[Federal Register Volume 64, Number 164 (Wednesday, August 25, 1999)]
[Proposed Rules]
[Pages 46476-46539]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-20753]



[[Page 46475]]

_______________________________________________________________________

Part II





Environmental Protection Agency





_______________________________________________________________________



40 CFR Parts 148, 261, 264, 265, 268, 271, and 302



Hazardous Waste Management System; Identification and Listing of 
Hazardous Waste; Chlorinated Aliphatics Production Wastes; Land 
Disposal Restrictions for Newly Identified Wastes; and CERCLA Hazardous 
Substance Designation and Reportable Quantities; Proposed Rule

  Federal Register / Vol. 64, No. 164 / Wednesday, August 25, 1999 / 
Proposed Rules  

[[Page 46476]]



ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 148, 261, 264, 265, 268, 271, and 302

[SWH-FRL-6413-4]
RIN 2050-AD85


Hazardous Waste Management System; Identification and Listing of 
Hazardous Waste; Chlorinated Aliphatics Production Wastes; Land 
Disposal Restrictions for Newly Identified Wastes; and CERCLA Hazardous 
Substance Designation and Reportable Quantities

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: The EPA is proposing to list three of six wastes from the 
chlorinated aliphatics industry as hazardous wastes under the Resource 
Conservation and Recovery Act (RCRA), which directs EPA to determine 
whether certain wastes from the chlorinated aliphatics industry present 
a hazard to human health or the environment. The effect of listing 
these three wastes will be to subject them to stringent management and 
treatment standards under RCRA and to subject them to emergency 
notification requirements for releases of hazardous substances to the 
environment. EPA is proposing a contingent-management listing approach 
for one of these wastes, and as one of two options for another of these 
wastes, such that waste generators will have the option of their waste 
not being listed if it is sent to a specific type of management 
facility.

DATES: EPA will accept public comments on this proposed rule until 
November 23, 1999. Comments postmarked after this date will be marked 
``late'' and may not be considered. Any person may request a public 
hearing on this proposal by filing a request by September 8, 1999.

ADDRESSES: If you wish to comment on this proposed rule, you must send 
an original and two copies of the comments referencing docket number F-
1999-CALP-FFFFF to: RCRA Docket Information Center, Office of Solid 
Waste (5305G), U.S. Environmental Protection Agency Headquarters (EPA, 
HQ), 401 M Street, SW, Washington, D.C. 20460. Hand deliveries of 
comments should be made to the Arlington, VA, address listed in the 
fourth paragraph of SUPPLEMENTARY INFORMATION. You also may submit 
comments electronically by sending electronic mail through the Internet 
to: [email protected]. See the beginning of SUPPLEMENTARY 
INFORMATION for instructions on electronic submission.
    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. EPA, 401 M Street, SW, Washington, D.C. 
20460. See the beginning of SUPPLEMENTARY INFORMATION for information 
on viewing public comments and supporting materials.
    Address requests for a hearing to Mr. David Bussard at: Office of 
Solid Waste, Hazardous Waste Identification Division (5304W), U.S. 
Environmental Protection Agency, 401 M Street, SW, Washington, D.C. 
20460, (703) 308-8880.

FOR FURTHER INFORMATION CONTACT: For general information, contact the 
RCRA Hotline at (800) 424-9346 or TDD (800) 553-7672 (hearing 
impaired). In the Washington, D.C., metropolitan area, call (703) 412-
9810 or TDD (703) 412-3323. For information on specific aspects of the 
rule, contact Ross Elliott of the Office of Solid Waste (5304W), U.S. 
Environmental Protection Agency, 401 M Street, SW, Washington, D.C. 
20460. [E-mail addresses and telephone numbers: 
[email protected], (703) 308-8748.]

SUPPLEMENTARY INFORMATION: You should identify comments in electronic 
format with the docket number F-1999-CALP-FFFFF. You must submit all 
electronic comments as an ASCII (text) file, avoiding the use of 
special characters and any form 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 comments on 
diskettes is not mandatory, nor will it result in any advantage or 
disadvantage to any commenter. Supporting documents in the docket for 
this Notice are also available in electronic format on the Internet. 
Follow these instructions to access these documents.

WWW: http://www.epa.gov/epaoswer/hazwaste/id
FTP: ftp.epa/gov
Login: anonymous
Password: your Internet address
Files are located in /pub/gopher/OSWRCRA.

    EPA will keep the official record for this action in paper form. 
Accordingly, we will transfer all comments received electronically into 
paper form and place them in the official record, which will also 
include all comments submitted directly in writing. The official record 
is the paper record maintained at the address in ADDRESSES at the 
beginning of this document.
    EPA responses to comments, whether the comments are written or 
electronic, will be in a notice in the Federal Register or in a 
response to comments document placed in the official record for this 
rulemaking. We will not immediately reply to commenters electronically 
other than to seek clarification of electronic comments that may be 
garbled in transmission or during conversion to paper form, as 
discussed above.
    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 
a.m. to 4 p.m., Monday through Friday, excluding federal holidays. To 
review docket materials, we recommend that you make an appointment by 
calling (703) 603-9230. You may copy a maximum of 100 pages from any 
regulatory docket at no charge. Additional copies cost $0.15/page. For 
information on accessing paper and/or electronic copies of the 
document, see the first paragraph of the SUPPLEMENTARY INFORMATION 
section.

Customer Service

How Can I Influence EPA's Thinking on This Proposed Rule?

    In developing this proposal, we tried to address the concerns of 
all our stakeholders. Your comments will help us improve this rule. We 
invite you to provide different views on options we propose, new 
approaches we haven't considered, new data, how this rule may affect 
you, or other relevant information. We welcome your views on all 
aspects of this proposed rule, but we request comments in particular on 
the items indicated at the end of each section. Your comments will be 
most effective if you follow the suggestions below:
     Explain your views as clearly as possible and provide a 
summary of the reasoning you used to arrive at your

[[Page 46477]]

conclusions, as well as examples to illustrate your views, where 
possible.
     Provide solid technical and cost data to support your 
views.
     If you estimate potential costs, explain how you arrived 
at your estimate.
     Tell us which parts you support, as well as those with 
which you disagree.
     Offer specific alternatives.
     Reference your comments to specific sections of the 
proposal, such as the sections or page numbers of the preamble, or the 
regulatory citations.
     Remember that your comments must be submitted by the 
deadline in this notice.
     Include the name, date, and docket number with your 
comments.

Contents of This Proposed Rule

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

I. Overview

A. Who Potentially Will Be Affected by This Proposed Rule?
B. Why Does This Rule Read Differently From Other Listing Rules?
C. What Are the Statutory Authorities for This Rule?

II. Background

A. Schedule Suit
B. Existing Chlorinated Aliphatics Listings

III. Today's Action

A. Summary of Today's Action
    1. Scope of the Listing Determination
    2. Summary of the Proposed Listing Determinations
    3. Summary of the Remainder of This Preamble
B. Description of the Industry
C. Overview of EPA's Information Collection Activities
    1. Field Investigations and Sampling
    2. RCRA Section 3007 Survey
D. What Are the Risks Associated With Management of Wastewaters and 
Wastewater Treatment Sludges From the Production of Chlorinated 
Aliphatic Chemicals?
    1. What Are the Risks for Potential Human Receptors?
    2. What Are the Potential Risks for Ecological Receptors?
    3. Did EPA Conduct a Peer Review of the Risk Assessment?
E. Waste-Specific Listing Determination Rationales
    1. Chlorinated Aliphatics Wastewaters
    2. EDC/VCM Wastewater Treatment Sludges
    3. VCM-A Wastewater Treatment Sludges
    4. Methyl Chloride Wastewater Treatment Sludges
    5. Allyl Chloride Wastewater Treatment Sludges
F. Constituents Proposed for Addition to Appendix VIII to 40 CFR 
Part 261

IV. Economic Analysis

A. What Is the Purpose of the Economic Analysis?
B. How May the Public Participate in the Economic Analysis?
C. How Are Chlorinated Aliphatic Chemicals Used in the Economy?
D. Where Are CAHCs Manufactured in the United States?
E. Have CAHCs Been Produced Historically in Other Locations in the 
United States?
F. What Are the Estimated Potential Industry Costs of This Listing?

V. Proposed Treatment Standards Under RCRA's Land Disposal Restrictions

A. What Are EPA's Land Disposal Restrictions (LDRs)?
B. How Does EPA Develop LDR Treatment Standards?
C. What Kind of Treatment Standards Are Proposed?
D. Other LDR-Related Provisions
E. What Standards Are Proposed for K173?
F. What Standards Are Proposed for K174?
G. What Standards Are Proposed for K175?
H. What Other Land Disposal Restrictions Aspects Are There to the 
Proposal?
I. Is There Treatment Capacity for the Proposed Wastes?

VI. Compliance Dates

A. Notification
B. Interim Status and Permitted Facilities

VII. State Authority

A. Applicability of Rule in Authorized States
B. Effect on State Authorizations

VIII. Designation of Chlorinated Aliphatic Wastes (K173, K174 and K175) 
Under the Comprehensive Environmental Response, Compensation, and 
Liability Act (CERCLA)

A. What Is the Relationship Between RCRA and CERCLA?
B. Is EPA Proposing To Add Chlorinated Aliphatic Wastes to CERCLA?
C. How Does EPA Determine Reportable Quantities?
D. When Do I Need to Report a Release of K173, K174 or K175 Under 
CERCLA?
E. What if I Know the Concentration of the Constituents in My Waste?
F. How Did EPA Determine the RQs for K173, K174 and K175 and Their 
Hazardous Constituents?
G. How Do I Report a Release?
H. What Is the Statutory Authority for This Program?
I. How Can I Influence EPA's Thinking on Regulating K173, K174 and 
K175 Under CERCLA?

IX. Administrative Assessments

A. Executive Order 12866
B. Regulatory Flexibility Act
C. Paperwork Reduction Act
D. Unfunded Mandates Reform Act
E. Executive Order 12875: Enhancing the Intergovernmental 
Partnership
F. Executive Order 13084: Consultation and Coordination With Indian 
Tribal Governments
G. Executive Order 13045: Protection of Children From Environmental 
Risks and Safety Risks
H. National Technology Transfer and Advancement Act of 1995
I. Executive Order 12898: Environmental Justice

I. Overview

A. Who Potentially Will Be Affected by This Proposed Rule?

    Beginning January 1, 1999 all documents related to USEPA's 
regulatory, compliance and enforcement activities including rules, 
policies, interpretive guidance, and site-specific determinations with 
broad application, should properly identify the regulated entities, 
including descriptions that correspond to the applicable SIC codes or 
NAICS codes (source: 09 October 1998 USEPA memo from Peter D. 
Robertson, Acting Deputy Administrator of USEPA). Today's action, if 
finalized, could potentially affect those who handle the wastes that 
EPA is proposing to add to the Agency's list of hazardous wastes under 
the RCRA program. This action also may affect entities that may need to 
respond to releases of these wastes as CERCLA hazardous substances. 
These potentially-affected entities are described in the Economics 
Background Document placed in the docket in support of today's proposed 
rule; a summary is shown in the table below.

    Summary of Facilities Potentially Affected by the USEPA's 1999 Chlorinated Aliphatics Manufacturing Waste
                          Listing Proposal According to Applicable SIC and NAICS Codes
----------------------------------------------------------------------------------------------------------------
                                                                                      Number of
                                   Parent                                                U.S.         Parent
             Item                 company             Industry sector name             relevant   company  NAICS
                                  SIC code                                            CAHC mfg.        code
                                                                                     facilities*   equivalent**
----------------------------------------------------------------------------------------------------------------
1.............................         1311  Mining: Crude petroleum and natural               3          211111
                                              gas.
2.............................         1400  Mining: Nonmetallic minerals, except              2          212300
                                              fuels.

[[Page 46478]]

 
3.............................         2295  Manufacturing: Coated fabrics, not                1           31332
                                              rubberized.
4.............................         2800  Manufacturing: Chemicals & allied                 3          325000
                                              products.
5.............................         2810  Manufacturing: Chemicals & allied                 1          325000
                                              products.
6.............................         2812  Manufacturing: Alkalies & chlorine                1          325181
                                              manufacture.
7.............................         2821  Manufacturing: Plastics materials &               8          325211
                                              resins.
8.............................         2851  Manufacturing: Paints & allied                    1           32551
                                              products.
9.............................         2869  Manufacturing: Industrial organic                 1           32511
                                              chemicals, nec.
10............................         2911  Manufacturing: Petroleum refining.....            1           32411
11............................         3600  Manufacturing: Electronic & other                 1          335000
                                              electric equipment.
                                                                                    -------------
                                                 Total Applicable Facilities.......           23
----------------------------------------------------------------------------------------------------------------
*The number of relevant facilities is based on the (a) type of CAHC products manufactured, (b) types of wastes
  generated, and (c) baseline waste management practices, in relation to the terms and conditions of the
  proposed listing options. However, all CAHC manufacturing facilities in each industrial sector code may not be
  affected by the proposed listing options.
**OSW-EMRAD derived the NAICS code equivalents above from the SIC-to-NAICS conversion tables provided by the US
  Department of Commerce, Bureau of the Census, at the following website: http://www.census.gov/epcd/www/
naicstab.htm. There is no direct match in the SIC-NAICS conversion tables for SIC codes 1400, 2800, 2810, and
  3600, so a generalized six-digit NAICS code is provided above for these four cases.

    The list of potentially affected entities in the above table may 
not be exhaustive. Our aim is to provide a guide for readers regarding 
entities likely to be regulated by this action. This table lists those 
entities that EPA is aware potentially could be affected by this 
action. However, this action may affect other entities not listed in 
the table. To determine whether your facility is regulated by this 
action, you should examine 40 CFR 260 and 261 carefully in concert with 
the proposed rules amending RCRA that are found at the end of this 
Federal Register notice. If you have questions regarding the 
applicability of this action to a particular entity, consult the person 
listed in the preceding section entitled FOR FURTHER INFORMATION 
CONTACT.

B. Why Does This Rule Read Differently From Other Listing Rules?

    Today's proposed listing determination preamble and regulations are 
written in ``readable regulations'' format. The authors tried to use 
active rather than passive voice, plain language, a question-and-answer 
format, the pronouns ``we'' for EPA and ``you'' for the owner/
generator, and other techniques to make the information in today's rule 
easier to read and understand. This new format is part of the Agency's 
efforts at regulatory reinvention, and it makes today's rule read 
differently from other listing rules. The Agency believes that this new 
format will increase readers' abilities to understand the regulations, 
which should then increase compliance, make enforcement easier, and 
foster better relationships between EPA and the regulated community.

C. What Are the Statutory Authorities for This Rule?

    These regulations are being proposed under the authority of 
Sections 2002(a), 3001(b), 3001(e)(2) and 3007(a) of the Solid Waste 
Disposal Act, 42 U.S.C. 6912(a), 6921(b) and (e)(2), and 6927(a) as 
amended several times, most importantly by the Hazardous and Solid 
Waste Amendments of 1984 (HSWA). These statutes commonly are referred 
to as the Resource Conservation and Recovery Act (RCRA), and are 
codified at Volume 42 of the United States Code (U.S.C.), Sections 6901 
to 6992(k) (42 U.S.C. 6901-6992(k)).
    Section 102(a) of the Comprehensive Environmental Response, 
Compensation, and Liability Act of 1980 (CERCLA), 42 U.S.C. 9602(a) is 
the authority under which the CERCLA aspects of this rule are being 
proposed.

II. Background

A. Schedule Suit

    In 1989, the Environmental Defense Fund (EDF) sued the 
Environmental Protection Agency (EPA), in part for failing to meet the 
statutory deadlines of Section 3001(e)(2) of RCRA (EDF vs. Browner; 
Civ. No. 89-0598 D.D.C.). To resolve most of the issues in the case, 
EDF and EPA entered into a consent decree, which has been amended 
several times to revise dates. The consent decree sets out deadlines 
for promulgating certain RCRA rules and for completing certain studies 
and reports. Paragraph 1. m. of the consent decree obliges EPA to 
propose a hazardous waste listing determination for wastewaters and 
wastewater treatment sludges generated from the production of specified 
chlorinated aliphatic chemicals. The wastewater and wastewater 
treatment sludges subject to the consent decree are those from the 
production of chlorinated aliphatics for which other process wastes 
already have been designated as hazardous waste F024 in 40 CFR 261.31. 
According to the consent decree, EPA must propose listing 
determinations by July 30, 1999 and promulgate final listing 
determinations on or before September 30, 2000. Today EPA is proposing 
listing determinations for these wastes in accordance with the consent 
decree.

B. Existing Chlorinated Aliphatics Listings

    Today's proposal does not affect the scope of the chlorinated 
aliphatics process wastes that already have been listed as hazardous in 
prior EPA rulemakings. These wastes include wastes designated as 
hazardous waste code F024 as well as a number of other chlorinated 
aliphatic wastes listed below in Table II-1. EPA is not soliciting 
comment on these existing hazardous waste listings and does not intend 
to respond to such comments, if received.
    Likewise, EPA is not soliciting comments in today's rule on the 
applicability of the existing chlorinated aliphatics listings to the 
provisions of CERCLA. Wastes listed as hazardous

[[Page 46479]]

under RCRA are by definition hazardous substances under CERCLA, and are 
included in the list of hazardous substances in 40 CFR 302.4, along 
with their corresponding reportable quantities (``RQs''). Hazardous 
substance RQs are those quantities of the designated chemical or waste 
that trigger certain reporting requirements if released to the 
environment. The previously listed hazardous wastes from chlorinated 
aliphatics production and their corresponding RQs are listed below in 
Table II-1.

 Table II-1.--List of Currently-Regulated Chlorinated Aliphatic Process
   Wastes and Corresponding Reportable Quantities as CERCLA Hazardous
                               Substances
------------------------------------------------------------------------
                   Hazardous substance                    RQ pounds (KG)
------------------------------------------------------------------------
F024--Process wastes, including but not limited to,            1 (0.454)
 distillation residues, heavy ends, tars, and reactor
 cleanout wastes from the production of certain
 chlorinated aliphatic hydrocarbons, by free radical
 catalyzed processes. These chlorinated aliphatic
 hydrocarbons are those having carbon chain lengths
 ranging from one to and including five, with varying
 amounts and positions of chlorine substitution. [This
 listing does not include wastewaters, wastewater
 treatment sludges, spent catalysts, and wastes listed
 in 40 CFR 261.31 or 261.32.]...........................
F025--Condensed light ends, spent filters and filter           1 (0.454)
 aids, and spent dessicant wastes from the production of
 certain chlorinated aliphatic hydrocarbons, by free
 radical catalyzed processes. These chlorinated
 aliphatic hydrocarbons are those having carbon chain
 lengths ranging from one to and including five, with
 varying amounts and positions of chlorine substitution.
K016--Heavy ends or distillation residues from the             1 (0.454)
 production of carbon tetrachloride.....................
K018--Heavy ends from the fractionation column in ethyl        1 (0.454)
 chloride production....................................
K019--Heavy ends from the distillation of ethylene             1 (0.454)
 dichloride in ethylene dichloride production...........
K020--Heavy ends from the distillation of vinyl chloride       1 (0.454)
 in vinyl chloride monomer production...................
K028--Spent catalyst from the hydrochlorinator reactor         1 (0.454)
 in the production of 1,1,1-trichloroethane.............
K029--Waste from the product steam stripper in the             1 (0.454)
 production of 1,1,1-trichloroethane....................
K030--Column bottoms or heavy ends from the combined           1 (0.454)
 production of trichloroethylene and perchloroethylene..
K095--Distillation bottoms from the production of 1,1,1-       1 (0.454)
 trichloroethane........................................
K096--Heavy ends from the heavy ends column from the           1 (0.454)
 production of 1,1,1-trichloroethane....................
------------------------------------------------------------------------

III. Today's Action

A. Summary of Today's Action

1. Scope of the Listing Determination
    Aliphatic hydrocarbons are compounds composed of the atoms of 
hydrogen and carbon, where the carbon atoms are linked by covalent 
bonds in an open-chain (straight and branched) structure, and those 
cyclic compounds that resemble the open-chain compounds. Aliphatics are 
distinguished from aromatic hydrocarbons, which are defined as benzene 
and compounds that resemble benzene in chemical behavior. For an 
aliphatic to be chlorinated, one or more hydrogen atoms have been 
chemically replaced with chlorine atoms. The chlorinated aliphatic 
chemicals, the wastes of which are described in the (existing) F024 
listing description, and identified in the consent decree, are those 
produced by free-radical catalyzed processes with carbon chain lengths 
ranging from one to five.
    EPA performed an initial review and investigation of the waste 
categories identified in the consent decree, as well as a review of 
chlorinated aliphatics production processes and the wastewaters and 
wastewater treatment sludges generated by these processes. The Agency 
decided, for the purpose of studying chlorinated aliphatic wastes, to 
divide the wastestreams into several distinct waste groupings. Waste 
groupings were defined to differentiate between unique residuals, as 
well as to differentiate between unique management practices (e.g., on-
site land treatment) and/or particular constituents (e.g., mercury). 
The Agency segregated chlorinated aliphatics wastewaters into two 
groupings, with one group being wastewaters generated from the 
production of vinyl chloride monomer using mercuric chloride catalyst 
in an acetylene-based process. These wastewaters were evaluated as one 
group due to the unique nature of this production process, the fact 
that these wastewaters are treated in a dedicated wastewater treatment 
system, and the presence of mercury in the wastestream. All other 
chlorinated aliphatic wastewaters were included in a second group and 
evaluated collectively. The Agency found that many producers of 
chlorinated aliphatics manufacture several different chlorinated 
aliphatic products at a single facility and commingle the wastewaters 
generated by all processes prior to treatment in a single wastewater 
treatment system.
    The Agency identified four waste groupings for wastewater treatment 
sludges generated by the chlorinated aliphatics industry. These waste 
groupings were defined based primarily upon the particular management 
practices used to manage the wastes, but also based on particular 
production processes. The Agency identified four waste groups for 
chlorinated aliphatics wastewater treatment sludges. These waste groups 
include sludges generated from the treatment of wastewaters from the 
production of:
     Ethylene dichloride and/or vinyl chloride monomer (EDC/
VCM);
     Vinyl chloride monomer using mercuric chloride catalyst in 
an acetylene-based process (VCM-A);
     Methyl chloride; and
     allyl chloride.
    The scope of today's notice does not include any other process 
residuals generated by the chlorinated aliphatics industry. In 
particular, the Agency is not re-evaluating previous listing 
determinations concerning wastes generated by chlorinated aliphatics 
production processes.
    The Agency also points out that the consent decree specifies that 
this listing determination ``shall include wastewaters and wastewater 
treatment sludges generated from the production of chlorinated 
aliphatics specified in the F024 listing'' (a listing which is limited 
to wastes from chlorinated aliphatic production using the ``free 
radical catalyzed process'' but does not include wastewaters or 
wastewater treatment sludges). However, for today's proposed rule the 
Agency did not restrict its evaluation of wastewaters and wastewater 
treatment sludges to only those generated from chlorinated aliphatics 
manufacturers using the free radical catalyzed process. In the 
rulemaking for the F024 listing (which includes process wastes such as 
distillation residues, heavy ends, and tars, but not wastewaters and

[[Page 46480]]

wastewater treatment sludges) we found that there were distinct 
differences in the amount and type of chemical constituents present in 
these production wastes as a direct result of the production process 
used. For example, the free radical catalyzed reactions tended to 
produce unwanted organic compounds, as well as the desired chemical 
product, because this type of reaction is less specific (in terms of 
desired product) than other types of processes used. As a result, the 
chemical constituents that were the basis for listing F024 includes 
many organic compounds that are more prevalent in process wastes 
(again, tars, heavy ends, etc.) generated from the free radical 
catalyzed process.
    However, in developing the information for today's proposed 
listing, EPA was concerned that limiting the scope of the investigation 
to free radical catalyzed processes might not be appropriate because of 
the different nature of wastewaters and wastewater treatment sludges as 
compared with the F024 process wastes. Wastewaters may be generated in 
different ways, including from scrubber waters, cooling waters, as well 
as reaction media, etc. Ultimately, our primary reason for not 
restricting our evaluation of wastewaters and wastewater treatment 
sludges to those generated by free radical catalyzed processes is that 
our preliminary analysis of these wastes indicated that the 
constituents of concern (i.e., dioxins, chloroform, arsenic) were not 
the same as the constituents of concern associated with the previously-
listed F024 and F025 wastes. In those previous listing determinations 
(which did not include wastewaters or wastewater treatment sludges) the 
Agency was able to distinguish risk levels of concern based upon 
particular production processes.
    In the case of today's proposed listing determination, we were not 
able to make such a distinction. The primary constituents of concern in 
the wastes we are proposing to list as hazardous in today's notice are 
dioxins, whereas dioxins were not a basis for listing the F024 and F025 
wastes. Data currently available to the Agency does not support a 
conclusion that wastewaters and wastewater treatment sludges generated 
by free radical catalyzed processes have significantly different 
concentrations of dioxins than other types of production processes used 
to manufacture chlorinated aliphatics. However, EPA requests comment 
and data addressing the issue of whether one type of manufacturing 
process (e.g., free radical catalyzation) versus all other potential 
processes (e.g., ionic catalyzed processes) would result in different 
levels of dioxins in the resulting wastestream. The Agency will 
consider modifying the listing description proposed in today's 
rulemaking as appropriate to account for distinctions identified in 
information available to EPA at the time of the final rule.
2. Summary of the Proposed Listing Determinations
    In today's notice, EPA is proposing to add three wastes generated 
by the chlorinated aliphatics industry to the list of hazardous wastes 
in 40 CFR 261.32. Below are the wastestreams EPA is proposing to list 
as hazardous with their corresponding proposed EPA Hazardous Waste 
Numbers.

K173  Wastewaters from the production of chlorinated aliphatic 
hydrocarbons, except for wastewaters generated from the production 
of vinyl chloride monomer using mercuric chloride catalyst in an 
acetylene-based process. This listing includes wastewaters from the 
production of chlorinated aliphatic hydrocarbons that have carbon 
chain lengths ranging from one to, and including five, with varying 
amounts and positions of chlorine substitution.
K174  Wastewater treatment sludges from the production of ethylene 
dichloride or vinyl chloride monomer (EDC/VCM).
K175  Wastewater treatment sludges from the production of vinyl 
chloride monomer using mercuric chloride catalyst in an acetylene-
based process.

    EPA is proposing to list these wastes because these residuals meet 
the criteria set out in 40 CFR 261.11(a)(3) for listing a waste as 
hazardous. EPA assessed and considered these criteria for all six 
wastestreams through the use of risk assessments and risk modeling, as 
well as a consideration of other pertinent factors. Today's proposed 
listing determination follows the elements of the Agency's listing 
decision policy that was presented in the proposed listing for wastes 
generated by the dye and pigment industries published in the Federal 
Register on December 22, 1994 (see 59 FR  66073). This policy uses a 
``weight-of-evidence'' approach in which calculated risk information is 
a key factor considered in making a listing determination.
    Upon promulgation of these proposed listings, wastes meeting the 
listing descriptions will become hazardous wastes and need to be 
managed in accordance with RCRA subtitle C requirements. Residuals from 
the treatment, storage, or disposal of the wastewater treatment sludges 
proposed to be listed as hazardous also will be classified as hazardous 
wastes pursuant to the ``derived-from'' rule (40 CFR 261.3(c)(2)(i)). 
1 Also, with certain limited exceptions, any mixture of a 
listed hazardous waste and a solid waste is itself a RCRA hazardous 
waste (40 CFR 261.3(a)(2)(iv), ``the mixture rule'').
---------------------------------------------------------------------------

    \1\ As explained later in this notice, residuals generated from 
the management of wastewaters proposed to be listed as hazardous 
(i.e., wastewater treatment sludges) will not be subject to the 
derived-from rule due to the fact that EPA conducted separate 
investigations of these residuals and they are the subject of 
independent listing determinations.
---------------------------------------------------------------------------

    In today's notice, the Agency is proposing an alternative approach 
to listing two of the wastes from chlorinated aliphatics processes as 
hazardous, rather than proposing to list these wastes in accordance 
with the Agency's traditional listing approach. The Agency is proposing 
a conditional listing approach for one waste, and as one of two 
alternative approaches for a second waste, because the Agency has 
evaluated the ways in which the wastes are likely to be managed and has 
determined that certain waste management activities would present 
significant risks but that others would be protective of human health 
and the environment. Under a contingent management approach, EPA is 
proposing to list particular wastes as hazardous only if the wastes are 
managed in a way other than the manner in which the Agency has 
determined is protective of human health and the environment. In 
implementing a conditional-listing approach, the Agency is proposing 
that wastes that fall outside the scope of the listing description 
(e.g., are destined for the appropriate type of disposal) are non-
hazardous when generated. However, if it turns out that the waste 
actually is not handled in accordance with the conditions of the 
listing at any point in its management, the generators or other 
handlers of the waste would be subject to various enforcement actions 
or, depending on the violations, the waste could become a hazardous 
waste and may even be considered hazardous from the point of 
generation. The Agency's proposed conditional-listing approach for 
wastes generated from chlorinated aliphatics processes is further 
discussed in section III.E of today's notice.
    Today's action also proposes not to list as hazardous the following 
three wastes:
     Process wastewaters from the production of vinyl chloride 
monomer using mercuric chloride catalyst in an acetylene-based process,
     Wastewater treatment sludges from the production of methyl 
chloride, and

[[Page 46481]]

     Wastewater treatment sludges from the production of allyl 
chloride.
3. Summary of the Remainder of this Preamble
    Section III.B. describes the chlorinated aliphatics industry. 
Section III.C. describes how the information was gathered in support of 
today's proposed rule. Section III.D. is a description of the risk 
assessment performed for three of the wastes evaluated in today's rule, 
including chlorinated aliphatic wastewaters, EDC/VCM sludges, and 
methyl chloride sludges, and the results of these assessments. Section 
III.E provides the rationale for the proposed listing decisions for all 
six wastes analyzed in today's rule. Because full risk analyses were 
not necessary for VCM-A wastewaters, VCM-A wastewater treatment 
sludges, or allyl chloride sludges, we discuss our assessment of risks 
attributable to each of these wastes in the same sections where we 
describe our listing decisions for the wastes. Section IV contains the 
economic assessment of the industry and the estimated impact of today's 
proposed listing determinations. Section V describes the proposed land 
disposal restriction requirements for those wastes we propose to list 
as hazardous, along with determinations of whether there is adequate 
treatment and disposal capacity for these wastes. Sections VI 
(compliance dates), VII (state authority), VIII (designating CERCLA 
hazardous substances) and IX (administrative assessments) discuss other 
analyses required by statute and various executive orders.

B. Description of the Industry

    In 1992, when EPA began gathering information about the U.S. 
chlorinated aliphatics industry, it consisted of 27 facilities owned by 
20 corporations. However, as a result of information updates in 1997, 
we determined that two chlorinated aliphatics facilities had closed and 
two additional facilities manufacture de minimis quantities of 
chlorinated aliphatics, lowering the number of facilities affected by 
today's proposed rulemaking to 23 and corporations to 19.
    Chlorinated aliphatics production facilities are located primarily 
in and around the petroleum/petrochemical industry which generally is 
located along the Gulf Coast. The majority of facility locations are 
fully integrated petrochemical processing facilities. A few facilities 
are co-located with other chemical manufacturing and/or petroleum 
refining facilities. These integrated facilities often manage wastes 
generated across different production processes within the same waste 
management systems. For example, these facilities often combine 
chlorinated aliphatic wastewaters with non-chlorinated aliphatics 
wastewaters prior to treatment. The combined wastewater treatment 
system generates a commingled sludge. In addition, there are facilities 
that manage chlorinated aliphatics wastewaters in separate or dedicated 
wastewater treatment systems. For the purpose of this listing 
determination, the Agency refers to these treatment systems, and 
resulting sludges, as ``dedicated'' systems and ``dedicated'' sludges.
    Nearly 10 million metric tons of chlorinated aliphatics were 
produced in 1996. More than 85 percent of the chlorinated aliphatic 
products manufactured in 1996 was ethylene dichloride and vinyl 
chloride monomer (EDC/VCM) manufactured via the ``balanced process.'' 
This process involves the production of EDC as an intermediate product 
using direct chlorination and oxyhydrochlorination of ethylene, 
followed by cracking to produce VCM. Other chlorinated aliphatics 
production includes chlorinated methanes, methyl chloride, and a 
variety of other products.

C. Overview of EPA's Information Collection Activities

    EPA's investigation of the wastes generated by the chlorinated 
aliphatics industry can be characterized in terms of two major 
information collection efforts: field investigations and survey 
evaluation. The Agency's field investigations included engineering site 
visits, ``familiarization sampling'' (sample collection and analysis to 
gain a preliminary understanding of the nature and concentration of 
potential constituents of concern), and ``record sampling'' (sample 
collection and analysis to provide data to use in assessing the 
potential risks posed by the wastes). The survey effort included the 
development, distribution, and assessment of an extensive industry-wide 
RCRA Section 3007 survey. Each of these efforts is summarized below.
1. Field Investigations and Sampling
    EPA initiated its work activities with a series of engineering site 
visits. The primary purpose of the site visits was to gather 
information on chlorinated aliphatic manufacturing processes and the 
generation, management, and characterization of the consent decree 
wastes. In addition, the field teams identified potential record 
sampling locations. The Agency conducted site visits at 16 facilities 
prior to record sampling; site visit facilities were selected based on 
a goal of obtaining first hand information from a representative 
sampling of all chlorinated aliphatic manufacturers as well as all 
relevant manufacturing and waste management processes, including an 
investigation of dedicated wastewater treatment units.
    Concurrently, the Agency initiated the analytical phase of this 
listing determination with the development of a Quality Assurance 
Project Plan (QAPjP) for sampling and analysis, followed by collection 
of 15 familiarization samples from three different manufacturing 
facilities (collected during the engineering site visits). The purpose 
of collecting familiarization samples is to assess the effectiveness of 
the analytical methods identified in the QAPjP for the analysis of the 
residuals of concern.
    Upon successful completion of the familiarization sampling and 
analysis effort, the Agency initiated record sampling and analysis of 
the consent decree wastes. The Agency sampled wastewaters and 
wastewater treatment sludges from twelve facilities. During a four-
month period beginning in April of 1997, the Agency collected 52 
samples, excluding additional blanks and matrix spike/matrix spike 
duplicates(MS/MSD) collected for quality assurance purposes. Of these 
52 samples, 41 were wastewater samples, and 11 were wastewater 
treatment sludge samples.
2. RCRA Section 3007 Survey
    EPA developed an extensive questionnaire under the authority of 
Section 3007 of RCRA for distribution to the chlorinated aliphatics 
manufacturing industry. The purpose of the survey was to gather 
information about solid and hazardous waste generation and management 
practices in the U.S. chlorinated aliphatics manufacturing industry 
necessary to support the listing determination. The questionnaire 
covered topics such as chlorinated aliphatic product information, 
facility and unit process flow diagrams, process descriptions, residual 
generation and residual management profiles.
    The Agency distributed the survey in November of 1992 to 57 
facilities and/or corporations identified as potential chlorinated 
aliphatics manufacturers from the most recent information available at 
the time. Of the 57 surveys distributed, completed surveys were 
received from 27 facilities. These facilities represent 20 companies 
that reported that they had manufactured chlorinated aliphatics in 
1991. The remaining facilities notified EPA that they had either 
stopped operations or

[[Page 46482]]

did not manufacture chlorinated aliphatic products.
    We also conducted an exhaustive engineering review of the submitted 
surveys for accuracy and completeness. Data from the survey responses 
was then entered into a data base known as the Chlorinated Aliphatics 
Industry Studies Data Base (ISDB). We conducted quality assurance 
reviews of the ISDB to identify any inappropriate entries and missing 
data links. The exhaustive engineering review of each facility's 
response resulted in follow-up letters and/or telephone calls to 
facility representatives seeking clarifications, corrections, and 
additional data where needed. The responses to these requests for 
clarification, along with additional information gathered during 
engineering site visits and familiarization and record sampling 
activities were entered into the data base.
    In 1996 we conducted a review of data collected previously, and re-
contacted facility representatives to verify the status of chlorinated 
aliphatics manufacturing operations. In June of 1997, the Agency sent 
requests for updated data (for calendar year 1996) regarding consent 
decree wastes generated to each facility. We processed the data 
received from this request in the same manner as the original RCRA 
surveys, and entered the new information into the ISDB. Between 1993 
and 1996, two chlorinated aliphatics manufacturers ceased operations, 
resulting in a universe of 23 chlorinated aliphatics manufacturing 
facilities owned and operated by 19 different companies. Each of the 23 
current manufacturers of chlorinated aliphatics generate at least one 
wastestream identified in the consent decree. All 23 facilities 
generate at least one wastewater residual, while 14 facilities reported 
that they generate wastewater treatment sludges.

D. What Are the Risks Associated With Management of Wastewaters and 
Wastewater Treatment Sludges From the Production of Chlorinated 
Aliphatic Chemicals?

    As discussed in Section III.A.2. of this preamble, EPA considers 
the Listing criteria set out in 40 CFR 261.11, as well as any other 
information relevant to the criteria, in making listing determinations. 
The criteria provided in 40 CFR 261.11 include eleven factors for 
determining ``substantial present or potential hazard to human health 
and the environment.'' Nine of these factors, as described generally 
below, are directly incorporated into EPA's completion of a risk 
assessment for the wastestreams of concern:
     Toxicity (Sec. 261.11(a)(3)(i)) is considered in 
developing the health benchmarks used in the risk assessment modeling.
     Constituent concentrations and waste quantities 
(Sec. Sec. 261.11(a)(3)(ii) and 261.11(a)(3)(viii)) are used to define 
the initial conditions for the risk evaluation.
     Potential to migrate, persistence, degradation, and 
bioaccumulation of the hazardous constituents and any degradation 
products (261.11(a)(3)(iii), 261.11(a)(3)(iv), 261.11(a)(3)(v), and 
261.11(a)(3)(vi)) are all considered in the design of the fate and 
transport models used to determine the concentrations of the 
contaminants to which individuals are exposed.
    We consider two of the remaining factors, plausible mismanagement 
and other regulatory actions (Sec. Sec. 261.11(a)(3)(vii) and 
261.11(a)(3)(x)) in establishing the waste management scenario(s) 
modeled in the risk assessment.
    EPA conducted analyses of the risks posed by wastewaters and 
wastewater treatment sludges from the production of chlorinated 
aliphatic chemicals to assist in the determination of whether the 
wastes meet the criteria for listing set forth in 40 CFR 261.11(a)(3). 
This section (III.D.) discusses the human health risk analyses and 
ecological risk screening analyses EPA conducted to support our 
proposed listing determinations for chlorinated aliphatics wastewaters 
(other than VCM-A wastewaters), EDC/VCM wastewater treatment sludges, 
and methyl chloride wastewater treatment sludges. We consider the risk 
analyses in developing our listing decisions for each of the 
wastestreams (described in Sections III.E.1.a. for chlorinated 
aliphatics wastewaters, III.E.2. for EDC/VCM sludges, and III.E.4. for 
methyl chloride sludges). The risk analyses we describe in this section 
(III.D.) are presented in detail in the Risk Assessment Technical 
Background Document for the Chlorinated Aliphatics Listing 
Determination which is located in the docket for today's proposed rule.
    Because full risk analyses were not necessary for VCM-A 
wastewaters, VCM-A sludges, or allyl chloride sludges, we discuss our 
assessment of risks attributable to each of these wastes in the same 
sections where we describe our listing decisions for each of the 
wastes, that is, Sections III.E.1.b., III.E.3, III.E.5, respectively.
1. What are the Risks for Potential Human Receptors?
a. What was EPA's Approach to Conducting the Human Health Risk 
Assessment?
    EPA's human health risk analyses for chlorinated aliphatics 
wastewaters and EDC/VCM and methyl chloride sludges provide estimates 
of the incremental human health risks resulting from exposure to 
contaminants detected in these wastes. The incremental human health 
risks are expressed as estimates of excess lifetime cancer risk for 
individuals (``receptors'') who may be exposed to carcinogenic (cancer-
causing) contaminants and hazard quotients (HQs) for those contaminants 
that produce noncancer health effects. Excess lifetime cancer risk is 
the incremental probability (chance) of an individual developing cancer 
over a lifetime as a result of exposure to a carcinogen. A hazard 
quotient is the ratio of an individual's chronic daily dose of a 
noncarcinogen to an acceptable daily dose for chronic exposures to the 
noncarcinogen.
    EPA used two different methods of analysis to estimate risks. These 
methods are called ``deterministic risk analysis'' and ``probabilistic 
risk analysis.'' A deterministic risk analysis produces a point 
estimate of risk or hazard for each receptor based on using a single 
value for each parameter in the analysis. A probabilistic analysis 
calculates risk or hazard by allowing some of the parameters to have 
more than one value, consequently producing a distribution of risk or 
hazard for each receptor. A parameter is any one of a number of inputs 
or variables (such as waste volume or distance between the waste 
management unit and the receptor) required for the fate and transport 
and exposure models and equations that EPA uses to assess risk. (In 
some cases EPA treats multiple parameters as a single parameter for the 
purpose of conducting our analyses. We do this to prevent inadvertently 
combining parameters in our analyses in ways that are unrealistic. For 
example, EPA treats environmental setting [location] parameters such as 
climate, depth to groundwater, aquifer type as a single set of 
parameters. We believe that, for example, allowing the climate from one 
location to be paired with the depth to groundwater for another 
location could result in a scenario that would not occur in nature.)
    EPA conducts both ``central tendency'' and ``high end'' 
deterministic risk assessments to attempt to quantify the cancer risk 
or non-cancer hazard for the ``average'' receptor in the population

[[Page 46483]]

(the central tendency risk) and the risk or hazard for individuals in 
small, but definable ``high end'' segments of the population (the high 
end risk). For central tendency deterministic risk analyses, we set all 
parameters at their central tendency values. For the chlorinated 
aliphatics risk assessments, the central tendency values generally are 
either mean (average) or 50th percentile (median) values.
    We use high end deterministic risk analysis to predict the risks 
and hazards for those individuals exposed at the upper range of the 
distribution of exposures. EPA's Guidance For Risk Characterization 
(EPA 1995) 2 advises that ``conceptually, high end exposure 
means exposure above about the 90th percentile of the population 
distribution, but not higher than the individual in the population who 
has the highest exposure,'' and recommends that ``* * * the assessor 
should approach estimating high end by identifying the most sensitive 
variables and using high end values for a subset of these variables, 
leaving others at their central values.'' For the chlorinated 
aliphatics high end deterministic risk analyses, EPA set two parameters 
at their high end values (generally 90th percentile values), and set 
all other parameters at their central tendency values. We used a 
``sensitivity analysis'' to identify the two parameters that we set at 
high end. A sensitivity analysis is an iterative procedure in which an 
analysis is performed by alternately setting different parameters at 
high end to identify the parameters that most influence the analysis' 
outcome. EPA compares the different results generated by the 
sensitivity analysis and selects the two high end parameters to which 
the analysis was ``most sensitive,'' that is, the two parameters that 
are expected to generate the greatest estimate of risk or hazard.
---------------------------------------------------------------------------

    \2\ EPA. 1995. Guidance for Risk Characterization. U.S. 
Environmental Protection Agency Science Policy Council. February.
---------------------------------------------------------------------------

