Federal  Register/Vol. 64. No.  103 /Friday. May 28,  1999 /Proposed Rules
                                                                                                           28949
List of Subjects in 40 CFR Part 52
  Environmental protection, Air
pollution control, Paniculate matter.
  Authority: 42 U.S.C. 7401 etseq.
  Dated: May 18, 1999.
William Rice,"
Acting Regional Administrator, Region VII.
[FR Doc. 99-13660 Filed 5-27-99; 8:45 ami
BILLING CODE 6560-50-P
ENVIRONMENTAL PROTECTION
AGENCY

40 CFR Part 268
[FRL-6351-4]
RIN-2050-AE54

Potential Revisions to the Land
Disposal Restrictions Mercury
Treatment Standards
AGENCY: Environmental Protection
Agency.    -
ACTION: Advance notice of proposed
rulemaking (ANPRM).

SUMMARY:  The Environmental Protection
Agency (EPA or Agency) is considering
publication of a proposed rule to revise
the 40 CFR part 268 Land Disposal
Restrictions (LDR) treatment standards
applicable to mercury-bearing wastes.
This ANPRM is intended to give
advance notice of EPA's comprehensive
reevaluation of the treatment standards
for mercury-bearing hazardous wastes as
well as various options, issues, and data
needs related to potential mercury
treatment  standard revisions. The
Agency requests additional data and
comments on these issues and options.
DATES: Written and electronic comments
in response to this ANPRM must be
received on or before July 27, 1999.
ADDRESSES: Commenters should submit
an original and two copies of their
comments referencing Docket No. F-
1999-MTSP-FFFFF to: the RCRA
Information Center (RIC), U.S.
Environmental Protection Agency
Headquarters (5305W), 401 M Street,
SW, Washington, D.C. 20460. Courier
deliveries  of comments should be
submitted to the RIC at the address
listed below. Comments may also be
submitted electronically through the
Internet to:
  RCRA-docket@epamail.epa.gov.
Comments in electronic format should
also be identified by the docket number
F-1999-MTSP-FFFFF. Submit
electronic  comments as an ASCII file
and avoid  the use of special characters
and any form of encryption. If possible,
EPA's Office of Solid Waste (OSW)
would also like to receive an additional
                    copy of the comments on disk in
                    WordPerfect 6.1 file format.
                      Commenters should not submit
                    electronically any confidential business
                    information (CBI). An original and two
                    copies of the CBI must be submitted
                    under separate cover to: Regina Magbie,
                    RCRA CBI Document Control Officer,
                    Office of Solid Waste (5305W), U.S.
                    EPA, 401 M Street, S.W., Washington,
                    D.C. 20460.
                      The Agency will consider the public
                    comments during development of any
                    proposed rule related to this action. The
                    Agency urges commenters submitting
                    data in support of their views to include
                    with the data evidence that appropriate
                    quality assurance/quality control' (QA/
                    QC) procedures were followed in
                    generating the data. Data that the
                    Agency cannot verify through QA/QC
                    documentation may be given less
                    consideration or disregarded in
                    developing regulatory options for
                    proposal and final rules.
                      Public comments and supporting
                    materials are available for viewing in
                    the RIC, located at Crystal Gateway One,
                    1235 Jefferson Davis Highway, First
                    Floor, Arlington, Virginia. The RIC is
                    open from  9 a.m.  to 4 p.m., Monday
                    through Friday, except for Federal
                    holidays. To review docket materials,
                    the public  must make an appointment
                    by calling 703-603-9230. The public
                    may copy a maximum of 100 pages from
                    any regulatory docket at no charge.
                    Additional copies cost $0.15 per page.
                    The docket index and notice are
                    available electronically. See the
                    SUPPLEMENTARY INFORMATION  section for
                    information on accessing it.
                    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
                    this document, contact Rita Chow,
                    Office of Solid Waste-(5302W), U.S.
                    Environmental Protection Agency, 401
                    M Street, S.W., Washington, D.C. 20460,
                    703-308-6158, e-mail address:
                    chow.rita@epa.gov.
                    SUPPLEMENTARY INFORMATION : The
                    docket index and the notice are
                    available on the Internet. From the
                    World Wide Web  (WWW), type http://
                    www.epa.gov/fedrgstr. For the text of
                    the notice,  choose: Year/Month/Day.
                    The document may also be obtained
                     1 For guidance, see Final Best Demonstrated
                   Available Technology (BDAT) Background
                   Document for Quality Assurance/Quality Control
                   Procedures and Methodology; USEPA, October 23,
                   1991.
 using File Transfer Protocol (FTP) at:
 ftp:epa.gov.
 Login: anonymous
 Password: your Internet address

 Glossary of Acronyms
 APCD—Air Pollution Control Device
 ATON—Aid-to-Navigation
 ATTIC—Alternative Technology
   Treatment Information Center
 BDAT—Best Demonstrated Available
   Technology
 BIF—Boiler and Industrial Furnace
 BRS—Biennial Reporting System
 DOE—Department'of Energy
 IMERC—Incineration of Wastes
   Containing Organics and Mercury
   (Specified Treatment Method)
 LDR—Land Disposal Restrictions
 MACT—Maximum Achievable Control
   Technology
 NESHAP—National Emissions Standard
   for Hazardous Air Pollutants
 NHWCS—National Hazardous waste
   Constituent Survey
 PBT—Persistent, Bioaccumulative, and
   Toxic
 PCB—Polychlorinated Biphenyls
 POTW—Publically Owned Treatment
   Works
 PSD—Prevention of Significant
   Deterioration Permit
 RCRA—Resource Conservation and
   Recovery Act
 RMERC—Roasting or Retorting of
   Mercury-Bearing Hazardous Wastes
   (Specified Treatment Method)
 RREL—Risk Reduction Engineering
   Laboratory
 S/S—Solidification/stabilization
 SPC—Sulfur Polymer Cement
 TCLP—Toxicity  Characteristic Leaching
   Procedure
 TOC—Total Organic Carbon
 TRI—Toxic Release Inventory
 VISITT—Vendor Information System for
   Innovative Treatment Technology
 WMNP—Waste Minimization National
   Plan

 Table of Contents
 I. Introduction
  A. Agency's Concern for Mercury
  B. Key Issues Addressed in the ANPRM
 II. Background
  A. Mercury in the Environment
  B. The Resource  Conservation Recovery
    Act
  C. Mercury Treatment Standards
HI. Mercury Hazardous Waste Generation and
    Management
  A. Industries Generating Mercury-Bearing
    Wastes
  B. Generation of  Mercury-Bearing
    Hazardous Wastes
IV. Current RCRA Regulations Governing
    Treatment of Mercury-Bearing
    Hazardous Wastes
  A. RCRA Waste Code Classification and
    Treatment

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 28950
Federal Register/Vol.  64, No.  103/Friday,  May 28, 1999/Proposed Rules
   B. Existing LDR Regulations for Mercury-
    Bearing Wastes
 V. Mercury Treatment Technologies-Roasting
    and Retorting of Mercury Wastes
   A. Process and Regulation
   B. Air Emissions from Roasting and
    Retorting
   C, Request for Comment
 VI, Mercury Treatment Technologies-
    Incineration of Mercury Wastes
   A, Current Regulations
   B, Characteristics of Mercury in
    Incinerators and Current Emission
    Control Systems
   C, Amount of Mercury Emitted from
    Incinerators and Other Hazardous Waste
    Combustors
   D, General Waste Characterization Data on
    Mercury in Hazardous Waste Streams
   E. EPA's Re-Evaluation of the IMERC
    Standard
   F. Additional Considerations Related to
    Alternatives to Incineration
   G, Request for Comment
 VII, Regulatory Options Involving Source
    Reduction
 VIII. Mixed Wastes
 IX, Discussion of Alternative Treatment
    Technologies
   A. Possible Alternative Technologies to
    Retorting
   B, Possible Alternative Technologies to
    Incineration
   C. Current Mercury Treatment Companies
   D. Request for Comment
 X, Possible Revisions to the Mercury LDRs
   A. Purpose of ANPRM
   B. Schedule
   C. Impact on Small Businesses
   D. Impact on State Programs
   XI. Administrative Requirements
   A, Regulatory Flexibility Act
   B. Executive Order 13045

 I. Introduction

   With this document, the Agency
 marks the beginning of a comprehensive
 review of existing RCRA waste
 treatment regulations applicable to
 mercury-bearing wastes and of our effort
 to revise, if necessary and appropriate,
 these regulations to improve treatment
 and land disposal methods. We decided
 to publish an ANPRM at this time
 because we expect to benefit
 significantly from early  public input on
 mercury waste generation and
 treatment, including information on
 alternative treatment technologies and
 on source reduction opportunities. The
 nature and extent of amendments to the
 mercury treatment standards have not
yet been determined. Any potential
revisions will ultimately be based on the
comments we receive on this ANPRM,
as well as data obtained  from other
sources (e.g., ongoing treatability
studies). As warranted, a proposal to
amend the current regulations will
appear in a future Federal Register
document.
                    A. Agency's Concern for Mercury
                      As evidenced by EPA's Mercury
                    Study Report to Congress2, mercury is
                    an element that the Agency has studied
                    quite extensively in recent years.
                    Moreover, a recent Agency Federal
                    Register notice identified mercury as
                    one of the "53 persistent,
                    bioaccumulative, and toxic (PBT)
                    chemicals and chemical categories
                    which may be found in hazardous
                    wastes regulated under RCRA" (63 FR
                    60332, November 9, 1998). In addition,
                    the EPA Action Plan for Mercury3 lists
                    this ANPRM as one of the twelve "most
                    significant actions that EPA is
                    undertaking to deal with the problem of
                    mercury exposure."
                      This ANPRM deals with a small
                    aspect of the overall mercury problem,
                    this being the treatment and disposal of
                    mercury-bearing  hazardous wastes.
                    Nevertheless, the potential problems
                    that exist in this area are significant, as
                    mercury can both leach out of
                    hazardous wastes and also be emitted
                    from the various  treatment processes.

                    B. Key Issues Addressed in the ANPRM
                      This ANPRM focuses on several key
                    issues with the current LDR mercury
                    treatment standards:
                      Incineration—We are interested in
                    pursuing further the issue of mercury air
                    emissions from incineration units. One
                    of the original premises behind the
                    current mercury treatment regulations
                    was that incineration would be a
                    pretreatment step to mercury recovery,
                    but this premise should be re-examined
                    at this point, given new information
                    about incineration of mercury wastes as
                    well as the upcoming Hazardous Waste
                    Combustion rule. Also, we currently
                    allow high mercury, low organic wastes
                    to be  incinerated, but alternative
                    treatment technologies may be
                    preferable for these wastes. We want to
                    investigate the impacts of reducing the
                    number of waste types allowed or
                    required to be incinerated (e.g.,
                    potentially only allow high organic, low
                    mercury  wastes, or organomercury
                    wastes).
                     Retorting—From comments on this
                    ANPRM, we hope to get a better idea of
                    the full environmental Impact of our
                   waste treatment standards. Our
                   treatment standards requiring recovery
                   of mercury via retorting are a case in
                   point. For example, air emissions and
                   the disposal of the residues from
                     2 "Mercury Study Report to Congress," Volumes
                   I-Vra. EPA-452/R-97-003, December 1997.
                     3 EPA Action Plan for Mercury (Attachment 1 to
                   "An Agency-wide Multi-media Strategy for Priority
                   PBT Pollutants") can be found at www.epa.gov/
                   opptlntr/pbt/pbtstrat.htm.
 secondary production (i.e., recycling-
 oriented processes) ought to be weighed
 against the diminishing benefits of
 recovery when such secondary
 production exceeds demand for the
 recycled product. In some cases, direct
 treatment for disposal could have some
 environmental advantages in certain
 supply-demand situations that have not
 previously been fully appreciated. We
 also want to investigate whether
 retorting (i.e., thermal recovery) is
 currently required for wastes that  are
 either not amenable to or are
 inappropriate for (e.g., mixed wastes)
 this treatment. Finally, although several
 factors suggest that retorting emissions
 are not significant, we still want to
 determine if there are data that support
 this suggestion.
   Source Reduction Options—EPA
 developed the current treatment
 regulations under statutory deadlines
 that impeded the exploration of
 potential source reduction technologies
 that could reduce or eliminate the
 generation of mercury-bearing wastes
 from many sources. The ANPRM
 contains a discussion of this
 investigation and potential options that
 might provide additional incentives for
 decreasing the amount of mercury in
 hazardous waste.

