbon disulfide, are not precluded from 
use by existing regulation. These situations need to be further studied 
and evaluated by the Agency particularly in respect to the long-term 
effectiveness of the various treatment methods.
    As a preliminary step, we evaluated landfill leachate collection 
system data from 161 landfill cells operated by Waste Management, Inc. 
across the nation.\24\ The Waste Management, Inc. landfills receive 
predominately hazardous wastes. However, some sites receive only 
sanitary wastes, or a combination of sanitary and industrial wastes. We 
also evaluated data from the Reynolds Metals Company's facility in Gum 
Springs, Arkansas and Envirosafe Services of Ohio's facility in Oregon, 
Ohio.
---------------------------------------------------------------------------

    \24\ The data originally complied by Dr. Robert D. Gibbons of 
the University of Illinois at Chicago for Waste Management, Inc. is 
available in the docket for this notice.
---------------------------------------------------------------------------

    About 28% of the landfill cells from which we obtained data have 
actual leachate measurements in excess of the levels that would 
identify the leachates as characteristic hazardous wastes. Among the 
toxic metals, arsenic and cadmium have been most frequently observed at 
hazardous concentrations on both a total and dissolved constituent 
basis. In the long-term, these actual leachate concentrations suggest 
that significant groundwater contamination may result after the 
eventual failure of liners and other containment controls. Logic 
suggests that if compliance with the minimized threat standards were 
being achieved, leachate levels in excess of hazardous characteristic 
levels should not be observed in wastes that have met treatment 
standards before land disposal. However, actual disposal conditions may 
differ from those projected from the TCLP, and in part due to the 
influence of typical site-specific conditions.
    At Envirosafe's industrial waste landfill, which accepts 
predominantly stabilized K061 waste, high arsenic, cadmium, and zinc 
leachate levels were found. Similarly, arsenic and fluoride were 
observed at significant levels and pH was quite high in the leachate 
from the Reynolds' monofill receiving treated K088 waste (although 
fluoride and cyanide levels are significantly lower than leachate 
levels from untreated K088 wastes).
    Table 1 indicates the very limited and incomplete data currently in 
hand from these three sources. Although the TCLP is based on total 
metals analysis, we have provided both dissolved and total metal 
concentrations data in this table as reported in the data sources. 
Depending on how the metals analyses were conducted, total levels 
reported may not be directly comparable to the TCLP, as particulates 
may have been entrained in the samples. This could cause total metals 
analyses to show more metals than would leach if the tests were 
conducted in compliance with TCLP QA/QC protocols.

                             Table 1.--Observation of Landfill Leachate Properties a
----------------------------------------------------------------------------------------------------------------
                                                                      Number of    Percentage   Maximum leachate
            Parameter                                    Number of      cells       of Cells      concentration
                                                           cells        >TCLP         >TCLP          (mg/L)
----------------------------------------------------------------------------------------------------------------
pH...............................  ...................          213    5 (>12.5)           2.8         13.1
                                     .................                   1 (2.5)                        1.81
Arsenic..........................  Dissolved..........           80            9          11.3        120
                                   Total..............          152           29          19.1       1610
Barium...........................  Dissolved..........           66            0           0            9.7
                                   Total..............           91            0           0           43.8
Cadmium..........................  Dissolved..........           85            9          10.5        790
                                   Total..............          153           14           9.1        800
Chromium.........................  Hexavalent.........           29            1           2.7          5.2
                                   Dissolved..........           73            2           3.4          9.1
                                   Total..............          161           12           7.5        102
Lead.............................  Dissolved..........           84            1           1.2          8.9
                                   Total..............          125            5           4           72
Mercury..........................  Dissolved..........          125            0           0            0.05
                                   Total..............          152            7           4.6          2.3
Selenium.........................  Dissolved..........           90            1           1.1         12
                                   Total..............          157            6           3.8          5.2
Silver...........................  Dissolved..........           79            0           0            0.05
                                   Total..............          120            0           0            0.42
Total Number of Individual cells   ...................  ...........           46        b 28.2  ................
 with metals data.
----------------------------------------------------------------------------------------------------------------
a Landfills operated by Waste Management, Inc. receive hazardous, sanitary, and mixtures of hazardous and
  sanitary wastes.
b Calculation based on 163 cells with some metals data.

    A recent study published by researchers at California's Department 
of Toxic Substances Control \25\ found that the leachate concentrations 
of metals that form oxoanionic species (e.g., antimony, arsenic, 
molybdenum, selenium, and vanadium) in several leach tests (including 
the TCLP) did not always correlate closely with leachate concentrations 
obtained with actual municipal solid waste leachate (MSWL). For 
arsenic, molybdenum, and selenium the concentration levels in the 
leachate from the TCLP test were lower than the actual constituent 
concentrations found in the leachate extracted by the MSWL. For other 
metals, TCLP produced results approximately the same as the MSWL 
leachate results.
---------------------------------------------------------------------------

    \25\ See Environmental Science & Technology, Vol. 32 No. 23, pp. 
3825-3830, December 1, 1998.
---------------------------------------------------------------------------

    The Agency has initiated additional research focused on 
understanding the aspects of these tests (including the effects of pH 
and the chelating effects of the acetate and citrate used in the leach 
solutions) that can lead to over-or under prediction of results. In 
addition to our

[[Page 37946]]

own work, we wish to inquire further. We seek data and comment on 
metals in leachate from landfill cells, including the amounts of metal 
being disposed, the stabilization process used (and all key parameters 
such as reagent to waste ratios), and disposal conditions (i.e., waste 
pH, landfill leachate pH, amount of water infiltration, and cap 
integrity). We would also like leachate metals data from groundwater 
wells downgradient of the landfills, and any data on groundwater pH and 
groundwater net alkalinity over time. To date, we have only limited 
information on the specific wastes and associated treatment for 
individual landfill cells.

F. Potential Changes Based on These Concerns

    Below is a discussion of several approaches and areas in which we 
need additional information. We request comments on these approaches 
(individually or in combination) and data in support of your views, as 
well as any other information that addresses the issues and concerns 
identified in the preceding sections. Note that we are only asking for 
comments and information on these possible approaches, and that there 
are presently no plans to change the current LDR program as it pertains 
to metal treatment. If, however, proposed changes were to be developed, 
we would have to evaluate how any proposed changes would affect, if at 
all, the alternative treatment standards for soil and debris. Also, 
note that the primary focus of this notice is on as-generated process 
waste. We do, however, encourage comments on how any of these 
approaches could possibly affect the rapid cleanup of RCRA corrective 
action sites and CERCLA sites.
1. Restricted Disposal
    Heavy metals are generally toxic and certain metals (i.e., arsenic, 
selenium, and mercury) can be chemically altered (e.g., methylated by 
bacteria) into even more toxic and mobile species. To help insure the 
long-term immobility of metals, control of disposal conditions for the 
treated waste is an avenue to explore. Current regulations allow 
characteristic metal wastes to be disposed in nonhazardous waste 
landfills once the characteristic constituent(s), and any UHCs, meet 
UTS (40 CFR 268.40 and 40 CFR 268.44).\26\ To ensure disposal in more 
controlled conditions, one approach would be to confine disposal of 
these metal-bearing wastes to Subtitle C hazardous waste units, 
although, as just noted, this would significantly alter current rules 
regarding disposal of decharacterized waste.
---------------------------------------------------------------------------

    \26\ Note that, even if these wastes no longer exhibit a 
characteristic, they cannot be land disposed anywhere until they 
satisfy LDR requirements. Chemical Waste Management v. EPA, 976 F.2d 
2 (D.C. Cir. 1992).
---------------------------------------------------------------------------

    Furthermore, it may be appropriate to consider the pH of the waste 
and the landfill. It may be necessary to prohibit the disposal of a 
waste if it would cause the mobilization of hazardous constituents in 
the wastes that were previously disposed in the landfill. It may also 
be necessary to prohibit such a waste if the existing landfill 
conditions may cause the waste's toxic constituents to be mobilized. 
For example, mercury sulfide has been shown to be mobilized in the 
presence of excess sulfides in alkaline conditions.\27\ To maintain the 
long-term stability of these wastes, wastes that could create such 
conditions would have to be excluded from the disposal site, and the 
waste itself may have to be further treated to remove excess sulfides 
from the waste.
---------------------------------------------------------------------------

    \27\ H. Lawrence Clever, Susan A. Johnson, and M. Elizabeth 
Derrick, The Solubility of Mercury and Some Sparingly Soluble 
Mercury Salts in Water and Aqueous Electrolyte Solutions, J. Phys. 
Chem. Ref. Data, Vol. 14, No. 3, 1985, page 652.
---------------------------------------------------------------------------