    EPA used probabilistic risk assessment to support the results of 
the deterministic risk analyses and to allow EPA to quantify individual 
risk at selected percentiles of the risk distribution (for example, 
50th percentile, 90th percentile, 95th percentile). EPA conducted 
probabilistic risk analyses for those combinations of receptor, 
contaminant, and pathway for which risk or hazard estimated using a 
deterministic analysis exceeded the following criteria: a cancer risk 
of 1 x 10 -6 or a hazard quotient of 1. In a probabilistic 
analysis, each parameter may have more than one value. EPA develops 
``probability density functions'' (PDFs), distributions that describe 
the full range of values that the various input parameters may have. 
Some of the parameters in the probabilistic analysis are set as 
constant values because (1) there are insufficient data to develop a 
PDF; (2) EPA made assumptions to simplify the analysis in cases where 
such simplifications would improve the efficiency of the analysis 
without significantly affecting the results; (3) site-specific 
constants are available; or (4) the analysis has not been shown to be 
sensitive to the value of the parameter, that is, even if the parameter 
varies, the resulting risk estimate does not vary significantly. The 
Risk Assessment Technical Background Document for the Chlorinated 
Aliphatics Listing Determination describes the input parameters used in 
the probabilistic analysis. In the probabilistic analysis, risk is 
approximated through repetitive calculation of the fate and transport 
and exposure equations and models using input parameters randomly 
selected from the PDFs. The result of the probabilistic analysis is a 
distribution of the risks or hazards for each of the receptors.
    The human health risk assessments that EPA conducted to support the 
chlorinated aliphatics listing determination included four primary 
tasks: (1) establishing that there are constituents in the wastes that 
are of concern to the Agency and that warrant analysis to determine 
their risk to human health; (2) establishing a scenario under which 
contaminants are released from a waste management unit and subsequently 
are transported in the environment to a human receptor; (3) estimating 
the concentrations of contaminants to which the receptor might be 
exposed; (4) quantifying the receptor's exposure to contaminants and 
the contaminants' toxicity to the receptor; and (5) describing the 
receptor's predicted risk. The following sections discuss how EPA 
completed each of these tasks for the risk assessments conducted to 
support the chlorinated aliphatics listing determination.
b. How Did EPA Determine Which Waste Constituents and Waste Volumes 
Would Be Evaluated in the Risk Assessments?
    To support the chlorinated aliphatics listing determination, EPA 
collected and analyzed samples of wastewaters from the production of 
chlorinated aliphatic chemicals, wastewater treatment sludges from the 
production of EDC/VCM, and wastewater treatment sludges from the 
production of methyl chloride (see Section III.E of today's preamble, 
as well as the Background Document for Identification and Listing of 
Chlorinated Aliphatics Production Wastes, for further discussion of 
EPA's waste characterization efforts). We used the results of these 
waste analyses to establish the ``constituents of potential concern'' 
(COPCs) in the wastes. We derived waste volume information from data 
provided by facilities in their RCRA Section 3007 questionnaire 
responses.
    EPA collected and analyzed 41 samples of wastewaters generated from 
the production of chlorinated aliphatic chemicals. EPA collected six of 
these samples at the influent (or ``headworks'') of wastewater 
treatment systems that manage only wastewaters derived from the 
production of chlorinated aliphatic chemicals. We call these samples 
``dedicated'' chlorinated aliphatics wastewater samples,3 
and we chose to use these samples in our assessment of the risks and 
hazards attributable to the management of chlorinated aliphatic 
wastewaters. (The assessment of dedicated sample data allows us to 
evaluate without question what risks are attributable to the wastes of 
concern to the Agency.) Because we used analytical data for dedicated 
chlorinated aliphatics wastewater samples in our analysis, we also used 
dedicated chlorinated aliphatic wastewater volumes in our analysis. We 
identified eight wastewater volumes that represent the volumes of 
dedicated chlorinated aliphatics wastewaters discharged to the 
headworks of chlorinated aliphatics facility wastewater treatment 
systems.
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    \3\ ``Dedicated'' chlorinated aliphatic wastewaters are those 
that are comprised only of chlorinated aliphatics process 
wastewaters, that is, wastewaters generated from the production of 
the chlorinated aliphatic chemicals of concern to this listing 
determination.
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    EPA collected and analyzed seven samples of nonhazardous EDC/VCM 
sludge. (Some sludges generated by this industry already are designated 
as hazardous because they include material derived from wastes that EPA 
previously listed as hazardous waste.) Four were samples of sludges 
that were derived from wastewater treatment systems that manage only 
EDC/VCM process wastewaters. These samples are ``dedicated'' EDC/VCM 
sludge samples. Three were samples of sludges that result from the 
treatment of EDC/VCM process wastewaters combined with wastewaters from 
non-EDC/VCM processes and sources. EPA chose to use only the dedicated 
EDC/VCM sample data in our analysis. Because we used

[[Page 46484]]

analytical data for dedicated EDC/VCM sludge samples in our analysis, 
we also used ``dedicated'' EDC/VCM sludge volumes. EPA divided the 
volume of wastewater attributable to EDC/VCM processes by the total 
volume of wastewater influent, and applied the resultant ratio to the 
total sludge volumes to obtain the volume of wastewater treatment 
sludge attributable to EDC/VCM processes (that is, the ``dedicated `` 
EDC/VCM sludge volume).
    The methyl chloride sludge, generated by only one facility, results 
from treatment of the combined wastewaters from the facility's methyl 
chloride production process and other facility processes and sources. 
The facility reports that approximately 18 percent of the wastewater 
that generates the sludge is from the methyl chloride process. The 
remainder of the wastewater is from other processes. Because the 
sludge, as generated, is not dedicated, and there is no means to obtain 
a dedicated sample of the methyl chloride sludge, we conducted our risk 
assessment using the sample data for the nondedicated methyl chloride 
sludge sample, and, comparably, the nondedicated (total) methyl 
chloride sludge volume.
    Using the results of the analysis of the waste samples, EPA 
developed a list of ``chemicals of potential concern'' (COPCs) for the 
chlorinated aliphatics wastewaters, EDC/VCM sludges, and methyl 
chloride sludges. The COPCs are the constituents which were the subject 
of EPA's risk assessment. EPA developed the COPC lists by taking the 
complete list of detected constituents in the wastes and eliminating 
constituents from the list that occurred at concentrations clearly 
below levels of concern, based on screening analyses developed to 
maximize risk estimates. For chlorinated aliphatics wastewaters and 
EDC/VCM sludges, EPA also eliminated constituents when a constituent 
was detected in only one of the samples and the concentration of the 
constituent in the one sample was qualified with the ``J'' qualifier, 
indicating that the constituent was detected below the quantitation 
limit and the reported value was estimated. Specifically, the 
laboratory detected 69 constituents in chlorinated aliphatics 
wastewater samples of which we eliminated 28; 53 constituents in EDC/
VCM sludges of which we eliminated 16; and 19 constituents in methyl 
chloride sludges of which we eliminated 11.
    Six polychlorinated dibenzodioxin (``dioxin'') congeners and ten 
polychlorinated dibenzofuran (``furan'') congeners were among the 
constituents detected in samples of the chlorinated aliphatics 
wastewaters, EDC/VCM sludges, and methyl chloride sludges and evaluated 
in the risk assessment. EPA classifies the furan congeners and certain 
polychlorinated biphenyl (PCB) congeners as ``dioxin-like compounds'' 
because of their structural similarity to the dioxins (EPA 1994a 
4). In today's preamble we use the term ``dioxins'' to 
represent both the dioxin and furan congeners. Our use of the term 
``dioxins'' does not refer to dioxin-like PCBs because we did not 
analyze for PCBs in our waste samples from the chlorinated aliphatics 
industry since we do not expect PCBs to be constituents of the 
chlorinated aliphatics wastes that are the subject of today's listing 
determination.
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    \4\ EPA. 1994a. Estimating Exposure to Dioxin-Like Compounds, 
Volume I: Executive Summary. Review Draft. EPA/600/6-88/005Ca. 
Office of Research and Development. June.
---------------------------------------------------------------------------

c. What Exposure Scenarios Did EPA Evaluate?
    Prior to conducting the risk assessments, EPA had to establish that 
there is a plausible scenario under which a receptor might be exposed 
to contaminants in the wastewaters and sludges. Establishing this 
scenario required that EPA determine:
     How the waste is managed or is likely to be managed;
     How contaminants could be released from the waste 
management unit;
     How contaminants could be transported in the environment 
to a point of contact with a receptor; and
     How a receptor could be exposed to the contaminants.
    One respondent to EPA's Sec. 3007 questionnaire reported that they 
discharge a portion of their nonhazardous chlorinated aliphatics 
wastewaters to nonhazardous underground injection wells. Section 
III.E.1.a.i. discusses EPA's evaluation of the underground injection 
waste management scenario. Twenty-three respondents reported that they 
manage their nonhazardous or exempt chlorinated aliphatics wastewaters 
in tanks. Because management of wastewaters in tanks is the dominant 
wastewater management practice in the chlorinated aliphatics industry, 
EPA chose to evaluate tanks in our risk assessment for chlorinated 
aliphatics wastewaters. For reasons discussed in III.E.1.a.i., EPA 
chose to evaluate risks attributable to management of chlorinated 
aliphatics wastewaters in uncovered aerated biological treatment tanks.
    One respondent to EPA's Sec. 3007 questionnaire reported that they 
manage their EDC/VCM wastewater treatment sludges in an onsite land 
treatment unit. All other respondents reported that nonhazardous EDC/
VCM sludges are managed in landfills. Eight facilities send EDC/VCM 
sludges to offsite nonhazardous waste landfills, two facilities manage 
EDC/VCM sludge in onsite nonhazardous industrial waste landfills, and 
one facility manages their nonhazardous EDC/VCM sludge in an onsite 
hazardous waste landfill (see section III.E.2.a. in today's preamble 
for a description of current methods for managing EDC/VCM sludges). For 
this assessment, EPA evaluated the risks associated with management of 
EDC/VCM sludges in unlined municipal landfills and in a land treatment 
unit. Because the only facility that generates methyl chloride sludges 
manages them in an onsite nonhazardous industrial waste landfill, EPA 
evaluated this management scenario in our risk assessment for methyl 
chloride sludges. The Risk Assessment Technical Background Document for 
the Chlorinated Aliphatics Listing Determination provides a complete 
discussion of the parameters that define the characteristics of the 
waste management units.
    EPA determined that releases from all of the waste management units 
(tank, land treatment unit, and landfill) could occur through release 
of vapor emissions to the air. In addition, for the land treatment unit 
and the landfill, EPA determined that releases could occur through 
leaching of the waste into the subsurface. We assumed that the 
chlorinated aliphatics industry's tanks retain sufficient structural 
integrity to prevent wastewater releases to the subsurface (and 
therefore to groundwater), and that overflow and spill controls prevent 
wastewater releases to the ground surface. For the land treatment unit, 
releases also could occur through release of particulate emissions to 
the air and runoff and erosion of waste from the unit. EPA assumed that 
wastewater would entrain any particulate matter such that particulates 
would not be released from the tanks. EPA did not evaluate particulate 
emissions from the landfills because the moisture content of the 
sludges (41 to 74 percent moisture) would prevent generation and 
release of particulates to the air in the time between placement of the 
waste in the landfill and application of daily cover or a new day's 
waste addition. EPA also assumed that runon/runoff controls would 
prevent releases from the landfills due to erosion and runoff.
    EPA also evaluated the mechanisms and pathways by which 
contaminants

[[Page 46485]]

might be transported to the points where receptors are exposed. The 
mechanisms and pathways we evaluated are as follows:
     Eroded waste can be transported by runoff and deposited 
onto the soil and into surface water bodies.
     Leachate can migrate through the unsaturated 5 
zone to the saturated 6 zone, where contaminants are 
transported in groundwater to drinking water wells and to points of 
discharge to surface water bodies.
---------------------------------------------------------------------------

    \5\ The unsaturated (vadose) zone is a subsurface zone in which 
the pore spaces contain both water and air.
    \6\ The saturated zone is a subsurface zone in which all pore 
spaces are full of water.
---------------------------------------------------------------------------

     Vapor emissions can remain dispersed in the air, or can be 
deposited through wet and dry deposition. Specifically, EPA models:
     The concentration of vapor phase contaminants in air,
     The diffusion of vapor phase contaminants into plants,
     The diffusion of vapor phase contaminants into surface 
water,
     Wet deposition of vapors onto soils and surface water (for 
example, due to wash-out [scavenging] by precipitation).
     Dry deposition of vapors onto soils (for example, due to 
density).
     Although we do not evaluate wet and dry deposition of 
vapors onto plants, we do assume that wet and dry deposition of vapors 
onto soils increase the contaminant concentrations in the soil and 
result in additional uptake of contaminants into plants via soil-to-
plant uptake.
     Particulate emissions can remain dispersed in the air or 
be deposited through wet deposition (in precipitation) or dry 
deposition (particle settling). We assume that particulates may be 
deposited onto soil and surface water through both wet and dry 
deposition, and onto plants through dry deposition.
    Human receptors indirectly may come into contact with vapors that 
diffuse into vegetation, particulates that are deposited on vegetation, 
or contaminants that are taken up by vegetation from the soil through 
exposure to contaminated home-grown fruits and vegetables, as well as 
exposure to contaminated beef and dairy products derived from cattle 
which have ingested contaminated forage, silage, grain, and surface 
soil. Receptors that ingest fish also indirectly may come into contact 
with contaminants in air-borne vapors and particulates (through vapor 
diffusion into surface water, vapor deposition onto surface water, and 
particulate deposition onto surface water), contaminated groundwater 
(through groundwater discharge into surface water), and runoff and 
eroded soil that enter surface water.
    EPA determined that the following receptors reasonably represent 
the types of individuals that could be exposed to contaminants in 
chlorinated aliphatics wastes, and were the receptors evaluated in our 
risk analyses:

 an adult resident
 the child of a resident
 a home gardener
 a farmer
 the child of a farmer
 a fisher

The following sections describe briefly EPA's primary assumptions 
regarding the characteristics and activities of each of the receptor 
types, and the routes by which each receptor is exposed.
    Adult Resident and Child of Resident--We assume that an adult and 
child reside near the waste management unit. The residential receptors 
inhale vapors and particulate matter that are dispersed in the ambient 
air. EPA assumes that household water is supplied to the residential 
receptors by a domestic groundwater well that is located near their 
home. The adult resident and child of the resident drink water that 
comes from the well. We assume that the adult resident inhales vapors 
that are emitted from the water that they use in their house (for 
example, during showering), and that the adult resident's skin also is 
exposed to groundwater when he/she bathes. The residential receptors do 
not ingest foods that are grown in the vicinity of their home, however 
they do incidentally ingest surface soil from their yard.
    Home Gardener--We assume that the residential receptor may have a 
home garden. The home gardener grows fruit, exposed vegetables 
(vegetables with edible parts that are exposed at land surface), and 
root vegetables. Approximately 23 percent of the exposed vegetables, 11 
percent of the root vegetables, and 12 percent of the fruits eaten by 
the gardener are grown in his/her garden (EPA 1997a, Table 13-71) 
7. The gardener's other characteristics and activities are 
the same as those of the adult resident.
---------------------------------------------------------------------------

    \7\ EPA. 1997a. Exposure Factors Handbook, Volumes I, II, and 
III. Office of Research and Development, Washington, D.C., EPA/600/
P-95/002Fa, b, c. August 1997; www.epa.gov/ordntrnt/ord/webpubs/
exposure/index.html.
---------------------------------------------------------------------------

    Fisher--We assume that the residential receptor may be a 
recreational angler. Approximately 32 percent of the fish eaten by the 
fisher are from a stream located near the waste management unit (EPA 
1997a, Table 13-71). The fisher's other characteristics and activities 
are the same as those of the adult resident.
    Adult Farmer and Child of Farmer--We assume that a farmer raises 
fruits, exposed vegetables, root vegetables, beef cattle, and dairy 
cattle in an agricultural field located near the waste management unit. 
Approximately 42 percent of the exposed vegetables, 17 percent of the 
root vegetables, 33 percent of the fruits, 49 percent of the beef, and 
25 percent of the dairy products eaten by the farmer and the child of 
the farmer are grown/raised on the farmer's agricultural field (EPA 
1997a, Table 13-71). We assume that the farmer incidentally ingests 
soil from the agricultural field, and that the child of the farmer 
incidentally ingests soil from his/her yard. The farmer's and child's 
exposure to groundwater via ingestion, inhalation, and dermal contact 
are the same as that for the adult resident and child of the resident.
    EPA establishes the locations of receptors relative to waste 
management units based on information obtained from national surveys. 
Exposure to groundwater occurs through the use of water from drinking 
water wells, and exposure via nongroundwater pathways occurs through 
runoff/erosion and releases to air. Therefore, ``distance to receptor'' 
for groundwater exposure pathways actually is the distance to the 
drinking water well that the receptor is using (the ``receptor well''). 
``Distance to receptor'' for nongroundwater pathways is the distance to 
the residence where the receptor is inhaling air or contacting soil, 
the distance to the garden where the receptor is growing fruits and 
vegetables, or the distance to the field where the receptor is growing 
crops or raising livestock. Consequently, EPA uses different databases 
to establish ``distance to receptor,'' depending on whether we are 
evaluating a groundwater or a nongroundwater pathway.
    For analysis of the nongroundwater pathway (air pathways and 
erosion/runoff) risks in the deterministic analysis we assume that the 
receptors live either 75 meters (m) (high end) or 300 m (central 
tendency) from the waste management unit. The distance of 250 feet (ft) 
(approximately 75 m) is based on the actual measured distance to the 
nearest resident for the worst-case facility evaluated in the risk 
assessment conducted to support the ``Hazardous Waste Treatment, 
Storage, and Disposal Facilities--Organic Air Emissions Standards for 
Process Vents and Equipment Leaks Final Rule'' (55 FR

[[Page 46486]]

25454), and was used as distance to the nearest resident for that 
rulemaking. In the same risk assessment, EPA identified the receptor 
distance of 1000 ft (approximately 300 m) as the median distance in a 
random sample of distances to the nearest residence. For the 
probabilistic analysis, we assume the receptors live either 50, 75, 
100, 200, 300, 500, or 1000 m from the waste management unit. For air 
pathway analyses, we always assume that the receptors (including 
cattle) are located along the centerline of the area most greatly 
impacted by air releases from the waste management units. However, at 
distances of a few hundred meters from the waste management unit, the 
air concentrations within about a 100 meter lateral distance do not 
vary appreciably.
    For deterministic analyses we assume that a receptor well is 
located 102 m (high end) or 430 m (central tendency) from the waste 
management unit, and that the receptor well is located on centerline of 
the contaminant plume (high end) or halfway between the centerline and 
the edge of the contaminant plume (central tendency). The 102 m 
distances is the 10th percentile value in the distribution of distances 
derived from EPA's 1988 survey of Solid Waste (Municipal) Landfill 
Facilities (DPRA 1993 8). The 430 m value is the 50th 
percentile value in that same distribution. For the Monte Carlo 
analysis, the distance from the waste management unit to the receptor 
well is based on the complete distribution of distances to receptor 
well reported by the survey respondents, and ranges from 0.02 m (the 
location of the closest reported well was 0 m) to 1604 m (the maximum 
distance for which EPA requested receptor well information was 1 mile). 
For the Monte Carlo analysis we assume that the receptor well is 
located anywhere within the contaminant plume.
---------------------------------------------------------------------------

    \8\ DPRA. 1993. Parameter Values for Developing Nationwide 
Regulations with the EPA's Composite Model for Landfills (EPACML). 
EPA Contract Number 68-WO-0029. July.
---------------------------------------------------------------------------

    The Risk Assessment Technical Background Document for the 
Chlorinated Aliphatics Listing Determination provides a complete 
discussion of the values of additional parameters that define the 
characteristics of each receptor, such as the amounts of contaminated 
food and water they ingest, their inhalation rates, and how long they 
live near the waste management unit.
d. How Did EPA Predict What Contaminant Concentrations Are at the 
Points Where Receptors Are Exposed?
    EPA conducts contaminant fate and transport modeling and indirect 
exposure modeling to determine what the concentrations of contaminants 
will be in the media (for example, groundwater, air, soil, food items) 
that the receptor comes into contact with. These concentrations are 
called ``exposure point concentrations'' (that is, they are the 
contaminant concentrations at the point where the receptor is exposed 
to the contaminants). There are a number of computer-based models and 
sets of equations that EPA uses to predict exposure point 
concentrations. In the following sections we briefly discuss these 
models and equations and their application in the risk analyses.
i. Partitioning Model
    For the landfill and the land treatment unit, EPA uses a series of 
``partitioning'' equations to determine how much contaminant mass is 
retained in the waste management unit and how much is released into the 
environment. These equations are based upon equations presented in a 
series of articles by Jury et al. (Jury et al. 1983, 1984, and 1990 
9). EPA used the partitioning equations to estimate the mass 
of a contaminant that will be lost from the land treatment unit due to 
volatilization into the air, contaminant leaching into the subsurface, 
runoff from the land treatment unit, and degradation. For the landfill 
scenarios, EPA used the partitioning equations to determine how much of 
the contaminant mass would be lost due to volatilization into the air; 
EPA assumed that the remainder of the mass would be available to leach 
into the subsurface. We assumed that volatilization losses could occur 
prior to the landfill being covered with daily cover or daily waste 
addition, through the daily cover or daily waste addition, and through 
the cap that is placed on the landfill after closure. For the landfill, 
we used toxicity characteristic leaching procedure (TCLP) analytical 
results (rather than the partitioning equations) as the predictor of 
leachate concentration. The TCLP is an analytical procedure that 
``leaches'' a waste sample in a way that mimics the leaching of waste 
in a municipal landfill. Thus, TCLP results are a proxy for the 
concentrations of contaminants that would be generated in leachate if 
the waste were placed in a municipal landfill.
---------------------------------------------------------------------------

    \9\ Jury, W.A., W.F. Spencer, and W. J. Farmer. 1983. Behavior 
assessment model for trace organics in soil: i. model description. 
J. Environ. Qual. 12(4):558-564.
    Jury, W.A., W. J. Farmer, and W.F. Spencer. 1984. Behavior 
assessment model for trace organics in soil: ii. chemical 
classification and parameter sensitivity. J. Environ. Qual. 
13(4):567-572.
    Jury, W.A., D. Russo, G. Streile, and H.E. Abd. 1990. Evaluation 
of volatilization by organic chemicals residing below the soil 
surface. Water Resources Research. 26(1):13-20.
---------------------------------------------------------------------------

ii. Tank Emissions Model
    EPA modeled emissions from aerated biological wastewater treatment 
tanks using the CHEMDAT8 model (EPA 1994b 10). We used the 
emissions estimates in conjunction with the air dispersion modeling 
results (see Section D.1.d.iii) to estimate constituent-specific air 
concentrations and deposition rates. CHEMDAT8 accounts for most of the 
competing removal pathways that might limit air emissions, including 
adsorption, biodegradation, and hydrolysis. Chemicals that sorb to 
solids or decompose due to either biodegradation or hydrolysis have 
lower potential for emission to the air. CHEMDAT8 is considered to 
provide reasonable to slightly high estimates of air emissions.
---------------------------------------------------------------------------

    \10\ EPA. 1994b. CHEMDAT8 User's Guide, EPA-453/C-94-080B. 
Office of Air Quality Planning and Standards, US Environmental 
Protection Agency, Research Triangle Park, NC, November. This model 
is publicly available from EPA's Web page at http://www.epa.gov/ttn/
chief/software.html.
---------------------------------------------------------------------------

    CHEMDAT8 requires that the user specify parameters relating to tank 
characteristics, waste characteristics, contaminant physical and 
chemical properties, and location-specific meteorological conditions 
(for example, windspeed and temperature). The tank characterization 
data required by the model include both tank physical parameters (for 
example, tank dimensions) and tank operating parameters (for example, 
the number of aerators in the tank). In the absence of site-specific 
data, we developed tank dimensions based on facility-reported 
wastewater generation rates, an assumed wastewater depth in the tank of 
15 feet, and a retention time in the tank of two days. We selected 
operating parameters that we believe represent typical operating 
conditions of an aerated tank. The Risk Assessment Technical Background 
Document for the Chlorinated Aliphatics Listing Determination provides 
a complete list of the parameters used in the CHEMDAT8 model.
iii. Air Dispersion and Deposition Model
    We used EPA's Industrial Source Complex Short Term model (version 
3;

[[Page 46487]]

ISCST3 11) to estimate the dispersion and deposition of 
vapors emitted from the wastewater treatment tank, the municipal 
landfill, the onsite industrial landfill, and the land treatment unit. 
EPA also used ISCST3 to estimate the dispersion and deposition of 
particulate emissions from the land treatment unit. For the land 
treatment unit, EPA used equations documented in EPA's ``Compilation of 
Air Pollutant Emission Factors (AP-42)'' (EPA 1985) 12 to 
estimate particulate emissions resulting from wind erosion and tilling 
activities. Vapor emissions from the landfill and the land treatment 
unit were estimated using the partitioning models discussed in Section 
III.D.1.d.i. Vapor emissions from the wastewater treatment tank were 
estimated using the CHEMDAT8 model discussed in Section III.D.1.d.ii. 
ISCST3 was used to estimate the air concentration of vapors, wet 
deposition of vapors, the air concentration of particulates, wet 
deposition of particulates, and dry deposition of particulates. We 
calculate dry deposition of vapors using the air concentration of 
vapors and a contaminant deposition velocity.
---------------------------------------------------------------------------

    \11\ EPA. 1995. User's Guide for the Industrial Source Complex 
(ISC3) Dispersion Models (Draft) (Revised). Volume I. EPA-454/B-95-
003a. Office of Air Quality Planning and Standards, Emissions, 
Monitoring and Analysis Division, Research Triangle Park, NC. The 
ISCST3 model and meteorological preprocessor, PCRAMMET, and related 
user's guides can be accessed and downloaded through the Internet 
from the Support Center for Regulatory Air Models (SCRAM) web page 
(http://www.epa.gov/scram001). The SCRAM is part of EPA's Office of 
Air Quality Planning and Standards (OAQPS) Technology Transfer 
Network (TTN).
    \12\ EPA. 1985. Compilation of Air Pollutant Emission Factors, 
AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources. 
Office of Air Quality Planning and Standards, Emissions Inventory 
Group, Research Triangle Park, NC. AP-42 can be downloaded through 
the Internet at http://www.epa.gov/ttn/chief/ap42.html.
---------------------------------------------------------------------------

iv. Overland Transport Model
    The Universal Soil Loss Equation (USLE) is an erosion model 
originally designed to estimate long-term average soil erosion losses 
to a nearby surface water body from an agricultural field having 
uniform slope, soil type, vegetative cover, and erosion-control 
practices. We used a modified form of the USLE to estimate the mass of 
soil lost per year per unit area from the land treatment unit and 
deposited directly onto the adjacent receptor site (agricultural field, 
residential lot, home garden) and into a nearby stream.
    Because the basic USLE equation estimates only soil erosion to 
surface water bodies, EPA assumes the receptor location is located 
between the land treatment unit and the surface water body. The area 
including the land treatment unit, the receptor site, and the 
intervening area is considered for the purposes of the analysis to be 
an independent, discrete drainage subbasin that is at steady-state. We 
estimate the soil erosion load from the subbasin to the surface water 
body using a distance-based sediment delivery ratio, and consider that 
the sediment not reaching the surface water body is deposited evenly 
over the area of the subbasin. Using mass balance equations, EPA 
estimates contaminant contributions to the surface water body and the 
receptor soil. ``Mass balance equations'' are equations that honor the 
law of conservation of mass, that is, the mass of a contaminant that is 
present at the beginning of the analysis (for example, the mass of a 
contaminant in a waste placed in a waste management unit) is equal to 
the mass of the contaminant present at the end of the analysis. Even 
though at the end of the analysis the contaminant mass may be 
partitioned into a number of environmental ``compartments'' (for 
example, the waste management unit, the soil, and the surface water 
body), there is in total no more or no less mass than was present at 
the start of the analysis.
    Contaminated particles are transported from the land treatment unit 
to receptor sites via air deposition as well as runoff/erosion. We 
applied mass balance for each area of interest (for example, buffer 
area between source and receptor site, receptor site, or surrounding 
area). Consequently, the respective air deposition value for each area 
of interest is included in the evaluation of the mass balance. We 
considered that the air deposition over the entire subbasin area is 
uniform and equal to the air deposition modeled for the receptor site.
v. Groundwater Model
    We used EPA's Composite Model for Leachate Migration with 
Transformation Products (EPACMTP; EPA 1996a, 1996b, 1996c, 1997 
13) to model the subsurface fate and transport of 
contaminants that leach from the waste management units (the land 
treatment unit or the landfill) and migrate to a residential drinking 
water well or discharge from groundwater to surface water.
---------------------------------------------------------------------------

    \13\ EPA. 1996a. EPA's Composite Model for Leachate Migration 
with Transformation Products (EPACMTP) Background Document. Office 
of Solid Waste, Washington, DC.
    EPA. 1996b. EPA's Composite Model for Leachate Migration with 
Transformation Products (EPACMTP) Background Document for the Finite 
Source Methodology. Office of Solid Waste, Washington, DC.
    EPA. 1996c. EPA's Composite Model for Leachate Migration with 
Transformation Products (EPACMTP) Background Document for Metals. 
Office of Solid Waste, Washington, DC.
    EPA. 1997. EPA's Composite Model for Leachate Migration with 
Transformation Products (EPACMTP) User's Guide. Office of Solid 
Waste, Washington, DC.
---------------------------------------------------------------------------

    Precipitation that migrates through the waste management unit 
generates leachate, which infiltrates the bottom of the waste 
management unit and migrates into the unsaturated zone. The 
contaminants dissolved in the leachate subsequently are transported in 
the aqueous phase through the unsaturated zone to the underlying 
saturated zone and then downgradient to a receptor (drinking water) 
well or surface water body located at a specified distance from the 
boundary of the waste management unit. EPACMTP accounts for the 
following processes affecting contaminant fate and transport: 
advection, hydrodynamic dispersion, equilibrium linear or nonlinear 
sorption by the soil and aquifer solids (both in the unsaturated and 
saturated zones), and contaminant hydrolysis. In the event that the 
hydrolysis daughter products are toxic and their chemical properties 
are known, the model also accounts for the formation and subsequent 
fate and transport of the daughter products.
    The landfill analysis employed two simplifying assumptions. First, 
we assumed that contaminant leaching from the landfill does not occur 
until after the landfill closes (that is, after 30 years). EPA made 
this assumption because of complexities associated with linking the 
output of the landfill partitioning equations (discussed in Section 
III.D.1.d.i.) and the groundwater model, EPACMTP. Second, we assumed 
that there are no contaminant losses due to mechanisms other than 
leaching after the landfill has been closed (that is, after 30 years). 
This effectively over-estimates the total mass of volatile contaminants 
that would leach to groundwater because it does not allow contaminant 
loss due to volatilization from the landfill to deplete the total 
contaminant mass available for leaching from the landfill in the years 
after closure. EPA determined that if volatile constituents caused 
significant risk via the groundwater pathway, we would have to re-
evaluate our methodology for conducting the landfill analysis. This 
situation did not occur.
vi. Surface Water Model
    EPA assumed that fish are exposed to waste constituents in surface 
water. Specifically, we assumed that fish are exposed to contaminants 
dissolved in the water column, contaminants sorbed to suspended solids 
in the water

[[Page 46488]]

column, and contaminants associated with the bed sediment in the 
surface water body. The method used to estimate how management of 
chlorinated aliphatics wastewaters and wastewater treatment sludges 
impacts surface water is based on the methodology presented in Addendum 
to Methodology for Assessing Health Risks Associated with Indirect 
Exposure to Combustor Emissions (EPA 1993) 14. The model 
accounts for six ways in which contaminants may enter the surface water 
body: (1) contaminants may be sorbed to eroded soils that enter the 
surface water body, (2) contaminants may be dissolved in runoff that 
enters the surface water body, (3) contaminants may be bound to 
airborne particles that are deposited on the surface water body, (4) 
vapor phase contaminants in air may be deposited on the surface water 
body in precipitation (that is, wet deposition of vapor phase 
contaminants), (5) vapor phase contaminants in air may enter the 
surface water body through direct diffusion from the air, and (6) 
contaminants in groundwater may discharge into the surface water body. 
The model also accounts for processes that remove contaminants from the 
surface water body. These include: (1) volatilization of contaminants 
that are dissolved in surface water and (2) burial of contaminants in 
the sediment at the bottom of the surface water body. The model assumes 
that the impact to the water body is uniform, which is more realistic 
for smaller surface water bodies than for larger ones. The model 
estimates the concentrations of contaminants in the water column and 
bed sediment. We used the water column or bed sediment concentrations 
and bioconcentration factors (BCFs), bioaccumulation factors (BAFs), or 
biota-sediment accumulation factors (BSAFs) to estimate contaminant 
concentrations in fish tissue.
---------------------------------------------------------------------------

    \14\ EPA. 1993. Addendum to Methodology for Assessing Health 
Risks Associated with Indirect Exposure to Combustor Emissions. EPA/
600/AP-93003. Office of Health and Environmental Assessment, 
Washington, DC.
---------------------------------------------------------------------------

vii. Indirect Exposure Equations
    EPA uses a series of ``indirect exposure equations'' to quantify 
the concentrations of contaminants that pass indirectly from 
contaminated environmental media to the receptor. For example, 
contaminants that are transported in air may be deposited on plants or 
onto the soil where they may accumulate in forage, grain, silage or 
soil that is consumed by beef cattle and dairy cattle. Individuals may 
then ingest contaminated beef and dairy products. Similarly, 
contaminants may be transported in groundwater to domestic groundwater 
wells where the groundwater is extracted and used for showering. The 
water vapor generated in the shower may be inhaled by the receptor. The 
indirect exposure equations allow EPA to calculate exposure point 
concentrations for these pathways and routes of exposure. The indirect 
exposure equations used by EPA to conduct the chlorinated aliphatic 
wastewater, EDC/VCM sludge, and methyl chloride sludge risk assessments 
are presented in the Risk Assessment Technical Background Document for 
the Chlorinated Aliphatics Listing Determination.
e. How Did EPA Quantify Contaminant Exposure and Toxicity?
    Exposure is the condition that occurs when a contaminant comes into 
contact with the outer boundary of the body, such as the skin, mouth 
and nostrils. Once EPA establishes the concentrations of contaminants 
at the points of exposure, EPA can estimate the magnitude of each 
receptor's exposure, or the contaminant dose. Dose is the amount of the 
contaminant that crosses the outer boundary of the body and is 
available for absorption at internal exchange boundaries (lungs, gut, 
skin; EPA 1992 15). For example, for exposure to a 
carcinogen through ingestion of contaminated drinking water, dose is a 
function of the concentration of the contaminant in drinking water (the 
exposure point concentration), as well as certain ``exposure factors,'' 
such as how much drinking water the receptor consumes each day (the 
intake rate), the number of years the receptor is exposed to 
contaminated drinking water (the exposure duration), how often the 
receptor is exposed to contaminated drinking water (the exposure 
frequency), the body weight of the receptor, and the period of time 
over which the dose is averaged.
---------------------------------------------------------------------------

    \15\ 57 FR 22888. Final Guidelines for Exposure Assessment. U.S. 
Environmental Protection Agency, May 29, 1992.
---------------------------------------------------------------------------

    EPA's primary source of exposure factors is the ``Exposure Factors 
Handbook'' published by EPA in August 1997 (EPA 1997a 16). 
For probabilistic risk analyses, EPA used the distributions of exposure 
factor values provided in the Exposure Factors Handbook to develop PDFs 
for exposure factors. The one situation where EPA does not develop an 
expression of dose is the case where we use Reference Concentrations 
(RfCs) 17 to estimate noncancer hazard for the inhalation 
exposure route. In this situation, EPA calculates noncancer hazard from 
concentration of the contaminant in air and the RfC, without 
considering exposure factors (inhalation rate, body weight) other than 
those inherent in the RfC.
---------------------------------------------------------------------------

    \16\ EPA. 1997a. Exposure Factors Handbook, Volumes I, II, and 
III. Office of Research and Development, Washington, D.C., EPA/600/
P-95/002Fa, b, c. August 1997, www.epa.gov/ordntrnt/ord/webpubs/
exposure/index.html.
    \17\ Very simply, an RfC is EPA's acceptable concentration in 
air for a contaminant that causes non-cancer health effects. An RfC 
is an estimate (with uncertainty spanning perhaps an order of 
magnitude) of a continuous inhalation exposure to the human 
population (including sensitive subgroups) that is likely to be 
without an appreciable risk of deleterious noncancer effects during 
a lifetime.
---------------------------------------------------------------------------

    We express the toxicity of contaminants as health benchmarks. 
Health benchmarks include cancer slope factors (CSFs, EPA's measure of 
cancer potency) 18 for oral exposure carcinogenic 
contaminants; reference doses (RfDs, EPA's acceptable contaminant dose 
via ingestion) 19 for oral exposure to noncarcinogenic 
contaminants; inhalation CSFs for inhalation exposure to carcinogenic 
contaminants; and RfCs for inhalation exposure to noncarcinogenic 
contaminants. EPA derived inhalation CSFs from Unit Risk Factors (URFs) 
for inhalation exposure to carcinogens. EPA uses Toxicity Equivalency 
Factors (TEFs) to express the toxicity of specific dioxin congeners in 
terms of the toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-
TCDD) (see Section III. D.1.g.ii. for an explanation of TEFs). Health 
benchmark values are available from a number of sources. For the 
chlorinated aliphatics wastewater, EDC/VCM sludge, and methyl chloride 
sludge risk assessments, EPA established an order of preference for the 
sources of health benchmarks. The order of preference is as follows 
(from most preferred to least preferred): (1) the Integrated Risk 
Information System (IRIS) online database of verified health benchmarks 
(http://www.epa.gov/iris/subst/index.html) 20; (2) the 
Health Effects Assessment Summary Tables (HEAST;

[[Page 46489]]

EPA 1997b) 21; (3) EPA's National Center for Environmental 
Assessment (NCEA) provisional values, and (3) benchmarks developed by 
the California Environmental Protection Agency (CALEPA) 22. 
The specific health benchmarks used in the analysis are presented in 
Appendix C of the Background Document for the Chlorinated Aliphatics 
Risk Assessment.
---------------------------------------------------------------------------

    \18\ A cancer slope factor is the slope of the dose-response 
curve in the low-dose region. When low-dose linearity cannot be 
assumed, the slope factor is the slope of the straight line from 0 
dose (and 0 excess risk) to the dose at 1% excess risk. An upper 
bound on this slope is usually used instead of the slope itself. The 
units of the slope factor usually are expressed as 1/(mg/kg-day).
    \19\ An RfD is an estimate (with uncertainty spanning perhaps an 
order of magnitude) of a daily exposure to the human population 
(including sensitive subgroups) that is likely to be without an 
appreciable risk of deleterious effects during a lifetime.
    \20\ EPA. 1998. Integrated Risk Information System. Online 
database. (IRIS) Office of Research and Development (ORD). 
Cincinnati, OH.
    \21\ EPA. 1997b. Health Effects Assessment Summary Tables: 
Annual Update. (HEAST) Office of Emergency and Remedial Response. 
Washington, D.C. July.
    \22\ California Environmental Protection Agency (CalEPA). 1997. 
Air Toxics Hot Spots Program Risk Assessment Guidelines: Technical 
Support Document for Determining Cancer Potency Factors. Draft for 
Public Comment. Office of Environmental Health Hazard Assessment, 
Berkeley, CA, www.oehha.org/ra__guidance/.
---------------------------------------------------------------------------

f. What Are the Risks From Exposure to Chlorinated Aliphatics 
Wastewaters, and EDC/VCM and Methyl Chloride Sludges?
    The following sections discuss EPA's estimates of individual and 
population risk for chlorinated aliphatics wastewaters, EDC/VCM 
sludges, and methyl chloride sludges.
i. What Are the Individual Risks?
    EPA combined estimates of dose and estimates of toxicity (the 
health benchmarks) to calculate individual incremental lifetime 
carcinogenic risk estimates and hazard quotients for the potential 
contaminants of concern in chlorinated aliphatic wastewaters, EDC/VCM 
sludge, and methyl chloride sludge. Complete results of these 
calculations are provided in the Risk Assessment Technical Background 
Document for the Chlorinated Aliphatics Listing Determination. EPA 
typically considers a decision to list a waste when carcinogenic risks 
are 1x10-5 or greater or when the noncancer HQ is 1 or 
greater. None of the contaminants generated noncancer hazards with an 
HQ greater than 1, nor did the sum of the contaminant HQs exceed 1. In 
summing carcinogenic risk estimates and noncancer hazard quotients, EPA 
does not sum those risks or hazards that could not occur within the 
lifetime of an individual. For example, if estimated risks due to 
nongroundwater pathways occur during the operating or post-closure life 
of the unit (that is, due to releases to air and runoff/erosion) and 
risk via the groundwater pathways are not projected to occur for 
hundreds, or even thousands, of years due to long times required for 
contaminant migration, then these two pathway risks would not be added 
together.
    The following sections present separately our deterministic and 
probabilistic estimates of individual risk for:
     Wastewaters from the production of chlorinated aliphatic 
chemicals,
     Wastewater treatment sludges from the production of EDC/
VCM, and
     Wastewater treatment sludges from the production of methyl 
chloride.

Chlorinated Aliphatic Wastewaters

    Table III-1 summarizes the significant (greater than 
1x10-5 risk estimates for chlorinated aliphatic wastewaters 
managed in onsite aerated biological wastewater treatment tanks. The 
highest deterministic risk estimate, 2x10-5, occurs for the 
farmer. The risk is attributable to the farmer's ingestion of dioxins, 
which in Table III-1 are expressed as the 2,3,7,8-tetrachlorodibenzo-p-
dioxin (TCDD) toxicity equivalent (TEQ). The farmer's high end 
deterministic risk falls slightly below the 90th percentile 
probabilistic risk estimate (the 80th percentile risk estimate is 
1x10-5). Table III-2 summarizes our deterministic estimates 
of risk due to the direct inhalation of chloroform. The high end 
chloroform risks are 3x10-6 for the farmer and 
2x10-6 for all other receptors. The chloroform deterministic 
risk estimates for the adult receptors are roughly equal to the 97.5th 
percentile probabilistic risk estimates. Although the chloroform risks 
are not greater than 1x10-5, they are additive to the risks 
that EPA estimated for dioxins because they would occur within the same 
timeframe.

BILLING CODE 6560-50-P

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EDC/VCM Sludges

    Tables III-3 and III-4 summarize the significant (greater than 
1x10-5) risk estimates for EDC/VCM wastewater treatment 
sludges managed in an onsite land treatment unit. In all cases, we 
estimated that the highest risk occurs for the farmer. Table III-3 
presents dioxin (expressed as 2,3,7,8-TCDD TEQ) risk estimates for the 
land treatment unit nongroundwater pathways. The high end deterministic 
risk estimate for the farmer is 2x10-4, which also 
corresponds to the 95th percentile probabilistic risk 
estimate. Table III-4 presents arsenic risk estimates for the land 
treatment unit groundwater pathways. The high end deterministic risk 
estimate for the farmer is 1x10-5, which falls between the 
97.5th percentile probabilistic risk estimate 
(6x10-6) and the 100th percentile probabilistic 
risk estimate (5x10-5). EPA estimates that the groundwater 
pathway risks in Table III-4 would occur approximately 1500 years in 
the future, whereas the dioxin nongroundwater pathway risks in Table 
III-3 would occur during the assumed operating life of land treatment 
unit. Table III-5 summarizes the significant risk estimates for EDC/VCM 
sludges managed in an offsite municipal landfill. The risk estimates 
presented in Table III-5 are arsenic groundwater pathway risks. The 
high end deterministic risk estimate for the farmer is 
3x10-5, which falls between the 97.5th percentile 
(1x10-5) and 100th percentile (3x10-4) 
probabilistic risk estimates. We estimate that the arsenic risks 
attributable to the landfill (presented in Table III-5) would occur 
thousands of years in the future.