 II. Background

 A. Mercury in the Environment
   Control of the environmental risks
 posed by mercury is a complex problem
 for a number of reasons. First, mercury
 and its compounds are mobile in the
 environment. Elemental mercury is
 volatile under both ambient and
 combustion temperatures and is
 released into the environment mostly
 through air emissions from commercial
 and industrial sources. It can remain in
 the atmosphere for up to one year,  and
 hence can be widely dispersed and
 transported thousands of miles from the
 source of the emissions. When in the
 form of mercury salts, mercury air
 emissions are deposited more locally.
  Second, multiple pathways exist for
 exposure. The risks associated with
 various exposure pathways depend
 strongly on the chemical form (i.e.,
 species) of mercury involved. After
 deposition from the atmosphere,
 mercury can be methylated (especially
 in water bodies) to form the more toxic
 and bioaccumulative methylmercury.
 Exposure to levels of methylmercury
 found in fish taken from polluted water
 bodies has been associated with
neurological and developmental defects
in humans, with the developing fetus
most at risk. To reduce the risks of
exposure to methylmercury over time,

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                   Federal Register /Vol.  64, No.  103/Friday,  May 28, 1999/Proposed  Rules
                                                                      28951
 cost-effective strategies are needed both
 domestically and internationally to
 minimize the generation of mercury-
 bearing hazardous wastes.
   Some evidence suggests that, because
 mercury is a persistent,
 bioaccumulative, and toxic (PBT)
 substance, small releases may contribute
 to the build up of mercury  in the
 environment, especially the aquatic
 environment, over time, which may
 increase the potential for environmental
 and human health impacts.
 Consequently, EPA is looking at
 whether we may need to change the
 LDR mercury treatment standards.
 B. The Resource Conservation and
 Recovery Act
  One objective of the Resource
 Conservation and Recovery Act
 (RCRA)—the major hazardous waste
 statute—is to minimize the  generation of
 hazardous waste and the land disposal
 of hazardous waste by encouraging
 process substitution, materials recovery,
 properly conducted recycling and reuse,
 and treatment (see RCRA section 1003).
 To further this objective,  the Agency has
 set as goals of its Waste Minimization
 National Plan (WMNP) •» to:
  •  Reduce, as  a nation, the presence of
 the most persistent, bioaccumulative,
 and toxic (PBT) chemicals in RCRA
 hazardous wastes 10 percent by the year
 2000, and at least 50 percent by the year
 2005 (from a  1991 baseline);
  •  Promote  source reduction (and
 recycling where RCRA PBT chemicals
 cannot be reduced at the source) over
 treatment and disposal technologies;
 and
  •  Avoid the transfer of RCRA PBT
 chemicals across environmental media.
  Consistent with the goals  of RCRA
 and  the WMNP, the Agency seeks to
 reduce the generation of hazardous
 wastes containing mercury.  When this is
 not feasible, the Agency wants to look
 carefully at other opportunities to
 improve the recycling and treatment of
 residual mercury-bearing waste to
further reduce air emissions, the
 mobility of mercury species at the time
of disposal, and the potential for future
biological or chemical conversion to
other mobile and bioaccumulative
species of mercury.
 4 Waste Minimization National Plan, USEPA,
1994. EPA530-R-94-045.
 C. Mercury Treatment Standards
   EPA established treatment standards
 for mercury-bearing wastes as part of
 two rulemaltirigs. The LDjR First Third
 final rule (53 FR 31166', August 17,
 1988) established standards for RCRA
 hazardous waste code K071 (brine
 purification muds from the mercury cell
 process in chlorine production, where
 separately prepurified brine is not
 used), and the LDR Third Third final
 rule (55 FR 22569, June 1, 1990)
 established standards for five additional
 RCRA mercury-bearing waste codes:
 D009, characteristic mercury wastes; ,
 K106, wastewater treatment sludge from
 the mercury cell process in chlorine
 production; P065, mercury fulminate
 wastes; P092, phenyl mercuric acetate
 wastes; and Ul51, miscellaneous
 mercury wastes.
   For all of these wastes, EPA
 established two treatment subcategories:
 a high mercury subcategory, which
 includes wastes with a total mercury
 concentration greater than or equal to
 260 mg/kg; and a low mercury
 subcategory, which includes wastes
 with a total mercury concentration less
 than 260 mg/kg.
   • High mercury wastes are required to
 be roasted or retorted ("RMERC"), or
 incinerated ("IMERC") if organics are
 present. RMERC residues must then
 meet a numerical treatment standard of
 0.20 mg/L prior to land disposal, as
 measured by the toxicity characteristic
 leaching procedure (TCLP). IMERC
 residues must meet a numerical
 treatment standard of 0.025 mg/L TCLP.
  • Low mercury wastes are not subject
 to a specific technology for  treatment
 but must meet a numerical treatment
 standard of 0.025 mg/L TCLP.

 III. Mercury Hazardous Waste
 Generation and Management

 A. Industries Generating Mercury-
 Bearing Wastes
  Industrial use of mercury in the U.S.
 has been on the decline in recent years.
 Also, mercury is  no longer produced
 from mercury ore in the United States,
 as the last mercury ore mine closed in
 1990. However, mercury is still
produced as a byproduct from the
mining of gold ores and from secondary
production. Nearly all of the mercury
used in the United States is  derived
from secondary sources. Common
 secondary sources include spent
 batteries, chlor-alkali wastewater
 sludges, mercury vapor and fluorescent
 lamps, dental amalgams, electrical
 apparatus, and measuring instruments.
 The secondary producers typically use
 high-temperature roasting and retorting
 to recover mercury from the materials
 and distillation to purify contaminated
 liquid mercury metal.
   Data on estimated industrial demand
 for mercury show a general decline in
 domestic mercury use since demand
 peaked in 1964. Table 1 describes the
 mercury production and consumption
 in the U.S. for 1990-1997. In 1997, 346
 metric tons of mercury were used in
 industrial processes, 389 metric tons
 were produced by secondary mercury
 producers (i.e., producers recovering
 mercury from waste products), 134
 metric tons were exported, and 164
 metric tons were imported. These
 figures continued the trend since 1995
 of secondary production exceeding
 industrial consumption.5 Domestic
 demand fell by more than 75% between
 1988 (1503 metric tons) and 1997 (346
 metric tons). Much of this decline can
 be attributed to the elimination of
 .mercury as a paint additive and the    *
 reduction of-mercury in batteries. Other
 reasons for the reduction include the
 military phase-out of mercury fulminate
 as a primer in military explosives and
 the decline in the number of chlor-alkali
 facilities using the mercury cell method
 of chlorine production. Use of mercury
 by other source categories remained
 essentially the same between  1988 and
 1996.6 The data suggest that industrial
 manufacturers who use mercury are
 shifting away from its use except where
 mercury is considered essential.
 However, mercury consumption in the
 categories of Electrical and Electronic
 Uses and Instruments and Related
 Products is still growing, and is
 expected to continue to grow due to the
 increase in the manufacture of
 computers and other electrical
 equipment.7
  s Robert G. Reese, Jr. US Geological Survey,
Minerals Information, 1997.
  6 Mercury Study Report to Congress. USEPA,
December 1997, Volume I: Executive Summary,
page 3-8.
  7 The Status of Mercury in the United States. Draft
2, September 10, 1996, page A3-6.

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 28952
Federal Register/Vol.  64, No.  103/Friday,  May 28,  1999/Proposed  Rules
                                  TABLE 1.—MERCURY PRODUCTION AND USE STATISTICS
                                                        [Metric tons]

Mine Production:
— Principal product1 	
— Byproduct from gold mines 	
Secondary Production:
— Industrial , 	
— Government2 	
Imports for Consumption 	
Exports 	 	 	
Shipments from National Defense Stockpile3
Industry Stocks, year-end4 	
Industrial Consumption (reported) 	
Price, average dollars per flask:
D.F. Goldsmith 	
Free market 	
1990
448
114
108
193
15
311
52
197
720
$249.22
NA
1991

58
165
215
56
786
103
313
554
$122.42
NA
1992

64
176
103
92
977
267
436
621
$201 .39
NA
1993

W
350

40
389
543
384
558
$186.51
NA
1994

W
446

129
316
86
469
483
$194.45
NA
1995

W
534

377
179

321
436
$247.40
NA
1996

W
446

340
45

446
372
$261 .65
NA
1997

W
389

164
134

203
346
NA
$159.52
1998E

W
400

200
150

200
400
NA
$180
   Source: Robert G. Reese, Jr, US Geological Survey, Minerals Information, 1997, 1999.
   E—Estimated. W—withheld for confidentiality. NA—Not available
   1 Comprises only mercury produced at McDermitt Mine, as reported in Placer Dome Inc. Annual and 10-K reports. The mine was closed in No-
 vember 1990.
   2 Secondary mercury shipped from U.S. Department of Energy stocks.
   3 Shipments from the government stockpile were suspended in 1995.
   4 Stocks at consumers and dealers only. Mine stocks withheld to avoid disclosing proprietary data.
   Table 2 presents estimates of mercury
 emissions from the EPA Mercury Study
 Report to Congress (USEPA. December
 1997), and national emission estimates
 for hazardous waste combustors for
^1990, 1994, and 1997. The Report to
"Congress identifies combustion sources,
 Including utility and commercial/
                     industrial boilers, as the major source of
                     mercury emissions. Hazardous waste
                     combustion emissions and emissions
                     from secondary mercury production are
                     estimated to be less than five percent of
                     overall mercury emissions. In 1990 and
                     1994, mercury emissions from
                     hazardous waste combustion sources
 totaled approximately 6.4 metric tons
 per year, and for 1997, these emissions
 decreased to approximately 6.0 metric
 tons per year.8 Table 2 shows a further
 breakdown of the mercury emissions
 contribution from each hazardous waste
 combustor category.
                                    TABLE 2.—AVAILABLE MERCURY EMISSIONS DATA
                                                       [Metric Tons]

Area sources 	
Combustion sources 	
Manufacturing sources 	
Miscellaneous sources 	 '. 	

Total Air emissions 	 .- 	

-HW Cement Kilns 	 	 	
-HW Incinerators 	 	
— HW Lightweight Aggregate Kilns 	 	 	

Total HW Combustors  (% of total emissions) 	 '. 	

