Friday
May 2, 1997
Part III
Environmental
Protection Agency
40 CFR Part 60, et al.
Revised Technical Standards for
Hazardous Waste Combustion Facilities;
Proposed Rule
2421
-------
24212
Federal Register / Vol. 62. No. 85 / Friday. May 2, 1997 / Proposed Rules
ENVIRONMENTAL PROTECTION
AGENCY
40 CFR Parts 60,63,260,261,264,265,
266,270, and 271
[FRL-5818-9J
Revised Technical Standards for
Hazardous Waste Combustion
Facilities
AGENCY: Environmental Protection
Agency (EPA).
ACTION: Notice of data availability and
request for comments.
SUMMARY: This document Is a notice of
availability and invitation for comment
on the following Information pertaining
to the proposed revised standards for
hazardous waste combustors (61 FR
17358 (April 19.1996)): Report on the
status of setting national emission
standards for hazardous air pollutants
(NESHAPS) based on the revised
emissions database; Report on the '
selection of pollutants and source
categories, including area and major
sources; report on the status of various
implementation Issues, Including
compliance dates, compliance
requirements, performance testing, and
notification and reporting requirements;
and report on the status of permit •
requirements, including waste
minimization incentives. ,
DATES: Written comments must be
submitted by June 2.1997.
ADDRESSES: Commenters must send an
original and two copies of their
comments referencing docket number
F-97-CS4A-FFFFF to: RCRA Docket
Information Center, Office of Solid
Waste (5305G). U.S. Environmental
Protection Agency Headquarters (EPA,
HQ), 401M Street, SW.. Washington,
DC 20460. Deliveries of comments '
should be made to the Arlington,
Virginia address listed below.
Comments may also be submitted
electronically through the Internet to:
rcra-docketeepamaiLepa.gov.
Comments In electronic format should
also be identified by the docket number
F-97-CS4A-FFFFF. All electronic
comments must be submitted as an
ASCII file avoiding the use of special
characters and any form of encryption.
For other information regarding
submitting comments electronically or
viewing the comments received or
supporting information, please refer to
the proposed rule (61 FR 17358 (April
19,1996)).
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: RCRA CBI .
Document Control Officer, Office of
Solid Waste (5305W), U.S. EPA, 401 M
Street, SW., Washington, DC 20460.
Public comments and supporting
materials are available for viewing in
the RCRA Information Center (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.*
FOR FURTHER INFORMATION CONTACT: For
general information, contact the RCRA
Hotline at 1-800-424-9346 or TDD 1-
800-553-7672 (hearing impaired). In
the Washington metropolitan area, call
703-412-9810 or TDD 703-412-3323.
The RCRA Hotline is open Monday-
Friday, 9 a.m. to 6 p.m., Eastern
Standard Time. The RCRA Hotline can
also provide directions on how to access
electronically some of the documents
and data referred to in this notice via •
EPA's Cleanup Information Bulletin
Board System (CLU-IN). The CLU-IN
modem access phone number is 301-
589-8366, or Telnet to clu-in.epa.gov for
Internet access. The flies posted on
CLU-IN are in Portable Document
Format (PDF) and can be viewed and
printed using Acrobat Reader.
For more detailed information on
specific aspects of this notice, contact
Larry Denver, Office of Solid Waste
(5302W), U.S. Environmental Protection
Agency, 401 M Street, SW., Washington,
DC 20460,703-308-8770, e-mail
address: denyer.larry@epamail.epa.gov.
SUPPLEMENTARY INFORMATION:
The Agency specifically solicits
comment on the following documents:
(1) Draft Technical Support Document
for HWC MACT Standards (NODA),
Volume I: MACT Evaluations Based on
Revised Database, April 1997.
(2) Draft Technical Support Document
for HWC MACT Standards (NODA),
Volume It: Evaluation of CO/HC and
DRE Database, April 1997.
(3) Draft Technical Support Document
for HWC MACT Standards (NODA),
Volume m: Evaluation of Metals
Emissions Database to Investigate
Extrapolation and Interpolation Issues,
April 1997.
In preparing diis notice, the Agency
considered comments on the proposed
rule, including those listed below. EPA*
is soliciting responsive comments
regarding certain data and information
presented in these comments:
(1) Cement Kiln Recycling Coalition
(2) Chemical Manufacturers
Association
(3) Coalition for Responsible Waste
Incineration
(4) Don Clay Associates
. (5).The Dow Chemical Company
(6) Environmental Technology
Council
(7) Holnam Inc.
(8) Lafarge Corporation
(9) Molten Metal Technology, Inc.
(10) The Natural Resources Defense
Council, Inc.
(11) Rollins Environmental Services,
Inc.
(12) Safety-Kleen Corp.
(13) Texas Natural Resource
Conservation Commission
(14) vonRoll/WTI
Readers should note that only
comments about new information
discussed in this notice will be
considered by the Agency. Issues related
solely to the April 19,1996 proposed
rule and other subsequent notices that
are not directly affected by the
documents or data referenced in today's
Notice of Data Availability are not open
for further comment.
Glossary of Acronyms
acfm—Actual Cubic Feet per Minute
ACI—Activated Carbon Injection
APCD—Air Pollution Control Device
BIF—Boiler and Industrial Furnace
BTF—Beyond-the-Floor
CAA—Clean Air Act
CEMS—Continuous Emissions
Monitoring System
D/F—Dioxins/Furans
ESP—Electrostatic Precipitator
gr/dscf— Grains per Dry Standard Cubic
Foot
HAP—Hazardous Air Pollutant
HC—Hydrocarbons
HWC/HWI—Hazardous Waste
Combustor/Incinerator
• IWS—Ionizing Wet Scrubber
LVM—Low-volatile Metals
LWAK—Lightweight Aggregate Kiln
MACT—Maximum Achievable Control
Technology
MTEC—Maximum Theoretical Emission
Concentration
NESHAPs—National Emission
Standards for HAPs
NODA—Notice of Data Availability
NPRM—Notice of Proposed Rulemaking
NSPS—New Source Performance
Standards
PM—Paniculate Matter
RCRA—Resource Conservation and •
Recovery,Act
SRE—System Removal Efficiency
SVM—Semi-volatile Metals
TEQ—Toxic Equivalent
Jig/dscm—Micrograms per Dry Standard
Cubic Meter
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
24213
TABLE OF CONTENTS
Part One: Background and Overview of
Today's Notice
I. Background '
n. Overview of Today's Notice
Part Two: Standards For Hazardous Air
Pollutants (NESHAPs)
I. Regulation of Area Sources
' A. Approach to Regulate Area Sources, as
Proposed
B. Positive Area Source Finding for HWCs
C. Title V Permitting Requirements for
Area Sources
n. Revisions to Proposed Standards Using the
Revised Emissions Database and Data
Analysis Methods
. A. Notice of Data Availability on the
Revised Emissions Database
B. I'M as a Surrogate for Non-Hg Metals
C. Options for Controlling Emissions of
Organic HAPs
D. Accounting for Emissions Variability in
Establishing Emission Standards
E, Re-Evaluation of Proposed MACT
Standards for Incinerators
F. Re-Evaluation of Proposed MACT
Standards for Cement Kilns
G. Re-Evaluation of Proposed MACT
Standards for Lightweight Aggregate
Kilns
Part Three: Implementation
I. Compliance Date Considerations
A. Definition of Compliance Date
B. Pre-Certification of Compliance
C. Consequences of Non-compliance
n. Compliance Requirements
A. Compliance with CO and/or HC
Emission Standards
. B. Startup, Shutdown, and Malfunction
Plans
C. -Metals Extrapolation and Interpolation
Considerations
D. Consideration of Site-Specific Variances
for Cement Kilns and LWAKs
E. Emissions Averaging for Cement Kilns
IE. ORE Testing Considerations
A. Options for Ensuring Compliance with
a DRE Standard
B. DRE As a MACT Versus RCRA Standard
IV. Notification and .Reporting Requirement •
Considerations
A. Public and Regulatory Notification of
Intent to Comply
B. Data Compression Allowances.
V. Waste Minimization and Pollution
Prevention
A. Overview
B. EPA Proposed Flexible Waste
Minimization Incentives
C. Comments Received
D. Comments Requested on Additional
Waste Minimization Incentives
VI. Permit Requirements
A. Coordination of RCRA and CAA
Permitting Processes
B. Permit Process Issues
C. Omnibus and RCRA/CAA Testing
Coordination
Part Four: Miscellaneous Issues
I. 5000 Btu per Pound Policy for Kiln
Products
n. Foundry Sand Thermal Reclamation Units
A. Background
B. Deferral and Variance Options for
Consideration
m. Status of Gaseous Fuels Generated from
Hazardous Waste Management Activities
IV. Regulatory Flexibility Analysis
Part One: Background and Overview of
Today's Notice
/. Background
On April 19, 1996, EPA proposed
revised standards for three source
categories of hazardous waste
combustors (i.e., hazardous waste
incinerators and hazardous waste-
burning cement kilns and lightweight
aggregate kilns (LWAKs)), 61 FR 17358.
After an extension, the comment period
closed on August 19,1996.
The Agency subsequently published
two Notices of Data Availability
(NODA). The first NODA, published on
August 23,1996 (61 FR 43501) invited
comment on information pertaining to a
peer review of three aspects of the
proposed rule, additional analyses of
fuel oils that would be used to establish
a comparable fuels exclusion, and
information on a synthesis gas process.
The comment period on that NODA
closed on September 23,1996. The
second NODA. published on January 7,
1997 (62 FR 960) provided notice and
opportunity to comment on an updated
hazardous waste combustor database
containing the emissions and ancillary
data that the Agency plans to use to
develop the final rule. The comment
period on that NODA closed on
February 6,1997.
EPA's proposal to revise standards for
hazardous waste incinerators and
hazardous waste-burning cement kilns
and LWAKs is under joint authority of
the Clean Air Act, as amended, (CAA)
and the Resource Conservation and
Recovery Act, as amended (RCRA). The
proposed emission standards were
developed under the CAA provisions
concerning die maximum level of
achievable control over hazardous air
pollutants (HAPs), taking into
consideration the cost of achieving the
emission reduction, any non-air quality;
health and .environmental impacts, and
energy requirements. These Maximum -
Achievable Control Technology (MACT)
standards, also re ferred to as National
Emission Standards for Hazardous Air
Pollutants (NESHAPs), were proposed
for the following HAPs: dioxins/furans
(D/F), mercury, two semi-volatile metals
(lead and cadmium), four low volatility
metals (antimony, arsenic, beryllium,
and chromium), particulate matter, and
hydrochloric acid/chlorine gas. Other
toxic organic emissions were addressed
by standards for carbon monoxide (CO)
and hydrocarbons (HC).
Because of the joint authorities for
this rule, the proposal also contained an
implementation scheme to harmonize
the RCRA and CAA programs to the
maximum extent permissible by law. In
pursuing a common-sense approach
towards this objective, the proposal
sought to establish a framework that: (1)
Provides for combined (or at least
coordinated) CAA and RCRA permitting
of these facilities; (2) allows maximum
flexibility for regional, state, and local
. agencies to determine which of their
resources will be used for permitting,
compliance, and enforcement efforts;
and (3) integrates the monitoring,
compliance testing, and record keeping
requirements of the CAA and RCRA so
that facilities will be able to-avoid two
potentially different regulatory
compliance schemes.
II. Overview of Today's Notice
The Agency received a large number
of public comments in response to the
proposal. The Agency evaluated the
public comments received and their
applicability to die proposed rule. In
those instances where comments
provided new information or new
insights, the Agency has reevaluated
certain aspects of the proposal based on
this new information. The Agency is
issuing this NODA in an effort to inform
the public of: (1) Significant changes the
Agency is considering on aspects of die .
proposal based on public comments and
new information; and (2) die Agency's
own reevaluation (and to some degree
narrowing) of MACT standard-setting
approaches based on new data and (at
least in part) on public comments.
Part Two: Standards for Hazardous Air
Pollutants (NESHAPs)
/. Regulation of Area Sources
In diis section, we solicit comment on
making a positive area source finding to
subject hazardous waste combustor area
sources to die same MACT standards
diat would apply to major sources and
on whether, under such a finding, area
sources should be subject to Title V
permit requirements.
A. Approach To Regulate Area Sources,
as Proposed
A major source is a source that has die
potential to emit (considering controls)
either 10 tons per year of any hazardous
air pollutant or 25 tons of any
combination of HAPs. Area sources are
any sources which are not major
sources.
• The Agency proposed to subject area
sources to MACT standards under
authority of CAA section 112(c)(6). See
61 FR at 17365. That section requires
-------
24214
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
the Agency to subject to MACT
standards' all sources in source
categories that account for not less than
90 percent of the aggregate emissions of
each enumerated pollutant2 The
enumerated pollutants emitted by
hazardous waste combustors (HWCs)
Include mercury (Hg), D/F, and other
polycyclic organic HAPs. The Agency
explained at proposal that HWCs were
significant emitters of D/F and Hg, and
that much of the human health risk from
emissions of HAPs from HWCs comes
from these high priority HAPs, and-
D/F In particular.
We received many comments
pertaining to this part of the proposal,
and we will address those comments in
the final rule. The area source issue is
discussed in today's notice because
commenters said that another, more
appropriate reading of section 112(c)(6)
is that this authority could be used to
apply MACT control to area sources
only for the enumerated HAPs, not the
full array of HAPs that the Agency
proposed to regulate (e.g., particulate
matter (PM). semlvolatile metals (SVM),
low volatile metals (LVM)).
Nonetheless, were EPA. to adopt this
reading, the Agency continues to believe
that area sources need to be regulated
for this full array of HAPs.
In light of issues commenters raised,
we solicit comment on an alternative
approach that would subject area
sources to all of the MACT standards for
major sources based on the Agency
making a positive area source finding.
B. Positive Area Source Finding For
HWCs
Area sources must be regulated by
technology-based standards3 if the area
source category is listed pursuant to
section 112(c)(3) based on the Agency's
finding that these sources (individually
or In the aggregate) present a threat of
adverse effects to human health or the
environment. Such a finding is termed
a positive area source finding. The
Agency is today soliciting comment on
whether a positive area source finding is
appropriate for hazardous waste
' For area sources, section J12(c)(S) requires the
Agency to establish cither MACT standards under
section 112(d) (2), or generally available control
technology (GACT) standards under section
nzy)(5). Given the similarities between major and
area source HWCs is discussed in subsequent
sections of the text, area sources should be subject
wMACT.
=Section 112(c)(6) enumerates the following high-
priority hazardous pollutants for special regulation:
alkytofed lead compounds, polycyclic organic
matter, hexachlorobenzene, mercury,
polychlorinaeed blphcnyls, and 2.3.7,8-
tetrachlorodibenzofurans and p-dtoxin.
»That if, MACT standards under section
11Z (d] (2) or GACT standards under section
11260(5).
incinerators and hazardous waste
burning cement kilns and lightweight
aggregate kilns.
A positive area source finding would
be based on the risk assessment
performed for the proposed rule and
ultimately the final rule. Even though
the sources modeled in support of the
proposed rule may have met the
definition of a major source, EPA
believes their HAP emissions, other
than HC1, are also representative of area
source emissions. This is because, as
discussed below, these example sources
may be able to reduce their HC1 '
emissions to become area sources
without reducing emissions of D/F, Hg,
or other metal HAPs that could pose
significant health risk.4
Many comments were submitted .on
the risk assessment methodology used
to support the proposed rule. We are
considering these comments in
development of the final rule and are
making appropriate changes to the risk
methodology, including modeling
additional facilities. These changes
could affect the Agency's findings for
both major and area sources. The
Agency is not today reopening the
comment period on the risk assessment
1. Risks that could be posed by area
source incinerators. We showed at
proposal that baseline emissions from
incinerators could pose high end
individual lifetime cancer risks from D/
F up to 9E-5. See 61 FR at 17389. In
addition, although the risk from low
volatile metals (i.e., As, Be, Cr, and Sb)
was not estimated to exceed 4E-6, the
example sites modeled were not
representative of the short stacks .of
many on-site incinerators. The direct
inhalation component of the individual
cancer risk estimates may increase when
incinerators with short stacks are
included in the risk assessment
supporting the final rule.
2. Risks that could Be posed by area
source cement kilns. The Agency
showed at proposal that baseline
emissions from cement kilns could pose
high end individual lifetime cancer
risks from D/F up to 9E-5. See 61 FR at
17402. Although several high D/F-
emitting cement kilns have recently
reduced their D/F emissions
significantly, a revised risk assessment
may well show that cement kilns (both
area and major sources) can pose
significant health risk at current
emission levels.
3. Risks that could Be posed by area
source lightweight aggregate kilns.
Although the Agency did not show high
baseline D/F cancer risks for LWAKs at
proposal, the risk assessment assumed
extremely low D/F emissions—0.04 ng
TEQ/dscm—based on very limited data
from a single LWAK. However, as
discussed below in section II.G, new
data from two additional LWAKs show
substantially higher emission levels—up
to 4.1 ng TEQ/dscm. At these emission
levels, the high end individual lifetime
cancer risk from D/F could exceed
1E-5.
4. Basis for a positive area source
• finding. In evaluating these estimated
risk levels to determine whether they
are sufficient to make a positive area
source finding, the Agency considered
. other factors which EPA believes to be
relevant in determining how to exercise
its discretion regarding area source
determinations for these sources:
a. HWC area sources can pose the
same hazard to human health or the
environment as major sources. An area
source may have the same emission
rates of HAPs other than hydrogen
chloride (HC1, the principal HAP that
causes a HWC to be a major source) as
a major source, and thus pose
essentially the same hazard to human
health or the environment. In other
words, sources could have HC1
emissions low enough to avoid a major
source classification, but have emissions
of D/F that could pose a health risk
given that there is no direct correlation
between HC1 and D/F emissions.5
In addition, some HWCs that would
currently be classified as major sources
because of their HC1 emissions may be
able to lower their HC1 emissions to
become area sources. The Agency
projects that all LWAKs are currently
major sources principally because of
their HC1 emissions, and that
approximately 80 percent of cement
kilns are major sources, again because of
HC1. These HWCs may be able to lower
their HC1 emissions to otherwise
become area sources.6
Sources have until the compliance
date of the MACT standards (i.e., three
years after publication in the Federal
4 From a technical perspective related to the
nature of common air pollution control devices,
reducing HC1 emissions would not generally reduce
emissions of other HAPs.
5 For well-designed and operated combustion
systems, D/F emissions are related primarily to
post-combustion particle surface catalyzed
reactions and the temperature of the combustion gas
(the optimum temperature window for formation is
450-750 0F), virtually irrespective of HC1
concentrations in the gas.
6 Some commercial incinerators may also be able
to lower their allowable HC1 emission levels to
become area sources. It could be more problematic
for on-site incinerators to lower their emissions to
become area sources because facility-wide HAP
emissions must be considered when making the
major/area source determination: For example, on-
site incinerators located at large chemical
production facilities would need to reduce HAP
emissions at a large number of sources.
-------
Federal Register / Vol. 62. No. 85 / Friday. May 2. 1997 / Proposed Rules
24215
Register) to make a major source
determination. Many kilns spiked
chlorine in the hazardous waste feed
during compliance testing to get
approval to feed chlorine (and emit HC1/
C12) at levels ostensibly higher than
normal. Given that sources "have the
potential to emit'.' at these ostensibly
higher than normal emission rates, these
emission rates must be used for the
major source determination. See CAA
section 112(a)(l), definition of major
source. These sources may be able to
operate successfully at lower allowable
chlorine feedrates and'emission rates,
however. If so, they can elect to retest
their units and base the major/area •
source determination on potentially
lower HC1/C12 emission rates.
b. RCRA sections 3004 (o) (2) and
3004(q) essentially command regulation
of all HWCs. Under this RCRA mandate,
the Agency has regulated all (i.e., both
major and area sources) hazardous
waste incinerators since 1981 (see 46 FR
7678 (Jan. 23,1981) as amended at 48
FR 14295 (Apr. 1,1983)) and all
hazardous waste burning cement and
lightweight kilns since 1991 (see 56 FR
7134 (Feb. 21, 1991)). Deferring
regulation of HWCs to the CAA would
not be appropriate unless all HWC
sources were covered. In addition,
although somewhat more than half of
the commercial incinerators appear to
be area sources, the majority of on-site
incinerators are likely to be major
sources.7 The public expectation is that
all HWCs would continue to be
regulated.?
c. MACT controls are reasonable and
appropriate for both major and area
sources. The emission control
equipment (and where applicable,
feedrate control) defined as floor or
beyond-the-floor (BTF) control for each
source category is applicable and
appropriate to area sources. There is
nothing unique about the types and
concentrations of emissions of HAPs
from area sources versus major sources
that would make MACT inappropriate
for an area source.
d. Area source HWCs contribute
significantly to D/F and Hg emissions. . '
Both area and major source HWCs
contribute significantly to aggregate
emissions of D/F and Hg, two high
' Only approximately 30 percent of incinerators
appear to be major sources. This estimate is based
on only the incinerators' stack emissions, however.
Given that facility-wide emissions of HAPs are
considered when making a major source
determination, many on-site incinerators are likely
to be classified as major sources because they are
located at large petrochemical facilities.
8 It would be particularly problematic from a
RCRA perspective for commercial incinerators that
are area sources to be exempt from MACT
standards.
priority HAPs. See CAA section
112(c)(6) and proposal eliscussion at 61
FR at 17366.
For these reasons, the Agency is
taking comment on making positive area
source findings for each of the three
source categories covered by the
proposal. Again, the effect would be to
subject all sources within these
categories to MACT standards, which
also would be the effect of the original
proposal.
•C. Title V Permitting Requirements for
Area Sources
Under § 63.1 (c) (2), area sources
subject to MACT (or. GACT) are subject
to the requirement to obtain a Title V
permit unless the standard for the
source category (e.g., Subpart EEE for
HWCs) specifies that: (1) States will
have the option to exclude area sources
from Title V permit requirements; or (2)
States will have the option to defer
permitting of area sources. The Agency
has determined that if it makes a
positive area source finding and subjects
area sources to MACT standards as
discussed above, the Agency would also
consider subjecting area sources •
immediately to Title V permitting
requirements, as provided by
§63.1(c)(2)(iii). The Agency has
determined that area source compliance
with Title V permit requirements would
not be "impracticable, infeasible, or
unnecessarily burdensome". See CAA
section 502(a). As noted above, area
sources can be virtually identical to
major sources with respect to size, type
of combustor, and commercial versus
on-site status, except that their mass
emissions of HC1 are lower. Thus,
waiver of Title V permitting would not
be warranted.
In addition, if the Agency were to
waive the Title V permit requirement for
area sources, we would be concerned
about the confusion it would likely
create for the regulated community and
the public if the air emissions standards
for some hazardous waste combustors
(even in the same source category) were
addressed in the Title V permitting
process and the air emissions standards
for others were addressed in the RCRA .
permitting process. Since a source can
make modifications to their emissions
levels that could change their major/
area source determination, a source
could move from one permitting
program to the other, creating
difficulties for the permitting agencies
in tracking sources and for the public in
trying to participate in or follow the
permitting process. Therefore, it appears
most appropriate from an
implementation standpoint to subject
area sources to Title V permitting. In
this way, all HWCs (both major and area
sources) would be subject to the same
Title V permitting requirements.
II. Revisions to Proposed Standards
Using the Revised Emissions Database
and Data Analysis Methods.
In this section, the Agency discusses
comments on the revised emissions
database and the revised standards that
would result from applying an
engineering evaluation and data
analysis methods to that revised
database. In addition, we discuss several
issues that are generic to the MACT
standards for all three source categories:
(1) Consideration of PM as a surrogate
for non-Hg metal HAPs; (2) options for
controlling emissions of organic HAPs;
and (3) emissions variability.
A. Notice of Data Availability on the
Revised Emissions Database
On January 7, 1997 the Agency
published a NODA on an updated
database of emissions and ancillary
information. See 62 FR .960. The Agency
updated the database used at proposal
to correct errors and include additional
emissions data. The NODA explained
that the updated database would be
used to identify MACT standards for the
final rule and to evaluate economic
impacts and, for RCRA purposes, risks
associated with the final MACT
standards.
The Agency received comments on
the revised database from 16
stakeholders representing the cement
industry, lightweight aggregate industry,
and on-site and commercial
incinerators. The database was revised
again to accommodate the comments
received on the database NODA. The
Agency then re-analyzed the database .to
determine the MACT floor standards
discussed below.
We received several specific
comments (i.e., as opposed to generic
and undocumented comments that for
example, the Agency's data are
inconsistent with the commenter's) that
were not accompanied with supporting
documentation. Most of these comments
pertain to miscellaneous data on
feedstream feedrates and equipment
design information that do not have a
significant impact on developing MACT
floor standards under the data analysis
methods discussed in today's NODA.
Where there was a significant possibility
that the data might affect the Agency's
determinations, references were re-
checked to determine the more accurate
number to be used.
The Cement Kiln Recycling Coalition
(CKRC) provided an extensive run-by-
run, HAP-by-HAP comparison of the
Agency's database with theirs. While
-------
24216
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
potentially useful in some cases, their
submission unfortunately did not
distinguish between significant versus
insignificant differences; nor did they
verify which data were more accurate
for the purposes in question. Within
current time constraints, the Agency has
identified which appear to us to be
significant and relevant differences and
then checked these data to determine
which appear to be more accurate and
has made necessary changes. The
current database, as updated and
revised, is appropriate and sufficient
considering the engineering and data
analysis methods discussed below to
Identify MACT standards. For example,
although there may still remain
differences between CKRC's and the
Agency's database regarding
electrostatic preclpitator (ESP) and
fabric filter design and performance
characteristics, those characteristics are
not germane to the engineering and data
analysis methods for determining
relevant MACT standards, as discussed
below. In these situations, the Agency
has elected not to revise inconsequential
data, particularly where it is not clear
which data are more accurate.
Some overall decisions on data
quality issues have also been made for
purposes of revising the database.
Regarding assigning values to reported
nondetects, we are assuming that
nondetected values were present at one-
half the detection limit We considered
assuming nondetected values were
present at the full detection limit, but
found in most cases no significant
difference in the MACT data analysis
results. It represents a judgment by the
Agency based on its experience that, for
assessing standards and risk, this more
conservative approach increases our
confidence that standards and risk are
appropriate and acceptable.
In addition, we are excluding data
from sources no longer burning
hazardous waste, as suggested by
several commenters on the proposed
rule. Although such data may well be
indicative of the capabilities of control
equipment and thus relevant, the
resulting database is still large enough
to ensure that potential final MACT
standards can be judged to be
achievable (or not as the case may be)
without including these more
controversial data. Regarding older
emissions data when more recent data
was available for a source, we are
considering all data sets for sources that
currently bum hazardous waste. Both
recent and old data are instructive in
assessing the capabilities of the control
equipment at these operating facilities.
Finally, we screened out so-called
"normal" emissions data from the
MACT analyses. Although doing so may
appear counterintuitive at first blush,
one must consider that facility
compliance will generally be based on
operating limits established during the
MACT performance test (except if
compliance is based on a continuous
emissions monitoring system (CEMS)).i
During these MACT performance tests,
sources will likely operate under the
same worst-case conditions as they did
during trial burns and Boiler and
Industrial Furnace (BIF) rule
certification of compliance testing.
Operating under worst-case conditions
with respect to emissions and operating
parameters gives operators a wide
allowable envelope of operating limits
needed to efficiently and economically
operate the combustor and yet maintain
compliance. Considering normal
emissions data in the MACT analysis
could inappropriately result in the
Agency establishing a MACT standard
based on normal emissions and
conditions while the source would be
operating under worst-case conditions
to demonstrate compliance. Thus,
emissions while complying with
operating limits would be
inappropriately constrained to below
current normal emission levels, even for
sources equipped with well-designed
and operated MACT floor control.
B. PM as a Surrogate for Non-Hg Metals
The Agency proposed a MACT PM
standard as a surrogate for non-D/F
organic HAPs (that are adsorbed onto
the PM) and for the metal HAPs not
individually regulated under the
proposed metal standards (i.e., Co, Mn,
Ni, and Se). See 61 FR at 17376.
Since proposal, the Agency has
reconsidered in the context of this joint
RCRA-CAA rulemaking whether a
MACT PM emission standard could
serve as a surrogate for six non-Hg metal
HAPs for which the Agency did propose
specific standards—semivolatiles (Cd
and Pb) and low volatiles (As, Be, Cr,
and Sb). This issue arises, in part,
because the risk assessment at proposal
on the MACT standards estimated that
the high-end individual lifetime cancer
risks using 90th percentile metal
emission levels were well below 10~6
for cement kilns and LWAKs. For
incinerators, the highest estimated
cancer risks exceeded 10-6 but were
below 10-5.9
To evaluate PM as a surrogate for non-
Hg metals in the context of this joint
RCRA-CAA rulemaking, questions that
must be addressed are: (1) Would a
MACT PM standard control the six-non-
Hg metals to MACT emission levels in
the special context of hazardous waste
combustors; and (2) would there be
significant health risk at MACT
emission levels that would have to be
addressed with RCRA controls (based at
least in part on site-specific risk
assessments using omnibus authority)?