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BILLING CODE 6560-50-C

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Methyl Chloride Sludges

    EPA conducted a deterministic analysis to estimate nongroundwater 
(air) pathway risks associated with management of methyl chloride 
sludges in an onsite landfill. All nongroundwater pathway carcinogenic 
risks were less than 1  x 10-8, and all noncancer HQs were 
less than 0.0001.
    For groundwater pathways, EPA performed a screening analysis that 
maximizes estimates of risk or hazard to human receptors. EPA 
calculated the carcinogenic risk for an adult who ingests (drinks) 1.4 
liters of leachate from the landfill for 350 days per year for 58 
years. EPA also calculated the noncancer hazard for a child who ingests 
1.4 liters of leachate from the landfill for 350 days per year for 9 
years. None of the noncancer HQs was greater than 1. Arsenic was the 
only carcinogen with risk in excess of 1  x 10-5. 
Specifically, an adult's risk due to ingesting leachate from methyl 
chloride sludges for 58 years was 5  x 10-5 due to arsenic. 
EPA discusses our evaluation of this risk in Section III.E.4.b.
ii. What are the Population Risks?
    EPA expects that the population risks resulting from management of 
chlorinated aliphatics wastewaters in tanks and EDC/VCM sludges in 
onsite land treatment units and landfills are not significant. With 
regard to groundwater pathway risks, EPA believes that the number of 
domestic drinking water wells (thus the population) potentially 
affected by groundwater contaminated with arsenic originating from the 
landfill and the land treatment unit would be very small. Furthermore, 
we estimate that the arsenic concentrations predicted in receptor 
(drinking water) wells will result in risks only slightly above 1  
x 10-5 for that very small number of people.
    For nongroundwater pathways, EPA performed a screening evaluation 
of population risk for the waste management scenario and pathway that 
resulted in the greatest individual risk estimate of any pathway 
evaluated in the chlorinated aliphatics risk assessment. Specifically, 
EPA evaluated risk associated with ingestion of beef and dairy products 
contaminated with dioxins derived from the onsite EDC/VCM land 
treatment unit. As presented previously, under the land treatment unit 
scenario the farmer's total individual excess lifetime cancer risk from 
ingestion of beef and dairy was 2  x 10-4 for high end 
exposures and 3  x 10-6 for central tendency exposures. 
Although the individual risk estimates for the farmer exposed to 
dioxins from EDC/VCM sludge managed in a land treatment unit are an 
order of magnitude greater than those for the farmer exposed to dioxins 
from chlorinated aliphatics wastewaters managed in tanks, is possible 
that population risks resulting from releases from chlorinated 
aliphatics wastewaters would exceed those resulting from releases from 
EDC/VCM sludges. This might occur because there is only one land 
treatment unit that is used to manage EDC/VCM sludge, and we expect 
that there may be many aerated biological wastewater treatment tanks 
used to manage chlorinated aliphatics wastewaters. Nevertheless, EPA 
believes that it is reasonable to assume that the population risks for 
the land treatment unit likely would be greater than those for the 
wastewater tanks because there would need to be at least 10 wastewater 
treatment tanks with surrounding cattle populations similar to that of 
the land treatment unit to produce a population risk estimate 
equivalent to that of the land treatment unit.
    Results of the population risk analysis for the land treatment unit 
indicate that 2  x 10-4 excess cancer cases would be 
expected annually in a population of 1,410 individuals ingesting beef 
produced from cattle raised within 2 kilometers of the land treatment 
unit over a 40-year operational life for the land treatment unit (dairy 
cattle are not raised in the county where the land treatment unit is 
located, thus we did not evaluate ingestion of dairy products in the 
population risk analysis). The average individual risk to the 
population consuming beef from within the 2-kilometer radius is 2  
x 10-7. We calculated the population potentially affected by 
a release from the land treatment unit (1,410 individuals) from the 
total estimated quantity of contaminated beef and average beef 
ingestion rates (that is, we calculated how many people would be 
required to consume all of the contaminated beef assuming typical rates 
of beef ingestion). It is possible that the contaminated beef would be 
distributed more widely throughout the population, such that the total 
number of people ingesting the contaminated beef would be greater than 
1,410. However, the population risk estimate would not change because 
population risk is a function of the number of people who are exposed 
(that is, consume contaminated beef) and each person's individual risk 
(which is a function of the amount of contaminated beef a person 
consumes). Consequently, as the number of people who are exposed 
increases, the individual risk must decrease proportionally because 
there is only a finite amount of contaminated beef, and the overall 
population risk remains the same. The Risk Assessment Technical 
Background Document for the Chlorinated Aliphatics Listing 
Determination provides a description of the procedure used to estimate 
population risks.
    EPA did not estimate population risks for the other receptors for 
whom we calculated individual risk estimates (residents, children, 
gardeners, and fishers). Because the high end risk for the land 
treatment unit scenario was driven by the ingestion of beef and dairy 
products, the population risks for non-farmer receptors are expected to 
be considerably lower than 2  x 10-4.
    Although the population risks attributable to the management of 
chlorinated aliphatics wastes are expected to be very small, EPA does 
not believe it is appropriate to allow contamination from waste 
management activities to cause substantial risk to nearby residents 
simply because there are few individuals in the immediate vicinity of 
the waste management units. 40 CFR 261.11 clearly states that wastes 
are to be listed if they are ``capable of posing a substantial present 
or potential hazard.'' It does not state that a large number of people 
must be affected. However, population risk may be a factor that the 
Agency could consider under 40 CFR 261.11(a)(3)(xi) (``other factors as 
may be appropriate'').
    EPA's Guidance for Risk Characterization (EPA 1995) states that 
when small populations are exposed, population risk estimates may be 
very small, however, ``in such situations, individual risk estimates 
will usually be a more meaningful parameter for decision-makers.'' 
Consequently, EPA's decision to list wastes has been based primarily on 
the concern over risks to those individual's who are significantly 
exposed, even if there are relatively few such individuals. EPA, 
however, requests comment on whether it would be appropriate to give 
weight to population risk in deciding whether to list these chlorinated 
aliphatic wastes as hazardous. EPA further invites comment on the 
effect of this approach on the Agency's goals with respect to 
environmental justice in rural areas.
g. What Is the Toxicity of COCs Identified by EPA?
    The two contaminants for which EPA calculated significant risks are 
dioxins (expressed as the 2,3,7,8-TCDD TEQ) and arsenic. The following 
sections discuss the ways that these contaminants affect human health.

[[Page 46497]]

i. Arsenic
    Arsenic is a naturally occurring element in the earth's crust that 
usually exists as an inorganic or organic compound, rather than in a 
free state. Arsenic that exists in compounds with elements such as 
oxygen, chlorine, and sulfur is referred to as inorganic arsenic; 
arsenic combined with carbon is referred to as organic arsenic. Organic 
forms of arsenic are less toxic than inorganic forms.
    There is clear evidence that chronic exposure to inorganic arsenic 
in humans increases the risk of cancer, and EPA classifies inorganic 
arsenic as a Group A--Known Human Carcinogen. Studies report that 
inhalation of arsenic results in an increased risk of lung cancer. In 
addition, ingestion of arsenic has been associated with an increased 
risk of nonmelanoma skin cancer and bladder, liver, kidney, and lung 
cancer. No information is available on the risk of cancer in humans 
from dermal exposure to arsenic (EPA 1998).
ii. Dioxins
    2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) belongs to the 
class of compounds, chlorinated dibenzo-p-dioxins and chlorinated 
dibenzofurans, that are referred to as dioxins. EPA issued a draft 
Health Assessment Document for 2,3,7,8-TCDD and Related Compounds in 
1994. This document is a three-volume series consisting of a complete 
reassessment of the toxic effects of 2,3,7,8-TCDD (EPA 1994a, b \23\). 
The document was reviewed by EPA's Science Advisory Board (SAB) but has 
not yet been issued in final form.
---------------------------------------------------------------------------

    \23\ EPA. 1994a. Health Assessment Document for 2,3,7,8-
Tetrachlorodibenzo-p-Dioxin (TCDD) and Related Compounds. Volume II. 
(Draft). Office of Research and Development, Washington, D.C., 
www.epa.gov/ord/health.
    EPA. 1994b. Health Assessment Document for 2,3,7,8-
Tetrachlorodibenzo-p-Dioxin (TCDD) and Related Compounds. Volume 
III. (Draft). Office of Research and Development, Washington, D.C., 
www.epa.gov/ord/health.
---------------------------------------------------------------------------

    EPA has classified 2,3,7,8-TCDD as a Group B2--Probable Human 
Carcinogen (EPA 1997b). An increase in lung cancer risks was observed 
among Japanese males exposed to 2,3,7,8-TCDD as a result of an oil 
poisoning accident. Human studies have also found an association 
between 2,3,7,8-TCDD and soft-tissue sarcomas, lymphomas, and stomach 
carcinomas, although for malignant lymphomas, the increase in risk is 
not consistent. The increase in risk is of borderline significance for 
highly exposed groups and is less among groups exposed to lower levels 
of 2,3,7,8-TCDD (EPA 1994b). In animal tests, TCDD is one of the most 
potent carcinogens ever evaluated.
    Although EPA has not developed an RfD or an RfC for 2,3,7,8-TCDD, 
noncarcinogenic health effects have been reported for 2,3,7,8-TCDD. The 
major noncarcinogenic effect from exposure to 2,3,7,8-TCDD is 
chloracne, a severe acne-like condition that develops within months of 
first exposure to high levels of 2,3,7,8-TCDD. For many individuals, 
the condition disappears after discontinuation of exposure, for others 
it may remain for years. There are limited human data to suggest the 
doses at which chloracne is likely to occur (EPA 1994a, b). 
Epidemiological studies report conflicting evidence on the 
immunotoxicity of 2,3,7,8-TCDD in humans. Some studies suggest evidence 
of immunotoxicity, such as alterations in lymphocyte populations, cell 
surface markers, or lymphocyte proliferative response (ATSDR 1997c 
\24\). However, studies have not reported changes in the immune system 
directly related to 2,3,7,8-TCDD exposure (EPA 1994a, b). An 
association has been reported between levels of male reproductive 
hormones and 2,3,7,8-TCDD exposure. Decreased testosterone levels were 
detected in several human studies, and animal data are available to 
support these findings. Other effects noted in human studies include an 
association between 2,3,7,8-TCDD exposure and the following:
---------------------------------------------------------------------------

    \24\ ATSDR (Agency for Toxic Substances and Disease Registry). 
1997c. Toxicological Profile for 2,3,7,8-Tetrachlorodibenzo-p-
dioxin. U.S. Public Health Service, U.S. Department of Health and 
Human Services, Atlanta, GA.
---------------------------------------------------------------------------

     An increased risk of diabetes and an elevated prevalence 
of abnormal fasting serum glucose levels
     The induction of cytochrome P-450 1A1, an enzyme involved 
in biotransformation reactions
     Elevation of gamma glutamyl transferase, a liver enzyme
     A possible increased risk of endometriosis, a disease of 
the female reproductive system (EPA 1994a, b).
    Animal studies report reproductive and developmental effects from 
exposure to 2,3,7,8-TCDD. These studies suggest that altered 
development may be among the most sensitive endpoints of 2,3,7,8-TCDD 
exposure. Developmental toxicity has been reported to occur in several 
animal species at lower levels than male and female reproductive 
toxicity effects. 2,3,7,8-TCDD appears to affect a large number of 
critical developmental effects at specific developmental stages. These 
changes can lead to increases in fetal mortality, disruption of organ 
system structure, and irreversible impairment of organ function. 
Developmental toxicity from 2,3,7,8-TCDD has been seen in fish, birds, 
and mammals (EPA 1994a, b).
    EPA assigned 17 dioxin and furan congeners individual toxicity 
equivalency factors (TEFs). TEFs are estimates of the toxicity of 
dioxin-like compounds relative to the toxicity of TCDD, which is 
assigned a TEF of 1.0. We used the TEFs identified as the I-TEFs 
(International-TEFs) to conduct the chlorinated aliphatics risk 
assessment because, until very recently, this is the TEF scheme EPA 
scientists have recommended and used for the last 10 years (EPA 1989) 
\25\ \26\. Documentation supporting the use of the TEFs has been placed 
in the rulemaking record.
---------------------------------------------------------------------------

    \25\ EPA. 1989. Interim Procedures for Estimating Risks 
Associated with Exposure to Mixtures of Chlorinated Dibenzo-p-
Dioxins and Furans (CDDs and CDFs) and 1989 Update. EPA/625/3-89/
016. Risk Assessment Forum. March.
    \26\ Proposed Rule, ``Addition of Dioxin and Dioxin-Like 
Compounds; Modification of Polychlorinated Biphenyls (PCBs) Listing; 
Toxic Chemical Release Reporting; Community Right-to-Know,'' 62 FR 
24887, (May 7, 1997).
---------------------------------------------------------------------------

    The I-TEFs are presented in Table III-6. The I-TEFs are based on a 
limited data base of in vivo and in vitro toxicity testing (EPA 1989). 
The World Health Organization (WHO) recently reviewed the I-TEFs (Van 
den Berg et al. 1998) \27\, and determined that three of the I-TEFs, 
those for 1,2,3,7,8-PeCDD (pentachlorodibenzo-p-dioxin), OCDD 
(octachlorodibenzo-p-dioxin), and OCDF (octachlorodibenzofuran), 
required modification (Table III-6). EPA is in the process of adopting 
these modifications, and consequently reviewed the impact that the 
revised (WHO-) TEFs would have on the results of the chlorinated 
aliphatics risk assessment. 1,2,3,7,8-PeCDD was not detected in 
dedicated chlorinated aliphatic wastewaters, dedicated EDC/VCM sludges, 
or methyl chloride sludges. Consequently, the difference in the I-TEF 
and the WHO-TEF for 1,2,3,7,8-PeCDD has no impact on the results of the 
risk analyses presented in this section. Because of the TEF differences 
for OCDD and OCDF, however, the decision to use either the I-TEFs or 
the WHO-TEFs potentially may result in large differences in the 
calculated TCDD TEQ concentrations for a given chlorinated aliphatics 
waste sample. Nevertheless, because OCDD and OCDF contribute very 
little to the actual risk attributable to dioxin compounds, the 
decision to use either

[[Page 46498]]

the I-TEFs or the WHO-TEFs has negligible impact to the overall risk 
results. The Risk Assessment Technical Background Document for the 
Chlorinated Aliphatics Listing Determination provides separate risk 
results for each of the dioxin congeners detected in the wastewaters 
and sludges evaluated.
---------------------------------------------------------------------------

    \27\ Van den Berg, et al. 1998. Toxic Equivalency Factors (TEFs) 
for PCBs, PCDDs, PCDFs for Humans and Wildlife. Environmental Health 
Perspectives, v.106, n.12, pp. 775-792. December.

  Table III-6. Toxicity Equivalency Factors (TEFs) for Dioxin Compounds
------------------------------------------------------------------------
                Compound                   I-TEF          WHO-TEF
------------------------------------------------------------------------
2,3,7,8-TCDD............................   1       same
1,2,3,4,5,7,8,9-OCDD....................   0.001   0.0001
1,2,3,7,8,9-HxCDD.......................   0.1     same
1,2,3,4,6,7,8-HpCDD.....................   0.01    same
1,2,3,4,6,7,8,9-OCDF....................   0.001   0.0001
1,2,3,4,7,8-HxCDD,......................   0.1     same
1,2,3,7,8-PeCDD,........................   0.5     1
2,3,7,8-TCDF............................   0.1     same
1,2,3,4,7,8,9-HpCDF.....................   0.01    same
2,3,4,7,8-PeCDF.........................   0.5     same
1,2,3,7,8-PeCDF.........................   0.05    same
1,2,3,6,7,8-HxCDF.......................   0.1     same
1,2,3,6,7,8-HxCDD.......................   0.1     same
2,3,4,6,7,8-HxCDF.......................   0.1     same
1,2,3,4,6,7,8-HpCDF.....................   0.01    same
1,2,3,4,7,8-HxCDF.......................   0.1     same
1,2,3,7,8,9-HxCDF.......................   0.1     same
------------------------------------------------------------------------

h. What Is the Uncertainty in the Human Health Risk Results?
    EPA typically classifies the major areas of uncertainty in risk 
assessments as parameter uncertainty, scenario uncertainty, and model 
uncertainty. This section identifies the primary sources of each of 
these types of uncertainty in the chlorinated aliphatics risk 
assessment, and qualitatively describes how each may influence the 
results of the risk assessment.
    Many of the parameters that we used to quantify contaminant fate 
and transport and contaminant exposure and dose either were not 
measured or could not be measured precisely and/or accurately. Some of 
the most important and sensitive parameters in our analyses include 
those that describe waste composition; waste management practices; site 
characteristics (for example, hydrogeological, topographical, 
meteorological, and soils data); the physiologic and behavioral 
exposure characteristics of the receptors; the physical, chemical, and 
biochemical properties of the contaminants; and toxicological effects. 
We believe that the primary sources of parameter uncertainty include 
the following:

     The risk analyses were based on a limited set of waste 
sample data. It is possible that these data do not represent the 
true distribution of contaminant concentrations in the waste 
categories evaluated, resulting in either an overestimation or 
underestimation of the actual risk to receptors.
     EPA obtained little site-specific information regarding 
waste management units for the chlorinated aliphatics industry, 
necessitating that we make a number of assumptions regarding waste 
management in off-site landfills, the land treatment unit, and 
wastewater tanks. Many of the facilities reported using offsite 
nonhazardous landfills to dispose of EDC/VCM sludges. We assumed 
that these landfills are municipal landfills, and modeled typical 
municipal landfills based on available data. Our major assumptions 
about the municipal landfills that have the effect of decreasing our 
risk estimates are that the landfills have daily covers and run-on/
run-off controls. Our major assumptions about the municipal 
landfills that have the effect of increasing our risk estimates are 
that the landfills are not lined and have no leachate collection 
systems. For the land treatment unit, we assumed that no run-on/run-
off controls were present to mitigate risk. We assumed that the 
industry's wastewater treatment tanks are uncovered (which increases 
our risk estimates), are aerated (which increases our risk 
estimates), employ biological treatment techniques (which decreases 
our risk estimates), have structural integrity (which decreases our 
risk estimates), and have spill and overflow controls (which 
decreases our risk estimates).
     We typically used regional databases to obtain the 
parameter values necessary to model contaminant fate and transport. 
Because the data that we used are not specific to the facilities at 
which the actual wastes are managed, the data represent our best 
estimates of actual site conditions. Use of these databases in lieu 
of site-specific data may result in either overestimates or 
underestimates of risk.
     Sources of uncertainty in toxicological benchmarks 
include one or more of the following: extrapolation from laboratory 
animal data to humans, variability of response within the human 
population, extrapolation of responses at high experimental doses 
under controlled conditions to low doses under highly variable 
environmental conditions, and adequacy of the database (number of 
studies available, toxic endpoints evaluated, exposure routes 
evaluated, sample sizes, length of study, etc.). Toxicological 
benchmarks are designed to be conservative (that is, overestimate 
risk) because of the uncertainties and challenges associated with 
condensing toxicity data into a single quantitative expression. 
Therefore, use of the current toxicological benchmarks most likely 
overestimated risk for the pathways evaluated.
     EPA estimated the risk of developing cancer from the 
estimated lifetime average daily dose and the slope of the dose-
response curve. A cancer slope factor is derived from either human 
or animal data and is taken as the upper bound on the slope of the 
dose-response curve in the low-dose region, generally assumed to be 
linear, expressed as a lifetime excess cancer risk per unit 
exposure. However, individuals exposed to carcinogens in the first 
few years of life may be at increased risk of developing cancer. For 
this reason, EPA recognizes that significant uncertainties and 
unknowns exist regarding the estimation of lifetime cancer risks in 
children. We also note that the analysis of cancer risks in children 
has not been externally peer reviewed.

We expect that the various sources of parameter uncertainty in our risk 
assessment counterbalance each other, such that parameter uncertainty 
will not result in a significant overall increase or decrease in risk.
    Scenario uncertainty results from the assumptions we make regarding 
how receptors become exposed to contaminants. This uncertainty occurs 
because of the difficulty and general impracticality of making actual 
measurements of a receptor's exposure. Exposure modeling relies heavily 
on default assumptions regarding population activity patterns, 
mobility, dietary habits, body weights, and other factors. Because the 
risk estimates presented in today's notice are for hypothetical chronic 
exposures and are designed to provide a realistic range of potential 
receptor exposure scenarios, we develop predictions of long-term 
average exposures for each receptor. Although it is possible to study 
various populations to determine their exposure parameters (for 
example, age-specific soil ingestion rates or intake rates for food) or 
to assess past exposures (epidemiological studies) or current 
exposures, risk assessment is about prediction. Therefore, long-term 
exposure monitoring in this context is infeasible. The double-high end 
deterministic approach coupled with the probabilistic approach is 
designed to provide reasonable estimates of potential long-term 
exposures for various receptors. The Exposure Factors Handbook provides 
the current state-of-the-science regarding exposure modeling and 
assumptions and was used in the risk assessment. To the extent that 
actual exposure scenarios vary from the assumptions we used, risks 
could be underestimated or overestimated. Although there could be 
individuals living near a waste disposal site who have higher exposures 
than those presented, it is more likely that actual exposures for most 
of these individuals would fall within the predicted range, and, 
moreover, would be similar to those predicted for the central tendency 
or 50th percentile.
    Models and their mathematical expressions are simplifications of 
reality that are used to approximate real-world conditions and 
processes, and their

[[Page 46499]]

relationships. Models do not include all parameters or equations 
necessary to express reality because of the inherent complexity of the 
natural environment, and the lack of sufficient data to describe the 
natural environment. Consequently, models are based on numerous 
assumptions and simplifications, and reflect an incomplete 
understanding of natural processes. We selected the models used in this 
risk assessment, described in Section III.D.1.d, based on science, 
policy, and professional judgment. We selected the wastewater emissions 
model, the air dispersion and deposition models, the indirect exposure 
equations, and the groundwater model because they provide the 
information needed for this analysis and because we generally consider 
them to be state-of-the-science. Even though the models used in the 
risk analysis are used widely and have been accepted for numerous 
applications, they each retain significant sources of uncertainty that 
as a whole could result in either an overestimation or underestimation 
of risk.
    One of the sources of uncertainty is our assumption that vapor 
emissions of dioxins from chlorinated aliphatics wastewaters and 
wastewater treatment sludges do not appreciably sorb to particulate 
matter in the ambient air in approximately 1.2 minutes, the average the 
time required for emissions from the waste management units to reach a 
receptor located 300 meters away (our central tendency distance to 
receptor). Sorption of dioxins onto particles in air would remove 
dioxins from the vapor phase, thereby reducing the vapor-phase 
diffusion of dioxins into plants. As a result, our calculated dioxin 
concentrations in plants, and in animals consuming plants (particularly 
grasses), are higher than they would be if we assumed that some 
fraction of the vapor phase dioxin irreversibly partitions onto 
particles in the ambient air. However, given the uncertainties 
regarding rates of dioxin partitioning, magnitude of partitioning, and 
other factors potentially influencing dioxin sorption onto particles 
(such as temperature, humidity, and particle size, type and density), 
we believe our assumption that dioxins remain as vapors during their 
transport from the waste management unit source to the receptor 
location is appropriate. Because we understand that our assumption 
results in increased risk estimates, we are soliciting public comment 
on this issue. We also charged peer reviewers with providing comment on 
the issue during the peer review process, discussed in Section 
III.D.3., below.
2. What Are the Potential Risks to Ecological Receptors?
    EPA conducted an ecological risk screening analysis for the tank 
scenario for chlorinated aliphatics wastewaters, the land treatment 
unit and landfill waste management scenarios for EDC/VCM sludges, and 
for the landfill waste management scenario for methyl chloride sludges. 
The purpose of this analysis was to identify whether there is potential 
for adverse ecological effects resulting from the management of 
chlorinated aliphatics wastewaters, EDC/VCM sludges, and methyl 
chloride sludges. The screening analysis compares the modeled media 
concentrations to protective media concentrations in the form of a 
hazard quotient. When the hazard quotient exceeds 1, there is potential 
for adverse effects. If the hazard quotient is less than 1, we do not 
expect adverse effects for a particular ecological receptor. The amount 
by which the hazard quotient exceeds 1 suggests the potential for 
adverse ecological effects; however, the screening results do not 
demonstrate actual ecological effects, nor do they indicate whether 
those effects will have significant implications for ecosystems and 
their components.
    For the screening analysis, EPA applied a methodology designed to 
evaluate the potential for adverse ecological effects for selected 
receptors in generalized terrestrial and freshwater aquatic systems. 
The ecological risk screening analysis focused on a limited set of 
constituents of concern that were modeled for the human health risk 
analysis. For the selected ecological receptors, we developed 
protective contaminant concentrations in soil, sediment, and surface 
water that are based on conservative assumptions regarding exposure 
pathways and dietary preferences. The analysis included the following 
steps: (1) we developed chemical stressor concentration limits (CSCLs) 
\28\; (2) we compared the CSCLs to exposure point concentrations and 
calculated hazard quotients; and (3) we characterized key uncertainties 
and their impact on hazard quotients. We describe the results of this 
process in detail in the Risk Assessment Technical Background Document 
for the Chlorinated Aliphatics Listing Determination.
---------------------------------------------------------------------------

    \28\ Chemical stressor concentration limits are the containment 
concentrations in environmental media that are presumed to cause de 
minimis effects to ecological receptors.
---------------------------------------------------------------------------

    Based on the results of the analysis, we do not anticipate 
significant risk for the ecological receptors evaluated under either 
the high end or central tendency chlorinated aliphatic wastewater tank, 
EDC/VCM landfill, or methyl chloride landfill scenarios. However, there 
is indication of potential significant risk to ecological receptors 
under both the high end and central tendency EDC/VCM land treatment 
unit scenarios. These results support our conclusions for the human 
health risk analyses for EDC/VCM and methyl chloride sludges, that is, 
that there are risks posed by the management of EDC/VCM sludges in land 
treatment units, but not by the management of EDC/VCM sludges or methyl 
chloride sludges in landfills. Although we did not explicitly consider 
risks to threatened or endangered species, the CSCLs are protective 
media concentrations based on Agency-wide standards (e.g., Ambient 
Water Quality Criteria) and no observed adverse effects levels. The 
protective nature of the CSCLs implies some degree of protection for 
species already considered to be under stress. The ecological risk 
screening results are described in detail in the Risk Assessment 
Technical Background Document for the Chlorinated Aliphatics Listing 
Determination.
3. Did EPA Conduct a Peer Review of the Risk Assessment?
    The Agency has submitted the risk assessment to three independent 
experts for peer review. Their comments have been received and are in 
the docket for today's proposed rule. Due to the time constraints for 
proposal of this rule, the Agency has not yet reviewed and addressed 
those comments. Both the peer review comments and the public comments 
will be addressed in the final rulemaking.

E. Waste-Specific Listing Determination Rationales

    This section presents the rationale for today's proposed listing 
determinations for each of the identified categories of wastewaters and 
wastewater treatment sludges from the chlorinated aliphatic industry. 
EPA considered the listing criteria set out in 40 CFR 261.11, as 
incorporated into the risk assessments presented in Section III.D. 
above, as well as any other information relevant to the criteria, in 
making each of the listing determinations presented in this section. 
The criteria provided in 40 CFR 261.11 include eleven factors for 
determining ``substantial present or potential hazard to human health 
and the environment.'' As previously discussed at the beginning of 
Section III.D., nine of these factors relate to the risk assessments 
(constituent toxicity, concentration, waste quantity, migration 
potential, persistence, degradation

[[Page 46500]]

potential, bioaccumulation potential, plausible mismanagement, and 
other regulatory actions). Damage incidents (261.11(a)(3)(ix)) are 
investigated, and those that can be attributed to the wastes being 
evaluated are identified and considered in our evaluation.
    The following sections presents the rationale for each of the 
proposed listing determinations for wastes generated by the chlorinated 
aliphatics industry. Our rationale includes the results of our 
consideration of each of the factors listed above, the results of our 
risk assessment and other factors as may be appropriate.
1. Chlorinated Aliphatics Wastewaters
a. Wastewaters From the Production of Chlorinated Aliphatics
    As explained previously in Section III.A.1., the Agency segregated 
wastewaters from the chlorinated aliphatics industry into two waste 
groupings. Based upon current waste management practices, we grouped 
all chlorinated aliphatic wastewaters, except for those wastewaters 
generated from the production of vinyl chloride monomer using mercuric 
chloride catalyst in an acetylene-based process, into a single waste 
category for the listing determination investigation. We decided to 
study these wastewaters collectively because most chlorinated aliphatic 
manufacturers commingle wastewaters generated by individual processes 
prior to treating the wastewaters in a common wastewater treatment 
system. 29 In addition, many process wastewaters generated 
from the production of chlorinated aliphatic hydrocarbons contain 
similar constituents of concern.
---------------------------------------------------------------------------

    \29\ See Appendix D to Listing Background Document for the 
Chlorinated Aliphatic Listing Determination.
---------------------------------------------------------------------------

    EPA is proposing to list as hazardous process wastewaters generated 
from the production of chlorinated aliphatic hydrocarbons (other than 
those wastewaters generated from the production of vinyl chloride 
monomer using mercuric chloride catalyst in an acetylene-based process, 
discussed later in Section III.E.1.b of this preamble). The wastewaters 
meet the criteria set out at 40 CFR 261.11(a)(3) for listing a waste as 
hazardous and are capable of posing a substantial present or potential 
hazard to human health or the environment when mismanaged. As already 
described in the risk assessment results in Section III.D.1.f. of this 
preamble, we identified risks of concern associated with air releases 
of dioxins from wastewater treatment systems. The results of our risk 
analysis, which explicitly considers the factors listed in 40 CFR 
261.11(a)(3)(i)-(x), shows potential risks of concern for the farmer 
and child of farmer receptors, where the contaminants of concern are 
dioxins. The risk assessment results were presented previously in Table 
III-1 of Section III. D.1.f.
i. What Information Led EPA To Propose To List as Hazardous Process 
Wastewaters From the Production of Chlorinated Aliphatic Hydrocarbons?
    Responses to the 1996 RCRA Section 3007 chlorinated aliphatic 
industry survey indicated that approximately 11.5 million metric tons 
of chlorinated aliphatic wastewaters are generated annually. Survey 
responses and other publicly-available information also indicate that 
virtually all chlorinated aliphatic manufacturers treat these 
wastewaters in on-site, tank-based wastewater treatment systems prior 
to direct discharge of these wastewaters in accordance with facility-
specific NPDES permits. Other wastewater management practices 
identified include discharge off-site to either publicly-or privately-
owned treatment works (POTW, PrOTW), and storage and treatment in tanks 
prior to disposal in on-site underground injection wells. None of the 
facilities that responded to the questionnaire indicated that 
chlorinated aliphatic wastewaters currently are managed in surface 
impoundments.
    The Agency evaluated air pathway (vapor emissions) risks associated 
with the management of chlorinated aliphatics in wastewater treatment 
tanks. Our analysis of air emissions from the treatment of wastewaters 
was limited to an evaluation of air emissions from tank-based systems 
because the results of the RCRA Section 3007 survey showed that the 
chlorinated aliphatics industry manages wastewaters exclusively in 
tanks. Surface impoundments currently are not being used by this 
industry for the treatment of wastewaters, and based upon a review of 
industry trends, we anticipate that this industry will not use surface 
impoundments in the future. First, all of our data indicate that 
surface impoundments are no longer used by the chlorinated aliphatics 
manufacturers. In the 1992 RCRA 3007 survey responses, 5 facilities 
indicated they were using surface impoundments in the treatment of 
wastewater. In the 1997 RCRA 3007 survey update, only two facilities 
indicated they were using surface impoundments. We contacted the five 
facilities to confirm whether or not surface impoundments were being 
used, and learned that all of the impoundments had closed. Second, we 
do not believe it is likely that established tank-based wastewater 
treatment systems would be abandoned for surface impoundments-based 
systems, given that chlorinated aliphatic manufacturers have made the 
decision to convert to tank-based systems outside of regulations and 
after having considered other variables (e.g., liability concerns) and 
weighing all risks and benefits of tank-based systems. Further, 
impoundment-based systems are land intensive and land is valuable, 
particularly in industrial areas. Once a facility has reclaimed land 
previously used for surface impoundments, the facility is likely to 
then use that land for higher value operations. Therefore, we did not 
view surface impoundments as a plausible management for wastewaters 
within this industry.
    Given that wastewaters are managed in aerated biological treatment 
tanks, the emissions pathway of most concern is air emissions. Although 
such tanks often are open and may facilitate air releases, wastewater 
treatment tanks do restrict or eliminate the possibility of releases to 
groundwater via leaching. Tanks used to store and treat wastewaters 
generally are equipped with overflow and spill controls and are managed 
in compliance with structural integrity requirements that restrict the 
physical migration of wastes from the unit into the surrounding soil. 
However, given that a majority of the tanks used to treat chlorinated 
aliphatic wastewaters are designed to allow for aeration of the 
wastewater, these units may not completely control releases due to 
vapor emissions. Therefore, EPA determined that contaminant transport 
via air releases from tank-based systems was the most logical source of 
potential risk from managing these wastewaters.
    EPA collected 41 samples of chlorinated aliphatic wastewaters 
generated at 15 facilities. From the samples and analytical results we 
selected data for our risk analysis that represent wastewaters at the 
point where they are commingled prior to treatment. Since it is common 
for wastewaters to be combined prior to treatment in on-site wastewater 
treatment facilities, these commingled wastewaters are most 
representative of the wastewaters that actually are managed in tanks. 
Further, because the RCRA Section 3007 survey responses indicated that 
some facilities may commingle chlorinated aliphatic process wastewater 
with non-chlorinated aliphatic (e.g., petroleum refinery) process 
wastewater prior to treatment, we conducted our risk assessment using 
only waste characterization and volume data

[[Page 46501]]

representing ``dedicated'' wastewaters. We used data from these 
facilities to ensure that the results of our risk assessment would 
reflect only risks associated with the management of chlorinated 
aliphatic wastewaters.
    We also centered our analysis on an evaluation of chlorinated 
aliphatic wastewaters not currently defined as hazardous waste, and 
that are managed in aerated, uncovered biological treatment tanks. 
While not every facility currently uses biological treatment, this was 
the predominant practice observed during facility site visits and 
indicated in the RCRA Section 3007 survey. The risk analysis assumed 
that biological treatment occurs in aerated, uncovered tanks, because 
these conditions are typical for biological treatment in tanks and were 
confirmed to be occurring at some chlorinated aliphatic facilities 
treating non-hazardous, dedicated chlorinated aliphatic wastewaters. 
Also, because aeration increases air emissions, this scenario is 
expected to result in the highest risk estimates (compared with non-
aerated and/or covered tanks). Based upon survey response information 
and follow up inquiries with facility personnel, biological treatment 
in uncovered, aerated tanks was considered to be a plausible management 
scenario for wastewaters in the chlorinated aliphatics industry.
    The risks associated with vapor emissions of dioxin, as presented 
previously in Table III-1 in Section III.D.1.f., are significant for 
two receptors, the farmer and the farmer's child, and for one exposure 
route, the consumption of beef and dairy products. The high-end cancer 
risk for the farmer is 2E-05 and the central tendency risk is 4E-07. As 
explained previously, this risk is attributed to a local farmer's 
ingestion of dioxin due to his consumption of fruits, vegetables, beef 
and dairy products, all of which are grown or raised in an agricultural 
field located near a wastewater treatment unit used to treat 
chlorinated aliphatic wastewaters, as well as the farmer's incidental 
ingestion of soil from the agricultural field (see Section III.D.1.c). 
The high-end cancer risk for the farmer's child is 7E-06 and the 
central tendency risk is 3E-07. EPA also ran a Monte Carlo risk 
assessment on the air releases from these tanks. Probabilistic risk 
assessment results showed a risk of 1E-4 at the 95th percentile for the 
farmer, and for the child of farmer. This confirms the reasonableness 
of the deterministic analysis and the fact that regulation would be 
necessary to reduce the risk from the tank emissions to protect the 
farmers. At the 50th percentile, the probabilistic risk was 2E-7 for 
the farmer and the child of farmer.
    As described in Section III.D.1.f. of this preamble, the high-end 
parameters used in the risk assessment for dioxin emissions from 
wastewater treatment tanks were waste concentration and exposure 
duration. These results are based upon a concentration of dioxin in 
wastewaters associated with the highest concentration of dioxin we 
found for the wastewater samples used in the analysis. Further 
discussion of the assumptions and parameters used in the risk 
assessment is provided in Section III.D. of this preamble and in the 
Risk Assessment Technical Background Document for the Chlorinated 
Aliphatics Listing Determination that is in the docket for today's 
proposed rule.
    Our analyses also showed marginal risks of concern for the farmer, 
child of farmer, home gardener, adult and child resident, and fisher, 
from direct inhalation of chloroform. The high-end cancer risk for the 
farmer from direct inhalation of chloroform is 3E-06. In addition, the 
high end cancer risk to the child of farmer, child resident, adult 
resident, home gardener, and the fisher from direct inhalation of 
chloroform is 2E-06. The central tendency risk from chloroform 
inhalation for the farmer, child of farmer, child resident, home 
gardener, fisher and adult resident is 8E-08.
    EPA is confident that the constituents of most concern, dioxins and 
chloroform, were identified. In addition, we are confident that the 
assumptions and parameter values used in our risk modeling reflect 
``high-end'' or ``reasonable worse case'' circumstances. Risks are 
unlikely to be significantly higher than shown by our modeling results. 
In Section III.D.1.h. of today's preamble, we describe in more detail 
sources of potential uncertainty in the risk results that may result in 
under- or over-estimations of risk.
    Based on an analysis of the risks associated with current 
management practices, EPA is proposing to list wastewaters from the 
production of chlorinated aliphatic hydrocarbons as hazardous waste 
(EPA Hazardous Waste Number K173.) EPA's proposal to list this waste is 
consistent with the guidance the Agency has used for determining that a 
waste is hazardous (see 59 FR 66077), i.e., the risks associated with 
management of wastewaters in aerated biological treatment tanks due to 
vapor emissions of dioxins are above the 1E-5 listing benchmark. This 
guidance also provides that EPA can consider additional factors in 
cases where risk assessment results indicate a risk level of between 
1E-4 and 1E-6, as is the case here. These additional factors include: 
certainty of waste characterization; certainty in risk assessment 
methodology; coverage by other regulatory programs; waste volume; 
evidence of co-occurrence of hazardous constituents; damage cases 
showing actual impact to human health or the environment; and presence 
of toxicants of unknown or unquantifiable risk.
    With regard to certainty of waste characterization, as explained in 
Section III.D., the Agency collected and analyzed 41 samples of 
wastewaters generated from the production of chlorinated aliphatic 
chemicals, six of which were collected at the influent (``headworks'') 
of the wastewater treatment system. Given that we used these six 
``dedicated'' samples in our risk assessment, we are certain that our 
analysis evaluated without question the risks attributable to the 
wastewaters of concern.
    With respect to certainty in risk assessment methodology, we note 
that there is discussion of uncertainty in the risk assessment 
methodology in section III.D.1.h. of today's preamble. As mentioned in 
that section, we selected the models we used because we generally 
consider them to be state-of-the-science, and because they are used 
widely and have been accepted for numerous applications. However, as 
mentioned, they each retain significant sources of uncertainty that as 
a whole could result in either an overestimation or underestimation of 
risk. Should the Agency determine, based upon public comment or as a 
result of the peer review of the risk assessment methodology, that the 
wastewater risk assessment has overestimated the risks such that a 
decision to list this residual is not warranted, the Agency may 
ultimately decide against listing this waste.
    We considered coverage by other regulatory programs in making our 
proposed listing determination for chlorinated aliphatic wastewaters. 
In fact, as discussed further below, our decision to propose to list 
these wastewaters and to propose technical standards to address air 
emissions from treatment tanks managing these wastewaters, is directly 
related to the fact that current regulatory programs do not appear to 
adequately address the type of air releases from these units that 
showed risk in our analysis.
    Waste volume is part of our risk level calculations. As explained 
in section III.D., risk is projected based on the volume of waste 
managed under each modeled waste management scenario.