Secondary Hg Production'0' (% of total emissions) 	

1990<">





213

a
.9
13

6*

07

1994">)
.13
1252
14.4
.3

144

27
3.5
03

6.4
(4.4)
04
(0.3)
1997W







1 5
44
0 05

6 0



  •Source Category Listing for Section 112(d)(2) Rulemaking Pursuant to Section 112(c)(6) Requirements, USEPA, April 10, 1998;  63 FR
17338, Table 1.
  b Mercury Study Report to Congress, USEPA, December 1997, Volume I: Executive Summary, page 3-6.
  eNote to Laura McKelvey, USEPA, from Frank Behan, USEPA, dated July 1, 1998. This emissions inventory supports the rulemaking to revise
the technical standards for hazardous waste combustion facilities and will be included in a technical support document for that rule.
  ••Tola! HW Combustor emissions (6.4 metric tons) are a subcategory of the Combustion source emissions (125.2 metric tons) that appear in
ihe Mercury Study Report to Congress (see note "b above).
  •Secondary Hg Production emissions (0.4 metric tons) are a subcategory of the Manufacturing source emissions (14.4 metric tons) that appear
In the Mercury Study Report to Congress (see note "b" above).
  •When Interpreting any apparent data trends in
Table 2. you should note that differences in
emissions estimates are due to a combination of
                    factors Including actual data from performance in
                    the field, revisions to our estimation methodology,
                    and changes in the number of facilities operating
within each category. See documents noted as
sources for Table 2.

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                   Federal Register/Vol.  64.  No. 103/Friday, May 28, 1999/Proposed Rules
                                                                     28953
 B. Generation of Mercury-Bearing
 Hazardous Wastes
   The background document "Analysis
 of Current Mercury Waste Generation
 and Treatment" in the docket for today's
 notice includes tables that break down
 the generation of mercury-bearing
 hazardous wastes by waste code, waste
 form, and SIC Code based on the
 National Biennial RCRA Hazardous
 Waste Report (BRS) database.9 While
 the BRS provides a general idea of how
 much hazardous waste is generated, the
 numbers can be misinterpreted. For
 example, the BRS does not provide
 mercury concentrations in the waste
 streams. Therefore, we do not have a
 good estimate for the total amount of
 mercury that is treated by non-
 combustion technologies in the United
 States.
   Another interpretive issue with BRS
 data is that some waste quantities can be
 overestimates of the actual amount of
 waste produced. For example, some
 waste streams may be given multiple
 waste codes, one code being the specific
 waste code (e.g., K071), and another
 code being the general characteristic
 code (e.g., D009). This leads to an
 overestimate of the actual quantity
 generated.
   According to the 1995 BRS,
 approximately 12.2 million metric tons
 of mercury-bearing hazardous waste
 (wastewater and nonwastewater) were
 generated. This represents an increase
 from the 1993 BRS estimate of 11.5
 million metric tons. The National
 Hazardous Waste Constituent Survey
 (NHWCS), w,hich was designed to
 correspond with 1993 BRS data,
 estimated that almost 19 million metric
 tons of mercury-bearing wastes were
 managed. This NHWCS was created by
 EPA's  Office of Solid Waste in 1996 and
 distributed to over 200 of the largest
 generators and managers of hazardous
 industrial process wastes in the U.S.
 These  facilities account for over 90
 percent of the  total waste quantity in the
 hazardous waste universe as reported in
 the 1993 BRS.
  The  NHWCS also included estimates
 of the total amount of mercury managed
 by treatment technologies. The three
 technologies that were listed, and their
 respective mercury quantities, were
 "other treatment," 3257 metric tons;
 "aqueous inorganic treatment," 33
 metric tons; and "landfill," 30 metric
 tons. In the "other treatment" category,
 one facility (DOE/WRSC Savannah
 River)  accounts for approximately 98
 percent of the total constituent quantity.
 Without this facility, the.constituent
 total for "other treatment" would be 5.6
 tons. Since the survey was voluntary
and limited to  the largest waste streams,
 it is likely that it did not Include many
retorters and incinerators of mercury
 (especially high subcategory mercury)
wastes.
  Table 3 presents data from the Toxics
Release Inventory (TRI) database. The

         TABLE 3.—TRI DATA
             [Metric Tons]
 TRI is an information source about toxic
 chemicals that are being used,
 manufactured, treated, transported, or
 released into the environment. A facility
 is required to submit a TRI report if it
 (1) has ten or more full-time employees,
 and (2) manufactures or processes over
 25,000 pounds of the approximately,600
 designated chemicals or 28 chemical
 categories specified in the regulations,
 or uses more than 10,000 pounds of any
 designated chemical or category, and (3)
 engages in certain manufacturing
 operations in the industry groups
 specified in the U.S. Government
 Standard Industrial Classification Codes
 (SIC) 20 through 39. Federal facilities
 also are required to report following an
 August 1995 Executive Order.
  EPA emphasizes that the BRS and
 NHWCS  data presented above and the
 emissions data in Table 3 are estimates
 that may overestimate generation. The
 Agency welcomes any information that
 may help to construct a more accurate
 picture of the current mercury waste
 universe. This would include current
 data on waste generation (types,
 quantities, and mercury concentrations
 in the wastes), current waste
 management practices,  problems and/or
constraints on treating or recovering
these wastes, as well as information on
any waste minimization activities that
may have been implemented to reduce
or eliminate waste generation.

TRI total production-related waste:
-Mercury 	 	 	 	 	
—Mercury compounds 	 	 	 	
-Mercury + Mercury compounds 	 	 	
TRI wastes to recycling:
-Mercury 	 : 	
—Mercury compounds . 	 	 	
Mercury + Mercury compounds 	
TRI mercury + mercury compounds:
Fugitive air emissions 	 	 	 	
Stack emissions 	 	 	
Surface water discharges 	
Underground injection 	
On-site land releases 	 	 	 	 	
Off-site disposal 	 	 	 t
On-site treatment 	
Transfers to energy recovery 	
Transfers to treatment 	 	
Transfers to POTWs 	 	
Other off-site transfers 	 ; 	
TRI total not recycled:
—Mercury
-Mercury compounds 	 	 	 	
1993






528
.•57
020
£B07
DB2
157
NA
0
(79
0.007
0
147
ff
1994
4075
557
463.2
3900
426
4326
4.43
1 87
0 15
0.003
061
176
5.02
0
1.75
0.007
0
182
13.2
1995
4596
706
530.2
4437
568
5005
485
255
0 15
0003
046
944
2 86
023
759
0011
010
17 8
95.7
1996
390 1
36 1
4262
375 4
21 9
397 3
5 51
2 24
0 25
0 004
024
11 7
1 87
0 23
6 55
0007
o
10-7
15.0
 9 BRS data can be found at www.epa.gov/
epaoswer/hazwaste/data/

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 28954
Federal Register/Vol.  64, No.  103/Friday,  May 28,  1999/Proposed Rules
  "totals may not add due to rounding
                                           TABLE 3.—TRI DATA—Continued
                                                     [Metric Tons]

-Marcurv + mercurv comoounds" 	
1993
24.4
1994
31.4
1995
113.5
1996
28.6
 IV. Current RCRA Regulations
 Governing Treatment of Mercury-
 Bearing Hazardous Wastes
 A. RCRA  Waste Code Classification and
 Treatment
   EPA's hazardous waste classification
 system identifies six categories of
 mercury-bearing wastes, each of which
 has a separate RCRA waste code.
   The following is a detailed
 description of the six mercury waste
 codes:
   D009 Wastes—Characteristic Mercury
 Wastes. D009 wastes are extremely
 variable in composition, and depend on
 the industry and process that generate
 the waste. Some of the more common
 types of D009 wastes include
 miscellaneous wastes from chlor-alkali
 production facilities (especially cell
 room trench sludge and activated
 carbon for liquid or gas purification),
 used fluorescent lamps, batteries,
 switches,  and thermometers. D009
 wastes are also generated in the
 production of organomercury
 compounds for fungiclde/bactericide
 and pharmaceutical uses, and during
 organic chemicals manufacturing where
 mercuric chloride catalyst is used.10
   Mercury concentrations within D009
 wastes may range from 0.20 mg/L TCLP
 to greater than 75 percent of the total
 waste composition. D009 wastes may
 also contain organic compounds,
 usually when mixed with solvent
 wastes.
   Although characterization data for
 D009 wastes are limited, some
 conclusions can be made regarding
 potential treatment concerns. Wastes
 with greater than 500 ppm 40 CFR part
 261, appendix VTJI organics (such as
 benzene) may be problematic for
 commercial retorting facilities due to
 the permitting requirements for boiler
 and industrial furnaces (BIF) (40 CFR
 266.100(c)). At least two facilities are
 unable to handle wastes with these
 levels of volatile organics due to the
 additional permitting that would be
 required. However, these two facilities
 are capable of treating non-volatile
 activated carbons.
                      K071 Wastes—Brine purification
                    muds from the mercury cell process in
                    chlorine production, where separately
                    prepurified brine is not used. K071
                    wastes are generated by the chlor-alkali
                    industry in the mercury cell process. In
                    this process, sodium chloride is
                    dissolved to form a saturated brine
                    solution. The brine solution is purified
                    by precipitation, using hydroxides,
                    carbonates, or sulfates. The precipitate
                    is dewatered to form K071 wastes, while
                    the purified brine continues in the
                    process. The depleted solution from the
                    mercury cell is ultimately recycled to
                    the initial step of the process.
                      Available analytical information for
                    K071 brine purification muds show that
                    these-wastes consist primarily of
                    inorganic solids and water. The normal
                    total mercury content of K071 wastes is
                    less than 100 parts  per million (ppm)
                    and is normally characterized as
                    metallic mercury or soluble mercuric
                    chloride." Mercury from  K071 wastes is
                    typically recovered using a wet process,
                    reflecting the BOAT for this waste.
                      K106 Wastes—Wastewater treatment
                    sludge from the mercury cell process in
                    chlorine production. Like K071 wastes,
                    K106 wastes are generated from chlorine
                    production using the mercury cell
                    process. Effluent from the mercury cell
                    includes spent brine, a portion of which
                    is recycled and a portion of which is
                    purged to wastewater treatment. Other
                    plant area wastewaters (e.g., stormwater,
                    washdown waters)  are also typically
                    sent to this treatment system. The
                    wastewater treatment process generates
                    a sludge through precipitation and
                    filtering, which is K106 waste. Sulfides
                    (as either sodium sulfide,  Na2S, and/or
                    sodium bisulfide, NaHS) have been
                    commonly used as  a precipitation agent
                    for at least the last 10 years (1988 to
                    1998), according  to data from the
                    Chlorine Institute. Sludges generated in
                    this manner are comprised, in part, of
                    mercuric sulfide. Other-(minor)
                    precipitation agents result in the
                    formation of mercury hydroxide or in
                    elemental mercury. However, sulfide
                    precipitation is preferable to hydroxide
                    precipitation using  hydrazine because
                    mercury hydroxide  is susceptible to
 matrix dissolution over a wide range of
 pH under oxidizing conditions.
   Available analytical information for
 K106 wastes indicates they are
 primarily composed of water and
 diatomaceous earth filter aid. This is
 true for K106 wastes generated by both
 sulfide treatment and hydrazine
 treatment. K106 wastes from sulfide
 precipitation contain approximately 4.4
 percent mercury, as mercuric sulfide,
 while K106 wastes from hydrazine
 treatment contain approximately 0.5
 percent mercury, as mercurous
 hydroxide.12
   The mercury concentration in K106
 waste is consistently greater than 260
 mg/kg and therefore retorting is a
 required technology for this waste. K106
 waste also contains significant levels of
 sulfides/sulfates, sodium chloride, and
 organics,  although the mercury is likely
 in an elemental or a sulfide form.
   P065 Wastes—Mercury fulminate.
 P065 wastes consist of discarded
 mercury fulminate product, off-
 specification mercury fulminate
 product, and container or spill residues
 thereof. No waste characterization data
 were available for P065 listed wastes.
 The quantity of P065 waste is expected
 to have declined, as the military has
 phased out its use in explosives.13
   P092 Wastes—Phenylmercury acetate.
 P092 wastes consist of discarded
 phenylmercury acetate product, off-
 specification phenylmercury acetate
 product, and container or spill residues
 thereof. There are very little data
 available on the composition of P092
 listed wastes. The primary constituent
 of P092 listed wastes is phenylmercury
 acetate; organic constituents (in
 particular, benzene) are also expected to
 be present.14 The use of phenylmercury
 acetate as a preservative in  latex paint
 was phased out in 1991. Thus, the
 quantity of P092 waste is expected to
 decline dramatically as the  stock of
 mercury-bearing paint is depleted.15
  1° U.S. EPA, Best Demonstrated Available
Technology (BOAT) Background Document for
Mercury Wastes. Nov 1989. page 2-18.
                     11 U.S. EPA, BOAT Document for Mercury
                   Wastes, November 1989, page 2-11.
  12 U.S. EPA, BOAT Document for Mercury
Wastes, November 1989. page 2-11.
  13 Mercury Treatment and Storage Options
Summary Report, A.T. Kearney report for USEPA
Reg 5, May 1997, page 1.
  14 U.S. EPA, BDAT Document for Mercury
Wastes, November 1989, page 2-17.
  15 Mercury Treatment and Storage Options
Summary Report, A.T. Kearney report for USEPA
Reg 5, May 1997, page 1.