2. Specified Treatment Technologies
    Another approach could be a limitation of allowable treatment 
technologies for metal-bearing wastes. By specifying more definitively 
the types of treatment allowed for metal as-generated wastes, we would 
no longer have concentration-based numerical treatment standards but 
specified methods of treatment. For example, if a treatment standard 
were based on stabilization using Portland cement as BDAT, we would 
specify that this is the only treatment reagent and process that could 
be used. The Agency is hesitant to implement this type of option, as we 
prefer to retain numerical, concentration-based standards.
    Retention of a performance-based approach, however, may require the 
development of additional testing requirements and land disposal 
standards based on these new tests if we conclude that long-term 
effectiveness of stabilization is not being achieved under current 
industry practices. Potentially, performance criteria could also be 
required to demonstrate adequate treatment by a specified technology.
3. pH Controls
    To achieve long-term stability and immobility of metal-bearing 
wastes, extreme pH conditions must be avoided. In certain situations, 
extremely alkaline wastes have not provided long-term treatment, but 
provided the appearance of treatment during compliance testing with the 
TCLP. In another example, arsenate species must be maintained between 
pH 3.0 and pH 8.0 under oxidizing conditions or arsenic species will be 
mobile in groundwater.\28\ Therefore, if arsenic-bearing materials are 
disposed with materials or reagents that are highly alkaline or acidic, 
then the potential for groundwater contamination would be greatly 
enhanced. Maintaining metal-bearing waste residuals between a pH 5.0 
and pH 8.0 would help maintain immobility of such arsenic-bearing 
wastes, but may be unsuitable for other wastes.
---------------------------------------------------------------------------

    \28\ Arsenic-Chemical Behavior and Treatment, David B. Vance. 
Can be found in the docket to today's notice and at http://
flash.net/nm2the4/arsenicart.htm.
---------------------------------------------------------------------------

4. Demonstration of Waste Stability Over a pH Range
    Current regulations only require that wastes be tested under one 
set of conditions. Because of the range of conditions that exist in 
landfill cells, a demonstration at a number of pH values covering the 
expected range of conditions could be required. Protocols may be 
developed that determine analyte solubility over the pH range. 
Compliance could be based in part on the solubility curve obtained from 
four parallel extractions using deionized water with nitric acid or 
sodium hydroxide. The extraction conditions could be as proposed by one 
group of researchers: \29\
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    \29\ Leaching Test Protocols; David Kosson, Andrew Garrabrants, 
Florence Sanchez, and Urshila Gulgule, Rutgers University, March 
1999. Can be found in the docket to today's notice.
---------------------------------------------------------------------------

    At a liquid to solids ratio of 5
     If natural pH5, then pH = 7, 9;
     If natural pH is between 5 and 9, then pH = 5, 7, 9;
     Extraction at natural pH.
     At a liquid to solids ratio of 0.5
     If natural pH>9, then pH = 5, 7, natural.
    More pH conditions could also be required for the construction of 
the apparent solubility curve as a function of pH, or extrapolated for 
each constituent using the above procedure. Mobility in the expected pH 
range of disposal above numerical limits could be prohibited. Again, we 
seek comment and data on the viability of such an option.

G. Request for Comment

    We desire long-term data for wastes treated by various 
technologies. We prefer actual field performance data, but we may be 
able to use bench

[[Page 37947]]

performance data, with initial and later characterization with standard 
leach protocols.
    We specifically request data from the landfill operators, including 
leachate collection system metal concentrations and pH, process 
descriptions, and associated treatability/performance testing data. As 
with any data submittal to EPA, well-documented Quality Assurance/
Quality Control (QA/QC) is critical to the Agency in evaluating and 
assessing the credibility of the data.
    We also seek your comments on the potential actions discussed 
herein that we could take to ensure that stabilization and 
immobilization practices are properly used to treat metal wastes. We 
want to make sure that threats to human health and the environment are 
minimized by the long-term stability and immobilization of metals in 
RCRA hazardous waste.

VI. Re-examination of the Spent Solvent (F001-F005) Treatment 
Standards

A. What is EPA Considering With Respect to the Treatment Standards for 
Spent Solvents?

    The classification of waste as an F001-F005 spent solvent waste is 
based upon two criteria: The concentration of the solvent in the virgin 
solvent mixture, and how the solvent is used. The virgin solvent must 
have been comprised of any solvent mixture or blend which contains at 
least, in total, 10% by volume of one or more listed solvents. See the 
F001-F005 listing descriptions (40 CFR 261.31). Also, the solvent must 
be ``spent'' and have been used for its ``solvent'' properties. A 
solvent is considered ``spent'' when it ``has been used and as a result 
of contamination can no longer serve the purpose for which it was 
produced without further processing.'' \30\
---------------------------------------------------------------------------

    \30\ See the Memo from Michael Shapiro, USEPA, to the Hazardous 
Waste Management Division Directors, USEPA Regions I-X, March 24, 
1994, for further clarification on the definition of spent material.
---------------------------------------------------------------------------

    In this section, we are revisiting the LDR treatment standards 
applicable to F001-F005 spent solvents to investigate whether we should 
require treatment of some (i.e., metals) or all hazardous constituents 
to their universal treatment standards (UTS) before land disposal. This 
section includes spent solvent characterization information, a 
discussion of the current solvent treatment standards, and a 
description of one option for revising the spent solvent regulations. A 
second related inquiry, which we discuss in another section of this 
ANPRM, is to add an F040 incinerator ash waste code with corresponding 
treatment standards. This ash code would presumably address the 
underlying hazardous constituents in the treatment residuals from the 
incineration of spent solvents.

B. Why Is There a Need To Reexamine the Spent Solvent Treatment 
Standards?

    When we established the treatment standards for listed solvent 
wastes in 1986, we did not also adopt treatment standards for metals or 
other hazardous constituents (e.g., organics other than those listed in 
the Table in 40 CFR 268.40). Therefore, under the current regulations, 
if a listed solvent waste is not also characteristic (i.e., the waste 
is not classified as any of the waste codes D001-D043), then treaters 
only have to treat the regulated constituents specified in the LDR 
table in 40 CFR 268.40. This means that they do not have to treat other 
hazardous constituents to the UTS levels set forth in the 40 CFR 268.48 
UTS table. Thus, the potential exists for some solvent wastes that 
contain other hazardous constituents above UTS to be treated only for 
the organics listed in the LDR table in 40 CFR 268.40. The treatment 
residuals would then be land disposed with these other hazardous 
constituents still above UTS. Note that a waste that exhibits a 
characteristic must be treated for underlying hazardous constituents 
(UHCs) prior to land disposal, so this same potential does not exist 
for listed spent solvents that are also characteristic wastes.\31\
---------------------------------------------------------------------------

    \31\ If a waste is both listed and characteristic, and one of 
the regulated constituents in the listing is also the basis for the 
characteristic, 40 CFR 268.9(b) states that the listed waste code 
will operate in lieu of the standard for the characteristic provided 
the treatment standard for the listed waste includes a treatment 
standard for the constituent that causes the waste to exhibit the 
characteristic. Otherwise, the waste must meet the treatment 
standards for all applicable listed and characteristic codes. For 
example, consider a K100 waste with cadmium and chromium at levels 
above UTS but below characteristic levels, and lead above 
characteristic level. This waste would be classified as both K100 
and D008. Since K100 is listed for cadmium, chromium, and lead, 
these three constituents must be treated to UTS. However, none of 
the other UHCs that may be present need to be treated to UTS.
---------------------------------------------------------------------------

    EPA typically does not require treatment of other hazardous 
constituents in listed wastes because in the listing and in the 
development of the treatment standards we have determined all of the 
hazardous constituents which are likely to be present.\32\ In these 
investigations, however, we have not accounted for the fact that 
solvents can mobilize, and therefore become contaminated with, 
significant concentrations of the other hazardous constituents they 
contact. Therefore, we are investigating whether we need to regulate 
metals and other hazardous constituents in F001-F005 spent solvent 
wastes to better protect human health and the environment.
---------------------------------------------------------------------------

    \32\ See the analyses in the BDAT Background Documents for each 
listed waste.
---------------------------------------------------------------------------

C. How Does EPA Regulate Spent Solvents?

    Spent solvents are listed hazardous wastes carrying the waste codes 
F001-F005. Thirty-two solvents are listed in the table in 40 CFR 
268.40. Thirty of these solvents have numerical treatment standards for 
the solvent itself; the other two, 2-Nitropropane and 2-Ethoxyethanol, 
have specified treatment technologies.
    Currently, an F001-F005 waste is required to be treated for UHCs 
only if the waste is characteristic. As noted above, if the solvent 
waste is not characteristic, then it may be disposed with other 
hazardous constituents above UTS levels and still be in compliance with 
the LDR regulations. Two scenarios exist where a spent solvent may have 
a hazardous constituent above a concentration of concern to EPA (in 
both scenarios, assume that the waste does not exhibit a 
characteristic):
    (1) The constituent is a toxicity characteristic (TC) metal or 
organic, and concentration is less than TC level, but above UTS.
    (2) The constituent is not a TC metal or organic, but concentration 
is above UTS.