Because, in the case of hazardous
waste combustors, there are significant
levels of metals in the hazardous waste-
derived fuel being burned, the Agency
has initially concluded that a MACT PM
emission standard in this particular rule
may not adequately control the six non-
Hg metals to the nominal MACT
emission levels. The residual risk that
could result from emissions of some of
the six non-Hg metals could be
significant10, and regulation of these
problematic metals under RCRA would
therefore be warranted. From an
implementation standpoint, this result
of mixed statutory controls is not
desirable. Although establishing six
additional specific limits on the non-Hg
metals eliminates this particular
implementation disadvantage, this
would add to the compliance and
implementation burdens on facility and
regulator alike. Consequently, it does
not currently appear appropriate to use
PM as a surrogate for all six toxic, non-
Hg metals.
In investigating this issue, however,
we determined that antimony (Sb), one
of the four low volatile metals, may not
warrant direct control. That is, the
MACT PM standard may serve as an
adequate surrogate for Sb to ensure that
it is not emitted at levels that pose a
health risk.'' We also considered
whether beryllium (Be), another LVM,
warranted control given that it is not
generally present in significant
concentrations in hazardous waste, and
baseline emissions of Be do not appear
to be posing a health hazard. Given that
Be is a toxic carcinogen, however, direct
MACT controls should be provided
even if current feedrates (and emission
rates) are low.
Only a preliminary analysis (see
discussion below) was used to
investigate whether some of the
'Note, however, that the example incinerators
modeled for the risk assessment had relatively tall
stacks which may not result in the higher ground
level concentrations (and thus higher direct
inhalation risk) that could result from small
incinerators.
10 This is at least partly because a PM control
device alone does not give the same targeted degree
of control for individual metals that a combination
of metal feed control plus a PM control device does.
11 Sb is a non-carcinogen with relatively low
toxicity compared with the other five non-Hg
metals, and would have to be present in hazardous
waste (and emitted PM) at extremely high levels
(perhaps over 1000 times the current levels) to pose
a health hazard. Current data suggest that metals
feedrates generally are either not increasing or
increasing at much lower rates.
-------
Federal Register / Vol. 62, No. 85 / Friday. May 2, 1997 / Proposed Rules 24217
remaining semivolatile and low volatile
metals—Cd, Pb, As, and Cr—may
warrant only indirect control through a
PM standard for any or all of the HWC
source categories. -We continue to •
believe that direct standards are
warranted for these four metals (either
individually or in volatility groups). For
purposes of public comment, we have
identified MACT standards for these
individual metals in case individual
standards are ultimately deemed more
appropriate than continuing to group
the metals by relative volatility.
However, we remain concerned about
the compliance and implementation
complexities that would be introduced.
(See the discussion below of revised
'SVM and LVM standards for each
source category.)
We solicit further comment on how to
ensure appropriate and effective control
of non-Hg metal HAPs while ensuring
that the regulatory scheme and
associated compliance elements are
implementable and not unnecessarily
burdensome. Some of the pertinent
issues are highlighted below for
commenter response.
1. Can PM serve as a surrogate for
SVM and LVM? A MACT PM standard
would provide MACT emissions control
technology (i.e., the air pollution control
device) for non-Hg metals. This is
because stack emissions of non-Hg
metals in combustion gases are
controlled by the PM control device.
Thus, MACT control (i.e., the emission
control device) for PM would also be
MACT control for non-Hg metals.
However, emissions of non-Hg metals
from HWCs are also controlled by the
feedrate of non-Hg metals (for kilns, the
feedrate of non-Hg metals in hazardous
waste) in addition to the PM control
device. Thus, a MACT PM standard
alone may not result in control of non-
Hg metals to MACT emissions levels
because emissions of non-Hg metals will
vary at a given PM level as feedrate
varies (i.e., emissions of non-Hg metals
will be a greater percentage of PM .
emitted as the feedrate rises).
Some commenters have argued that
PM is not a good surrogate for non-Hg
metals emissions. When sources (within
a source category) are considered in the
aggregate, a poor correlation between
PM and non-Hg metals emissions
.appears to exist. This is because sources
have various feedrates of the metals and
because different types of PM control
devices have different collection
efficiencies for these metals.12.13
Nonetheless, at a given source with a
given non-Hg metal feedrate, metal
emissions will correlate with PM .
emission levels. Although the
correlation will be different for more •
volatile versus less volatile metals,
emissions of these metals will increase
as PM emissions increase.
In summary, although there is a
correlation between PM and non-Hg «
metal emissions on a facility-specific
basis, and the MACT PM standard likely
would ensure use of MACT emission
control device for these metals, it may
not ensure attainment of MACT
emission levels of these metals. Given
the potential for HWCs to emit high
.levels of some of these metals, metal-
specific emission controls—MACT
standards—are warranted either
individually or in volatility groups.
2. Which non-Hg metals warrant
specific control by establishing MACT
emission standards? As an alternative to
establishing MACT standards for SVM
and LVM as proposed, we are re-
evaluating which non-Hg metals
warrant special control and whether to
establish individual MACT emission
standards for them.14 As discussed ^
above, our preliminary analysis
indicates that standards may not be
warranted for Sb. We are continuing to •
investigate whether any of the
remaining metals—As, Be, Cd, Cr, and
Pb—may not warrant direct emission
standards but may warrant only indirect
controls via the PM standard. Further,
. we are investigating how the metal ,.
standards should be structured: (1)
MACT standards for individual metals;
or (2) MACT standards for volatility
groupings (SVM and LVM) if we
determine, as currently contemplated,.
that direct standards for all five '
remaining metals are warranted (i.e., as
proposed).
For cement kilns and LWAKs, we
examined a comparison of potentially
allowable emission levels for non-Hg
metals under the BIF rule and actual
allowable (i.e., levels emitted during
Certificate of Compliance (CoC) testing)
emission levels. (Note that the actual
allowable levels are generally much
higher than normal emission levels
because sources spiked metals during
CoC testing.) A wide margin exists—
32 In addition, metal collection efficiency of the
PM control device varies at different metal
feedrates.
33 See, for example, comments submitted by
Chemical Manufacturers Association, RCRA Docket
SF-96-RCSP-FFFFF comment SRCSP-00128. •?
14 Other metal HAPs (other than Hg and the six
toxic metals covered at proposal) would be
controlled indirectly by the PM standard and any
individual or volatility group metal standards. Tljj^
is essentially unchanged from the proposal.
generally an order of magnitude or
greater—between BIF potentially
allowable emission levels and CoC
allowable emission levels. This means
that: (1) Cement kilns and LWAKs are
not emitting these metals at levels
posing a risk using BIF risk assessment
procedures; and (2) cement kilns and
LWAKs are feeding these metals at rates
well below those that would be allowed
under BIF risk-based limits and, thus,
indirect PM control under MACT may
similarly keep feedrates (and emission
rates) of these metals low.
We also examined data on the
percentage of emitted paniculate matter
that each non-Hg metal would have to
comprise to pose a health risk, assuming
BIF risk assessment procedures were
applied. Under this analysis, Pb and Sb
would have to comprise from 10-100
percent of emitted PM to pose a health
risk. Data suggest that these percentages
are not approached in today's
operations by a wide margin.
These preliminary analyses were
performed assuming BIF risk assessment
procedures. Thus, our evaluation may
not be representative of results that will
be forthcoming shortly using updated,
more detailed procedures for evaluating
risks under the final MACT standards.
For example, the risk assessment for this
rule considers indirect exposure (i.e.,
ingestion and food-chain uptake) while
BIF procedures consider only direct
inhalation. On the other hand, BIF
direct inhalation exposure assessment
procedures are more conservative (i.e.,
result in a higher estimate of risk) than
those that will be used for the final
MACT standards because the Agency
has revised those procedures in part to
consider more realistic exposure
scenarios. Nonetheless, the analyses
discussed above are viewed as
suggestive that regulation of each and
every semivolatile and low volatile
metal as proposed may not be
warranted.
We could not perform similar
preliminary analyses for incinerators
because we do not have dispersion .
coefficients readily available that would
be representative of the short stacks
used by many on-site incinerators.
However, a review of the emissions
database indicates that, as expected,
some incinerators—both commercial
arid on-site incinerators—emit much
higher levels of these metals than
cement kilns or LWAKs. Nonetheless,
we may find (as may be the case for
cement kilns and LWAKs) that Sb may
not warrant a direct metal-specific •
standard for incinerators as well, either
as part of the LVM group or an
individual standard.
-------
24218
Federal Register / Vol. 62, No. 85 / Friday,,May 2, 1997 / Proposed Rules
C. Options for Controlling Emissions of
Organic HAPs
Based on evaluation of the revised
emissions database, the Agency is
soliciting comment on options to
control emissions of organic HAPs by:
(1) Establishing MACT standards for
carbon monoxide (CO) and/or HC
emissions as surrogate indicators of
good combustion conditions;1S and (2)
ensuring that sources achieve 99.99
percent destruction and removal
efficiency ODRE).16 These options are
presented In Part Three:
Implementation, Sections n and HI,
because the DRE issue has
Implementation implications, and the
CO/HC issue relates to the DRE issue.
D. Accounting for Emissions Variability
In Establishing Emission Standards
At proposal, the Agency used a
statistical approach to identify an
emission level that MACT floor control
could achieve routinely considering that
the emissions database was comprised
of "short-term" test data. See 61FR at
17366. To identify an appropriate
standard, a computed variability factor
considering within-test condition
emissions variability was added to the
log-mean of the highest test condition
average for any source using floor
control. The log-mean of the runs for the
standard-setting test condition is the
"design level'—the emission level the
source would be designed to meet to
ensure emissions were less than the
standard 99 percent of the time,
assuming a source had average within-
test condition emissions variability
(average based on all sources using floor
control).
We are concerned that this computed
variability factor approach may be
Inappropriate in this particular
rulemaklng.17 For example, this
computed variability factor led to
illogical results for the PM standards for
Incinerators and LWAKs. In the case of
PM, the calculated standard using the
computed variability factor is 50 percent
higher than the current legally-
mandated RCRA PM limit for
Incinerators. For LWAKs, using the
"The Agency proposed to establish MACT
*ttnd*rds for both CO and HC but solicited
comment on whether a standard based on one
surrogate or the other may be sufficient. See 61 FR
•(17376.
"The Agency proposed to retain DRE as a RCRA
standard became of concerns that it would be
difficult to self-Implement under MACT
Implementation procedures. See 61 FR at 17447.
The Agency is reconsidering this issue and solicits
comment on alternative approaches to ensure
compliance with the DRE standard, including
incorporating DRE as a MACT standard.
"See. for example, proposed rule (61 FR at
17367).
variability factor results in a PM
standard of approximately 0.04 gr/dscf
(corresponding to a design level of 0.022
gr/dscf) nearly twice as high as any PM
emission value in the entire LWAK
database. Further, given that floor
control would be a fabric filter, our
engineering evaluationIs (and the
LWAK database itself) indicates that a
fabric filter can readily achieve levels.o£
0.022 or below, not the calculated 0.04.
These inappropriate and illogical
results may flow from either the
variability factor itself or the test
condition average identified as the
standard-setting test condition (to which
the variability factor is added). For
example, the variability factor itself
(which considers within-test conditions
emissions variability) could be
inappropriately high if there are outlier
runs within test conditions that are not
screened out. Although runs in many
test conditions appear to be outliers
(and analytical tests may show them to
be oudiers) it can be difficult to justify
screening them out unless there is a
specific technical explanation (e.g.,
unique design or operation feature or
inadequacy) that can be identified.
Unfortunately, this information is often
not available for many potential outlier
data.
As noted, identifying the standard-
setting test condition inappropriately
could be a factor. We have very limited
information on the design, operation,
and maintenance characteristics of the
emission control devices and
combustors. Accordingly, we have had
to define MACT floor control very
generically (e.g., ESP or fabric filter), as
discussed below, without attempting to
specify design, operation, and
maintenance characteristics.
Given these concerns and the statute's
direction to establish the maximum but.
achievable floor standard, we request
comment on an alternative approach to *•
account for emissions variability. This
alternative has two elements. First,
when a large data set from sources using
floor controlI9 exists,- the range of
emission levels from those sources
should adequately reflect emissions
variability. That is, a standard
established as the highest test condition
average for sources using floor control
represents an emission level that the
control technology is capable of
achieving, considering normal
variability in cpmbustor operations,
emission control device operations, and
test methods. Where these data show
that many sources using floor control
can achieve well below the standard,
this demonstrates that additional
emissions variability considerations are
not warranted. Source(s) with emission
levels close to the standard should be
. able to determine how to emit at levels
below the standard based on the specific
design, operation, and maintenance •
information available to them,
especially since many other sources
with the same basic equipment are
doing so.20 Second, where only a small
set of data from sources using floor
control exists, the range of emission
levels from these sources may be less
likely to reflect emissions variability. In
this case, consideration of an additional
variability factor (to be added to the
highest test condition average for a
MACT-control facility) may be
appropriate.
The impact of this alternative
approach has been examined. We do not
have a large data set in the expanded
universe for two standards: D/F
standards for incinerators equipped
with waste heat recovery boilers and D/
F standards for LWAKs. In each case,
we have data from only three sources,
and consequently floor control is based
on the suite of controls used by all three
sources.21 If the data set were large, we
would identify the floor level as the test
condition with the highest run average.
But, given the small data set, it is
reasonable from an engineering vantage
point to identity the standard as the
highest single run for the highest test
condition (when the unit was properly
operated).
We discuss below engineering and
data analysis methods and the resulting
standards for each HAP and source
category where a computed variability
factor is not used to establish emission
standards.
"See USEPA, "Draft Technical Support
Document for HWC MACT Standards (NODA),
Volume I: MACT Evaluations Based on Revised
Database", April 1997.
"Or, in the case of LWAKs, where the data set.
is essentially complete (i.e., where we have data
from all or most of the sources in the source
category).
20 No patterns in process design or operation in
the information we have explain why some sources
thought to be using floor control had significantly
higher emissions than other sources thought to be
using floor control. Where floor control is based on
an emission control device, these high emitters are
likely not in fact using floor controls—considering
the suite of design, operation, and maintenance'
factors that affect performance of the control
equipment but on which the Agency has no data.
Where floor control is based on finite control such
as combustion gas temperature or feedrate control,
the high emitters may be experiencing emissions
during the compliance test on the high end of the
range of emissions variability.
21 When data are available from fewer than 30
sources, MACT floor is defined as the median
emission limitation achieved by the best five
performing sources. Thus, the best performing three
sources (representing the median (and better
performers)) define MACT in this case.
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 7 Proposed Rules
24219
Finally, we are using an engineering
evaluation to identify a design level for
each standard for purposes of estimating
economic impacts and, for RCRA
purposes, the risk associated with the
design level for a given MACT standard.
The design level is the emission level to
which the control equipment must be
designed to ensure compliance with the
standard. For the RCRA risk analysis of
the final MACT standards, we will
analyze risks under the more realistic
assumption that a source is emitting at
the design .level on average, rather than
right at the standard all of the time.
Based on discussions with several air
pollution control device vendors and
facility operators, a design level of 70
percent of the standard is deemed
appropriate because it is within the
range of reasonable values that may be
encountered—50 percent to 90 percent
To the extent that industry engineering
experience suggest that a different
design level assumption would be more
typical and reasonable, we invite
commenters to provide that information.
We also considered whether the
design level as a percentage of the
standard (i.e., design factor) should vary
depending on whether the control is
finite (e.g., temperature control or
feedrate control) versus an emission
control device that is affected by various
parameters, or the type of emission
control device (e.g., metals controlled by
feedrate and an ESP or fabric filter).
However, we do not have enough
information to establish such tailored
and case-specific design factors. If
commenters supply sufficient
information, we will consider using this
approach.
As noted, we will use the design
factor to estimate costs of retrofitting for
all sources with emissions exceeding
the standard. For these sources, we will
estimate the costs of upgrading .emission
control equipment to meet the design.
leveL For sources using floor control
(i.e., sources in the expanded universe)
that have emissions greater than the
design level, however, we will not
attribute retrofit costs for compliance. T|
Given that these sources are using floor
control and that, as discussed above, the
large data set of sources using floor
control and meeting the floor standard
amply accounts for emissions ,
variability, we will presume that these
relatively high emissions for such floor-
controlled sources represent the high
end of the'range of emissions variability.
In other words, when these sources
retest emissions under the same
conditions, their emissions should meet
the standard.
E. Re-Evaluation of Proposed MACT
Standards for Incinerators
We discuss in this section the basis
for the revised standards for incinerators
that result from applying engineering
and data analysis to the revised
emissions database. We also discuss
refinements to analytical approaches
used in the proposal for identifying
floor controls and levels.22 A
comparison of the originally proposed
and potentially revised standards for
existing and new sources is presented in
the table below:
TABLE H.E.—REVISED STANDARDS FOR EXISTING AND NEW INCINERATORS 1
HAP or HAP surrogate
D/F (ng TEQ/dscm) „
PM (gr/dscf) : ....
HCI/CI2 (pptnv)
CO (oomv) ,
HC (ppmv)
SVM (uo/dscm) „
LVM (uo/dscm)
Existing sources
Proposed
standard
0.20
50
.030
280
100
12
270
210.*
Revised
standard
0.20
40
0.015
75
100
10
100
55
New sources
Proposed
standard
0.20
50
0.030
67
'100
12 .
62
60
. Revised
standard
0.20
40
0.015
75
100
. 10
100
55
. i All emission levels are corrected to 7% O2.
1. Subcategorlzation considerations..
Since proposal, the Agency has refined
potential options for subdividing the
incinerator source category to determine
if subdivided standards would be
appropriate: (1) Small23 versus large
sources; (2) commercial versus on-site
sources; and (3) small on-site sources
versus large on-site and commercial
sources. In large part, commenters
believed that small, on-site incinerators
should have less stringent standards to
reduce costs of compliance. However,
given that our analysis shows that the
revised standards for the small on-site
22 Additional details of the engineering and data
analysis evaluations performed on the revised
emissions database can be found in the Agency's
background document: USEPA, "Draft Technical
Support Document for HWC MACT Standards
(NODA), Volume I: MACT Evaluations Based on
Revised Database", April 1997.
23 An analysis of gas flowrates in actual cubic feet
per minute (ACFM) indicated that a maximum
sources would either remain the same or
be more stringent under these options,
we continue to believe that subdividing
would be inappropriate.24
We also received comments from the
US Department of Energy (DOE)
suggesting that DOE's mixed waste 2S
incinerators had several unique features
(discussed below) that would warrant
subcategorization.26 We are
investigating whether DOE's
incinerators pose unique
implementation and compliance
problems and therefore are considering
several options for the final rule: (1) no
flowrate of 20,000 acfm would be within the range
of values that could be selected to designate small
versus medium incinerators. We performed a
similar analysis at proposal and selected a flowrate
of 23,127 to designate small incinerators. See 61 FR
at 17372.
. 21 The Agency requested at proposal comments
on other means of reducing costs to small, on-site
incinerators (e.g.. waiving requirements for CEMS).
• "
subcategorization; (2) subcategorization
for mixed waste incinerators; and (3)
deferral of MACT regulation for mixed
waste incinerators (with RCRA rules
continuing to apply).
Under the No Suhcategorization
Option, we would find that the MACT
controls and emission standards
applicable to other incinerators are
appropriate for DOE's mixed waste
incinerators. Under this option we
could still define special compliance
requirements that account for any
unique features of mixed waste
incinerators.
We will consider all submitted comments on
options to reduce costs on these units In the final
rule.
23 Mixture of low level radioactive waste and
hazardous waste.
zsSee summary of DOE/EPA meeting at RCRA
Docket # F-96-RCSP-FFFFF item # S00270.
-------
24220
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
Under the Subcategorlzation Option,
we would find that because of unique
design or operating features, the MACT
controls or emission standards
identified for other incinerators are not
appropriate for mixed waste
incinerators. MACT standards unique to
these incinerators would be developed,
and special compliance requirements
could be defined.
Under the Deferral Option, we would
'determine that we do not have the
resources to make an appropriate MACT
determination on mixed waste
incinerators in time to meet the
schedule for the HWC rulemaking (i.e.,
the Phase I rule establishing MACT
standards for incinerators, cement kilns,
and LWAKs). Regulation of mixed waste
Incinerators would be deferred to the
Phase II rule where the Agency will
establish MACT standards for hazardous
waste burning boilers, halogen add
furnaces, and sulfur recovery furnaces.
The RCRA rules which now apply
would continue to do so.
DOE suggests that its mixed waste
Incinerators have several unique
features that would require ,
subcategorization and special
compliance standards:
• Each of DOE's four conventional
incinerators meet the Agency's
definition of small incinerators (i.e.,
<20,000 acfm gas flow rate), and one is
batch-operated only once or twice a year
with a gas flow rate of 3,000 acfm.
• Several mixed waste thermal
treatment units meeting the Agency's
definition of an incinerator are small
vitrification devices designed to process
metal bearing wastes and feed wastes
with extremely low organic content.
* Given that most of the mixed waste
Incinerators are very small units, a
mass-based emission limit would be
more appropriate than a concentration-
based emission limit.
• Approximately 95 percent of the
mixed waste that is Incinerated is
"legacy waste" generated during
production of nuclear weapons from
1943 until 1989 and may contain high
levels of mercury that cannot be
lowered by source reduction.
• Control of mercury emissions using
activated carbon Injection (ACI) would
be problematic because the spent carbon
would be a mixed waste, and if it
contained more than 260 ppm of
mercury, mercury retorting would be
required under the Agency's land
disposal restrictions even though there
are no retorters in the country that
manage mixed waste (and so a variance
would have to be obtained under
§268.44).
• Given that CEMS are not yet •
demonstrated for multi-metals (and a
CEMS requirement for mercury alone is •
also problematic for the final Phase I
rule), compliance with MACT metal
emission limits would be based on
feedrate limits for metals in feedstreams,
a potentially unworkable approach for
mixed waste since sampling and
analysis of radioactive feedstreams
raises serious human health concerns.
• DOE has negotiated plans and
agreements with States under Site
Cleanup Agreements mandated by
RCRA section 3021 (b) and CERCLA
section 120(e), and such plans and '
agreements would probably require
renegotiation (and delay) to comply
with the proposed MACT standards.
The Agency is continuing to
investigate these issues and will make a
determination regarding the appropriate
regulatory option in the final rule.
2. Dioxins andFurans (D/F) a. MACT
floor for existing sources. We proposed
a MACT floor standard of "0.20 ng TEQ/
dscm or gas temperature at the PM
control device <400°F" based on floor
control of temperature at the PM control
device. During subsequent analysis of
the revised database, we noticed again
that incinerators equipped with waste
heat boilers have significantly higher D/
F emissions than other incinerators. ^
This is likely because"the heat recovery.
boiler precludes rapid temperature
quench of combustion gases to a
temperature of <400°F (usually with a
wet scrubber), which would be floor
control for non-waste heat boilers. Floor
control for waste heat boilers would be
rapid quench of combustion gases at the
exit of the boiler to a temperature of
<400°F.
Based on the revised database, the
floor standard for waste heat boilers
would be "0.20, or 12 ng TEQ/dscm and
a temperature of<400°F at the PM
control device." Given that the waste
heat boiler expanded universe (i.e., the
entire database) is comprised of only
three sources, the highest single run for
the test condition with the highest run
average is a reasonable floor level. (Note
that if this were a large data set, we
would define the floor level simply as
the highest test condition average.) Thj?.
floor level is 50 percent higher than the
highest test condition average, and thus
appears to be a level that waste heat
boilers should be able to meet routinely
vising floor control.
The floor standard for non-waste heat
boilers would be "0.20, or 0.40 ng TEQ/
dscm and a temperature of <400°F at the
PM control device." This standard is
based on arraying emission levels for
sources using floor control and
screening out four test conditions with
anomalously high emissions. Three of
these test conditions were from sources
for which we had other test conditions
with emissions averages well below 0.40
ngTEQ.
We did not originally propose
separate standards for waste heat boilers
because the floor standard at proposal
was "0.20 ng TEQ/dscm or temperature
at the PM control device of <400°F."
Waste heat boilers could meet that
standard, and moreover, we proposed a
BTF standard of 0.20 ng TEQ/dscm for
all incinerators (a preference we do not
depart from in today's notice). Today,
however, we are presenting the option
of stating the standard in the form of a
TEQ level combined with a maximum
temperature at the PM control device.
This form of the standard is consistent
with the revised data, and would result
in somewhat lower emissions. This is
because, without the TEQ limit, some
sources could exceed that TEQ level at
the specified temperature.
b. BTF considerations for existing
sources. Incinerators can be equipped
with ACI at temperatures S400 °F to
achieve D/F levels below 0.20 ng TEQ/
dscm. Given the limited application of
the technology to control D/F emissions
from hazardous waste incinerators and
given that control efficiency is likely to
decrease at D/F emission levels below
0.20, a BTF standard of 0.20 ng TEQ/
dscm would continue to be appropriate.
See proposal for extended discussion,
61 FR at 17382.
Another option arising from the
refinement of our original analysis is to
establish a BTF standard for waste heat
boilers at "0.20, or 0.40 ng TEQ/dscm
and a temperature' of £400 °F at the PM
control device", and to remain at the •
floor standard for non-waste heat
boilers. These standards would ensure
that most, but not all, sources would
have emissions <0.20 ng TEQ/dscm.
Given that only a few sources would •
need to take additional measures to get
their emissions below 0.20, however, it
would be appropriate to establish a 0.20
BTF standard, assuming this level
remains appropriate after considering
statutory factors- for establishing
standards more stringent than the floor.
c. MAGT floor for new sources. At
proposal, we identified the same floor
control for new sources as for existing
sources: wet scrubbing and <400 °F at
' the PM device. This is because the
sources with the lowest emissions used
this control. In re-evaluating the
database for this NODA, however, an
engineering evaluation may be more
appropriate to identify ACI as floor
control because one source (i.e., the
single best controlled source) uses it
Even though most sources using rapid
quench by wet scrubbing can achieve D/
F levels less than 0.20 TEQ, some
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 /Proposed Rules
24221
sources using wet scrubbing have higher
D/F levels. ACI operated at 400 °F or
lower can universally achieve D/F levels
of 0.20 ng TEQ/dscm or less and is thus
the better performing technology. (Note
that waste heat boilers cannot use rapid
quench of combustion gases but can use
ACI.)
Although the source equipped with
ACI (Waste Technologies Industries) is
achieving D/F levels of 0.07 ng TEQ/
dscm, we believe that it is appropriate
to conclude that ACI can routinely
achieve a standard of 0.20 ng TEQ/dscm
given the limited application to date of
the technology for hazardous waste
incinerators and the uncertainties about
how much ACI control efficiency is
reduced at extremely low D/F emission
concentrations. However, we
specifically invite comment on the
potential levels that can be reached with
ACI, and on industry-wide achievability
of 0.07 ng TEQ/dscm as the floor for
new sources.
d. BTF considerations for hew
sources. At proposal, BTF for new
sources was based on performance of
ACI given that floor control was based
on performance of rapid quench. Under
today's analysis, MACT floor for new
sources would be based on ACI.
Although carbon beds would be able to
achieve lower emissions, they are not
thought to be cost-effective (particularly
if the floor for new sources was well
below 0.20 ng TEQ/dscm), and a BTF
standard would likely not be
appropriate.
3. Mercury (Hg). a. MACT floor for
existing sources. At proposal, the
, Agency identified floor control as either
(1) feedrate control of Hg at an
maximum theoretical emission
concentration (MTEC) not to exceed 19
(ig/dscm, or (2) wet scrubbing with
feedrate control of Hg at an MTEC not
to exceed 51 ng/dscm. We proposed a
floor standard of 130 jig/dscm.
Mercury emissions from incinerators.
are currently controlled by limiting the
feedrate of Hg combined with some
removal by air pollution control systems
(APCS). There are two APCS techniques
currently used by hazardous waste
incinerators (HWIs) to control Hg: wet
scrubbers and ACI. Although primarily
intended for acid gas control, nearly all
incinerators employ wet scrubbers that
capture the soluble forms of Hg species
(e.g., mercury salts). ACI is used by one
incinerator for control of Hg (and D/Fs).
The Agency also has data from one
additional facility using ACI; however,
these data were generated during a
demonstration testing program.
Review of the updated Hg data in the
revised database shows that feedrates
vary substantially. Generally the higher
feedrates are the result of Hg spiking.