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                    Federal Register/Vol. 64, No. 103/Friday,  May 28,  1999/Proposed Rules
                                                                        28955
   U151 Wastes—Mercury. U151 wastes
 consist of discarded elemental mercury
 product, off-specification metallic
 mercury product, and container or spill
 residues thereof. The majority of U151
 wastes reported as a single waste code
 (i.e., not mixed with other listed or
 characteristic wastes) in the EPA 1986
 Generator Survey are ovei;50 percent
 mercury. Trig-principal constituent of
 U151 is metallic mercury.16
 B. Existing LDR Regulations for
 Mercury-Bearing Wastes

   Table 4 summarizes the current LDR
 requirements for these wastes.
                       TABLE 4.—LDR REGULATIONS FOR MERCURY-BEARING NONWASTEWATERS
             Mercury Subcategory Description
                                                        LDR treatment requirements
                                                      Concentration in mg/l TCLP; or
                                                            Technology code
                                          Applicable
                                            waste
                                            codes
               Federal Register publication
 High Mercury-Organic Subcategory (i.e., the waste has a total
  mercury content greater than or equal to 260 mg/kg), con-
  tains organics, and is not an incinerator residue.
 Mercury fulminate waste regardless of  total mercury content
  and is not an incinerator or RMERC residue.
 Phenylmercury acetate waste regardless of total mercury con-
  tent and is not an incinerator or RMERC residue.
 High Mercury-Inorganic Subcategory (i.e., the waste has a total
  mercury content greater than or equal to  260 mg/kg), and is
  inorganic, including residues from incineration; roasting and
  retorting.
 Low Mercury Subcategory (i.e., the waste has a total mercury
  content less than 260 mg/kg), and that are residues from
  RMERC only.
 Low Mercury Subcategory (i.e., the waste has a total mercury
  content less  than 260 mg/kg),  and are not residues  from
  RMERC.
 Elemental mercury contaminated with radioactive materials ......

 Hydraulic oil contaminated with Mercury Radioactive Materials
  Subcategory.
               Incineration   (IMERC);    OR
                Roasting    or    Retorting
                (RMERC).
               IMERC	
               IMERC; OR RMERC .

               RMERC 	
              0.20 mg/l TCLP
              0.025 mg/l TCLP
              AMLGM

              IMERC ..
  D009
  P092

  P065

  P092

  D009
  K106
  U151

  D009«»
  K071
  K106
  P065
  P092
  U151
  D009«»
  K071
  K106
  P065
  P092
  D009
  U151
  D009
 55 FR 22569,
 (June 1. 1990).

 55 FR 22569,
 (June 1, 1990).
 55 FR 22569,
 (June 1, 1990).
 55 FR 22569,
 (June 1, 1990).
 55 FR 22569,
 (June 1, 1990).
 D009 treatment standard re-
  vised 63 FR 28568,
 (May 26, 1998).

 55 FR 22569,
 (June 1, 1990).
 D009 treatment standard re-
  vised 63 FR 28568, (May 26,
  1998).
•55 FR 22569,
 (June 1, 1990).
 55 FR 22569,
 (Junel, 1990).
  "D009 wastes with concentration-based standards, rather-than specified technology standards, must also meet §268.48 standards (LDR
Phase IV final rule, May 26, 1998).
V. Mercury Treatment Technologies-
Roasting and Retorting of Mercury
Wastes

A. Process and Regulation

  Roasting or retorting _of mercury .
(RMERC) and subsequently condensing
the volatilized mercury for recovery is
currently required for D009, K106, and
U151 wastes in the high mercury-
inorganic Subcategory (i.e., 260 mg/kg
total mercury and above), and P065 and
P092 nonwastewaters that are
incinerator residues or residues from
roasting or retorting that still contain
greater than 260 mg/kg total mercury.
RMERC is also a treatment option for
D009 wastes in the high mercury-
organic Subcategory that are not
incinerator residues, and P092 wastes
that are not incinerator or RMERC
residues.
  Most retort processes use a batch
vessel. The mercury-bearing waste is
sealed in the vessel and volatile gases,
such as mercury vapor, are released
when the vessel is heated (sometimes
under vacuum conditions). The mercury
vapor is condensed, collected, and
subsequently purified by successive
distillation. The BOAT Background
DocumentI7 also describes roasting,
where air is introduced to the hot waste
to oxidize mercury compounds and to
help transport mercury vapor to the
condenser.
  All wastewater and nonwastewater
treatment residues derived from the
RMERC process must meet various
standards that ensure proper mercury
removal via RMERC. If treatment
residues are still in the high mercury
Subcategory (i.e., contain 260 mg/kg
total mercury or more), they must be
retreated. If the RMERC treatment
residues are in the low mercury
Subcategory (i.e., contain less than 260
mg/kg total mercury), they must meet a
standard of 0.20 mg/L TCLP mercury
prior to being land disposed. (Note: low
mercury Subcategory wastes that are not
residues of RMERC must meet a more
stringent standard of 0.025 mg/L TCLP
mercury.) Thus, current LDR regulations
mandate recovery (and therefore
recycling) of mercury waste that
contains greater than or equal to 260
mg/kg total mercury; impose  regulatory
control over the emissions from roasting
and retorting and the disposal of
residues derived from the process; and
differentiate between the residues from
RMERC versus other treatment
processes to encourage recycling and
recovery. The Agency requests comment
on whether RMERC should include
types of recycling technologies other
than roasting or retorting, which also
would allow treatment residues from
those technologies to be eligible for the
0.20 mg/L standard.
  '« U.S. EPA, BDAT Document for Mercury
Wastes, November 1989, page 2-17.
  " Final BDAT Background Document for
Mercury-Containing Wastes D009, K106, P065,
P092, and U151. USEPA, May 1990, page 3-2.

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 28956
Federal Register/Vol. 64, No.  103/Friday, May  28,  1999/Proposed  Rules
 B. Air Emissions from Roasting and
 Retorting
   Air emissions from a mercury
 retorting or roasting unit (or facility)
 also are regulated. The unit or facility
 must be subject to one or more of the
 following (40 CFR 268.42):
   (a) A National Emissions Standard for
 Hazardous Air Pollutants (NESHAP) for
 mercury;
   (b) A Best Available Control
 Technology (BACT) or Lowest
 Achievable Emission Rate (LAER)
 standard for mercury imposed pursuant
 to a Prevention of Significant
 Deterioration (PSD) permit; or
   (c) A state permit that establishes
 emission limitations (within meaning of
 section 302 of the Clean Air Act)  for
 mercury.
   Secondary mercury production is
 estimated to have accounted for
 approximately 0.4 Metric tons of
 mercury emissions in 1995.18 Air
 emissions from retorting or roasting
 units are generally scrubbed and  passed
 through carbon filters that efficiently
 capture mercury vapor. When spent.
 these filters are retorted or roasted along
 with other wastes to recover the
 mercury that has been trapped. The
 units may also incorporate an
 afterburner prior to any additional air
 pollution control devices (APCDs) for
 odor control.
 (a) Chlor-alkali facilities
   Of the 14  chlor-alkali facilities using
 the mercury cell process, six conduct
 onsite retorting or roasting. The
 background document "Waste Specific
 Evaluation of RMERC Treatment
 Standard" presents air emissions  data
 for these six facilities from the TRI. and
 for two other facilities that do not
 conduct onsite mercury recovery. These
 two facilities ship their wastes off-site to
 other facilities owned by the same
 parent company. The releases shown
 represent all releases, including
 retorting emissions, fugitive emissions
 and emissions from hydrogen stream
 purification.19 The airborne mercury
 releases from all facilities with a retort
 process unit range from 250 to 1,500
 pounds for 1995. However, mercury
 releases from facilities without a retort
 process unit are comparable to the
 releases from facilities with retorters,
 indicating that retort emissions are
 relatively small compared to total
 facility emissions.
                     (b) Commercial Facilities
                       The background document "Waste
                     Specific Evaluation of RMERC
                     Treatment Standard" contains data on
                     mercury emissions to air, water, and
                     offsite recycling sites for the three
                     commercial roasting or retorting
                     facilities that submitted TRI reports. No
                     other emissions information is available
                     for other facilities.
                       Air emissions data for the three
                     facilities indicate that releases are low.
                     Stack emissions data were not obtained,
                     but verbal correspondence indicates that
                     measured emissions are also low. For
                     example, one facility measures for
                     mercury at the stack several times per
                     day. A State official believed that these
                     measurements are normally non-detects
                    and, if any mercury is detected, the
                    operation shuts down.20
                      Detailed air pollution control device
                    information is also available for several
                    facilities. Air pollution control at
                    several of the commercial roasting/
                    retorting facilities includes carbon
                    adsorption with no scrubbers.21 BRS
                    data indicate that at least one facility
                    uses carbon absorption and a scrubber.
                    Literature reviews and discussions with
                    technology vendors indicate that the use
                    of activated carbon beds can achieve
                    90% or more mercury removal, with
                    some greater than 99%.22
                      At one facility, all retorting and
                    ancillary operations (e.g., material
                    handling)  are conducted indoors.23 This
                    facility has'emission controls for its
                    furnace operation and for the building
                    where the ancillary operations are
                    conducted. The furnace off gas is
                    cooled, then passed through activated
                    carbon and a gas afterburner. Vent gas
                    from the building passes through
                    activated carbon and is emitted to the
                    atmosphere. A second facility's furnace
                    emissions  are cooled, passed through a
                    series of activated carbon absorption,
                    and emitted to the atmosphere.24 A
                    third company's retort process is
                    contained  in a multicompartment
                    building and all of the operations are
                    conducted under negative pressure to
                    help control emissions. The facility also
                    uses sealed rooms for the preheating
                    and cooling of the mercury-bearing
                    wastes, and the rooms are equipped
  '» Mercury Study Report to Congress, USEPA,
December 1997, Volume I: Executive Summary.
page 3-6.
  "Telephone conversation, Illam Rosarlo. U.S.
EPA. and John Vlerow. SAIC. July 1998.
                     ^Telephone Conversation between John Vierow,
                   SAIC, and Luis Pizarro, USEPA Region 3, June
                   1998.
                     21 Ibid.
                     22 Draft Technical Support Document for HWC
                   MACT Standards, USEPA, February 1996, F-96-
                   RCSP-S0047.
                     23 Bethlehem Apparatus, Waste Analysis and
                   Recycling Plan, 1996.
                     24 Telephone Conversation between John Vierow,
                   SAIC. and Luis Pizarro, USEPA Region 3, June
                   1998.
 with their own carbon adsorption filters
 to trap mercury vapor.25
   The Agency requests additional data
 on air emissions from roasting and
 retorting units, including information
 detailing the effectiveness of existing
 after burner, carbon bed, and scrubber
 controls.
 C. Request for Comment
   The Agency specifically requests
 comment on the following:
 1. What Wastes Are Not Amenable to
 RMERC?
   Mercury recovery facilities are exempt
 from the boiler and industrial furnace
 requirements of 40 CFR part 266,
 subpart H provided they meet certain
 requirements, such as the rejection of
 wastes with greater than 500 ppmw of
 certain organic constituents (i.e., organic
 compounds on 40 CFR part 261,
 appendix VIII). However, these units
 may process wastes containing various
 plastics, which may require the thermal
 destruction of odor causing emissions
 resulting from the pyrolysis (i.e.,
 thermal decomposition) of these
 plastics. See appendix XIII of part 266.
 Other problem wastes for mercury
 recycling include:
   •  Wastes containing organic forms of
 mercury (e.g.', mercury fulminate,
 phenylmercury acetate). Independent of
 regulatory restrictions, some facilities
 do not accept any organomercury
 compounds because the compound does
 not decompose into elemental mercury.
 Instead, the compound is carried
 through the retort and distillation
 system and results in an impurity in the
 final mercury product.26
  •  Wastes with a high water content.
 Large quantities of generated steam
 interfere with the mercury condensation
 process. To solve this problem, one
 facility precipitates or concentrates
 liquid solutions prior to retorting.
  •  Wastes containing mercuric
 chloride, polyvinyl chloride, and
 halogens. Mercury chloride and other
 salts carry over during the retorting and
 condensation process, forming
 impurities.27 Additionally, in the
 presence of steam, halogens will form
 acids, which corrode equipment. One
 facility pre-treats corrosive solutions
 using ion-exchange to overcome this
 problem. Another company uses
chemical conversion to mercuric oxide
prior to retorting to  remove halides
before processing.
  25 Mercury Refining Company, Facility
Information Packet.
  28 Frederick J. Manley, USPCI Lab Pack Manager,
letter to EPA, July, 2, 1992.
  "Ibid