[[Page 46502]]

We note that there is a significant volume of chlorinated aliphatic 
wastewater generated annually (11.5 million metric tons). Our risk 
assessment methodology also accounts for the co-occurrence of hazardous 
constituents in any particular waste. Section III.D.1.b. discusses the 
number of potential constituents of potential concern identified in 
each wastestream. A more detailed discussion of the constituents of 
potential concern detected in each wastestream analyzed is provided in 
the Risk Assessment Technical Background Document for the Chlorinated 
Aliphatics Listing Determination for this rule, which is available in 
the docket for today's rule.
    With regard to the remaining factor in Sec. 261.11(a)(3), no actual 
damage incidents have been observed (Sec. 261.11(a)(3)(ix)). However, 
the risk levels indicated, large waste volumes, certainty of waste 
characterization and risk assessment, coverage by other regulatory 
programs, and accounting for co-occurrence of constituents in the 
waste, outweigh the lack of observed damages. This is because the 
potential risks associated with this wastestream would be long term. 
Such risks are very difficult to directly attribute to any particular 
cause and can result even in the absence of observable releases. Our 
failure to observe damages incidents does not mean they have not 
occurred or that risks are not being imposed upon surrounding 
populations. RCRA is designed to be a prospectively-protective statute 
and the Agency need not wait for actual damages to be observed.
    As discussed previously, the risk assessment addresses nine of the 
listing criteria in 40 CFR 261.11. EPA believes the risks resulting 
from our analysis represent plausible management of these wastes 
(Sec. 261.11(a)(3)(vii)) using reasonable assumptions for treatment of 
wastewaters in tanks. In addition, the risk analysis was developed 
using actual analytical data. However, the Agency still recognizes that 
sources of uncertainty could be contributing to an overestimation of 
risk. The Agency points out that risk modeling results show risks at 
significant levels only in cases where sensitive input parameters are 
assumed to represent high-end circumstances.
    Finally, the Agency did not model wastewaters that are already 
defined as hazardous wastes (i.e., wastes mixed with or derived-from 
other existing listed wastes, or exhibiting a characteristic of 
hazardous waste), because we assume these wastes are already, and will 
continue to be, properly handled as hazardous. On-site injection of 
wastewaters to a permitted UIC well also was not modeled. Although 
information obtained from the RCRA Section 3007 questionnaire and other 
publicly available information indicate that some chlorinated aliphatic 
manufacturing facilities manage wastewaters via underground injection, 
the majority of these wastewaters currently are managed as hazardous 
wastes and injected into Class I permitted hazardous waste UIC wells in 
accordance with approved no-migration petitions. Only one facility 
manages chlorinated aliphatic wastewaters as non-hazardous waste and 
injects the wastewaters in a permitted UIC well.
    Although we have proposed to list this wastestream, we recognize 
that our estimates of the risks associated with this wastestream are 
within the range in which the Agency has stated it may consider other 
factors in deciding whether to list a waste. EPA invites comment as to 
whether there are other factors EPA should consider that would further 
support a final decision to list this waste or that would support a 
conclusion that EPA should not list this waste. EPA has, for example, 
asked for comment earlier in section D.1.f.ii. regarding whether to 
consider population risk.
ii. What is the Scope of Today's Proposed Listing Determination for 
Chlorinated Aliphatic Wastewaters?
    The scope of today's proposed listing includes all wastewaters 
generated by chlorinated aliphatic production processes, except for 
wastewaters generated from the production of vinyl chloride monomer 
using mercuric chloride catalyst in an acetylene-based process (VCM-A 
process). These wastewaters were evaluated separately (see section 
III.E.1.b.). The listing description for chlorinated aliphatic 
wastewaters is as follows:

K173  Wastewaters from the production of chlorinated aliphatic 
hydrocarbons, except wastewaters generated from the production of 
vinyl chloride monomer using mercuric chloride catalyst in an 
acetylene-based process. This listing includes wastewaters from the 
production of chlorinated aliphatic hydrocarbons having carbon chain 
lengths ranging from one to and including five, with varying amounts 
and positions of chlorine substitution.
iii. What Is the Proposed Regulatory Status of Sludges Derived From the 
Treatment of Wastewaters Covered by the Proposed Listing Determination?
    The Agency is proposing to amend the current RCRA regulations so 
that wastewater treatment sludges generated from the treatment of 
wastewaters proposed to be listed as hazardous waste K173 will not be 
classified as hazardous waste as a result of the ``derived-from'' rule 
(40 CFR 261.3(c)(2)(i)). The proposed amendment to the derived from 
rule will exempt sludges derived from the processing or management of 
proposed K173, as long as the wastes would not otherwise be defined as 
hazardous waste, absent the proposed K173 listing. As presented 
elsewhere in today's proposed rule, EPA has studied wastewater 
treatment sludges from the chlorinated aliphatics industry and made 
independent hazardous waste listing determinations for several 
categories of sludges. These independent evaluations of the potential 
risks associated with wastewater treatment sludges derived from today's 
proposed K173 wastewaters supercede any presumed risk imparted by 
application of the derived-from rule in this instance. These risk 
evaluations logically should take precedent over the application of the 
derived-from rule, which presumes risk absent any information on 
toxicity of the treatment residual. The Agency points out, however, 
that sludges and other residuals generated as a result of managing 
chlorinated aliphatic wastewaters that carry waste codes other than 
K173, and residuals that otherwise are listed hazardous wastes (or 
exhibit a characteristic of hazardous waste) remain hazardous wastes.
    EPA is today proposing to add a new paragraph (E) to the derived-
from regulations at 40 CFR 261.3(c)(2)(ii) to make clear that 
wastewater treatment sludges derived-from treating K173 wastewaters 
will not be hazardous waste via the derived-from rule.
iv. What Comments Is EPA Specifically Requesting on the Proposed 
Listing of Chlorinated Aliphatic Wastewaters?
    The Agency requests comments on the proposed listing of wastewaters 
from the production of chlorinated aliphatic hydrocarbons, 
specifically, how would specific areas of potential uncertainty justify 
a decision to list or not list these wastewaters as hazardous.
v. How Does the Agency Propose To Address the Risks Associated With 
Chlorinated Aliphatic Wastewaters Affected by the Proposed Listing?
    Owners and operators of wastewater treatment units, as defined in 
40 CFR 260.10, are not required to obtain a RCRA permit or comply with 
the management standards of 40 CFR Parts 264 (permitted facilities) and 
265 (interim status facilities) when managing hazardous wastes in such

[[Page 46503]]

units (40 CFR 264.1(g)(6) and 265.1(c)(10)). Section 260.10 defines a 
wastewater treatment unit as a device which (1) is a part of a 
wastewater treatment facility that is subject to regulation under 
Sec. 402 or Sec. 307(b) of the Clean Water Act; (2) receives and treats 
or stores an influent wastewater that is a hazardous waste, generates 
and accumulates a wastewater treatment sludge that is a hazardous 
waste, or treats or stores a wastewater treatment sludge that is a 
hazardous waste; and (3) meets the definition of a tank or tank system.
    The results of the Agency's risk assessment for chlorinated 
aliphatic wastewaters shows significant risks due to air emissions of 
dioxins from uncovered and aerated biological treatment tanks. The 
Agency's proposed listing determination for these wastewaters alone 
will not address the risk pathway of concern, due to the regulatory 
exemption for wastewater treatment units. To address the risks 
associated with the management of proposed K173 chlorinated aliphatic 
wastewaters, the Agency is proposing to require that wastewater 
treatment units used to treat chlorinated aliphatic wastewaters comply 
with specific requirements in 40 CFR Parts 264 and 265, subpart CC (Air 
Emission Standards for Tanks, Surface Impoundments, and Containers). 
The Agency's objective is to require air emission controls for 
wastewater treatment tanks managing these wastewaters to prevent the 
release of dioxin vapor emissions to the environment. These proposed 
requirements would be enforceable requirements of RCRA subtitle C.
    By this limited proposal to change the exemption for wastewater 
treatment tanks that are used to treat chlorinated aliphatic 
wastewaters, which is based only on a risk assessment of certain kinds 
of tanks used to treat these specific wastewaters, EPA is not reopening 
any other aspect of the wastewater treatment unit exemption.

What Type of Requirements is EPA Proposing To Prevent Air Releases From 
These Tanks?

    EPA considered simply requiring that the tanks be ``covered'' to 
prevent air releases of dioxins from K173 wastewaters. However, it 
became apparent that such a simplified approach might not provide 
adequate guidance to the regulated community on how to ensure they are 
complying with this type of performance standard. The Agency determined 
that the existing requirements for controlling air emissions from 
hazardous waste tanks, in subpart CC of 40 CFR Parts 264 and 265, could 
be used with some modifications to meet the goal of controlling air 
emissions from tanks managing proposed K173 wastewaters.
    Currently, the 40 CFR 264/265 subpart CC requirements address 
volatile organic (VO) emissions from hazardous waste managed in tanks, 
surface impoundments, and containers. Therefore, many of the provisions 
in subpart CC (e.g., the VO concentration threshold of 500 parts per 
million by weight for determining applicability of the Subpart CC 
requirements) are not appropriate for dioxin emissions. However, other 
provisions (namely, the technical standards for covering tanks and 
controlling emissions in Sections 264.1084 and 265.1085) are 
appropriate for controlling air emissions from wastewater treatment 
tanks managing K173 wastewaters. Therefore, EPA is proposing to amend 
the subpart CC requirements (described in more detail below) so that 
specific technical standards already in subpart CC for tank emissions 
apply to tanks managing K173 wastewaters. (The Agency notes that the 
standards being proposed today, if finalized, will apply irrespective 
of the VOC content of the wastewater.) We also recognize that dioxin 
levels vary among generators, and thus are proposing a trigger level 
for dioxins below which compliance with subpart CC is not required. 
This is because our analytical data indicate that there is a range of 
dioxin levels in the chlorinated aliphatic wastewaters.30 In 
particular, two samples contained TCDD TEQ levels that were four orders 
of magnitude lower than both the maximum and average TCDD TEQ 
concentrations.
---------------------------------------------------------------------------

    \30\ See Appendix B of ``Listing Background Document for the 
Chlorinated Aliphatics Listing Determination.''
---------------------------------------------------------------------------

How Did EPA Develop the 2,3,7,8-TCDD TEQ Limit for Wastewaters?

    EPA's first step in establishing a concentration limit for dioxins 
was to determine whether we should set the limit as a 2,3,7,8-TCDD TEQ 
(TCDD TEQ) concentration, or as a set of individual limits for each of 
the specific dioxin congeners. We decided to set the limit as a 2,3,7,8 
TCDD TEQ concentration. In making this decision, we considered the 
analytical results from the six dedicated chlorinated aliphatics 
headworks wastewater samples collected during the record sampling 
effort (see Section III.D.1.b.). We determined that wastewaters from 
the production of chlorinated aliphatic chemicals do not carry a 
distinct congener ``fingerprint,'' that is, certain congeners are not 
consistently more prevalent in samples of chlorinated aliphatics 
wastewaters than other congeners. Because the congener composition of 
chlorinated aliphatic wastewaters is not consistent or distinct, 
setting limits on a congener-specific basis likely would be overly-
restrictive for some facilities. Specifically, the limit set for a 
given congener would need to be protective in cases where a number of 
different congeners contribute to the wastewater's dioxin toxicity or 
risk (thereby requiring that lower limits be set for each congener to 
ensure that the combined emissions of each congener would not generate 
unacceptable risk). Such limits might be overly restrictive for those 
wastewaters with a dioxin composition that is dominated by a much 
smaller number of congeners. Moreover, setting the dioxin limit as a 
TCDD TEQ is consistent with the approach we have taken with other 
regulations, such as the Water Quality Guidance for the Great Lakes 
System, 40 CFR Part 132, Appendix F.
    After considering options for setting the TCDD TEQ limit, we chose 
to base the TCDD TEQ limit on the lowest TCDD TEQ concentration 
measured in a dedicated wastewater sample for which a high end 
deterministic risk estimate is 1  x  10-5. This 
concentration is 0.6 ng/L, calculated using the TEFs developed by the 
World Health Organization, and corresponding to the TCDD TEQ 
concentration for EPA's sample no. PL-02. (The TCDD TEQ concentration 
based on the I-TEFs is 0.7 ng/L. See section III.D.1.g.ii. for an 
explanation of the TEFs). The high end deterministic risk estimate was 
based on the evaluation of a farmer scenario (see section III.D.1.f.) 
in which the exposure duration of the farmer was set at its high end 
value, 48.3 years. For the purpose of establishing the TCDD TEQ limit, 
we did not set any additional values at high end. We used the ``single 
high end'' approach to account for sources of uncertainty in the risk 
analysis and our understanding that not all of the underlying 
assumptions of the analysis may be relevant to any one chlorinated 
aliphatics facility. For example, not all facilities may operate the 
type of aerated biological treatment tank that was modeled, grazing of 
cattle may not occur in the vicinity of all facilities on the 
centerline of the contaminant plume (the farmer's risk primarily is due 
to the ingestion of contaminated beef and dairy products). For 
reference, the adult resident's ``single high end'' risk is 1  x  
10-9 when the wastewater concentration

[[Page 46504]]

is 0.6 ng/L (based on meteorological location as a high end parameter).
    The 1  x  10-5 risk result for the farmer is based on 
predicted long-term average exposures assuming a wastewater TCDD TEQ 
concentration of 0.6 ng/L, as well as certain other environmental and 
exposure factors. This means that over the long term, the receptor is 
protected at the 1  x  10-5 level when, on average, the TCDD 
TEQ concentration in the wastewater is 0.6 ng/L. That is, it is 
implicit in the analysis that even if there are excursions of the 
wastewater TCDD TEQ concentration above 0.6 ng/L, an individual is 
still protected at the 1  x  10-5 risk level if on average 
the wastewater TCDD TEQ concentration is 0.6 ng/L. Today EPA is 
proposing to set the TCDD TEQ limit for wastewaters at 1 ng/L. Setting 
the limit at 1 ng/L accounts for the fact that we believe facilities 
who comply with the requirement that the TCDD TEQ concentrations of 
their wastewaters not exceed 1 ng/L will on average maintain wastewater 
TCDD TEQ concentrations of approximately 0.6 ng/L or below. EPA is 
proposing that wastewater treatment tanks managing proposed K173 
wastewaters, where the TCDD TEQ concentration in the wastewater is 
greater than or equal to 1 ng/L, comply with specific air emission 
control regulations, as described in more detail below.
    It is important to note that the 1 ng/L trigger level described 
here for implementing the proposed tank cover requirement is not a 
concentration below which the wastewater does not meet the K173 
listing. This proposed listing follows what can be described as the 
traditional approach EPA has taken for hazardous waste listings (i.e., 
if a particular facility's waste meets the listing description, it is 
listed regardless of the concentration of constituents or waste 
management practice employed). While we are proposing to list 
wastewaters following this traditional approach, today's rule does 
establish a concentration level for wastewaters that reflect the 
Agency's concern for dioxin managed in tanks within this industry. We 
seek comment on the alternative of using this level as criteria for the 
listing itself. The Agency could finalize a concentration based listing 
based on the 1 ng/L trigger level instead of the traditional listing 
proposed today. The Agency also seeks comment on whether this 
concentration-based listing approach should be implemented in the same 
manner as is described in this notice (i.e., where the 1 ng/L 
concentration is a trigger for requiring tank covers), or 
alternatively, whether it would be more appropriate to apply the 
implementation approaches described in the July 23, 1999 rulemaking for 
the dyes and pigments industry (placed in the docket for today's 
rulemaking for convenience).

How Will These Air Emission Controls Be Implemented?

    As described below, we are proposing that generators of K173 who 
manage these wastes in tanks comply with certain air emission control 
requirements, including covering their tanks, unless the results of 
testing the wastewater influent to the tank indicate that the dioxin 
concentrations are below the 1 ng/L trigger level. Our proposed 
approach consists of the following elements:

     Each wastewater treatment tank managing K173 that is 
not compliant with 40 CFR sections 264.1084/265.1085 of subpart CC 
must be assessed to determine whether dioxin levels in the influent 
to the tank exceed the trigger level.
     For the purposes of this listing, the headworks of the 
wastewater treatment system is assumed to be at a location directly 
after steam stripping. If a facility does not utilize steam 
stripping, the wastewater treatment system headworks is assumed to 
be the first tank in which wastewaters are combined, accumulated or 
treated after leaving the chlorinated aliphatics production process.
     Tanks that are fully compliant with sections 264.1084/
265.1085 of 40 CFR subpart CC would not be subject to waste 
analysis, record keeping and notification requirements proposed in 
today's rule to be added to 40 CFR 265.1080(f)(1)-(5), described 
below.
     Once the facility has established that TCDD TEQ levels 
do not exceed the trigger level for a specific tank, the facility 
can assume that the TCDD TEQ levels for all downstream tanks also 
are below the trigger level.
     The facility must develop a waste analysis plan prior 
to sampling and analysis to ensure that the measurements are 
sufficiently sensitive, accurate and precise to demonstrate 
compliance, as described further below. We suggest that the waste 
analysis plan be developed in accordance with Agency 
guidance.31
---------------------------------------------------------------------------

    \31\ Chapter Nine of ``Test Methods for Evaluating Solid Waste, 
Physical/Chemical Methods'' (SW-846) addresses the development and 
implementation of a scientifically credible sampling plan. Chapter 
One of SW-846 describes the basic elements to be included in a 
Quality Assurance Project Plan (QAPP), as well as information 
describing basic quality assurance (QA) and quality control (QC) 
procedures. Chapter Two of SW-846 aids the analyst in choosing the 
appropriate methods for samples, based upon sample matrix and the 
analytes to be determined. Other appropriate sources may also be 
used, including those issued by recognized national voluntary 
standards setting organizations, e.g., ASTM, etc., http://
www.epa.gov/ncepihom/Catalog/EPASW-846.3.4A.html
---------------------------------------------------------------------------

     The initial assessment must be conducted by the 
effective date of the rule. If the trigger level is exceeded, 
compliance with the applicable sections of 40 CFR 264/265 subpart CC 
must be accomplished within one year of the effective date. 
Alternatively, the facility may implement process changes to reduce 
the TCDD TEQ level below the trigger level, and repeat the initial 
assessment to demonstrate that levels are now below the trigger 
level, within the same one year time frame.
     If it is determined that the TCDD TEQ concentration 
measured during the initial assessment is below the trigger level, 
re-assessment would be required (1) as a result of any process 
changes that would impact dioxin wastewater levels, and (2) 
annually.
     If the trigger level is not exceeded, the facility must 
submit a one-time notification and certification.
     The facility must maintain records on site.

Sampling and Analysis

    In designing the sampling program, the facility must consider any 
expected fluctuations in concentrations over time. The sample design 
should be described in the waste analysis plan, which must be retained 
in the facility's files. The sample design must be adequate to 
determine that the level of TCDD TEQ in the wastewater is above or 
below the 1 ng/L at a 95 percent upper confidence limit around the 
mean. This approach is being used in the comparable fuels final rule 
(June 19, 1998; 63 FR 33782). See also Guidance for Data Quality 
Assessment--Practical Methods for Data Analysis, EPA QA/G-9, January 
1998, EPA/600/R-96/084. Under this approach, EPA is not specifying a 
specific number of samples, because the number of samples required to 
demonstrate that the wastewater dioxin concentration is below 1 ng/L at 
the 95 percent upper confidence limit depends on how close the actual 
concentration is to the regulatory limit and on the variability of the 
waste. EPA is proposing that the samples used to demonstrate compliance 
be grab samples collected within a time period that will accurately 
account for potential variability in the wastestream, including 
potential variabilities associated with batch and continuous processes. 
If properly stored, the holding time for unprocessed aqueous samples of 
dioxins/furans (which can be found in the Sample Collection, Handling 
and Preservation section of Method 8290) allows for multiple samples to 
be collected and be available should additional analysis be required to 
achieve the data quality objective of determining compliance with the 1 
ng/L limit at a 95% upper confidence limit around the mean.
    EPA also is proposing an alternative sample design criteria. The 
alternative approach is to set a maximum

[[Page 46505]]

quantitation value as an alternative to the use of the 95% upper 
confidence limit around the mean. Under this approach, the Agency is 
proposing that the analytical quantitation limits should be sufficient 
to calculate a meaningful TCDD TEQ for comparison to the 1 
ng/L trigger level. Our experience with this matrix is that 
quantitation at or below 0.05 ng/L should be routinely achievable, 
therefore we are proposing that the selected analytical method achieve 
a precision of at least 30 percent relative standard deviation at a 
calibration level of 0.05 ng/L and a recovery of greater than or equal 
to 70 percent 32 (we note that if isotope-dilution methods 
are used, recovery is not an issue, since this method is self-
correcting for recovery.) Under this approach, EPA is specifying that a 
minimum of four grab samples be collected within a 24-hour time period. 
The Agency notes that although we are considering setting a lower 
calibration standard for the measurement method as an alternative to 
the 95 percent upper confidence limit around the mean standard, the 
regulatory language included with today's proposal reflects only the 
preferred option.
---------------------------------------------------------------------------

    \32\ Recent recovery is from an EPA Memorandum from Barnes 
Johnson, Director of the Economics, Methods, and Risk Assessment 
Division, to James Berlow, Director of the Hazardous Waste 
Minimization and Management Division, regarding the Office of Solid 
Waste's (OSW) standing policy on the Appropriate Selection and 
Performance of Analytical Methods for Waste Matrices Considered to 
be ``Difficult-to-Analyze,'' January 31, 1996.
---------------------------------------------------------------------------

    Generators may not use process knowledge to determine whether or 
not the 1 ng/L TCDD TEQ trigger level has been exceeded for the first 
tanks in the wastewater treatment system where constituent 
concentrations are likely to be highest. However, once the facility has 
established that the trigger level is not exceeded in the influent to a 
given tank, the facility may use process knowledge to determine that 
dioxin levels in wastewaters managed in subsequent downstream tanks 
also will not exceed the trigger level.
    We are proposing that the generator maintain documentation of the: 
(1) detailed standard operating procedures (SOPs) for the sampling and 
analysis protocols that were employed; (2) sensitivity and bias of the 
measurement process; (3) precision of the analytical results for each 
batch of waste tested; and (4) analytical results.
    It is the responsibility of the generator to ensure that the 
sampling and analysis is unbiased, precise, and representative of the 
tank influent. To show that a tank is not subject to the specific 
Subpart CC requirements applicable to K173 wastewaters, a generator 
must demonstrate that: (1) the maximum TCDD TEQ in the tank influent 
does not exceed the 1 ng/L trigger level; and (2) the analysis could 
have detected the presence of the CDD/CDF congeners at or below the 
trigger level.
    We are not requiring the use of SW-846 methods to comply with these 
requirements. We are proposing to allow the use of alternative methods 
to those included in SW-846, so long as the selected methods meet the 
following performance based criteria.
    The Agency will consider the analysis adequate to demonstrate that 
the trigger level of 1 ng/L is not exceeded if an analysis in which 
TCDD (as a surrogate for all of the CDD/CDF congeners) spiked at the 
trigger level indicates that the analyte is present at that level 
within analytical method performance limits (e.g., sensitivity, bias 
and precision). To determine the performance limits for a method, EPA 
recommends following the quality control (QC) guidance provided in 
Chapters One and Two of SW-846, and the additional QC guidance provided 
in Method 8290.
vi. What Comments Is EPA Specifically Requesting on the Proposed 
Approach for Controlling Dioxin Air Emissions?
    The Agency requests comment on the proposal to add air emission 
control requirements for tanks used to manage chlorinated aliphatic 
wastewaters. In addition, the Agency requests comment on whether the 
technical standards in 264.1084/265.1085 will address the risks 
associated with vapor emissions from these units. EPA requests comment 
on the proposed 1 ng/L TCDD TEQ concentration limit in wastewater that 
triggers application of the air emission control requirements, and on 
the testing and recordkeeping requirements for implementing this 
standard. Specifically, EPA is requesting comment on comparing the 
regulatory limit to a sample mean at the 95% upper confidence limit, 
versus a maximum sample value with the sensitivity (as demonstrated by 
the lower calibration standard), precision, and recovery (unless using 
the isotope-dilution method) described in today's proposal.
    In addition, we request comment on whether or not there are other 
types of standards and/or other factors the Agency should consider in 
setting standards for wastewater treatment units used to manage 
chlorinated aliphatic wastewaters. The Agency is not reconsidering or 
requesting comment on the wastewater treatment unit exemption and does 
not intend to respond to any comments submitted regarding the 
exemption.
b. How Is EPA Proposing to Regulate VCM-A Wastewaters?
    EPA is proposing not to list as hazardous wastewaters generated 
from the production of VCM using mercuric chloride catalyst in an 
acetylene-based process. This wastestream already is defined as 
hazardous waste due to the fact that it exhibits the toxicity 
characteristic.
i. What Information Led EPA To Propose Not to List as Hazardous 
Wastewaters From the VCM-A Process?
    EPA knows of only one facility in the United States that operates 
an acetylene-based VCM production process, which uses mercuric chloride 
catalysts in the production of VCM. The management of spent mercuric 
chloride catalyst used in the VCM-A production process results in the 
generation of a wastewater containing mercuric chloride, as well as 
vinyl chloride. The wastewater treatment system is operated in a batch 
process fashion in tanks, and is designed to convert the mercuric 
chloride present in the process wastewaters to an much less soluble 
mercuric sulfide. The mercuric sulfide is precipitated during the 
treatment process, dewatered, and collected for off-site disposal. The 
remaining wastewaters are discharged directly under an NPDES permit. 
Due to the fact that this wastewater is managed in a single, dedicated 
wastewater treatment system associated with a unique production 
process, and the presence of mercury in relatively high concentrations 
(which is not found in other chlorinated aliphatic wastewaters), the 
Agency decided to consider this wastestream separately in our 
investigation of the wastes generated by the chlorinated aliphatic 
hydrocarbons manufacturing industry.
    According to the RCRA Section 3007 survey response, the facility 
generates and discharges approximately 22,200 metric tons (5.86 million 
gallons) of wastewater from the VCM-A process each year. The identified 
constituents of concern in this wastestream include mercury and vinyl 
chloride. In addition, dioxins are present in these wastewaters. EPA 
analyzed one sample of this wastewater in 1996 in support of this 
listing determination. The analytical results showed the wastewaters 
contained 8.60 mg/L mercury, and 0.680 mg/L vinyl chloride. The 
analytical results for the split sample taken by the facility were 6.78 
mg/L mercury, and 1.38 mg/L vinyl chloride. The results exceed the 
toxicity

[[Page 46506]]

characteristic regulatory levels of 0.2 mg/L for mercury and 0.2 mg/L 
for vinyl chloride. Dioxins also were detected in the VCM-A 
wastewaters, however, the concentration was several orders of magnitude 
lower than levels found in other wastewaters generated from other 
chlorinated aliphatic manufacturing processes (i.e., 0.0022 ng/L TEQ/
TCDD).
    Based upon EPA's one record sample, this wastestream already is 
identified as a hazardous waste due to the fact that the waste exhibits 
the toxicity characteristic (TC). The constituents of significant 
concern in the VCM-A wastewaters (i.e., mercury and vinyl chloride) 
already are regulated under the TC, therefore, the TC adequately 
defines this wastestream as hazardous. Further, the facility's 
dedicated wastewater treatment system was designed and optimized 
expressly for the removal of mercury from mercuric chloride catalysts 
to comply with the Clean Water Act. In addition, given the fact that 
EPA's record sample was over 40 times above the TC limit for mercury, 
it is highly probable that these wasetwaters routinely contain levels 
of mercury which cause this wastestream to be defined as 
characteristically hazardous waste. As mentioned previously, the 
criteria in 40 CFR 261.11 (a)(3) for evaluating whether or not a solid 
waste is a hazardous waste provide that EPA should consider how the 
waste (and potential risk) is affected by other regulatory programs 
(i.e., 261.11(a)(3)(x)). In the case of the VCM-A wastewaters, EPA 
notes that our decision to propose not to list this wastewater as 
hazardous is based in large part on the fact that the waste already is 
defined as a hazardous waste because it exhibits the toxicity 
characteristic. We have, accordingly, determined that there is no 
regulatory benefit in listing this wastewater as hazardous, 
particularly when considering that the volume of wastewater generated 
by the single facility using the acetylene-based VCM production process 
is relatively small (22,200 metric tons annually) compared to the 
volumes of wastewaters generated in other chlorinated aliphatic 
wastewater treatment systems (11.5 million metric tons annually).
    In addition, any risks associated with the management and disposal 
(i.e., direct discharge) of the wastewaters are addressed by other 
environmental regulations. With respect to the discharge of the 
wastewater, the facility treats and discharges the wastewater in 
compliance with the conditions of a NPDES permit. Regarding any air 
emissions of vinyl chloride from these wastewaters, vinyl chloride is a 
hazardous air pollutant, therefore the facility is subject to the 
National Emissions Standards for Hazardous Air Pollutants (NESHAP) 
requirements specific to vinyl chloride emissions (40 CFR Section 
61.65), as well as the Hazardous Organic NESHAP for the synthetic and 
organic chemical manufacturing industry sector (40 CFR Part 63, subpart 
G) (59 FR 19468, April 22, 1994). For these reasons, the Agency is 
proposing not to list VCM-A wastewaters as hazardous waste.
    Sludges generated by the wastewater treatment process are disposed 
of in an off-site hazardous waste (subtitle C) landfill. EPA conducted 
a separate investigation of these sludges. The results of this 
investigation and our listing determination for the VCM-A wastewater 
treatment sludges are summarized in section III.E.3. further below.
2. EDC/VCM Wastewater Treatment Sludges
a. How Is EPA Proposing To Regulate EDC/VCM Wastewater Treatment 
Sludges?
    EPA is proposing to list as hazardous sludges generated from 
treating wastewaters associated with the manufacture of ethylene 
dichloride (EDC) and vinyl chloride monomer (VCM). This wastestream 
meets the criteria set out at 40 CFR 261.11(a)(3) for listing a waste 
as hazardous and is capable of posing a substantial present or 
potential hazard to human health or the environment when managed in 
land treatment units. The Agency identified risks of concern associated 
with one management practice, on-site land treatment. In our risk 
assessment of these wastes, the exposed individuals of concern were the 
farmer, child of farmer, and the fisher receptors. The contaminants of 
concern are dioxin and arsenic.
    As discussed in section III.D.1 above, our analyses identified 
health risks from the land treatment of the EDC/VCM wastewater 
treatment sludges due to airborne releases and subsequent deposition 
and food chain contamination from dioxin. Surface erosion due to runoff 
also contributes to risk from dioxin. Marginal risks from arsenic were 
identified for the land treatment unit groundwater ingestion exposure 
pathway. We also modeled a landfill management scenario; our risk 
assessment showed no significant risk from dioxin, and only marginal 
risk from arsenic associated with the groundwater pathway.
b. What Information Led EPA To Propose To List as Hazardous EDC/VCM 
Wastewater Treatment Sludges?
    The results of the RCRA Section 3007 chlorinated aliphatic industry 
survey show that approximately 104,606 metric tons of wastewater 
treatment sludge is generated from the treatment of wastewaters at 
chlorinated aliphatic plants that manufacture VCM and/or EDC. One 
facility accounts for 74 percent of the total volume of wastewater 
treatment sludge generated.33 Of the total volume of 
wastewater treatment sludges generated at plants manufacturing EDC/VCM 
and identified through the survey, 6,757 metric tons (6 percent) 
currently are already defined as hazardous waste.
---------------------------------------------------------------------------

    \33\ Only one (1) percent of the wastewaters at this facility 
are generated from the manufacturing of EDC/VCM.
---------------------------------------------------------------------------

    EDC/VCM wastewater treatment sludges are generated at 12 
facilities. The Agency notes that these sludges are not always 
generated from treating wastewaters produced exclusively from EDC and/
or VCM manufacturing processes. Rather, sludges are sometimes generated 
in wastewater treatment systems that treat wastewaters from 
manufacturing processes producing a variety of chlorinated aliphatic 
and non-chlorinated aliphatic products. Wastewaters from multiple 
processes are combined prior to wastewater treatment. The Agency points 
out that the listing determination proposed today for EDC/VCM 
wastewater treatment sludges affects the total quantity of the sludges 
generated by a wastewater treatment system that accepts influent from 
any process manufacturing EDC and/or VCM. EPA has made this clear by 
including sludges from commingled EDC/VCM wastewater and other 
wastewater within the scope of the listing, although EPA believes this 
would have been the correct interpretation of the listing even absent 
the clarifying language.
    The management scenarios selected for risk assessment were chosen 
based upon the waste management practices known to be practiced by the 
chlorinated aliphatic industry for non-hazardous sludges. Based on 
survey results, these practices are:
     On-site land treatment (one facility),
     On-site disposal in a non-hazardous landfill (two 
facilities),
     On-site co-disposal in a hazardous waste landfill (one 
facility), and
     Off-site disposal in a subtitle D landfill (7 facilities).
    As explained earlier, EPA modeled risks from two management 
scenarios,

[[Page 46507]]

an off-site non-hazardous municipal landfill, and a land treatment 
unit. The management practices of most concern (landfills and land 
treatment) were assessed for this waste. Other non-hazardous waste 
management practices currently are not used by industry and would not 
serve as an appropriate basis for listing the waste as hazardous. In 
the case of the management practices employed by this industry, we are 
confident that the risk estimates from modeling an off-site non-
hazardous waste landfill scenario also are representative of the 
potential risks associated with the management of EDC/VCM wastewater 
treatment sludges in on-site landfills. This is because information 
provided in facility responses to the RCRA Section 3007 questionnaire 
indicate that EDC/VCM wastewater treatment sludges are co-disposed with 
other industrial non-hazardous wastes in on-site landfills, therefore 
these units can be treated as off-site landfills (that receive a 
variety of wastestreams) rather than as monofills (that receive only 
one type of waste) with regard to the risk modeling approach employed.
    Land treatment. The Agency's risk assessment of EDC/VCM wastewater 
treatment sludge showed risks of concern for the land treatment 
management scenario. The contaminant of greatest concern is dioxin. The 
exposure routes of concern are airborne releases and surface erosion 
from runoff which result in contamination of food products from nearby 
agricultural operations. The sludges present a hazard due to the fact 
that land treatment units are not covered and due to the potential 
absence of runoff controls. Land treatment results in a high-end cancer 
risk for the farmer of 2E-4 and a central tendency risk of 4E-6. EPA 
also performed a Monte Carlo analysis, and the results showed a risk 
for the farmer of 1E-4 at the 90th percentile, and 7E-6 at the 50th 
percentile. The high-end deterministic risk falls within the risk range 
for which there is a presumption for listing the waste as hazardous, 
consistent with guidance the Agency has used for determining that a 
waste is hazardous (see 59 FR at 66077), i.e., the risks associated 
with management of EDC/VCM sludge in a land treatment unit are 1E-4 or 
higher, and well above the 1E-5 listing benchmark. The probabilistic 
results confirm that the high-end deterministic risk (2E-4) is above 
the 90th percentile result (1E-4). The 1992 guidance (memorandum from 
the then Deputy Administrator F. Henry Habicht ``Guidance on Risk 
Characterization for Risk Managers and Risk Assessors'') states that 
``[t]he `high end' of the risk distribution [generally the area of 
concern for risk managers] is conceptually above the 90th percentile of 
the actual (either measured or estimated) distribution. This conceptual 
range is not meant to precisely define the limits of this descriptor, 
but should be used by the assessor as a target range for characterizing 
`high-end risk'.'' Therefore, a high-end estimate that falls within the 
range (above the 90th percentile but still realistically on the 
distribution) is a reasonable basis for a decision. Therefore, EDC/VCM 
sludges managed in a land treatment unit pose risks that support a 
proposed listing determination for these wastes.
    As discussed previously, the risk assessment addresses nine of the 
listing criteria in 40 CFR 261.11. EPA believes the risks resulting 
from our analysis represent plausible management of EDC/VCM sludges 
(261.11(a)(3)(vii)) using reasonable assumptions for management in land 
treatment units. In addition, the risk analysis was developed using 
actual analytical data.
    Of lesser concern, but still within our discretionary risk range, 
are the potential health effects associated with arsenic in EDC/VCM 
wastewater treatment sludges that are managed in land treatment units. 
We found that arsenic presents some risk from potential releases to 
groundwater from the land treatment unit. For the arsenic groundwater 
pathway, land treatment results in a high-end cancer risk of 1E-05 and 
a central tendency risk of 8E-07. However, the predicted time period 
for the peak arsenic concentration to reach a receptor well is 1,500 
years. In addition, our modeled leachate concentrations for arsenic 
result in predicted receptor well concentrations of 0.5 ppb (high end) 
and 0.2 ppb (central tendency). By comparison, the average background 
concentration of arsenic in rain derived from terrestrial air masses is 
0.46 ppb.34 Therefore, EPA does not believe that the risk 
from arsenic in this waste is significant, as discussed below.
---------------------------------------------------------------------------

    \34\ Andreae, M.O. 1980. Arsenic in Rain and the Atmospheric 
Mass Balance of Arsenic. Journal of Geophysical Research. v.85, pp. 
4512-4518, as cited in Welch, A.H., M.S. Lico, and J.L. Hughes. 
1988. Arsenic in Ground Water of the Western United States. Ground 
Water, v.26, n.3, pp. 333-347.
---------------------------------------------------------------------------

    Even though the high-end cancer risk from arsenic is within the 
general action level risk range (i.e., 1E-04 to 1E-06), the central 
tendency risk falls outside this range. Another factor that the Agency 
considered when evaluating the potential risks from arsenic in this 
wastestream is the significant period of time it is predicted to take 
for the concentration of arsenic in a receptor well to reach the peak 
concentration level (i.e., 1,500 years). Given these factors, the 
Agency concludes that the risk posed from potential releases of arsenic 
in this wastestream when managed in land treatment units is marginal, 
and in itself does not warrant listing the waste as hazardous. The 
Agency therefore is proposing to list EDC/VCM wastewater treatment 
sludges based solely on the presence of dioxin and the potential risk 
associated with dioxin when this waste is managed in land treatment 
units. As outlined in the preamble to the Agency's proposed listing 
determination for wastes generated by the Dyes and Pigments Industry, 
listing determinations for wastestreams for which risks are calculated 
to be 1E-04 or higher are considered to pose a substantial present or 
potential hazard to human health and the environment and are listed as 
hazardous.
    Landfill. The Agency's risk assessment showed no significant risks 
associated with dioxin, and only marginal risk associated with 
potential groundwater releases of arsenic in the off-site landfill 
scenario. The risk assessment showed a high-end cancer risk from 
arsenic of 3E-05 and a central tendency risk of 9E-07. However, these 
risks levels are associated with a peak arsenic concentration in a 
receptor well that is predicted to occur only after a period of 8,800 
years. Predicted high end arsenic concentration at a receptor well is 
1.4 ppb and the central tendency arsenic concentration in a receptor 
well is 0.2 ppb. This level of arsenic contamination is very close to 
average background exposure levels for arsenic. As mentioned above, the 
current average background concentration of arsenic in rain derived 
from terrestrial air masses is 0.46 ppb. Average background exposure to 
inorganic arsenic is 14 ug/day from food, and 5 to 7 ug/L from water. 
EPA's modeling results indicate that the disposal of EDC/VCM sludge in 
an unlined landfill could (over a period of 8,800 years) increase the 
concentration of arsenic in groundwater in a downgradient well (102 
meters from the landfill) by only 1.4 ug/L and would add approximately 
2 ug/day of arsenic to the average daily exposure level (about 20 ug/
day) for the highly exposed individual. Actual potential level of risk 
would be lower than those predicted by our modeling efforts, if the 
sludges are disposed in lined landfills.
    Given that the Agency's risk assessment indicates potential risk 
within our discretionary range

[[Page 46508]]

associated with a peak arsenic concentration in a receptor well that is 
predicted to occur only after a period of 8,800 years, and given the 
absence of significant risk from any other constituents of concern, EPA 
concludes that EDC/VCM wastewater treatment sludges do not pose a 
significant risk when managed in landfills.
    Based upon the Agency's findings that EDC/VCM wastewater treatment 
sludges pose significant risks when managed in land treatment units but 
pose no significant risks when managed in landfills, the Agency is 
proposing a ``contingent management listing'' for this waste. EPA is 
proposing to list EDC/VCM wastewater treatment sludges as hazardous, 
unless the sludges are managed in landfills. Again, the Agency is 
proposing this listing determination based upon the fact that our risk 
assessment results for the land treatment unit scenario indicate a 
level of risk of 2E-04, well above the 1E-5 risk level the Agency uses 
as guidance in making listing determinations.
c. Why Is EPA Proposing a Contingent Management Approach as Most 
Appropriate for EDC/VCM Wastewater Treatment Sludges?
    The Agency's analysis of the risks associated with EDC/VCM 
wastewater treatment sludges shows that one of the current waste 
management practices (land treatment) results in significant risk while 
the other primary management practice (disposal in subtitle D landfill) 
shows little risk. Therefore, the Agency is proposing to list EDC/VCM 
wastewater treatment sludges as EPA Hazardous Waste Number K174, unless 
the sludges are managed in a subtitle C or subtitle D landfill. The 
Agency believes that allowing the waste to continue to be managed under 
a low risk management scenario (i.e., subtitle D landfilling) outside 
of the subtitle C system achieves protection of human health and the 
environment, and that little additional benefit would be gained by 
requiring that all EDC/VCM wastewater treatment sludges be managed in 
accordance with RCRA subtitle C management standards. Given the 
Agency's finding that no significant risks are posed from managing EDC/
VCM wastewater treatment sludges in a landfill, the Agency sees no 
reason to include sludges managed in this manner in the scope of the 
hazardous waste listing. Additionally (and after consideration of the 
predicted risk differential between land treatment and landfilling), 
because only one facility identified in the RCRA Section 3007 Survey 
employs land treatment for these wastes, this practice is somewhat 
anomalous compared with land disposal. It does not make sense to apply 
a traditional listing approach (i.e., list all wastes regardless of 
management practice) based upon a practice occurring at one facility, 
especially if a more tailored listing can prevent this risk.
    A contingent management listing approach is within EPA's statutory 
authority. See Military Toxics Project v. EPA, 146 F.3d 948 (D.C. Cir. 
1998). The Agency believes that making a listing determination that is 
tailored to specific waste management practices is particularly 
appropriate under these circumstances, where the management practices 
identified are clear and very easily distinguished (such as the 
difference between land treatment and land disposal), and the 
differences in risk presented by these practices are clearly defined. 
In the case of EDC/VCM wastewater treatment sludges, EPA believes that 
an opportunity exists to establish a conditional management listing for 
these sludges that will reduce the risks associated with unsafe waste 
management practices, while not imposing significant incremental costs 
upon generators managing the wastes in a manner that does not pose 
significant risk. While disposal of EDC/VCM wastewater treatment 
sludges in land treatment units is projected to pose significant risks, 
the disposal of these sludges in landfills does not result in 
significant risks. This arises because the constituent of most concern, 
dioxin/TCDD, is relatively immobile in groundwater. However, risks from 
this constituent can be significant if the waste is managed in a manner 
that does not control for airborne releases or surface erosion from 
runoff, both of which are better controlled at landfills. Therefore, 
EPA believes a contingent management listing for this waste is a 
preferable and permissible alternative to simply listing all EDC/VCM 
wastewater treatment sludges as hazardous wastes.
    The Agency's proposed listing description for EDC/VCM wastewater 
treatment sludges that will define this waste as hazardous unless the 
waste is managed in a landfill is as follows:

K174  Wastewater treatment sludges from the production of ethylene 
dichloride or vinyl chloride monomer, unless the sludges meet the 
following conditions: (i) they are disposed of in a subtitle C or D 
landfill licensed or permitted by the state or federal government; 
(ii) they are not otherwise placed on the land prior to final 
disposal; and (iii) the generator maintains documentation 
demonstrating that the waste was either disposed of in an on-site 
landfill or consigned to a transporter or disposal facility that 
provided a written commitment to dispose of the waste in an off-site 
landfill. Respondents in any action brought to enforce the 
requirements of subtitle C must, upon a showing by the government 
that the respondent managed wastewater treatment sludges from the 
production of vinyl chloride monomer or ethylene dichloride, 
demonstrate that they meet the terms of the exclusion set forth 
above. In doing so, they must provide appropriate documentation 
(e.g., contracts between the generator and the landfill owner/
operator, invoices documenting delivery of waste to landfill, etc.) 
that the terms of the exclusion were met.
d. How Will This Contingent Management Listing Be Implemented?
    Under this proposed listing, EDC/VCM wastewater treatment sludges 
will be hazardous wastes if managed by any method except disposal in a 
landfill. EPA has a clear interest in ensuring that these sludges are 
in fact disposed in a landfill, or else they would be listed hazardous 
waste at the point of generation. The Agency also has an interest in 
making sure that accurate records are kept to facilitate enforcement.
    The Agency notes that based on the RCRA Section 3007 questionnaire 
results (which surveyed the universe of chlorinated aliphatics 
production facilities in the United States), the predominant management 
practice used for these wastes is disposal in a landfill, while one 
facility currently uses a land treatment facility. It is difficult for 
EPA to foresee a change in this well-established management practice. 
Therefore the Agency believes it is unlikely that these sludges will be 
sent to any type of facility other than a landfill, particularly if the 
approach proposed in today's rule is promulgated. Generators who choose 
to manage these sludges at non-landfill facilities must define their 
sludges as listed hazardous waste at the point of generation and manage 
them accordingly.
    The Agency also is restricting the placement of EDC/VCM wastewater 
treatment sludges on the ground prior to