We re-evaluated the revised database for
today's notice using a data analysis
. method similar to that used at proposal
to determine floor levels: (1) Rank Hg
emissions from lowest to highest; (2)
define as floor control the air pollution
control device (APCD) and associated
highest Hg MTEC for the 6 percent of
sources with the lowest emissions; and
(3) define as the floor standard the
highest test condition average emissions
of any test condition operated at or
below the Floor MTEC. Using the
revised database, MACT control would
be defined as wet scrubbing with a
MTEC of 50 ng/dscin, and the revised ^
floor standard would be 40 jig/dscm. *'
Nearly 60 percent of HWIs for which we
have data are achieving this level. t
b. BTF considerations for existing t
sources. The Agency originally
considered flue gas temperature
reduction to 400 °F or less followed by
ACI as the BTF option for improved Hg
control. As discussed at proposal, EPA
believes that ACI incinerator
applications can achieve Hg emission
reductions greater than 90 percent. In
the Notice of Proposed Rulemaking
(NPRM), the Agency proposed a BTF
standard of 50 ug/dscm.
As mentioned above for existing
sources, the Agency has in its database
Hg data from one facility (with two test
conditions) currently employing ACI as
a permanent application. Both test
conditions achieved Hg removal
efficiencies between 97 and 98 percent
at varying Hg feedrates. The Agency also
has data from a second facility
generated during a demonstration test
that show about a 98 percent ^
effectiveness at capturing Hg though at
one of the highest, feedrates in the
database. These data, in addition to ACI
applications on full-scale municipal
waste combustors and medical waste
incinerators,27 support the Agency's
assumption that ACI systems can
readily achieve capture efficiencies of
90 percent or more on incinerators.
In light of the revised database, EPA
can initially identify 4 ug/dscm as the
potential BTF standard based on ACI *
and flue gas temperature reduction to
400 °F or less. This is based on a source
achieving the floor level of 40 jig/dscm
and then applying ACI with a 90
percent removal efficiency. However, a
BTF level of 4 ng/dscm will likely raise
significant cost-effectiveness
considerations. Given that the floor
level discussed today would be
» USEPA. Section 5 of "Draft Technical Support
Document For HWC MACT Standards, Volume ffl:
Selection of Proposed MACT Standards and *tf
Technologies," February. 1996.
substantially lower than the proposed
floor, a BTF standard of 4 fig/dscm
would be less cost-effective than the
BTF levels of 30 ng/dscm.and 5 jig/dscm
analyzed at proposal.
c. MACT floor for new sources. At
proposal, the floor control for new
sources was similar as for existing
sources: wet scrubbing with feedrate
control of Hg at an MTEC not to exceed
51 ug/dscm. We proposed a floor
standard of 115 ug/dscm.
As discussed for existing sources,
both wet scrubbing and ACI are used for
Hg control. The single best performing
source for Hg control in our database,
measured by lowest emissions, is a wet
scrubber with Hg feedrate, expressed as
a MTEC, of 50 ug/dscm. Since MACT for
new HWIs is identical to MACT for
existing sources, analysis of emissions •
using these or better controls would
result in a floor level for new .HWIs of
40 ug/dscm.
The Agency also considered a MACT
floor based on ACI, a technology more
effective at Hg control than typical wet
scrubbing applications. The three test
conditions in the database indicate that*
ACI was effective in removing over 97
percent of Hg. However, the Hg feedrate
during the single best ACI test condition
was higher than the feedrate associated
with the single best performing wet
scrubber. In fact, Hg feedrates during the
ACI test conditions ranged from 5 to 300
times greater than the wet scrubber
MTEC level. To determine an emissions
level that ACI could routinely achieve,
we applied a capture efficiency of 90
percent to a Hg MTEC of 500 ng/dscm,
a typical feedrate identified, by a MTEC
breakpoint analysis. Thus, using the
revised database, the floor level for the
ACI evaluation would be 50 ug/dscm
which is slightly higher than the wet
scrubber floor analysis. The floor for
new sources based on the wet scrubber
evaluation appears to be more
appropriate because the floor level for
new sources should be at least as
stringent as for existing sources.
d. BTF considerations for new
sources. At proposal, BTF for new
sources was based on ACI. Similar to
existing sources, the Agency re-
considered the use of ACI as the BTF
technology. We identified a level of 4
Hudson as a potential BTF standard for
new sources based on ACI and flue gas
temperature reduction to 400 °F or less.
As discussed for existing sources, this
BTF level based on ACI will likely raise
significant cost-effectiveness
considerations.
4. Paniculate Matter (PM). a. MACT
floor for existing sources. At proposal,
EPA defined floor control based on
either (1) a fabric filter with an air-to-.
-------
24222
Federal Register /, Vol. 62. No. 85 / Friday, May 2, 1997 / Proposed Rules
cloth ratio of 10 acfm/ft2, or (2) a venturi
scrubber used with an ionizing wet
scrubber (IWS). The resulting floor
level, which included a statistically-
derived variability factor, was 0.107 gr/
dscf. Since this level is higher than the
current federal standard of 0.08 gr/dscf,
the Agency identified the floor level as
0,08 gr/dscf.
Today, in light of the revised
database, EPA is taking comment on two
refined engineering and data analysis
methods to identify the PM MACT floor
for HWIs. The evaluation technique and
results from both analyses are presented
below.
For the first (and possibly EPA's
preferred) data method, EPA would use
the following steps to Identify the PM
floor level: (1) Identify all PM control
equipment currently in use within the
HWI source category, regardless of
measured performance; (2) Identify as
MACT control those PM APCD
applications used by at least 6 percent
of sources that could be expected to
routinely and consistently achieve
superior PM performance relative to all
control strategies considered; and (3)
Identify an emissions level that well-
designed, operated and maintained
MACT controls can readily achieve
based on generally-accepted technical
and engineering information.
Using this approach, MACT controls
would be fabric filter, IWS, and ESP.
Based on the revised database, EPA's
evaluation of the MACT floor
performance level readily achievable by
a well designed, operated and
maintained MACT control device (fabric
filter, IWS, ESP) is 0.015 gr/dscf. Note
that even though the PM MACT floor is
based on fabric filter, IWS and ESP
APCDs, a source is not required to
employ MACT floor control but rather
only achieve the standard.
Approximately 75 percent of sources
employing MACT (measured by
available test condition data) currently
arc achieving 0.015 gr/dscf. An
evaluation of the remaining PM data
exceeding 0.015 gr/dscf from sources
ostensibly employing MACT Indicate
that 20 to 40 percent of these data may
be inappropriate for Inclusion (e.g., an
Incinerator with multiple test
conditions well below and a few above
0.015 gr/dscf). Generally, over 50
percent of HWIs, regardless of the PM
control currently employed, are
currently achieving a 0.015 gr/dscf
level.
The second refined data evaluation
method EPA is considering for PM Floor
analysis is similar to the standard-
setting process applied at proposal. This
evaluation is a four-step process: (1)
Rank all PM emissions data and identify
the MACT floor controls used by the
best performing 6 percent of sources; (2)
develop the expanded universe to
include all sources employing MACT
control, without further characterizing
MACT control (e.g., air-to-cloth ratio of
the fabric filter, specific collection area
for an ESP) as done in the proposal
because of the absence of reliable
detailed design, operating, and
maintenance information in the
database; (3) for each PM test condition,
evaluate the corresponding SVM system
removal efficiency (SRE) and screen out
sources that have relatively poor SREs
(i.e., outliers above a breakpoint in the
data array), which are indicators of poor
design, operation, and maintenance
characteristics of the MACT controls at
the source; and (4) Identify the MACT
floor equal to the highest test condition
average of all test conditions in the PM
expanded universe.
Using this alternative evaluation
approach as applied to the revised
database, MACT would be based on any
of the following PM controls: (1) Fabric
filter, (2) IWS, (3) ESP, or (4) venturi
scrubber burning liquid low ash wastes.
The resultant MACT floor would be
0.029 gr/dscf. Over 70 percent of HWIs,
regardless of the PM control equipment
employed, are currently achieving this
level. A potential drawback of using this
second alternative evaluation technique
is that nearly 75 percent of the availably,
incinerator PM data do not have
corresponding SVM data such that a
SRE could be calculated. This impacts
our ability to identify and screen out
poorer performing MACT APCDs from
the expanded universe, a critical step in
evaluating an appropriate performance *
level achievable by MACT control. As a
result, this evaluation technique may
not be appropriately identifying a PM
floor level representative of MACT. For
these reasons, the first data method
evaluation appears to be more reliable">
and sound for the Agency's revised
database. The Agency requests
comments on the both data analysis
methods presented. • +
In the NPRM, the Agency proposed ,
that sources maintain continuous
compliance with the PM standard
through the use of a PM CEMS. A
decision whether to require incinerators
to install a PM CEMS will be made at
the completion of an on-going
demonstration testing program to
determine if at least one PM CEMS can
meet the proposed performance
specifications. Since the.floor standards
discussed above were based on manual
test method data, the Agency will re-
evaluate at the completion of the CEMS
testing program whether these PM floor
standards would be appropriate in the
event that the final rulemaking requires
continuous compliance with a PM •
CEMS. The Agency will notice the
results and conclusions of the
demonstration test program in the
docket for the HWC rule.
b. BTF considerations for existing
sources. In the NPRM, the Agency
proposed a BTF level of 0.030 gr/dscf
and solicited comment on an alternative
BTF level of 0.015 gr/dscf based on
Improved PM control.
Based on the revised database, we can
evaluate a reduced PM emissions level
lower than 0.015 gr/dscf as the BTF
standard (in conjunction with
corresponding BTF reductions in SVMs
and LVMs) for existing HWIs. This
would require an improved PM
collection technology such as the use of
more expensive bag material for fabric'
filters or increased plate area or power
input to an ESP. Given that the
alternative floor level analyses
presented today would .be substantially
lower than the proposed floor and BTF
levels, significant cost-effectiveness
considerations come into play and
suggest that a BTF standard may not
ultimately prove to be appropriate.
c. MACT floor for new'sources. At
proposal, the Agency defined floor
control as a fabric filter with an air-to-
cloth ratio of less than 3.8 acfrn/ft2. The
proposed floor level was 0.039 gr/dscf.
Based upon our-evaluation of the
revised database, the floor control and
emission level discussed above for
' existing sources would also appear to be
appropriate for new sources. If this
eventuates, then MACT floor control
would be a well-designed and properly
operated PM control device (e.g., fabric .
filter, IWS, or ESP), and the MACT floor
for new HWIs would be around 0.015
gr/dscf.
d. BTF considerations for new
sources. At proposal, EPA proposed the
same BTF standard of 0.030 gr/dscf
(based on improved PM control) as that
proposed for existing sources.
Today, given the cost-effectiveness
considerations discussed above for
existing sources, the Agency is inclined
to think that a BTF standard beyond a
PM floor level of 0.015 gr/dscf (and
corresponding BTF reductions for SVMs
and LVMs) would not ultimately prove
to be acceptable.
5. Semivolatile metals (SVM)
(cadmium and lead) a. MACT floor for
existing sources. At proposal, EPA
defined floor control as either (1) a
venturi scrubber with a MTEC not to
exceed 170 jig/dscm, (2) a combination
of an ESP and wet scrubber with a
MTEC not to exceed 5,800 ng/dscm, or
(3) a combination of venturi scrubber
and IWS with a MTEC less than 49,000
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2. 1997 / Proposed Rules
24223
ug/dscm. The proposed floor level was
270 jig/dscm.
HWIs use a combination of good PM
control and limiting hazardous waste
feedrates to control SVM emissions.
SVMs, which typically vaporize at
combustion chamber temperatures and
recondense onto small-size particulates
in the APCD, are controlled most
efficiently by technologies that are
effective at capturing fine PM. EPA's
revised database shows that SVM
emissions vary substantially from 2 to
nearly 30,000 ng/dscm.
The refined data analysis method
used by EPA to evaluate and identify a
MACT floor would be based directly on
the results from the PM floor analyses
discussed above. As mentioned there, a
floor of 0.015 gr/dscf would appear to
represent the MACT floor for HWIs
based on good PM control. Since SVMs
are controlled, in part, by a well-
designed and operated PM control
devices, it follows that sources
achieving this PM performance level at
typical SVM feedrates should also be
controlling SVMs emissions.
Therefore, in its refined SVM analyses
of the revised database, the Agency first
considers all SVM data when
corresponding PM measurements are.
below 0.015 gr/dscf. To identify the
SVM floor from these data, we would
determine either the highest SVM test
condition average or the level that
excludes sources achieving substantially
poorer SVM control than the majority of
sources. It is most likely appropriate to
. use the latter approach—excluding
sources with significantly poorer SVM
performance—because their higher SVM
emissions may be the result of
exceedingly high SVM feedrates or some
other factor that cannot be readily
identified with available information
(e.g., sampling or analysis anomalies).
An SVM emissions breakpoint analysis
is the approach for excluding these
poorer performing test conditions.
Applying this evaluation technique to
the revised HWI SVM database results
in a MACT floor of 100 ng/dscm.
Approximately 53 percent of all HWI
SVM test condition data, regardless of
PM emissions level, are currently
achieving this emissions level.
As discussed above for PM, the
Agency is soliciting comment on an
alternative evaluation of the HWI PM
data which identified a floor of 0.029 gr/
dscf. Conducting the same SVM floor
analysis discussed above when PM
measurements were below 0.029 gr/dscf
also results in the same floor of 240 ng/
dscm. Approximately 60 percent of all
HWI SVM test condition data, regardless
of PM emissions level, are currently
achieving this emissions level.
Finally, as discussed in an earlier
section, a preliminary analysis indicates
that MACT standards may not be
warranted for one HAP metal, antimony.
Since the number of metals being
considered for MACT standards may
change, we are investigating the
appropriate structure of metals
standards (e.g., retain the volatility
groups or establish individual metals
standards). Using the refined method
discussed above for SVM, we analyzed
the revised database with respect to Cd
and Pb data. The floor analysis
corresponding to PM measurements
below 0.015 gr/dscf would result in the
following floor levels: Cd 20 pg/dscm,
and Pb 95 ng/dscm. The alternative data
analysis method for individual metals
when corresponding PM measurement?
were below 0.029 gr/dscf would result
in the following floor levels: Cd 57 ng/
dscm, and Pb 95 ng/dscm.
b. BTF considerations for existing
sources. In the NPRM, the Agency
considered a BTF standard for SVMs
based on improved PM control below
0.030 gr/dscf. However, the Agency
concluded that a BTF standard would
not be cost-effective given that the floor
level alone would result in an estimated
94 percent SVM reduction in emissions.
As discussed for PM 'BTF
considerations, we also re-evaluated the
possible appropriateness of using a
reduced PM emissions level based on
improved PM control as a BTF standard
(taking into consideration
corresponding BTF reductions in SVMs)
for existing HWIs. Given that the
alternative PM floor level analyses
presented today would be lower than
the proposed floor and BTF floor levels,
significant cost-effectiveness
considerations emerge and suggest that
a BTF standard for either SVMs or
individual Pb or Cd standards based on
improved PM control may not
ultimately prove to be cost-effective.
If, however, the revised risk
assessment yet to be conducted would
show significant risk at a SVM floor
standard of either 100 ug/dscm or 240
Hg/dscm, which are floor levels from the
two data analysis methods discussed -*:
above, the Agency will determine
whether a BTF standard based on
control of SVM feedrate to levels below
those at the floor would be appropriate.
This feedrate limitation would in turn
reduce SVM emissions. The BTF
standard and the corresponding level of
feedrate control would be dictated by
considerations of cost-effectiveness and
the need to establish more stringent
RCRA-related controls.
c. MACT floor for new sources. At
proposal, the Agency defined floor
control, based on the best performing
source, as a combination of venturi
scrubber and IWS with a MTEC less
than 49,000 jig/dscm. The proposed
floor level for new HWIs was 240 ng/
dscm.
Based upon our re-evaluation of the
database, the floor control and emission
level discussed above for existing
sources for PM and SVMs would also
appear to be appropriate for new
sources. In this event, MACT floor
control would be a well-designed,
operated and maintained PM control
device (e.g., fabric filter, IWS, or ESP)
achieving the PM floor level of 0.015 gr/
dscf, and the MACT floor would be
around 100 ug/dscm.
As discussed above, the Agency is .
soliciting comment on an alternative
evaluation of the revised SVM database
which concludes that MACT floor
control is a well designed, operated and
maintained PM control device (i.e.,
fabric filter, IWS, or ESP) achieving a
PM level of 0.029 gr/dscf. The floor
analysis considering all revised SVM
data when corresponding PM
measurements are below 0.029 gr/dscf
results in a floor for new sources of 240
ug/dscm.
Finally, we have evaluated what
individual metal floor levels for new
sources would be. When PM
measurements are below 0.015 gr/dscf,
the analysis would result in floor levels
for Cd of 20 ug/dscm and for Pb 95 ng/
dscm. Under the alternative data
analysis method for individual metals
when PM measurements were below
0.029 gr/dscf, floor levels would be 57
ug/dscm for Cd and 95 ug/dscm for Pb.
d. BTF considerations for new
sources. In the NPRM, the Agency .
proposed a BTF level of 62 ug/dscm
based on improved PM control below
0.030 gr/dscf.
As discussed for PM, a reduced PM
emissions level based on improved PM
control could be considered in
evaluating a potential BTF standard
(considering corresponding BTF
reductions in SVMs and LVMs) for new
HWIs. Because the PM floor level
presented today would be substantially
lower than the proposed floor and
proposed BTF floor level, cost-
effectiveness issues are again raised and
suggest that a BTF standard for either
SVMs or individual Pb or Cd standards
based on improved PM control may
likewise ultimately prove to be
inappropriate.
6. Low volatile metals (LVM) (arsenic,
beryllium, and chromium), a. MACT
. Floor for Existing Sources. At proposal,
EPA defined floor control as either (1)
a venturi scrubber with a MTEC not to
exceed 1,000 ug/dscm, or (2) an IWS
with a MTEC less than 6,200 ug/dscm.
-------
24224
Federal Register / Vol. 62, No. 85 / Friday. May 2, 1997 / Proposed Rides
The proposed floor level was 210 ug/
dscm, which Included antimony.
HWIs use a combination of good PM
control and limiting hazardous waste
feedrates to control LVM emissions.
LVMs are less likely to vaporize at
combustion temperatures and therefore
partition primarily to the residue or
adsorb onto particles in the combustion
gas. EPA's database shows that LVM
emissions from HWIs vary widely from
1 to over 130.000 ug/dscm.
To Identify a LVM MACT floor, the
Agency used the same data analysis
method applied to the revised SVM
database. As was determined in the PM
analysis of the revised database, a floor
of 0.015 gr/dscf represents MACT for
HWIs based on good PM control.
Considering all LVM data from sources
achieving a PM level 0.015 gr/dscf or
better, the Agency's evaluation of the
revised HWI data results In a LVM floor
of 55 ug/dscm (excluding sources above
a breakpoint and therefore achieving
substantially poorer LVM emissions
than the majority of sources). Over 70
percent of HWI LVM test condition data
are currently achieving this emissions
level.
As discussed earlier, the Agency is
soliciting comment on an alternative
. evaluation of the revised HWI PM data
which Identified a floor of 0.029 gr/dscf.
Evaluating the revised LVM data using
this method results in a LVM floor of
190 Ug/dscm. Approximately 90 percent
of HWI LVM test condition data are
currently achieving this level.
Finally, as discussed in an earlier
section, a preliminary analysis indicates
that MACT standards may not be
warranted for one HAP, antimony. Since
the number of metals being considered
for MACT standards may change, we are
Investigating the appropriate structure
of metals standards (e.g., retain the
volatility groups or establish individual
metals standards). Using the refined
method discussed above for LVM, we
analyzed the revised database with
respect to As. Be. and Cr (hexavalent).
The floor analysis corresponding to PM
measurements below 0.015 gr/dscf
results in the following floor levels: As
21 Ug/dscm, Be 2 ug/dscm. and Cr
(hexavalent) 3 ug/dscm. The alternative
data analysis method for individual
metals when corresponding PM
measurements were below 0.029 gr/dscf
results In the following Floor levels: As
21 ug/dscm, Be 2 ug/dscm, and Cr
(hexavalent) 5.5 ug/dscm.
The Agency Is concerned that some of
the potential floor standards for some
Individual metals (e.g., Be, Cr
(hexavalent)) may be present at levels
approaching practical quantitation
limits (PQLs). PQLs are the lowest level
of quantification that the Agency
believes a competent analytical •
laboratory can be expected to reliably «
achieve. The Agency will investigate *
whether this issue may need to be ,
addressed in the development of any
individual metals standards that may be
considered for the final rulemaking. We
invite comment on the issue of PQLs
and LVM BTF standards.
b. BTF considerations for existing
sources. In the NPRM, the Agency
considered a BTF standard for LVMs
based on improved PM control below
0.030 gr/dscf. However, the Agency
concluded .that a BTF standard would
not be cost-effective given that the floor
level alone would result in an estimated
91 percent LVM reduction in emissions.
As discussed for PM, a reduced PM
emissions level based on improved PM
control could be considered in
evaluating a potential BTF standard
(taking into consideration
corresponding BTF reductions in LVMs
and SVMs) for existing HWIs. Because
the PM floor level presented today
would be substantially lower than the
proposed floor and BTF floor levels, a
BTF standard for either LVMs or
individual As, Be, and Cr (hexavalent)
standards based on improved PM
control would raise significant cost- *i
effectiveness concerns and may not be
appropriate. ,
If, however, the revised risk
assessment yet to be conducted would
show significant risk at a LVM floor
standard of either 55 ug/dscm or 190 ug/
dscm, which are floor levels from the
two data analysis methods discussed
above, the Agency will determine
whether a BTF standard based on
control of LVM feedrate to levels below
those at the floor would be appropriate.
This feedrate limitation would in turn
reduce LVM emissions. The BTF
standard and the corresponding level of
feedrate control would be dictated by
considerations of cost-effectiveness and •
the need to establish more stringent ~*
RCRA-related controls.
c. MACT floor for new sources. At
proposal, the Agency defined floor
control, based on the best performing
source, as a venturi scrubber with a
MTEC less than 1,000 ug/dscm. The
proposed floor level for new HWIs was
260 ug/dscm.
Based upon our re-evaluation of the
database, the floor control and emission
level discussed above for existing
sources for PM and LVMs would also
appear to be appropriate for new
sources. MACT floor control is a well-
designed, operated and maintained PM
control device (e.g., fabric filter, IWS, or
ESP) achieving the PM floor level of
0.015 gr/dscf, and analysis of the
revised data results in a LVM MACT
floor of 55 jig/dscm.
As discussed above, the Agency is
• soliciting comment on an alternative
evaluation of the revised LVM database
which identifies MACT floor control as
a well-designed, operated and
maintained PM control device (e.g.,
fabric filter, IWS, or ESP) achieving a
PM level of 0.029 gr/dscf. The floor
analysis considering all revised LVM
data when corresponding PM
measurements are below 0.029 gr/dscf
results in a floor for new sources of 190
Ug/dscm.
Finally, individual metal floor levels
for new sources, when PM
measurements are below 0.015 gr/dscf,
are: As 21 ug/dscm, Be 2 ug/dscm, and
Cr (hexavalent) 3 ug/dscm. Under the
alternative data analysis method for
individual metals when PM
measurements are below 0.029 gr/dscf,
the floor levels are: As 21 ug/dscm, Be
2 ug/dscm, and Cr (hexavalent) 5.5 ug/
dscm. [Note: The same PQL concerns
would be present here as well.]
d. BTF considerations for new
sources. In the NPRM, the Agency
proposed a BTF level of 60 ug/dscm
based on improved PM control below
0.030 gr/dscf.
As discussed for PM BTF
considerations, the Agency considered a
reduced PM emissions level based on
improved PM control as the BTF
standard (taking into consideration
corresponding BTF reductions in LVMs
and SVMs) for new (and existing) HWIs.
Because the alternative PM floor level
presented today is substantially lower
than the proposed floor and BTF floor
levels, a BTF standard for either LVMs
or individual As, Be, or Cr (hexavalent)
standards based on improved PM
control may be inappropriate in light of
the cost-effectiveness issues inherent in
this scenario.
7. Hydrochloric Acid and Chlorine
(HC1/C12). a. MACT Floor for Existing
Sources. At proposal, the Agency
defined floor control as wet scrubbing
with a chlorine MTEC (i.e., maximum
theoretical emission concentration) up
to 2.1E7 "ug/dscm and proposed a floor
standard of 280 ppmv. While evaluating
the revised database, we investigated
another data analysis method whereby
floor control would be'defined as wet
scrubbing combined with chlorine
feedrate control to achieve an emission
level of 75 ppmv.zs Under this method,
28 Although a specific feedrate (i.e., MTEC) level
is not used to define MACT floor, feedrate control
is part of floor control to achieve the 75 ppmv
standard using wet scrubbing (i.e., a source would
probably not be able to feed chlorine at extremely
high rates and still achieve the standard using wet
scrubbing). Further, as discussed below in the text,'
-------
Federal Register / Vol. 62, No. 85 / Friday. May 2, 1997 / Proposed Rules
24225
emissions data from sources using wet
or dry scrubbing were arrayed from
lowest to highest (without explicit
regard to chlorine feedrate) and sources
achieving substantially poorer HC1/C12
control than other sources were
screened from the analysis.
Accordingly, after five of 48 test
conditions were screened from the
analysis for anomalously high emission
rates,29 the floor standard was
established as the highest remaining test
condition average—75 ppmv.30 Nearly
90 percent of test conditions31 in the
revised database have emission levels
below 75 ppmv.
• The Agency requests comment on
whether this alternative approach to
define floor control and a floor level
would be more appropriate than the
proposed approach.
b. BTF considerations for existing
sources. At proposal, the Agency
determined that a BTF standard would
not be warranted. Specifically, -the
Agency noted that risk from emissions
at the floor standard would not likely
trigger the need for additional control
under RCRA.
Although that may prove to be the
case as well for the alternative standard
discussed in today's notice (i.e., 75
ppmv), the risk assessment
accompanying the final rule will
consider incinerators with short stacks
and will also consider acute risk from
HC1 and C12 during short-term
exposures. The risk assessment at
proposal modeled emissions only from
incinerators with relatively tall stacks,
and did not consider acute exposure to
HC1 and C12. If, however, the revised
risk assessment yet to be conducted
shows significant risk at a floor standard
of 75 ppmv, the Agency will determine
whether a BTF standard would be
appropriate considering cost-
effectiveness of such a standard and the
need to establish more stringent controls
under RCRA. In that case, BTF control
could be based on a minimum system
removal efficiency (e.g., 99.9 percent)
and/or control of chlorine feedrate.
c. MACT floor for new sources. At
proposal, the Agency identified floor
control for new incinerators as wet
scrubbing with an MTEC of 1.7E7 ng/
dcsm See 61 FR at 17388. Although the ,
floor control for new sources was based
on the single best performing source and
was more stringent than floor control for
existing sources, the floor emission levej*
was the same for new and existing t
sources: 280 ppmv.
When evaluating the revised
emissions database considering various
data analyses methods for today's
notice, we determined that floor control
for new sources should be the same as
for existing sources: Wet scrubbing with
chlorine feedrate control to achieve an
emission level of 75 ppmv. This is state-
of-the-art control for these HAPs.
Accordingly, the floor standard for new
sources would be 75 ppmv under this .,
data analysis method. $.
d. BTF considerations for new
sources. The Agency proposed BTF "
control for new incinerators as 99
percent SRE and a BTF standard of 67
ppmv. This standard was based on
applying 99 percent reduction to the test
condition in the database with the
highest average emission without an
emission control device (i.e., 1100 '
ppmv). Then, considering other factors
including a computed emissions
variability factor, the Agency
determined that a BTF standard of 67
ppmv would be appropriate.
In retrospect, as we discussed above,
virtually all sources are already
equipped with some form of scrubber
and 90 percent are achieving emission
levels of 75 ppmv or below. Thus, this
would be an appropriate floor control
and standard for new sources. As
discussed above for existing sources, a
BTF standard appears to be
unnecessary, unless the upcoming final
risk analysis indicates that more
stringent controls under RCRA would be
warranted. A BTF standard could be
based on a minimum system removal
efficiency (e.g., 99.9 percent) and/or
control of chlorine feedrate.
8. Carbon Monoxide (CO). As
proposed, the Agency continues to
believe that floor control for CO (as a
surrogate for organic HAPs) for both
existing and new sources would be
operation under good combustion
practices. The preponderance of the.
revised emissions data indicate that a
sources with anomalously high emissions were
screened from consideration. One reason that a
source may have anomalously high emissions is
that it may be feeding unusually high levels of
chlorine.