D. What Are the Characteristics of Spent Solvents and How Do Generators 
and Treaters Manage Them?

    Nonwastewater spent solvents are usually either organic liquids or 
still bottoms from the recovery of F001-F005 spent solvents. The main 
technology for effectively treating the solvents is some form of 
combustion. Treaters must then ensure (typically via testing) that the 
incinerator ash complies with the treatment standards for the regulated 
solvent constituents in 40 CFR 268.40. If the ash is itself 
characteristic, most likely for metals, it is regarded as a newly-
generated waste and must be further treated to meet not only the 
treatment standard for the characteristic but also the UTS levels for 
any UHCs that are present.
    Nonwastewaters can also be derived from treating F001-F005 
wastewaters. These nonwastewaters will typically be a sludge that could 
have concentrated levels of metals, and therefore exhibit a 
characteristic. If the nonwastewater does exhibit a characteristic, 
that characteristic, and any UHCs, must be treated.
    Wastewater forms of F001-F005 are also generated. Most wastewaters 
are ``derived-from'' (i.e., they are generated

[[Page 37948]]

from the treatment, storage or disposal of listed hazardous wastes, and 
therefore remain hazardous wastes). See 40 CFR 261.3(c)(2). Examples 
include wastewaters contaminated with an F001-F005 solvent, scrubber 
waters from combustion units, and cooling waters from distillation 
units or strippers that get contaminated with solvents. Since most 
wastewaters are eventually co-mingled with other plant wastewaters, it 
is likely that other waste codes (and treatment standards) also apply. 
However, because many wastewaters are treated and discharged under 
National Pollutant Discharge Elimination System (NPDES) permits with no 
land disposal in the treatment train, the LDRs never apply to them 
(i.e., they are restricted wastes, but not prohibited wastes, since 
they are not land disposed).

E. What Are the Levels of Metal Constituents in F001-F005?

    The ``Best Demonstrated Available Technology (BDAT) Background 
Document for F001-F005 Spent Solvents,'' November 1986, presents nine 
data sets on incinerator ash from the combustion of hazardous wastes, 
including spent solvents. The data show that metal concentrations in 
the incinerator ash are mostly below UTS levels. There are no instances 
in which the metal concentration is above the TC level, and only two 
cases in which the metal concentration is above the UTS but below TC 
levels. One of these two instances is for lead and the other is for 
chromium.
    Although this background document suggests that metals are not 
ubiquitous in treated wastes that contain spent solvents, more current 
information from the 1995 Biennial Reporting System (BRS) shows that 
often an F001-F005 waste stream is also characteristic for one of the 
metals. A preliminary review of the 1995 BRS shows that about 20% of 
the F001-F005 waste streams also carry at least one of the 
characteristic metal codes (i.e., D004-D011), with about 15% carrying 
two or more characteristic metal codes. Lead and chromium are the 
metals that are most frequently present; each is found in about 15% of 
the spent solvent waste streams.
    This information is informative but not necessarily dispositive. 
Although the BRS provides a general idea of how much hazardous waste is 
generated, we want to point out three issues with respect to the F001-
F005 BRS data. One is that the BRS does not include actual metal 
concentrations in the waste streams, even though the waste streams are 
reported as characteristic for metal. Thus, it is very difficult to 
accurately estimate the range of metal concentrations found in spent 
solvent wastes, except through making assumptions that may or may not 
reflect reality. Nevertheless, because these data show that about 20% 
are reported as characteristic for metals, one could draw an inference 
that metals are present in these and potentially other spent solvent 
waste streams at levels that warrant further investigation.
    A second issue is that the BRS does not provide any information on 
other recognized toxic metals that, by themselves, would not render a 
spent solvent characteristic. These metals include antimony, beryllium, 
nickel, and thallium, each of which appear on the list of hazardous 
constituents in Appendix VIII of Part 261. Thus, we cannot estimate 
from the BRS the extent that these metals may be present or in what 
concentrations.
    Finally, although 20% of the spent solvents waste streams also have 
a characteristic metal code (and therefore require treatment of all 
UHCs reasonably expected to be present), we do not know the metal 
concentrations in the other 80% of the waste streams. This raises at 
least the potential for these streams to have metal concentrations 
above UTS. For all of these reasons, we are interested in a more 
complete characterization of metal constituents and concentrations in 
F001-F005 spent solvents and we invite data and detailed comments on 
this subject.

F. How Might We Change the Regulations?

    Although the previous section focused solely on metals in spent 
solvents, we are more generally concerned about all hazardous 
constituents in spent solvents. As was alluded too earlier, solvent 
wastes are generated in a wide variety of settings and are prone to 
contamination with almost any hazardous constituent (depending upon 
where the solvents were used) since one of the main purposes of 
solvents is to mobilize whatever they come in contact with.
    To ensure that all hazardous constituents in treated solvent wastes 
are at concentrations that reflect BDAT and minimize threats to human 
health and the environment, we are asking for comment on whether we 
should require treatment of all other hazardous constituents (or 
possibly just metals) in spent solvent wastes to UTS levels (see 40 CFR 
268.48). This regulatory change would essentially adopt the same LDR 
regime for these listed solvent wastes as for characteristic wastes.
    In extending this concept to F001-F005 spent solvents, we may need 
only to focus on metals since treatment via high temperature combustion 
would likely destroy all organics and the only remaining compounds of 
concern from the original spent solvent waste would be metals. However, 
as noted above, we are interested in comment on whether any technical 
or implementation considerations exist that would lead to requiring 
treatment of all hazardous constituents, not just metals, that are 
present in the F001-F005 wastes.
    A second approach is to develop a new waste code (F040) for 
incinerator ash, and not to focus our attention on hazardous 
constituents in the original F001-F005 spent solvent waste that is 
going to high temperature combustion. We discuss the need for an ash 
waste code in this ANPRM in the section titled ``Should EPA Establish 
Special Categories of Waste Residuals?'' Since many solvent 
nonwastewaters are combusted, metal concentrations in spent solvents 
could be adequately controlled by the treatment standards for the ash 
waste code. As noted in this other section in more detail, we seek 
comment on the various advantages and disadvantages of this approach.

G. Request for Comment

    We are seeking comment on all aspects of the potential changes to 
the F001-F005 waste codes. In particular, we would like comments and 
information on the following:
    (1) F001-F005 characterization data, both before and after 
treatment (including total and TCLP metal concentrations);
    (2) The need for a change to the current spent solvent regulations. 
What information can you provide on the current treatment practices for 
F001-F005 solvent wastes?
    (3) If a change is necessary, which regulatory option do you 
prefer? We specifically invite comment on the option described in 
Section F, and on the addition of an F040 waste code for incinerator 
ash. Would treatment standards for the F040 waste code ensure that 
spent solvents are properly treated and disposed? We are also 
interested in other options you may prefer.
    (4) What are the possible impacts of changing the regulations? 
Would there be a substantial increase/decrease in the amount of 
required sampling and analyses? Are there any capacity considerations 
that need to be analyzed?

[[Page 37949]]

VII. Reactive Wastes: Possible Revisions to Treatment Standards

A. What Is EPA's General Concern?

    The LDR treatment standards for reactive wastes require that the 
waste no longer exhibit the characteristic of reactivity, but do not 
require destruction of the agents in the wastes that cause the waste to 
be reactive. Also, certain members of the regulated community have 
expressed uncertainty in how to evaluate wastes for reactivity, either 
before or after treatment, and have requested guidance. The Agency is 
therefore asking whether this type of guidance is generally needed and 
also whether the LDR treatment standards for these reactive wastes need 
to be revised to more effectively minimize long-term threats to human 
health and the environment.

B. What Are Reactive Wastes?

    40 CFR 261.23 defines wastes having the characteristics of 
reactivity (classified as D003 wastes) as those that have any one of 
the following properties:
    (1) It is normally unstable and readily undergoes violent change 
without detonating;
    (2) It reacts violently with water;
    (3) It forms potentially explosive mixtures with water;
    (4) When mixed with water, it generates toxic gases, vapors or 
fumes in a quantity sufficient to present a danger to human health or 
the environment;
    (5) It is a cyanide or sulfide bearing waste which, when exposed to 
pH conditions between 2 and 12.5, can generate toxic gases, vapors or 
fumes in a quantity sufficient to present a danger to human health or 
the environment;
    (6) It is capable of detonation or explosive reaction if subjected 
to a strong initiating source or heated under confinement;
    (7) It is readily capable of detonation, explosive decomposition or 
reaction at standard temperature and pressure;
    (8) It is a forbidden explosive as defined in 49 CFR 173.51, a 
Class A explosive as defined in 49 CFR 173.53, or a Class B explosive 
as defined in 49 CFR 173.88.\33\
---------------------------------------------------------------------------

    \33\ References to 49 CFR in 40 CFR 261.23 to explosive classes 
have been subsequently renamed and renumbered since the promulgation 
of 40 CFR 261.23. See 55 FR 52617, December 21, 1990. Definition of 
forbidden explosives is now found at 49 CFR 173.53, and definition 
of Class A and B explosives are found at 49 CFR 173.50. See also 49 
CFR 173.53 to compare old and new hazard class names.
---------------------------------------------------------------------------