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                   Federal Register/Vol.  64,  No.  103/Friday,  May 28, 1999/Proposed  Rules
                                                                      28957
   • Wastes containing volatile metals.
Some retorting facilities restrict certain
metals, including lithium, arsenic, and
thallium. It is not known why these self-
imposed restrictions exist.
   • Radioactive wastes. For regulatory
and safety reasons, most facilities reject
radioactive wastes. Only one facility has
been identified that accepts radioactive
mercury-bearing wastes.
   • Mercury nitrate/nitrite solutions.
This material typically results in an
ignitable solution, which appears to
raise permit concerns for facilities28
   • Wastes containing mercuric sulfide.
These wastes are difficult to retort.
Additives are required to scavenge
elemental sulfur produced before it can
recombine  with the mercury.
   The Agency requests further
information detailing the problems that
occur when treating wastes in retorting
units, including the forms of mercury
wastes that are not technically amenable
to retorting and/or are not accepted at
retorting facilities.
2. Should Non-Thermal Recycling
Technologies Be Allowed for High
Mercury Wastes and, if so, Should They
Continue To Be Subject to a More
Stringent Residual Standard?
   Since the RMERC regulations were
promulgated, additional recycling
technologies have been developed. One
such technology is Universal Dynamic's
REMERC process. While this process
accomplishes mercury recycling in a
closed system that limits air emissions,
the residues are currently subject to the
more stringent 0.025 mg/L TCLP
mercury standard for non-RMERC
residues. The Agency requests comment
and data to determine whether non-
RMERC recycling processes, if properly
designed and operated, should continue
to be under more stringent regulation
because these processes may result in
less mercury recovery than roasting and
retorting processes, increased mercury
content of residuals, higher air
emissions, or a less stable final waste
form. If these alternative recycling
technologies are determined to be viable
and are demonstrated to be properly
designed and operated, the residuals
could be subject to the current RMERC
residual standard of 0.20 mg/L, or to a
new treatment standard that the
alternative technology has been
demonstrated to achieve. Alternatively,
the current regulations could be
expanded to include recycling
technologies other than RMERC  as
potential options for treating high
mercury subcategory wastes.
 3. Should the Mercury Concentration
 Requirement for RMERC (260 mg/kg or
 above) Be Adjusted?
   The Agerifiy requests data to support
 the potential adjustment of the 260 mg/
 kg total mercury distinction between the
 high and low mercury subcategories.
 The Agency requests data on difficult to
 treat wastes, particularly ones that have
 required one or more processings to
 achieve a total mercury concentration of
 less than 260 mg/kg, and on initial total
 mercury content and total mercury
 content after each treatment, together
 with the associated analytical quality,
 assurance measurements and operation
 and design parameters of the unit. The
 Agency reminds commenters submitting
 data in support of their views to include
 with the data evidence that appropriate
 quality assurance/quality control29
 (QA/QC) procedures were followed in
 generating the data. Data that the
 Agency cannot verify through QA/QC
 documentation may be given less
 consideration or disregarded in
 developing regulatory options for
 proposed and final rules. Also, it is
 important that commenters demonstrate
 their processes were optimized and
 under stable operation during the test
 period. The Agency also requests
 information from retorting facilities
 concerning the minimum, maximum,
 and average concentration levels of
 mercury wastes accepted at these
 facilities.
 4. Should the Agency Allow Alternative
 (Non-Recycling) Treatment Options to
 RMERC for High Mercury Wastes?
  The Agency requests comment on
 whether treatment options besides
 recovery should be permissible for high
 mercury subcategory wastes. Recycling
 mercury in industrial processes and
 using recycled mercury as a raw
 material for commercial products are
 potential sources of mercury releases
 into the environment. Because mercury
 releases to the environment have had
 adverse impacts on both human health
 and the environment, federal
 regulations have concentrated on
 controlling and, in some cases, phasing
 out mercury use in industry. At least in
 part, a result of these findings and
 actions has been a decline in the use of
 mercury in U.S. industry over the years.
  Therefore, the Agency seeks
 information on technologies that will
treat high mercury wastes into a safe
environmental form so that all mercury
  28 Ibid
  29 For guidance, see Final Best Demonstrated
Available Technology (BDAT) Background
Document for Quality Assurance/Quality Control
Procedures and Methodology: USEPA. October 23,
1991.
 release pathways into the environment
 are minimized. The Agency requests
 comment on whether alternative land
 disposal treatment technologies to
 recovery (e.g., sulfide conversion and
 stabilization with sulfur-polymer
 cement) for high mercury wastes should
 be made an option and requests data on
 mercury releases from wastes treated by
 these technologies. Data and
 information should also be included on
 the technology's ability to treat wastes
 containing organics, and the maximum
 organic level that the technology can
 handle.
   One waste form that deserves
 particular mention is waste containing
 mercuric sulfide. These wastes are
 difficult to retort efficiently, and
 additives are required to react with or
 otherwise bind the elemental sulfur to
 prevent its recombination with the
 elemental mercury being recovered. As
 an alternative, precipitation of mercury
 using sulfide is a technology commonly
 applied in wastewater treatment. The
 Agency requests comment and data  on
 whether such wastes should be either
 exempt from the RMERC requirement,
 subject to numerical standards, or
 subject to another technology standard.
 5. Can Emissions From Secondary
 Mercury Production Be Further
 Reduced?
   While the roasting/retorting processes
 effectively recycle mercury and have air
 emission controls, an estimated 0.4
 Metric tons/yr of air emissions from
 secondary mercury production still
 exists. The Agency requests comment
 on the feasibility of more efficient
 controls during secondary mercury
 production and on the use of enclosed
 treatment processes.
 6. Should EPA Consider Revising the
 Debris Standards To Require That High
 Mercury Subcategory Wastes That Also
 Meet the Definition of Debris Be
 Retorted?
  The debris standards for hazardous
 wastes are listed in Table 1 of 40 CFR
 268.45. EPA requests comment on
 potential revision of these standards to
 require the roasting or retorting of
 hazardous debris if the mercury
 concentration is greater than or equal to
 260 mg/kg total mercury. EPA dealt
 with a specific case of mercury debris in
 early 1997 involving Aid-to-Navigation
 (ATON) batteries, and the most
 appropriate treatment and disposal
 method. At that time, EPA stated that it
 is more appropriate to apply  the debris
standards than the non-debris standards
for mercury wastes, the latter of which
would require RMERC (if the wastes
contain 260 mg/kg or more total

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 28958
Federal  Register/Vol. 64, No. 103/Friday, May  28,  1999/Proposed Rules
 mercury). However, in subsequent
 discussions with members of the
 recycling industry, the Agency was
 informed that retorting is indeed
 feasible on these types of wastes. We are
 seeking comments on whether the
 debris standard should be revised to
 require RMERC if the waste is in the
 high mercury subcategory. Commenters
 are encouraged to also include the
 possible ramifications of such a
 revision.
 VI. Mercury Treatment Technologies—
 Incineration of Mercury Wastes
 A. Current Regulations
   Three categories of waste streams
 must or can be incinerated under the  •
 current LDR treatment standards. These
 three are: D009 high mercury-organic
 subcategory; P092 wastes regardless of
 total mercury content that are not
 incinerator residues or are not residues
 from RMERC; and P065 wastes
 regardless of the total mercury content
 that are not incinerator or RMERC
 residues. The current regulations
 specify that incineration  (IMERC) must
 be performed in units operated in
 accordance with the technical
 requirements of 40 CFR part 264,
 subpart O and 40 CFR part 265, subpart
 O.30 All wastewater and nonwastewater
 residues derived from this treatment
 process must then comply with the
 corresponding treatment standards per
 waste code, with consideration of any
 applicable subcategories.
 B. Characteristics of Mercury in
 Incinerators and Current Emission
 Control Systems
  Mercury is slightly volatile at ambient
 temperatures but is quite volatile at
 temperatures common to thermal
 treatment devices. It boils at
 approximately 356 degrees Celsius and
 typically escapes with other stack gases
 from incineration. With respect to
 mercury behavior in combustion
 systems and existing control techniques,
 mercury is volatilized and converted to
 elemental mercury in the high
 temperature regions of furnaces. As the
 flue gas is cooled, elemental mercury is
 oxidized to ionic forms. Elemental
 mercury, mercuric chloride, and
 mercuric oxide are all in the vapor
 phase at flue gas cleaning temperatures
 and special methods must be used for
 their capture. Each of these forms of
 mercury can be adsorbed  onto porous
solids such as fly ash, powdered
activated carbon, and calcium based
acid gas sorbents for subsequent
collection in a particulate matter  control
                    device. Only one hazardous waste
                    incinerator (WTI, Inc., East Liverpool,
                    Ohio) currently has this type of APCD
                    installed. Control of mercury in
                    municipal waste combustors has been
                    based on injection of powdered
                    activated carbon upstream of an
                    electrostatic precipitator or fabric filter,
                    and many municipal units have this
                    type of system installed.
                      Mercury compounds also can be
                    captured effectively using activated
                    carbon or other sorbents. Fixed bed,
                    fluidized bed, and duct injection
                    arrangements have all been
                    demonstrated to perform at 90% or   '
                    more mercury removal efficiency, with
                    some as high as 99% or greater. Systems
                    without carbon injection, i.e., wet
                    scrubbing systems designed for acid
                    gases like hydrochloric acid, have much
                    poorer mercury capture efficiency
                    ranging from 0 to 40%. The highest
                    control levels for activated carbon
                    systems are achieved by optimizing the
                    carbon type and the critical operating
                    parameters of the control system. For
                    example, for activated carbon injection,
                    these parameters would include carbon
                    feedrate, injection location, and
                    temperature.31
                    C. Amount of Mercury Emitted from
                    Incinerators and Other Hazardous
                    Waste Combustors
                     As part of our current MACT
                    rulemaking  to upgrade emission
                    standards for hazardous waste
                    incinerators and hazardous waste-
                    burning cement kilns and lightweight
                    aggregate kilns (collectively known as
                    hazardous waste combustors), the
                    Agency developed a 'database containing
                    detailed information on hazardous
                    waste emissions, including mercury.
                    The database also includes information
                    on the quantity of mercury in each
                    feedstream fed to the combustion unit.
                    These feedstreams include, if
                    applicable, the hazardous waste, coal
                    and other conventional fuels, and raw
                    materials.
                     Table 2, which is presented earlier in
                    this preamble, shows national emission
                    estimates for hazardous waste
                    combustors for  1990. 1994 and 1997. In
                    1990, mercury emissions from these
                   sources totaled approximately 6.4
                   metric tons per year. Table 2 shows a
                   further breakdown of the mercury
                   emissions contribution from each
                   hazardous waste combustor category.
                   For 1994, national emissions from
                   hazardous waste combustors were
                   estimated to be approximately 6.4
 metric tons per year. These sources are
 estimated to contribute approximately
 4.4 percent of the total anthropogenic,
 or man-made, emissions of mercury in
 the U.S. For 1997, mercury emissions
 from hazardous waste combustors total
 approximately 6.0 metric tons per year.
 In general, mercury emissions from
 hazardous waste combustors have
 decreased slightly between 1990 and
 1997.32