29 The anomalously high emissions could have
been caused by: (1) Poor design, operation, or
maintenance of the scrubber, and thus the device
would not represent MACT (e.g., a dry scrubber was
screened from the analysis because dry scrubbers
are generally less efficient than wet scrubbers); (2)
unusually high chlorine feedrates: or (3) sampling
or analysis anomalies.
floor standard of 100 ppmv over an
hourly rolling average (HRA) would be
readily achievable. In addition, the
Agency continues to believe that a BTF
standard for CO based on better good
combustion practices is likely to raise
significant cost-effectiveness
considerations.
9. Hydrocarbons (HC). The Agency
proposed that floor control for HC (as a
surrogate for otherwise unaddressed
organic HAPs) for both existing and new
sources would be operated under good
combustion practices and that a floor
standard of 12 ppmv over an hourly
rolling average (HRA), would be
appropriate. In evaluating the revised
.emission database for today's notice, we
used the same general approach for HC
as at proposal—the entire database was
arrayed from the lowest to the highest
emission levels and assumed that test
conditions beyond a breakpoint were
not operated under good combustion
practices. Based on that analysis, a floor
level for HC of 10 ppmv, HRA, results.
(This 10 ppmv standard does not
include a variability factor for reasons
discussed above, unlike the proposed
standard of 12 ppmv that did.) Not only
does the revised database show that the
preponderance of the data are below 10
ppmv, but engineering experience and
other engineering information suggests
that a HC level of 10 ppmv is readily
achievable using good combustion
practices.
As discussed at proposal, the Agency
continues to be concerned about cost-
effectiveness considerations related to
BTF controls for HC based on operating
under better combustion practices..
F. Re-Evaluation of Proposed MACT
Standards for Cement Kilns
We discuss in this section the basis
for the revised standards for cement
kilns that result from applying
engineering and data analysis to the
revised emissions database.32 A
comparison of the proposed and
potentially revised standards for
existing and new sources is presented in
the table below:
30 The floor standard under this alternative
analysis method—75 ppmv—would be substantially
lower than the proposed floor standard—280
ppmv—even though feedrate control of chlorine $£.
would not be used explicitly to help define floor
control under this alternative method because, to
identify the proposed standard, the Agency: (1)
Selected as the standard-setting test condition the
highest test condition for sources appearing to be
using floor control without screening anomalous
test conditions; and (2) added a computed
emissions variability factor to emissions from that
standard-setting test condition.
31 Considering approximately 50 test conditions
where emissions levels on both HC1 and C12 were
available.
32 Additional details of the engineering and data
analysis evaluations performed on the revised
emissions database can be found in the Agency's
background document: USEPA, "Draft Technical
Support Document for HWC MACT Standards
(NODA), Volume I: MACT Evaluations Based on
Revised Database", April J997..
-------
24226
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
TABLE II.F.—REVISED STANDARDS FOR EXISTING AND NEW CEMENT KILNS
HAP or HAP Surrogate
D^F (ng TEQ/dscm)
Ho (ualdscm)
PM (grAJsd)
HCt/Ct2 (ppmv)
CO foomv)
HC (ppmv):
Main Stack2
By-Pass ..
SVM (ug/dscm) „
LVMfuo/dscrrt
Existing sources
Proposed
standard
'0.20
50
0.030
630
100
^
20
6.7
57
130
Revised
standard
0.20
72
0.030
120
100
20
10
670
63
New sources
Proposed
standard
0.20
50
0.030
67
100
20
6.7
55
44
Revised
standard
0.20
72
0.030
120
.100
20
10
670
63
1 All omission levels are corrected to 7% Oz.
2 Not appBcaWa to preheater and/or prccalciner kilns.
1. Subcategorizatton considerations.
After analyzing comments submitted by
the Cement Kiln Recycling Coalition
(CKRC) on the proposed rule, including
information on the types of cement kilns
that are currently burning hazardous
•waste, we considered whether the
following subcategories would be
appropriate: (1) Short kilns with
separate by-pass and main stacks; (2)
short kilns with a single stack that
handles both by-pass and preheater or
prccalciner emissions; (3) long dry kilns
that use kiln gas to dry raw meal in the
raw mill; and (4) others (i.e., wet kilns,
and long dry kilns not using raw mill
drying). Each of the first three categories
Js comprised of only one cement kiln
facility while the kilns at the remaining
19 facilities are in the fourth category:
wet kilns or long dry kilns that do not
use raw mill drying. We find that these
subcategories should be considered
because the unique design or operating
features of these kirns could have a*
significant Impact on emissions of one
or more HAPs that the Agency proposed
to regulate.
To determine whether special
standards would be appropriate for any
of the three unique cement kiln types,
we Identified floor control and emission
levels considering data only for the
other kilns (i.e., wet kilns, and long dry
kilns not using raw mill drying). We
then considered whether the unique
kiln types could apply the those MACT
controls and achieve those emission
standards. It appears that these unique
kilns can employ the MACT controls
and achieve the corresponding emission
levels Identified in today's notice for the
other kilns (i.e., wet kilns, and long dry
kilns not using raw mill drying). Thus,
subcategorizatlon would not appear to
be needed to determine achievable
MACT floors for all cement kilns
burning hazardous waste.
2. Dioxins andFurans (D/F). a. MACT
Floor for Existing Sources. At proposal,
the Agency identified floor control as
"temperature control at the inlet to the
ESP or fabric filter at 418 °F". The
proposed floor emission level was "0.20
ng TEQ/dscm, or temperature at the •
Inlet to the ESP or fabric filter not to
exceed 418 °F".
Upon re-evaluation of the revised
database^ we have identified an
alternative data analysis method that
seems more appropriate to identify floor
control and the floor emission level.
Based on an engineering evaluation of .
these data and other available •*
information, floor control would be
"temperature control at the inlet to the ,
ESP or fabric filter at 400 °F". This
results in a floor emission level of "0.20
ng TEQ/dscm, or 0.40 ng TEQ/dscm and
temperature at the inlet to the ESP or
fabric filter not to exceed 400 °F".33
Temperature control to 400 °F or
lower is appropriate for floor control
because, from an engineering
perspective, it is within the range of
reasonable values that could have been
selected considering that: (1) The
optimum temperature window for
surface-catalyzed D/F formation is 450-
750 °F; and (2) below 350 "F, kiln gas
can fall below the dew point which can
increase corrosion in ESPs and fabric
filters and reduce performance of the
control devices. In addition,
approximately 20 percent of the test
conditions in our revised database
reflect operations at temperatures of 400
33 The standard would be expressed in the form
of a TEQ level combined with a maximum
temperature at the PM oontrol'device. This form of
the standard is consistent with the revised data and
would result in somewhat lower emissions (i.e.,
because without the TEQ limit, some sources could
exceed that TEQ level at the specified temperature).
Thus, expressing the standard in this form better j^
achieves the statutory mandate to establish
standards that provide the maximum degree of
reduction that is achievable in practice.
°F or below. Thus, this temperature
level is readily achievable.
To identify an emission level that
terriperature control <400 °F could
achieve, it is appropriate to pool the
available emissions data for hazardous
waste burning kilns with data from
nonwaste burning kilns.34 This is
because we are not aware of an
engineering reason why hazardous
waste burning would affect emissions of
D/F. In fact, when the data sets are
evaluated separately, the highest
emitting HW cement kiln operating the
ESP or fabric filter at temperatures <400
°F had D/F emissions of 0.28 ng TEQ/
dscm. The highest emitting nonwaste
cement kiln operating at those
temperatures had D/F emissions of 0.37
ng TEQ/dscm. We believe that the
difference in emission levels is simply
a reflection of many design, operation,
and maintenance factors on which we
have little or no information, but which
could affect D/F emission levels. An
appropriate emission level associated
with that operating temperature for all
cement kilns would be 0.40 ng TEQ/
dscm. Thus, the floor standard would
be: "0.20 ng TEQ/dscm, or 0.40 ng TEQ/
dscm and temperature at the inlet to the
ESP or fabric filter not to exceed 400
op..
b. BTF considerations for existing .
sources. The Agency proposed a BTF
standard of 0.20 ng TEQ/dscm based on
ACI operated at a temperature of <400
34 We considered whether nonwaste cement kiln
emission data should be pooled with HW cement
kiln data for other HAPs and determined that
.emissions of other HAPs, except for PM, could be
affected by hazardous waste burning. For example,
hazardous waste can have higher levels of chlorine
and metals such as Pb. With respect to PM,
although it appears appropriate to pool the data
sets, the better-suited data analysis method is based
on tine New Source Performance Standard, not an
analysis of the emissions database. Thus, pooling of
data would not affect the standard derived from that
data analysis method. See discussion on the PM
standard in the text.
-------
Federal Register / Vol. 62, No. 85 / Friday. May 2, 1997 / Proposed Rules
24227
°F. We continue to believe that this BTF
standard is appropriate given the
concerns the Agency has expressed
about the risks posed by D/F emissions,
and the Hg reductions that ACI would
also provide. See 61 FR at 17392. Only
sources emitting between 0.20 and 0.40
ng TEQ/dscm with temperature control
alone would need to take further
measures to reduce D/F levels to 0.20 ng
under the BTF standard. Although these
sources could achieve D/F emission
levels well below 0.20 ng TEQ/dscm
using ACI (i.e., ACI removal efficiency
should be in the 95-99 percent range),
a 0.20 ng TEQ/dscm appears still to be
appropriate because it may allow some
sources to meet the standard more cost-
effectively by lowering gas temperatures
at the ESP or fabric filter below 400 °F.
Further, a BTF standard of 0.20 ng TEQ/
dscm would likely avoid the need to
provide further controls under RCRA
authority.
c. MACT floor for new sources. At
proposal, the Agency identified floor
control for new sources as "temperature
control at the inlet to the ESP or fabric
filter at 409 °F". The proposed floor
emission level was "0.20 ng TEQ/dscm,
or temperature at the inlet to the ESP or
fabric filter not to exceed 409 °F".
Upon evaluation of the revised
database, the floor control and emission
level discussed above for existing
sources would also be appropriate for
new sources (i.e., "temperature control
at the inlet to the ESP or fabric filter at
400 °F" corresponding to an emission
level of "0.20 ng TEQ/dscm, or 0.40 ng
TEQ/dscm and temperature at the inlet
to the ESP or fabric filter not to exceed
400 °F". This is because our engineering
evaluation of available information and
facility operating experience indicates
that the best controlled source is one
that is controlling temperature control at
the inlet to the fabric filter at 400 °F.
d. BTF considerations for new
sources. The Agency proposed ACI as
BTF control and a BTF standard of 0.20
ng TEQ/dscm. We continue to believe
that this BTF standard is appropriate for
new sources for the same reasons
discussed above in the context of
existing sources.
3. Mercury (Hg). a. MACT floor for
existing sources. At proposal, the
Agency identified floor control as
hazardous waste feedrate control not to
exceed an MTEC of 110 p.g/dscm. EPA
proposed a floor standard of 130 jig/
dscm.
All cement kilns employ either ESPs
and fabric filters for PM control.
However, since Hg is generally in the
vapor form in and downstream of the
combustion chamber, including the air
pollution control device, ESPs and
fabric filters do not achieve good
mercury control. Mercury emissions
from cement kilns are currently
controlled by the BIF rule which
establishes limits on the maximum
feedrate of Hg in total feedstreams (e.g.,
hazardous waste, raw materials, coal).
Thus, MACT is based on hazardous
waste feed control.
Review of the revised database
indicate that cement kilns only
infrequently conducted Hg spiking of
the hazardous wastes (contrary to the
Agency's initial information), and thus
the Hg content in the wastes during
testing is likely representative of the Hg
content during typical operations. The
revised data also show that raw ^
materials can represent a significant •
source Hg input to the kiln system.
Since cement kilns do not employ a ^
dedicated device capable of Hg control,
the Agency believes that the Hg data are
essentially "normal" even though
generated during worst case compliance
testing conditions for other parameters^-
To evaluate these revised data for the
purpose of determining a MACT floor,
the Agency used the following data
analysis steps: (1) Rank Hg emissions
from lowest to highest; (2) conduct a
breakpoint analysis on the ranked Hg
emissions data, and (3) establish the
floor standard as the test condition
average of the breakpoint source. The .
breakpoint analysis reflects an
engineering-based evaluation of the data
and ensures that the few cement kilns
spiking extra Hg do not drive the floor
-level to levels higher than the
preponderance of this "normal" data
indicates is routinely achievable. The
Agency's analysis results in a MACT
floor level of 72 jig/dscm. The revised
database indicates that approximately
80 percent of cement kilns are achieving
this floor level.
b. BTF considerations for existing
sources. The Agency proposed a BTF
standard of 50 ng/dscm based on flue
gas temperature reduction to 400 °F or
less followed by ACI. EPA continues to
believe that ACI is an appropriate BTF
technology for cement kilns. Although
ACI is not employed for Hg control at
any full-scale HW cement kiln, the
Agency is not aware of any cement kiln^
flue gas conditions that would precludB
the applicability of ACI—which has
been demonstrated for other similar
types of combustion applications. As -.
discussed in the NPRM, EPA assumes :
that cement kilns employing ACI to
meet a BTF standard would install the
ACI system after the existing ESP or
fabric filter, and then add on a new
fabric filter to remove the injected
carbon with the adsorbed Hg. Although
adding a new fabric filter in series is an
expensive approach, it will enable
cement kilns to continue current cement
kiln dust (CKD) recycling practices by
avoiding potential internal build-up of
Hg from CKD recycling.
In the NPRM, the cement kiln BTF
standard was based on the assumption
that an ACI system could routinely
achieve Hg emissions reductions of 80
to 90 percent. The Agency received
public comments from, among others,
the cement manufacturing industry
questioning whether a ACI application
on a cement kiln could routinely
achieve capture efficiencies as
proposed. The commenters went on to
say that removal efficiencies of
approximately 60 percent were perhaps
more realistic. We will address these
comments specifically as part in the
final rulemaking, but for the purposes of
.today's analysis, EPA has assumed an
ACI effectiveness of 60 percent in
identifying BTF levels for cement kilns.
Thus, the BTF standard for cement kilns
would be 30 (ig/dscm based on an ACI
efficiency of 60 percent applied to the
potential floor level of 72 (xg/dscm.
Ultimately adopting a BTF standard of
30 |ig/dscm for cement kilns will likely
involve close scrutiny of cost-
effectiveness and other factors,
including the costs of retrofits that
sources will need to undertake (e.g.,
installing the ACI system, add-on of a
new fabric filter, managing the captured
carbon) relative to the emissions
reductions achieved. Without pre-
judging this issue, the Agency's
experience to date suggests that the final
analysis may well reveal significant
drawbacks associated with the BTF
level.
c. MACT floor for new sources. At
proposal, the Agency identified floor
control for new sources as hazardous
waste feedrate control not to exceed an
MTEC of 28 ug/dscm. EPA proposed a
floor standard of 82 ug/dscm.
The Agency believes that the floor
control and emission level discussed
above for existing sources would also be
appropriate for new sources. Thus, the
MACT floor for new cement kilns would
be 72 (ig/dscm based on the revised
database.
d. BTF considerations for new
• sources. At proposal, BTF for new
sources was based on ACI and we
proposed a BTF standard of 50 ug/dscm.
As discussed for existing sources, the
Agency is considering the use of ACI
and flue gas temperature reduction to
400 °F as the BTF technology. In ..
evaluating the revised database, EPA
has identified a level of 30 ug/dscm as
the BTF standard for new sources based
on ACI. This is based on a source
achieving the MACT new floor level of
-------
24228
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
72 ng/dscm and then applying ACI with
a 60 percent removal efficiency. For the
same reasons identified for existing
sources, the Agency is concerned about
whether this BTF level based on ACI
will ultimately prove to be cost-effective
for new cement kiln sources.
4. Paniculate Matter (PM). a. MACT
floor for existing sources. At proposal,
EPA defined floor control as a fabric
filter with an air-to-cloth ratio of 2.3
acfm/ft2. The floor analysis led to a level
of 0.065 gr/dscf, but due to concerns
with the appropriateness of using a
statistically-derived variability factor,
the Agency instead established the floor
standard based on the cement kiln New
Source Performance Standard (NSPS).
The NSPS is a process emissions rate
that converts to an approximate flue gas
concentration of 0.03 gr/dscf.
Today, EPA is taking comment on two
data analysis methods to identify the
PM floor standard for cement kilns. The
first data analysis method would be to
establish the floor standard equivalent
to the NSPS. which is 0.3 Ibs PM per ton
of dry raw material feed. Currently,
approximately 20 percent of HW cement
kilns are subject to the NSPS. Cement
kilns achieve the NSPS with well-
designed and properly operated ESPs or
fabric filters.
A second data analysis method
considered and potentially preferred
would be to express the NSPS as a stack
gas concentration limit as done in the
NPJRM. The conversion of the NSPS to
& concentration standard will vary by
kiln process type (e.g., wet, dry,
preheater, preheater/precalciner)
because the amount of flue gas
generated per ton of raw material feed
varies by process type. Based on typical
factors of flue gas quantities generated
per ton of raw material feed and flue gas
moisture content, the NSPS equates to a
PM concentration of approximately 0.03
gr/dscf for wet process kilns (also the
least energy efficient) and 0.05 gr/dscf
for preheater kilns (the most energy
efficient). The total HW cement kiln
universe is comprised of 41 kilns with
varying process types: 27 wet, 12 long
dry, one preheater/precalciner, and one
preheater. Of the cement kilns currently
subject to the NSPS standard, four are
wet, two are long dry, one preheater/
precalclner, and one preheater.
Notwithstanding that the
concentration equivalent of the NSPS
can vary by process type, establishing
the floor standard for all cement kilns at
0.030 gr/dscf appears to be appropriate
regardless of manufacturing process
utilized, for the following reasons: (1)
The majority (66 percent) of the cement
kilns are wet process kilns for which the
NSPS concentration equivalent is 0.030
gr/dscf. For these kilns, this floor
method would not differ from the initial
NSPS method used in the proposal. (2)
Our database shows non-wet process «
kilns have at least one test condition (in
addition to three quarters of all non-wet
process kiln data) achieving 0.030 gr/
dscf. Therefore, achievability of the
floor appears to be satisfied. (3) Even
though wet process kilns typically have .
lower inlet grain loadings than the non-
wet processes, non-wet kilns are
achieving the 0.030 gr/dscf level. Again,
the achievability requirement is met ,
Thus, the Agency believes that it is ^
appropriate to establish the MACT floor
for existing sources at 0.030 gr/dscf.
•In the NPRM, the Agency proposed
that sources maintain continuous
compliance with the PM standard
through the use of a PM CEMS. A
decision whether to require cement
kilns to install a PM CEMS will be made
at the completion of an on-going
demonstration testing program to
determine if at least one PM CEMS can
meet the proposed performance
specifications. Since the floor standards
discussed above were based on manual
test method data, the Agency will re-
evaluate at the completion of the CEMS
testing program whether these PM floor
standards would be appropriate in the
event that the final rulemaking requires
continuous compliance with a PM
CEMS. The Agency will make available
the results and conclusions of the
demonstration test program in the
docket for the H WC rule.
b. BTF considerations for existing
sources. In the NPRM, the Agency &
considered a BTF level of 0.015 gr/dscf
based on improved PM control.
However, we determined that such a
standard would not likely be cost-
effective. We did not have adequate data
to ensure that, given the high inlet grain
loading caused by entrained raw
material, cement kilns could routinely
achieve 0.015 gr/dscf arid below with a
single fabric filter or ESP.
In light of the revised database, the
Agency again considered a BTF PM
emissions level based on improved PM
control. Because the floor level of 0.030'
gr/dscf presented today is the same as
the proposed floor, a BTF standard
lower than 0.030 gr/dscf (even with
corresponding BTF reductions for SVMs
and LVMs) appears not to be cost-
effective based on information
developed at proposal.
,c. MACT floor for new sources. At
proposal, the Agency defined floor
control as a fabric filter with an air-to-
cloth ratio of less than 1.8 acfm/ft2. The
floor analysis lead to a level of 0.065 gr/
dscf. Due to concerns with the
appropriateness of the statistically-
• derived variability factor, the Agency
instead established the floor standard
based on the cement kiln NSPS. The
NSPS is a process emissions rate that , •
the Agency converted to an approximate
flue gas concentration of 0.030 gr/dscf.
Upon evaluation of the revised
database discussed for existing sources,
EPA continues to believe that the floor
standard discussed above for existing
sources would also be appropriate for
new sources. Therefore, MACT floor-
control is a well-designed and properly
operated PM control device (e.g., fabric
filter, ESP), and the MACT floor for new
cement kilns would be 0.030 gr/dscf.
d. BTF considerations for new
sources. In the NPRM, EPA considered
a BTF standard based on improved PM
control to be consistent with existing
sources. However, we found that the
BTF level would not be cost-effective.
Today, as discussed above for existing
source BTF considerations and based
upon examining the revised database in
light of the findings at proposal, a BTF
standard beyond a PM level of 0.030 gr/
dscf (and corresponding BTF reductions
for SVMs and LVMs) would not appear
to be cost-effective.
5. Semivolatile Metals (SVM)
(cadmium and lead), a. MACT Floor for
Existing Sources. At proposal, EPA
defined floor control as a fabric filter
with an air-to-cloth ratio less than 2.1
acfm/ft? and a HW MTEC of 84,000 ng/
dscm. The proposed floor level was 57
Hg/dscm.
Cement kilns use a combination of
good PM control and limiting hazardous
waste feedrates to control SVM
emissions. SVMs are controlled most
efficieritiy by technologies, such as
fabric filters, which are effective at
capturing fine PM. EPA's database
shows that SVM emissions vary
substantially from 1 to over 6,000 ng/
dscm.
The engineering evaluation and data
analysis method used by EPA to
evaluate and identify a MACT floor
from the revised database is an
.extension of the PM floor analyses of the
revised database. As discussed in the
PM analysis, a floor of 0.030 gr/dscf
could represent MACT based on good
PM control. Since SVMs are controlled,
in part, by a well-designed and operated
PM control device, it follows that
sources achieving this PM performance
level should also be controlling SVM
emissions at typical SVM feedrates.
Therefore, in its refined SVM analysis of
the revised database, EPA would first
consider all SVM-data when
corresponding PM measurements are
below 0.030 gr/dscf. To identify the
SVM floor from these data, we would
identify the floor at the level that
-------
Federal Renter / Vol. 62, No. 85 / Friday, May 2. 1997 / Proposed Rules
24229
excludes (by breakpoint analysis)
sources achieving substantially poorer
SVM control than the majority of
sources. As noted earlier in the case of
HWIs, it is appropriate to exclude
sources with significantly poorer SVM
performance because their higher SVM
emissions may be the result of
exceedingly high SVM feedrates or some
other factor that shows the test
condition did not actually reflect MACT
floor controls. The Agency does not
have available information to otherwise
screen out these non-MACT test
conditions from the expanded universe
for SVM.
The Agency's evaluation of the
revised cement kiln SVMs data results
in a MACT floor of approximately 670
pg/dscm. Approximately 85 percent of
SVM test condition data are currently
achieving this emissions level.
Finally, as discussed in an earlier
section, a preliminary analysis indicates
that MACT standards may not be
warranted for one HAP metal; antimony.
Since the number of metals being
considered for MACT standards may
change, we are investigating the
appropriate structure of metals
standards (e.g., retain the volatility
groups or establish individual metals
standards). Using the refined method
discussed above for SVM, we analyzed
the revised database with respect to Cd
and Pb data. The floor analysis
corresponding to PM measurements
below 0.030 gr/dscf would result in the
following floor levels: Cd 60 pg/dscm,
and Pb 560 pg/dscm.
b. BTF considerations for existing
sources. In the NPRM, the Agency
considered a BTF standard for SVMs
based on improved PM control below
0.030 gr/dscf. However, the Agency
concluded that a BTF standard would
not be cost-effective given that the SVM
Floor level of 57 pg/dscm alone would
result in an estimated 94 percent SVM
reduction in emissions.
As discussed for PM BTF
considerations, the Agency also re-
evaluated the possible appropriateness
of using a reduced PM emissions level
based on improved PM control as a BTF
standard (with corresponding BTF
reductions in SVMs and LVMs). Even
though the SVM floor standard is higher
than at proposal, our preliminary
judgment is that significant cost-
effectiveness considerations will likely
be encountered in a final analysis of
whether to establish a BTF standard for
either SVMs or for Pb or Cd
individually.
If, however, the revised risk
assessment yet to be conducted would
show significant risk at a SVM floor
standard of either 670 pg/dscm, the
Agency will determirie'whether a BTF
standard based on control of HW SVM
feedrate to levels below those at the
floor would be appropriate. This
feedrate limitation would in turn reduce
SVM emissions. The BTF standard and
the corresponding level of feedrate
control would be dictated by
considerations of cost-effectiveness and
the need to establish more stringent
RGRA-related controls.
c. MACT floor for new sources. At
proposal, the Agency defined floor
control, based on the best performing *
source, as a fabric filter with an air-to-
cloth ratio less than 2-1 acfm/ft2 and a '
HW MTEC of 36,000 pg/dscm The,
proposed floor level for new cement
kilns was 55 pg/dscm.
Upon evaluation of the revised
database, EPA believes that the floor
control and emission level discussed
above for existing sources for SVMs
would also be appropriate for new
sources. In this event, MACT floor
control would be a well-designed,
operated and maintained PM control
device (i.e., fabric filter or ESP)
achieving the PM floor level of 0.030 gr/
dscf. The Agency's evaluation of the
revised SVM data results in a MACT
floor of 670 pg/dscm.
Finally, based on the revised
database, individual metal floor levels
for new sources are identical to those for
existing sources. Thus, individual Cd
and Pb standards are: Cd 65 pg/dscm
and Pb 550 pg/dscm.
d. BTF Considerations for new
sources. In the NPRM, the Agency
considered a SVM BTF level, but
determined that a BTF standard would
not be cost-effective.
As discussed for existing sources, the
Agency considered a more stringent PM
emissions level for improved control of
PM, SVM and LVM emissions for new
cement kilns in light of the revised •*
database. Even though the SVM floor
standard is higher than at proposal, our
preliminary judgment is that significant
cost-effectiveness considerations will *•
likely be encountered in a final analysis
of whether to establish a BTF standard
for either SVMs or for Pb or Cd
individually. • .
6. Low Volatile Metals (LVM) (arsenic,
beryllium, and chromium), a. MACT
floor for existing sources. At proposal,
EPA defined floor control as either (1)
a fabric filter with an air-to-cloth ratio
less than 2.3 acfm/ftz and a HW MTEC
of 140,000 ng/dscm, or (2) an ESP with
a specific collection area of 350 ft2/
kacfm. The proposed floor level was 130
pg/dscm, which included antimony.
.The engineering and data analysis
method used by EPA to evaluate the
revised database and identify a MACT
floor for LVMs is also related directly to
the PM floor analysis. As was
determined in the PM analysis, a floor
of 0.030-gr/dscf represents MACT for
cement kilns based on good PM control.
Considering all LVM data from sources
achieving a PM level 0.030 gr/dscf or
better, EPA's evaluation of the revised
cement kiln data would result in a LVM
floor of 63 pg/dscm (excluding sources
above a breakpoint and therefore
excluding those with substantially
poorer LVM emissions than the majority
of sources). Approximately 90 percent
of cement kiln LVM test condition data
are currently achieving this emissions
level.
Finally, as discussed for SVMs, EPA
is continuing to investigate the
appropriate structure of metals
standards (e.g., retain the volatility
groups or establish individual metals
standards). The Agency analyzed
individual As, Be, and Cr (hexavatent)
data and established individual metal
floor Jevels consistent with the
engineering evaluation and data
analysis method. Where PM
measurements are below 0.030 gr/dscf,
the result would be: As 10 pg/dscm, Be
1.1 pg/dscm, and Cr (hexavalent) 4.6
pg/dscm.
The Agency is concerned that some of
the potential floor standards for some
Individual metals (e.g., Be, Cr
(hexavalent)) may be present at levels
approaching practical quantitation
limits (PQLs). PQLs are the lowest level
of quantification that the Agency
believes a competent analytical
laboratory can be expected to reliably
achieve. The Agency will investigate
whether this issue may need to be
addressed in the development of any
individual metals standards that may be
considered for the final rulemaking. We
inyite comment on the issue of PQLs
and LVM BTF standards.
b. BTF considerations for existing
sources. In the NPRM, the Agency
considered a BTF standard for LVMs
based on improved PM control below
0.030 gr/dscf. However, the Agency
concluded .that a BTF LVM standard
would not be cost-effective.
As discussed for PM, a reduced PM
emissions level based on improved PM
control could be considered in
evaluating a potential BTF standard
(taking into consideration
corresponding BTF reductions in LVMs
and SVMs) for existing CKs. Because
both the PM and LVM floor levels
presented today would be similar to the
proposed floor, a BTF standard for
either LVMs or individual As, Be, and
Cr (hexavalent) standards based on
improved PM control would likely raise
-------
24230
Federal Register / Vol. 62, No. 85 / Friday, May 2, J.997 / Proposed Rules
significant cost-effectiveness concerns
and may not ultimately be appropriate.
c, MACT floor for new sources. At
proposal, the Agency defined floor
control, based on the best performing
source, as a fabric filter with an air-to-
cloth ratio less than 2.3 acfm/ft2 and a
HW MTEC of 25.000 ug/dscm.'The
proposed LVM floor level for new CKs
was 44 ug/dscm.