    Several listed wastes are also considered reactive: K044, K045 and 
K047, wastes from the manufacture and processing of explosives. These 
wastes were listed solely for reactivity, and contain a number of 
explosive components which, if improperly managed, could pose a 
substantial hazard.\34\
---------------------------------------------------------------------------

    \34\ Listing Background Document, USEPA, 1980, page 651, which 
is in the docket for this notice.
---------------------------------------------------------------------------

C. What Are the Existing LDR Treatment Standards for Reactive Wastes?

    The treatment standard for the reactive wastes, other than the 
cyanide subcategory wastes, is deactivation, abbreviated in the 40 CFR 
268.40 treatment table as ``DEACT.'' DEACT requires only that the 
wastes must be treated to remove the characteristic prior to land 
disposal. The constituent that originally caused the waste to exhibit 
reactivity is not specifically required to be destroyed or separately 
treated. In addition to DEACT, explosives, water reactives, and other 
reactives subcategory D003 characteristic wastes must be treated to 
meet universal treatment standards (UTS) for any underlying hazardous 
constituents (UHCs) reasonably expected to be present in the waste.\35\ 
See Table 2 for the list of the treatment standards.
---------------------------------------------------------------------------

    \35\ When managed in CWA/CWA-equivalent/Class I SDWA systems, 
explosives, other reactives, and water reactive wastes may be 
diluted to remove the characteristic, without consideration of 
underlying constituents.

            Table 2.--Treatment Standards for Reactive Wastes
------------------------------------------------------------------------
                                                        Nonwastewater
         Waste code             Waste description    treatment standard
------------------------------------------------------------------------
D003........................  reactive sulfides     DEACT.
                               subcategory.
                              explosives            DEACT and meet
                               subcategory.          268.48 standards.
                              unexploded ordnance   DEACT.
                               and other explosive
                               devices which have
                               been the subject of
                               an emergency
                               response.
                              other reactives       DEACT and meet
                               subcategory.          268.48 standards.
                              water reactive        DEACT and meet
                               subcategory.          268.48 standards.
                              reactive cyanides     590 mg/kg total, 30
                               subcategory.          mg/kg amenable.
K044........................  wastewater treatment  DEACT.
                               sludges from the
                               manufacturing and
                               processing of
                               explosives.
K045........................  spent carbon from     DEACT.
                               the treatment of
                               wastewater
                               containing
                               explosives.
K047........................  pink/red water from   DEACT.
                               TNT operations.
------------------------------------------------------------------------

D. Are There Specific Reactive Subcategories That Merit Attention?

    Yes. Several subcategories of reactive characteristic wastes appear 
in our LDR regulations. We are most interested in the waste 
subcategories that require only DEACT as the treatment standard. Two 
key issues exist in particular. First, where other, non-reactive 
hazardous constituents are expected to exist, these constituents may 
warrant individual treatment attention. Our current treatment standards 
do not always require this to occur. Table 2 illustrates how DEACT is 
specified for each subcategory of D003 wastes (with the exception of 
the reactive cyanides subcategory) and for K044, K045 and K047. UHCs or 
other hazardous constituents expected to be present (known as regulated 
constituents in listed wastes) are only included in the treatment 
standards for the following wastes: D003 explosives, other reactives, 
and water reactives subcategories.
    Second, DEACT does not require treatment (destruction) of the 
constituent causing the waste to be reactive, but rather allows any 
method (including dilution in the case of Clean Water Act, or CWA, 
systems) to be used to remove the characteristic of reactivity. In the 
preamble to the Third Third Rule (55 FR 22552, June 1, 1990), EPA noted 
that it had selected deactivation because technologies exist that can 
remove the characteristic, and that the general standard would allow

[[Page 37950]]

the regulated community flexibility to use whichever treatment 
technology that best fits the type of waste; see also Chemical Waste 
Management v. EPA, 976 F.2d 2, 18 (D.C. Cir. 1992), where the court 
upheld the deactivation standard for wastes identified because they 
exhibit the characteristic of reactivity.
    Current regulations provide, at 40 CFR 268 Appendix VI, recommended 
technologies for the treatment of water reactive, reactive sulfide, 
explosive, other reactive subcategories of D003 characteristic wastes, 
and K044, K045 and K047 listed wastes. Again, these technologies are 
not required.
    By not requiring a technology that destroys or permanently treats 
the characteristic causing the reactivity, we lack a means to measure 
whether a waste or waste constituent is still reactive over the long 
term. This becomes a concern, for example, when many of the listed and 
characteristic explosive subcategory reactive wastes are simply kept 
moist to make it safer to handle them. Because ``DEACT'' is narratively 
defined in section 261.23, wetting of material may be treatment in the 
short term, but is not necessarily a permanent treatment. The 
definition of ``DEACT'' has been implemented in practice to include 
wetting, even though it may be only temporarily effective. Furthermore, 
generators have in some cases determined that their wastes when wetted 
are not reactive and not subject to treatment standards even though 
explosive residues may form through evaporation. This raises the 
question about the timing of a determination of compliance (in this 
case, removal of a characteristic) with uncertain future events that 
may significantly change the nature of the waste.

E. Request for Comment

    We are requesting comment on the possibility of modifying the 
treatment standards. One option would be to include a requirement to 
destroy the reactive constituents in the waste. Possible technologies 
include chemical oxidation (CHOXD); chemical reduction (CHRED); 
biodegradation (BIODG); or combustion (CMBST). These are some of the 
technologies recommended in 40 CFR 268 Appendix VI. We are also 
requesting comment on the possibility of adding the requirement to 
treat UHCs for the characteristic subcategories for which that 
requirement does not already exist and, in the case of the listed 
reactive wastes, to require treatment of specific hazardous metals 
which are also expected to be present.
    We are also requesting data identifying the wastes, waste volumes, 
current treatment, and any additional treatment costs associated with 
alternative treatments that might better treat these wastes.

VIII. Public Input Into Decisions on Determinations of Equivalent 
Treatment (DETs)

    At the 1998 LDR roundtable, we heard from environmental groups that 
we should allow the public to comment on Determinations of Equivalent 
Treatment (DET) granted under 40 CFR 268.42(b). The underlying concern 
is that the public has no voice in the decision making process that may 
have an impact on hazardous waste treatment in their own communities.

A. What Are DETs and What Is the Current System of Considering DET 
Petitions?

    A DET is a variance that may be granted for a hazardous waste at a 
particular site for which the LDR treatment standard is a required 
method of treatment. It is based upon a demonstration to EPA that 
another treatment technology performs as well as the one required under 
the LDR treatment standard. If it is granted, the alternative 
technology becomes the treatment standard that must be used on that 
waste at a particular site.
    Currently, the regulated community petitions EPA for a DET. These 
petitions generally contain data to show that the alternative treatment 
method provides a measure of performance equivalent to the one 
established as the treatment standard. These petitions also contain 
information on the facility generating the waste, the volume of the 
waste, where it is disposed, and other information relevant to the 
petition. We consider the petition and data, and then grant or deny the 
request in writing based upon its technical merits. We then inform the 
petitioner of our decision.
    Under EPA's current regulations, public participation is not 
required in the process of evaluating a DET petition. In contrast, 
public participation is required for a related process involving 
treatment variances (see 40 CFR 268.44(e)). Under this process, we give 
public notice in the Federal Register of our intent to grant or deny 
the treatment variance and then again of our final decision. The 
treatability variances granted under 40 CFR 268.44(e) are very similar 
to DETs in that they establish alternative treatment standards for a 
waste. They differ from DETs in that they are granted in cases when the 
treatment standard is expressed as concentration levels rather than 
required methods of treatment, and the substantive grounds for granting 
treatment variances are different from those for DETs.

B. Is A Regulatory Change Needed?

    We have recently begun publishing DETs in the Federal Register with 
a comment period without a regulatory change. \36\ We are considering 
whether also to change the regulations at 40 CFR 268.42(b) to require 
EPA to seek public comment on most DET requests. \37\ Public comment 
would be solicited on EPA's draft decision to grant or deny the DET 
request. Public comments could be solicited through such vehicles as 
the Federal Register, for instance, or other outlets such as local 
newspapers. We expect most comments would address the merits of the 
proposed technology for the waste in question. The comments received 
would then be factored into EPA's final decision. The written final 
decision could be announced in the Federal Register or other vehicle 
such as a local newspaper.
---------------------------------------------------------------------------

    \36\ See 64 FR 51540, September 23, 1999 for an example of a 
proposed DET in the Federal Register.
    \37\ EPA would reserve the option to waive this requirement if, 
in our judgement, delay would result in significant damage to human 
health and the environment.
---------------------------------------------------------------------------

C. Request for Comment

    We solicit comments on the need for a regulation regarding public 
participation in the DET process, and on whether EPA's current practice 
is sufficient. Furthermore, we solicit information on the length of 
time that would be appropriate for public participation, and the media 
vehicles that should be used to solicit comments. Is there a need for 
different public participation requirements than for treatment 
variances? Are there any disadvantages to the increased public 
participation, other than time delays for issuing the variance?