[[Page 46509]]

their being disposed in a landfill (e.g., storage in waste piles, 
spills). EPA wants to ensure that these wastes, which are clearly 
capable of presenting unacceptable risk if improperly managed, are 
managed only in the manner found to be protective of human health and 
the environment.
    Generators, and other parties involved in the management of EDC/VCM 
wastewater treatment sludges, claiming that their wastes fall outside 
the scope of the hazardous waste listing must be able to demonstrate 
that sludges excluded from the listing description are being managed in 
accordance with all of the conditions for being excluded from the 
listing. This means that parties claiming the waste falls outside the 
scope of subtitle C must be able to demonstrate that (1) previously 
generated and managed waste (which is being claimed as not meeting the 
K174 listing) was disposed of in a landfill; and (2) waste currently 
being managed is not being stored, or otherwise managed, on the land 
(e.g., landfarms, waste piles) as well as demonstrate that the waste 
will be disposed of in a landfill (e.g., have a contract in place with 
a landfill owner/operator that specifies intent to manage EDC/VCM 
sludges at the landfill facility). To further clarify how today's 
proposed approach would be implemented, below we describe these two 
distinct situations where a listing determination will be made under 
this proposed approach.
i. EDC/VCM Sludges Sent Off-Site
    Under the proposed contingent management listing for K174, EDC/VCM 
sludges that already have been shipped from the generator facility to a 
subtitle C or subtitle D landfill were never a listed hazardous waste. 
In this instance, should a question arise as to the status of sludges 
previous shipped off-site, the implementing agency would look to 
indications such as contracts between the generator and the landfill 
owner/operator, invoices showing waste was delivered to a specific 
landfill, and other documents that clearly show the waste was 
transferred to a subtitle C or subtitle D landfill.
ii. EDC/VCM Sludges at Generator Site
    In this situation, determining whether or not an EDC/VCM sludge 
meets the proposed K174 listing would be done in a prospective manner, 
not unlike many of the existing regulatory exclusions from the 
definition of solid waste (where determinations of whether or not a 
material is a waste are often based upon how the waste will be managed, 
i.e., recycled. See, for example, requirements at 40 CFR 261.2, Table 
1, and 261.4(b)). Under the existing generator requirements in 40 CFR 
Part 262, generators of solid waste must determine whether the waste is 
a listed hazardous waste (40 CFR 262.11(b)). Determinations made by 
generators regarding whether their EDC/VCM sludges are listed (where 
these sludges have not yet been disposed of off site in an appropriate 
landfill) will be made by virtue of where the waste will be sent. In 
situations where the implementing agency is questioning any claims by 
the generator of the non-listed status of sludges being stored on site, 
the generator should be able to show that there is an agreement already 
in place with a transporter and/or landfill indicating that these 
sludges will be delivered to a landfill. It is the EPA's experience 
that wastes cannot usually be shipped to a commercial landfill without 
first establishing a relationship with that landfill, where factors 
such as the amount of waste, the frequency of shipments, the physical 
and chemical make up of the waste, etc., are agreed upon before the 
waste ever arrives at the landfill.
    In the case of generators who manage EDC/VCM in on-site landfills, 
the Agency requests comment on the types of records or documentation 
that may be used to verify or document that the waste is managed in the 
on-site landfill and not managed in a land treatment unit.
    The Agency notes that it is not our intent to condition the 
regulatory status of the waste upon a recordkeeping or paperwork 
requirement. The Agency believes that the ability to demonstrate the 
commitment to dispose of the waste in a landfill is necessary to ensure 
the waste falls outside the scope of the listing. We do not believe 
that any specific recordkeeping requirement (e.g., the completion and 
retention of a specific form) is necessary to make this demonstration. 
We believe that documentation of previous landfilling of the waste and 
a demonstration of a commitment to dispose of currently generated waste 
in a landfill may be made by several means. EPA is requesting comment 
on the types of records and/or documentation normally kept by 
generators and/or disposal facility owner/operators that may be used to 
make such demonstrations (see section III.E.2.f. below).
    EDC/VCM wastewater treatment sludges that are not listed hazardous 
waste due to contingent management will be considered nonhazardous from 
their point of generation. As a result, such sludges will not be 
subject to RCRA subtitle C management requirements for generation, 
transport, or disposal (including the land disposal restrictions), if 
the waste is destined for disposal in a landfill (and the generator can 
demonstrate such intention).
    Of course, if the waste is not disposed of in such a unit, then the 
exemption would no longer apply and the waste would have to be managed 
in compliance with subtitle C management requirements, from the point 
of generation. In other words, if the Agency finds that the waste is 
disposed of in a unit other than a subtitle C or D landfill, the Agency 
may cite the generator of the waste as being out of compliance with all 
applicable subtitle C management requirements. The Agency also points 
out that should EDC/VCM wastewater treatment sludges meet the listing 
description for another hazardous waste listing, or if the wastewater 
treatment sludges exhibit one or more of the characteristics of 
hazardous waste, the sludges must be managed as hazardous wastes and 
are not exempt from regulation under today's listing determination, 
regardless of how the sludges are managed.
e. What Specific Comments Is EPA Requesting on Implementation of the 
Contingent Management Listing Approach?
    The Agency requests comments on this proposed contingent management 
listing approach, and may make changes to the implementation approach 
based on comments received. EPA notes that this contingent management 
approach necessitates that the Agency have the ability to confirm 
whether or not wastes claimed to fall outside the scope of the listing 
description are disposed of in a landfill as required by the proposed 
listing determination. As a result, some type of documentation or 
demonstration that the waste actually is disposed of in a landfill (or 
will be disposed of this way) is appropriate.
    EPA is proposing that generators be able to provide documentation 
that waste previously generated (for which the claim is made that the 
waste is not K174) was disposed in an on-site landfill or transported 
to and received by an off-site landfill. In addition, a generator must 
be able to demonstrate that waste currently present at the generator's 
facility will be disposed in an on-site or off-site landfill, and that 
the waste will not be stored, or otherwise managed, on the land prior 
to disposal in a landfill. Appropriate types of documentation that may 
fulfill these requirements may include: contracts between a generator 
and a landfill owner/operator, invoices documenting that the waste was 
transported to and received by a landfill facility, bills of

[[Page 46510]]

lading or other shipping papers that clearly indicate the type and 
quantity of waste shipped off-site, the date of shipment, the name and 
address of the landfill receiving the waste, and the date the waste was 
received by the landfill.
    EPA requests comment on the type of records, documentation, and 
demonstrations that may be adequate for determining compliance with the 
contingent management listing. EPA requests comment on what type of 
internal records may be kept by solid waste generators that may 
demonstrate intended management of the waste and whether such records 
are adequate for demonstrating compliance with the contingent 
management conditions for exclusion from the hazardous waste listing. 
EPA also requests comment on its proposal that waste that does not meet 
the terms of the conditional listing is hazardous from the point of 
generation.
3. VCM-A Wastewater Treatment Sludges
a. Is EPA Proposing To Regulate VCM-A Wastewater Treatment Sludges?
    Yes, EPA is proposing to list as hazardous wastewater treatment 
sludge from the production of vinyl chloride monomer using mercuric 
chloride catalyst in an acetylene-based process (VCM-A). The sludge is 
generated at one facility as a result of treating water running off an 
area where spent mercury catalysts are removed from the VCM-A 
production process. The Agency has concluded that the waste meets the 
listing criteria in 40 CFR 261.11(a)(3) and is capable of posing a 
substantial present or potential hazard to human health and the 
environment if mismanaged. For reasons explained in more detail below, 
EPA is proposing two alternative approaches for listing this waste as 
hazardous. The Agency is requesting comment on both proposed 
approaches.
b. What Information Led EPA To Propose To List as Hazardous VCM-A 
Wastewater Treatment Sludges?
i. Background
    As previously described in today's proposed rule, the manufacture 
of vinyl chloride monomer in an acetylene-based process using mercuric 
chloride catalysts generates non-process wastewaters as a result of 
precipitation runoff in the production area, as well as from using 
water to remove spent catalyst from the reactors. Because of its high 
mercuric chloride content, this wastewater is collected and treated in 
a dedicated non-biological treatment system that uses sodium sulfide to 
convert the mercuric chloride to mercuric sulfide, which precipitates 
as a sludge and is dewatered to form a filter cake. This treatment 
system is operated in a batch-process fashion, and treated effluent is 
discharged under the facility's NPDES permit. EPA knows of only one 
facility in the United States that operates an acetylene-based VCM 
production process. According to the facility's response to the RCRA 
Section 3007 survey, this waste was sent to a permitted hazardous waste 
landfill for disposal in 1996. Other information provided by the 
facility in response to a separate RCRA Section 3007 request from EPA 
indicates this waste was sent to the same permitted hazardous waste 
landfill from 1990 to 1994 as well. The facility generates 
approximately 120 metric tons of VCM-A wastewater treatment sludge per 
year.
ii. Analytical Results
    EPA analyzed one sample of this sludge in 1996 in support of this 
listing determination. The analytical results showed the sludge 
contained 9,200 mg/kg total mercury, and 0.26 mg/L in leachate using 
TCLP. The results for a split sample analyzed by the facility were 
17,700 ppm total mercury, and the TCLP result was 0.654 mg/L. These 
results indicate a very high total mercury concentration (approximately 
one to two percent of the waste is mercury), and the TCLP results 
exceed the regulatory level for the mercury toxicity characteristic of 
0.2 mg/L. Data generated by EPA in support of a treatability study on 
this particular waste showed a total mercury concentration (in aliquots 
of a single sample) ranging from approximately 3,000 to 9,000 mg/kg, 
and TCLP results were all below the regulatory limit.35 
Other data available to EPA from the facility indicate that 
approximately 20 percent of the tested samples exceed the regulatory 
level for mercury 36.
---------------------------------------------------------------------------

    \35\ Paul Bishop, Renee A. Rauche, Linda A. Rieser, Markram T. 
Suidan, and Jain Zhang; ``Stabilization and Testing of Mercury 
Containing Wastes,'' Draft, Department of Civil and Environmental 
Engineering, University of Cincinnati, March 31, 1999. Please note 
that this is a draft EPA document not yet peer reviewed. Also, data 
within the report is still undergoing QA/QC review, and the text, 
data, and conclusions in the report may change before the document 
is finalized.
    \36\ Summary of Mercury TCLP Data on VCM-A Sludge from Borden 
Chemicals and Plastics, EPA July 1999.
---------------------------------------------------------------------------

iii. Assessment of Potential Risk
    EPA's quantitative analysis of the potential groundwater risks 
posed by this waste assumes waste disposal in an unlined landfill. The 
Agency is making use of previously conducted groundwater modeling and 
risk analyses for the proposed Hazardous Waste Identification Rule (60 
FR 66344, December 21, 1995) that resulted in an estimated dilution and 
attenuation factor (DAF) for mercury of 40. Using this DAF and the 
mercury leachate concentration of the VCM-A sludge analyzed by EPA 
(0.26 mg/L), the expected concentration of mercury at a modeled 
receptor well (after a release to groundwater from an unlined landfill) 
exceeds the maximum contaminant level (MCL) for mercury (0.002 mg/L) by 
a factor of three. Using the mercury leachate concentration from the 
facility's split sample (0.654 mg/L), the mercury MCL would be exceeded 
at a modeled receptor well by a factor of eight.
    EPA is unable to quantitatively assess the potential risk this 
waste poses when disposed in a subtitle C landfill without prior 
treatment. However, we qualitatively considered the risk associated 
with such a management scenario. There is considerable uncertainty 
about the performance of engineered landfills. In the near term, 
especially at regulated subtitle C landfills, there are quality 
assurance controls to reduce the likelihood of significant material, 
installation, or facility operation errors that could degrade 
performance of the engineered systems. In addition, such landfills have 
ground water monitoring and leachate management controls to further 
reduce the chances of significant ground water risk. However, in the 
long-term, there is considerable uncertainty as to how well engineered 
systems will operate and whether there will continue to be long-term 
care and maintenance after the regulatory post-closure period ends. EPA 
can only qualitatively consider the potential long-term risk of wastes 
in subtitle C landfills. However, we considered the above mentioned 
uncertainties, along with the quantitative estimates of potential risk 
in unlined landfills, when assessing the potential risks of managing 
untreated wastes in a subtitle C landfill, such as VCM-A sludges that 
contain persistent constituents such as mercury.
iv. Rationale for Proposed Hazardous Waste Listing Determination
    EPA is proposing two rationales to ``list'' this waste as 
hazardous, both of which lead the Agency to conclude we should propose 
to list this wastestream as hazardous waste. First, EPA believes it is 
plausible that this waste may be mismanaged and disposed of in an 
unlined and uncovered landfill and that it is capable of posing a 
substantial

[[Page 46511]]

hazard if so managed. Second, based upon information EPA has, including 
information on liner performance and the mobility of mercury under 
certain pH conditions, EPA believes that even when disposed of in a 
landfill that is compliant with Subtitle C landfill standards, this 
waste is likely to leach significant quantities and concentrations of 
mercury that long-term degradation of the landfill's leachate control 
systems (especially after post-closure care has ended) would plausibly 
cause an unacceptable release of mercury into groundwater and has the 
potential to pose a substantial hazard when this waste is so managed 
without improved prior treatment. EPA requests comment on the basis for 
the rationales described above, both for the disposal scenario in an 
unlined landfill, and the disposal scenario in a landfill compliant 
with subtitle C landfill standards.
    The Agency's analysis of potential risk indicates that disposal of 
the VCM-A sludge in an unlined landfill may result in risks due to the 
migration of mercury in groundwater to a receptor well in 
concentrations that exceed the MCL for this constituent. The Agency 
notes that the single facility generating this waste reports managing 
the waste by disposing of it in a subtitle C landfill for certain 
years. Therefore, a simple conclusion may be to dismiss the potential 
risk for the groundwater pathway (assuming it continues to go to a 
subtitle C landfill) due to the presence of a landfill liner and 
leachate collection. In addition, (as mentioned previously) the mercury 
in the waste is in the form of mercuric sulfide, which generally is 
found to be a relatively insoluble form of mercury (indicated by only a 
relatively small percentage of the total mercury content of the waste 
leaching under the TCLP). However, data recently collected by the 
Agency and preliminary results from the analysis of this waste indicate 
that this waste may not behave in the same manner (in terms of the 
mobility of mercury in sulfidic form) in all environments. As discussed 
briefly below (and further in the Land Disposal Restrictions, Section 
V.F.), available data indicate that although the mercury in the VCM-A 
sludge remains relatively immobile at pH levels of 6 or lower, higher 
pH conditions will result in mercury mobilizing to the aqueous 
phase.37
---------------------------------------------------------------------------

    \37\ 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.
---------------------------------------------------------------------------

    Using data from a collected sample of the VCM-A wastewater 
treatment sludge, constant pH leaching tests were conducted on the 
waste sample to determine the effect pH has on the stability of the 
waste. The preliminary results of the constant pH leaching tests showed 
that mercury leachate concentrations were lower in samples leached at a 
pH of 6.0 or lower (e.g., 0.00582 mg/L at pH=6 after 24 hours), 
compared with concentrations at higher pH conditions. The same sample 
leached at pH of 10 produced a significantly higher mercury leachate 
concentration of 1.63 mg/L after 24 hours.38
---------------------------------------------------------------------------

    \38\ Paul Bishop, op. cit., p. 14.
---------------------------------------------------------------------------

    Information obtained by EPA on the pH levels of actual leachate 
collected from the landfill cell in which the VCM-A wastewater 
treatment sludge currently is disposed show that the pH is greater than 
9.39 If this pH value is indeed indicative of the disposal 
environment for this waste, then based upon the pH relationship 
identified in the preliminary results of constant pH leach tests 
described above, one would predict that the mercury would be 
significantly mobilized under the disposal environment actually being 
used for this waste.
---------------------------------------------------------------------------

    \39\ E-mail communication to John Austin, U.S. EPA, from Mitch 
Hahn, Waste Management Corporation, April 14, 1999.
---------------------------------------------------------------------------

    In summary, although the waste is disposed in a subtitle C 
landfill, the fact that the mercury in the waste may mobilize at pH 
levels greater than 6 means that the leach test results may under 
predict concentrations in leachate. In case of significant leachate 
contamination, the landfill liner may be the only guard against the 
release of mercury to the environment (due to the fact that the waste 
is not stable in this landfill disposal scenario). Should the liner 
fail, mercury present in the leachate would be released to the 
environment.
    EPA acknowledges that a liner/leachate collection system in a 
subtitle C unit serves to contain and remove waste leachate and 
provides important environmental protection. However, EPA recognizes 
that there is inherent uncertainty in such systems, and it believes 
that the purpose of the RCRA hazardous waste treatment requirements (as 
expressed by Congress) is to reduce the uncertainty inherent in 
engineered containment approaches. EPA believes that waste containment 
systems will tend to degrade with time. Eventually, synthetic liners 
will degrade and leachate collection systems will cease operation. As 
put forth in the proposed Liner and Leak Detection Rule (52 FR 20218, 
May 29, 1987), no liner can be expected to remain impervious forever. 
Properly installed double liner and leachate collection systems, 
together with final covers placed at closure, will substantially reduce 
releases during the operating life and post-closure care period. 
However, these technologies may not always reduce the longer-term risk 
for landfills to acceptable levels for persistent, mobile, and highly 
toxic compounds. This is because the containment system may not prevent 
leachate release from the landfill indefinitely, for example after the 
post-closure period, when active maintenance of the cap and leachate 
collection system may be reduced or may end. The Agency has found that 
treatment of the waste under the LDR standards of RCRA subtitle C will 
significantly reduce potential risks from the disposal of this waste 
over the long term. This is particularly important for a constituent 
such as mercury, that is persistent and does not degrade. Treatment in 
accordance with prescribed BDAT can reduce the possibility that 
leachable mercury is available for release to the environment. Again, a 
liner/leachate collection system in a subtitle C unit is expected to 
contain waste leachate and lessen the risk while such a system is 
intact. However, even assuming a low probability of failure, because 
the TCLP may be significantly under predicting leachability for this 
waste in this subtitle C disposal scenario, there may still be a 
release of mercury that results in an exceedance of the MCL. While 
there are uncertainties in this assessment, it still illustrates that 
the mercury concentrations in the receptor well may be close to, and 
could even be higher than the MCL. Given the well-documented toxicity 
and persistence of mercury, the potential for greater mobility of 
mercury from this particular waste in a subtitle C landfill (than 
predicted by the TCLP), and the uncertainties associated with 
engineered landfills over the long-term--as reflected in statutory 
language regarding treatment requirements--EPA believes that the 
disposal of this waste, untreated, in a subtitle C landfill may not be 
protective and therefore may warrant listing the waste as hazardous.
    In EPA's view, it may violate Congressional intent to allow a waste 
that the Agency otherwise would list as hazardous (absent the fact that 
the waste is managed untreated in a Subtitle C landfill) to be disposed 
in a hazardous waste landfill under conditions that may result in the 
hazardous constituents

[[Page 46512]]

in the waste leaching from the waste (due to the high pH of the 
landfill environment). Congress clearly expressed its intent that the 
Agency is not to place excessive reliance or confidence in landfill 
design and liners for problematic wastes. In the Hazardous and Solid 
Waste Amendments (HSWA) of 1984, Congress explicitly added as one of 
the ``findings'' to RCRA that ``land disposal facilities are not 
capable of assuring long-term containment of certain hazardous wastes'' 
and that ``reliance on land disposal should be minimized or 
eliminated.'' 40 As a result of this finding, and others, 
Congress added the land disposal restriction program to RCRA, which 
significantly restricts land disposal of hazardous wastes and provided 
in section 3004(m) the mandate that EPA develop treatment standards for 
``diminishing the toxicity of wastes or substantially reducing the 
likelihood of migration of hazardous constituents from the waste so 
that short-term and long-term threats to human health and the 
environment are minimized.'' In addition, the legislative history to 
RCRA section 3004(m) states that this section ``makes Congressional 
intent clear that land disposal without prior treatment of these wastes 
with significant concentrations of highly persistent, bioaccumulative 
constituents is not protective of human health and the environment.'' 
(130 Cong. Rec. S 9178; daily ed. July 25, 1984). Were we to propose a 
no list determination for this waste based solely upon the fact that 
this waste currently is disposed in a subtitle C landfill--ignoring the 
high levels of total mercury in the waste, its potential for leaching 
(at high pH), and the likely benefits of treatment--we would be 
bypassing Congressional intent that wastes be treated to reduce 
toxicity and/or migration of hazardous constituents before final 
disposal.
---------------------------------------------------------------------------

    \40\ RCRA section 1002(b)(7), 42 U.S.C. 6902(b)(7).
---------------------------------------------------------------------------

    EPA views the statute and legislative history as sufficient 
justification to evaluate in a listing determination all risks of land 
disposal, including in appropriate cases problems that might be 
associated with voluntary disposal of untreated wastes in permitted 
subtitle C facilities. This is particularly true where risks presented 
by a waste will be high if releases occur, if the waste is highly 
persistent, and treatment of the waste under subtitle C would 
significantly reduce these risks. In the case of the VCM-A wastewater 
treatment sludges, the potential risks presented by the high content of 
mercury in the waste if a release should occur, warrants the imposition 
of treatment standards in accordance with Congress's intent. Although 
the generator currently sends VCM-A wastewater treatment sludges to a 
lined subtitle C landfill facility, we believe that substantial risks 
are plausible, given the possibility of eventual landfill degradation 
or failure. The estimated risks due to migration from an unlined 
landfill provide an indication of the potential risks that will occur 
if mercury is released from the lined landfill due to failure of the 
unit to contain the waste leachate over time.
    Absent a hazardous waste listing, the Agency has no mechanism for 
requiring that the waste be treated prior to disposal to ensure that 
the mercury in the waste does not leach from the waste to the 
surrounding environment (and hence provide some protection of human 
health and the environment in the event of a liner failure). 
Furthermore, the Agency has little assurance that the waste will 
continue to be managed in a subtitle C landfill.
    Listing a waste as hazardous provides a level of certainty with 
regard to the management and stewardship of a waste as well. Given the 
quantity of mercury contained in the VCM-A wastewater treatment sludge 
and the potential solubility of this large quantity of mercury, the 
Agency tentatively concludes that it is appropriate that the waste be 
managed in accordance with the ``cradle-to-grave'' management system 
established under RCRA Subtitle C. By listing this waste as hazardous, 
EPA and the general public are afforded a greater level of certainty 
with respect to the manner in which the waste must be managed. It will 
have to be accumulated and stored in closed containers, sent off-site 
for treatment and disposal within a relatively short time of the time 
it was generated, transported by a registered hazardous waste 
transporter and accompanied by a manifest, and treated and disposed at 
facilities permitted to handle hazardous wastes.
    The Agency bases its listing determinations on an evaluation of 
risks from plausible management practices. For the reasons just 
described, EPA believes that disposal of untreated VCM-A sludge in a 
subtitle C landfill represents one plausible management scenario and 
that this scenario could lead to significant problems. Equally 
important, the Agency questions whether the current waste management 
practices are the only practices that will be employed by the facility 
in the future. That is, the Agency believes other management practices 
are plausible. First, information available to the Agency documents 
only that the facility has sent VCM-A wastewater treatment sludges to a 
subtitle C landfill for disposal for some periods after 1990. 
Specifically, information provided by the facility in response to a 
specific RCRA Section 3007 request from EPA indicates this waste was 
sent to a subtitle C landfill from 1990 to 1994; and according to the 
facility's response to the RCRA Section 3007 survey, this waste was 
sent to a permitted hazardous waste landfill for disposal in 1996. In 
addition, we have no information with regard to the disposal of the 
waste prior to 1990. The Agency does know that the facility had as many 
as 800 drums of the mercuric sulfide sludge stored on site in 1985; 
however the Agency has no information with regard to the ultimate 
management of the waste.41 Given the fact that the Agency 
does not have a complete record of how the VCM-A sludge was managed in 
the past, the Agency believes that it is reasonable to assume that the 
VCM-A sludge may be managed in an non-subtitle C landfill in the 
future.
---------------------------------------------------------------------------

    \41\ ``Reclassification Petition'' submitted to Louisiana 
Department of Environmental Quality, Hazardous Waste Division, by 
Borden Chemical, September, 1987, p. III-2.
---------------------------------------------------------------------------

    Therefore, for the purposes of assessing potential risk, the Agency 
believes a plausible mismanagement scenario can also include an unlined 
landfill, the scenario in which the Agency's risk analysis indicates a 
potential for the concentration of mercury at a modeled receptor well 
to be as much as eight times higher than the MCL for mercury (based 
upon the TCLP results and a DAF of 40).
    Our assessment includes predicted exceedances of the MCL (based 
upon the record sample EPA collected) assuming disposal in an unlined 
landfill; and a qualitative consideration of the possible risks when 
disposed in a subtitle C landfill without better treatment. Although 
risk analyses provide one of the principal bases for a listing 
determination, estimates of risk levels do not represent the sole basis 
for a listing determination. Other factors generally are considered in 
making a listing decision. In fact, the Agency's listing decision 
policy uses a ``weight-of-evidence'' approach in which calculated risk 
information is a single key factor. Available risk values are assessed 
with all other data available to determine whether a waste is or is not 
a hazardous waste (see the discussion of EPA's hazardous waste listing 
determination policy in the proposed listing for wastes generated by 
the dye and pigment industries at 59 FR 66073, December 22, 1994). In 
our decision to propose to list this sludge as hazardous,

[[Page 46513]]

the Agency considered several factors, including the extensive 
documentation on the toxicity of mercury, as well as the other criteria 
listed in 261.11(a)(3) to arrive at a listing determination, as further 
summarized below.
    Mercury has been identified by several different governmental 
agencies, including EPA, the Agency for Toxic Substances and Disease 
Registry (ATSDR), the Food and Drug Administration (FDA), and the 
Occupational Safety and Health Administration (OSHA), as a significant 
human toxicant. Each of these Agency's has developed regulations, 
guidelines, and/or standards to protect people from the serious 
potential health effects of exposure to mercury. In addition, it also 
is well documented that mercury is persistent in the environment, does 
not degrade, and bioaccumulates in wildlife, particularly fish. Agency 
studies, including the recently published Mercury Study Report to 
Congress 42 have documented the neurotoxicity of mercury and 
the potential adverse human health and environmental effects that may 
result from the release of mercury to the environment. In addition, 
ATSDR has published a toxicological profile for mercury which examines, 
summarizes and interprets toxicological information and epidemiological 
evaluations on mercury.43 Research conducted by both EPA and 
ATSDR provides documentation of the highly toxic effects of human 
exposure to mercury. Human consumption of highly-contaminated food can 
produce overt mercury neurotoxicity. Neurotoxic effects from mercury 
contamination range from subtle decrements in motor skills and sensory 
ability at comparatively low doses to tremors, inability to walk, 
convulsions and death at extremely high exposures. Human consumption of 
fish or grain contaminated with high levels of mercury can result in 
permanent damage to the brain, kidneys and developing fetuses. Adverse 
effects of mercury on fish include death, reduced reproductive success, 
impaired growth and development and behavioral abnormalities. Exposure 
to mercury also can cause adverse effects in plants, birds and mammals. 
The extent and availability of toxicity assessments for mercury is 
relatively extensive (see EPA's ``Mercury Study Report to Congress'' 
and/or EPA's ``Action Plan for Mercury'') 44. Certainty with 
regard to the potential risks to human health and the environment from 
exposure to mercury is well documented. Mercury presents significant 
human health threats when released to the environment.
---------------------------------------------------------------------------

    \42\ U.S. Environmental Protection Agency (1997), EPA-452-R-97-
003-009.
    \43\ ``Toxicological Profile for Mercury,'' ATSDR, April, 1999; 
http://www.atsdr.cdc.gov/press/ma990419.html.
    \44\ ``Mercury Study Report to Congress,'' volumes I-VIII, EPA-
452/R-97-003, December 1997; and EPA Action Plan for Mercury 
(Atttachment 1 to ``An Agency-Wide Multi-media Strategy for Priority 
PBT Pollutants''), http://www.epa.gov/ttnuatw1/112nmerc/
mercury.html.
---------------------------------------------------------------------------

    Wastewater treatment sludges from the VCM-A process using mercuric 
chloride catalyst contain significant levels of total mercury. As 
mentioned previously, approximately 120 metric tons of the sludge, 
containing about one percent (or 1 MT) of mercury, is generated per 
year at a single facility. One metric ton of mercury is approximately 
20 times as much mercury as is received typically by a single municipal 
solid waste landfill from all sources in one year. EPA also notes that 
in this particular case, we believe the mercury is likely to be 
significantly leachable at pH levels of a typical hazardous waste 
landfill. The Agency considers this quantity of potentially leachable 
mercury generated from a single facility and disposed of off-site to be 
significant. As outlined in the Draft EPA Action Plan for Mercury 
45, and EPA's Waste Minimization National Plan 
46, it is important to the protection of human health and 
the environment that all anthropogenic sources of mercury emissions to 
the environment be minimized. Given the inherent risks associated with 
mercury, EPA believes it is necessary to ensure, to the greatest extent 
possible, that wastes containing significant quantities of mercury are 
safely managed and to guard against potential mismanagement.
---------------------------------------------------------------------------

    \45\ Attachment to A Multimedia Strategy for Priority 
Persistent, Bioaccumulative, and Toxic (PBT) Pollutants, November 
16, 1998, EPA 742/D98/001, http://www.epa.gov/opptintr/pbt/
pbtstrat.htm.
    \46\ Waste Minimization National Plan, US EPA, 1994, EPA530-R-
94-045, http://www.epa.gov/rgytgrnj/specinit/p2/volprog/wm.htm.
---------------------------------------------------------------------------

    Upon consideration of the factors enumerated in 40 CFR 261.11(a)(3) 
and those summarized in the 1994 Dyes and Pigments Proposed Rule for 
making a hazardous waste listing determination, EPA made the following 
conclusions with respect to this waste. In terms of waste 
characterization, data available on this waste indicate with relative 
consistency that the waste contains a significant amount of total 
mercury, regardless of variation in pH and leachable mercury. 
Furthermore, in this particular case, we believe that the mercury is 
likely to be more leachable than the TCLP test indicates. It is well 
documented that mercury is a human toxicant. Mercury is persistent in 
the environment, does not degrade, and bioaccumulates in wildlife, 
particularly fish. These conclusions correspond to the listing factors 
at 40 CFR Sections 261.11(a)(3)(i), (iv), (v), and (vi), respectively.
    After considering the listing factors in 261.11(a)(3), and in 
particular the factors at 261.11(a)(3)(i)-(vi) (which include potential 
risks to groundwater from unregulated disposal of this waste, the fact 
that mercury is a human toxicant, is persistent in the environment, 
does not degrade, bioaccumulates in wildlife, and is present in very 
high concentrations in this waste), as well as several of the 
``additional factors'' listed in the 1994 Proposed Rule for Wastes 
Generated by the Dyes and Pigments Industry, and taking into account 
the Agency's overall goals to reduce releases of mercury to the 
environment, EPA is proposing to list this waste as hazardous. The 
proposed listing description is shown below.

K175  Wastewater treatment sludges from the production of vinyl 
chloride monomer using mercuric chloride catalyst in an acetylene-
based process.

    The proposed listing of VCM-A wastewater treatment sludges, which 
contain substantial amounts of total mercury is, in effect, an 
extension of the Agency's policy with regard to mercury emissions. The 
Agency believes that listing these wastewater treatment sludges as 
hazardous will provide incentive for the facility to find ways to 
reduce the overall quantity of mercury-containing VCM-A sludges 
generated. EPA believes there may be opportunities for this type of 
reduction through improved catalyst handling practices. Improved 
handling practices may result in a reduction in the amount mercuric 
chloride released in and around the VCM-A process area where it becomes 
available for introduction to the wastewater treatment system. In turn, 
this reduction would result in an overall decrease in the amount of 
mercury available for potential release to the environment.
    Once a waste is listed as a hazardous waste, the waste is 
prohibited from land disposal unless it is treated in compliance with 
treatment standards established under the RCRA land disposal 
restrictions standards program. The mercuric sulfide sludge generated 
from the VCM-A production process is unique in that this waste contains 
a very high amount of total mercury, and the

[[Page 46514]]

mercury is present in the waste in a relatively insoluble form as 
measured using the TCLP. However, the preliminary findings of the EPA/
ORD study described above suggest that variability in the pH of the 
waste as generated, and higher pH conditions potentially encountered in 
the disposal unit where this waste is managed, can affect the stability 
of the VCM-A sludge when disposed in a subtitle C landfill. The Agency, 
therefore, is proposing specific LDR treatment standards for this waste 
to minimize the potential release of mercury to the environment from 
this waste. A discussion of the proposed BDAT treatment standards for 
newly listed VCM-A wastes is provided later in this notice.
c. What Alternative Is EPA Considering for a Proposed Listing 
Determination?
i. Summary of Alternative Listing Option
    The alternative listing option EPA is proposing today is to list 
the VCM-A wastewater treatment sludges as hazardous waste, unless the 
waste is disposed in a subtitle C landfill. In addition, under this 
alternative option, VCM-A wastewater treatment sludges that exhibit the 
toxicity characteristic for mercury will be listed as hazardous. In 
other words, this waste will not meet the proposed K175 listing 
description, and therefore will not be listed hazardous waste from the 
point of generation, so long as it is disposed in a subtitle C 
landfill, and it does not exhibit the TC for mercury.
ii. Rationale for Alternative Listing Option
    As described earlier, EPA believes that the VCM-A sludge meets the 
criteria for being listed as a hazardous waste, principally due to the 
high concentration of mercury, a highly toxic constituent, in this 
waste. Available information indicates that the direct disposal of 
untreated VCM-A sludge in a subtitle C landfill may result in a marked 
increase in the mobility of mercury, and that, should the liner system 
ultimately degrade, this mercury can be released to groundwater and 
potentially reach a receptor well in concentrations at the MCL. Also, 
the Agency believes that disposal of these wastes in an unlined 
landfill is a plausible mismanagement scenario, which would result in 
exceedances of the MCL by up to a factor of eight. The Agency is 
seeking comment on these tentative conclusions and this proposed 
listing determination. Should the Agency receive data or other 
information on the conclusions drawn by the Agency with regard to the 
management of the waste and the behavior of this waste in the 
environment, particularly with regard to the potential for the mercury 
in the waste to leach under conditions of high pH levels, the Agency 
will consider alternative approaches. For example, if direct disposal 
of untreated VCM-A sludge in a subtitle C landfill can be shown to be 
protective without further treatment of this waste, due to the relative 
insolubility of mercuric sulfide or expected long-term performance of 
subtitle C systems, EPA will consider a conditional listing of VCM-A. 
Such an conditional listing would specify that the wastewater treatment 
sludges are listed only if the waste is not disposed in a subtitle C 
landfill, or put another way, the sludges would not be listed hazardous 
waste from the point of generation if they are disposed in a subtitle C 
landfill.
    As mentioned above, this alternative regulatory approach is based 
upon the presumption that disposal of untreated VCM-A sludge in a 
subtitle C landfill is protective. However, the Agency also is 
concerned that this waste can sometimes fail the TC for mercury (as 
discussed earlier, approximately 20 percent of the time based upon EPA 
and facility data). The existing treatment standards that otherwise 
would apply to this waste if it was characteristically hazardous for 
mercury include incineration (i.e., D009 high mercury/organic 
subcategory requires either incineration or mercury recovery), which 
may not be the most environmentally-sound manner in which to treat the 
waste prior to disposal. This is discussed in more detail in the LDR 
portion of today's rule (Section V). Because of this concern, this 
alternative option is structured in a fashion that allows the treatment 
standards being proposed today for K175 to apply in lieu of the 
existing standards for D009 for those VCM-A wastes that exhibit the 
characteristic for mercury.
    EPA requests comment on this proposed alternative listing approach. 
Also, EPA requests comment on whether it may be more appropriate to 
simply list the VCM-A wastewater treatment sludge unless it is sent to 
a subtitle C landfill, and propose alternative LDR treatment standards 
that would apply to VCM-A wastewater treatment sludges that exhibit the 
TC for mercury. We note that the Agency presently is revisiting the 
IMERC standard as part of a comprehensive re-evaluation of the LDR 
treatment standards for mercury-bearing wastes (see May 28, 1999 ANPRM; 
64 FR 28958). To the extent time allows, the Agency will consider 
relevant issues raised in the ANPRM in developing this final listing 
determination. However, because of the different schedules of these two 
actions and the consent decree deadline for finalizing today's proposed 
rule, we will not necessarily be able to consider any comments 
submitted to the ANPRM in finalizing today's rule.
    The Agency's proposed alternative listing description for VCM-A 
wastewater treatment sludges that will define this waste as hazardous 
only under certain conditions is as follows:

K175  Wastewater treatment sludges from the production of vinyl 
chloride monomer using mercuric chloride catalyst in an acetylene-
based process, unless: i) the sludges are disposed in a subtitle C 
landfill, and ii) the sludges do not fail the toxicity 
characteristic for mercury in 40 CFR 261.24, and iii) the generator 
maintains documentation demonstrating that the waste was disposed of 
in a subtitle C landfill or consigned to a transporter or disposal 
facility that provided a written commitment to dispose of the waste 
in a subtitle C landfill. Respondents in any action brought to 
enforce the requirements of subtitle C must, upon a showing by the 
government that the respondent managed wastewater treatment sludges 
from the production of vinyl chloride monomer using mercuric 
chloride catalyst in an acetylene-based process, demonstrate that 
they meet the terms of the exclusion set forth above. In doing so, 
they must provide appropriate documentation (e.g., contracts between 
the generator and the landfill owner/operator, invoices documenting 
delivery of waste to landfill, analytical results or other 
information showing the waste does not fail the toxicity 
characteristic for mercury, etc.) that the terms of the exclusion 
were met.

    The Agency requests comment on this alternative listing approach 
for VCM-A sludge. As already mentioned, EPA might choose this 
alternative regulatory approach if it decides direct disposal of 
untreated VCM-A sludge is protective without further treatment of this 
waste, due to the relative insolubility of mercuric sulfide, and the 
groundwater protections a lined landfill does provide.
d. What Is the Status of Landfill Leachate From Previously Disposed 
Wastes?
    Leachate derived from the treatment, storage, or disposal of listed 
hazardous wastes is classified as a hazardous waste by virtue of the 
``derived-from'' rule in 40 CFR 261.3(c)(2). The Agency has been clear 
in the past that hazardous waste listings apply to wastes disposed

[[Page 46515]]

of prior to the effective date of a listing, even if the landfill 
ceases disposal of the waste when the waste becomes hazardous. See 53 
FR 31147, August 17, 1988. We also have a well-established 
interpretation that listings likewise apply to leachate derived from 
the disposal of listed hazardous wastes, including leachate derived 
from wastes disposed before a listing effective date which meet the 
listing description. We are not reopening any of these issues with this 
proposed rulemaking.
    Of course, as set out in detail in the August 1988 notice, this 
does not mean that landfills holding wastes that are listed now as 
hazardous become subject to subtitle C regulation. However, previously 
disposed wastes now meeting a listing description, including residues 
such as leachate that are derived from such wastes, and that are 
managed actively do become subject to subtitle C regulation. See 53 FR 
31149, August 17, 1988. In many, indeed most circumstances, active 
management of leachate would be exempt from subtitle C regulation 
because the usual pattern of management is discharge either to POTWs 
via the sewer system, where leachate mixes with domestic sewage and is 
excluded from RCRA jurisdiction (see RCRA Section 1004(27) and 40 CFR 
261.4(a)(1)), or to navigable waters, also excluded from RCRA 
jurisdiction (see RCRA Section 1004(27) and 40 CFR 261.4(a)(2)). In 
addition, management of leachate in wastewater treatment tanks prior to 
discharge under the CWA is exempt from RCRA regulation (40 CFR 
264.1(g)(6)).
    If actively managed, landfill leachate and gas condensate derived 
from the newly-listed VCM-A waste proposed for listing in today's 
notice could be classified as K175. In such circumstances, we would be 
concerned about the potential disruption in current leachate management 
that could occur, and the possibility of redundant regulation. 
Recently, this issue was raised to the Agency in the context of the 
petroleum refinery waste listings. See 63 FR 42173, August 6, 1998. A 
commenter expressed concern that, because some of the commenter's non-
hazardous waste landfills received newly-listing petroleum wastes prior 
to the effective date of the listing decision, the leachate that is 
collected and managed from these landfills would be classified as 
hazardous. The commenter argued that this could lead to vastly 
increased treatment and disposal costs without necessarily any 
environmental benefit. After examining and seeking comment on this 
issue, we published a final rule that temporarily defers regulation of 
landfill leachate and gas condensate derived from certain listed 
petroleum refining wastes (K169-K172) that were disposed before, but 
not after, the new listings became effective, provided certain 
conditions are met. See 64 FR 6806, February 11, 1999.
    At the time this issue was brought to the Agency's attention in the 
context of the petroleum refinery waste listings, EPA's Office of Water 
had recently proposed national effluent limitations guidelines and 
pretreatment standards for wastewater discharges--most notably, 
leachate--from certain types of landfills. See 63 FR 6426, February 6, 
1998. In support of this proposal, EPA conducted a study of the volume 
and chemical composition of wastewaters generated by both subtitle C 
(hazardous waste) and subtitle D (non-hazardous waste) landfills, 
including treatment technologies and management practices currently in 
use. EPA proposed effluent limitations (for nine pollutants in the Non-
Hazardous Subcategory) for direct dischargers. See 63 FR 6463. Most 
pertinent to finalizing the temporary deferral for the petroleum 
refining wastes, EPA did not propose pretreatment standards for 
subtitle D landfill wastewaters sent to POTWs because the Agency's 
information indicated that such standards were not required.
    The conditions included in the temporary deferral published on 
February 11, 1999 are that the leachate is subject to regulation under 
the Clean Water Act, and the leachate cannot be stored in surface 
impoundments after February 13, 2001. See 40 CFR 261.4(b)(15). We 
believed that it was appropriate to temporarily defer the application 
of the new waste codes to such leachate in order to avoid disruption of 
ongoing leachate management activities while the Agency decides how to 
integrate the RCRA and CWA regulations consistent with RCRA Section 
1006(b)(1). We believe that the same fact pattern fully discussed in 
the February 11, 1999 rulemaking applies in this situation as well. As 
such, we would be concerned about forcing pretreatment of leachate even 
though pretreatment is neither required by the CWA, nor needed. 
Therefore, we are proposing to temporarily defer the regulation of 
landfill leachate and gas condensate derived from the VCM-A wastes, 
with the same conditions as described in 40 CFR 261.4(b)(15) for 
petroleum wastes. We believe the issue of whether disruptions can be 
minimized through integration of CWA and RCRA rules will be more 
amenable to resolution once the CWA rulemaking is completed.
e. What Specific Comments Is EPA Requesting on the Agency's Proposed 
Listing of VCM-A Wastewater Treatment Sludges?
    The Agency requests comments on the proposed listing of all VCM-A 
wastewater treatment sludges as well as the proposed conditional 
listing for this waste. In addition, the Agency requests comment on 
alternative management practices that may either be in use or may be 
appropriate for this wastestream, other than the disposal of these 
sludges in subtitle C landfills.
    We also request any available information on whether or not the 
VCM-A wastes were previously disposed in non-hazardous landfills. Even 
if we do not receive any information that previously disposed VCM-A 
wastes will result in generation of hazardous landfill leachate and gas 
condensate, we may still choose to promulgate the temporary deferral 
for landfill leachate and gas condensate from this waste. This is 
because someone may discover this problem later (after the effective 
date of the listing), so, by having a temporary deferral in place, it 
would be possible to avoid disruption of ongoing leachate management 
activities while we further examine this issue and await the CWA final 
rule.
4. Methyl Chloride Wastewater Treatment Sludges
a. How Is EPA Proposing To Regulate Methyl Chloride Wastewater 
Treatment Sludges?
    EPA is proposing not to list as hazardous sludges from the 
treatment of wastewaters generated from methyl chloride production 
processes. This wastestream does not meet the criteria set out at 40 
CFR 261.11(a)(3) for listing a waste as hazardous. It does not pose a 
substantial present or potential hazard to human health or the 
environment. The Agency identified limited risks to consumers of 
groundwater.
b. What Information Led EPA To Propose Not To List as Hazardous Methyl 
Chloride Wastewater Treatment Sludges?
    EPA identified only one facility that generates sludges from the 
treatment of wastewaters generated from the production of methyl 
chloride and does not currently manage the waste as hazardous. The 
results of the RCRA Section 3007 survey for the chlorinated aliphatics 
industry show that this facility generates less than 800 metric tons of 
this sludge each year and disposes of the sludge in an on-site landfill 
along with other wastes from

[[Page 46516]]

the facility. The landfill is lined and has a leachate collection 
system.
    In conducting the risk assessment for this sludge, EPA considered 
one management scenario, disposal in an on-site landfill. The Agency 
analyzed potential risks from methyl chloride wastewater treatment 
sludge by modeling a non-groundwater pathway. The Agency's analysis of 
potential risks due to volatile emissions from the landfill resulted in 
negligible risks to individuals in the surrounding area. The Agency 
also conducted a bounding (i.e., worst case) risk analysis to estimate 
potential risks to groundwater consumers. This analysis used the 
leachate concentration measured from a sample of the facility's methyl 
chloride wastewater treatment sludge, and assumed the direct ingestion 
of this leachate by an adult for a period of 58 years. This bounding 
analysis resulted in a risk of 5E-5 for one constituent, arsenic.
    The Agency views the arsenic risk results from the bounding 
analysis as marginal. Assuming a landfill DAF of only 5 (a reasonable 
assumption for an unlined landfill), the predicted risk becomes 1E-5, 
which is the typical level identified by EPA as posing sufficient risk 
to require the waste to be listed as hazardous(see 59 FR 66072, 66077). 
However, for this particular facility, EPA believes that the actual 
risk from this waste will be much lower than the risk level predicted 
by the bounding analysis given that the landfill currently used by the 
single facility generating this waste is lined with a 24-inch clay 
liner and has a leachate collection system.
    The Agency believes that the management practice of most concern 
(on-site landfill) was assessed, given that it is the only management 
practice used by the single facility generating the waste. Given that 
the landfill is located on site and has significant remaining capacity, 
the Agency sees no reason to assume that the facility will not continue 
to manage its wastewater treatment sludges from the production of 
methyl chloride in this manner.
    Based on an analysis of potential risks associated with current 
management practices, EPA is proposing not to list as hazardous 
wastewater treatment sludges from the production of methyl chloride. 
The Agency found no significant risks arising from the on-site landfill 
management scenario. The only possible concern arises from the marginal 
risk associated with arsenic, which falls at the risk level generally 
identified by EPA for listing a waste as hazardous, when assuming a DAF 
of 5. The Agency believes this assumption is reasonable for an unlined 
landfill, and likely results in an overestimate of risk for the 
management practice identified by EPA (i.e., an on-site landfill that 
operates with a clay liner and leachate collection at a single 
facility).
    The Agency requests comments on the approach taken to determine a 
no-list proposal for hazardous wastewater treatment sludges from methyl 
chloride manufacturing.
5. Allyl Chloride Wastewater Treatment Sludges
a. How Is EPA Proposing To Regulate Allyl Chloride Wastewater Treatment 
Sludges?
    EPA is proposing not to list as hazardous sludges generated from 
treating wastewaters associated with the manufacture of allyl chloride. 
This wastestream does not meet the criteria set out at 40 CFR 
261.11(a)(3) for listing a waste as hazardous. It does not pose a 
substantial present or potential threat to human health or the 
environment. The Agency has identified no risks of concern associated 
with the current management of the waste.
b. What Information Led EPA To Propose To Not List as Hazardous Allyl 
Chloride Wastewater Treatment Sludges?
    Wastewater treatment sludges from allyl chloride production are 
generated at a single facility. The sludges are generated from the 
facility's centralized wastewater treatment system. This wastewater 
treatment system is a non-dedicated system in that wastewaters from the 
facility's multiple production processes are discharged to the single 
system for combined treatment. Wastewaters from the production of allyl 
chloride contribute less than two percent to the system's total sludge 
loading. According to the RCRA Section 3007 survey response, the sludge 
generated from the facility's wastewater treatment system is 
incinerated on site in a non-hazardous waste incinerator.
    During the investigations undertaken in support of the listing 
determinations, EPA collected one sample of this sludge. Two duplicate 
TCLP analyses were performed using the sample collected. The sample 
also was analyzed for total concentrations of dioxins and furans. The 
TCLP analyses indicated the presence of no TCLP constituents above 
regulatory levels. The total arsenic concentration in the waste was 
11.7 mg/kg, while the total dioxin (TEQ/TCDD) concentration was 11.79 
ng/kg.
    The Agency does not anticipate any significant risk from the 
incineration of allyl chloride wastewater treatment sludge in a non-
hazardous waste incinerator, since both the total arsenic level 
47 and the total dioxin level 48 detected in the 
sludge are well within the range of background levels of those 
constituents in soils.
---------------------------------------------------------------------------

    \47\ Alkhatib, Eid, and O'Connor, Timothy, ``Background Levels 
of Priority Pollutant Metals in Soil, American Environmental 
Laboratory, Vol. 10, No. 3, April, 1998.
    Hunter, Philip M., ``Air-Force Wide Background Concentrations of 
Inorganics Occurring in Ground Water and Soil,'' Proceedings from 
the Fourteenth Annual Waste Testing and Quality Assurance Symposium, 
Pp. 73-77, 1998.
    Welch, Alan H., Lico, Michael S., and Hughes, Jennifer L., 
``Arsenic in Ground Water of the Western United States,'' Ground 
Water, Vol. 26, No. 3, May/June, 1988.
    \48\ See Table 4-4 of ``Risk Assessment Technical Background 
Document for the Chlorinated Aliphatics Listing Determination,'' 
EPA, June 25, 1999.
---------------------------------------------------------------------------

    The Agency did not conduct an analysis of risk associated with 
other management practices, based upon the fact the waste is generated 
by a single facility and currently is not managed in a manner other 
than non-hazardous waste incineration.
    Given that wastewater treatment sludges from allyl chloride 
production are generated by a single facility, that the sludge 
generated is the product of a facility-wide non-dedicated (i.e., not 
process-specific) wastewater treatment system, and that no significant 
risks are posed by the waste attributable to the allyl chloride 
production process, the Agency is proposing not to list this waste as 
hazardous.
    The Agency requests comments on the approach taken to determine to 
propose not to list as hazardous wastewater treatment sludges from 
allyl chloride manufacturing.