Based upon our re-evaluation of the
database, the floor control and emission
level discussed above for existing
sources for LVMs would also appear to
be appropriate for new sources. MACT
floor control Is a well-designed and
properly operated PM control device
(I.e., fabric filter, ESP) achieving the PM
floor level of 0.030 gr/dscf. The
Agency's evaluation of the LVM data
results In a MACT floor of 63 ug/dscm.
Finally, Individual metal floor levels
for new sources are Identical to those for
existing sources. Thus, the standards
would be: As 10 ug/dscm, Be 1.1 ug/
dscm, and Cr (hexavalent) 4.6 ug/dscm.
d. BTF considerations for new
sources. In the NPRM, the Agency
considered a LVM BTF level, but
determined that a BTF standard would
not be cost-effective.
As discussed for existing sources, the
Agency considered a more stringent PM
emissions level for Improved control of
PM. SVM and LVM emissions for new
CKs. Because both the alternative PM
and LVM floor levels presented today
are lower than the proposed floors, a
BTF standard for either LVMs or
individual As, Be, or Cr (hexavalent)
standards based on Improved PM
control may be inappropriate in light of
the cost-effectiveness concerns Inherent
In this scenario.
7. Hydrochloric Add and Chlorine
' (HO/Cfc). a. MACT floor for existing
sources. At proposal, the Agency
Identified floor control for total chlorine
(i.e., HC1 + C1J as feedrate control of
chlorine In the hazardous waste at an
MTEC not to exceed 1.6 g/dscm, and
proposed a floor standard of 630 ppmv.
When we evaluated the revised database
prior to today's notice, we used a data
analysis method similar to that used at
proposal. The floor control would be
defined the same way as proposed, but
the floor standard would be 120 ppmv.
This standard should be readily
achievable given that 93 percent of the
test conditions in the revised database
are meeting that level.
We used the following data analysis
steps for both the proposed standard
and today's alternative standard: (1)
Rank emissions from lowest to highest;
(?) define as floor control the highest
hazardous waste chlorine MTEC for the
6 percent of sources35 with the lowest
emissions; and (3) define as the floor
standard the highest test condition
average emissions of any test condition
operated at or below the floor MTEC
(i.e., the expanded universe). We then
refined the data analysis method in two
respects.based on an engineering
evaluation of the revised database: (1)
We did not add a computed emissions
variability factor36; and (2) several test
conditions were deleted from the
expanded universe where an
engineering evaluation revealed that ^
SREs were significantly worse than the
majority of other SREs.
In the case of total chlorine emissions
for CKs, it appears not to be appropriate
to use a breakpoint analysis to screen
from the expanded universe sources that
are not achieving an appropriate
removal efficiency. This is because total
chlorine is removed incidentally by
reactions with the alkaline raw
materials (e.g., limestone). Thus, it is
difficult to reason that poor SRE is r/
caused by poor design, operation, br :'
maintenance of the control system.
Nonetheless, we believe it is still
appropriate to screen out clearly
anomalous SREs because they are likely
indicative of an incorrect MTEC value
or emission measurement. An incorrect
value for either could affect the floor
standard.3?
b. BTF considerations for existing
sources. At proposal, the Agency
defined BTF control as wet scrubbing
with a 99 percent removal efficiency,
but determined that a BTF standard
would not be cost-effective. Given that
the alternative floor level presented
today would be substantially lower than
the proposed floor, a BTF standard
would be less cost-effective. Thus, we
believe that our final analysis is likely
to conclude that a BTF standard would
not be warranted.
c. MACT floor for new sources. At *f.
proposal, the Agency defined floor
control for new sources as hazardous
waste feedrate control for chlorine at an
MTEC of 1.6 g/dscm or less. The
proposed floor standard was 630 ppmv,
the same as the floor standard for
existing sources.
35 Or where we had data from fewer than 30
sources, the three sources with the lowest emissions
(Le.. 3 represents the median of the five best
performing sources).
asSee previous discussion in the text. As we
discussed at proposal (61 FR at 17396), the
computed variability factor for this standard
resulted in a standard that did notcomport with
engineering information on the APCDs at issue,
engineering experience on facility performance
within this source category, or the emissions
database.
37The floor standard without screening the
anomalous SREs would have been 160 ppmv.
Given that the alternative data
analysis method discussed above for •
existing sources did not change the
expanded universe, except to screen out
test conditions with anomalous SREs,
MACT floor control and the floor
emission level would be the same as for
existing sources: hazardous waste
feedrate control for chlorine at an MTEC
of 1.6 g/dscm or less, resulting in a floor
standard of 120 ppmv (i.e., after
screening out test conditions with
anomalous SREs).
d. BTF considerations for new
sources. The Agency proposed a BTF
standard for new sources of 67 ppmv
based on wet scrubbing. Given that
under the revised data analysis method
discussed today the floor standard
would be much lower than proposed,
the Agency believes that the economic
impact analysis being conducted in
support of the final rule is likely to raise
significant concerns about cost-
effectiveness. In that event, the Agency
would promulgate the 120 ppmv floor
•standard for new sources.
8. Carbon Monoxide (CO). The
Agency proposed the same MACT floor
standards for CO for existing and new
CKs, and determined that BTF controls
would not be cost-effective. Floor
control was defined for kilns with by-
pass ducts as operation under good
combustion practices and the standard
was 100 ppmv, HRA, measured in the
by-pass duct For kilns without a by-
pass duct (i.e., long wet and dry kilns),
no CO standard was proposed given that
CO levels in the main stack would not
be an indicator of combustion
efficiency. This is because CO can be-
generated by process chemistry (i.e.,
dissociation of CO2 to form CO) and
evolution from trace organics in the raw
material feedstocks, as well as from
combustion of fuels. .
The Agency continues to believe that
the proposed CO standard for kilns
equipped with a by-pass duct would be
appropriate. However, under one option
being considered for limiting CO (and
HC) emissions, kilns without a by-pass
duct would also be required to comply -
with a CO limit based on the level
achieved during the performance test
demonstrating compliance with the HC
limit. See discussion in Part Two,
Section II.C.
Finally, the Agency continues to
believe that a BTF standard for CO
based on better combustion practices is
likely to raise significant cost-
effectiveness considerations.
9. Hydrocarbons (HC). The Agency
proposed the same MACT floor .
standards for HC for existing and new
CKs, and determined that BTF controls
would not be cost-effective. Floor
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2. 1997 / Proposed Rules
24231
control was defined for kilns with by-
pass ducts as operation under good
combustion practices and the standard
was 6.7 ppmv, based on an hourly
rolling average (HRA and measured in
. the by-pass duct. For kilns without a by-
pass duct (i.e., long wet and dry kilns),
floor control was defined as good
combustion practices and use of raw
materials with relatively low organic
content, and the standard was 20 ppmv,
HRA., measured in the main stack.
In evaluating the revised database for
today's notice, the 20 ppmv standard
still appears to be appropriate for the
main stack of long kilns 38. When
considering by-pass kilns, however, the
revised database still lacks HC
emissions data for the only two CKs
currently burning hazardous waste in
units equipped with by-pass ducts.
These two sources are complying with
the BIF rules by documenting that CO
levels are below 100 ppmv, HRA.39
Under one attractive option for
compliance with the CO and HC
standards (i.e., sources would have the
option of complying with either the CO
or HC standard; see discussion in Part
Two, Section ILC), we would expect
that these two sources would continue
to comply with the CO limit. Thus, it
may not be necessary to establish a HC
limit for them. However, given that it
may be prudent to establish a HC limit
for. these by-pass kilns, we would
transfer the good combustion practices-
based HC standard for incinerators—10
ppmv, HRA—to these kilns. This is
appropriate because: (1) Good
combustion practices is floor control for
CO and HC for these kilns as well as for
incinerators; and (2) given that the good
combustion practices-based CO **
standard is the same for incinerators
and by-pass kilns, the good combustion
practices-based HC standard should also
be the same.
As discussed at proposal, the Agency
continues to be concerned about cost-
effectiveness considerations related to
BTF controls for HC based on operating
under better combustion practices.
G. Re-Evaluation of Proposed MACT
Standards for Lightweight Aggregate
Kilns
We discuss in this section the basis
for the revised standards for LWAKs
that could result from applying various
engineering evaluation and data
analysis methods to the revised
emissions database40. A comparison of
the proposed and potentially revised
standards for existing and new sources
is presented in the table below:
TABLE ll.G:—REVISED STANDARDS FOR EXISTING AND NEW LWAKs1
HAP or. HAP surrogate
D/F (ng TEQ/dscm) '.
PM (gr/dscf)
HCI/CI2 (ppmv)
SVM (ug/dscm)
LVM (ug/dscm) :
Existing sources
Proposed
standard
0.20
72
0.030
450
100
14
12
340
Revised
standard
0.20
47
0.022
130
100
10
76
37
New sources
Proposed
standard
0.20
72
0.030
62
100
14
5.2
55
. Revised
standard
0.20
47
0.022
43
100
10 .
76
37
1 All emission levels are corrected to 7% Oz.
1. Dioxins andFurans (D/F). a. MACT
floor for existing sources. At proposal,
the Agency had D/F emissions for only
one LWAK and therefore pooled that
LWAK data point with D/F data for CKs
to identify MACT standards.
Consequently, floor control and the
floor emission level for LWAKs were the
same as for CKs. The proposed floor
control was "temperature control at the
inlet to the fabric filter41 at 418 °F". and
the proposed floor emission level was
"0.20 ng TEQ/dscm, or.temperature at
the inlet to the fabric filter not to exceed
418 °F". The Agency reasoned that
pooling D/F data for LWAKs and CKs
could be appropriate because both types
38 The Agency did not propose a HC standard for
the main stack of a preheater or preheater/
precalciner kiln. See FR at 17397-8. The Agency is
currently developing MACT standards for non-
waste burning cement kilns, however. Any
standards that the Agency may propose that are
applicable to the main stack of a preheater or
preheater/precalciner. non-waste burning kiln may
also be appropriate for the main stack of such
hazardous waste burning kilns.
39 The two kilns operating with by-pass ducts are
Medusa's facility in Demopolis, AL, and Lone Star's
facility in Cape Girardeau, MO. We note that
of devices are designed and operated
similarly with respect to factors that can
affect surface-catalyzed D/F formation,!1'"
Both LWAKs and CKs have high PM
inlet loadings comprised primarily of
entrained raw material and both are
equipped with fabric filters that operate
within the same temperature range.
Commenters on the proposed rule,
however, argued that pooling LWAK
and CK D/F data was inappropriate for
purposes of establishing MACT
standards for LWAKs. Since proposal,
the Agency has obtained D/F emissions
data from two additional LWAK
facilities. These data are included in the
revised emissions database and are used
Holnam has a long wet kiln in Clarksville, MO that
has been retrofitted with a mid-kiln sampling port
for purposes of monitoring CO in compliance with
the BIF rule. That monitoring approach would be
acceptable under the MACT rule as well.
40 Additional details of the engineering and data
analysis evaluations performed on the revised
emissions database can be found in the Agency's'4'
background document; USEPA, "Draft Technical
Support Document for HWC MACT Standards
(NODA), Volume I: MACT Evaluations Based on
Revised Database", April 1997.
to identify the alternative standards
presented here.
Based upon evaluation of the revised
LWAK D/F database, our engineering
evaluation of the data and other
information on LWAK performance
suggests the floor control can be
specified as "temperature control at the
inlet to the fabric filter at 400 °F". This
would result in a floor emission level of
"0.20 ng TEQ/dscm, or 4.1 ng TEQ/
dscm and temperature at the inlet to the
fabric filter not to exceed 400 "F1.4?
Given that the entire revised database
also comprises the expanded universe
(all sources using floor control) the
highest single run for the test condition
JI AH LWAKs currently burning hazardous waste
are equipped with fabric filters.
42 The standard would be expressed in the form
of a TEQ level combined with a maximum
temperature at the PM control device. This form of
the standard is consistent with the revised data and
would result in somewhat lower emissions (i.e.,
because without the TEQ limit, some sources could
exceed that TEQ level at the specified temperature).
Thus, expressing the standard in this form better
achieves the statutory mandate to establish
standards that provide the maximum degree of
reduction that is achievable in practice.
-------
24232
Federal Register / Vol. 62, No. 85 / Friday, May 2, .1997 / Proposed Rules
with the highest run average would be
a reasonable floor level from an
engineering perspective. (Note that if
this were a large data set, the floor level
could be Identified simply as the
highest test condition average.) This
floor level Is more than 40 percent
higher than the highest test condition
average (because of substantial
variability among the runs for that test
condition), and thus appears to be a
level that LWAKs should be able to
meet routinely using floor control.
As discussed for CKs, temperature
control to 400 °F or less Is appropriate
for floor control because, from an
engineering perspective, it is within the
range of reasonable values that could
have been selected considering that: (1)
The optimum temperature window for
surface-catalyzed D/F formation is 450-
750 °F; and (2) below 350 °F, kiln gas
can fall below the dew point which can
Increase corrosion In fabric filters and
reduce performance of the control
device. In addition, more than three
LWAKs in the revised database were
operated at temperatures of 400 °F or
less (even though we do not have D/F
emissions data for them). Thus, this
temperature level appears to be readily
achievable.
Although only two of the three
LWAKs for which we have D/F
emissions data operated the fabric filter
at 400 °F or lower (the third operated at
417 °F), we have fabric filter operating
data for other LWAKs when performing
emissions testing for other HAPs that
document fabric filter operations at 400
•F or lower. The LWAK whose fabric
filter was operated at 417 °F had lower
D/F emissions than a kiln whose fabric
filter was operated at 400 °F. Thus, even
though our engineering evaluation did
not explicitly include the LWAK whose
fabric filter operated at 417 °F, defining
MACT floor control as "temperature
control at the Inlet to the fabric filter at
400 "F" did not result In a lower MACT
floor emission level (i.e., lower than 4.1
ng TEQ/dson). Rather, doing so ensures
that LWAKs'wlH be operating at floor
levels consistent with sound operational
practices for controlling D/F.
b. BTF considerations for existing
sources. The Agency proposed a BTF
standard of 0.20 ng TEQ/dscm based on
ACI operated at a temperature of £400
•F.
Upon evaluation of the revised LWAK
D/F database, LWAKs appear to be able
to achieve a 0.20 ng TEQ/dscm standard
simply by rapidly quenching
combustion gases at the exit of the kiln
to £400 °F, and insulating the duct-work
leading to the fabric filter to maintain
gas temperatures and avoid dew point
problems. Although the data are not'
conclusive, and-further testing is
warranted to confirm this approach, our
engineering evaluation of all available
information indicates that this approach
should be feasible.43 If this approach
proves to be less effective than ,
anticipated, then ACI can be used to Jr«
achieve the BTF standard.
We continue to believe that this BTF
standard is appropriate given the s
concerns the Agency has expressed
about the risks posed by D/F emissions.
See discussion regarding a D/F BTF
standard for CKs at 61 FR 17392.
Further, a BTF standard of 0.20 ng TEQ/
dscm would preclude the need to
provide further controls under RCRA
authority.
c. MACT floor for new sources. At
proposal, the BTF considerations for
new LWAKs were the same as for new
CKs, and the proposed standards were
the same.
Upon evaluation of the revised LWAK
D/F database, the floor control and
emission level discussed above for
existing sources would also appear to be
appropriate for new sources (i.e.,
"temperature control at the inlet to the
fabric filter at 400 °F" corresponding to
an emission level of "0.20 ng TEQ/
dscm, or 4.1 ng TEQ/dscm and
temperature at the inlet to the fabric
filter not to exceed'400 °F". Our
engineering evaluation indicates that *f
the best controlled source is one that is
controlling temperature control at the
inlet to the fabric filter at 400 °F.
d. BTF considerations for new
sources. The Agency proposed ACI as
BTF control and a BTF standard of 0.20
ng TEQ/dscm. We continue to believe
that this BTF standard is appropriate for
new sources for the same reasons
discussed above in the context of
existing sources. Note that BTF control,
as for existing sources, would be
defined as rapid quench of kiln gas to
<400 °F combined with duct insulation,
as required, or ACI operated at £400 °F.
2. Mercury (Hg) a. MACT Floor for
existing sources. At proposal, the
Agency identified floor control as
hazardous waste feedrate control not to
exceed an.MTEC of 17 ng/dscm. EPA
proposed a floor standard of 72 ug/
dscm.
All LWAKs employ fabric filters and-,*
one source uses a fabric filter and
venturi scrubber to control mercury.
However, since Hg is generally in the
vapor form in and downstream of the
combustion chamber, including the air
pollution control device, fabric filters
«See USEPA. "Draft Technical Support
Document for HWC MACT Standards (NODA),
Volume I: MACT Evaluations Based on Revised
Database", April 1997.
alone do not achieve good mercury
control. Mercury emissions from
LWAKs are currently controlled under
the BIF rule, which establishes limits on
the maximum feedrate of Hg in total
feedstreams (e.g., hazardous waste, raw
materials). Thus, MACT is based on
hazardous waste feed control.
Review of the updated Hg data in the
revised database indicate that LWAKs
did not conduct Hg spiking of the
hazardous wastes with the exception of
one facility, and thus the Hg content in
the wastes during testing is likely
representative of typical operations. The
data from this testing also show that raw
materials can represent a significant
source Hg input to the kiln system:
Since the best performing sources,
measured by Hg emissions, do not
employ a dedicated device capable of
Hg control, the Agency believes that the
Hg data are essentially "normal" even
though generated during worst case
compliance testing conditions for other
parameters.
To evaluate these revised data for the
purpose of determining a MACT floor,
the Agency used the following data
analysis steps: (1) Rani; Hg emissions
from lowest to highest; (2) conduct a
breakpoint analysis on the ranked Hg
emissions data, and (3) establish the
, floor standard equal to the test
condition average of the breakpoint
source. The breakpoint analysis reflects
an engineering evaluation of the data
and ensures that the one source that
spiked elevated quantities of Hg did not
drive the floor level upward to levels
higher than the preponderance of this
"normal" data indicates is routinely
achievable. The Agency's analysis
results in a MACT floor level of 47 ug/
dscm. The revised database indicates
that approximately 75 percent of
LWAKs are achieving this floor level.
b. BTF considerations for existing
sources. The Agency originally
considered a BTF standard based on
flue gas temperature reduction to 400 °F
or less followed by ACI, but determined
that a BTF level would not be
warranted.
EPA continues to believe that flue gas
temperature reduction to 400 °F
followed by ACI is the appropriate BTF
control option for improved Hg control
at LWAKs. As discussed above for •
existing CKs, we have assumed an ACI
effectiveness of 60 percent in
identifying BTF levels for LWAKs for
the purposes of today's analysis. Thus,
the BTF standard is 15 ug/dscm which
is based on a ACI efficiency of 60
percent applied to the floor level of 33
ug/dscm. Going to a BTF standard of 15
jig/dscm for mercury is consistent with
the range examined in the proposal.
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, *997 / Proposed Rules
24233
However, at proposal, significant cost-
effectiveness issues were raised (and
commented extensively on). It is likely
that those same issues would arise here
with respect to a BTF standard of 15 ng/
dscm.
c. MACT floor for new sources. At
proposal, the Agency identified floor
control as hazardous waste feedrate
control not to exceed an MTEC of 17 \ig/
dscm—the same as existing sources.
Thus, EPA proposed an identical floor
standard of 72 ng/dscm.
For the same reasons discussed for
existing LWAKs, the Agency believes
that the most appropriate engineering
evaluation and data analysis method to
identify the floor level is identical to the
analysis done for existing sources. Thus,
the MACT Floor standard would be 47
Jig/dscm for new LWAKs.
d. BTF considerations for new
sources. The Agency considered a BTF
standard for new sources based ori ACT,
but determined that it would not be
cost-effective to adopt the BTF standard.
The Agency continues to consider the
use of ACI as the BTF technology.- In
evaluating the revised database, EPA
has identified a level of 15 (ig/dscm as
the BTF standard for new sources based
on ACI and flue gas temperature
reduction to 400 °F or less. This is based
on a source achieving the MACT new
floor level of 33 ug/dscm and then
applying ACI with a 60 percent removal
efficiency. Again, in light of the reasons
identified for existing sources, the
Agency has concerns as to whether a
BTF level based on ACI will ultimately
be warranted for new LWAK sources.
3. Particulate Matter (PM). a. MACT
Floor for Existing Sources. At proposal,
EPA defined floor control as a fabric
filter with an air-to-cloth ratio of 2.8
acfm/ft2. The MACT floor was 0.049 gr/
dscf.
In evaluating the revised database, we
examined a refined engineering
evaluation and data analysis method to
identify a MACT floor. This evaluation
was a four-step process: (1) Rank all PM
emissions data and identify the MACT
floor controls used by the best.
performing 6 percent of sources. (2)
Develop the expanded universe to
include all sources employing MACT
control, without further characterizing
MACT control (e.g., air-to-cloth ratio of
the fabric filter) as done in the proposal
because we do not have sufficient data
on the detailed design, operating, and
maintenance characteristics related to
test conditions in the revised database.
Since all LWAKs use fabric filters for
PM control, all test condition data are
included in the expanded universe. (3)
For each PM test condition, evaluate the
corresponding SVM SRE and screen out
sources that have relatively poor SREs
(i.e., outliers above a breakpoint in the
data array), which is an indicator of
poor design, operation, and
maintenance characteristics of the
MACT controls at the source. (4)
Identify the MACT floor equal to the
highest test condition average of all test
conditions in the PM expanded
universe.
The Agency's evaluation of the LWAK
PM data results in a MACT floor of
0.022 gr/dscf. All LWAK test condition
data are achieving 0.022 gr/dscf.
LWAKs typically operate at higher
stack oxygen concentrations comparer
to other combustion systems due to the
LWAK manufacturing process (e.g.,
excess air is forced into the kiln to aid
in the expansion of the raw material
into lightweight aggregate). Typical
stack oxygen concentrations range from
12 to 16 percent, while CKs, for
example, typically range from 3 to 8
percent. Since the standards are
expressed at 7 percent oxygen, the floor
standard of 0.022 gr/dscf would be
equivalent to 0.014 gr/dscf at 12 percent
oxygen and 0.008 gr/dscf at 16 percent
oxygen under the conditions that
LWAKs typically operate.
In the NPRM, the Agency proposed
that sources maintain co'ntinuous
compliance with the PM standard
through the use of a PM CEMS. A
decision whether to require LWAKs to
install a PM CEMS will be made at the
completion of an on-going
demonstration testing program to ^
determine if at least one PM CEMS can
meet the proposed performance
specifications. Since the floor standard
discussed above was based on manual
test method data, the Agency will re-
evaluate at the completion of the CEMS
testing program whether these PM floor
standards would be appropriate in the
event that the final rulemaking requires
continuous compliance with a PM
CEMS. The Agency will notice the
results and conclusions of the
demonstration test program in the
docket for the HWC rule.
b. BTF considerations for existing-
sources. In the NPRM, the Agency
proposed a BTF level of 0.030 gr/dscf
and solicited comment on an alternative
BTF level of 0.015 gr/dscf based on
improved PM control.
Based on the revised database, we can
evaluate a reduced PM emissions level
lower than 0.022 gr/dscf as the BTF
standard (in conjunction with BTF
reductions in SVMs and LVMs). This
would require an improved PM
collection technology such as the use of
more expensive fabric filter bag *
material. Given that the alternative floor
level analysis presented today would be
substantially lower than the proposed
floor and BTF levels, significant cost-
effectiveness considerations come into
play and suggest that BTF levels may
not ultimately prove to be warranted.
c. MACT floor for new sources. At
proposal, EPA defined floor control for
new sources as a fabric filter with an air-
to-cloth ratio of 1.5 acfm/ft2. The MACT
floor was 0.054 gr/dscf.
Based upon evaluation of the revised
database, the floor control and emission
level discussed above for existing
sources would also appear to be
appropriate for new sources. Therefore,
MACT floor control is a well-designed
and properly operated fabric filter, and
the MACT floor for new LWAKs is 0.022
gr/dscf.
d. BTF considerations for new
sources. In the NPRM, EPA proposed a
BTF standard of 0.030 gr/dscf based on
improved PM control, which was
consistent with existing sources.
Today, as discussed above for existing
source BTF considerations and based
upon examining the revised database in
light of the findings at proposal, a BTF
standard for new sources beyond 0.022
gr/dscf (and corresponding BTF
reductions for SVMs and LVMs) would
not appear to be cost-effective.
4. Semivolatile Metals (SVM)
(cadmium and lead), a. MACT floor for
existing sources. At proposal, EPA
defined floor control as either (1) a
fabric filter with an air-to-cloth ratio of
1.5 acfm/ft2 with a hazardous waste
(HW) MTEC less than 270,000 jig/dscm,
or (2) a combination of a fabric filter and
venturi scrubber with an air-to-cloth
ratio of 4.2 acfm/ft2 and a HW MTEC
less than 54,000 jig/dscm. The proposed
floor level was 12 ug/dscm.
LWAKs use a combination of good
PM control and limiting hazardous
waste feedrates to control SVM
emissions. SVMs are controlled most
efficiently by technologies which are
effective at capturing fine PM, such as
fabric filters which are employed by all
LWAKs. EPA's revised database shows
that SVM emissions vary substantially
from 3 to over 1600 jig/dscm with 60
percent below 80 ug/dscm and the
remaining 40 percent above 400 jig/
dscm.
The refined data analysis method
used by EPA to evaluate and identify a
MACT floor would be based directly on
the results from the PM floor analyses
discussed above. As mentioned there,
0.022 gr/dscf would appear to represent
the MACT floor for LWAKs based on
good PM control. Since SVMs are
controlled, in part, by a well-designed
and operated PM control devices, it
follows that sources achieving this PM
-------
24234
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
performance level should also be
controlling SVMs emissions.
Therefore, In Its refined SVM analyses
of the revised database, the Agency
would first consider all SVM data when
corresponding PM measurements are
below 0.022 gr/dscf. To Identify the
SVM floor from these data, we identify
either at the highest SVM test condition
average or the level that excludes
sources achieving substantially poorer
SVM control than the majority of
sources. It is most likely appropriate to
use the latter approach—excluding
sources with significantly poorer SVM
performance—because their higher SVM
emissions may be the result of
exceedingly high SVM feedrates or some
other factor which Is not able to be
discerned from the data available to the
Agency. An SVM emissions breakpoint
analysis Is the approach for excluding
these poorer performing test conditions.
Applying this evaluation technique to
the revised LWAK SVM database results
In a MACT floor of 76 ug/dscm.
Approximately 62 percent of LWAK
SVM test condition data are currently
achieving this emissions level.
Finally, as discussed in an earlier
section, a preliminary analysis Indicates
that MACT standards may not be
warranted for one HAP metal, antimony.
Since the number of metals being
considered for MACT standards may
change, we are investigating the
appropriate structure of metals
standards (e.g., retain the volatility
groups or establish individual metals
standards). Using the refined method
discussed above for SVM, we analyzed
the revised database with respect to Cd
and Pb data. The floor analysis
corresponding to PM measurements
below 0.022 gr/dscf would result In the
following floor levels: Cd 53 ug/dscm,
and Pb 67 ug/dscm.
b. BTF considerations for existing
sources. In the NPRM, the Agency
considered a BTF standard for SVMs
based on improved PM control.
However, the Agency concluded that a
BTF standard would not be cost-
effective given drat the SVM floor level
of 12 ug/dscm alone would result in an
estimated 97 percent SVM reduction in
emissions.
As discussed for PM BTF
considerations, the Agency also re-
evaluated the possible appropriateness
of using a reduced PM emissions level
based on Improved PM control as a BTF
standard (with corresponding BTF
reductions in SVMs and LVMs). Even
though the alternative SVM floor
standard is higher than at proposal, our
preliminary judgement is that
significant cost-effectiveness
considerations will be nonetheless
encountered in a final analysis of
whether to establish a BTF standard for
SVMs or for Pb or Cd individually.
If, however, the revised risk
assessment yet to be conducted would
show significant risk at a SVM floor
standard of 76 ug/dscm, which would
be the floor level resulting from
application of die data analysis method
discussed above, die Agency will
determine whether a BTF standard
based on control of SVM feedrate to
levels below those at the floor would be
appropriate. This feedrate limitation
would in turn reduce SVM emissions.