IX. Should EPA Revise the Macroencapsulation Alternative Treatment 
Standard for Hazardous Debris?

    In a petition for rulemaking (available in the docket for this 
ANPRM), filed on December 16, 1998, the Environmental Technology 
Council (ETC), the National Association of Chemical Recyclers, and the 
Cement Kiln Recycling Coalition request EPA to amend the alternative 
treatment standards for hazardous debris to restrict the use of 
macroencapsulation for debris contaminated with significant amounts of 
organic hazardous constituents. ETC is particularly focused on the 
effectiveness of using high density

[[Page 37951]]

polyethylene vaults for macroencapsulating hazardous debris.

A. What Are the Alternative Treatment Standards for Hazardous Debris?

    On August 12, 1992, EPA promulgated alternative treatment standards 
for hazardous debris (57 FR 37195). Hazardous debris is defined as 
debris that either contains a listed hazardous waste, or exhibits a 
characteristic of hazardous waste (see 40 CFR 268.2(h)). The 
alternative treatment standards for hazardous debris are listed in the 
table at 40 CFR 268.45.
    The 17 treatment technologies listed in 40 CFR 268.45 are divided 
into three categories: extraction, destruction, and immobilization. The 
extraction and destruction technologies are designed to separate the 
debris from its contaminant(s). Because debris treated by one of these 
types of technologies is considered clean, such debris can then be 
disposed of in a subtitle D landfill. The immobilization technologies 
do not separate the debris from its contaminants, and therefore debris 
treated using an immobilization technology must be disposed of in a 
subtitle C landfill.\38\ The three immobilization technologies are 
macroencapsulation, microencapsulation, and sealing. Microencapsulation 
involves grinding up the debris and stabilizing it in a reagent. 
Sealing involves application of a coating material to the debris.
---------------------------------------------------------------------------

    \38\ The exception to this is characteristic debris. If 
characteristic debris which has been immobilized no longer displays 
the characteristic, it can be disposed in a Subtitle D landfill.
---------------------------------------------------------------------------

    Macroencapsulation, the standard which is at issue, involves 
placing the debris in an inert jacket of material (such as a steel 
drum) to prevent leaching. If the macroencapsulation standard is used, 
the performance standard, which states that the encapsulating material 
must be resistant to degradation by the debris and any contaminants on 
the debris, must be met before the debris can be land disposed.

B. What is an HDPE Vault?

    On June 15, 1995, three years after promulgation of the debris 
rule, Chemical Waste Management, Inc. (CWM) sent a letter to EPA in 
which they described their macroencapsulation process and asked whether 
it met the requirements of 40 CFR 268.45 (the letter and EPA's response 
are available in the docket for this ANPRM). CWM described their 
process as follows:

* * * a jacket of inert inorganic material is placed around hazardous 
debris, which is then placed in a high density polyethylene (HDPE) 
vault. An inert jacketing material (like cement) is then placed around 
the debris, the lid of the vault secured, and the vault is placed in a 
subtitle C landfill.
    We had not considered this type of technology when developing the 
macroencapsulation standard. However, we determined in our response 
letter to CWM that this process meets the definition of 
macroencapsulation for hazardous debris. We also stated in our response 
that merely placing hazardous debris in a container, unless the 
container is made of a noncorroding material such as stainless steel, 
does not meet performance standard for macroencapsulation. We think 
that use of the cement (or other stabilizing material) is critical to 
meeting the design and operating standard for macroencapsulation. 
Without the stabilizing agent, no guarantee exists that the 
encapsulating material would be resistant to the debris contaminants.

C. What Is the Issue With the HDPE Vaults?

    Because macroencapsulation is an immobilization technology, no 
removal or reduction of hazardous constituents is required. Therefore, 
debris placed into an HDPE vault could potentially have significant 
amounts of a contaminant.
    The technical support document for the debris rule did not include 
a description of the HDPE vault as this method did not come to our 
attention until after the August 19, 1992 rule was published. The June 
15, 1995 CWM letter did not include enough information that would have 
been required for a background document. Therefore, there has not been 
an extensive discussion about the effectiveness of the HDPE vaults. 
HDPE is a material that can be dissolved by even small amounts of 
solvents. The performance standard for macroencapsulation is clear in 
that the encapsulating material should be resistant to the debris and 
its contaminants. When hazardous debris contaminated with a significant 
amount of an organic solvent is placed in an HDPE vault, and if there 
is no stabilizing reagent, then theoretically the HDPE could dissolve 
from exposure to solvents. In this case, the performance standard for 
macroencapsulation has not been met. This is, in fact, improper 
treatment of a hazardous waste.
    As pointed out in the ETC petition, the debris proposed rule (57 FR 
958, January 9, 1992) originally stated that macroencapsulation was not 
appropriate for organic constituents. The technical support document 
for the proposed rule stated that macroencapsulation is not expected to 
be effective on organic compounds. The final debris rule may appear to 
some to be less restrictive than the proposal in that it does not 
contain the same prohibitive language. This is not the case. The table 
of alternative debris standards in the proposed rule was merely 
simplified for the final rule. ETC alleges in its petition that we did 
not place any contaminant restrictions on the macroencapsulation 
standard in the final rule as a result of the simplification of the 
table and that we meant to restrict macroencapsulation to inorganic 
debris only. This is also not true.
    The response to comment's document for the final rule addresses the 
change in the alternative treatment standards table. We stated that the 
final rule did not prohibit encapsulation of any specific debris type 
because the design and operating parameters and the performance 
standards were sufficient to ensure effective treatment of hazardous 
debris using encapsulation. Basically, we regard the performance 
standards as thorough enough to prevent inappropriate treatment. The 
technical support document for the final rule mentions that certain 
situations, such as using organic polymer encapsulants to encase 
organic solvents, would obviously not meet the performance standard. We 
therefore find no compelling reason to propose a revision to the 
current macroencapsulation standard in today's notice. However, the use 
of HDPE vaults to macroencapsulate debris was not considered in the 
final rulemaking, and we are taking this opportunity to open the issue 
for comment.

D. Request for Comment

    ETC is requesting that we amend the macroencapsulation standard to 
restrict it to ``metal-bearing hazardous waste'' only, and refer to the 
list of 43 listed and 8 characteristic wastes found in Appendix XI of 
40 CFR 268. We are taking comment on this ETC option. We are also 
soliciting data on macroencapsulated debris and the effectiveness of 
HDPE vaults and any other options you may have.
    We are also soliciting comment on restricting the use of the 
macroencapsulation standard for other types of wastes. Debris 
contaminated with a waste that has a specified method can be treated 
with one of the

[[Page 37952]]

alternative debris standards.\39\ We are today taking comments on 
whether this is appropriate.
---------------------------------------------------------------------------

    \39\ For ``debris-like'' material with a specified method, such 
as K109, the specified method must be used.
---------------------------------------------------------------------------

    We are also considering restricting the use of the 
macroencapsulation standard for certain types of debris. Some debris 
types lend themselves to other alternative treatment technologies. 
Cloth contaminated with a hazardous organic substance, for instance, 
could be more effectively treated by combustion. We suspect that the 
macroencapsulation standard is used because it is easier and less 
costly, but this may not foster the most effective method of treatment. 
We had hoped that the macroencapsulation standard would be used only 
when other, more effective methods of treatment could not. We are today 
taking comment on whether the macroencapsulation standard should be 
restricted to just inorganic debris contaminated with inorganic 
constituents that cannot be otherwise treated. This is more restrictive 
than the ETC option.

X. Should EPA Establish a Special Category for Incineration Ash?

A. What Are We Considering for Incineration Ash?

    Listed hazardous wastes carry the EPA hazardous waste codes of the 
as-generated waste from generation to ultimate land disposal. These 
waste codes are required to be placed on the LDR notification, which is 
the required LDR paperwork that accompanies the waste from the 
generator to the treatment, storage, or disposal facility and provides 
information about the waste so that the correct LDR treatment standards 
are met. In addition, some states require waste codes to be placed on 
the hazardous waste manifest, the RCRA tracking paperwork that 
accompanies hazardous wastes from generation to disposal. Facilities 
are also required to report information about their waste, including 
waste codes, to the Biennial Reporting System (BRS).
    Because several listed hazardous wastes may be treated together in 
an incinerator or other incineration device, a large number of waste 
codes could be required on the LDR notification, the manifest, and 
reported to the BRS with respect to the thermal treatment residues 
(i.e., the ash). We have heard from the regulated community that the 
tracking of multiple codes is burdensome and that a single waste code 
for incinerator ash would simplify paperwork and compliance monitoring. 
A single waste code could make it easier to track wastes on the 
manifest, especially in the event of a spill. A single waste code could 
also make completing the BRS much simpler, and could assist EPA in 
interpreting those BRS data. Therefore, we are considering establishing 
a waste code for incineration ash. It would likely be similar to the 
waste code established several years ago in the Third Third rule for 
multi-source leachate, F039 (55 FR 22619, June 1, 1990).