 D. General Waste Characterization Data
 on Mercury in Hazardous Waste
 Streams
   Treatment capacity determinations for
 the LDR program are generally made
 based upon the broader Biennial Report
 System database, which covers all types
 of hazardous waste activities. If we were
 to amend our LDR treatment standards
 in any respect, we would also consult
 this database. The 1995 Biennial Report
 indicates that for mercury-bearing
 wastes, 86,400 tons were incinerated
 and 380,000 tons were reused as fuel
 (i.e., sent to cement kilns and light
 weight aggregate kilns). However, the
 BRS system itself does not distinguish
 between the high and low mercury
 subcategories, nor does it show what
 concentration of mercury is present in
 these waste streams.
   D009 wastes are extremely variable in
 composition, and their characteristics
 depend on the industry and process that
 generate the waste. Mercury
 concentrations in D009 wastes can range
 from 0.2 ppm to greater than 75 percent
 of the total waste composition.
 Although characterization data for D009
 wastes are limited, some conclusions
 can be made regarding potential
 treatability issues. According to the
 1995 BRS, the three largest volumes of
 D009 waste by waste form were reported
 as "halogenated/nonhalogenated solvent
 mixture" (21,700 tons), "other
 halogenated solids" (8,400 tons),  and
 "concentrated sol vent-water solution"
 (4,700 tons). These waste form
 descriptions suggest that the mercury is
 not the primary contaminant in the
 wastes. Finally, because concentration
 data are not provided in the BRS, D009
 wastes could be comprised of both high
 and low mercury subcategory wastes.
   Certain D009 waste streams may be
 incinerated for reasons other than the
 LDR IMERC treatment requirement. For
 example, BRS waste streams containing
  M40 CFR 264 subpart 0 and 265 subpart O are
the regulations Tor hazardous waste Incinerators.
                    31 Draft Technical Support Document for HWC
                   MACT Standards, USEPA, February 1996, F-96-
                   RCSP-S0047.
  32 When interpreting any apparent data trends in
Table 2, you should note that differences in
emissions estimates are due to a combination of
factors including actual data from performance in
the field, revisions to our estimation methodology,
and changes in the number of facilities operating
within each category. See documents noted as
sources for Table 2.

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                    Federal Register/Vol. 64, No. 103/Friday, May 28,  1999/Proposed Rules
                                                                       28959
 hazardous materials, particularly
 dioxins and PCBs, as well as certain
 ignitables and reactives require
 incineration treatment. Incineration and
 other types of combustion are the only
 common  treatment methods that
 completely destroy dioxins and PCBs.
 Therefore, many of the waste streams
 reported to the 1995 BRS may have to
 be processed using incineration
 regardless of the mercury content. Many
 waste streams contain  D009 mercury
 organic-bearing wastes from lab packs,
 halogenated/nonhalogenated solvent
 mixtures, certain halogenated solids,
 oily sludges, and organic paints.
   No waste characterization data were
 found for P065 listed wastes. Two
 facilities in the 1995 BRS reported
 incineration of P065.
   Very  little data are available on the
 composition of P092 listed wastes. The
 primary constituent of P092 listed
 wastes is  phenylmercury acetate;
 organic constituents (in, particular,
 benzene)  are also expected to be present
 (USEPA 1989). Five facilities in the
 1995 BRS reported incineration of P092.
 E. EPA's Re-Evaluation of the MERC
 Standard
   As discussed earlier, the current LDR
 regulations require or allow incineration
 of three types  of waste  streams, most
 notably D009 wastes that contain
 mercury above 260 mg/kg and that also
 contain some organics  (i.e., the high
 mercury organic subcategory). The two
 original premises behind IMERC were
 that: (1) incineration would destroy the
 organic component or organomercury
 complexes in the waste stream, and the
 residues, if greater than 260 mg/kg total
 mercury, would be retorted to recover
 the mercury; and (2) applicable
 regulatory controls would provide
 adequate control of mercury air
 emissions.
   With  respect to the premise that
 mercury would be recovered from
 incineration systems, either incinerator
 bottom ash residues or  emission control
 residues (e.g., spent activated carbon,
 scrubber sludges) could be sent to
 mercury recovery units. Incinerator
 bottom ash is likely to contain little
 mercury, however, because mercury is
 easily volatilized to the combustion gas.
 In addition, incinerators generally are
 not equipped with emission control
 equipment that removes mercury from
 combustion gas. In fact, the latest BRS
 report shows no record of incinerator
 residuals going to mercury recovery
 units. As a practical matter, although
 incineration destroys the organics, it
does not make the mercury particularly
amenable  to recovery. It is therefore
difficult to regard incineration as
 contributing to the recovery of mercury,
 which was one of our original premises.
   With respect to the second premise
 that applicable regulatory controls
 would provide adequate control of
 mercury emissions from incineration,
 neither the incinerator or BIF
 regulations nor the LDR regulations
 specifically require the use of emission
 control devices that effectively capture
 mercury (e.g., activated carbon). As
 implemented in practice, the BIF
 regulations and some incinerator
 permits restrict mercury in the
 hazardous waste feed. Because feed  .
 restrictions are not so stringent as to
 eliminate mercury in the feedstream and
 because the current regulations do not
 require the use of emission control
 devices that efficiently capture arid
 remove mercury, it is still emitted to the
 atmosphere.33
   While the recently proposed (61 FR
 17358, April 19, 1996) Hazardous Waste
 Combustor Maximum Achievable
 Control Technologies (MACT)
 regulations will impose some emission
 limitations on mercury emissions from
 hazardous waste incinerators, cement
 kilns, and lightweight aggregate kilns,
 these regulations are unlikely to require
 the capture and recovery of mercury
 from the combustion emissions or other
 combustion residuals. Thus, the
 implementation focus at individual
 combustion facilities is expected to
 continue to be controlling feedrate
 levels of mercury-bearing hazardous
 waste into  the combustion device. The
 Agency is likely to determine under the
 final MACT rule that requiring specific
 APCDs on hazardous waste combustors
 to capture mercury is not cost-effective.
  Although feed restrictions can and do
 reduce mercury emissions and to some
 extent the associated risks, we are still
 concerned  with the environmental
 loading of mercury. The MACT rule
 does not take into account the long-
 range transport of mercury emissions,
 and  uncertainties in the HWC MACT
 risk  assessment allow the Agency to
 conclude only that risks from mercury
 emissions within 20 kilometers are
 likely to be small.34 The Agency wishes
 to consider whether we can further
 reduce the environmental loading by
 amending the LDR regulations to reduce
 the volume of mercury wastes that
  33 Mercury emissions can also be controlled under
special conditions imposed through RCRA omnibus
authority. See § 270.32(b).
  34 "Risk Assessment Support to the Development
of Technical Standards for Emissions from
Combustion Units Burning Hazardous Wastes:
Background Information Document," February 20,
1996.
 require IMERC and to promote the use
 of alternative treatment methods.
   Thus, the IMERC standard bears
 further investigation to see whether,
 given the heightened concern over all
 sources of mercury emissions, even ones
 at relatively low levels, alternative LDR
 approaches may be appropriate to
 ensure better protection of human
 health and the environment. We note
 that EPA must address any significant
 remaining residual risks posed by
 sources subject to the MACT
 technology-based standards within eight
 years after promulgation of the
 Hazardous Waste Combustor MACT
 standards. See section 112(f)(2). The
 Agency is required to impose additional
 controls if such controls are needed to
 protect public health with an ample
 margin of safety, or to prevent adverse
 environmental effects. Our mercury
 reevaluation in this proceeding is also
 expected to assist EPA in any residual
 risk evaluation.

 F. Additional Considerations Related to
 Alternatives to Incineration

   A possible alternative to incineration
 for some mercury-bearing wastes is the
 physical separation of the mercury
 containing and organic components of
 the waste streams. Mercury retorters
 report that mercury-bearing organic
 wastes may be separated prior to
 treatment, when the mercury is
 associated with particulates in the
 waste. After retorting of the particulates,
 the retort condenser sludge is separated
 and returned to the retorting process for
 additional mercury recovery. The
 residual organic phase with reduced
 mercury content is then incinerated.
 While such waste separations may be
 feasible for organic wastes containing
 inorganic mercury, such separations
 would likely not work for
 organomercury wastes. Thermal or other
 destruction of the organomercury
 compounds present appears to be
 needed to convert the organomercury
 compounds to a recoverable form, as
 was originally envisioned in the IMERC
 standard.