The BTF standard and the
corresponding level of feedrate control
would be dictated by considerations of
cost-effectiveness and the need to.
establish more stringent RCRA-related
controls.
c. MACT floor for new sources. At
proposal, EPA defined floor control as a
fabric filter with an air-to-clotii ratio of
1.5 acfm/ft2 widi a hazardous waste
(HW) MTEC less than 270,000 ug/dscm..
The proposed floor level was 5.2 ug/ r
dscm.
Upon evaluation of the revised
database, EPA believes diat the floor
control and emission level discussed
above for existing sources for SVMs
would also be appropriate for new
sources. In this event, MACT floor
control would be a well-designed,
operated and maintained PM control
device (e.g., fabric filter) achieving the
PM floor level of 0.022 gr/dscf. The
Agency's evaluation of die SVM data
results in a MACT floor of 76 ug/dscm.
Finally, based on die revised
database, individual metal floor levels
for new sources are identical to those for
existing sources. Thus, individual Cd
and Pb standards are 53 ug/dscm for Cd
and 67 ug/dscm for Pb.
d. BTF considerations for new
sources'. In the NPRM, the Agency
considered a SVM BTF level, but
determined diat a BTF standard would
not be cost-effective.
As discussed for existing sources, the
Agency considered a more stringent PM
emissions level for Improved control of *•
PM. SVM and LVM emissions for new
LWAKs in light of the revised database.
Even diough die SVM floor standard is
higher than at proposal, as discussed
above, cost-effectiveness issues are
again raised and suggest that a BTF
standard for eiflier SVMs or for Pb or Cd
individually based on improved PM
control may likewise ultimately prove to
be inappropriate.
5. Low Volatile Metals (LVM) (arsenic,
beryllium, and chromium) a. MACT
Floor for Existing Sources. At proposal,
EPA defined floor control as a fabric <*
filter widi an air-to-cloth ratio of 1.8
acfm/ft2 widi a HW MTEC less dian
46,000 ug/dscm.
The proposed floor level was 340 ug/
dscm, which included antimony.
LWAKs use a combination of good
PM control and limiting hazardous
waste feedrates to control LVM
emissions. LVMs are less likely to
vaporize at combustion temperatures
and dierefore partition primarily to die
residue or adsorb onto particles in die
combustion gas. EPA's database shows
diat LVM emissions vary from around
20 to 285 ug/dscm.
The engineering evaluation data
analysis method used by EPA to
evaluate die revised database and
identify a MACT floor for LVMs is also
related directly to the PM floor analysis.
As was determined in die PM analysis, '
a floor of 0.022 gr/dscf represents MACT
for LWAKs based on good PM control.
Considering all LVM data from sources
achieving a PM level 0.022 gr/dscf or
better, EPA's evaluation of die revised
LWAK data results in a LVM floor of 37
ug/dscm (excluding sources above a
breakpoint and therefore achieving
substantially poorer LVM emissions
dian the majority of sources).
Approximately 71 percent of LWAK
LVM test condition data are currently
achieving diis emissions level.
Finally,'as discussed for SVMs, EPA
is continuing to investigate the
appropriate structure of metals
standards (e.g., retain the volatility
groups or establish individual metals
standards). The Agency analyzed
individual As; Be, and Cr (hexavalent)
data and established individual metal
floor levels'consistent with the
engineering evaluation and data
analysis mediod. Where PM
measurements are below 0.022 gr/dscf,
the result would be: As 22 ug/dscm, Be
3 ug/dscm, and Cr (hexavalent) 6.2 ug/
dscra.
The Agency is concerned that some of
the potential floor standards for some
individual metals (e.g., Be, Cr .
(hexavalent)) may be present at levels
approaching practical quantitation
limits (PQLs). PQLs are die lowest level
of quantification that the Agency
believes a competent analytical
laboratory can be expected to reliably
achieve. The Agency will investigate
whedier tiiis issue may need to be
addressed in the development of any
individual metals standards that may be
considered for die final rulemaking. We
invite comment on the issue of PQLs
and LVM BTF standards.
b. BTF considerations for existing
sources. In the NPRM, die Agency
considered a BTF standard for LVMs
based on improved PM control.
However, die Agency concluded that a
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
24235
BTF standard would not be cost-
effective.
As discussed for PM BTF
considerations, the Agency also re-
evaluated the possible appropriateness
of using a reduced PM emissions level
based on improved PM control as a BTF
standard (with corresponding BTF
reductions in SVMs and LVMs).
Considering that the alternative LVM
floor standard would be lower than at
proposal, our preliminary judgment is
that significant cost-effectiveness
considerations will likely be
encountered in a final analysis of
whether to establish a BTF standard for
either LVM or for As, Be, or Cr
(hexavalent) individually.
c. MACT floor for new sources. At
proposal, EPA defined floor control as a
fabric filter with an air-to-cloth ratio of
1.3 acfm/ft2 with a hazardous waste
(HW) MTEC less than 37,000 ng/dscm.
The proposed floor level was 55 |ig/
dscm.
. Based upon our re-evaluation of the
database, the floor control and emission
level discussed above for existing
sources for LVMs would also appear to
be appropriate for new sources. MACT
floor control is a well-designed and
properly operated PM control device '
(i.e., fabric filter) achieving the PM floor
level of 0.022 gr/dscf. The Agency's
evaluation of the LVM data would result
in a MACT floor of 37 (ig/dscm.
Finally, individual metal floor levels
for new sources are identical to those for
existing sources. Thus, the standards
would be: As 22 ng/dscm,.Be 3 jig/dscm,
and Cr (hexavalent) 6.2 ng/dscm.
d. BTF considerations for new
sources. In the NPRM, the Agency
considered a LVM BTF level, but
determined that a BTF standard would
not be cost-effective.
As discussed for existing sources, the -
Agency considered a more stringent PM
emissions level for improved control of
PM, SVM and LVM emissions for new
LWAKs. Because the alternative PM and
LVM floor'levels presented today are
lower and approximately equivalent,
respectively, than the proposed floors, a
BTF standard for either LVMs or
individual As, Be, or Cr (hexavalent)
standards based on improved PM
control may be inappropriate in light of
the cost-effectiveness concerns inherent
in this scenario.
6. Hydrochloric Acid and Chlorine
(HCl/Clz) a. MACT floor for existing
sources. At proposal, the-Agency
identified floor control for total chlorine
as either: (1) Hazardous waste feedrate
control of chlorine to a MTEC of 1.5 g/
dscm or less; or (2) venturi scrubber
with hazardous waste MTEC of 14 g/
dscm or less. The proposed floor
emission level was 2100 ppmv.
Upon evaluation of the revised
database, the data analysis method used
at proposal appears still to be
appropriate and, consequently, floor
control would be defined virtually the
same as at proposal. However, EPA no
longer thinks it appropriate to add a
computed emissions variability factor to
the standard-setting test condition for
large data sets44. Thus, the floor
emission level would be 1300 ppmv
rather than 2100 ppmv.
b. BTF considerations for existing
sources. At proposal, the Agency
defined BTF control as wet or dry lime
scrubbing with a control efficiency of 90
percent and proposed a BTF standard of
450 ppmv.
The Agency continues to believe that
wet or dry lime scrubbing can achieve
at least 90 percent removal of HC1/C12.
Therefore, the revised BTF standard
would be 130 ppmv assuming that the
requisite cost-effectiveness information
continues to suggest that a BTF standard
is warranted. The two LWAKs that are
equipped with wet scrubbers achieved
emission levels below 45 ppmv.
c. MACT floor for new sources. At .
proposal, the'Agency defined MACT
floor control for new sources as a ^
venturi scrubber with a hazardous waste
MTEC of 14 g/dscm or less, and
identified a floor level of 62 ppmv.
As for existing sources, the data
analysis method used at proposal for
new sources is appropriate and,
consequently, floor control for new
sources would be defined the same as at
proposal. Excluding a computed
emissions variability, the floor emission
level would be 43 ppmv rather than 62
ppmv.
d. BTF considerations for new
sources. The Agency did not propose a
BTF standard for new sources because
the floor standard was based on best
available control technology: wet
scrubbing. We have no new information
in the revised database that would
indicate that this conclusion at proposal
should be revisited.
7. Carbon Monoxide (CO). The
Agency proposed a MACT standard for
CO of 100 ppmv based on a hourly
rolling average (HRA). We continue to
believe that this standard is appropriate
for the reasons expressed in the
preamble to the proposal.
8. Hydrocarbons (HC). The Agency
proposed a HC level of 14 ppmv based
on floor control using good combustion
practices. Although we continue to
believe that floor control is good
combustion practices, our engineering
44 See discussion in Part Two, Section U.D.
evaluation of the revised database
suggests that a floor standard of 10
ppmv, HRA, may be more appropriate.
The single LWAK facility in the revised
emissions database that could not
achieve a HC standard of 10 ppmv
(perhaps because of trace organics in the
raw material) has stopped burning
hazardous waste. Data from that facility
have been excluded in. the revised
analysis. Although the remaining
LWAKs appear to be able to meet a HC
standard on the order of 6 ppmv, it may
be more appropriate to establish the
standard at 10 ppmv. This is because we
are not aware of an engineering reason
that LWAKs using good combustion
practices should be able to achieve •
lower HC emissions than incinerators.
Given that the incinerator HC standard
would be 10 ppmv, that standard also
appears to be appropriate for LWAKs.
Fart Three: Implementation
/. Compliance Date Considerations
The Agency proposed that all sources
subject to the final rule be in
compliance with the final standards
three years following the effective date
of the rule (61 FR 17416). The proposed
compliance period is consistent with
the CAA, which defines the maximum
compliance period for sources regulated
under the statute as three years, with the
possibility of a one-year extension for
those sources that adequately
demonstrate a need for additional time
for the installation of emission controls.
The Agency proposed the maximum
compliance period allowed by the Act
because this rule will likely require the
majority of units, currently operating
under RCRA regulations, to undergo
substantial modifications to come into
compliance with the potentially more
stringent final MACT standards.
The general provisions of 40 CFRPart
63 do not require a demonstration of
compliance until 240 days following the
compliance date. This 240 day period
between the compliance date and the
demonstration of compliance is clearly
not appropriate for HWCs because these
devices are presently regulated under
RCRA via enforceable operating limits,
and in this interim period the -
enforceable operating limits would be
undefined (61 FR 17415).
Therefore, to provide consistency
with the currently-applicable RCRA
regulatory compliance scheme, the
Agency departed from the general
requirements applicable to MACT
sources and proposed a revised
definition of compliance date. The
proposed definition of compliance date
would require sources to complete
installation of controls and to
-------
24236
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
successfully complete performance
testing and certify compliance within
the three-year compliance period, not by
a date 240 days after the three-year
compliance period. Id. In addition to the
revised definition of compliance date,
the Agency also proposed a number of
extra consequences for H WC sources
that are not in compliance by die
compliance date: (1) Immediate
termination of waste-burning activities;
(2) loss of RCRA permit or interim
status; (3) a requirement to obtain a new
RCRA. permit; an^i (4) compliance with
MACT standards for new sources.
In response to the proposal, the
Agency received comments suggesting
the three-year compliance period would
be Impossible to meet due to a number
of competing factors, and that more time
would be necessary to comply with the
rule. These factors Included permit
modification, installation of controls,
and documentation of compliance.
Furthermore, commenters expressed
serious concerns about combining these
factors with the consequences of
missing the compliance date. Industry
commented that under this proposed
approach facilities engaged in legitimate
efforts to comply with the standards
would be forced to terminate waste-
burning activities, and be subjected to
burdensome consequences that are
unnecessary to protect the environment
or ensure the public's safety.
However, EPA has become persuaded
by commenters concerns regarding the
ability of HWC sources in particular to
comply with die proposed standards by
the compliance date. Sources will have
to modify their RCRA^permlts. Further,
some sources may choose to pursue
waste minimization strategies. For these
reasons, the Agency is considering
certain actions that may be finalized in
advance of die final HWC rule such as,
the streamlined permit modification
procedures discussed at 17455 In the
proposal; as well as, the waste
minimization option for extension of die
compliance date to allow for the
application of waste minimization
controls to meet die final standards
discussed at 17417. The streamlined
permit modification procedures would
reduce the administrative requirements
and dme necessary to begin
modification procedures required to
comply with the final standards. The
waste minimization compliance date
extension option, which provides an
additional avenue for facilities to
request an extension of die .compliance
date, would afford facilities that choose
to Institute waste minimization
measures an additional year to complete
these actions.
However, even widi die special
provisions under consideration, sources
may require die full amount of time
allowed under die CAA to comply.
Therefore, die Agency is also
considering a revised implementation
scheme dial will allow for a simplified
approach consistent widi die
implementation of general CAA-MACT
rules. This approach would provide
both additional relief to sources
complying widi the final rule, and
information regarding a source's
compliance status on die compliance
date for die Agency. The specifics of
.this new option are explained in greater
detail in die following paragraphs.
Comments are requested on diis new
approach to implementing die HWC
MACT standards.
A. Definition of Compliance Date
Today, die Agency is considering a
revision to die proposed definition of
compliance date. Under tiiis revised
approach, HWC sources would follow
die CAA-MACT schedule for
demonstration of compliance, through
MACT performance testing and
submission of test results, contained in
§ 63.7. Under tiiat section, affected
sources must conduct performance tests
witiiin 180 days following die
compliance date, and submit die results
of die tests 60 days following the
completion of die performance test.4? >A
This CAA-based approach responds to
the comments questioning our revised
definition of compliance date and
would achieve a more consistent
implementation framework. However,
because die Agency is concerned about.
die compliance status of affected
sources on die compliance date, die
Agencyalso seeks comment on
provisions to enhance die general
requirements for H WCs widi a
requirement for die submission of a
"precertification of compliance" in die
final rule. A precertification of
compliance would require facilities to
precertify dieir compliance status on die
compliance date. The details of the
precertification of compliance are
described in greater detail in the
following paragraphs.
B. Pre-Certification of Compliance
Today the EPA is seeking comment on
an option which would require sources
to submit a notification to regulatory
agencies that details the operating limits
a unit will be operated under in the
interim period following the compliance
date but before die results of die initial
comprehensive performance test are
submitted. This notification, die
precertification of compliance, would
include all of the information necessary
to determine the compliance status of an
affected source (e.g., automatic waste
feed cutoff limits, feedrate limits,
emission control device operating
limits, etc.) during die 240 day period
after the compliance date. At a
minimum, the facility would be
required to establish-operating limits on
all of die parameters identified in the
proposed monitoring requirements
found in.table V.2.1 at 17419 of the
proposed rule. This approach is
appropriate because these facilities are
already regulated under RCRA. There
should not be any ambiguity for these
facilities in terms of being between
regulatory regimes at any point in time.
The operating limits in die
precertification of compliance would be
enforceable limits.46 However, if
following the initial comprehensive
performance test, die facility's
precertification of compliance
designated operating limits are found to
have been inadequate to ensure
compliance widi die MACT standards,
die facility will not be deemed out of
compliance widi the MACT emissions
standards. EPA invites comment on this
approach, and specifically invites
comment on die necessity of
establishing operating limits on die
entire set of parameters identified in
table V.2.1.
C. Consequences of Non-compliance
As mentioned earlier, die Agency
proposed a number of serious
consequences that would befall a source
that misses die compliance date (61 FR
17416). The Agency proposed these
consequences to provide an incentive
for affected sources to move swiftly to
comply with die final standards. In
response to die proposal, dirough
written comments from industry and
during round table discussions widi
45 In the HWC proposed rule, however, the
Agency allowed sources 90 days to submit test
results because D/F analyses can require more time
than traditional MACT analyses. We continue to
believe that this 90-day allowance is appropriate.
46 The Agency notes that under this scheme
.facilities are still subject to the RCRA emission
limitations, and the associated operating limits and
enforcement actions until removal of the air
emission limitations from the RCRA permit
However, because on the compliance date all
facilities must be compliance with the emission
standards of the final MACT rule, the Pre-COC
operating limits, which are expected to be more
stringent than current RCRA emission standards,
take precedence over the RCRA permit limits except
where the RCRA permit limits are based on a more
stringent standard adopted under the Omnibus
provisions of RCRA section 3005. Furthermore, EPA
notes that compliance with Pre-COC operating •
limits that are based on standards that are more
stringent than RCRA emission standards assures
compliance with the RCRA based emission
standards.
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
24237
affected parties, the Agency received
information suggesting that imposition
of these consequences through
regulatory language was unnecessary.
Consequently, the Agency is
considering deleting those specific
consequences from the regulatory
language and relying on the regulating
agency's policy regarding enforcement
response to. govern the type of
enforcement response at a facility that
fails to meet the compliance deadline.
Upon review of this enforcement
process, the Agency is presently
inclined to apply the normal CAA
enforcement procedures to non-
compliant sources-in the final rule for
hazardous waste combustors.
H. Compliance Requirements
In this section, we discuss several
compliance issues: (1) Compliance with
carbon monoxide (CO) and/or HC
emission standards; (2) compliance with
a startup, shutdown, and malfunction
plan when not burning hazardous
waste; (3) metals extrapolation and
interpolation considerations; (4) site-
specific variances for cement kilns and
LWAKs because of inability to meet the
standards solely due to metals or
chlorine in raw materials;,and (5)
emissions averaging for cement kilns
with unique design or operating
features.
A. Compliance With CO and/or HC
Emission Standards
The Agency proposed MACT
emission standards for both CO and HC
for incinerators and LWAKs as
surrogates to control emissions of
organic HAPs. Cement kilns would be
required to comply with either a CO or
HC standard because of raw material
considerations. See 61 FR at 17375-6.
The Agency explained that relying on
only CO or HC alone appeared to have
drawbacks, and thus proposed that
incinerators and LWAKs comply with
emissions standards for both.
Nonetheless, the Agency acknowledged
that requiring compliance with
standards for both CO and HC may be
unnecessarily redundant, and requested
comment on the following alternative
approaches: (1) Giving sources the
option of complying with either CO or
HC; or (2) establishing a MACT standard
for either CO or HC, but not both.
Although the Agency is continuing to
evaluate comments and options 47 on
. •"We are also evaluating another option whereby
compliance with the HC limit would be required,
and a site-specific CO limit (but not lower than 100
ppmv, the proposed MACT standard) would also be
established. This option would provide assurance
that HC emissions are within allowable levels, and
by also limiting CO, it would give the operator
how to limit CO and/or HC to control
organic HAPs, we invite comment on an
additional feature of the first option
whereby a source can elect to comply
with either the CO or HC standard.
Under this approach, a source that
elects to comply with the GO standard
(rather than the HC standard) would be
•required to document during the
performance test compliance with the
HG limit. This is necessary because we
have some (limited) data that show a
source can have HC levels exceeding the
standard discussed in today's notice
while meeting the CO limit Even
though the vast majority of the data
indicate that HC will be low when CCf
levels are low, a requirement to confirm
this relationship on a site-specific-basis
may be warranted.
To confirm the relationship during
. the performance test, the source would
use a portable HC monitor to document
that HC levels are below the MACT
standard. This is not expected to be a
burdensome test Further, however, to
ensure that the CO/HC relationship is
maintained over the range of operating
conditions that the facility may
ultimately employ, we are considering
whether to require the source to
establish limits on key. operating
parameters than can affect combustion
efficiency (and thus HC emissions). The
limits would be established based on
parameter values observed while
demonstrating the CO/HC relationship
during the performance test.
We specifically request comment on '
which key parameters should be limited
to ensure that the CO/HC relationship is
maintained. Further, we request
comment on whether these key
parameters should be identified on a
national basis or a site-specific basis ^
during review of the performance test
protocol. In providing comment, note
that the Agency has already proposed to
establish site-specific limits on several
combustion-related parameters to
ensure compliance with the D/F ;
emission standard (e.g., minimum
combustion chamber temperature;
maximum waste feedrate; and for batch
fed units, maximum batch size and
feeding frequency, and minimum
oxygen concentration in the combustion
gas). In addition, note that it may be
appropriate to identify as key
parameters (for purposes of ensuring
that the CO/HC relationship is
maintained) those parameters for which
limits are currently established during
destruction and removal efficiency
(ORE) testing, including: (1) Minimum
advance notice of a potential increase in HC levels,
thus helping to avoid an exceedance of the HC
standard.
combustion temperature at each
combustion chamber or'feed location;"
(2) minimum combustion gas residence
time (i.e., maximum combustion gas
velocity, or appropriate surrogate); and
(3) minimum combustion gas oxygen
concentration. If the Agency determines
that DRE testing is not necessary for
some types of sources as discussed In
Section in below, testing to document
the CO/HC relationship would be used
to establish limits on these heretofore
DRE-limited parameters.
B. Startup, Shutdown, and Malfunction
Plans
The Agency proposed that startup, ' -
shutdown and malfunction plans are
not necessary for hazardous waste
combustion sources because the
allowances that such plans provide are
not appropriate for hazardous waste
combustors (61 FR 17449). Specifically,
the Agency stated that EPA did not need
information regarding how quickly a
source is able to correct a malfunction
to come back into compliance with the
standards because affected sources
cannot burn waste unless the source is
in compliance with all applicable
standards.
However, in comments, the Agency
was informed of a few situations in
which it is appropriate for sources to
comply with a startup, shutdown, and
malfunction plan. These situations
include those in which sources
temporarily stop burning hazardous
waste but intend to resume burning
hazardous waste in the near future. The
examples presented to the Agency
Involve production units (i.e., cement
kilns, LWAKs, and possibly on-site
incinerators equipped with waste heat
boilers to generate steam or heat at a
chemical production facility) that must
continue operations following waste
feed cutoff to maintain production at the'
facility. Also, commenters cited
temporary shutdowns necessary for
planned maintenance to be performed
on the unit.
In light of these comments, the
Agency is rethinking Its proposed
approach and requests-comment on a
requirement for sources to comply with
the provisions listed in § 63.7 regarding
startup, shutdown and malfunction
plans, including the reporting
requirements of § 63.10(d) (5) (I). These
provisions would apply at HWCs when
waste is not being fed or does not
remain in the combustor, excluding
automatic waste feed cutoff events.
Sources would be subject to the
standards at all times, and the
malfunction plan would only apply
during times when the source is either
temporarily not burning waste or when
-------
24238
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
waste no longer remains In the
combustor. For example, If a source Is
temporarily not burning waste arid a
malfunction occurs that Is followed by
an exceedance of an applicable
standard, the source will not be In
violation as long as It Is complying with
the procedures outlined in the
malfunction plan. On the other hand, if
a source Is burning waste and a
malfunction occurs that necessitates an
automatic waste feed cutoff followed by
an exceedence of a standard, the source
would be in violation regardless of
whether the source is complying-with
the malfunction plan.48
Therefore, under this option, a source
may develop a malfunction plan that
details the situations in which the
source Is intentionally not feeding
waste, or that details the situations
when certain emission control devices
will not be in operation.
C. Metals Extrapolation and
Interpolation Considerations
In the NPRM, the Agency discussed
the operating conditions under which a
source will likely operate to
demonstrate compliance with the metals
emission limits identified in the
proposed rule (61 FRat 17428-30); The
Agency also acknowledged in the
proposal that operators will likely want
to operate their units during
comprehensive performance tests close
to the edge of the operating envelope so
that they can comply with the emission
standards and still achieve the
necessary operational flexibility
required by the facility. EPA further
stated that, to achieve a sufficient level
of operational flexibility, sources could
be expected to engage in the spiking of
metals into the waste matrix, which is
a practice that concerns the Agency.
EPA's concern extends to the overall
metals loading to the environment (for
example, Hg and Pb), exposure of
facility employees, and exposure of
surrounding community to higher than
normal metals concentrations due to
testing procedures that are for the
purposes of developing waste feedrate
limits and operational flexibility.
Therefore, the Agency has
Investigated approaches that may
provide a method to afford additional
metals feedrate flexibility without the
need of high metals spiking (otherwise
necessary to identify a metals feedrate
for an associated metals emission
level).49 One promising approach would
use a statistical extrapolation
methodology.50
Under this approach a source would
use the metal feedrates and emission
rates associated with a MACT
performance test to extrapolate to higher
allowable feedrates and emission rates.
The Agency believes that the upward
extrapolation procedure developed can
conservatively be used to allow for
higher metals feedrate limits, but still
ensure that the facility is well within
any applicable MACT (or RCRA)
emissions limit51 Although downward
interpolation (i.e., between the
measured feedrate and emission-level
and zero) was also investigated, the
Agency is concerned that downward
.interpolation may not be conservative
primarily because system removal
efficiency decreases as metal feedrate
decreases. Thus, projected emissions at
lower feedrates may in fact be lower
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rides
24239
CKRC notes that the Conference
Report for the Clean Air Amendments of
1990 S3 states that:
For categories and subcategories of sources
of hazardous air pollutants engaged in
mining, extraction, beneflciation, and
processing of nonferrous ores, concentrates,
minerals, metals, and related process
materials, the Administrator shall not
consider the substitution of, or other changes
in, metal- or mineral-bearing raw materials
that are used as feedstocks or materials
inputs,* * * in setting emission standards,
work practice standards, operating standards
or other prohibitions or requirements or
limitations under this section for such
categories and subcategories.
It should be noted that this language
is not reflected in the legislative text,
which states without caveat that MACT
standards may be based .on "process
changes, substitution of materials or
other modifications." CAA section
112(d)(2)(A)>However, assuming that
CKRC's request for these variances has
merit, and if the variances are
incorporated in the final rule, they
would apply to LWAKs as well given
that LWAK raw materials could also
cause those combustors to exceed the
standards using MACT control. We
solicit comment on whether these
variances are appropriate and workable,
and on the potential issues raised
below.55
1. Variance for metals or chlorine in
minerals and related process materials.
It may be appropriate to waive any
MACT standard for a metal or group of
metals or the standard for HC1/C12 if the
source documents that it cannot comply
with the standard while using MACT
control solely because of raw material
feed. As examples, MACT control for Hg
would be hazardous waste feedrate
control at a specified MTEC. MACT
control for SVM and LVM would also be
feedrate control at a specified MTEC
and compliance with the PM standard.
A condition of the variance could be
that the source would be required to
document that the concentration of
metal or chlorine (for which it is seeking
the variance) in hazardous waste and
any non-mineral feedstock is within the
range of normal levels for the industry.
This would ensure that metals and
chlorine emissions attributable to non-
mineral feedstreams are equivalent to
those from sources meeting MACT.
We therefore request comment on the
following issues:
• How would normal levels be
determined? What statistics should be
used? What should be the baseline year
for the determination (e.g., a given year
(2000, or the compliance date of the
rule)?
• Should the variance be granted only
if the hazardous waste and/or non-
mineral feedstreams have lower than
normal levels of metals or chlorine?
How much lower (e.g., 25th percentile
levels, 40th percentile levels)?
• Would it be necessary to establish
the normal levels hi the rule, or should
they be established initially, on a case-
by-case basis?
• Should the Agency be concerned if
levels of metals or chlorine in mineral ^
feedstocks decline over time thus *•'
enabling the source to meet the
standard? If so, what monitoring
approach would be appropriate to
identify when that occurred?
• When should variance petitions be
submitted to the State or EPA regulatory
officials (e.g., 120 or 180 days prior to
the compliance date)?
2. Variance for organics in minerals
and related process materials.
Although current BIF regulations
limit HC levels in kilns to 20 ppmv
irrespective of the source of the
hydrocarbons56 and the Agency
proposed to maintain that standard
under MACT, CKRC notes that some
sources have to operate inefficiently to
meet the standard. For example, a
source may have to operate back-end
temperatures at higher than normal
levels to oxidize enough of the organics
being desorbed to meet the HC standard.
This means that more fuel than normal
must be fired to provide the extra heat
at the back-end.57
CKRC has suggested approaches
whereby a source can document that
hazardous waste is being burned in
compliance with either the CO limit of
100 ppmv or the HC limit of 10 ppmv.58
In situations where the kiln can monitor
a representative sample of combustion
gas at mid-kiln at least temporarily
»H.R.Rep.No. 101-952, at p.339.101st Cong.,
2d Sess. (Oct. 26,1990).
54 CKRC cites additional authority in its letter to
B. Holloway and F. Behan (USEPA) of March 10,
1997 addressing these issues. Available in RCRA
Docket * F-97-CS4A-FFFFF.
s^To meet its RCRA mandate, the Agency would
continue to evaluate emissions under the omnibus
permit authority to ensure that controls were
adequate to protect human health and the
environment.
56 The Agency has acknowledged that HC in the
main stack of a long kiln can be generated by ^
desorpflon of trace organics in raw material '*
feedstocks as well as from fuel combustion.
57 Higher back-end temperatures may be
associated with Higher rates of D/F formation.