B. What Are the Approaches We Are Considering for Regulating 
Incineration Ash? \40\
---------------------------------------------------------------------------

    \40\ In the context of the Hazardous Waste Identification Rule 
(HWIR), the Chemical Manufacturers Association (CMA) suggested a 
different approach to regulating combustion ash. The CMA approach 
would exempt residues from the combustion of listed hazardous waste 
from the derived-from rule. The residues would then only be 
hazardous if they exhibit one of the hazardous waste characteristics 
of 40 CFR 261.3. We took comment on the CMA approach in the HWIR 
proposed rule (64 FR 63381, November 19, 1999). We will closely 
examine any comments we receive in response to that proposal, but we 
are not addressing nor soliciting additional comment on the CMA 
approach in this notice.
---------------------------------------------------------------------------

    Our initial thinking is that the incinerator ash waste code would 
encompass ash resulting from the incineration of more than one 
hazardous waste containing organic constituents, including organic 
toxicity wastes (D012-D043) and wastes with greater than 1% total 
organic carbon. The current definition of combustion, found in Table 1 
at 40 CFR 268.42, includes high temperature organic destruction 
technologies in units such as incinerators, boilers, or industrial 
furnaces operated in accordance with the requirements of 40 CFR 264-
265, Subparts O; or Part 266, Subpart H and potentially in other units 
operated in accordance with similar technical operating requirements 
(perhaps Subpart X). We solicit comments on whether an ash waste code 
should be for wastes that are incinerated, or whether ash from these 
other combustion units should thus be included. If we do include ash 
waste from such combustion devices, we solicit data on whether there 
are significant differences in the ash, and whether hazardous 
constituents partition into different types of residues, from these 
different incineration units. If differences do exist, should we 
regulate the ash from these different units accordingly? In addition, 
we solicit comments on whether the incineration ash waste code should 
be defined as the incineration of more than one hazardous waste 
containing organic constituents, including organic toxicity wastes 
(D012-D043) and wastes with greater than 1% total organic carbon, or 
whether it should be defined in some other way.
    If we were to establish a new waste code for incinerator ash, the 
ash would almost certainly be considered a new point of generation 
since the incineration unit will significantly alter the physical and 
chemical composition of, and the hazards associated with, the original 
waste. This is not to say that the toxicity of the original wastes has 
been completely removed. Rather, the composition and nature of the 
waste have changed to the point that the hazards posed by the 
incinerator ash are likely to be significantly different than the 
original waste, and the subsequent management and handling that would 
be environmentally warranted for incinerator ash could be significantly 
different from those for the original waste.
    Because hazardous constituents in incineration ash derive 
potentially from any of the hazardous wastes, our treatment standard 
should account for this possibility. One approach is to regulate all of 
the potential hazardous constituents that may be present. Subjecting 
the ash to the Universal Treatment Standards (UTS) would accomplish 
this goal. Under this approach, the ash would have to be evaluated for 
all UTS constituents, be treated if necessary to meet the UTS levels, 
and the resulting treatment residue would be placed in a hazardous 
waste (Subtitle C) landfill. Like the underlying philosophy for F039, 
however, it is unnecessary and wasteful to monitor constituents that 
are not present (55 FR 22620, June 1, 1990). Therefore, one 
modification to the approach outlined above would make the treater only 
responsible for meeting the treatment standards for those constituents 
specified in their permit waste analysis plan, which would be 
negotiated on a site-specific basis.

C. How Should the Dioxin Waste Codes Be Regulated?

    One approach would be to exclude ash derived from listed dioxin-
containing wastes F020-F023 and F026-F027 from any incineration ash 
code that we might develop. This would parallel the approach taken for 
F039, where dioxin-containing waste codes are not eligible for the more 
generic F039 classification. The ash would therefore continue to be 
classified and regulated as F020-F023 and F026-F027 wastes, the waste 
codes from which the ash is derived. Ash derived from soils 
contaminated with these waste codes would continue to be classified as 
F028. The reasoning behind continuing to

[[Page 37953]]

regulate the ash as a dioxin-containing waste code would be that these 
listed dioxin wastes are acutely hazardous and warrant special 
management standards (55 FR 22620, June 1, 1990). In addition, 
restrictions could be imposed that more explicitly prohibit mixing 
these dioxin wastes with other wastes to escape from more stringent 
management standards.
    Another approach would be to allow these dioxin-containing waste 
codes to be eligible for the incinerator ash waste code. In looking at 
whether this approach can be justified, we would consider the potential 
for dioxin-listed waste in the feed stream to cause elevated dioxin 
levels in the incinerator bottom ash and collected particulate matter. 
Although the Agency's incinerator regulations minimize stack emissions 
of dioxins (see 64 FR 52528, September 30, 1999), the regulations do 
not explicitly minimize dioxin levels in bottom ash. There are no ash 
burn-out requirements, for example. However, dioxins are not thermally 
stable and, as a practical matter, dioxins in the waste feed are easily 
destroyed in an incinerator's combustion chamber. Therefore, dioxin 
levels in incinerator bottom ash from burning dioxin-listed waste 
should be no higher than dioxin levels in the ash from burning other 
non-dioxin wastes. To further evaluate this issue, we will need data on 
dioxin concentrations in ash from burning both dioxin-containing waste 
codes and from burning other non-dioxin wastes.
    Similarly, our current incinerator regulations do not minimize 
dioxin levels in collected particulate matter. Because dioxins are so 
thermally unstable, it could be argued that waste particles entrained 
in the combustion gas are not likely to contain dioxins and that any 
dioxins found in the collected particulate matter result from post-
combustion formation, which is not related to dioxin levels in the 
waste feed.
    We are, therefore, interested in comment and data on whether the 
incineration of dioxin-containing waste cause either bottom ash or 
collected particulate matter to have higher levels of dioxin than the 
incineration of other non-dioxin wastes. Our decision on whether to 
propose to allow dioxin-containing waste codes to be eligible for an 
incinerator ash waste code (either with or without special management 
conditions) will be guided by the technical information we receive. We 
solicit comments on both approaches and on others that we should 
consider.

D. Should We Regulate Specific Constituents of Concern in the Ash?

    One potential problem with establishing a new waste code for 
incinerator ash is that it may require treatment of constituents that 
are not in the as-generated waste at levels of concern, but are either 
formed in the ash (e.g., dioxins) or concentrated in the ash (e.g., 
metals) during treatment. Currently, constituents that are not 
identified as UHCs in the untreated characteristic waste and that form 
during treatment only have to be treated if it is determined that there 
is a new LDR point of generation after the treatment occurs. We 
clarified two LDR point of generation questions in a recent technical 
amendment (64 FR 25411, May 11, 1999). There, we said:
    (1) For residuals that are the end product of a one-step treatment 
process or the end product of a treatment train, the treater has the 
obligation to ensure only that the original UHCs meet UTS standards and 
that the treatment residuals are not themselves characteristic. If a 
treatment residual in this scenario does not meet the treatment 
standards for the original characteristic (i.e., when treatment is 
ineffective or incomplete) and requires further treatment, EPA does not 
consider the treatment residue to be newly generated for LDR purposes. 
Such a treatment residue, however, cannot be land disposed until it 
meets the treatment standard applicable to the original waste. This 
situation would normally involve retreating the waste residuals on-
site. Any UHCs added or created by the treatment process are not 
required to be treated because there is no new point of generation for 
LDR purposes. However, as noted above, if the treatment residuals are 
themselves characteristic due to a new property (for example, an 
incinerator ash resulting from the incineration of several listed 
wastes is now only characteristic for D008 lead), then the treater must 
make a new determination of the UHCs present--either through knowledge 
or additional testing. This is the same obligation that attaches to any 
generator of a hazardous waste.
    (2) For treatment residuals that appear only at intermediate steps 
of a treatment train, there is no obligation to determine UHCs or to 
determine whether the residual is itself characteristic. Intermediate-
step treatment residuals are not newly generated hazardous wastes for 
LDR purposes. Thus, even when an intermediate treatment residual is 
sent off-site for further treatment (such as incinerator ash going 
offsite for stabilization and land filling), our current regulations at 
40 CFR 268.7(b)(5) require only that the UHCs identified at the LDR 
point of generation be identified. There is no such requirement for any 
new UHCs that may be added or created during the preceding steps of the 
treatment process.
    As indicated above, if we develop a separate waste code for 
incinerator ash and if the ash is considered a new LDR point of 
generation, full waste characterization of the ash would have to take 
place. Some constituents that were not UHCs in the characteristic 
wastes originally going into the incinerator could now be UHCs, 
particularly metals that are concentrated in the ash or, potentially, 
trace levels of dioxins and furans. We solicit comment and data on the 
concentration of metals or dioxins/furans in incineration ash and on 
the effect of establishing a waste code for incinerator ash. If we do 
not receive data, we may need to presume that these constituents are 
present in the ash at levels above UTS. In addition, we request data on 
levels of dioxin and furan leaching from incinerator ash, both 
untreated and after stabilization. These data will be highly important 
for our deliberations on whether to establish a separate waste code for 
incineration ash and, if so, what the treatment standard should be.