F. Constituents Proposed for Addition to Appendix VIII to 40 CFR Part 
261

    Two of the constituents of concern that are present in the 
chlorinated aliphatic wastewaters (K173) and the EDC/VCM wastewater 
treatment sludges (K174) proposed to be listed as hazardous waste do 
not currently appear on the list of hazardous constituents at 40 CFR 
part 261, appendix VIII. Therefore, EPA is proposing to add these two 
constituents, octachlorodibenzo-p-dioxin (OCDD) and 
octachlorodibenzofuran (OCDF), to appendix VIII. OCDD and OCDF are 
members of the large family of polychlorinated dioxins and furans. 
Certain of these compounds, most notably, 2,3,7,8 TCDD, have been shown 
to be extremely toxic.
    As discussed in section III.D of today's proposed rule, the 
Agency's risk assessment found significant risks associated with the 
presence of dioxins

[[Page 46517]]

in both chlorinated aliphatic wastewaters and EDC/VCM wastewater 
treatment sludges. In the case of our analysis of risk for both 
categories of waste, the dioxin/furan concentrations were measured on a 
TCDD TEQ basis. As previously discussed in today's proposed rule, TCDD 
TEQ concentrations are calculated by multiplying each 2,3,7,8 congener 
by the appropriate TEF, and then summing the resultant concentrations 
to come up with a TCDD TEQ value. OCDD and OCDF are part of this 
calculation.
    Available data indicate that 2,3,7,8-substituted congeners of 
chlorinated dibenzo-p-dioxin and dibenzofurans have toxic effects 
similar to 2,3,7,8,-TCDD. Data available from in vivo and in vitro 
studies reveal a strong structure-activity relationship, in which the 
2,3,7,8-substituted congeners are much more biologically active than 
other congeners. Both OCDD and OCDF are 2,3,7,8-substituted congeners. 
Available data also show that the relative responses of different PCDDs 
and PCDFs are generally consistent across a variety of toxicity end 
points. 49 In regard to OCDD specifically, test animals 
exhibited initial signs of ``dioxin toxicity'' in a subchronic study of 
mice exposed to OCDD at low levels.50
---------------------------------------------------------------------------

    \49\ U.S. Environmental Protection Agency. 1989 Update to the 
Interim Procedures for Estimating Risks Associated with Exposures to 
Mixtures of Chlorinated Dibenzo-p-Dioxins and -Dibenzofurans (CDDs 
and CDFs). Washington, D.C.: Risk Assessment Forum, March, 1989. 
EPA/625/3-89/016.
    \50\ Couture, L.A., M.R. Elwell, and L.S. Birnbaum. ``Dioxin-
like Effects Observed in Male Rats Following Exposure to 
Octachlorodibenzo-p-dioxin (OCDD) during a 13-week Study.'' 
Toxicology and Applied Pharmacology, Vol. 93, Pp 31-46, 1988.
---------------------------------------------------------------------------

    EPA also points out that the oral slope factors for OCDD and OCDF 
(calculated by multiplying the cancer slope factor for 2,3,7,8 TCDD by 
the TEFs for OCDD and OCDF, which are both 0.0001 51) are 
relatively high (15/(mg/kg)/day) compared to the oral slope factor of 
other hazardous constituents currently listed in appendix VIII to 40 
CFR 261 (e.g., arsenic has an oral slope factor of 1.5/(mg/kg)/day).
---------------------------------------------------------------------------

    \51\ Using the toxicity equivalency factor (TEF) developed by 
the World Health Organization, see section III.D.1.g.ii of today's 
proposed rule for discussion of TEFs.
---------------------------------------------------------------------------

    Therefore, we have concluded that, based upon sufficient evidence 
to show that OCDD and OCDF are hazardous constituents and based upon 
the fact that OCDD and OCDF are the only congeners that make up TCDD 
TEQ that are not currently listed in appendix VIII, OCDD and OCDF 
should be added to appendix VIII of 40 CFR part 261. The Agency 
requests comment on its proposal to add OCDD and OCDF to the list of 
hazardous constituents in appendix VIII to 40 CFR 261.

IV. Economic Analysis

A. What Is the Purpose of the Economic Analysis?

    The primary purpose of the economic analysis presented in the 
``Economic Background Document,'' is to estimate potential industry 
compliance costs associated with this listing proposal. Secondary 
purposes are to provide descriptive information about the economic 
(industry) sectors affected, and about the economic activities 
involving chlorinated aliphatic hydrocarbon chemicals (CAHCs). The 
Economics, Methods, and Risk Assessment Division (EMRAD) of EPA's 
Office of Solid Waste (OSW) conducted the economic analysis. The 
``Economic Background Document'' is available to the public from the 
RCRA docket (refer to the introduction to this preamble for 
instructions on how to obtain a copy). The findings of the economic 
study are summarized in this section of the preamble. References to 
statements below pertaining to facts, data, assumptions and other types 
of information, are identified in the document.

B. How May the Public Participate in the Economic Analysis?

    The USEPA encourages the public to provide comments and suggestions 
about the design, accuracy, representativeness and completeness of the 
``Economic Background Document.''
    In preparing the Economic Background Document, the EPA preferred to 
the maximum extent possible, to use publicly-available rather than 
confidential business information (CBI) as information and data 
sources, to facilitate transparency for public review and comment. 
However, some information was designated by survey companies as CBI 
when collected in the 1992 and 1997 Section 3007 surveys administered 
by EPA (described elsewhere in this preamble). Consequently, the 
background data and information available to the EPA during development 
of this listing proposal also consisted of CBI information. In order to 
minimize reliance on CBI data, and to exhaust available public 
information sources, EPA consulted many other databases as supplements 
and substitutes to the RCRA Section 3007 survey, in conducting the 
economic study.
    EPA particularly requests written comments from the public on the 
information elements listed below pertaining to the economic analysis 
presented in the ``Economic Background Document:''

    1. Study Design: Suggestions for modifications and improvements 
to the scope, methodology, and organization of the Economic 
Background Document (e.g., 30-year cost annualization ``period-of-
analysis'' applied).
    2. Facility Universe: Correct number and locations of CAHC 
manufacturing and any other types of facilities and entities 
potentially affected by the RCRA listing proposal.
    3. Affected Wastes: Correct average annual quantities, types and 
industrial source (origin) of potentially affected CAHC 
manufacturing wastes.
    4. Industry Profile: Characterization of the role, functions and 
industrial organization associated with the production and use of 
CAHCs in the US economy.
    5. Baseline Waste Management: Characterization of baseline 
(current) waste management practices associated with CAHC 
manufacturing wastes (both onsite and offsite management practices), 
including the types and relative waste quantities managed, types of 
waste management units, costs of waste management ($/ton basis), 
waste commingling and segregation, etc. In particular, there is 
uncertainty in the Section 3007 survey data, about the exact number 
and sizes of wastewater management tanks used by CAHC manufacturing 
facilities.
    6. Compliance Waste Management: Adaptation of CAHC manufacturing 
facilities to the RCRA listing proposal if finalized, such as 
changes in CAHC manufacturing plant & equipment, facility layout, 
production processes and methods, business arrangements, CAHC 
product mixes, etc. What are possible operating consequences to 
waste management facilities for meeting K175 waste pH and sulfide 
landfill restrictions?
    7. Facility Process Modifications: Identification and dollar 
value of lump-sum capital investment costs required (per industrial 
operating unit or facility).
    8. Unit Costs: Overall representativeness of unit costs applied 
to the universe of CAHC manufacturing facilities for industrial 
waste management, involving both non-hazardous and hazardous waste 
handling.
    9. Impact Benchmarks: The appropriateness of the alternative 
company financial benchmarks (e.g., annual sales revenues, annual 
profits, capital expenditures, short-term credit) presented in this 
study, and of other benchmarks not presented, for purpose of 
providing measurement references relative to assessing the dollar 
magnitude of the estimated industry compliance costs.
    10. Supporting Data: The data applied in the economic study are 
from sources published over a number of years, and for some key data 
elements, are more than five years old (e.g., during preparation of 
this study, the US Bureau of Census' 1997 Survey of Manufacturers 
data reports were not yet available).
    11. Other Considerations: Any other comments pertaining to other 
aspects of the economic study, or to topics which have been omitted 
or are outside the scope of the

[[Page 46518]]

study, if relevant to assessing the economic impact of the listing 
proposal.

C. How Are Chlorinated Aliphatic Chemicals Used in the Economy?

    Chlorinated aliphatic hydrocarbon chemicals (CAHCs) entered into 
commerce in the US in the early 1920s, and as of 1994, approximately 38 
billion pounds of 50 different commercially significant CAHCs were 
manufactured by 23 chemical plants (facilities) in the United States. 
The US production of CAHCs has grown an average annual rate of 4.4 
percent over the last 30 years.
    CAHCs are a group of organic chemicals--most of which are colorless 
liquids at room temperature--primarily used as intermediate feedstocks 
for the production of polyvinyl chloride (PVC) plastics; CAHCs are also 
used directly in liquid form as various types of solvents, as 
intermediates for the production of other types of chemicals, and in 
assorted other commercial use categories. As of 1996, three CAHCs--
ethylene dichloride, vinyl chloride, methyl chloride--were on the list 
of top-50 chemicals produced in the United States.

D. Where Are CAHCs Manufactured in the United States?

    In conjunction with contacts of industry representatives, EPA 
identified an initial subset of industrial facilities relevant to the 
scope of the listing proposal, according to both the (a) types of 
chemical products manufactured, as well as the (b) types of industrial 
wastestreams generated from the chemical manufacturing processes. EPA 
identified a total of 28 facilities in the 1992 Section 3007 industry 
survey, and a total of 26 facilities in the 1997 follow-up survey, as a 
result of two facility closures in the interim period. Three of the 26 
facilities were discovered to be either ``de minimus'' producers of 
CAHCs, or double-counted in the survey, which resulted in a final 
subset of 23 relevant CAHC manufacturing facilities.
    The relevant subset of 23 CAHC manufacturing facilities surveyed in 
USEPA-OSW's 1997 survey are located in eight states (Kansas, Kentucky, 
Louisiana, Maryland, Michigan, New York, Tennessee, and Texas), and 
employ an average of over 700 employees per facility. Total employment 
for all 23 facilities is about 19,000 employees, and the total 
employment associated with the 16 parent companies which own these 23 
facilities is much larger, estimated at 526,700 employees.

E. Have CAHCs Been Produced Historically in Other Locations in the 
United States?

    In addition to current databases, there are assorted documents 
which contain historical information about the CAHC production industry 
in the United States. Historically, CAHCs have been manufactured and/or 
used as feedstocks and intermediates in chemical production plants in 
at least 15 states in the US. The historical data on the number and 
location of CAHC production facilities serves to illustrate the dynamic 
business activity in this industry sector. As late as 1975, CAHCs were 
produced in the US by 32 companies in 58 plant locations.

F. What Are the Estimated Potential Industry Costs of This Listing?

    There are two associated categories of potential compliance costs 
for CAHC manufacturers under this listing proposal: (a) process 
wastewater listing costs, and (b) wastewater treatment sludge listing 
costs. These costs are incremental to current waste management costs in 
this industry, in the sense that all CAHC manufacturing facilities are 
currently regulated under RCRA (i.e., as chlorinated aliphatic 
manufacturers via the existing RCRA F025 and F026 wastecodes, among 
others), and some facilities currently manage most or all of their CAHC 
manufacturing wastes as hazardous. Consequently, this listing proposal 
will not have a full incremental impact on these facilities, and the 
marginal impact on their existing operations in relation to current 
RCRA compliance and hazardous waste handling practices may be less than 
it otherwise would be if these companies and facilities did not have 
experience with baseline RCRA waste management practices.
    As summarized in Table IV-1 below, EPA estimates the total industry 
compliance cost--excluding paperwork burden as separately estimated in 
the Information Collection Request--associated with the two wastestream 
components of the listing proposal (i.e., sludges and wastewaters), at 
$2.355 million in average annual cost, for annual waste management in 
conformance with the terms of the listing proposal. This total cost 
consists of an estimated $1.320 million in initial capital expenditures 
(30-year annualized equivalent of $0.046 million), and an estimated 
$2.309 million in recurring annual costs.

Table IV-1.--Summary of Estimated Industry Compliance Costs for the RCRA
 Listing Proposal; Wastewater Treatment Sludges and Wastewaters. Average
                  Annual Equivalent Total Industry Cost
------------------------------------------------------------------------
                 Type of CAHC facility
                potentially affected by       Initial        Recurring
    Item       the proposed RCRA listing   capital costs    annual O&M
                        options            ($ lump-sum)   costs ($/year)
------------------------------------------------------------------------
A.            SLUDGE LISTING ESTIMATED
               COSTS:
A1              Non-landfilled EDC/VCM                $0      $1,333,000
               sludge.
A2              VCM-A process w/mercury                0         209,000
               catalyst.
             -----------------------------------------------------------
                  Subtotal sludge costs.               0       1,542,000
B.            WASTEWATER LISTING
               ESTIMATED COSTS:
B1              Tank fixed roof + valve.       1,084,600          81,600
B2              Tank roof vent + carbon          150,900         591,200
               control.
B3              Tank ``Subpart CC''                    0          23,700
               ancillary costs*.
B4              Initial waste testing             84,500               0
               for dioxins.
B5              Annual waste retesting                 0          70,400
               for dioxins.
             -----------------------------------------------------------
                  Subtotal wastewater          1,320,000         766,900
               costs.
                                         -------------------------------
C.            SLUDGE + WASTEWATER COSTS        1,320,000       2,309,000
               (column totals).
                                         ===============================

[[Page 46519]]

 
                  Total annualized        ..............       2,355,000
               equivalent cost.
------------------------------------------------------------------------

V. Proposed Treatment Standards Under RCRA's Land Disposal 
Restrictions

A. What Are EPA's Land Disposal Restrictions (LDRs)?

    The RCRA statute requires EPA to establish treatment standards for 
all wastes destined for the land disposal. These are the so called 
``land disposal restrictions'' or LDRs. For any hazardous waste 
identified or listed after November 8, 1984, EPA must promulgate these 
LDR treatment standards within six months of the date of identification 
or final listing (RCRA Section 3004(g)(4), 42 U.S.C. 6924(g)(4)). RCRA 
also requires EPA to set as these treatment standards ``* * * levels or 
methods of treatment, if any, which substantially diminish the toxicity 
of the waste or substantially reduce the likelihood of migration of 
hazardous constituents from the waste so that short-term and long-term 
threats to human health and the environment are minimized.'' (RCRA 
Section 3004(m)(1), 42 U.S.C. 6924(m)(1)).
    Wastes that meet treatment standards established by EPA may be land 
disposed. Wastes that do not meet these standards are prohibited from 
land disposal (except in so-called no-migration units). Each waste 
proposed for listing as hazardous in this rule will be subject to all 
the land disposal restrictions on the same day their respective listing 
becomes effective.

B. How Does EPA Develop LDR Treatment Standards?

    To establish LDR treatment standards, EPA first identifies the best 
demonstrated available technology (BDAT) for the hazardous constituents 
present in the hazardous waste, and then determines what constituent 
concentrations can be achieved by the technology or technologies 
identified as BDAT.
    EPA typically has established treatment standards based on 
performance data from the treatment of the waste at issue, if such data 
are available, and also from the treatment of wastes with similar 
chemical and physical characteristics or similar concentrations of 
hazardous constituents. Treatment standards typically cover both 
wastewater and nonwastewater waste forms on a constituent-specific 
basis. The constituents selected for regulation under the LDR program 
are not necessarily limited to those present in a proposed listing, but 
also may include those constituents or parameters that will ensure that 
treatment technologies are operated properly. For listed waste EPA 
identifies these as ``regulated constituents'' and they appear 
individually in the Table at 40 CFR 268.40, along with their respective 
treatment standards.
    EPA may develop and promulgate either technology-specific treatment 
standards or numerical treatment standards. Should EPA elect to use 
technology-specific standards, all wastes that meet the listing 
designations would have to be treated by the technology or technologies 
specified before disposal. These technologies are also identified in 
the Table at Sec. 268.40 and are further described in Sec. 268.42. 
Should EPA elect to use numerical treatment standards, the Agency 
allows the use of any technology (other than impermissible dilution) to 
comply with the treatment standards.
    After developing the LDR treatment standards, we must also 
determine if significant treatment capacity is available to treat the 
expected volumes of wastes. If so, the LDR treatment standards become 
effective essentially at the same time a listing does. If not, EPA may 
grant up to a two-year national capacity variance (NCV) during which 
time the LDR treatment standards are not effective.
    For a more detailed overview of the Agency's approach for 
developing treatment standards for hazardous wastes, see the final rule 
on solvents and dioxins (51 FR 40572, November 7, 1986) and section 
III.A.1 of the preamble to the final rule that set land disposal 
restrictions for the ``Third Third'' wastes (55 FR 22535, June 1, 
1990). EPA also has explained its BDAT procedures in ``Best 
Demonstrated Available Technology (BDAT) Background Document for 
Quality Assurance/Quality Control Procedures and Methodology (EPA/OSW, 
October 23, 1991)'' . This document is available in the docket 
supporting this rulemaking.

C. What Kind of Treatment Standards Are Proposed?

    EPA has gathered data on waste characteristics and current 
management practices for wastes proposed in this action as part of the 
administrative record for this rule, and has evaluated these data to 
develop specific treatment standards. An examination of the 
constituents that are the basis of the proposed listings shows that the 
Agency has previously developed numerical treatment standards for most 
of the constituents of concern. After reviewing the available 
characterization data and the available information on waste management 
practices for these wastes proposed for listing, EPA has determined 
that it is technically feasible and justified to apply existing 
universal treatment standards (UTS) to the regulated hazardous 
constituents of concern in the wastes proposed to be listed as K173 and 
K174. For K175, EPA is proposing a metals recovery requirement as the 
treatment standard, namely roasting and retorting. Although the mercury 
in K175 would be recovered, other treatment residuals will exist. For 
these residuals, we are proposing that existing UTS will be applicable.
    Available information also shows that these wastes and the 
treatment residuals can be managed in existing treatment and 
reclamation units that routinely manage similar or as-difficult-to-
treat hazardous wastes that currently are prohibited from land 
disposal. The BDAT background document provides further information on 
EPA's rationale for applying UTS to these wastes and the treatment 
standard of metals recovery to K175. Also see LDR Phase II final rule, 
59 FR 47982, September 19, 1994, for a further discussion of UTS.
    For proposed K173 and K174, EPA is proposing to regulate specific 
constituents from each of these hazardous wastes. A list of the 
proposed regulated hazardous constituents and

[[Page 46520]]

the proposed treatment limits can be found in the following preamble 
section and in the proposed regulatory Table 268.40--Treatment 
Standards for Hazardous Wastes. If EPA makes a final decision to list 
the identified wastes, these constituents and standards would apply.
    EPA has provided in the BDAT background document a review of 
thermal and nonthermal technologies that can be used to meet the 
proposed numerical concentration limits for proposed K173 and K174, 
assuming the design and operation of these technologies are optimized. 
Since EPA is proposing numerical concentration limits, the use of other 
technologies capable of achieving the proposed treatment standards is 
allowed, except for those treatment or reclamation practices 
constituting land disposal or impermissible dilution (see 40 CFR 
268.3). As noted above, EPA is proposing a specified technology-
specific treatment standard for K175. K175 waste would therefore have 
to be treated by the required technology and the residues thereof or 
subsequent residues would have to meet numerical UTS concentration 
limits. 52
---------------------------------------------------------------------------

    \52\ There are two exceptions. Where the treatment technology is 
not appropriate to the waste, regulations provide a petition process 
whereby the generator or treatment facility may petition the 
Administrator for a variance. See 40 CFR 268.44. In addition, 
persons can petition the Administrator for an alternate treatment 
method by showing that the alternate method can achieve a measure of 
performance equivalent to the method specified by rule.
---------------------------------------------------------------------------

D. Other LDR-Related Provisions

    We propose that the provisions in 40 CFR 268.45 would also be 
applicable for the treatment and disposal of hazardous debris 
contaminated with proposed K173, K174, and K175. Hazardous debris 
treated in accordance with the provisions of 40 CFR 268.45 may be 
allowed for land disposal in a hazardous waste disposal facility. As a 
result, debris contaminated with proposed K173, K174, and K175 would be 
required to be treated prior to land disposal, using specific 
technologies from one or more of the following families of debris 
treatment technologies: extraction, destruction, or immobilization. 
Residuals generated from the treatment of debris contaminated with 
proposed K173, K174, or K175 will have to meet the applicable UTS 
limits proposed today. See 57 FR 37277, August 18, 1992, for additional 
information on the applicability, scope, and content of the hazardous 
debris provisions.
    We note that, when the listings proposed today become final, the 
alternative soil treatment standards in 40 CFR 268.49 would be 
available for any soils contaminated with the newly listed wastes. 
Soils that must meet LDRs before land disposal may be treated to the 
levels in the alternative soil treatment standards as long as the soils 
will not be used in a manner constituting disposal. Even though EPA is 
proposing a method of treatment for K175, the waste contains an 
analyzable hazardous constituent. Consequently, the alternative 
treatment standards may apply and specify that the analyzable 
constituent must be at specified levels for soil contaminated with the 
waste to be disposed. See 268.49(c)(3)(B), promulgated at 63 FR 28751. 
Such soils can only be land disposed (here, recycled by being placed on 
the land) if they first meet UTS. See 63 FR 28609-28610 (May 26, 1988).
    A facility is not required to use these alternative soil treatment 
standards and may elect to comply with the traditional LDR treatment 
standards for process waste. The choice of whether to do so potentially 
impacts how many constituents must meet LDR treatment standards. If a 
site chooses to meet the alternative soil treatment standards and their 
soils are contaminated with a listed waste, then they are required to 
treat both the regulated hazardous constituents specified in 268.40 and 
also any underlying hazardous constituents. Potential underlying 
hazardous constituents are listed in the UTS Table at 268.48. However, 
if the traditional treatment standards are applied to a soil 
contaminated with a listed waste, then only the regulated constituents 
specified in 268.40 must meet the treatment standards. For further 
discussion of the alternative soil treatment standards, please refer to 
the final Phase IV LDR rule (63 FR 28556, 28609, May 26, 1998) and the 
subsequent clarification notice (64 FR 25410-25411, May 11, 1999).
    Lastly, because land disposal also includes placement in injection 
wells (40 CFR 268.2(c)) application of the land disposal restrictions 
to proposed K173, K174, and K175 requires the modification of injection 
well requirements found in 40 CFR 148. We propose that K167 and K168 be 
prohibited from underground injection. See 40 CFR 148. Therefore, 
wastes proposed to be listed as K173, K174, and K175 may not be 
underground injected unless they have been treated in compliance with 
the LDR treatment standards or a no migration petition for these wastes 
has been approved.

E. What Standards Is EPA Proposing for K173?

    EPA is proposing to apply existing Universal Treatment Standards to 
proposed K173 wastes. We have examined the constituents that comprise 
the basis of the proposed listing and identified the presence of those 
other constituents near on in excess of current numerical universal 
treatment standards. Wastes that exceed these levels require treatment 
of the constituents to diminish the toxicity of the waste and to reduce 
the likelihood of migration of the hazardous constituents. Based on 
this examination, we propose treatment standards for bis(2-
chloroethyl)ether, chloroform, pentachlorophenol, phenol, 2,4,6-
trichlorophenol, chromium(total), and nickel in addition to 
tetrachlorodibenzodioxins, pentachlorodibenzodioxins, 
hexachlorodibenzodioxins, heptachlorodibenzodioxins, 
tetrachlorodibenzofurans, pentachlorodibenzofurans, 
hexachlorodibenzofurans, heptachlorodibenzofurans, OCDD, and OCDF in 
proposed K173.
    Existing LDR standards for the wastes that contain chlorinated 
dibenzo-para-dioxins and dibenzofurans are expressed in terms of all 
tetrachlorodibenzo-p-dioxins, pentachlorodibenzo-p-dioxins, 
hexachlorodibenzo-p-dioxins, tetrachlorodibenzofurans, 
pentadibenzofurans, hexachlorodibenzofurans, OCDD, and OCDF. Today's 
notice proposes treatment standards for five additional dioxin/furan 
congeners, namely 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin, 
1,2,3,4,6,7,8-heptachlorodibenzofuran, 1,2,3,5,7,8,9-
heptachlorodibenzofuran, OCDD, and OCDF. We are doing so because these 
constituents are present at concentrations that present significant 
risks should proposed hazardous waste K173 be mismanaged.
    For proposed K173 nonwastewaters, we propose that the LDRs for the 
three new congeners (1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin, 
1,2,3,4,6,7,8-heptachlorodibenzofuran, 1,2,3,5,7,8,9-
heptachlorodibenzofuran, OCDD, and OCDF) be set at the quantitation 
limits of method 8280A. These quantitation limits are achievable 
routinely, and being 3 to 4 times the detection limit of residues from 
combustion, they are a reasonable approximation of 2.8 times the method 
detection limit normally used to develop treatment standards from 
detection limit data to account for

[[Page 46521]]

potential treatment variability. 53 Since method 8280A was 
first developed, the more sensitive high-resolution mass spectrometry 
method 8290 has been developed. Method 8290 may achieve detection 
limits orders of magnitude more sensitive than Method 8280A. However, 
we lack actual treatment performance data for these wastes using method 
8290. Further, because of the trace levels of dioxins/furans that 
method 8290 is capable of detecting, we can not presume that combustion 
would achieve the much lower non-detectable levels of method 8290. 
Therefore, we are proposing to base treatment standards for the five 
congeners cited above on the more widely available method 8280A. We 
specifically invite data to be submitted on the levels that can be 
achieved using method 8290.
---------------------------------------------------------------------------

    \53\ See Best Demonstrated Available Technology (BDAT) 
Background Document for Quality Assurance/Quality Control Procedures 
and Methodology, EPA, October 23,1991.
---------------------------------------------------------------------------

    From past trial burns, we have confidence that incineration has 
been fully demonstrated for treating dioxin-containing wastes. As 
explained in 1989 solvents and dioxin rule, Method 8280A failed to 
detect chlorinated dibenzo-p-dioxins and dibenzofurans in residues from 
trial burns. This has led the Agency to conclude that the residual 
levels of chlorinated dibenzo-p-dioxins and dibenzofurans that remain 
after treatment would be well below the levels proposed. See 51 FR 
1734, January 14, 1986. Therefore, for the three new congeners, we are 
proposing standards based on these data showing that high temperature 
thermal treatment achieved destruction of these constituents to levels 
below the stated quantitation limits of method 8280A.
    For proposed K173 wastewaters, we propose that the UTS treatment 
level of 0.000035 mg/L for pentachlorodibenzofuran be transferred to 
1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin, 1,2,3,4,6,7,8-
heptachlorodibenzofuran, and 1,2,3,5,7,8,9-heptachlorodibenzofuran. 
Pentachlorodibenzofuran is a structural homologue of these constituents 
with similar physical properties, which allows us to assume similar 
treatment efficiencies. Similarly, we propose that the UTS treatment 
level of 0.000063 mg/L for tetrachlorodibenzofuran be transferred to 
OCDD and OCDF. For all other dioxin/furan congeners, we propose to 
transfer the current, corresponding universal treatment standards.
    For the specific numerical standards proposed to be applicable to 
proposed K173, see the proposed amendments to 40 CFR 268.40 at the end 
of this preamble. We request comment on the proposed treatment 
standards for proposed K173.

F. What Standards Is EPA Proposing for K174?

    EPA is proposing to apply existing Universal Treatment Standards 
(UTS) to these wastes. We have examined the constituents that comprise 
the basis of the proposed listing and identified the presence of those 
other constituents near on in excess of current numerical universal 
treatment standards. Waste that exceed these levels require treatment 
of the constituents to diminish the toxicity of the waste and to reduce 
the likelihood of migration of the hazardous constituents. Based on 
this examination, we propose that wastes proposed to be listed as K174 
be treated for arsenic, tetrachlorodibenzo-p-dioxins, 
pentachlorodibenzo-p-dioxins, hexachlorodibenzo-p-dioxins, 
heptachlorodibenzo-p-dioxins, tetrachlorodibenzofurans, 
pentachlorodibenzofurans, hexachlorodibenzofurans, 
heptachlorodibenzofurans, OCDD, and OCDF. We are proposing to apply the 
new numerical standards for the five new congeners (one 
heptachlorodibenzo-p-dioxin, two heptachlorodibenzofurans, OCDD, and 
OCDF), discussed in the previous section, to proposed hazardous waste 
K174 because these constituents are also present in proposed K174 
wastes at significant concentrations that would present risks should 
the wastes be mismanaged.
    We request comment on the proposed treatment standards for wastes 
proposed to be listed as K174.

G. What Standards Is EPA Proposing for K175?

    Proposed hazardous waste K175 is generated from the treatment of 
catalyst change-out wastewaters from the chlorination of acetylene on a 
mercuric chloride catalyst. As with the above wastes, we have examined 
the constituents that comprise the basis of the proposed listing and 
identified the presence of mercury as the only constituent that would 
require treatment to diminish the toxicity of the waste and to reduce 
the likelihood of migration. Proposed K175 contains in excess of 260 
mg/kg mercury and is greater than one percent in organic constituents. 
This type of waste profile is similar to wastes that are currently 
deemed to be characteristically hazardous under the D009 waste code. 
Therefore, in assessing what type of LDR treatment standards are 
warranted for proposed K175, we look first to the D009 treatment 
standards.
    Current regulations for similar D009 wastes require either 
retorting or roasting (RMERC) or incineration in units operated in 
accordance with the technical operation requirements of 40 CFR Part 
264, Subpart O and Part 265, Subpart O (IMERC ). However, current 
regulations do not require combustion units to capture and recover 
mercury from the combustion gases produced. If all the mercury 
contained in these wastes were combusted without capture and removal, 
the result would be over one metric ton per year of mercury emissions. 
Under the upcoming revisions to the hazardous waste combustion 
regulations, it is not clear that facilities are going to choose to 
employ air pollution control devices (capture and removal devices) to 
comply with mercury emission limits. They might instead simply choose 
to reduce their feed rate, which will not reduce the total amount of 
mercury emitted over the long term. Given this uncertainty about future 
compliance strategies by the hazardous waste combustion industry, we 
are proposing that mercury recovery by retorting or roasting (RMERC) be 
the required treatment technology for this waste. RMERC requires 
processing in devices subject to mercury emission controls resulting in 
mercury capture and removal, and also subject to emission standards 
such as the National Emissions Standard for Hazardous Air Pollutants 
(NESHAP) for mercury. See 40 CFR 268.42. For residues of the RMERC 
process, we propose to adopt the current standard of 0.20 mg/L TCLP 
mercury.
    The Agency has contacted a treatment vendor of RMERC technology who 
indicated that treatment of the subject wastes may be difficult, but is 
possible.54 We therefore request treatment performance data 
regarding the use of retorting for these waste.
---------------------------------------------------------------------------

    \54\ Personal communication with John Boyle, Bethlehem Apparatus 
Co., Inc.
---------------------------------------------------------------------------

    Absent definitive treatment data, we have considered whether an 
alternative treatment standard to retorting might be feasible to 
propose for comment. One alternative is to establish a numerical 
concentration limit. Under current regulations, mercury wastes that are 
stabilized are subject to a standard of 0.025 mg/L TCLP mercury. This 
differs from the initial option of retorting in two key respects. 
First, use of specific treatment technology would not be required and, 
second, the treated waste or waste residuals would be subject to a 
numerical standard about one order of

[[Page 46522]]

magnitude more stringent--0.2 mg/L for retorting residuals under the 
first option vs. 0.025 mg/L for all treatment residuals under this 
second option.
    Without the assurance of treatment that a requirement for retorting 
would provide, the tighter standard of 0.025 mg/L TCLP is appropriate 
to propose as a potential treatment standard. This standard would apply 
to all treatment residuals included in the listing description for 
proposed hazardous waste K175, regardless of the type of treatment 
used. In practice, this standard would involve the immobilization of 
the mercury in the waste before land disposal. If regulations were to 
be promulgated in this form, the waste could be land disposed if a 
standard of 0.025 mg/L TCLP mercury was achieved using any technology 
other than impermissible dilution.
    Calculated solubilities of mercury sulfide (metacinnabar) as a 
function of pH have revealed that above pH 6.0 the presence of sulfide 
complexes results in significantly increased solubility.55 
Preliminary results from constant pH leaching measurements of the 
subject waste, as part of an on-going study, have shown similar 
results.56 At pH 6.0 the waste tested leached 0.0058 mg/L. 
However, at pH 10, 1.63 mg/L mercury was solubilized. Current landfill 
disposal site conditions for this waste are reported to be pH 9.48-
9.57.57 Under these conditions, mercury in the waste would 
be expected to be mobilized especially if excess sulfides were present. 
Therefore, controlled treatment and disposal conditions are warranted 
to avoid mobilization of the mercury in the waste, which could pose a 
significant threat to human health and the environment. To insure 
operational stability of the treatment process and proper long-term 
disposal, EPA proposes two conditions as part of the LDR treatment 
standards. First, the waste residue generated, if in mercuric sulfide 
form, must itself be pH 6.0 or below. We therefore propose that 
mercuric sulfide residues of this waste be treated to attain a pH of 
less than or equal to 6.0. Second, if proposed K175 wastes are to be 
co-disposed in a landfill with other wastes, co-disposal will be 
restricted to wastes with similar pH (i.e., not greater than 6.0). To 
comply with these requirements disposal facilities would be required to 
certify and maintain operating records available for inspection of 
codisposed wastes to demonstrate compliance.
---------------------------------------------------------------------------

    \55\ 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.
    \56\ Paul Bishop, Renee A. Rauche, Linda A. Rieser, Markram T. 
Suidan, and Jain Zhang; ``Stabilization and Testing of Mercury 
Containing Wastes,'' Draft, Department of Civil and Environmental 
Engineering, University of Cincinnati, March 31, 1999. Please note 
that this is a draft EPA document not yet peer reviewed. Also, data 
within the report is still undergoing QA/QC review, and the text, 
data, and conclusions in the report may change before the document 
is finalized.
    \57\ May 14, 1999, landfill parameters, e-mail from Mitch Hahn, 
Waste Management.
---------------------------------------------------------------------------

    Currently, the wastes proposed to be listed as K175 are landfilled 
after treatment has converted mercuric chloride in wastewaters to 
mercuric sulfide. We believe significant opportunities exist for source 
reduction and waste minimization to reduce or eliminate the generation 
of this waste. For example, the need to hydroblast spent mercuric 
chloride catalyst from reactors could be eliminated by internal 
segmentation of the reactor bed that would allow the segments to be 
sent intact for mercury recovery. Thus, generation of the waste could 
be eliminated or significantly reduced. Beyond modifications to the 
physical plant, the treatment of the wash waters could be modified to 
incorporate addition of caustic and organic phase separation. This 
would result in a mercuric oxide sludge more amenable to recovery by 
retorting prior to sulfide treatment of the resulting brine. As a 
result of such changes, a smaller volume of mercuric sulfide sludge 
with reduced organic content would be generated, as would a larger 
volume of a more easily recoverable mercuric oxide sludge.
    We request treatment performance data on the treatment standards 
proposed and on other alternative treatment technologies that would 
meet the statutory criteria for all LDR standards ``minimizing threats 
to human health and the environment by reductions in the toxicity or 
mobility of the wastes through the treatment process. We also request 
comment on the feasibility of source reduction and waste minimization 
alternatives described above.

H. What Other Land Disposal Restrictions Aspects Are There to the 
Proposal?

    EPA is proposing to add the numerical standards derived for the 
1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin, 1,2,3,4,6,7,8-
heptachlorodibenzofuran, 1,2,3,4,7,8,9-heptachlorodibenzofuran, 
1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin (OCDD) and 1,2,3,4,6,7,8,9-
octachlorodibenzofuran (OCDF) to the Table of Universal Treatment 
Standards (UTS) at 40 CFR 268.48. These constituents have been shown to 
represent significant risks to human health or the environment in the 
risk assessment accompanying this proposal, and their presence in other 
wastes should be mitigated to avoid similar risks. If promulgated, all 
characteristic wastes which have these constituents as underlying 
hazardous constituents above the UTS thus will require treatment of 
those constituents before land disposal.
    Furthermore, we are proposing that the constituents 1,2,3,4,6,7,8-
heptachlorodibenzo-p-dioxin; 1,2,3,4,6,7,8-heptachlorodibenzofuran, 
1,2,3,4,7,8,9-heptachlorodibenzofuran; OCDD; and OCDF be added to the 
list of regulated constituents in hazardous waste F039 multisource 
leachate. F039 applies to multiple listed hazardous waste landfill 
leachates in leu of the original waste codes, and F039 wastes are 
subject to all numerical treatment standards applicable to all listed 
wastes. To maintain regulatory consistency with this regulatory 
architecture and the implementation benefits of having one waste code 
for multisource leachate, the treatment standards for F039 are updated 
each time a new LDR standard is developed for listed wastes. As a 
result, if today's proposal is ultimately promulgated, all leachate 
(liquids that have percolated through land disposed wastes) resulting 
from the disposal of more than one restricted hazardous waste will have 
to meet UTS for all hazardous constituents above the UTS.