58 Neither approach would appear to be
appropriate for kilns that feed hazardous waste at
locations other than the clinker end. The concern
is that the kiln gas that is withdrawn for testing at
the mid-kiln location for compliance with the CO
or HC limit may not be representative of hazardous
waste combustion gases (i.e., either because the
hazardous waste is being fired downstream or, if the
waste is fired at mid-kiln, the waste combustion
gases may not be thoroughly mixed at the point of
kiln gas withdrawal for CO and HC monitoring).
during a performance test to document
compliance with the CO limit of 100
ppmv (or a HC limit of 10 ppmv),. limits
on key combustion parameters would be
established based on operations during
the performance test. The operating
limits would be continuously monitored
to ensure compliance with the CO or HC
limits. Limits on the following operating
parameters would be established: kiln
gas oxygen at the kiln outlet; kiln gas
residence time using raw material
feedrate as a surrogate; and combustion
zone temperature, using an appropriate
surrogate or measured at an appropriate
location.
CKRC also suggested that sulfur
hexafluoride (SF6) could be used as a
continuously monitored compliance
parameter in lieu of limits on other
parameters, except oxygen. This is
because SF6 is recognized as a
temperature labile compound—it is
more stable than most any other toxic
compound under a temperature-failure
mode of organics destruction. SF6 is
not, however, an indicator of oxygen-
deficient combustion failure modes—it
is destroyed at high temperatures
irrespective of oxygen levels. Given that
both adequate temperature and oxygen
are necessary for good combustion, an
oxygen limit as well as an SF6 feed limit
and emission limit would be established
under this option based on a
performance test documenting
compliance with either the CO or HC
.limits at mid-kiln.
Finally, CKRC suggested variance
approaches for the more problematic
situation where a kiln is not able to.
sample kiln gas at mid-kiln for
compliance with the CO or HC limit.
One approach would be to allow a kiln
to document compliance with the CO
limit of 100 ppmv or the HC limit of 10
ppmv in the main stack when burning
hazardous waste but temporarily
feeding imported, low organic raw
material. Under this approach, as with
the approaches discussed above,
operating limits on oxygen levels in kiln
gas at the kiln outlet, residence time of
combustion gas, and combustion zone
temperature would be established based
on a performance test using the low
organic raw material. Also, continuous
monitoring of limits on feedrates and
emission rates (based on performance
testing) of SF6 could be used in lieu of
establishing limits on residence time
and temperature.
E. Emissions Averaging for Cement
Kilns
Several cement kilns have unique
design or operating procedures that
warrant special consideration in
-------
24240
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
demonstrating compliance with the
MACT standards, as discussed below.
1. PreheaterorPreheater/Precalciner
Kilns with Dual Stacks. Some preheater
or preheater/precalclner kilns are
designed with separate main and alkali
by-pass stacks. To demonstrate
compliance with the emission standards
(other than the CO/HC standards where
compliance is based on emissions In
either the main or by-pass stack), It Is
appropriate to allow such kilns to
document either that both stacks meet
the applicable emission limits, or that
the stacks meet the limits considering
flow-weighted average emissions. This
is the approach currently used for
compliance for the PM NSPS, and it Is
appropriate as well for the MACT
standards that the Agency.has proposed.
2. Kilns that operate an in-line raw
mill. Some cement kilns vent the kiln
gas through the mill that grinds the raw
material (i.e., raw mill) to help dry the
raw material before charging to the kiln.
Such designs are referred to as "in-line
raw mills". When the raw mill is out of
service for maintenance, approximately
10% of the time annually, kiln gas by-
passes the mill and is vented to the
stack after passing through the PM
control device. (Stored milled raw
material is charged during these periods
of mill downtime.) The Cement Kiln
Recycling Coalition indicates that
emissions of HAPs that the Agency
proposed to regulate can be different
when gas is vented through the raw mill
versus periods of time when the mill is
out of service.59
It appears appropriate to base
compliance with the MACT emission
standards for such kilns on a time-
weighted average basis. Sources would
use historical information on utilization
time for the in-line raw mill to
document the time-weighted average
and would present this information to
regulatory officials as part of the test
plan. Further, sources would be
required to conduct performance testing
under both operating conditions: with
the raw mill on-line and off-line.
JJL ORE Testing Considerations
In the NPRM, the Agency proposed
that the 99.99 percent destruction and
removal efficiency (DRE) standard be
retained under RCRA.authority. See 61
FR at 17447. Although EPA could have
proposed the DRE requirement as part of
the MACT standards to help control
organic HAPs, the Agency explained
that doing so would have raised
significant practical implementation
concerns. This is because MACT
standards are generally self-
implemented by facilities to a large
degree whereas DRE testing has f
historically involved a detailed and -,
iterative process between a facility and
the regulatory agency.
The Agency received comments that *
raised other concerns, including: (1)
Whether it is necessary for a source to
actually perform a DRE test to ensure
.that it is achieving DRE;60 and (2) how
can the Agency ensure that RCRA DRE
testing is coordinated with MACT
performance testing.
The Agency has reconsidered DRE
testing issues and is today requesting
comment on options for ensuring
compliance with a DRE standard, and
how to coordinate DRE testing with
MACT performance testing.
A. Options for Ensuring Compliance
with a DRE Standard
The Agency has investigated whether
compliance with the CO or HC MACT
Standards would ensure that a source is
achieving 99.99% DRE 6I. The vast %
preponderance of the data indicate that
when a source is achieving CO levels
under 100 ppmv or HC levels under 10
ppmv, it is virtually always also
achieving 99.99% DRE.62 The Agency's
investigation noted, however, an
»» CKRC Comments. August 19.1996, pp 112-
113. Docket Number RCSP-0170.
60 The statutory minimum technology
requirement for incinerators (see RCRA 3004(o) (BJ)
requires the "attainment" of 99.99 percent
destruction and removal efficiency. DRE testing
could be replaced by an alternative that is equally
or more stringent (e.g., compliance with stringent
limits on CO or HC) to ensure attainment of 99.99
percent DRE.
41 The Agency evaluated approximately 455 DRE
test conditions, where CO was less than 100 ppmv
and 273 test conditions where HC was less than 12
ppmv. to determine if compliance with stringent
CO and HC limits would ensure that 99.99% DRE
was being achieved. Ten sources failed DRE even
though CO or HC levels were below 100 ppmv or
12 ppmv (on a run average basis), respectively. Nine
of the failures could be explained by: (1) Selecting
principal organic hazardous constituents (POHCs)
that were also common products of incomplete
combustion; (2) feeding low concentrations of
POHCs (a phenomenon of DRE testing is that it is
very difficult to measure 99.99% DRE when POHCs
are fed at low concentrations, even though emission
concentrations may be trivial); or (3) feeding
aqueous waste with such low concentrations of
organics that, even under poor combustion
conditions, the waste did not generate high levels
of CO or HC. See USEPA. "Draft Technical Support
Document for HWC MACT Standards (NODA),
Volume II: Evaluation of CO/HC and DRE
• Database", April 1997.
<*• It could be argued that this is due to two ,^
factors: (1) during successful DRE testing many
sources operated at CO or HC levels that were weU
below the 100/10 levels; and (2) it is not clear that
those sources would continue to achieve 99.99%
DRE at higher CO orHC levels (but not exceeding
the 100/10 levels). This is unlikely to be a major
concern, however, because combustion devices
operating at CO levels under 100 ppmv are
generally considered to be operating under good
combustion conditions that would ensure 99.99%
DRE in any event.
atypical, failure mode for the CO/HC
versus DRE relationship: when low
organic content waste is fed into a
region of a combustor other than the
flame zone (e.g., into an unfired
afterburner). .One test condition of the
approximately 455 investigated failed
the CO/HC versus DRE relationship for
this reason. This was a highly unusual
test condition, and does not represent
good combustion practice. CO levels
were likely low because flame
combustion was not occurring, and HC
was likely low because the waste could
. have had only trace levels of toxic
organics that did not contribute .
significantly to the HC loading (but
which could nonetheless pose a health
or environmental hazard).
Given the general relationship
between CO, HC, and DRE and the
highly unusual nature of the lone
exception, the Agency is considering
.whether DRE testing is warranted in all
cases for sources complying with the
MACT CO and HC standards. The DRE
test is a complicated, expensive test. In
addition, although It can help indirectly
to ensure that a source is operating
under good combustion conditions, it
may not provide the operationally direct
level of assurance of good combustion
•conditions that CO or HC does. The data
show that sources can be achieving
99.99% DRE even though CO or HC
levels exceed values considered to
represent good combustion (i.e., CO of
100 ppmv, HRA, and HC of 10 ppmv,
HRA).«
Accordingly, the Agency is
considering three options for reducing
the DRE testing burden, as discussed
below.64 Under all options where DRE
testing would be waived, a source
would have to be in compliance with
the final MACT standards for CO/HC,
which will be sufficient to show ensure
compliance with the DRE standard as
well."
• ** Under an option the Agency is considering for
establishing MACT standards for CO and HC, a
source would be able to elect whether to comply
with either the CO or HC standard. Although CO
is not a direct measure of HC emissions, the Agency
is considering requiring sources that elect to
comply with the CO standard to document that
their HC emissions also meet the standard.
64 The Agency's analysis to date has focused on
the 99.99% DRE standard. We have not investigated
whether sources that bum "dioxin-listed waste"
under§264.343(a)(2) and are required to ,
demonstrate 99.9999% DRE are likely to achieve
that DRE when operating under stringent CO and
HC levels. Given that there are few HWCs that are
permitted to manage such wastes and given the
high toxidty potential of such wastes, the Agency
is inclined to continue to require DRE testing at
facilities handling those wastes.
65 Long cement kilns generally cannot meet the
stringent CO and HC limits applicable for waste
combustion (i.e., 100/10 ppmv) because of organics
in raw materials. Thus, the Agency proposed that
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
24241
B. DRE As a MACT Versus RCRA
Standard
In Investigating approaches to ensure
coordination of DRE testing with MACT
performance testing, the Agency has
reconsidered whether the DRE standard
could be effectively implemented as a
MACT standard (to help control organic
HAPs). To ensure coordination of DRE
and MACT performance testing, the
Agency is considering extending the test
plan review period from the proposed
60 day period (see proposed
§ 63.1208(e) and § 63.7(b) (1)) to one year
to allow regulatory officials time to
consider DRE testing in context with
MACT testing. With this opportunity for
coordinating the testing, the Agency's
concerns expressed.at proposal about
the difficulty of implementing the DRE
standard under the self-implementing
regime of MACT may be largely
overcome (i.e., if the Agency
incorporates into the MACT standards
opportunity to review and approve the
DRE test protocol). Thus, the Agency is
considering incorporating the DRE
standard as a MACT standard.
Sources wishing to perform a
combined DRE and comprehensive
performance test would have to submit'
the test plan one year in advance of the
test. If the review requires more than
one year, the Agency can extend the
testing date for coordination purposes
(assuming the source has made a good
faith effort to cooperate with regulatory
officials to identify an appropriate test
protocol). However, there would be no
extensions granted for the initial
comprehensive performance test
because it is imperative that sources
document compliance with the MACT
emission standards (including those for
the high priority HAPs, D/F, Hg) on
schedule. Sources wishing to perform a
combined initial comprehensive
performance and DRE test would
therefore have to be diligent in working
with regulatory officials to ensure that
such kilns comply with a CO level of 100 ppmv or
a HC level of 20 ppmv. Notwithstanding the
inability to document good combustion conditions
by complying with stringent CO/HC limits, the •
Agency believes that cement kilns that fire
hazardous waste into the clinker end of the kiln
will virtually always achieve 99.99% DRE because,
to make marketable products, clinker temperatures .
must be approximately 2700° F, and combustion gas
temperatures are typically several hundred degrees
hotter than the solids temperature. .These
temperatures are theoretically high enough to
ensure destruction of organic compounds in the
waste. Consequently, such kilns should not be
precluded from the waivers discussed in the text.
If such a kiln were to inject hazardous waste at
nonflame zone locations such as mid-kiln or at the
raw material end of the kiln, however, we are
concerned that DRE may not always be achieved.
The kiln would not be eligible for the DRE waiver.
the combined test protocol is developed
and approved in a timely manner.66
The Agency invites comment on these
issues, including whether DRE should
be incorporated as a MACT standard,
and irrespective of that decision,
whether a one-year review period
provides adequate opportunity to
review a combined DRE test and
comprehensive performance test
protocol.
IV. Notification and Reporting
Requirement Considerations
A. Public and Regulatory Notification of
Intent to Comply
In the proposed rule, the Agency
requested comment.on strategies to
encourage or require affected sources to
. comply with the final emissions
standards at the earliest possible date.
The Agency also asked for views on
methods that could be used to
determine when a source could "*'
realistically conclude whether it will
comply in a timely fashion with the
final standards (61 FR at 17416). A
number of commenters argued for the
Agency to require a submission from
affected sources that identifies whether
and how the facility intends to comply
with the final standards. This
notification requirement was referred to
as a "Notification of Intent to Comply."
The purpose of the submission would
be to identify the sources that will not
comply'with the final standards so that
those sources could be forced to
terminate waste burning activities as
soon as possible following the effective
date of the final HWC rule.
Other commenters, responding to our
request for comment regarding the
proposed permit modification options
(61 FR at 17455), suggested that all
facilities be required to submit a plan
that outlines the procedures each *,
facility intends to follow to comply with
the final standards. However, the
purpose of this submission would be to
begin an early process of
communication between the public and
the facility through the public
disclosure of the facility's compliance
strategy.
The Agency has reviewed these
comments and supports the goals and
66 The Agency also considered requiring sources
to submit draft test protocols one year prior to the
test date, regardless if the comprehensive
performance test is to be combined with a DRE
demonstration. We determined that may not be
appropriate, however, because normal
comprehensive performance tests should not
require a review process longer than provided by
the CAA-MACT general requirement. Therefore, the
one-year test review period would only apply for
those sources that wish to coordinate the
comprehensive performance (or confirmatory) test
with a DRE test.
purposes of a requirement that compels
sources to identify their intentions to
comply with the final rule, and to
describe how they will achieve that
compliance. Furthermore, the Agency
supports any process that promotes
public notification and interaction with
respect to a hazardous waste
cbmbustor's future operations. To the
extent that some limitations on public
participation would be the result of a
streamlined permit modification process
that may be finalized ahead of the HWC
MACT rule, promotion of early public
notification and intervention in this part
of the rule is appropriate and desirable
given our general policies in that regard
(see, e.g., RCRA Expanded Public .
Participation Rule, 60 FR 63417 (Dec.
12,1995)). Therefore, the Agency is
considering a notification requirement,
based on and growing out of ideas that
were presented in comments, that may
be applied to sources affected by the
final rule. This notification requirement,
called the Public and Regulatory
Notification of Intent to Comply
OPRNIC), would involve the facility
submission and public disclosure of a
plan that relates to whether and how the
facility intends to come into compliance
with the final standards.
However, due to enforcement and
implementation issues, the Agency is
concerned that it is not feasible to use
a submission that identifies only a
facility's future "intentions" as the legal
basis to force a facility to terminate
waste burning activities before the
statutorily based compliance period of
three years. Moreover, any official
review and approval of such
submissions could conceivably slow
down the rate at which facilities come
into compliance with the final
standards. This would thwart the
objectives of a streamlined permit and
compliance process.
The Agency believes that the most
effective application of such a
submission is to promote public
awareness, as well as discussion
between a facility and its community, ••
which will afford them an opportunity
to engage in discussions regarding the
details of the facility's plans to comply
with the final standards. However, the
Agency does not intend for this
submission to undergo a formal review
by the regulatory agencies involved.
The Agency requests comment on this
option which requires sources to .
prepare and submit for public comment
a notification identifying the source's
intentions to comply with the final rule
as well as the strategy they intend to
follow to assure compliance by the
compliance date. This notification
requirement would apply to all sources
-------
24242
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
burning waste on the effective date of
the final HWC rule, and would require
sources to prepare a draft notification,
announce the availability of the draft
notification as well as a future informal
public meeting to discuss the draft
notification, hold an informal public
meeting, submit die final .notification to
all appropriate regulatory agencies, and
update the notification as necessary.
The Agency intends for the
information contained in die draft
notification to provide enough detail so
that the public can engage in a
meaningful review of die facility's
compliance strategy. For example, if in
die draft notification a facility identifies
and describes the type(s) of control
technique® being considered, die
facility should Include, as appropriate,
waste minimization and/or pollution
control opdons that may have been
evaluated.
EPA also requests comment on a
requirement for affected sources to hold
at least one informal meeting witii die
public before submitting die final
notification to die appropriate
regulatory agencies. The goal of tills
Informal meeting Is to provide a forum
to facilitate dialogue between die
affected source and its community. The
meeting should provide an open,
flexible and informal occasion for die
facility and die public to discuss various
aspects of die facility's compliance
strategy because It provides die public
direct input to die facility owners/
operators. In addition, die meeting
affords facility owner/operators die
opportunity to gain an understanding of
die public's expectations, which can
dien be addressed and included in die
facility's final submission. The Agency
anticipates that die facility arid die
public will share Ideas, educate each
other, and continue to establish a
framework for sound communication.
However, as suggested in comments
received from CKRC,67 die Agency
understands that die early timing of die
meeting may affect a facility's ability to
have complete or fully accurate
Information, but die Agency belie
tiiat die benefits of early public
Involvement and access to information
outweigh die drawbacks of incomplete
information. Furthermore, die time
period between die effective date of die
HWC rule and die informal meeting
announcement should provide a facility
sufficient time to collect, analyze, select,
and plan a compliance strategy.
However, comments are invited on
other appropriate time periods between
leves
"Memorandum, from CraJg Campbell (CKRC) to
Mitlhcw Halcjr. (EPA), regarding compliance plans
under the HWC MACT Rule, dated March 18,1997.
die public notification and die informal
public meeting, and on die time period
necessary to collect the information
required for die PRNIC.
Another timing issue relates to when
a facility should notify the community
regarding die availability of die draft
PRNIC. At tills stage, die Agency is
considering to require that die
notification be made on or before 210
days following the effective date of die
final HWC rule. This would necessitate
tiiat an announcement of die informal
public meeting and die availability of
die draft PRNIC be made 30 days prior
to die meeting in a manner that is likely
to reach all affected members of die
community. The Agency is considering
that tiiis announcement, of the informal
public meeting and draft PRNIC *»
availability, should be required in three
ways: As a display advertisement in a
newspaper of general circulation; as a
clearly marked sign on die facility
property; and as a radio broadcast. Each
of these notices would have to include
die date, time and location of die
meeting, a brief description of die
purpose, a brief description of die
facility, a statement asking people who
need special access to notify die facility
in advance, and a statement describing
how die draft PRNIC can be obtained.
The Agency requests comment on this
approach that requires facilities to hold
an informal public meeting prior to die
submission of die final PRNIC to die
regulatory autiiorities.
An additional requirement of the
notification approach being considered
involves the submission, to die
appropriate regulatory agencies, of die »
final PRNIC 270 days following die
effective date of die final HWC rule. The
submission would contain the following
information: The name and location of
die owner operator; die location of die
source; a statement as to whedier die "'
source is a major or area source; a
description of any waste minimization
and pollution control technique(s)
considered; a description of the
emission monitoring technique (s)
considered; a description of die waste
minimization and pollution control
technique(s) effectiveness; a description
of die evaluation process used to select
the waste minimization and/or '
pollution control technique(s); and an
outiine of die key dates in die process
tiiat die facility plans to follow to
implement die selected waste
minimization and/or pollution control
technique(s). This submittal should also
capture die major comments or ideas
tiiat were discussed in die public
meeting or that were submitted in
response to die release of the draft
PRNIC.
The final requirement of die
notification approach being considered
involves updates to the final PRNIC
following a significant change in die
facility's implementation strategy. A
significant change would be analogous
to a change diat would trigger a RCRA.
class two or class tiiree permit
modification request, and would apply
only to changes tiiat depart from die
strategy described in die final PRNIC.
Examples of some changes that may be
considered significant changes are as
follows: A change in die pollution
control technique to be implemented; a
request for permit modification; a
request for an extension of die
compliance date; or a decision to stop
or to continue burning waste that is
contrary to die final PRNIC.
Additionally, all sources could be
required to notify the public via a
mailing to die facility's mailing list
witiiin 30 days following a
determination tiiat a significant change
has occurred in die facility's
implementation strategy. The change
would have to be described in writing
and made available to requesting parties
via placement.in an information
repository or tiirough direct transmittal.
This requirement would be in keeping
witii the spirit of die PRNIC, which is
to keep die public informed of any
significant changes in die facility's
compliance and implementation plan.
The Agency invites comment on this
submittal and die submittal process, and
requests information on die benefits and
burden associated with such a process.
The Agency specifically invites
comment on die use of permit
modification criteria to identify a
significant change tiiat would
necessitate an update to die PRNIC.
B. Data Compression Allowances
The Agency is considering allowing
the use of data compression techniques
in die recording of continuously
monitored parameters under tiiis rule.
This is in response to comments on die
proposed rule regarding die additional
burden associated witii the proposed
monitoring and recording requirements
and specific requests to allow data
compression. We are also considering
revisions to parts 264, 265 and 266 tiiat
would be conforming revisions to
ensure tiiat die RCRA rules are
consistent widi similar provisions of die
proposed part 63 rules.
Commenters raised the issue of an
additional burden by the proposed
monitoring and recording requirements.
We do not agree tiiat die proposed
requirements pose significant additional
record keeping burdens from current
regulations (i.e., BIF rule) or existing
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
24243
permit requirements under RCRA.
However, we are interested in reducing
the Information burden—for example,
how much is recorded if the data is-
automatically evaluated under an
established set of specifications, while
maintaining the integrity of the data for
compliance evaluation purposes.
Briefly, data compression is the.
process by which a facility
automatically evaluates whether a
specific data point needs to be recorded..
' Data compression does not represent a
change in the continuous monitoring ,
requirement proposed in rule. One-
minute averages will continue to be
generated. However, with data -
compression, each one-minute average
will be automatically compared with a
set of specifications to decide the need
for recording. New data is recorded
when the one-minute average value falls
outside the set of specifications.
This option should provide a good
opportunity to the regulating agencies to
focus their review of operating data,
because facilities using data
compression will record data that is
indicative of non-steady state operations
more frequently than steady state
operations. This will significantly
reduce, up to 90%, the data subject to
review by the regulating agency as the
facilities' self-evaluate, under a
previously approved set of
specifications, the data being recorded.
The dynamics of monitored '
parameters are not uniform across the
regulated universe, and establishing
national specifications for data
compression techniques in this rule may
not be feasible. Different data
compression techniques can be
successfully implemented for a
monitored parameter to obtain
compressed data that reflect the
performance on a facility specific basis.
As a result the Agency is considering
allowing the sources to request the
regulatory agency to use data
compression techniques that reflect site-
specific conditions of the monitored
parameters and establish data
compression specifications accordingly.
Upon approval, sources may start data
compression techniques based on the
approved set of specification.
At a minimum, a source
implementing data compression will be
required to record a value once every
ten minutes. In combination with the
appropriate set of specifications, a «
recorded value every ten minutes will
result in a potential data recording
reduction up to 90%.
As a guideline, for the regulating
agencies and sources EPA has
developed a table to use as a guideline
developing site-specific specification for
data compression techniques. These are,.
the basis for the specification in the
table:
1. Data compression limit. The closest
level to a permit limit/standard at which
reduced recording is allowed. Within
this level, minute-by-minute data
recording is required. The data
compression limit should reflect a level
at which the specific parameter is
unlikely to exceed its permit limit
within a one-minute change. The other
consideration is to seta data
compression limit at which owners and
operators can practically implement
data compression.
2. Fluctuation limits. The permissible
deviation of new data value from
previously generated value. This
parameter is a reflection of tolerance of
the agency to allow a parameter to
change without requiring the data point
to be recorded. The considerations to
establish the fluctuation limits are (1)
The potential of the regulated parameter
to change in one minute and cause an
exceedance of the permit limit on a
rolling average basis and; (2) the
maximum variation tolerated from a
change of other related operating
parameters (i.e., fuel and temperature,
gas flow and APCD parameters).
We invite comment on allowing data
compression under this rule, including
revising parts 264, 265 and 266, and on
the following table:
FLUCTUATION AND DATA COMPRESSION LIMITS EXPRESSED AS PERCENTAGES OF THE PERMIT/STANDARD LIMITS
Device
OEMS
GEMS
OEMS
OEMS
GEMS
Activated carbon injection
Dioxin inhibitor *
Catalytic oxidizer
Good combustion and APCD efficiency ...
Feed control
Wet scrubber
Ionizing wet scrubber
,
Drv scrubber
Parameter
Patiiculate matter . ...........:..
Carbon monoxide 1 hour
Total hydrocarbon
Total mercury 10 hour
Multi-metal 10 hour
HCI
Chlorine
Max inlet temperature to dry PM APCD ....
Min carbon injection feedrate (carbon feed through injector) ....
Min carrier fluid flowrate or nozzle pressure drop
Min inhibitor feedrate ;..
Min flue gas temperature at entrance
Max flue gas temperature at entrance
Maximum waste feedrate ."i.
Min combustion chamber temperature (exit of eacfi chamber)
Maximum flue gas flowrate or production rate
Maximum total metals feedrate (ail streams)
Maximum pumpable liquid metals feedrate
Maximum total ash feedrate (all streams)
Maximum total chlorine feedrate (all streams)
Minimum pressure drop across scrubber ..«
Min liquid feed press
Minimum liquid pH
Min blowdown (liquid flowrate) or max solid content in liquid ...
Minimum liquid flow to gas flow ratio
Minimum pressure drop across scrubber ...;
Minimum liquid feed pressure
Min blowdown (liquid flowrate) or max solid content in liquid ...
Minimum liquid flow to gas flow ratio
Min power input (kVA: current and voltage)
Min sorbent feedrate
Ructuation
limit ±
10%
10 DDm
2 DDITI . .
10%
10%
10%
10%
10° F
5%
20%
10%
20° F
20° F
10%
'20° F
10%
10%
10%
10%
0.5" water .
20%
0.5 pH unit ...
5% :
10%
0.5" water ....
20%
5%
10%
5%
10%
Data compression
limit
60%
50 DDm.
60%
60%.
60%.
60%.
60%.
Limit -30°F.
Limit +20%.
Limit +25%.
60%.
Limit +40° F
Limit -40° F.
60%.
Limit +50° F.
60%.
60%
60%.
60%.
Limit +2".
Limit +25%.
Limit + 1 pH unit.
Limit +20%.
Limit +30%.
Limit +2" water.
Limit +25%.
Limit +20%.
Limit +30%.
Limit +20%.
Limit +30%.
-------
24244
Federal Register / Vol. 62, No. 85 / Friday. May 2, 1997 / Proposed Rules
FLUCTUATION AND DATA COMPRESSION LIMITS EXPRESSED AS PERCENTAGES OF THE PERMIT/STANDARD LIMITS—
Continued
Device
Fabric fSter
ESP
Parameter'
Minimum carrier fluid flowrate or nozzle pressure drop
Min power input (kVA: current and voltage)
Fluctuation
limit *
10%
1" water
5%
Data compression
limit
Limit +30%.
Limit +2" water.
Limit +20%.
V. Waste Minimization and Pollution
Prevention
A. Overview
Amendments to RCRA In 1984, and
the Pollution Prevention Act of 1990
establish a clear national policy
preference for pollution prevention and
environmentally sound recycling as the
nation's top priority environmental
management methods, over treatment,
storage and disposal. Pollution
prevention, also referred to as source
reduction, includes any practice that
reduces the amount of pollutants
entering a waste stream, prior to
recycling, treatment or disposal. Waste
minimization, a term particular to RCRA.
and EPA's hazardous waste program,
Includes pollution prevention (or source
reduction) and environmentally sound
recycling. Combustion for treatment or
destruction is a form of treatment, and
is not included in the definitions of
pollution prevention, source reduction,
waste minimization and/or
environmentally sound recycling.
Based on previous studies, stringent
limits on pollution control devices
generally provide a strong incentive for
companies to pursue less costly waste
minimization measures to achieve
compliance. The implementation of the
Land Disposal Restrictions program has
shown this to be the case in the RCRA
program. Waste minimization measures
can, in many cases, provide companies
with a variety of benefits, including:
improvements in production yields,
reduced worker exposure, reduced
waste volumes, reduced waste
management costs, reduced liability,
and reduced compliance burdens. As a
result, many companies, including those
affected by today's rulemaking, have
made significant progress identifying
and installing waste minimization
measures that result in one or more of
these benefits. In addition, hazardous
waste generators that transport waste
off-site for treatment, storage or disposal
are required to certify on each
hazardous waste manifest that they have
a waste minimization program in place.
In addition, facilities that have a RCRA
permit to treat, store or dispose of
hazardous wastes are required to certify
annually that they have a waste
minimization program in place (See •
sections 3002(b) and 3005(h) of RCRA).