E. Would the Incinerator Ash Waste Code Be Optional?

    Our initial thinking is that the original waste codes would not 
apply to incinerator ash (i.e., no waste code carry through). This is 
mainly because categorizing ash according to the original waste codes 
may, in some cases, result in less treatment of waste constituents than 
if the waste were categorized as a new waste code for incineration ash. 
For example, ash from the incineration of listed organic wastes may 
contain low levels of metals that would not be treated under the 
treatment standard for the original waste but would be found at higher 
levels in the ash due to concentration. We solicit comments on this 
issue and, in particular, whether the incinerator ash code should 
always apply, or whether the original waste codes should apply in some 
circumstances (including on a case-by-case basis). We would also like 
comments on how this second option would affect the consistency and 
accuracy of the BRS database.

F. Are There Ways To Reduce the Analytical Burden?

    We are soliciting comments on approaches that could be used to 
limit the number of constituents that would

[[Page 37954]]

require testing and analysis if a new waste code for incinerator ash 
were established. For example, we already have provided regulatory 
relief for organic constituents in listed waste that have been 
combusted when testing and analysis indicates they are below detection 
limits (40 CFR 268.40(d)). The provision allows these wastes to meet 
concentrations that are one order of magnitude greater than the LDR 
treatment standard. Under the ash waste code approach, would it be 
environmentally protective to allow testing and analysis of the other 
organic constituents to serve as surrogates for nondetectable 
constituents? If so, which ones? We solicit data on this issue.
    One variation on this approach would apply a reduced analytical 
scheme only to incineration units that treat many waste codes. Rather 
than require analysis of the hundreds of constituents that could 
potentially be present, we could instead develop a list of surrogate 
constituents to regulate. We note that some previous efforts along this 
line have shown that selecting appropriate surrogates is a very 
difficult technical challenge. If we could overcome this challenge, 
then we expect that this list would most likely include the most 
difficult to combust organic constituents, all metals, and some 
thermally labile constituents to confirm performance of the unit. 
Analysis of these surrogate constituents would demonstrate adequate 
treatment of all incoming wastes of concern. These types of treatment 
data would also show whether metals have concentrated in the ash, and 
what types of treatment (e.g., stabilization) would be appropriate 
before land disposal. We are requesting comment on this issue, 
including data and potential constituents for this surrogate list.

G. Request for Comment

    We are requesting comments and data on the following ash waste code 
topics.
     We solicit general comments on whether we should establish 
a waste code for incineration ash.
     We solicit comments on whether to exclude ash derived 
exclusively from listed dioxin-containing wastes F020-F023 and F026-
F027 from the incineration ash code.
     We solicit data on whether there are significant 
differences in the ash from different combustion units, and whether 
hazardous constituents partition into different types of residues, from 
these different units. If differences do exist, should we regulate the 
ash from these different units accordingly?
     We solicit comments on whether the incineration ash waste 
code should be defined as the incineration of more than one hazardous 
waste containing organic constituents, including organic toxicity 
wastes (D012-D043) and wastes with greater than 1% total organic 
carbon, or whether it should be defined in some other way.
     We solicit comment on whether the treater should only be 
responsible for meeting the treatment standards for those constituents 
specified in their permit waste analysis plan, which would be 
negotiated on a site-specific basis.
     We solicit comments on whether the incinerator ash code 
should always apply, or whether the original waste codes should apply 
in some circumstances (including on a case-by-case basis). We would 
also like comments on how this second option would affect the 
consistency and accuracy of the BRS database.
     We solicit comments on approaches that could be used to 
limit the number of constituents that would require testing and 
analysis if a new waste code were established.
     We solicit comment and data on whether under the ash waste 
code approach, would it be environmentally protective to allow testing 
and analysis of the other organic constituents to serve as surrogates 
for nondetectable constituents? If so, which ones?

XI. Should EPA Establish Tailored Treatment Standards for Mixed 
Wastes? \41\
---------------------------------------------------------------------------

    \41\ Note that EPA recently published a proposed rule on the 
storage, treatment, transportation, and disposal of mixed waste 
proposed rule. See 64 FR 63464, November 19, 1999.
---------------------------------------------------------------------------

A. What Are Mixed Wastes?

    Mixed wastes are those wastes that satisfy the definition of 
radioactive waste subject to the Atomic Energy Act (AEA) and that also 
contain listed or characteristic hazardous wastes. On July 3, 1986, we 
determined that the hazardous portions of mixed wastes are subject to 
RCRA regulation (51 FR 4504). This situation creates a dual and 
complementary regulatory framework between RCRA and the AEA.
    Because the hazardous portions of mixed waste are subject to RCRA, 
the land disposal restrictions apply. The hazardous portions must 
therefore meet the appropriate LDR treatment standards before land 
disposal.

B. What Are the Issues Associated With Regulating Mixed Wastes?

    Potential difficulties exist when applying the LDRs to mixed waste. 
They relate primarily to analytical problems and concerns about worker 
exposure to radiation when treating or testing mixed waste.
    The Department of Energy (DOE) has raised these types of issues at 
several junctures, including the July 1998 LDR roundtable and in 
comments on several LDR rules, the proposed Hazardous Waste 
Identification Rule (HWIR), and the Mixed Waste Disposal Rule. With 
respect to compliance monitoring, DOE asserts that the difficulty and 
costs associated with sampling and analysis increase as the constituent 
concentration levels that need to be detected are lowered and as 
radiological exposure increases. Some of the analytical difficulties 
and costs associated with sampling and analysis include:
     Sample collection--The sample volumes specified in ``Test 
Methods for Hazardous Wastes'' (SW-846) may not be obtainable for high 
level mixed waste (i.e., spent fuel from commercial nuclear power 
plants and defense high-level waste from the production of weapons) 
because the sample volumes would result in excessive radiation exposure 
to personnel collecting the samples and conducting the analyses.
     Storage--Special sample storage containers must be used to 
address radiological hazards. For example, refrigeration of samples 
cannot be achieved in all instances because samples must be placed in 
pre-designed lead-lined shipment containers that do not lend themselves 
to cooling.
     Interference due to the radiological matrix--Some 
radionuclides interfere with the detection of hazardous constituents. 
For example, when a mixed waste sample containing plutonium is 
volatilized and analyzed as an emission spectra, the plutonium peak 
obscures peaks that indicate the presence of hazardous metals. DOE 
asserts that this is a common analytical problem for mixed waste 
containing transuranic elements (atomic number greater than 92).
     Manipulating high level mixed waste--Analysis must be 
conducted in hot cell laboratories where the waste is remotely handled. 
The use of manipulators is time consuming and, as a result, it is often 
difficult to conform to the holding times specified in SW-846.
     Limited analytical capacity and capability--Laboratory 
capacity as well as capability for handling mixed waste is limited. The 
shortage in capacity is most acute for higher level wastes. In 
addition, when equipment becomes ``hot'' due to exposure to 
radionuclides in samples, it must be dedicated to analysis of 
radioactive materials only.

[[Page 37955]]

     Waste disposal--The costs associated with cleanup and 
waste disposal after analysis are substantial. For example, protective 
clothing and equipment used during sampling activities must be handled 
as low level radioactive waste.
     Exposure--The policy under DOE's health and safety program 
is to maintain exposures As Low As Reasonably Achievable (ALARA). 
Worker exposure during collection, handling, and transport of samples 
as well as during analysis needs to be minimized, which sometimes does 
not occur when meeting RCRA compliance obligations.

C. How Has EPA Responded to the Issues Associated With Regulating Mixed 
Waste?

    Recognizing the public's concern over potential radiation exposure 
from mixed waste testing, we developed, in close coordination with the 
Nuclear Regulatory Commission (NRC), a mixed waste testing guidance 
titled ``Joint NRC/EPA Guidance on Testing Requirements for Mixed 
Radioactive and Hazardous Waste.'' \42\ The primary purpose of this 
guidance document is to help NRC licensees and others characterize 
their mixed waste in accordance with RCRA regulations while keeping 
radiation exposure as low as reasonably achievable (ALARA). The 
guidance emphasizes flexibility in the RCRA testing requirements so 
that the ALARA concept can be incorporated. For example, the guidance 
emphasizes and encourages the use of process knowledge whenever 
possible to avoid unnecessary exposure to radiation. The guidance 
describes methods by which individuals who sample and analyze mixed 
waste may reduce their occupational radiation exposure, for example by 
keeping RCRA frequency of testing to a minimum by avoiding duplicative 
testing.
---------------------------------------------------------------------------

    \42\ This guidance document can be found in the docket for 
today's notice.
---------------------------------------------------------------------------