 G. Request for Comment

  The Agency has several potential
 concerns with the IMERC standard.
 Specifically, from the available
 combustion database and the BRS data,
 it appears that non-trivial volumes of
 mercury-bearing waste are going to
 combustion units. As discussed above,
 because mercury is a volatile metal and
unless the combustion unit has an
APCD capable of capturing mercury
emissions (normally not the case),
potentially all of the mercury fed into

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 28960
Federal  Register/Vol. 64, No. 103/Friday, May 28,  1999/Proposed  Rules
 the unit will be vaporized and released
 into the atmosphere.
  The Agency specifically requests
 comment on the following:

 1. What Mercury Waste Streams Will
 Continue to Warrant IMERC?

  There may be wastes for which
 incineration is the best available
 treatment option, for example, wastes
 with low mercury concentrations and
 high levels of organics, mercury wastes
 containing PCBs. and mercury wastes
 containing or combined with reactive
 and ignitable hazardous waste. In an
 attempt to identify such wastes, the
 Agency examined BRS data for wastes
 that are D009 and also contain dioxins
 or PCBs. A search of the 1995 BRS data
 showed only one hazardous waste
 incinerator that processed waste streams
 containing both D009 wastes and dioxin
 wastes. (EPA hazardous waste codes
 F020-F023 and F026-F028). According
 to the  1995 BRS, the facility processed
 approximately 80 tons of wastes
 containing dioxins from 27 separate
 waste streams. Many of these wastes are
 from soil and debris from facility
 decommissioning. However, no
 concentration data were available. Three
 facilities process waste streams
 containing both D009 wastes and PCB
 wastes. These facilities processed
 approximately 446 tons of wastes from
 22 separate waste streams in 1995. Most
 of the PCB wastes were organic solids
 and sludges and again, no concentration
 data were available. Waste streams
 containing reactive and ignitable
 hazardous wastes covered a wide
 variety of waste stream codes. Many of
 the Ignitable and reactive wastes were
 flammable liquids, solvents, and
 petroleum. In addition, it appears there
 are other waste streams, such as oily
 wastes, that require incineration.
  However, inorganic mercury is
 generally associated with solids in
 highly organic wastes. These mercury-
 bearing solids can be separated by
 centrifuge prior to retorting. The Agency
 requests information on mercury-
 bearing wastes that may continue to
 require incineration, and on wastes that
would be amenable to the separation of
mercury solids for recovery prior to
incineration of the remainder of the
waste.  Specifically, the Agency requests
comment on the feasibility of requiring
the separation of mercury-bearing solids
from organic wastes and identification
of any wastes for which such
pretreatment would not be feasible.
                    2. What Alternative Technologies Are
                    Available To Treat Mercury Wastes
                    Containing Organics While Also
                    Minimizing Mercury Emissions?
                      Because mercury emissions from
                    incinerators may be costly to  control,
                    alternative technologies are sought that
                    can either recycle the mercury in the
                    wastes, separate the mercury  from the
                    organics prior to incineration of the
                    organics, or produce a stable residue for
                    disposal that reduces the risks attributed
                    to the organic and mercury constituents.
                    The Agency seeks waste
                    characterization and technology
                    performance data on alternative
                    technologies for the treatment of wastes
                    that are currently incinerated.
                      We also request information on the
                    impediments to using alternative
                    technologies, such as RMERC, to treat
                    mercury wastes containing organics
                    (RMERC is currently listed as an
                    alternative in the regulations), and
                    whether the organics can be destroyed
                    or captured. Would an alternative
                    technology such as an oxidation-
                    leaching-precipitation train be more
                    desirable? What are the concentration
                    limits of organics that could be treated
                    by these alternative technologies? If
                    these alternative technologies are shown
                    to effectively treat mercury wastes
                    containing organics, should the
                    incineration standard then be retained
                    only if the unit has appropriate APCDs
                    to capture the mercury and/or only if
                    the organics in the wastes are  "hard to
                    treat?" The Agency specifically requests
                    comment and data supporting
                    commenter's views on these issues. The
                    Agency also requests information
                    regarding the current capacity of
                    alternative oxidation technologies.
                    VII. Regulatory Options Involving
                    Source Reduction
                     As discussed above, EPA's current
                    LDR regulations set both technology and
                    numerical based treatment standards
                    that require waste management facilities
                    to either retort, roast, or incinerate
                    hazardous wastes that contain greater
                    than 260 mg/kg of total mercury
                    (depending on the presence of organics;
                    see Table 4); or treat hazardous wastes
                    that contain less than 260 mg/kg of total
                    mercury to 0.025 mg/L TCLP prior to
                    land disposal.
                     Some companies have found ways to
                    reduce or eliminate the amount of
                    mercury in their waste by making
                    changes in their production processes
                    and plant management, including
                    changing raw materials, equipment,
                    process design, and maintenance
                   activities. In some cases, these changes
                   have taken several years to design, test
 and install, while simultaneously
 relying on costly treatment technology
 to remain in compliance. For example,
 chlor-alkali producers, which are the
 largest manufacturing users of mercury
 in the U.S., have historically relied on
 a mercury cell process to manufacture
 chlorine and caustic soda. Caustic soda
 produced from this process may contain
 mercury, which in turn may
 contaminate other products and
 generate mercury-bearing hazardous
 wastes. By 1994, approximately one-half
 of the chlor-alkali plants had changed to
 a membrane cell production process,
 which does not use mercury. The
 membrane cell process has resulted in
 better environmental results and lower
 energy and waste management costs for
 the facilities that use this technology.
   EPA wishes to consider regulatory
 options that produce superior
 environmental results and cost-savings
 for the regulated community beyond the
 requirements of end-of-pipe technology
 standards.  EPA recognizes that once a
 company invests in end-of-pipe
 recovery or treatment technologies that
 meet compliance requirements, there
 may be little or no incentive to invest
 more money in process changes that
 would reduce or eliminate a particular
 hazardous  waste, particularly since
 there would be no relief from waste
 management costs while process
 changes are being designed and tested.
   In today's document, EPA is seeking
 comment on potential regulatory
 incentives  that would encourage
 companies to invest in manufacturing
 process redesign, raw materials
 substitution or other technologies that
 would reduce the amount of mercury
 found in hazardous waste. To make this
 approach incentive-based, EPA is
 seeking views and information on the
 possibility  of extending LDR
 compliance dates for companies willing
 to develop  and/or install technologies
 that could be used instead of,  or in
 combination with, end-of-pipe
 technologies to reduce the generation of
 mercury-bearing hazardous wastes.
   One approach EPA is considering is a
 two-part LDR standard. The first part of
 this standard would be a traditional
 standard, developed from data on the
 best available treatment technologies.
The second and novel part of the
standard would be an alternative
standard that facilities could elect in
lieu of the first, more traditionally-based
standard. This alternative standard
would involve the installation of source
reduction-oriented process changes that
would either reduce the volume of
mercury waste produced or  the
concentration of mercury in the wastes.
As an incentive for encouraging

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                    Federal Register / Vol.  64, No.  103/Friday.  May 28,  1999/Proposed Rules
                                                                       28961
 companies to comply with the
 alternative standard (particularly if the
 mercury concentration level is lower
 than the level for the first part of the
 standard), EPA would extend the
 generator exclusion from permitting
 beyond the current 90 days, or provide
 some other kind of incentive.
   EPA is seeking comment on the
 development of a two-part standard, like
 the one discussed above, or another
 standard that provides economic or
 regulatory incentives to promote source
 reduction of mercury in hazardous
 wastes. EPA would also like comment
 on whether extending the compliance
 dates would foster  reductions in wastes
 beyond the limits achievable using end-
 of-the pipe treatment technologies.
 VIII. Mixed Wastes
   Ongoing inventory of mercury-
 contaminated wastes currently awaiting
 disposal at Department of Energy (DOE)
 facilities has identified 7,284 cubic
 meters of such wastes: These wastes are
 the legacy of past nuclear weapons
 production for national defense. Table 5
 presents an inventory of this waste.

   TABLE 5.—MERCURY CONTAINING  .
      WASTES AT DOE FACILITIES
Category
Elemental 	 	
<260 mg/kg 	
>260 mg/kg 	
Unknown 	

Total 	
Inventory
(cubic
meters)
17
6000
325
942

7.284
  Source:  DOE  Mercury  Working  Group,
 1999.
  Under current regulations, no separate
 treatment category exists for high
 mercury wastes that also contain
 radioactive materials. Therefore, the
 regulations direct that high mercury-
 organic subcategory mixed wastes be
 subjected to RMERC or IMERC and that
 high mercury-inorganic subcategory
 mixed wastes be subjected to RMERC.
 At the time of promulgation, these
 regulations intended that the mercury
 be separated from the wastes and
 recycled. However,  with the cessation of
 nuclear weapon production, there are
 no longer any uses for mercury that is
 still contaminated with radioactive
 materials. Thus, current regulations may
 result in the contamination (by
 radiation) of additional equipment to
 recover mercury that has no subsequent
 use and for which the treatment
standard for disposal is again RMERC.
Department of Energy's (DOE) Mixed
Waste Focus Area-Mercury Working
  Group, in conjunction,with EPA, has
  initiated studies of theidirect treatability
  of high mercury-inorganic subcategory
  wastes for direct disposal;: Should these
  tests demonstrate the successful
  treatment of such wastes, EPA could, as
  part of this or a separate LDR
  rulemaking, create a separate
  subcategory for these mercury-bearing
  mixed wastes and potentially develop a
  numerical treatment standard for the
  subcategory. These treatability studies
  include the evaluation of technologies
  such as alternative oxidation
  technologies, stabilization using
  specialized amendments, amalgamation
  technologies, sulfur polymer cement
  stabilization, and mercury solubilization
  and removal. Further information on
  these technologies is located in the
  docket to today's ANPRM. The Agency
  expects that several of these studies will
  be further along by the time of a
 proposed rule (scheduled to follow this
 ANPRM by approximately one year).
 Any available data, from these tests will
 be discussed in the proposed rule and
 placed in the docket to that rule.
   The Agency specifically requests
 comments on eliminating the RMERC
 standard for mixed mercury wastes, and
 on allowing the use of alternative
 technologies that are  currently being
 investigated by EPA and DOE, with the
 residuals having to comply with a
 numerical limit.

 IX. Discussion of Alternative Treatment
 Technologies

 A. Possible Alternative Technologies to
 Retorting
   As discussed in the May 1990 Best
 Demonstrated Available Technology
 (BOAT) Background Document for
 Mercury Containing Wastes, retorting is
 not the only technology that has been
 used in treating high mercury wastes.
 Alternative treatment technologies are
 categorized as either removal/recovery
 technologies or immobilization
 technologies. These alternatives are
 presently used, or could potentially be
 used for treating such wastes.
   Alternative treatment technologies
 presently exist, or have existed in the
 past, for two reasons. First, the
 alternative technology may be simply
 another competing process to remove
 mercury from, or fix mercury within, a
 matrix. Second, the technology may
 overcome restrictive waste
 characteristics that cause difficulty
 during retorting or roasting. For
 example, several processes are actually
 "pretreatment" processes to prepare the
waste for retorting. These processes
remove waste characteristics that
restrict treatment, such as water content.
  and convert mercury compounds into
  easier to treat forms.
    Several technologies which may hold
  some promise for the treatment of high
  mercury wastes include the following:
  Removal/Recovery Technologies
    (1) Acid/chemical leaching (solids,
  slurries, or aqueous wastes). The
  mercury is converted to a more soluble
  form and thus is removed from the
  waste matrix.
    (2) Carbon adsorption (aqueous
  wastes or vapors). Mercury retort
  facilities commonly use carbon
  adsorption as a way of removing and
  concentrating mercury removed from
  stack gas or effluents.
    (3) Ion exchange. Ions in  the exchange
  resin are substituted for mercury ions of
  similar charge.
   These technologies are described in
  more detail in the background
  document "Waste Specific Evaluation of
  RMERC Treatment Standard."