I. Is There Treatment Capacity for the Proposed Wastes?

1. What Is a Capacity Determination?
    EPA must determine whether adequate alternative treatment capacity 
exists nationally to manage the wastes subject to LDR treatment 
standards. RCRA section 3004 (h)(2). Thus, LDRs are effective when the 
new listings are effective as well (typically 6 months after the new 
listings are published in the Federal Register), unless EPA grants a 
national capacity variance from the otherwise-applicable date and 
establishes a different date (not to exceed two years beyond the 
statutory deadline) based on ``* * * the earliest date on which 
adequate alternative treatment, recovery, or disposal capacity which 
protects human health and the environment will be available'' (RCRA 
section 3004(h)(2), 42 U.S.C. 6924(h)(2)).
    Our capacity analysis methodology focuses on the amount of waste 
currently disposed on the land, which will require alternative or 
additional treatment as a result of the LDRs. The quantity of wastes 
that is not disposed

[[Page 46523]]

on the land, such as discharges regulated under NPDES, discharges to a 
POTW, or treatment in a RCRA-exempt tank, is not included in the 
quantities requiring additional treatment as a result of the LDRs. 
Also, land-disposed wastes that do not require alternative or 
additional treatment are excluded from the required capacity estimates 
(i.e., those that currently are treated to meet the LDR treatment 
standards). Land-disposed wastes requiring alternative or additional 
treatment or recovery capacity that is available on site or within the 
same company also are excluded from the required commercial capacity 
estimates. The resulting estimates of required commercial capacity then 
are compared to estimates of available commercial capacity. If adequate 
commercial capacity exists, the waste is restricted from further land 
disposal. If protective alternative capacity does not exist, EPA has 
the authority to grant a national capacity variance.
    In making the estimates described above, the volume of waste 
requiring treatment depends on the current waste management practices 
employed by the waste generators before this proposed regulation is 
promulgated and becomes effective. Data on waste management practices 
for these wastes were collected during the development of this proposed 
rule. However, we realize that as the regulatory process proceeds, 
generators of these wastes may decide to minimize or recycle their 
wastes or otherwise alter their management practices. Thus, we will 
monitor changes and update data on current management practices as 
these changes will affect the volume of wastes ultimately requiring 
commercial treatment or recovery capacity.
    The commercial hazardous waste treatment industry can change 
rapidly. For example, national commercial treatment capacity changes as 
new facilities come on line or old facilities go off line, and as new 
units and new technologies are added at existing facilities. The 
available capacity at commercial facilities also changes as facilities 
change their commercial status (e.g., changing from a fully commercial 
to a limited commercial or ``captive''--company owned--facility). Thus, 
EPA also continues to update and monitor changes in available 
commercial treatment capacity.
    We request data on the annual generation volumes and 
characteristics of wastes affected by this proposed rule, including 
proposed hazardous wastes K173, K174, and K175 in wastewater and 
nonwastewater forms, soil or debris contaminated with these wastes, 
residuals generated from the treatment or recycling of these wastes, 
and the current and planned management practices for the wastes, waste 
mixtures, and treatment residuals.
    We also request data on the current treatment or recovery capacity 
capable of treating these wastes, facility and unit permit status 
related to treatment of the proposed wastes and any plans that 
facilities may have to expand or reduce existing capacity, or construct 
new capacity. Of particular interest to us are waste characteristics, 
such as pH, total organic carbon content, constituent concentrations, 
and physical forms that may limit the availability of certain treatment 
technologies. Also of interest are any analytical difficulties 
associated with identifying and monitoring the regulated constituents 
in these wastes.
2. What are the Capacity Analysis Results?
    This preamble only provides a brief summary of the capacity 
analysis performed to support this proposed regulation. For additional 
and more detailed information, please refer to the ``Background 
Document for Capacity Analysis for Land Disposal Restrictions: Newly 
Identified Chlorinated Aliphatics Process Wastes (Proposed Rule), July 
1999.''
    For this capacity analysis, we examined data on waste 
characteristics and management practices gathered for the purpose of 
the chlorinated aliphatics hazardous waste listing determination. The 
source for these data is primarily the 1992 RCRA Section 3007 survey 
and the follow-up survey specific to these wastes conducted in 1997 
(see the docket for this proposed regulation for more information on 
these survey instruments).
    The available data sources indicate that proposed K173 wastes are 
predominantly wastewaters, but may exhibit total suspended solids 
content greater than 1 percent, such that they would be classified as 
nonwastewaters with respect to the LDR requirements (40 CFR 268.2). EPA 
has found that most facilities generating proposed K173 manage these 
wastes in tank-based systems prior to a permitted discharge to a 
surface water or POTW. The non-CBI portions of the Section 3007 survey 
responses, as well as other publicly available information, indicate 
that certain facilities manage proposed K173 using underground 
injection with existing approved no-migration determinations. Proposed 
K173 managed by land disposal units may require alternative treatment 
if onsite management to meet the LDR standards or alternative onsite 
management is not available. EPA expects that sufficient offsite 
treatment capacity is available to manage proposed K173 generated by 
these facilities. Specifically, EPA estimates that approximately 37 
million tons per year of offsite wastewater treatment capacity are 
available, which is well above the quantity of proposed K173 generated 
by these facilities. Therefore, sufficient commercial capacity exists 
to manage proposed K173 from these facilities should the need for 
treatment of proposed K173 wastes arise.
    As discussed in this section earlier, the LDR treatment standards 
become effective essentially at the same time a listing does unless EPA 
grants a national capacity variance because of a lack of available 
treatment capacity (see RCRA section 3004(h)(2)). Also, RCRA allows 
generators to apply for an extension to the LDR effective date on a 
case-by-case basis for specific wastes generated at a specific facility 
for which there is not adequate capacity (RCRA section 3004(h)(3)). For 
those facilities managing proposed K173 wastes, they may choose to meet 
treatment standards by onsite or offsite treatment, submit a modified 
no-migration petition to include newly listed wastes if necessary, or 
transport their wastes to a commercial Class I hazardous disposal well 
facility.
    Based on EPA's information, the facilities managing proposed K173 
wastes by underground injection have existing approved no-migration 
determinations. If an injection well has received a no-migration 
determination, it can inject a newly prohibited waste if the waste is 
similar to wastes included in the initial no-migration petition (63 FR 
28626, May 26, 1998). EPA has information showing that the facilities 
already manage these newly-proposed K173 wastes in their underground 
injection wells. Further, EPA's sampling and analysis results for 
wastewater from one of the facilities shows that none of the 
constituents being proposed for inclusion in 40 CFR 268.40 for proposed 
K173 (i.e., numerical treatment standards) were present at 
concentrations greater than the proposed numerical treatment standards. 
This suggests that for this facility, the newly-proposed treatment 
standards for proposed K173 might already be met.
    Based on the available data presented above, EPA is not proposing a 
national capacity variance for surface-disposed or underground-injected 
proposed K173 wastes. However, EPA recognizes that there are 
uncertainties in the available data such that a facility may require 
extra time (beyond the effective date) to

[[Page 46524]]

comply with the new listing and land disposal restrictions 
requirements, if finalized. For example, EPA realizes that proposed 
K173 can be variable in composition and not always exhibit 
concentrations below the proposed numerical treatment standards. Also, 
any facility with an approved no-migration determination without the 
waste already incorporated in the determination may need to submit a 
modified petition (40 CFR Part 148.20 (f)). Potentially, the 
modification process for the existing no-migration petition, as well as 
the permit modification itself, may be time-consuming. There are 
potential logistical difficulties associated with accessing available 
treatment capacity for wastewater, as well. For example, if a facility 
generates high volumes of proposed K173 and cannot manage the waste 
onsite in a manner compliant with the LDR standards, they may need to 
make considerable logistical adjustments such as repiping, retooling, 
and development of transportation networks at the plant in order to 
ship the wastewater offsite for treatment or disposal. Additionally, 
although commercial treatment or disposal capacity is available, the 
logistics of transporting high volumes of wastewater may be 
problematic, particularly if existing piping, onsite storage, or 
loading are not in place. Should these difficulties arise such that 
both onsite and offsite treatment and disposal are not available for 
facilities currently using underground injection, EPA will consider all 
available data and information provided during the public comment 
period and revise its capacity analysis accordingly in making the final 
capacity determination.
    For K174 wastes, the available data sources indicate that there is 
no quantity of the wastewater form of K174 that will require 
alternative commercial treatment. There is adequate wastewater 
treatment capacity available should the need for treatment of the 
wastewater form of K174 arise. From the available data sources, 
required alternative treatment capacity for K174 nonwastewater may be 
as low as 1,900 tons per year if most generators meet the proposed 
requirements for contingent management listing. If the generators do 
not manage K174 nonwastewater according to contingent management for 
the listing designation, the waste generated must meet LDR standards 
before land disposal, and the total quantity requiring treatment may be 
up to 106,000 tons per year. As described in the BDAT section above, we 
are proposing that numerical treatment standards be applied to K174 
nonwastewaters. These standards were derived by estimating the 
concentration level following use of combustion technologies. We 
estimate that the commercially available sludge and solid combustion 
capacity is at least 300,000 tons per year and therefore sufficient to 
treat the proposed K174 hazardous waste that would require treatment. 
Therefore, EPA is proposing not to grant a capacity variance for K174 
nonwastewaters or wastewaters.
    For wastes proposed to be listed as K175, the available data 
sources indicate that there is no quantity of the wastewater form of 
proposed K175 that will require alternative commercial treatment. There 
is adequate wastewater treatment capacity available should the need for 
treatment of the wastewater form of K175 arise. For nonwastewater form 
of proposed K175, EPA estimates that up to 130 tons per year may 
require alternative commercial treatment. As described in the BDAT 
section above, two options are proposed as the treatment standard. In 
one option, the treatment standard was proposed as a technology 
standard (RMERC), with residues meeting a concentration level. We have 
identified at least one facility that operates commercially and that 
potentially can be used for the treatment of wastes proposed to be 
listed as K175; there are other treaters which conduct RMERC and the 
details are discussed in the Capacity Analysis Background Document. We 
recognize that treatment residuals from these wastes may require 
additional treatment capacity (e.g., stabilization of the ash following 
combustion of the wastes) to achieve the UTS for any metal constituents 
that may be present in the residuals. We estimate that there is several 
million tons per year of commercial stabilization capacity available. 
In the second option for nonwastewater form of proposed K175 described 
in the BDAT section above, the treatment standard would be a numerical 
standard followed by certain landfill restrictions. EPA expects that 
commercial treaters can customize their treatment process to immobilize 
the waste, attain a pH of less than 6.0, and meet the treatment 
standard. Therefore, sufficient commercial treatment capacity exists 
for this proposed K175 hazardous waste. EPA is proposing to not grant a 
national capacity variance from LDR treatment standards for 
nonwastewater or wastewater forms of proposed K175.
    Also, the ultimate volumes of wastes estimated to require 
alternative or additional commercial treatment may change if the final 
listing determinations change; should this occur, we will revise the 
capacity analysis accordingly.
    For soil and debris contaminated with these wastes, EPA believes 
that the vast majority of contaminated soil and debris contaminated 
with these wastes will be managed on site and therefore will not 
require substantial commercial treatment capacity. Therefore, we are 
not proposing to grant a national capacity variance for hazardous soil 
and debris contaminated with the newly listed wastes covered under this 
proposal. Based on the 1992 RCRA 3007 Survey questionnaire responses 
and 1997 updated responses, there are no data showing mixed radioactive 
wastes associated with the proposed listings. We are not proposing to 
grant a national capacity variance for mixed radioactive wastes (i.e., 
radioactive wastes mixed with proposed K173, K174, or K175) or soil and 
debris contaminated with these mixed radioactive wastes. As discussed 
in this section earlier, EPA also is not proposing to grant a national 
capacity variance for proposed K173, K174, or K175 wastes being 
surface-disposed or underground injected.
    EPA requests comments on current and future management practices 
and the volumes managed for these wastes. Also, we request comments on 
other commercially-available thermal and non-thermal treatment or 
recovery capacity that would achieve proposed LDR treatment standards 
for these wastes and on chemical and physical constraints of treatment 
technologies for the wastes. Specifically, EPA requests comments on its 
proposal to not grant a capacity variance for proposed K173 waste. EPA 
solicits comments on physical and chemical characteristics of proposed 
K173 wastes, any treatment problems before disposing of proposed K173, 
the time and necessary procedures required for permit modifications for 
proposed K173 generators or commercial treatment or disposal 
facilities, required changes for operating practices, and any specific 
difficulties in making treatment capacity unavailable that would 
warrant a variance. For nonwastewater form of proposed K175, we solicit 
any information regarding the availability of RMERC for treating the 
wastes, and regarding chemical and physical constraints to meet 
numerical standards and pH restriction for this waste.

IV. Compliance Dates

A. Notification

    Under RCRA Section 3010 any person generating, transporting, or 
managing a hazardous waste must notify EPA (or an authorized State) of 
its activities.

[[Page 46525]]

Section 3010(a) allows EPA to waive, under certain circumstances, the 
notification requirements under Section 3010 of RCRA. EPA is proposing 
to waive the notification requirement as unnecessary for persons 
already identified within the hazardous waste management universe 
(i.e., persons who have an EPA identification number under 40 CFR 
262.12). EPA is not proposing to waive the notification requirement for 
waste handlers who have neither notified the Agency that they may 
manage hazardous wastes nor received an EPA identification number. Such 
individuals will have to provide notification under Section 3010. Any 
person who generates, transports, treats, stores, or disposes of these 
wastes and has not previously received an EPA identification number, 
must do so within 90 days of the effective date of the final rule.

B. Interim Status and Permitted Facilities

    Today's proposed rule is being proposed under the authorities 
granted to EPA under HSWA. Because HSWA requirements are applicable in 
authorized States at the same time as in unauthorized States, EPA will 
regulate the newly identified wastes listed under HSWA until States are 
authorized to regulate these wastes. Thus, once this regulation becomes 
effective as a final rule, EPA will apply Federal regulations to these 
wastes and to their management in both authorized and unauthorized 
States.

VII. State Authority

A. Applicability of Rule in Authorized States

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

B. Effect on State Authorizations

    Because this proposal (with the exception of the actions proposed 
under CERCLA authority) will be promulgated pursuant to the HSWA, a 
State submitting a program modification is able to apply to receive 
either interim or final authorization under Section 3006(g)(2) or 
3006(b), respectively, on the basis of requirements that are 
substantially equivalent or equivalent to EPA's requirements. The 
procedures and schedule for State program modifications under Section 
3006(b) are described in 40 CFR 271.21. It should be noted that all 
HSWA interim authorizations are currently scheduled to expire on 
January 1, 2003 (see 57 FR 60129, February 18, 1992).
    Section 271.21(e)(2) of EPA's State authorization regulations (40 
CFR Part 271) requires that states with final authorization modify 
their programs to reflect Federal program changes and submit the 
modifications to EPA for approval. Once EPA approves the modification, 
the State requirements become RCRA subtitle C requirements. Because 
this rule would be promulgated pursuant to HSWA, if the proposal is 
adopted as a final rule, Table 1 at 40 CFR 271.1 will be amended 
accordingly. If finalized, EPA will implement this rule in all States, 
including authorized States, until the States modify their authorized 
programs to reflect this rule.

VIII. Designation of Chlorinated Aliphatic Wastes (Proposed K173, 
K174 and K175) Under the Comprehensive Environmental Response, 
Compensation, and Liability Act (CERCLA)

A. What Is the Relationship Between RCRA and CERCLA?

    CERCLA defines the term ``hazardous substance'' to include RCRA 
hazardous wastes. When EPA adds a hazardous waste under RCRA, the 
Agency also will add the waste to its list of CERCLA hazardous 
substances. EPA establishes a reportable quantity or RQ for each CERCLA 
hazardous substance. EPA provides a list of the CERCLA hazardous 
substances along with their RQs in Table 302.4 at 40 CFR 302.4. If you 
are the person in charge of a vessel or facility that releases a CERCLA 
hazardous substance in an amount that equals or exceeds its RQ, then 
you must report that release to the National Response Center (NRC). You 
also may have to notify State and local authorities.

B. Is EPA Proposing To Add Chlorinated Aliphatic Wastes to CERCLA?

    Yes. Today, EPA is proposing to add chlorinated aliphatic wastes 
(Proposed K173, K174 and K175) to the list of CERCLA hazardous 
substances. As discussed below, EPA also proposes to adjust the RQs for 
these wastes.

C. How Does EPA Determine Reportable Quantities?

    Under CERCLA, all new hazardous substances automatically have a 
statutory one-pound RQ. EPA adjusts the RQ of a newly added hazardous 
substance based on an evaluation of its intrinsic physical, chemical, 
and toxic properties. These intrinsic properties--called ``primary 
criteria''--are aquatic toxicity, mammalian toxicity (oral, dermal, and 
inhalation), ignitability, reactivity, chronic toxicity, and potential 
carcinogenicity. EPA evaluates the data for a hazardous substance for 
each primary criterion. To adjust the RQs, EPA ranks each criterion on 
a scale that corresponds to an RQ value of 1, 10, 100, 1,000, or 5,000 
pounds. For each criterion, EPA establishes a tentative RQ. A hazardous 
substance may receive several tentative RQ values based on its 
particular intrinsic properties. The lowest of the tentative RQs 
becomes the ``primary criteria RQ'' for that substance.
    After the primary criteria RQs are assigned, EPA further evaluates 
substances for their susceptibility to certain degradative processes. 
These are secondary adjustment criteria. The

[[Page 46526]]

natural degradative processes are biodegradation, hydrolysis, and 
photolysis (BHP). If a hazardous substance, when released into the 
environment, degrades rapidly to a less hazardous form by one or more 
of the BHP processes, EPA generally raises its RQ (as determined by the 
primary RQ adjustment criteria) by one level. Conversely, if a 
hazardous substance degrades to a more hazardous product after its 
release, EPA assigns an RQ to the original substance equal to the RQ 
for the more hazardous substance.
    The standard methodology used to adjust the RQs for RCRA hazardous 
waste streams differs from the methodology applied to individual 
hazardous substances. The procedure for assigning RQs to RCRA waste 
streams is based on the results of an analysis of the hazardous 
constituents of the waste streams. The constituents of each RCRA 
hazardous waste stream are identified in 40 CFR Part 261, Appendix VII. 
EPA first determines an RQ for each hazardous constituent within the 
waste stream using the methodology described above. The lowest RQ value 
of these constituents becomes the adjusted RQ for the waste stream. 
When there are hazardous constituents of a RCRA waste stream that are 
not CERCLA hazardous substances, the Agency develops an RQ, called a 
``reference RQ,'' for these constituents in order to assign an 
appropriate RQ to the waste stream (see 48 FR 23565, May 25, 1983). In 
other words, the Agency derives the RQ for waste streams based on the 
lowest RQ of all of the hazardous constituents, regardless of whether 
they are CERCLA hazardous substances.

D. When Do I Need To Report a Release of Proposed K173, K174 or K175 
Under CERCLA?

    Today, EPA is proposing to adjust statutory RQs for the proposed 
K173, K174 or K175 waste streams to one pound based on their hazardous 
constituents. EPA is proposing to adjust the RQ at one pound for the 
proposed K173 and K174 waste streams based on their hazardous 
constituents, chlorinated dibenzo-p-dioxins (CDDs) and chlorinated 
dibenzofurans (CDFs). EPA is proposing to adjust the RQ at one pound 
for the proposed K175 waste stream based on its hazardous constituent, 
mercury. However, in determining when to report a release of proposed 
K173, K174 or K175, EPA is proposing to allow you to apply the mixture 
rule, codified in 40 CFR 302.6, using the maximum observed 
concentrations of the hazardous constituents within the respective 
waste streams.
    The mixture rule provides that ``discharges of mixtures and 
solutions are subject to RQ regulations only where a component 
hazardous substance of the mixture or solution is discharged in a 
quantity equal to or greater than its RQ'' (44 FR 50767, August 29, 
1979). Therefore, if the concentration of a hazardous constituent is 
known, the amount of release needed to reach its RQ can be calculated. 
By using the maximum observed concentration that EPA is proposing 
today, you may apply the mixture rule, even if you don't know the 
concentration of constituents released. That is, if you are the person 
in charge, you must immediately report the release as soon as you know 
that you have released proposed K173, K174 or K175 in an amount that 
will reach the RQ for the waste stream. This approach is reasonable and 
conservative because the sampling data presented in the Listing 
Background Document accurately identify the maximum observed 
concentrations of the hazardous constituents in the chlorinated 
aliphatics waste streams. Table VIII-1 below identifies the hazardous 
constituents for each waste stream, their maximum observed 
concentrations in parts per million (ppm), and their constituents' RQs 
or reference RQs.

 Table VIII-1.--Maximum Observed Concentration and Corresponding RQ for
 Hazardous Constituents That Are Basis for Listing Proposed K173, K174,
                                and K175
------------------------------------------------------------------------
                                                     Max.
       Waste               Constituent           Concentration   RQ (lb)
                                                 (ppm (mg/kg))
------------------------------------------------------------------------
K173..............  2,3,7,8-TCDD.............       0.000000017        1
                    1,2,3,7,8-PeCDD..........       0.00000015         1
                    1,2,3,4,7,8-HxCDD........       0.00000012         1
                    1,2,3,6,7,8-HxCDD........       0.00000091         1
                    1,2,3,7,8,9-HxCDD........       0.00000092         1
                    1,2,3,4,6,7,8-HpCDD......       0.000044           1
                    OCDD.....................       0.00022            1
                    2,3,7,8-TCDF.............       0.00000045         1
                    1,2,3,7,8-PeCDF..........       0.0000012          1
                    2,3,4,7,8-PeCDF..........       0.0000015          1
                    1,2,3,4,7,8-HxCDF........       0.000042           1
                    1,2,3,6,7,8-HxCDF........       0.000045           1
                    1,2,3,7,8,9-HxCDF........       0.000014           1
                    2,3,4,6,7,8-HxCDF........       0.000027           1
                    1,2,3,4,6,7,8-HpCDF......       0.0013             1
                    1,2,3,4,7,8,9-HpCDF......       0.00017            1
                    OCDF.....................       0.006              1
                    Chloroform...............       7.1               10
K174..............  2,3,7,8-TCDD.............       0.000039           1
                    1,2,3,7,8-PeCDD..........       0.0000108          1
                    1,2,3,4,7,8-HxCDD........       0.000024           1
                    11,2,3,6,7,8-HxCDD.......       0.000083           1
                    1,2,3,7,8,9-HxCDD........       0.000062           1
                    1,2,3,4,6,7,8-HpCDD......       0.00123            1
                    OCDD.....................       0.0129             1
                    2,3,7,8-TCDF.............       0.000145           1
                    1,2,3,7,8-PeCDF..........       0.0000777          1
                    2,3,4,7,8-PeCDF..........       0.000127           1
                    1,2,3,4,7,8-HxCDF........       0.001425           1
                    1,2,3,6,7,8-HxCDF........       0.000281           1

[[Page 46527]]

 
                    1,2,3,7,8,9-HxCDF........       0.00014            1
                    2,3,4,6,7,8-HxCDF........       0.000648           1
                    1,2,3,4,6,7,8-HpCDF......       0.0207             1
                    1,2,3,4,7,8,9-HpCDF......       0.0135             1
                    OCDF.....................       0.212              1
  K175              Mercury..................    9200                  1
------------------------------------------------------------------------

    For example, if proposed K173 is released from your facility and 
you do not know the actual concentrations of its constituents, you may 
assume that the concentrations are those identified in Table VIII-1. 
Thus, applying the mixture rule to the assumed maximum concentrations 
indicated in the table, you would have to release 1,408,450 pounds to 
reach the RQ for this waste (based on the maximum observed 
concentration of chloroform). If proposed K174 waste is released from 
your facility and you do not know the actual concentrations of its 
constituents, you may apply the mixture rule to the assumed maximum 
concentrations indicated in the table. You would have to release 
4,716,981 pounds of proposed K174 to reach the RQ for this waste (based 
on the maximum observed concentration of OCDF). If proposed K175 is 
released from your facility and you do not know the actual 
concentration of mercury, you may assume that the concentration is 9200 
ppm. Applying the mixture rule, you would have to release 108.7 pounds 
of this waste to reach the RQ.

E. What if I Know the Concentration of the Constituents in My Waste?

    If you know the concentration levels of all the hazardous 
constituents in a particular chlorinated aliphatic waste, you may apply 
the mixture rule (see 40 CFR 302.6(b)) to the actual concentrations. 
You would need to report a release of either waste when an RQ or more 
of any of their respective hazardous constituents is released.

F. How Did EPA Determine the RQs for Proposed K173, K174 and K175 and 
Their Hazardous Constituents?

    The hazardous constituents identified as the basis for listing the 
proposed K173 and K174 waste streams include chlorinated dibenzo-p-
dioxins (CDDs) and chlorinated dibenzofurans (CDFs). Previously, EPA 
had established an adjusted RQ of one pound for 2,3,7,8-TCDD (see 54 FR 
33426). EPA has not established adjusted RQs for the other CDD and CDF 
congeners. However, EPA recognizes that a number of these congeners 
exhibit dioxin-like toxicity and has established ``reference RQs'' of 
one pound for these congeners to support the development of the 
adjusted RQs for the proposed K173 and K174 waste streams.
    The adjusted RQ for 2,3,7,8-TCDD was established as one pound based 
on potential carcinogenicity, considering the weight of evidence that 
this substance is carcinogenic, and considering its estimated 
carcinogenic potency. To establish reference RQs for the other CDD and 
CDF congeners in the waste stream, EPA applied the toxicity equivalency 
factors (TEFs) established for dioxin-like compounds to the potency 
factor used as the basis for the adjusted RQ for 2,3,7,8-TCDD. Of the 
210 CDD and CDF congeners, only those with chlorine substitutions in, 
at least, the 2, 3, 7, and 8 positions (a total of 17 CDD and CDF 
congeners) are considered to have dioxin-like toxicity. Applying the 
TEFs established for these 17 congeners to the potency factor 
established for 2,3,7,8-TCDD indicates that all of the congeners fit 
into RQ Potency Group 1 with a corresponding reference RQ of one 
pound.58 Therefore, because each of the hazardous 
constituents has an RQ or reference RQ of one pound, EPA is proposing 
to establish an adjusted RQ of one pound for the proposed K173 and K174 
waste streams.
---------------------------------------------------------------------------

    \58\  For an explanation of how potency factors are calculated 
and potency groups and RQs are established, see the Technical 
Background Document to Support Rulemaking Pursuant to CERCLA Section 
102, Volume 3, July 27, 1989. This document can be viewed by calling 
the EPA Superfund Docket Center, 703-603-8917, and requesting 
document number 102 RQ 273C.
---------------------------------------------------------------------------

    The hazardous constituent identified as the basis for proposing to 
list the K175 waste stream is mercury. Previously, EPA had established 
an adjusted RQ of one pound for mercury (see 50 FR 13456, April 4, 
1985). Because the hazardous constituent used as the basis for listing 
the K175 waste stream has an RQ of one pound, EPA is proposing to 
establish an adjusted RQ of one pound for this waste.

G. How Do I Report a Release?

    To report a release of proposed K173, K174 or K175 (or any other 
CERCLA hazardous substance) that equals or exceeds its RQ, you must 
immediately notify the National Response Center (NRC) as soon as you 
have knowledge of that release. The toll-free telephone number of the 
NRC is 1-800-424-8802; in the Washington, DC, metropolitan area, the 
number is (202) 267-2675.
    You also may have to notify State and local authorities. The 
Emergency Planning and Community Right-to-Know Act (EPCRA) requires 
that owners and operators of certain facilities report releases of 
CERCLA hazardous substances and EPCRA extremely hazardous substances 
(see list in 40 CFR Part 355, Appendix A) to State and local 
authorities. After the release of an RQ or more of any of those 
substances, you must report immediately to the community emergency 
coordinator of the local emergency planning committee for any area 
likely to be affected by the release, and to the State emergency 
response commission of any State likely to be affected by the release.

H. What Is the Statutory Authority for This Program?

    Section 101(14) of CERCLA defines the term hazardous substance by 
referring to substances listed under several other environmental 
statutes, as well as those substances that EPA designates as hazardous 
under CERCLA Section 102(a). In particular, CERCLA Section 101(14)(C) 
defines the term hazardous substance to include ``any hazardous waste 
having the characteristics identified under or listed pursuant to 
Section 3001 of the Solid Waste Disposal Act.'' CERCLA Section 102(a) 
gives EPA authority to establish RQs for CERCLA hazardous substances. 
CERCLA Section 103(a) requires any person in charge of a vessel or 
facility that releases a CERCLA hazardous substance in an amount equal 
to or

[[Page 46528]]

greater than its RQ to report the release immediately to the federal 
government. EPCRA Section 304 requires owners or operators of certain 
facilities to report releases of CERCLA hazardous substances and EPCRA 
extremely hazardous substances to State and local authorities.

I. How Can I Influence EPA's Thinking on Regulating Proposed K173, K174 
and K175 Under CERCLA?

    In developing this proposal, EPA tried to address the concerns of 
all our stakeholders. Your comments will help us to improve this 
proposal. We invite you to provide your views on this proposal and how 
it may affect you. We also are interested in receiving any comments 
that you have on the information provided in Table VIII-1, including 
the hazardous constituents identified for proposed K173, K174 and K175 
and the maximum observed concentrations for each constituent.

IX. Administrative Assessments

A. Executive Order 12866

    Under Executive Order 12866 (September 30, 1993), EPA must 
determine whether a regulatory action is ``significant'' and, 
therefore, subject to OMB review and the other provisions of the 
Executive Order. A significant regulatory action is defined by 
Executive Order 12866 as one that may:

    (1) Have an annual effect on the economy of $100 million or more 
or adversely affect in a material way the economy, a sector of the 
economy, productivity, competition, jobs, the environment, public 
health or safety, or State, local, or tribal governments or 
communities;
    (2) Create a serious inconsistency or otherwise interfere with 
an action taken or planned by another agency;
    (3) Materially alter the budgetary impact of entitlements, 
grants, user fees, or loan programs or rights and obligations or 
recipients thereof; or
    (4) Raise novel legal or policy issues arising out of legal 
mandates, the President's priorities, or the principles set forth in 
Executive Order 12866.

Pursuant to the terms of Executive Order 12866, EPA has determined that 
this rule is a ``significant regulatory action'' because of point four 
(4) above: The rule raises two novel legal or policy issues arising out 
of legal mandates, the President's priorities, or the principles set 
forth in this Executive Order. Today's proposed rule, which includes 
proposed alternative listing approaches for two wastestreams deviates 
from the Agency's standard or historic listing approach in the 
following two ways:

     Targeted wastestream listing: Historically, the 
Agency's listing program captured entire quantities of targeted 
wastestream posing unacceptable risks to human health and the 
environment. Today's proposed listing approach for two wastestreams 
(i.e., EDC/VCM wastewater treatment sludges and one alternative 
option for VCM-A wastewater treatment sludges) proposes listing as 
hazardous only those quantities of the waste that are managed in a 
manner that reflects unacceptable risks.
     Wastewater treatment units: In addition, today's action 
proposes to change a long-standing Agency policy of exempting from 
RCRA regulation the management of hazardous wastes in wastewater 
treatment units regulated under Sec. 402 or Sec. 307(b) of the Clean 
Water Act. To address the risks associated with the wastewaters 
proposed to be listed as hazardous under today's action, the Agency 
believes that it is necessary to regulate these management units 
when used to manage chlorinate aliphatic wastewaters, to ensure 
against hazardous air emissions from this wastestream. (In section 
III.E.1.a.vi. of today's preamble, EPA is requesting comment on this 
approach.)

Due to the Agency's decision to propose a deviation from our historical 
hazardous waste listing approach and to change our long-standing policy 
regarding the regulation of wastewater treatment units, the Agency is 
deeming today's action to be ``significant'' and is submitting these 
proposed policy changes to OMB for review. Changes made to the Agency's 
proposed actions in response to OMB suggestions or recommendations are 
documented in the public record.
    Although today's proposed rule is not ``economically significant,'' 
the Agency prepared an ``Economic Background Document'' in support of 
today's rule. The Agency's economic assessment addresses, among other 
factors, industry compliance costs, industry financial impacts, and 
potential for small entity impacts. A summary of findings from our 
economic assessment is presented in Section IV. The complete Economic 
Background Document is available for public review from the RCRA 
docket, according to instructions provided in the introduction to this 
preamble.

B. Regulatory Flexibility Act

    Pursuant to the 1980 Regulatory Flexibility Act (RFA) (5 U.S.C. 601 
et seq., as amended by the Small Business Regulatory Enforcement 
Fairness Act (SBREFA) of 1996), whenever an agency is required to 
publish a notice of rulemaking for any proposed or final rule, it must 
prepare and make available for public comment, a regulatory flexibility 
analysis that describes the effect of the rule on small entities (i.e., 
small businesses, small organizations, and small governmental 
jurisdictions). However, regulatory flexibility analysis is not 
required if the head of an agency certifies that the rule will not have 
a ``significant'' economic impact on a substantial number of small 
entities.
    SBREFA amended the Regulatory Flexibility Act to require Federal 
agencies to provide a statement of the factual basis for certifying 
that a rule will not have a ``significant'' economic impact on a 
substantial number of small entities. The following discussion explains 
EPA's determination.
    EPA has examined this rule's potential effects on small entities as 
required by the RFA/SBREFA, and has determined that this action will 
not have a significant economic impact on a substantial number of small 
entities. This is evidenced by the fact that only one of the 
potentially affected, parent companies determined to be producers of 
chlorinated aliphatic products in the U.S., may be classified as a 
``small business,'' according to the U.S. Small Business 
Administration's employee size standards (i.e., less than or equal to 
1,000 employees) and according to that company's primary Standard 
Industrial Classification (SIC) code (SIC 2869).
    I hereby certify that this rule will not have a significant 
economic impact on a substantial number of small entities. This rule, 
therefore, does not require a regulatory flexibility analysis.

C. Paperwork Reduction Act

    The information collection requirements in this proposed rule have 
been submitted for approval to the Office of Management and Budget 
(OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. An 
Information Collection Request (ICR) document was prepared by EPA (ICR 
No. 1924.01) and a copy may be obtained from Sandy Farmer by mail at OP 
Regulatory Information Division; U.S. Environmental Protection Agency 
(2137); 401 M Street, S.W.; Washington, D.C. 20460, by E-mail at 
[email protected], or by calling (202) 260-2740. A copy also 
may be downloaded off the Internet at http://www.epa.gov/icr.
    This proposed rule includes new information collection requirements 
subject to OMB review under the Paperwork Reduction Act of 1995, 44 
U.S.C. 3501 et seq. In addition to complying with the existing subtitle 
C recordkeeping and reporting requirements for the newly listed waste 
streams, EPA is proposing that facilities generating chlorinated 
aliphatic wastewaters comply with testing requirements. In conjunction 
with testing requirements, we are proposing that generators maintain 
documentation of detailed standard operating procedures for the 
sampling and

[[Page 46529]]

analysis protocols that were employed, sensitivity and bias of the 
measurement process, precision of the results, and the analytical 
results from testing events. These requirements are being proposed to 
ensure generators are complying with the proposed technical standards 
for controlling air emissions of dioxins from wastewater treatment 
tanks.
    EPA also is proposing that generators be able to document their 
compliance with the conditions provided for exclusion from the scope of 
the two conditional hazardous waste listings proposed in today's 
notice. This requirement is necessary to ensure that both EDC/VCM 
wastewater treatment sludges and VCM-A wastewater treatment sludges are 
managed in a manner that is safe for human health and the environment. 
In addition, EPA is requiring' disposal facilities that manage VCM-A 
wastewater treatment sludges to maintain records documenting that these 
sludges are co-disposed only with other wastes that have a pH level of 
6.0 or lower. This requirement is necessary to ensure that the mercury 
contained in the waste does not leach from the waste after disposal.
    The Agency estimated the burden associated with complying with the 
requirements in this proposed rule. Included in the ICR are the burden 
estimates for the following requirements for industry respondents: 
reading the regulations; performing testing and waste analyses; keeping 
records of testing results; completing and submitting certifications; 
incorporating testing and waste analysis requirements into permits; 
keeping records documenting compliance with conditions for exclusion 
from hazardous waste listings; and keeping records documenting 
compliance with landfill waste disposal requirements for the disposal 
of VCM-A wastewater treatment sludges. Included also are the burden 
estimates for State respondents for applying for State authorization. 
The Agency determined that all of this information is necessary to 
ensure compliance with today's proposed rule.
    To the extent that this rule imposes any information collection 
requirements under existing RCRA regulations promulgated in previous 
rulemakings, those requirements have been approved by the Office of 
Management and Budget (OMB) under the Paperwork Reduction Act, 44 
U.S.C. 3501 et seq., and have been assigned OMB control numbers 2050-
0009 (ICR No. 1573, Part B Permit Application, Permit Modifications, 
and Special Permits); 2050-0120 (ICR No. 1571, General Facility 
Hazardous Waste Standards); 2050-0028 (ICR No. 261, Notification of 
Hazardous Waste Activity); 2050-0034 (ICR No. 262, RCRA Hazardous Waste 
Permit Application and Modification, Part A); 2050-0039 (ICR No. 801, 
Requirements for Generators, Transporters, and Waste Management 
Facilities under the Hazardous Waste Manifest System); 2050-0035 (ICR 
No. 820, Hazardous Waste Generator Standards); and 2050-0024 (ICR No. 
976, 1997 Hazardous Waste Report).
    EPA estimates that the projected annual hour burden for industry 
respondents will be 1,088 hours, and cost of $184,186. Total estimates 
over three years are 3,264 hours and $552,558.
    Burden means the total time, effort, or financial resources 
expended by persons to generate, maintain, retain, or disclose or 
provide information to or for a Federal agency. This includes the time 
needed to review instructions; develop, acquire, install, and use 
technology and systems for the purposes of collecting, validating, and 
verifying information, processing and maintaining information, and 
disclosing and providing information; adjust the existing ways to 
comply with any previously applicable instructions and requirements; 
train personnel to be able to respond to a collection of information; 
search data sources; complete and review the collection of information; 
and transmit or otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations are listed in 40 CFR Part 9 and 48 CFR Chapter 15.
    Comments are requested on the Agency's need for this information, 
the accuracy of the provided burden estimates, and any suggested 
methods for minimizing respondent burden, including through the use of 
automated collection techniques. Send comments on the ICR to the 
Director, OP Regulatory Information Division; U.S. Environmental 
Protection Agency (2137); 401 M Street, S.W.; Washington, D.C. 20460; 
and to the Office of Information and Regulatory Affairs, Office of 
Management and Budget, 725 17th Street, N.W.; Washington, D.C. 20503, 
marked ``Attention: Desk Officer for EPA.'' Include the ICR number in 
any correspondence. Since OMB is required to make a decision concerning 
the ICR between 30 and 60 days after August 25, 1999, a comment to OMB 
is best assured of having its full effect if OMB receives it by 
September 24, 1999. The final rule will respond to any OMB and public 
comments on the information collection requirements contained in this 
proposal.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Pub. 
L. 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and tribal 
governments and the private sector. Under Section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures by State, local, and tribal governments, in 
the aggregate, or by the private sector, of $100 million or more in any 
one year. Before promulgating an EPA rule for which a written statement 
is needed, Section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective or least burdensome alternative 
that achieves the objectives of the rule. The provisions of Section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
Section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective or least burdensome alternative if the 
Administrator publishes with the final rule an explanation why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including tribal governments, it must have developed under 
Section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments to have meaningful and timely 
input in the development of EPA regulatory proposals with significant 
Federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    The Agency's analysis for compliance with the UMRA found that the 
proposed action imposes less than the $100 million expenditure 
threshold on the private sector; thus, today's rule is not subject to 
the requirements of Sections 202 and 205 of UMRA.

E. Executive Order 12875: Enhancing the Intergovernmental Partnership

    Under Executive Order 12875, EPA may not issue a regulation that is 
not required by statute and that creates a mandate upon a State, local 
or tribal government, unless the Federal government provides the funds

[[Page 46530]]

necessary to pay the direct compliance costs incurred by those 
governments, or EPA consults with those governments. If EPA complies by 
consulting, Executive Order 12875 requires EPA to provide to the Office 
of Management and Budget a description of the extent of EPA's prior 
consultation with representatives of affected State, local and tribal 
governments, the nature of their concerns, any written communications 
from the governments, and a statement supporting the need to issue the 
regulation. In addition, Executive Order 12875 requires EPA to develop 
an effective process permitting elected officials and other 
representatives of State, local and tribal governments ``to provide 
meaningful and timely input in the development of regulatory proposals 
containing significant unfunded mandates.''

F. Executive Order 13084: Consultation and Coordination With Indian 
Tribal Governments

    Under Executive Order 13084, EPA may not issue a regulation that is 
not required by statute, that significantly or uniquely affects the 
communities of Indian tribal governments, and that imposes substantial 
direct compliance costs on those communities, unless the Federal 
government provides the funds necessary to pay the direct compliance 
costs incurred by the tribal governments, or EPA consults with those 
governments. If EPA complies by consulting, Executive Order 13084 
requires EPA to provide to the Office of Management and Budget, in a 
separately identified section of the preamble to the rule, a 
description of the extent of EPA's prior consultation with 
representatives of affected tribal governments, a summary of the nature 
of their concerns, and a statement supporting the need to issue the 
regulation. In addition, Executive Order 13084 requires EPA to develop 
an effective process permitting elected officials and other 
representatives of Indian tribal governments ``to provide meaningful 
and timely input in the development of regulatory policies on matters 
that significantly or uniquely affect their communities.''
    Today's rule does not significantly or uniquely affect the 
communities of Indian tribal governments. There is no impact to tribal 
governments as the result of the proposed action. In addition, this 
proposed rule is required by statute (HSWA). Accordingly, the 
requirements of Section 3(b) of Executive Order 13084 do not apply to 
this rule.

G. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    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 
proposed rule is not subject to the Executive Order because it is not 
economically significant as defined in E.O. 12866, and because the 
Agency does not have reason to believe the environmental health or 
safety risks addressed by this action present a disproportionate risk 
to children.
    The topic of environmental threats to children's health is growing 
in regulatory importance as scientists, policy makers, and village 
leaders continue to recognize the extent to which children are 
particularly vulnerable to environmental hazards. Recent EPA actions 
have been in the forefront of addressing environmental threats to the 
health and safety of children. Today's proposed rule further reflects 
our commitment to mitigating environmental threats to children.
    A few significant physiological characteristics are largely 
responsible for children's increased susceptibility to environmental 
hazards. First, children eat proportionately more food, drink 
proportionately more fluids, and breathe more air per pound of body 
weight than do adults. As a result, children potentially experience 
greater levels of exposure to environmental threats than do adults. 
Second, because children's bodies are still in the process of 
development, their immune systems, neurological systems, and other 
immature organs can be more easily and considerably affected by 
environmental hazards.
    Today's proposed rule will reduce risks posed by the hazardous 
constituents found in the listed waste streams by requiring more 
appropriate and safer management practices. EPA considered risks to 
children in its risk assessment. The more appropriate and safer 
management practices proposed in this rule are projected to reduce 
risks to children potentially exposed to the constituents of concern. 
The public is invited to submit or identify peer-reviewed studies and 
data, of which the agency may not be aware, that assess results of 
early life exposure to the proposed hazardous constituents from 
wastewaters and wastewater treatment sludges from the production of 
chlorinated aliphatic chemicals.

H. National Technology Transfer and Advancement Act of 1995

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Pub. L. No. 104-113, Section 12(d) (15 U.S.C. 
272 note) directs EPA to use voluntary consensus standards in its 
regulatory activities, unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. The NTTAA directs EPA 
to provide Congress, through OMB, explanations when the Agency decides 
not to use available and applicable voluntary consensus standards.
    This proposed rulemaking does not involve technical standards. 
Therefore, EPA is not considering the use of any voluntary consensus 
standards.

I. Executive Order 12898: Environmental Justice

    Under Executive Order 12898, ``Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations,'' as well as through EPA's April 1995, ``Environmental 
Justice Strategy, OSWER Environmental Justice Task Force Action Agenda 
Report,'' and National Environmental Justice Advisory Council, EPA has 
undertaken to incorporate environmental justice into its policies and 
programs. EPA is committed to addressing environmental justice 
concerns, and is assuming a leadership role in environmental justice 
initiatives to enhance environmental quality for all residents of the 
United States. The Agency's goals are to ensure that no segment of the 
population, regardless of race, color, national origin, or income, 
bears disproportionately high and adverse human health and 
environmental effects as a result of EPA's policies, programs, and 
activities.
    Today's proposed rule is intended to reduce risks of hazardous 
wastes as proposed, and to benefit all populations. As such, this rule 
is not expected to cause any disproportionately high and adverse 
impacts to minority or low-

[[Page 46531]]

income communities versus non-minority or affluent communities.
    In making hazardous waste listing determinations, we base our 
evaluations of potential risk from the generation and management of 
solid wastes on an analysis of potential individual risk. In conducting 
risk evaluations, our goal is to estimate potential risk to any 
population of potentially exposed individuals (e.g., home gardeners, 
adult farmers, children of farmers, anglers) located in the vicinity of 
any generator or facility handling a waste. Therefore, we are not 
putting poor, rural, or minority populations at any disadvantage with 
regard to our evaluation of risk or with regard to how the Agency makes 
its proposed hazardous waste listing determinations.
    In proposing today to list three wastes as hazardous (i.e., 
chlorinated aliphatic wastewaters, EDC/VCM wastewater treatment sludges 
managed in land treatment units, and VCM-A wastewater treatment 
sludges), all populations potentially exposed to these wastes or 
potentially exposed to releases of the hazardous constituents in the 
wastes will benefit from the proposed listing determination. In 
addition, listing determinations are effected at the national level. 
The wastes proposed to be listed as hazardous will be hazardous 
regardless of where they are generated and regardless of where they may 
be managed. Although the Agency understands that the proposed listing 
determinations, if finalized, may affect where these wastes are managed 
in the future (in that hazardous wastes must be managed at subtitle C 
facilities), the Agency's decision to list these wastes as hazardous is 
independent of any decisions regarding the location of waste generators 
and the siting of waste management facilities.
    Similarly, in cases where the Agency is proposing not list a solid 
waste as hazardous because the waste does not meet the criteria for 
being identified as a hazardous waste, these decisions are based upon 
an evaluation of potential individual risks located in proximity to any 
facility handling the waste. In the case of wastewater treatment 
sludges from the production of allyl chloride and methyl chloride and 
the case of EDC/VCM wastewater treatment sludges managed in landfills, 
we believe the potential risk levels associated with the wastes are 
safe for all populations potentially exposed to the wastes and their 
constituents.
    The Agency is soliciting comment and input from all stakeholders, 
including members of the environmental justice community and members of 
the regulated community. We encourage all interested parties to provide 
comments or further information related to potential environmental 
justice concerns or impacts, including information and data on 
facilities that have evaluated potential ecological and human health 
impacts (taking into account subsistence patterns and sensitive 
populations) to minority or low-income communities.