    In the LDR Third Third final rule (55 FR 22552, June 1, 1990), we 
relied upon data and information submitted by DOE to tailor several 
treatment standards for certain mixed wastes. These data indicated that 
for certain high-level wastes that also display hazardous metal 
characteristics the most appropriate treatment standard is 
vitrification. The DOE vitrification process reduces the mobility of 
both the hazardous and radioactive components of the waste. We 
therefore adopted vitrification as the treatment standard for these 
high level mixed wastes. Because the treatment standard is expressed as 
a specified method of treatment, facilities need not demonstrate 
compliance by routinely measuring concentration levels, thus minimizing 
worker contact with the high level mixed waste.
    Another treatment standard was established for characteristic 
radioactive lead solids. It requires radioactive wastes such as lead 
shielding, pigs, and other elemental forms of lead to be 
macroencapsulated. By requiring a surface coating or a jacket of inert 
inorganic materials, this treatment standard substantially reduces 
surface exposure to potential leaching media. We established other 
tailored treatment standards for mixed wastes containing elemental 
mercury and for mercury contaminated radioactive hydraulic oil. All of 
these treatment standards reduce workers' exposure to radioactivity 
because there is no requirement to measure compliance with treatment 
standard levels.
    In addition, in a recent ANPRM (64 FR 28949, May 28, 1999) we 
solicited comment on establishing a tailored treatment standard for one 
type of radioactive mixed waste containing mercury. As explained in 
that ANPRM, under current regulations, no separate treatment category 
exists for high mercury wastes that also contain radioactive materials. 
Therefore, the current regulations may result in equipment 
contamination by radiation to recover radioactive mercury that must 
then be further treated and disposed because it is no longer useful. In 
the mercury ANPRM, we specifically requested comments on eliminating 
the retorting treatment standard for mixed mercury wastes, and on 
allowing the use of alternative technologies, with the residuals having 
to comply with a numerical limit. Please refer to the mercury ANPRM for 
additional discussion of this issue and instructions for viewing 
background materials.

D. What Is EPA Considering in This ANPRM?

    The threat of radiological exposure cannot be completely eliminated 
because mixed wastes will require handling for purposes of treatment 
and compliance monitoring before disposal. Therefore, we encourage NRC 
licensees and others to use the ``Joint NRC/EPA Guidance on Testing 
Requirements for Mixed Radioactive and Hazardous Waste'' to keep the 
worker exposure to radiation to a minimum. Precautions to minimize 
exposure from waste analysis should be identified and incorporated into 
site-specific waste analyses plans, which are overseen by state and 
regional authorities under the Federal Facilities Compliance Act.
    We remain committed to reducing radiological exposure as much as 
possible. Therefore, we wish to explore if additional opportunities 
exist for mixed radioactive wastes to have a specified method of 
treatment rather than concentration limits as the treatment standard. 
For instance, high-level nonwastewaters that must be remotely handled 
may be good candidates for a specified treatment method such as 
vitrification, if it is designed to trap air and water emissions and to 
create a stable glass. Similarly, carbon adsorption may be appropriate 
for certain mixed radioactive wastewaters such as high molecular weight 
organics.

E. Request for Comment

    We are soliciting comments and data on the treatability of mixed 
waste and on the analytical problems associated with measuring 
compliance with concentration levels. In particular, we are interested 
in whether there are other treatment methods that should be tailored to 
specific mixed wastes, like the ones established in the Third Third 
final rule, particularly because such standards eliminate the need for 
compliance monitoring with its associated dangers of worker exposure to 
radiation.
    Commenters should submit data on the technology and its operating 
parameters. It is important that the data submitted is complete (i.e., 
a complete description of the technology, its operating parameters, and 
any chemical reactions that take place). In addition, the commenter 
should submit data on the properties of the mixed waste for which the 
tailored treatment method is requested. This should also include 
detailed information on whether and how the presence of radionuclides 
affects the performance of the treatment technology. Once these data 
are evaluated, we may propose to establish tailored treatment standards 
that are expressed as required methods of treatment for certain mixed 
radioactive wastes.

XII. Is EPA Addressing LDR Paperwork Burden in This ANPRM?

    One of the issues raised during the LDR roundtable was whether the 
paperwork burden could be reduced in the LDR program. Participants 
suggested that we allow electronic recordkeeping and reporting, and 
that we further reduce the requirements for generators, treaters, and 
disposers. We agree that these are good ideas. They are not, however, 
discussed in this ANPRM, but they are included in a separate EPA Notice 
of Data Availability (NODA) that

[[Page 37956]]

addresses burden reduction. See 64 FR 32859, June 18, 1999.
    The NODA contains ideas to reduce the reporting and recordkeeping 
paperwork burden throughout OSW's regulatory programs, including the 
LDR program. Currently, the LDR paperwork requirements account for 
nearly one-third of the burden for the RCRA program. Substantial 
reduction has already occurred, particularly as a result of the May 12, 
1997 LDR rule. Before this rule, generators and treaters that sent 
their hazardous waste off-site had to send a notification with each 
shipment of waste informing treaters and disposers of the composition 
of the waste stream. This rule changed these requirements so that the 
notification need only be sent with the initial waste shipment, so long 
as the waste and the receiving facility remained unchanged. This 
paperwork change resulted in a savings of 1,630,000 burden hours 
annually.
    The NODA describes a number of other possible changes to reduce the 
LDR burden. These changes include eliminating 268.7(a)(1) Generator 
Waste Determinations; eliminating 268.7(b)(6) Recycler Notifications 
and Certifications; eliminating 268.7(d) Hazardous Debris 
Notifications; eliminating 268.9(a) Characteristic Waste 
Determinations; and streamlining 268.9(d) Notification Procedures. See 
the NODA for further information on these possible changes to reduce 
the LDR paperwork burden.
    The NODA was the first step in developing a final regulation for 
reducing reporting and recordkeeping burden for the RCRA program. We 
plan to issue a proposed rule this year to follow-up on some of the 
items in the NODA.

XIII. What Issues Are Not Addressed in This ANPRM?

    In addition to the nine main issues described in this ANPRM, a 
number of other issues were brought up by participants at the 1998 LDR 
roundtable. Due to our own prioritization and resource constraints, we 
were not able to investigate these issues in depth. We are, however, 
interested in new comments from you on any of these issues.
    1. Dilution prohibition: In the 1996 Phase III LDR rule (61 FR 
15566, April 8, 1996), we promulgated a list of inorganic wastes that 
are not allowed to be treated by combustion because of the low presence 
of organics in these wastes. We may need to investigate which inorganic 
wastes are currently combusted, and determine whether to expand the 
list, if it is currently too restrictive. Also, we may need to 
investigate current information available to EPA on the issue of wastes 
that go into fuel blending and the issue of waste code carry-through.
    2. Generator Knowledge: We could investigate whether there is too 
much or too little reliance on generator knowledge to determine which 
underlying hazardous constituents in characteristic wastes need to be 
treated.
    3. Plain Language: We could simplify the LDRs by rewriting them in 
plain language.
    4. Refractory Bricks: We could evaluate whether refractory bricks 
from incinerators should still be subject to treatment standards based 
on listed waste codes.
    5. Generator Guidance: We could clarify through guidance how 
generators can more easily determine when LDRs apply and which 
treatment standards are applicable.

XIV. Administrative Requirements

A. Regulatory Flexibility

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the APA or any other 
statute unless the agency certifies that the rule will not have a 
significant economic impact on a substantial number of small entities. 
Small entities include small businesses, small organizations, and small 
governmental jurisdictions. This ANPRM will not have a significant 
impact on a substantial number of small entities because it does not 
create any new requirements. Therefore, EPA provides the following 
certification under the Regulatory Flexibility Act, as amended by the 
Small Business Regulatory Enforcement Fairness Act: Pursuant to the 
provision at 5 U.S.C. 605(b), I certify that this action will not have 
a significant economic impact on a substantial number of small 
entities. However, there is the potential for future actions related to 
this ANPRM to have a significant economic impact on a substantial 
number of small entities. Therefore, the Agency will examine whether 
the Regulatory Flexibility Act applies in the preparation of any future 
rulemakings related to this ANPRM.

B. Executive Order 13045

    Protection of Children from Environmental Health Risks and Safety 
Risks (62 FR 19885, April 23, 1997), applies to any rule that: (1) Is 
determined to be ``economically significant'' as defined under E.O. 
12866; and (2) concerns an environmental health or safety risk that EPA 
has reason to believe may have a disproportionate effect on children. 
If the regulatory action meets both criteria, the Agency must evaluate 
the environmental health or safety effects of the planned rule on 
children, and explain why the planned regulation is preferable to other 
potentially effective and reasonably feasible alternatives considered 
by the Agency.
    This ANPRM is not subject to E.O. 13045 because it is does not, at 
this point, involve decisions intended to mitigate environmental health 
or safety risks. Of course, as the information in response to this 
ANPRM is evaluated, we will continue to examine whether E.O. 13045 
applies.

List of Subjects in 40 CFR Part 268

    Hazardous waste, Reporting and recordkeeping requirements.

    Dated: June 12, 2000.
Carol M. Browner,
Administrator.
[FR Doc. 00-15392 Filed 6-16-00; 8:45 am]
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