  Immobilization Technologies
   (1) Solidification/stabilization (solids
  or slurries). Solidification/
  stabilization (S/S) processes are
  nondestructive methods to immobilize
 the hazardous constituents in a matrix
 while decreasing the waste surface area
 and permeability.35 Common S/S agents
 include Type 1 Portland cement, lime,
 and fly ash. The final product can  be a
 monolith of any practical size or a
 granular material resembling soil.36
 Sulfur polymer cement (SPC) is one
 stabilization technology that can be
 used to convert mercury compounds to
 mercuric sulfide  and encapsulate
 simultaneously (U.S. DOE, 1998).
 However, the encapsulation process
 temperatures can volatilize mercury, so
 the mercury vapor and oxide that forms
 must be captured and recycled in the
 process.
   (2) Amalgamation. Amalgamation
 typically involves the mixing of
 elemental mercury with a  powdered
 granular metal (typically zinc), forming
 a non-liquid, semi-solid matrix of
 elemental mercury and the metal. Two
 generic processes that are used for
 amalgamating mercury in wastes are an
 aqueous replacement (solution) process,
 and a non aqueous process.37
  The Agency requests more
 information, including any data from
 treatability studies and their
  35 U.S. EPA, Technical Resource Document:
Solidification/Stabilization and its Application to
Waste Materials, EPA/530/R-93/012, June 1993.
  «U.S. EPA. Engineering Bulletin: Solidification/
Stabilization of Organics and Inorganics, EPA/540/
S-92/015, February 1993.
  37 U.S. EPA, Treatment Technology Background
Document, January 1991, pages 74-80.

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Federal  Register/Vol. 64, No.  103/Friday, May 28, 1999/Proposed Rules
 applications to various waste matrices,
 on these technologies.

 B. Possible Alternative Technologies to
 Incineration

  This section discusses the treatment
 technologies that are being studied to
 treat high mercury wastes currently
 requiring incineration. The goal of these
 technologies is to achieve the same
 degree of destruction of the organic
 compounds as is achieved with
 incineration, while maintaining control
 over the residual mercury. Many
 variables need to be considered,
 Including the degree of organic
 destruction required prior to further
 mercury treatment, the degree of
 mercury speciation control required by
 the waste form, and other operating
 procedures to ensure mercury extraction
 from nonwastewaters and wastewaters.
 Because the mercury cannot be
 destroyed, various treatment process
 steps are necessary to treat or recover
 the mercury, depending on the mercury
 species present in the waste, its
 concentration, and the overall waste
 form.
  Currently, the only common process
 capable of destroying organics is
 oxidation, which can be done thermally
 or chemically. It is usually combined
 with other technologies to form a
 treatment train. One such train is the
 oxidation, leaching, and precipitation
 train, which has been shown to be
 effective in treating high mercury wastes
 currently requiring incineration. Once
 the organics are destroyed, leaching and
 precipitation treat the inorganic
 mercury forms, such as oxides and
 hydroxides. The resulting waste is then
 suitable for retorting or immobilization
 prior to disposal. Note that this type of
 treatment train cannot destroy dioxins,
 furans, or PCBs.
  The  Agency also has limited
 information on a number of developing
 technologies including nonthermal (i.e.,
 Delphi DETOX (Delphi Research), Direct
 Chemical Oxidation (LLNL), Acid
 Digestion (Savannah River)) and thermal
 processes  (such as steam reforming)
 (ThermoChem Inc.), and Catalytic
 Chemical Oxidation (LBNL))  under
 development in support of the waste
 treatment needs of the Department of
 Energy facilities. One or more of these
 technologies may soon be available and
 used for mercury-bearing wastes,
 followed by stabilization.  EPA requests
 further information on the
 aforementioned technologies, as well as
any others that may be used in place of
1MERC.
                    C. Current Mercury Treatment
                    Companies
                     Several sources were researched to
                    identify facilities and companies that
                    provide alternative treatment for
                    mercury-bearing organic wastes. These
                    sources include BDAT capacity
                    background documents, the 1995
                    Biennial Reporting System (BRS),
                    Alternative Technology Treatment
                    Information Center (ATTIC) database,
                    Vendor Information System for
                    Innovative Treatment Technologies
                    (VISITT) database, technical background
                    documents, online web searches for  .
                    company and treatment technology
                    profiles, and the Risk Reduction
                    Engineering Laboratory  (RREL)
                    database. Limited information is
                    available on vendors and facilities that
                    treat mercury-bearing organic wastes
                    using methods other than incineration
                    or retorting. BRS data indicate that there
                    are numerous facilities that treat
                    mercury-bearing organic wastes. The
                    BRS waste management code, the  code
                    used to report the final treatment of the
                    waste, in a few cases indicated there is
                    acid leaching or oxidation used to treat
                    the mercury-bearing organic waste
                    stream. This may be because the final
                    treatment step is the only management
                    code reported, and does not indicate if
                    a multiple step process is used. The
                    predominant treatments reported in BRS
                    are stabilization/chemical fixation using
                    cementitious and/or pozzolanic
                    materials and phase separation. There
                    are several data gaps that require further
                    investigation on a process and waste
                    stream specific level. In addition, the
                    BRS data do not adequately describe the
                    organic content of the actual waste
                    stream being treated, especially where
                    multiple waste form codes are reported
                    together with the D009 code. A table
                    listing the mercury treatment facilities is
                    provided in the background document
                    "Analysis of Alternatives to Incineration
                    for Mercury Wastes Containing
                    Organics," which can be found in the
                    docket to today's ANPRM.

                    D. Request for Comment
                     The Agency seeks comments on the
                    viability and parameters of these
                    alternative technologies and any other
                    technologies not specifically mentioned
                    in this ANPRM. Specifically, the
                    Agency seeks the following information:
                    description of the process; types of
                   wastes capable of being treated; total,
                    leachable, and volatile mercury content
                   of the wastes and of the residues
                   following treatment; amount of mercury
                   air emissions from treatment; operating
                   conditions and parameters; data
                   showing the efficiency of the
 technology; commercial availability of
 the technologies and their available
 capacity; limitations of the technologies;
 cost information for these alternative
 technologies; and other potential
 benefits of using these alternative
 technologies over the existing treatment
 technologies. All data submitted should
 have appropriate QA/QC documentation
 to ensure their consideration by the
 Agency. Data without QA/QC may be
 disregarded.

 X. Possible Revisions to the Mercury
 LDRs

 A. Purpose of ANPRM
  The Agency plans to examine
 potential revisions to the LDR mercury
 treatment standards, including the
 potential to encourage manufacturing
 process changes (i.e., source reduction
 changes) that further reduce the amount
 of mercury entering hazardous waste
 streams, as the next step in this
 rulemaking process. The Agency
 decided that this ANPRM is necessary
 before proposal development because
 the Agency would benefit from
 additional mercury treatment data,
 including information on source
 reduction opportunities, as well as
 industry information to consider in
 amending the standards. The nature and
 extent of these amendments have not
 yet been determined. This ANPRM is
 expected to be beneficial to the
 regulating entities (including States), the
 regulated community, and the public as
 a means of public outreach and
 opportunity for public comment early in
 the rulemaking process. EPA encourages
 all interested persons to submit
 comments, and to identify any relevant
 issues not addressed by this ANPRM.
 The Agency also welcomes comments
 regarding whether the LDR mercury
 treatment standards should be revised.
 The Agency encourages commenters to
 submit examples or documentation to
 support their positions. The input from
 public comment will assist the Agency
 in developing a proposed rule that
 successfully addresses all appropriate
 revisions to these standards. An Agency
 decision to issue a proposed rule to
 revise LDR mercury treatment standards
 and the nature of those revisions will be
 ultimately based on the comments
 received on this ANPRM, as well as data
 obtained from other sources (e.g.,
 ongoing treatability studies).

 B. Schedule
  The Agency has general plans to
release a notice of proposed rulemaking
 by early 2000. The final rule date will
depend on the amount of information
submitted and the issues raised.

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                   Federal Register/Vol.  64,  No. 103/Friday, May 28,  1999/Proposed Rules
                                                                      28963
 C. Impact on Small Businesses
   The Agency believes, at this point,
 that the impact on small businesses will
 not be significant. EPA requests
 comment on the potential costs and
 benefits to small businesses, should
 revisions be made to the LDR mercury
 treatment standards as described in this
 ANPRM. Suggestions on ways the
 Agency might mitigate any adverse
 effects would also be welcome. .

 D. Impact on State Programs
   The Agency will be cognizant of the
 impact of any proposed revisions to the
 LDR mercury treatment standards on
 State programs, and encourages
 comments on this subject.

 XI. Administrative Requirements

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

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

 List of Subjects in 40 CFR Part 268
   Environmental protection, Hazardous
 waste, Reporting and recordkeeping
 requirements
   Dated: May 21, 1999.
 Carol M. Browner,
 Administrator.
 [FR Doc. 99-13659 Filed 5-27-99; 8:45 am]
 BILLING CODE 6560-50-P
 FEDERAL EMERGENCY
 MANAGEMENT AGENCY

 44 CFR Part 67

 [Docket No. FEMA-7290]

 Proposed Flood Elevation
 Determinations

 AGENCY: Federal Emergency
 Management Agency (FEMA).
 ACTION: Proposed rule.

 SUMMARY: Technical information or
 comments are requested on the
 proposed  base (1% annual chance) flood
 elevations and proposed base flood
 elevation  modifications for the
 communities listed below. The base
 flood elevations and modified base
 flood elevations are the basis for the
 floodplain management measures that
 the community is required either to
 adopt or to show evidence of being
 already in effect in order to qualify or
 remain qualified for participation in the
 National Flood Insurance Program
 (NFIP).
 DATES: The comment period is ninety
 (90) days following the second
 publication of this proposed rule in a
 newspaper of local circulation in each
 community.
ADDRESSES: The proposed base flood
elevations for each community are
 available for inspection at the office of
 the Chief Executive Officer of each
 community. The respective addresses
 are listed in the following table.

 FOR FURTHER INFORMATION CONTACT :
 Matthew B. Miller, P.E., Chief, Hazards
 Study Branch, Mitigation Directorate,
 Federal Emergency Management •
 Agency, 500 C Street SW., Washington,
 DC 20472, (202) 646-3461, or (e-mail)
 matt.miller@fema.gov.

 SUPPLEMENTARY INFORMATION : The
 Federal Emergency Management Agency
 proposes to make determinations of base
 flood elevations and modified base
 flood elevations for each community
 listed below, in accordance with Section
 110 of the Flood Disaster Protection Act
 of 1973, 42 U.S.C. 4104, and 44 CFR
 67.4(a).
   These proposed base flood and
 modified base flood elevations,  together
 with the floodplain management criteria
 required by 44 CFR 60.3, are the
 minimum that are required. They
 should not be construed to mean that
 the community must change any
 existing ordinances that are more
 stringent in their floodplain
 management requirements. The
 community may at any time enact
 stricter requirements of its own, or
 pursuant to policies established by other
 Federal, State, or regional entities.
 These proposed elevations are used to
 meet the floodplain management
 requirements of the NFIP and are also
 used to calculate the appropriate flood
 insurance premium rates for new
 buildings built after these elevations are
 made final, and for the contents in these
 buildings.

 National Environmental Policy Act

  This proposed rule is categorically
 excluded from the requirements of 44
 CFR Part 10, Environmental
 Consideration. No environmental
 impact assessment has been prepared.
 Regulatory Flexibility Act

  The Associate Director for Mitigation
 certifies that this proposed rule is
 exempt from the requirements of the
 Regulatory Flexibility Act because
 proposed or modified base flood
 elevations are required by the Flood
 Disaster Protection Act of 1973, 42
 U.S.C. 4104, and are required to
establish and maintain community
eligibility in the NFIP. No regulatory
flexibility analysis has been prepared.

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