List of Subjects

40 CFR Part 148

    Administrative practice and procedure, Hazardous waste, Reporting 
and recordkeeping requirements, Water supply.

40 CFR Part 261

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

40 CFR Part 264

    Environmental protection, Air pollution control, Hazardous waste, 
Insurance, Packaging and containers, Reporting and recordkeeping 
requirements, Security measures, Surety bonds.

40 CFR Part 265

    Air pollution control, Hazardous waste, Insurance, Packaging and 
containers, Reporting and recordkeeping requirements, Security 
measures, Surety bonds, Water supply.

40 CFR Part 268

    Environmental protection, Hazardous materials, Reporting and 
recordkeeping requirements, Waste management.

40 CFR Part 271

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

40 CFR Part 302

    Environmental protection, Air pollution control, Chemicals, 
Hazardous chemicals, Hazardous materials, Hazardous materials 
transportation, Hazardous substances, Hazardous waste, 
Intergovernmental relations, Natural resources, Reporting and 
recordkeeping requirements, Superfund, Waste treatment and disposal, 
Water pollution control, Water supply.

    Dated: July 30, 1999.
Carol M. Browner,
Administrator.

    For the reasons set forth in the preamble, title 40, chapter I of 
the Code of Federal Regulations is proposed to be amended as follows:

PART 148--HAZARDOUS WASTE INJECTION RESTRICTIONS

    1. The authority citation for part 148 continues to read as 
follows:

    Authority: Sec. 3004, Resource Conservation and Recovery Act, 42 
U.S.C. 6901 et seq.

    2. Section 148.18 is amended by adding paragraphs (l) and (m) to 
read as follows:


Sec. 148.18  Waste-specific prohibitions--newly listed and identified 
wastes.

* * * * *
    (l) Effective [date six months after publication of final rule], 
the wastes specified in 40 CFR 261.32 as EPA Hazardous Waste Numbers 
K173, K174, and K175 are prohibited from underground injection.
    (m) The requirements of paragraphs (a) through (l) of this section 
do not apply:
    (1) If the wastes meet or are treated to meet the applicable 
standards specified in subpart D of part 268 of this chapter; or
    (2) If an exemption from a prohibition has been granted in response 
to a petition under subpart C of this part; or
    (3) During the period of extension of the applicable effective 
date, if an extension has been granted under Sec. 148.4.

PART 261--IDENTIFICATION AND LISTING OF HAZARDOUS WASTE

    3. The authority citation for part 261 continues to read as 
follows:

    Authority: 42 U.S.C. 6905, 6912(a), 6921, 6922, 6924(y), and 
6938.

    4. Section 261.3 is amended by adding a paragraph (c)(2)(ii)(F) to 
read as follows:


Sec. 261.3  Definition of hazardous waste.

* * * * *
    (c) * * *
    (2) * * *
    (ii) * * *
    (F) Wastewater treatment sludges derived from the treatment of 
chlorinated aliphatic wastewaters listed in Sec. 261.32 as EPA 
Hazardous Waste No. K173. However, this paragraph does not exempt from 
the definition of hazardous waste any wastewater treatment sludges that 
are explicity listed (e.g., K174, K175) or that meet any other listing 
in

[[Page 46532]]

subpart D of this part, as a result of the derived-from rule.
* * * * *
    5. Section 261.4 is amended by revising paragraph (b)(15) to read 
as follows:


Sec. 261.4  Exclusions.

* * * * *
    (b) * * *
    (15) Leachate or gas condensate collected from landfills where 
certain solid wastes have been disposed, provided that:
    (i) The solid wastes disposed would meet one or more of the listing 
descriptions for Hazardous Waste Codes K169, K170, K171, K172, K174, 
and K175 if these wastes had been generated after the effective date of 
the listing;
    (ii) The solid wastes described in paragraph (b)(15)(i) of this 
section were disposed prior to the effective date of the listing:
    (iii) The leachate or gas condensate do not exhibit any 
characteristic of hazardous waste nor are derived from any other listed 
hazardous waste;
    (iv) Discharge of the leachate or gas condensate, including 
leachate or gas condensate transferred from the landfill to a POTW by 
truck, rail, or dedicated pipe, is subject to regulation under Sections 
307(b) or 402 of the Clean Water Act.
    (v) After February 13, 2001, leachate or gas condensate derived 
from K169-K172 will no longer be exempt if it is stored or managed in a 
surface impoundment prior to discharge. After [date 24 months after 
publication date of the final rule], leachate or gas condensate derived 
from K175 will no longer be exempt if it is stored or managed in a 
surface impoundment prior to discharge. There is one exception: if the 
surface impoundment is used to temporarily store leachate or gas 
condensate in response to an emergency situation (e.g., shutdown of 
wastewater treatment system), provided the impoundment has a double 
liner, and provided the leachate or gas condensate is removed from the 
impoundment and continues to be managed in compliance with the 
conditions of this paragraph (b)(15)(v) after the emergency ends.
* * * * *
    6. In Sec. 261.32, the table is amended by adding in alphanumeric 
order (by the first column) the following waste streams to the subgroup 
``Organic Chemicals'' to read as follows:


Sec. 261.32  Hazardous waste from specific sources.

* * * * *

------------------------------------------------------------------------
Industry and EPA hazardous
         waste No.               Hazardous waste          Hazard code
------------------------------------------------------------------------
 
*                  *                  *                  *
                  *                  *                  *
Organic Chemicals:
 
*                  *                  *                  *
                  *                  *                  *
    K173..................  Wastewaters from the       (T)
                             production of
                             chlorinated aliphatic
                             hydrocarbons, except
                             wastewaters generated
                             from the production of
                             vinyl chloride monomer
                             using mercuric chloride
                             catalyst in an acetylene-
                             based process. This
                             listing includes
                             wastewaters from the
                             production of
                             chlorinated aliphatic
                             hydrocarbons having
                             carbon chain lengths
                             ranging from one to and
                             including five, with
                             varying amounts and
                             positions of chlorine
                             substitution.
    K174..................  Wastewater treatment       (T)
                             sludges from the
                             production of ethylene
                             dichloride or vinyl
                             chloride monomer
                             (including sludges that
                             result from commingled
                             ethylene dichloride or
                             vinyl chloride monomer
                             wastewater and other
                             wastewater), unless the
                             sludges meet the
                             following conditions:
                             they are disposed of in
                             a subtitle C or D
                             landfill licensed or
                             permitted by the state
                             or federal government;
                             they are not otherwise
                             placed on the land prior
                             to final disposal; and
                             the generator maintains
                             documentation
                             demonstrating that the
                             waste was either
                             disposed of in an on-
                             site landfill or
                             consigned to a
                             transporter or disposal
                             facility that provided a
                             written commitment to
                             dispose of the waste in
                             an off-site landfill.
                             Respondents in any
                             action brought to
                             enforce the requirements
                             of subtitle C must, upon
                             a showing by the
                             government that the
                             respondent managed
                             wastewater treatment
                             sludges from the
                             production of vinyl
                             chloride monomer or
                             ethylene dichloride,
                             demonstrate that they
                             meet the terms of the
                             exclusion set forth
                             above. In doing so, they
                             must provide appropriate
                             documentation (e.g.,
                             contracts between the
                             generator and the
                             landfill owner/operator,
                             invoices documenting
                             delivery of waste to
                             landfill, etc.) that the
                             terms of the exclusion
                             were met.
    K175..................  Option 1: Wastewater       (T)
                             treatment sludges from
                             the production of vinyl
                             chloride monomer using
                             mercuric chloride
                             catalyst in an acetylene-
                             based process.
                            Option 2: Wastewater       (T)
                             treatment sludges from
                             the production of vinyl
                             chloride monomer using
                             mercuric chloride
                             catalyst in an acetylene-
                             based process, unless
                             the sludges are disposed
                             in a subtitle C
                             landfill; and the
                             sludges do not fail the
                             toxicity characteristic
                             for mercury in 40 CFR
                             261.24; and the
                             generator maintains
                             documentation
                             demonstrating that the
                             waste was disposed of in
                             a subtitle C landfill or
                             consigned to a
                             transporter or disposal
                             facility that provided a
                             written commitment to
                             dispose of the waste in
                             a subtitle C landfill.
                             Respondents in any
                             action brought to
                             enforce the requirements
                             of subtitle C must, upon
                             a showing by the
                             government that the
                             respondent managed
                             wastewater treatment
                             sludges from the
                             production of vinyl
                             chloride monomer using
                             mercuric chloride
                             catalyst in an acetylene-
                             based process,
                             demonstrate that they
                             meet the terms of the
                             exclusion set forth
                             above. In doing so, they
                             must provide appropriate
                             documentation (e.g.,
                             contracts between the
                             generator and the
                             landfill owner/operator,
                             invoices documenting
                             delivery of waste to
                             landfill, analytical
                             results or other
                             information showing the
                             waste does not fail the
                             toxicity characteristic
                             for mercury, etc.) that
                             the terms of the
                             exclusion were met.
 
*                  *                  *                  *
                  *                  *                  *
------------------------------------------------------------------------

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

[[Page 46533]]

Appendix VII to Part 261--Basis for Listing Hazardous Waste

 
------------------------------------------------------------------------
 EPA hazardous waste No.      Hazardous constituents for which listed
------------------------------------------------------------------------
 
*                  *                  *                  *
                  *                  *                  *
K173.....................  1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin
                            (1,2,3,4,6,7,8-HpCDD), 1,2,3,4,6,7,8-
                            Heptachlorodibenzofuran (1,2,3,4,6,7,8,-
                            HpCDF), 1,2,3,4,7,8,9-
                            Heptachlorodibenzofuran (1,2,3,6,7,8,9-
                            HpCDF), HxCDDs (All Hexachlorodibenzo-p-
                            dioxins), HxCDFs (All
                            Hexachlorodibenzofurans), PeCDDs (All
                            Pentachlorodibenzo-p-dioxins), OCDD
                            (1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin,
                            OCDF (1,2,3,4,6,7,8,9-
                            Octachlorodibenzofuran), PeCDFs (All
                            Pentachlorodibenzofurans), TCDDs (All
                            tetrachlorodi-benzo-p-dioxins), TCDFs (All
                            tetrachlorodibenzofurans).
K174.....................  1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin
                            (1,2,3,4,6,7,8-HpCDD), 1,2,3,4,6,7,8-
                            Heptachlorodibenzofuran (1,2,3,4,6,7,8,-
                            HpCDF), 1,2,3,4,7,8,9-
                            Heptachlorodibenzofuran (1,2,3,6,7,8,9-
                            HpCDF), HxCDDs (All Hexachlorodibenzo-p-
                            dioxins), HxCDFs (All
                            Hexachlorodibenzofurans), PeCDDs (All
                            Pentachlorodibenzo-p-dioxins), OCDD
                            (1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin,
                            OCDF (1,2,3,4,6,7,8,9-
                            Octachlorodibenzofuran) PeCDFs (All
                            Pentachlorodibenzofurans), TCDDs (All
                            tetrachlorodi-benzo-p-dioxins), TCDFs (All
                            tetrachlorodibenzofurans).
K175.....................  Mercury
------------------------------------------------------------------------

    8. Appendix VIII to part 261 is amended by adding in alphabetical 
sequence of common name the following entries:

Appendix VIII to Part 261--Hazardous Constituents

----------------------------------------------------------------------------------------------------------------
                                                                                     Chemical        Hazardous
                  Common name                        Chemical abstracts name      abstracts  No.     waste No.
----------------------------------------------------------------------------------------------------------------
 
*                  *                  *                  *                  *                  *
                                                        *
Octachlorodibenzo-p-dioxin (OCDD).............  1,2,3,4,6,7,8,9-                       3268-87-9  ..............
                                                 Octachlorodibenzo-p-dioxin.
Octachlorodibenzofuran (OCDF).................  1,2,3,4,6,7,8,9-                      39001-02-0  ..............
                                                 Octachlorodibenzofuran.
 
*                  *                  *                  *                  *                  *
                                                        *
----------------------------------------------------------------------------------------------------------------

PART 264--STANDARDS FOR OWNERS AND OPERATORS OF HAZARDOUS WASTE 
TREATMENT, STORAGE, AND DISPOSAL FACILITIES

    9. The authority citation for part 264 continues to read as 
follows:

    Authority: 42 U.S.C. 6905, 6912(a), 6924, and 6925.

Subpart A--General

    10. Section 264.1 is amended by adding a sentence to the end of 
paragraph (g)(6) to read as follows:


Sec. 264.1  Purpose, scope and applicability.

* * * * *
    (g) * * *
    (6) * * * However, if the owner or operator is managing EPA 
Hazardous Waste No. K173 (chlorinated aliphatic wastewater) in a tank, 
the owner/operator must comply with Sec. 264.1080(h).
* * * * *

Subpart CC--Air Emission Standards for Tanks, Surface Impoundments, 
and Containers

    11. Section 264.1080 is amended by adding paragraph (h) to read as 
follows:


Sec. 264.1080  Applicability.

* * * * *
    (h) Notwithstanding the applicability requirements in paragraph (a) 
of this section, any tank (including wastewater treatment units as 
defined in Sec. 260.10 of this chapter) managing EPA Hazardous Waste 
No. K173, where the dioxin concentration in the influent wastewater to 
the tank is greater than or equal to 1 ng/L TCDD TEQ at a 95% upper 
confidence limit around the mean, must comply with the requirements of 
this paragraph, and with Sec. 264.1084 as appropriate. In order to 
determine whether the influent concentration of EPA Hazardous Waste No. 
K173 is greater than or equal to 1 ng/L TCDD TEQ at a 95% upper 
confidence limit around the mean, the generator or owner/operator must 
comply with the requirements in 40 CFR 265.1080(h)(1) through (5).

PART 265--INTERIM STATUS STANDARDS FOR OWNERS AND OPERATORS OF 
HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES

    12. The authority citation for part 265 continues to read as 
follows:

    Authority: 42 U.S.C. 6905, 6906, 6912, 6922, 6923, 6924, 6925, 
6935, 6936, and 6937, unless otherwise noted.

Subpart A--General

    13. Section 265.1 is amended by adding a sentence to the end of 
paragraph (c)(10) to read as follows:


Sec. 265.1  Purpose, scope, and applicability.

* * * * *
    (c) * * *
    (10) * * * However, if the owner or operator is managing EPA 
Hazardous Waste No. K173 (chlorinated aliphatic wastewater) in a tank, 
the owner/operator must comply with Sec. 265.1080(h).
* * * * *

Subpart CC--Air Emission Standards for Tanks, Surface Impoundments, 
and Containers

    14. Section 265.1080 is amended by adding paragraph (h) to read as 
follows:


Sec. 265.1080  Applicability

* * * * *
    (h) Notwithstanding the applicability requirements in paragraph (a) 
of this section, any tank (including wastewater treatment units as 
defined in Sec. 260.10 of this chapter) managing EPA Hazardous Waste 
No. K173, where the dioxin concentration in the influent wastewater to 
the tank is equal to or greater than 1 ng/L TCDD TEQ at a 95% upper 
confidence limit around the mean, must

[[Page 46534]]

comply with the requirements of this paragraph, and with Sec. 265.1085 
as appropriate. In order to determine whether the influent 
concentration of EPA Hazardous Waste No. K173 is greater than or equal 
to 1 ng/L TCDD TEQ at a 95% upper confidence limit around the mean, the 
generator or owner/operator must comply with the following:
    (1) Waste sampling and analysis plans. (i) General. The generator 
of K173 shall develop and follow a written waste sampling and analysis 
plan which describes the procedures for sampling and analysis of the 
hazardous waste at the influent to each wastewater treatment tank to be 
excluded from the requirements of this part. The waste sampling and 
analysis plan shall be developed in accordance with the applicable 
sections of the ``Test Methods for Evaluating Solid Waste, Physical/
Chemical Methods'' (SW-846) or other appropriate guidance. The plan 
shall be followed and retained at the facility claiming an exemption 
for one or more wastewater treatment tanks.
    (ii) At a minimum, the plan must include:
    (A) A detailed description of the test method(s) used to test for 
2,3,7,8-substituted chlorinated dibenzo-p-dioxin (CDD) and 2,3,7,8-
substituted chlorinated dibenzo-p-furan (CDF) congeners;
    (B) The sampling method used to obtain representative samples of 
each wastewater tank influent; and
    (C) How the design of the sampling program accounts for any 
expected fluctuations in concentrations over time, while ensuring that 
the samples collected are grab samples and that all samples are 
collected within a timeframe that will allow for the analyses to 
account for potential variabilities in the wastestream.
    (2) Sampling and analysis. (i) General. For each wastewater 
treatment tank for which an exemption is claimed, the generator of K173 
must:
    (A) Test for all 2,3,7,8-substituted CDDs/CDFs; or
    (B) Use process knowledge for tanks downstream of a tank that is 
exempt as a result of testing specified in paragraph (h)(2)(i)(A) of 
this section.
    (ii) The K173 generator may use any reliable analytical method to 
demonstrate that the TCDD TEQ does not exceed the trigger level. It is 
the responsibility of the generator to ensure that the sampling and 
analysis are unbiased, precise, and representative of the waste.
    (iii) The generator must ensure that the measurements are 
sufficiently sensitive, accurate and precise to demonstrate that the 
maximum TCDD TEQ in any sample analyzed does not exceed the specified 
trigger level.
    (iv) For the tank to be eligible for exemption, a generator must 
demonstrate that:
    (A) The maximum TCDD TEQ in the influent to the tank does not 
exceed 1 ng/L at the 95% upper confidence limit around the mean;
    (B) The TCDD TEQ for each sample shall be determined by multiplying 
the concentration of any 2,3,7,8-substituted CDD or CDF detected and 
the appropriate toxicity equivalency factor (TEF), as described below, 
and summing these products for each sample;
    (C) The following toxicity equivalence factors shall be used:

------------------------------------------------------------------------
                          Compound                              WHO-TEF
------------------------------------------------------------------------
2,3,7,8-TetraCDD............................................      1
1,2,3,7,8-PentaCDD..........................................      1
1,2,3,4,7,8-HexaCDD.........................................      0.1
1,2,3,7,8,9-HexaCDD.........................................      0.1
1,2,3,6,7,8-HexaCDD.........................................      0.1
1,2,3,4,6,7,8-HeptaCDD......................................      0.01
1,2,3,4,5,7,8,9-OctaCDD.....................................      0.0001
2,3,7,8-TetraCDF............................................      0.1
2,3,4,7,8-PentaCDF..........................................      0.5
1,2,3,7,8-PentaCDF..........................................      0.05
1,2,3,4,7,8-HexaCDF.........................................      0.1
1,2,3,7,8,9-HexaCDF.........................................      0.1
1,2,3,6,7,8-HexaCDF.........................................      0.1
2,3,4,6,7,8-HexaCDF.........................................      0.1
1,2,3,4,7,8,9-HeptaCDF......................................      0.01
1,2,3,4,6,7,8-HeptaCDF......................................      0.01
1,2,3,4,6,7,8,9-OctaCDF.....................................      0.0001
------------------------------------------------------------------------

    (D) The analysis could have detected the presence of the CDD/CDF 
congeners at or below the trigger level of 1 ng/L at the 95% upper 
confidence limit around the mean.
    (v) In an enforcement action, the burden of proof to establish 
conformance with the exemption specification shall be on the generator 
claiming the exclusion.
    (vi) The generator must conduct sampling and analysis in accordance 
with their waste sampling and analysis plan developed under paragraph 
(h)(1) of this section.
    (vii) The influent to exempt wastewater treatment tanks must be re-
tested, at a minimum, annually and must be retested after a process 
change that could change the TCDD TEQ level in the waste.
    (3) Records. The generator must maintain records of the following 
information on-site:
    (i) All information required to be submitted to the implementing 
authority as part of the notification of the claim:
    (A) The owner/operator name, address, and RCRA facility ID number 
of the person claiming the exemption; and
    (B) The certification signed by the person claiming the exclusion 
or his authorized representative.
    (ii) A brief description of the tanks covered by the claimed 
exemption, including dimensions and service in the wastewater treatment 
system;
    (iii) A description and process flow diagram of the wastewater 
treatment system, clearly identifying the exempt tanks and sampling 
points;
    (iv) The results of all analyses and all detection limits achieved 
as required under paragraph (h)(2) of this section;
    (v) The waste sampling and analysis plan;
    (vi) The results of the sampling and analysis, including the 
following:
    (A) The dates and times waste samples were obtained, and the dates 
the samples were analyzed;
    (B) The names and qualifications of the person(s) who obtained the 
samples;
    (C) A description of the temporal and spatial locations of the 
samples;
    (D) The name and address of the laboratory facility at which 
analyses of the samples were performed;
    (E) A detailed description of the analytical methods used, 
including any clean-up and sample preparation methods;
    (F) All quantitation limits achieved and all other quality control 
results for the analysis (including method blanks, duplicate analyses, 
matrix spikes, etc.), laboratory quality assurance data, and 
description of any deviations from analytical methods written in the 
plan or from any other activity written in the plan which occurred;
    (G) All laboratory analytical results demonstrating that the 
trigger exemption level has not been exceeded at the tank influent, for 
each exempt tank; and
    (H) All laboratory documentation that support the analytical 
results, unless a contract between the claimant and the laboratory 
provides for the documentation to be maintained by the laboratory for 
the period specified in paragraph (h)(4) of this section and also 
provides for the availability of the documentation to the claimant upon 
request; and
    (4) Records retention. Records must be maintained for the period of 
three years. A generator must maintain a current waste sampling and 
analysis plan during that three year period.
    (5) Notification and certification. The waste generator must submit 
a one-time notification and certification to the EPA Region or an 
authorized State (by mail or delivery service which provides return 
receipt) within 60 days following the effective date of the final rule 
or initial use of a wastewater treatment

[[Page 46535]]

tank used to manage K173. The notification must include the waste 
generator's name and address, a representative's name and telephone 
number, and a description of the wastewater treatment system and the 
assessed tanks. The certification must be signed by an authorized 
representative and must state as follows:

I certify under penalty of law that the influent(s) to the tanks 
identified in this certification do not exceed 1 ng/L TCDD TEQ. I am 
aware that there are significant penalties for submitting a false, 
inaccurate, or incomplete certification, including the possibility 
of fine and imprisonment.

PART 268--LAND DISPOSAL RESTRICTIONS

    15. The authority citation for part 268 continues to read as 
follows:

    Authority: 42 U.S.C. 6905, 6912(a), 6921, and 6924.

Subpart A--General

    16. Section 268.7 is amended by adding paragraph (f) to read as 
follows:


Sec. 268.7  Testing, tracking, and recordkeeping requirements for 
generators, treaters, and disposal facilities.

* * * * *
    (f) The owner or operator of a facility codisposing wastes with 
wastes identified as hazardous waste K175 must maintain records 
available for inspection of the pH of the wastes so codisposed.

Subpart C--Prohibitions on Land Disposal

    17. Section 268.33 is revised to read as follows:


Sec. 268.33  Waste specific prohibitions--chlorinated aliphatic wastes.

    (a) Effective [date 90 days from date of publication of final 
rule], the wastes specified in 40 CFR Part 261 as EPA Hazardous Wastes 
Numbers K173, K174, and K175, and soil and debris contaminated with 
these wastes are prohibited from land disposal.
    (b) Effective [date two years from date of publication of final 
rule], the following wastes are prohibited from land disposal: soil and 
debris contaminated with radioactive wastes mixed with EPA Hazardous 
wastes K173, K174, and K175.
    (c) Between [date of publication of final rule] and [Insert date 
two years from date of publication of final rule], radioactive waste 
mixed with K173, K174, and K175 wastes and/or soil and debris may be 
disposed in a landfill or surface impoundment only if such unit is in 
compliance with the requirements specified in Sec. 268.5(h)(2).
    (d) The requirements of paragraphs (a), (b) and (c) of this section 
do not apply if:
    (1) The wastes meet the applicable treatment standards specified in 
subpart D of this part;
    (2) Persons have been granted an exemption from a prohibition 
pursuant to a petition under Sec. 268.6, with respect to those wastes 
and units covered by the petition;
    (3) The wastes meet the applicable treatment standards established 
pursuant to a petition granted under Sec. 268.44;
    (4) Hazardous debris has met the treatment standards in Sec. 268.40 
or the alternative treatment standards in Sec. 268.45; or
    (5) Persons have been granted an extension to the effective date of 
a prohibition pursuant to Sec. 268.5, with respect to these wastes 
covered by the extension.
    (e) To determine whether a hazardous waste identified in this 
section exceeds the applicable treatment standards specified in 
Sec. 268.40, the initial generator must test a sample of the waste 
extract or the entire waste, depending on whether the treatment 
standards are expressed as concentrations in the waste extract or the 
waste, or the generator may use knowledge of the waste. If the waste 
contains regulated constituents in excess of the applicable Universal 
Treatment Standard levels of Sec. 268.48, the waste is prohibited from 
land disposal, and all requirements of this part are applicable, except 
as otherwise specified.
    (f) Disposal of K175 wastes containing mercuric sulfide is 
restricted to units to which disposal of wastes in excess of pH 6.0 is 
prohibited.
    18. In Sec. 268.40, the Table is amended in the entry for F039 to 
add constituents in alphabetical order and by adding in alphanumeric 
order new entries for K173, K174, and K175 to read as follows:


Sec. 268.40  Applicability of treatment standards.

* * * * *

                                    Treatment Standards for Hazardous Wastes
----------------------------------------------------------------------------------------------------------------
                                         Regulated hazardous constituent      Wastewaters      Nonwastewaters
                                     ---------------------------------------------------------------------------
               Waste description and                                         Concentration  Concentration in mg/
  Waste code    treatment/regulatory                                        in mg/L,\3\ or   kg \5\ unless noted
                  subcategory \1\          Common name        CAS \2\ No.     technology    as ``mg/L TCLP'', or
                                                                               code \4\        technology code
----------------------------------------------------------------------------------------------------------------
 
*                  *                  *                  *                  *                  *
                                                        *
F039.........  Leachate (liquids      1,2,3,4,6,7,8-            35822-39-4        0.000035  0.0025
                that have percolated   Heptachlorodibenzo-
                through land           p-dioxin
                disposed wastes)       (1,2,3,4,6,7,8-
                resulting from the     HpCDD).
                disposal of more
                than one restricted
                waste classified as
                hazardous under
                Subpart D of this
                part. (Leachate
                resulting from the
                disposal of one or
                more of the
                following EPA
                Hazardous Wastes and
                no other Hazardous
                Waste retains its
                EPA Hazardous Waste
                Number(s): F020,
                F021, F022, F026,
                F027, and/or F028) *
                * *.
                 ...................  1,2,3,4,6,7,8-            67562-39-4        0.000035  0.0025
                                       Heptachlorodibenzof
                                       uran (1,2,3,4,6,7,8-
                                       HpCDF).
                 ...................  1,2,3,4,7,8,9-            55673-89-7        0.000035  0.0025
                                       Heptachlorodibenzof
                                       uran (1,2,3,4,7,8,9-
                                       HpCDF).

[[Page 46536]]

 
 
*                  *                  *                  *                  *                  *
                                                        *
                                      1,2,3,4,6,7,8,9-           3268-87-9        0.000063  0.0025
                                       Octachlorodibenzo-p-
                                       dioxin (OCDD).
                                      1,2,3,4,6,7,8,9-          39001-02-0        0.000063  0.005
                                       Octachlorodibenzofu
                                       ran (OCDF).
 
*                  *                  *                  *                  *                  *
                                                        *
K173.........  Wastewaters from the   Bis(2-                      111-44-4           0.033  6.0
                production of          chloroethyl)ether.
                chlorinated
                aliphatic
                hydrocarbons, except
                wastewaters
                generated from the
                production of vinyl
                chloride monomer
                using mercuric
                chloride catalyst in
                an acetylene-based
                process. This
                listing includes
                wastewaters from the
                production of
                chlorinated
                aliphatic
                hydrocarbons having
                carbon chain lengths
                ranging from one to
                and including five,
                with varying amounts
                and positions of
                chlorine
                substitution.
                                      Chloroform..........         67-66-3           0.046  6.0
                                      Pentachlorophenol...         87-86-5           0.089  7.4
                                      Phenol..............        108-95-4           0.039  6.2
                                      2,4,6-                       88-06-2           0.035  7.4
                                       Trichlorophenol.
                                      1,2,3,4,6,7,8-            35822-39-4        0.000035  0.0025
                                       Heptachlorodibenzo-
                                       p-dioxin
                                       (1,2,3,4,6,7,8-
                                       HpCDD).
                                      1,2,3,4,6,7,8-            67562-39-4        0.000035  0.0025
                                       Heptachlorodibenzof
                                       uran (1,2,3,4,6,7,8-
                                       HpCDF).
                                      1,2,3,4,7,8,9-            55673-89-7        0.000035  0.0025
                                       Heptachlorodibenzof
                                       uran (1,2,3,4,7,8,9-
                                       HpCDF).
                                      HxCDDs (All                 0.000063           0.001
                                       Hexachloro-.
                                      dibenzo-p-dioxins)
                                       34465-46-8.
                                      HxCDFs (All               55684-94-1        0.000063  0.001
                                       Hexachloro-.
                                      dibenzofurans)......
                                      1,2,3,4,6,7,8,9-           3268-87-9        0.000063  0.005
                                       Octachlorodibenzo-p-
                                       dioxin (OCDD).
                                      1,2,3,4,6,7,8,9-          39001-02-0        0.000063  0.005
                                       Octachlorodibenzofu
                                       ran (OCDF).
                                      PeCDDs (All               36088-22-9        0.000063  0.001
                                       Pentachloro-.
                                      dibenzo-p-dioxins)..
                                      PeCDFs (All               30402-15-4        0.000035  0.001
                                       Pentachloro-.
                                      dibenzofurans)......
                                      TCDDs (All                  0.000063           0.001
                                       tetrachloro-.
                                      di-benzo-p-dioxins)
                                       41903-57-5.
                                      TCDFs (All                55722-27-5        0.000063  0.001
                                       tetrachloro-.
                                      dibenzofurans)......
                                      Chromium (Total)....       7440-47-3            2.77  0.60 mg/L TCLP
                                      Nickel..............       7440-02-0            3.98  11 mg/L TCLP
K174.........  Wastewater treatment   1,2,3,4,6,7,8-            35822-39-4        0.000035  0.0025
                sludges from the       Heptachlorodibenzo-
                production of          p-dioxin
                ethylene dichloride    (1,2,3,4,6,7,8-
                or vinyl chloride      HpCDD).
                monomer.
                                      1,2,3,4,6,7,8-            67562-39-4        0.000035  0.0025
                                       Heptachlorodibenzof
                                       uran (1,2,3,4,6,7,8-
                                       HpCDF).
                                      1,2,3,4,7,8,9-            55673-89-7        0.000035  0.0025
                                       Heptachlorodibenzof
                                       uran (1,2,3,4,7,8,9-
                                       HpCDF).
                                      HxCDDs (All               34465-46-8        0.000063  0.001
                                       Hexachloro-.
                                      dibenzo-p-dioxins)..
                                      HxCDFs (All               55684-94-1        0.000063  0.001
                                       Hexachloro-.
                                      dibenzofurans)......
                                      1,2,3,4,6,7,8,9-           3268-87-9        0.000063  0.005
                                       Octachlorodibenzo-p-
                                       dioxin (OCDD).
                                      1,2,3,4,6,7,8,9-          39001-02-0        0.000063  0.005
                                       Octachlorodibenzofu
                                       ran (OCDF).
 

[[Page 46537]]

 
                                      PeCDDs (All               36088-22-9        0.000063  0.001
                                       Pentachloro-.
                                      dibenzo-p-dioxins)..
                                      PeCDFs (All               30402-15-4        0.000035  0.001
                                       Pentachloro-.
                                      dibenzofurans)......
                                      TCDDs (All                41903-57-5        0.000063  0.001
                                       tetrachlorodi-benzo-
                                       p-dioxins).
                                      TCDFs (All                55722-27-5        0.000063  0.001
                                       tetrachlorodibenzof
                                       urans).
                                      Arsenic.............       7440-36-0             1.4  5.0 mg/L TCLP
K175.........  K175 (wastewater       Mercury.............       7438-97-6              NA  RMERC
                treatment sludge
                from the production
                of vinyl chloride
                monomer using
                mercuric chloride
                catalyst in an
                acetylene-based
                process)
                nonwastewaters that
                contain greater than
                or equal to 260 mg/
                kg total mercury.
               K175 nonwastewaters    Mercury.............       7438-97-6              NA  0.20 mg/L TCLP
                that contain less
                than 260 mg/kg total
                mercury that are
                residues from RMERC.
               Other K175             Mercury.............       7438-97-6              NA  0.025 mg/L TCLP
                nonwastewaters that
                contain less than
                260 mg/kg total
                mercury and are not
                residues from RMERC.
                                      pH..................  ..............              NA  pH <6.0
               All K175 wastewaters.  Mercury.............       7438-97-6            0.15  NA
 
*                  *                  *                  *                  *                  *
                                                        *
----------------------------------------------------------------------------------------------------------------
* Note: NA means not applicable.
\1\ The waste descriptions provided in this table do not replace waste descriptions in 40 CFR Part 261.
  Descriptions of Treatment/Regulatory Subcategories are provided, as needed, to distinguish between
  applicability of different standards.
\2\ CAS means Chemical Abstract Services. When the waste code and/or regulated constituents are described as a
  combination of a chemical with its salts and/or esters, the CAS number is given for the parent compound only.
\3\ Concentration standards for wastewaters are expressed in mg/L and are based on analysis of composite
  samples.
\4\ All treatment standards expressed as a Technology Code or combination of Technology Codes are explained in
  detail in 40 CFR 268.42 Table 1-Technology Codes and Descriptions of Technology-Based Standards.
\5\ Except for Metals (EP or TCLP) and Cyanides (Total and Amenable) the nonwastewater treatment standards
  expressed as a concentration were established, in part, based upon incineration in units operated in
  accordance with the technical requirements of 40 CFR Part 264 Subpart O or Part 265 Subpart O, or based upon
  combustion in fuel substitution units operating in accordance with applicable technical requirements. A
  facility may comply with these treatment standards according to provisions in 40 CFR 268.40(d). All
  concentration standards for nonwastewaters are based on analysis of grab samples.

    19. In Sec. 268.48(a) the Table is amended by adding in 
alphabetical order the following entries under the heading organic 
constituents: (The footnotes are republished without change.)


Sec. 268.48  Universal treatment standards.

    (a) * * *

                                          Universal Treatment Standards
----------------------------------------------------------------------------------------------------------------
                                                                                                   Nonwastewater
                                                                                                     standard
                                                                                    Wastewater     concentration
                Regulated constituent common name                 CAS \1\ number     standard      in mg/Kg \3\
                                                                                   concentration   unless noted
                                                                                    in mg/L \2\      as ``mg/L
                                                                                                      TCLP''
----------------------------------------------------------------------------------------------------------------
 
*                  *                  *                  *                  *                  *
                                                        *
1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin (1,2,3,4,6,7,8-HpCDD).      35822-39-4        0.000035          0.0025
1,2,3,4,6,7,8-Heptachlorodibenzofuran (1,2,3,4,6,7,8-HpCDF).....      67562-39-4        0.000035          0.0025
1,2,3,4,7,8,9-Heptachlorodibenzofuran (1,2,3,6,7,8,9-HpCDF).....      55673-89-7        0.000035          0.0025
 
*                  *                  *                  *                  *                  *
                                                        *
1,2,3,4,6,7,8,9-Octachlorodibenzo-p-dioxin (OCDD)...............       3268-87-9        0.000063          0.005
1,2,3,4,6,7,8,9-Octachlorodibenzofuran (OCDF)...................      39001-02-0        0.000063          0.005
 
*                  *                  *                  *                  *                  *
                                                        *

[[Page 46538]]

 
----------------------------------------------------------------------------------------------------------------
* Note: NA means not applicable.
\1\ CAS means Chemical Abstract Services. When the waste code and/or regulated constituents are described as a
  combination of a chemical with its salts and/or esters, the CAS number is given for the parent compound only.
\2\ Concentration standards for wastewaters are expressed in mg/L and are based on analysis of composite
  samples.
\3\ Except for Metals (EP or TCLP) and Cyanides (Total and Amenable) the nonwastewater treatment standards
  expressed as a concentration were established, in part, based upon incineration in units operated in
  accordance with the technical requirements of 40 CFR Part 264, Subpart O, or Part 265, Subpart O, or based
  upon combustion in fuel substitution units operating in accordance with applicable technical requirements. A
  facility may comply with these treatment standards according to provisions in 40 CFR 268.40(d). All
  concentration standards for nonwastewaters are based on analysis of grab samples.

* * * * *


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

    20. The authority citation for part 271 continues to read as 
follows:

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

    21. Section 271.1(j) is amended by adding the following entries to 
Table 1 and Table 2 in chronological order by date to read as follows.


Sec. 271.1  Purpose and scope.

* * * * *
    (j) *  *  *

    Table 1.--Regulations Implementing the Hazardous and Solid Waste
                           Amendments of 1984
------------------------------------------------------------------------
                        Title of      Federal Register
Promulgation date      regulation         reference      Effective date
------------------------------------------------------------------------
 
*                  *                  *                  *
                  *                  *                  *
[insert date of    Listing of         [insert Federal   [insert
 signature of       Hazardous Wastes   Register page     effective date
 final rule]        K173, K174, and    numbers]          of final rule]
                    K175
 
*                  *                  *                  *
                  *                  *                  *
------------------------------------------------------------------------


                  Table 2.--Self Implementing Provisions of the Solid Waste Amendments of 1984
----------------------------------------------------------------------------------------------------------------
                                                                                             Federal Register
     Effective date            Self-implementing provision             RCRA citation             reference
----------------------------------------------------------------------------------------------------------------
 
*                  *                  *                  *                  *                  *
                                                        *
[effective date of       Prohibition on land disposal of K173,    3004(g)(4)(C) and       [date of publication
 final rule].             K174, and K175 wastes, and prohibition   3004(m).                of final rule], [FR
                          on land disposal of radioactive waste                            page numbers].
                          mixed with K173, K174, and K175
                          wastes, including soil and debris.
 
*                  *                  *                  *                  *                  *
                                                        *
----------------------------------------------------------------------------------------------------------------

PART 302--DESIGNATION, REPORTABLE QUANTITIES, AND NOTIFICATION

    22. The authority citation for part 302 continues to read as 
follows:

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

    23. In Sec. 302.4, Table 302.4 is amended by adding the following 
new entries in alphanumeric order at the end of the table to read as 
follows:


Sec. 302.4  Designation of hazardous substances

* * * * *

                                           Table 302.4--List of Hazardous Substances and Reportable Quantities
                                             [Note: All Comments/Notes Are Located at the End of This Table]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                              Statutory                              Final RQ
                                                                           -----------------------------------------------------------------------------
         Hazardous substance             CASRN       Regulatory synonyms                                                                         Pounds
                                                                                RQ         Code        RCRA  waste No.          Category          (Kg)
------------------------------------------------------------------------------------------------------------------------------------------------
K173 f...............................  .........  ........................         *1            4   K173                 X                     1(0.454)
K174 f...............................  .........  ........................         *1            4   K174                 X                     1(0.454)
K175 f...............................  .........  ........................         *1            4   K175                 X                    1(0.454)
--------------------------------------------------------------------------------------------------------------------------------------------------------
 Indicates the statutory sources as defined by 1, 2, 3, and 4 below.
*                  *                  *                  *                  *
4--Indicates that the statutory source for designation of this hazardous substance under CERCLA is RCRA Section 3001.
*1--Indicates that the 1-pound RQ is a CERCLA statutory RQ.
*                  *                  *                  *                  *
f See 40 CFR 302.6(b)(1) for application of the mixture rule to this hazardous waste.


[[Page 46539]]

    24. Section 302.6 is amended by revising paragraph (b)(1)(iii) 
introductory text and by adding entries K173, K174, and K175 to the 
table in paragraph (b)(1)(iii) in numerical order to read as follows:


Sec. 302.6  Notification requirements.

* * * * *
    (b) * * *
    (1) * * *
    (iii) For waste streams K169, K170, K171, K172, K173, K174, and 
K175, knowledge of the quantity of all of the hazardous constituent(s) 
may be assumed, based on the following maximum observed constituent 
concentrations identified by EPA:

------------------------------------------------------------------------
           Waste                    Constituent              Max ppm
------------------------------------------------------------------------
 
*                  *                  *                  *
                  *                  *                  *
K173......................  2,3,7,8-TCDD..............       0.000000017
                            1,2,3,7,8-PeCDD...........       0.00000015
                            1,2,3,4,7,8-HxCDD.........       0.00000012
                            1,2,3,6,7,8-HxCDD.........       0.00000091
                            1,2,3,7,8,9-HxCDD.........       0.00000092
                            1,2,3,4,6,7,8-HpCDD.......       0.000044
                            OCDD......................       0.00022
                            2,3,7,8-TCDF..............       0.00000045
                            1,2,3,7,8-PeCDF...........       0.0000012
                            2,3,4,7,8-PeCDF...........       0.0000015
                            1,2,3,4,7,8-HxCDF.........       0.000042
                            1,2,3,6,7,8-HxCDF.........       0.000045
                            1,2,3,7,8,9-HxCDF.........       0.000014
                            2,3,4,6,7,8-HxCDF.........       0.000027
                            1,2,3,4,6,7,8-HpCDF.......       0.0013
                            1,2,3,4,7,8,9-HpCDF.......       0.00017
                            OCDF......................       0.006
                            Chloroform................       7.1
K174......................  2,3,7,8-TCDD..............       0.000039
                            1,2,3,7,8-PeCDD...........       0.0000108
                            1,2,3,4,7,8-HxCDD.........       0.0000241
                            1,2,3,6,7,8-HxCDD.........       0.000083
                            1,2,3,7,8,9-HxCDD.........       0.000062
                            1,2,3,4,6,7,8-HpCDD.......       0.00123
                            OCDD......................       0.0129
                            2,3,7,8-TCDF..............       0.000145
                            1,2,3,7,8-PeCDF...........       0.0000777
                            2,3,4,7,8-PeCDF...........       0.000127
                            1,2,3,4,7,8-HxCDF.........       0.001425
                            1,2,3,6,7,8-HxCDF.........       0.000281
                            1,2,3,7,8,9-HxCDF.........       0.00014
                            2,3,4,6,7,8-HxCDF.........       0.000648
                            1,2,3,4,6,7,8-HpCDF.......       0.0207
                            1,2,3,4,7,8,9-HpCDF.......       0.0135
                            OCDF......................       0.212
K175......................  Mercury...................    9200
------------------------------------------------------------------------

* * * * *
[FR Doc. 99-20753 Filed 8-24-99; 8:45 am]
BILLING CODE 6560-50-P