Past studies indicate that existing
regulations can also contain inherent
barriers that prevent companies from
identifying and installing additional
waste minimization measures that could
be cost effective and provide an
alternative or supplemental means to
achieve compliance. Potential w
regulatory impediments can include:
Tight compliance deadlines that
preclude taking extra time to explore
waste minimization alternatives,
perceptions that end-of-pipe technology
is preferred by government agencies
over less well known waste
minimization measures to achieve
compliance, a tendency to continue
relying on pollution control technology
once a company has sunk available
capital into end-of-pipe controls, and a
lack of government willingness to
explore more flexible compliance
approaches.
During extensive interaction with
public stakeholders during the
development of EPA's Hazardous Waste
Minimization National Plan (released in
1994), some companies emphasized that
short compliance deadlines after the ^
promulgation of end-of-pipe standards
are a significant impediment to fully
identifying and installing waste
minimization measures that could either
replace or supplement end-of-pipe
pollution control measures that may
still be necessary. As a result,
companies are likely to opt for installing
"end-of-pipe" pollution controls to meet
compliance deadlines, instead of
pursuing waste minimization and
pollution control measures as a
compliance approach. At large complex
manufacturing facilities (such as
chemical manufacturing plants), short
compliance deadlines are a particular
barrier since completing a waste
minimization options assessment
requires consideration of chemical
reaction redesign, testing and
installation. In contrast end-of-pipe
controls can often be installed more
quickly than waste minimization
process changes, even though they may
be more expensive. In addition, once
capital has been sunk into end-of-pipe
pollution controls, there is little **
incentive for companies to then spend
money exploring pollution prevention/
waste minimization options that would
offset the need for the end-of-pipe
controls. This factor is one of the major
factors to consider in today's
rulemaking. This is discussed in more
detail below.
B. EPA Proposed Flexible Waste
Minimization Incentives
EPA was aware, in its April 1996
proposal for this rulemaking, that
promulgating MACT standards may
contain some inherent barriers to
identifying and installing waste
minimization technologies that could be
more cost effective for meeting
environmental protection standards (in
some cases) than end-of-pipe air
pollution control equipment alone.
Consequently, EPA requested comment
on three regulatory incentives that could
partially offset potential barriers and
provide regulated companies with an
increased opportunity to identify and
install waste minimization technologies
that reduce or eliminate hazardous
waste entering combustion feed streams
as a cost effective approach to
compliance. EPA's objective in this
effort is to promote flexibility in the use
of waste minimization measures that
would reduce the amount aind/or
toxicity of hazardous wastes entering
combustion feed streams, either as an
alternative to end-of-pipe combustion
measures, or in combination with
combustion measures, to meet MACT
standards.
EPA requested comment on two
approaches that use waste minimization
facility planning to identify cost
effective waste minimization measures
dial reduce hazardous wastes entering
combustion feed streams. Waste
minimization planning has been used in
over 20 states as a method to encourage
companies, particularly those that
generate and manage wastes on site, to
identify cost effective waste
minimization measures that can be used
in place of, or in combination with, end-
of-pipe pollution control measures. Of
the 21 commercial incinerators and the
141 on-site hazardous waste
incinerators facilities known to be
covered by today's rule, 43-44 percent
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
24245
of the facilities are in states that have
mandatory waste minimization
planning programs; 14 percent are in
states that have voluntary waste
minimization planning programs; and
42-43 percent are in states that do not
have formal waste minimization
. planning programs.
The first waste minimization facility
planning approach proposed for
comment sought to encourage facilities
to reduce the amount of hazardous
waste entering combustion feed streams
as much as possible through cost
effective waste minimization measures.
The proposal sought to accomplish this
objective by requiring all facilities
covered by this rulemaking to provide to
the appropriate EPA .or State permitting
authority adequate information on waste
minimization measures that would
reduce hazardous wastes entering
combustion feed streams. Requiring
facilities to formally consider cost
effective waste minimization options
would raise the likelihood that
hazardous waste generation could most
cost effectively be reduced at the source
or recycled, as a preferred approach to
combustion. Since many of these
facilities are located in states that have
mandatory or voluntary waste
minimization planning programs, EPA
hoped to build on a process already in
place. States that have mandatory waste
minimization planning programs
generally require facilities to provide a
description of changes in process
equipment, raw materials, materials
handling, recycling, maintenance or
other changes that would reduce the
amount and/or toxicity of wastes that
are treated or disposed. None of the
existing mandatory or voluntary State
waste minimization planning programs
specifically address reductions of
combusted hazardous as an objective of
the planning process. EPA requested
comments on this approach to
determine if the approach could provide
greater flexibility for facilities to build
, on requirements of existing state
programs to achieve compliance with
MACT standards.
In the second waste minimization
planning option, EPA proposed to
provide EPA Regions and States with
the discretionary authority to make case
by case determinations regarding which
facilities would be required to provide
information on waste minimization
alternatives to reduce hazardous wastes
entering combustion feed streams. This
determination could take into account
several factors, including, for example,
whether an existing state program had
already accomplished the equivalent of
this objective, the extent'to which this
requirement may be too burdensome for.
some states, and the extent to which
facility specific conditions indicate
emissions could be best controlled by ""
feed stream management and waste
minimization at the source.
The third waste minimization
incentive EPA proposed for comment
allows facilities to apply for up to a one
year extension to the thitee year .
compliance period allowed under the
CAA and 40 CFR 63.6(i)(4)(i)(A) in cases
where facilities need additional time to
identify and install waste minimization
measures that would reduce hazardous
wastes entering combustion feed
streams as a method (either alone or in
combination with combustion or other
treatment technology) to achieve
compliance. 40 CFR 63.6(i)(6)(i)
describes the requirements for j,
requesting a compliance extension. A
request m'ust include a description of
the pollution control, process changes '*
or process equipment to be installed, a
compliance schedule that describes the
dates by which these controls, process
changes and process equipment will be
initiated, the dates by which installation
will be completed, and the date by
which compliance will be achieved. The
Administrator or a State that has an
approved Part 70 permit program or has
been delegated the authority to
implement and enforce the emission
standard for that source may grant such
extensions. This incentive would, at
least in part, offset some of the time
barriers large companies might need to
fully explore and install waste
minimization options in addition to any
combustion equipment that may still be
necessary.
C. Comments Received
EPA received comments on waste
minimization from 22 commenters.
Companies that operate on-site units
(many of which are large chemical
•plants) commented that, while waste
minimization can provide a cost
effective approach to compliance,
neither the three year compliance
period allowed for this rule, nor the
three years plus a one year extension is
sufficient time to complete the two track
task of designing, testing and installing
waste minimization process changes
that reduce hazardous wastes entering
combustion feed streams, and designing
and installing any combustion or other
treatment equipment that may
nevertheless be necessary. Waste .
minimization is an on-going process
that should be continually under
investigation in all companies.
However, EPA agrees that in cases
where standards are promulgated that
change the economics of how much
pollution can be emitted to the
environment, even on-going waste
minimization programs may not be able
to anticipate the best combination of
waste minimization and treatment
measures to achieve compliance. EPA
agrees that in some cases, particularly at
large complex manufacturing
operations, the three year compliance
period may not be sufficient time to
consider waste minimization measures,
and in other cases, three years plus a
one year extension may not provide
sufficient time.
Commercial facilities continue to
assert that they have few direct
opportunities to pursue waste
minimization since they have little
control over the wastes generated by
their customers. Some commercial
companies believe EPA should
implement "good actor" incentives for
companies that educate their customers
regarding available waste minimization
resources. Such incentives could
include reduced inspection frequencies,
.reduced performance testing, and a
recognition program. EPA agrees that
commercial combustors of hazardous
waste have .little direct control over the
wastes generated by their customers and
therefore will experience little if any
flexibility from any the waste
minimization incentives proposed for
comment. The comment to implement
good actor incentives as an incentive for
commercial companies to educate their
customers on waste minimization did
not contain sufficient information to
determine the merits of such an
approach. EPA does point out, however,
that this type of concept, i.e., one in
which private industry proposes an
improvement in environmental
performance through and innovative
regulatory approach, is the type of
approach that might be appropriate for
further exploration at a later time.
Three states commented. Two states
believe EPA should encourage waste
minimization in this rulemaking.
However, they believe three years plus
a one year extension may not be enough
time for companies to identify and
install waste minimization measures.
The third state said that waste
minimization Incentives should not be
necessary in this rule because
companies have had many years to
pursue waste minimization programs
and should have already considered
waste minimization as an approach to
compliance. EPA agrees with the two
states that, in some cases, three years
plus a one year extension may not be
sufficient time to identify and install
waste minimization measures that
achieve compliance. EPA agrees with
the third state to a limited extent in that
companies have had many years to
-------
24246
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1T997 I Proposed Rules
Implement waste minimization
programs, and notes that most, if not all,
of the companies affected by today's
rulemaking probably have waste
minimization programs in place.
However, as noted earlier, waste
minimization is an on-going process,
and the stringent requirements of the
MACT standards for hazardous waste
burning facilities may shift the
economics for particular companies in a
way that makes certain waste
minimization measures more cost
effective than they otherwise would
have been, and companies may need
additional time, to design and install
these approaches.
EPA's Interim Final Guidance to
Hazardous Waste Generators on the
Elements of a Waste Minimization
Program in Place (May 28,1993)
recognizes companies make these
determinations on a case by case basis.
EPA's guidance describes six general
program elements that contribute to
successful corporate waste
minimization programs. These elements
include: (1) Top management support
that emphasizes waste minimization in
its corporate policy, employee
involvement and rewards for ideas that
reduce waste generation, setting goals
for waste reduction, and other proactive
management steps; (2) characterization
of waste generation and waste
management costs, identification of
sources of waste in the production
process, how they were generated, the
value of raw materials and lost products
that are escaping as waste, and the cost
of replacing and managing wasted
materials; (3) periodic waste
minimization assessments that are tied '
into other efforts to improve
environmental management; (4) a cost
allocation system that assigns the true
cost of generating and managing wastes
to the activities that generate the waste
in the first place; (5) encourage
technology transfer that shares ideas
and technology between parts of the
organization and with other
organizations where appropriate; and (6)
program Implementation and evaluation
that evaluates successes and failures,
and shares information with the public.
While these principles were published
in regard to RCRA's waste minimization
certification requirement, the principles
can be used as relevant guiding
principles by companies who wish to
consider using waste minimization
measures as a method to reduce
hazardous wastes entering combustion
feed streams regulated under MACT
standards and the Clean Air Act
One company argues in its comments
diat mandatory waste minimization
planning should be made a MACT
requirement so that facilities are forced
to consider source reduction and
recycling alternatives, rather than
simply installing end-of-the-pipe
equipment to control HAP emissions.
The company argues that this approach
would be particularly useful in
controlling combustion feed streams to
limit the combustion of metals and
other constituents that can not be,
adequately controlled using end-of-pip*
measures.
EPA has examined this issue closely.
While mandatory facility planning on
'the surface may appear to force facilities
to consider waste minimization
solutions, providing appropriate
regulatory incentives and harnessing the
power of public dialogue for companies
to identify and install waste
minimization measures will result in
more waste minimization measures.
Sixteen states have implemented
mandatory waste minimization
planning programs and several more
have implemented voluntary waste
minimization planning programs in an
effort to encourage facilities to pursue
waste minimization measures over end-
of-pipe measures. A Federal mandatory
and prescriptively detailed waste
minimization planning requirement
would be, at best, marginally effective in
causing large companies (which make
up the population of facilities affected
by today's regulation) to identify and
install waste minimization measures
beyond what they would do under
current requirements. Large companies
generally already have the necessary
staff, information, and resources to
pursue waste minimization alternatives
where it makes sense to do so. Whether
large companies choose waste
minimization solutions over end-of-pipe
solutions depends on a variety of
economic and other factors that
outweigh attempts to identify additional
waste minimization alternatives. EPA
hopes to encourage minimizing
impediments to waste minimization by^
soliciting comments on the approaches
contained in today's NODA.
Furthermore, the remaining States have
chosen to not implement mandatory or
voluntary waste minimization planning
programs. Some States believe that •
mandatory waste minimization
planning does not improve waste
minimization results. It would not be
appropriate for EPA to eitiier add
additional burden to State waste
minimization programs that already
exist or to States that have chosen not
to have waste minimization planning
programs.
EPA is, instead, asking for comment
on a refined approach that encourages
facilities to consider waste
minimization alternatives, uses public
dialogue to advance waste minimization
efforts, and provides regulatory
incentives for companies to pursue
waste minimization solutions. This
approach will achieve many of the same
ends more efficiently than a detailed
and prescriptive mandatory waste
minimization planning requirement.
D. Comments Requested on Additional
Waste Minimization Incentives
EPA is requesting comment on a three
regulatory incentives that are intended
to encourage companies to pursue waste
minimization measures to reduce or
eliminate hazardous wastes entering
combustion feed streams.
The first incentive was proposed in
EPA's April 19,1996 MACT proposal,
and is being refined in today's NODA.
EPA requested comments on granting
regulated facilities the opportunity to
request a one year extension to the three
compliance period allowed under the
Clean Air Act in cases where the
additional time is clearly needed to
identify and install waste minimization
measures that would reduce the amount
of hazardous waste combusted as a
means of achieving compliance. In
today's NODA, EPA is requesting
comment on several clarifying factors
that will promote consistency while still
allowing flexibility in decision-making
among the EPA Regions and authorized
States who will make determinations on
whether or not to grant one year
extensions to facilities who apply.
EPA is also requesting comment on
extending the agency's current audit
and penalty policies to allow some
companies to enter into a written
consent agreement or consent orders
(CA/COs) in cases where it is clear that
longer than four years (i.e., longer than
a one year extension) is needed to
identify and install waste minimization
measures that significantly reduce
hazardous wastes entering combustion
feed streams. These two approaches are
discussed more below.
40 CFR 63.6(i) describes the authority,
procedures and requirements for
requesting a one year compliance
extension for meeting MACT standards.
Requests must include certain
information, including: A description of
the pollution control, process changes
or process equipment to be installed, a
compliance schedule that describes the
dates by which these controls, process
changes and process equipment, will be
initiated, the dates by which installation
will be completed, and the date by
which compliance will be achieved.
Today, EPA is requesting comment on
language that clarifies the term "process
changes" in 40 CFR 63.6(1) (6) (i)(B)
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
24247
solely with respect to hazardous waste
burning incinerators, LWAKs and
cement kilns, to make it clear that waste
minimization measures are included in
the meaning of process changes for
meeting MACT standards.
By making this clarification, EPA
hopes to encourage the use of waste
minimization measures to reduce the
amount of hazardous waste entering
combustion feed streams as an
. alternative to or supplement to end-of-
pipe emission controls. With respect to
hazardous waste burning incinerators,
LWAKs and cement kilns, EPA includes
in the definition of "process changes"
the following activities: equipment or
technology modifications, reformulation
or redesign of products, substitution of
rawinaterials, improvements in work
practices, maintenance, inventory
control, and environmentally sound '
recycling measures which reduce the
amount and/or toxicity of hazardous
waste entering feed streams of
combustion devices. The term
environmentally sound recycling
includes on-site (including closed-loop
recycling) and off-site recycling
activities that use, reuse or reclaim
hazardous materials in accordance with
EPA regulations. Burning for energy
recovery is not included in the meaning
of "process change" as a basis for
requesting a one year extension for
waste minimization purposes. This
proposed definition would apply only
to hazardous waste burning
incinerators, LWAKs and cement kilns.
The Administrator or a State that has
an approved part 70 permit program (or
has been delegated the authority to
implement and enforce the emission
standard for that source) may grant
extensions under 40 CFR 63.6(i)(9).
Under this approach, decisions to grant
one year extensions will be made by
EPA Regional offices and approved or
delegated state programs. EPA
recognizes that States employ a variety
of approaches for requiring or
encouraging the consideration of waste
minimization measures in achieving
compliance with regulatory
requirements. It is not appropriate for
EPA to supersede State approaches with
a uniform set of criteria for evaluating
waste minimization requests for one
year compliance extensions: However,
EPA believes it is appropriate to
encourage (but not mandate)
consistency' in how these decisions are
made. Therefore, EPA is requesting
comment on a proposal to include four
factors that must, at a minimum be
considered by EPA Regional offices and
approved or delegated state programs in
approving or denying requests for one
year compliance extensions for
hazardous waste burning incinerators,
LWAKs, and cement kilns). These
factors include: •'-'.
• The extent to which the process
changes (including waste minimization
measures) proposed as a basis for the
extension reduce or eliminate hazardous
wastes entering combustion feed
streams and are technologically and
economically feasible.
• Whether the magnitude of the
reductions in hazardous wastes entering
combustion feed streams through
process changes are significant enough
to warrant granting an extension.
• A clear demonstration that
reductions of hazardous wastes entering
combustion feed streams are not shifted
as increases in pollutants emitted
through other regulated media.
• A demonstration that the design
and installation of process changes,
which include waste minimization
measures, and other measures that are
necessary for compliance cannot
otherwise be installed within the three
year compliance period.
These factors will provide a degree of
consistency, while still allowing
flexibility among EPA Regional offices'**
and approved States, in the use of this
innovative regulatory approach. EPA
will also provide separate guidance that
provides examples of how to apply the
factors to consider and additional
information that will be helpful to
government and regulated entities. For
example, the guidance will provide
examples that will help gauge whether
the magnitude of proposed requests to
reduce hazardous wastes entering
combustion feed streams through
process changes are significant enough
to warrant granting an extension. For
example, .companies that commit to a
25% or greater reduction in hazardous
wastes entering combustion feed
streams may be more likely to be
considered for an extension than
companies that commits to only a five
percent reduction.
EPA anticipates that the guidance will
contain other examples on how to
evaluate cases where a low percentage
reduction may actually reflects a
significant improvement relative to
previous significant waste minimization
achievements. The guidance will
address how to evaluate shifts from
combustion feed streams to other
regulated media, such as wastewater
effluents or other pollutant sources. EPA
anticipates the guidance will address
assuring that the proposed process
changes that include waste
minimization measures are critical path
steps toward compliance, and not
process improvements that have little to
do with reductions of hazardous waste
feed streams, and could otherwise have
little impact on compliance. Waste
minimization measures that are not on
a critical path toward compliance or
that do not have a direct impact on
reducing or eliminating hazardous
waste streams entering combustion feed
streams are not good candidates for a
one year extension. Finally, EPA
anticipates the guidance will include a
list of states that have approved part 70
permit programs, a list of states (hat
operate waste minimization technical
assistance programs, and a list of States
that have mandatory or voluntary waste
minimization planning programs.
EPA also points out that companies
that choose to apply for a one year
extension for waste minimization
purposes may wish to coordinate the
development of compliance extension
applications with the development of
"public regulatory notifications of intent
to comply," contained in today's rule,
since much of the developmental work
for the two actions should be nearly
identical.
" In the comments received, several
companies and states said that, in some
cases, even the three year compliance
period plus a one year extension would
not be adequate time to design, and
install waste minimization measures or
additional combustion or treatment
measures necessary to ensure
compliance with the MACT standards.
It may be appropriate, under the
circumstances described below, to grant
facilities who demonstrate that longer
than three years plus a one year
extension is necessary to implement
waste minimization measures that
significantly reduce the amount and/or
toxicity of hazardous waste entering
combustion feed streams additional
time (i.e., longer than four years).
Reducing die amount of hazardous
waste entering combustion feed streams
provides greater long-term levels of
protection for public health and the
environment than other non-waste
minimization/pollution prevention
measures that could be used to comply
with the MACT standard. Since
facilities that need longer than three
years or the three year date plus a one
year extension to meet compliance are
technically in violation (not including
facilities that are granted a one year
compliance extension and meet
compliance within the one year
extension period), EPA will require
these facilities to enter into written
consent agreements/consent orders (CA/
COs) to receive this additional time. The
process changes that include waste
minimization measures must clearly
demonstrate the facility will achieve
significant reductions in the amount of
-------
24248
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1§97 / Proposed Rules
hazardous wastes entering combustion
waste streams over what would have
otherwise have been combusted over the
long term using combustion-based
compliance alternatives installed within
the three year compliance period (or
three years plus a one year compliance
extension). EPA encourages facilities to
consider undertaking longer-term waste
minimization compliance approaches,
subject to limitations proposed today.
EPA will consider such requests using
Its enforcement discretion and the
principles articulated In the Agency's
"Policy on Encouraging Self-Policing
and Voluntary Correction" (60 FR
66706, December 22.1995) (i.e.. the
"Audit Policy"). Within this context,
EPA may, in certain cases, consider a
reduction of penalties for facilities that
are able to install compliance solutions
that demonstrate significant reductions
in hazardous wastes entering
combustion feed streams, but need
additional time beyond dial allowable
under die regulations.
To qualify for tills special
consideration for additional time, a
regulated entity would have to submit a
written request diat contains die
Information listed below. Facilities must
submit requests to the EPA Regional
Office that has oversight for their facility
within one year after die MACT
standards for this rulemaklng are
promulgated. The request would
include:
• An explanation of why die facility
cannot reasonably implement dieir
proposed process changes that include
waste minimization measures wldiin
four years from die date of die
promulgation of die MACT standards.
• An explanation of how die facility's
proposed process changes (that include
waste minimization measures) will
achieve greater reductions in quantity
and/or toxlclty of hazardous wastes
entering combustion feed streams. The
proposed reductions must be
significant EPA will make diese
determinations on a case-by-case basis.
• An explanation of how the waste
minimization/pollution prevention
measures are necessary to achieve
compliance wltii die MACT standards
(i.e., waste minimization measures
which reduce hazardous wastes entering
combustion feedstreams must be shown
to have a direct impact on die
subsequent design, installation and
testing of combustion or odier treatment
measures necessary to achieve and go
beyond compliance standards), and a
schedule for Implementation of the
proposal.
• A waste minimization facility plan.
This plan must follow EPA's "Pollution
Prevention Facility Planning Guide"
(May, 1992; NTIS #PB92-213206), or, if
die facility is located in a State that .
requires mandatory waste minimization
planning, the form of waste
minimization planning required by that
State.
Regulated entities must demonstrate a
clear intent to achieve compliance in a
timely fashion by entering into a
consent agreement/compliance order <•
widi EPA as soon as they exceed die
allotted time provided by the
regulations (including any regulatory
extension). EPA would then exercise its
enforcement discretion to treat a
facility's failure to achieve compliance
by die regulatory deadline as a violation
that can receive penalty mitigation
under die Agency's Audit Policy. Under
the Audit Policy the Agency may give
up to a 100% reduction in the gravity
based component of potential penalties.
To qualify for eliminating the gravity-
based penalty a facility will have to
show that it has a compliance
management program that meets the
criteria for due diligence under the
Audit Policy. Otiierwise, die facility
may qualify for a 75% reduction of the '
gravity component of die penalty. EPA
will provide examples of past'cases in -
die supplemental guidance noted earlier
in this section.
EPA realizes that some waste
minimization compliance measures may
be more cost effective than combustion
based approaches. EPA will retain its
discretion to recover any economic
benefit gained as a result of.
noncompliance. This will ensure that,
facilities that delay compliance for a
specific period of time do not receive an
economic benefit during die period of
non-compliance over regulated entities
that do comply within the regulatory
deadline. For example, EPA may
recover the economic benefit a company
receives by delaying capital
expenditures for modifying their
manufacturing process to meet the new
compliance standards. EPA may
exercise its discretion in appropriate *•
• circumstances to choose the lower ".
figure between: (1) the company's .
pollution prevention/waste
minimization expenditures, and (2)
expenditures the company would have
incurred implementing otiier methods
to come into compliance, when
calculating economic benefit during die
period of non-compliance with the new
regulatory standards. EPA will also use
its enforcement discretion to waive
recovery of insignificant amounts of any
economic benefit resulting from a
facility's delayed compliance.
EPA is also encouraging companies to
pursue waste minimization measures in
an expansion of die provision in die
Clean Air Act regulations that requires
facilities to submit an early notification
that they intend to comply with die
MACT standards as tiiey become
effective (usually about 2-3 years after
die notification is submitted). The
expansion, called a public regulatory
notifications of intent to comply, would
require facilities to include substantially
more detail in this notification on: (1)
' What diey have considered doing to
meet the MACT standards (particularly
widi respect to waste minimization);
and (2) how they have decided to
proceed. This expanded notification
would be sent not only to the regulatory
agency, but would also be made
available to the local community. In
addition, the facility would be required
to hold an informal meeting with the
local citizenry to discuss die
notification. However, regulatory agency
review and approval of the notification
is neither mandated nor expected. This
approach would harness die power of
public opinion to urge facilities to
consider waste minimization
alternatives to end-of-pipe ways of
meeting die MACT standards. This
approach is described in detail
elsewhere in today's NODA for public
comment.
EPA requests comment on die extent
to which die proposed one year
compliance extension, the proposed
opportunity for companies to enter into
consent agreements/consent orders for
periods that extend beyond four years,
and die PRNIC approach provide
companies with appropriate incentives
to pursue waste minimization measures
to achieve compliance.
VI. Permit Requirements
A. Coordination of RCRA and CAA
Permitting Processes
In die NPRM, EPA proposed to place
the final MACT standards in 40 CFR
Part 63 and reference those standards in
40 CFR Parts 264 and 266 (61 FR at
17451). Under this proposal die
standards would only be written out in
die CAA regulations/but tiiey would
legally be part of both the CAA and
RCRA regulations. Thus, bodi programs
would have an obligation to address die
standards in permits issued under their
authority. EPA proposed this approach
to provide die maximum amount of
flexibility for state permitting
audiorities to coordinate die issuance of
permits and enforcement activities in a
way which most effectively addresses
their particular situation.
After reviewing die NPRM comments,
diere is some question on whether the
proposed approach will provide die
maximum amount of flexibility to the
-------
Federal Register / Vol. 62, No. 85 /Friday, May 2, 1997 / Proposed Rules
24249
state permitting authorities. The
proposed approach would still require
in most cases at least two different
permitting authorities to review the air
emission standards in a permit Since
under the original proposal the
, standards would be in both the RCRA
and CAA regulations, permit writers
from each program might be required to
address them to some degree in a permit
under that program, either by writing
. them directly in the permit or by
referencing them from the other permit
The proposed approach might not have
given states the flexibility to implement
the new standards under a single
regulatory program. Thus, die proposed
approach would result in dupficative
permitting actions in many cases.
Commenters had several other
concerns with an approach where the
air emission standards are incorporated
into two permits. One major problem
described by commenters is that the
overlapping permit conditions of the
Title V and RCRA permits would be
subject to two separate permit.
modification procedures, administrative
appeals procedures, and potentially
separate judicial procedures as well.
The Agency now believes that this
outcome could be needlessly
duplicative and unwieldy, and therefore
not consistent with the Agency's intent
to simplify permitting.
Additionally, commenters were
concerned that the proposed approach
would have allowed for dual
enforcement scenarios where
enforcement actions under both statutes
would be brought against the facility for
a single violation. In the NPRM, EPA
stated that the Agency did not expect to
enforce under both permits (61 FR at
17452). However, commenters noted
that this statement did not restrain the
states from initiating dual enforcement
. actions, or citizens from initiating dual
citizen suits.
Codifying the MACT standards in
only one place in the regulations (unlike
the proposed scheme) may actually
provide states the greatest flexibility in
the way they issue permits and prevent
duplication of effort Although die
standards would be codified under one
statute, states could decide which
program they want implementing the
standards. A state would be free to
decide, for example, to have its RCRA
staff implement a set of CAA standards.
Another approach would be for a state
to decide under which state statute to
adopt the MACT standards based on
which part of their, program they wish
to implement the standards. For
example if EPA places the MACT
standards in part 63 only (see below), a
state could still decide to adopt those
standards under their state solid waste
statute and implement the standards
through their RCRA hazardous waste
program, depending on how their state
solid waste statute is written. The basic
premise in this approach is that it is not
significant to EPA, nor to proper
implementation of RCRA or CAA, under
what statute a state adopts a RCRA or
CAA regulation.
EPA particularly would like to take
comment on this issue. Do states believe
they can decide under which program to
implement the MACT standards if they
are only placed in Part 63? EPA is
concerned that states be allowed to
implement the standards through either
their CAA or their RCRA program, t*
whichever works best for their
particular situation.
Currently, EPA is considering placing
die MACT standards only in 40 CFR
part 63 and relying on die air program
implementation scheme, including die
Title V permitting program, to bring
facilities into compliance with die new
standards. This approach (as opposed to
die converse—placing the standards
only in the RCRA regulations) is die
only approach that appears feasible to
allow the standards to be codified in
only one place in die regulations. The
Agency would rely on the integration
provision of RCRA section 10Q6(b)(l) to
defer RCRA controls on these air
emissions to die part 63 MACT
standards. CThe CAA does not have a
similar integration provision which
would allow deferral of CAA
requirements to RCRA regulations.)
We emphasize, however, diat under
diis approach, tiiere would still be a
need for a RCRA permit at H WC
facilities, to address any other RCRA
units on site, and to address RCRA
regulations which apply to all types of
RCRA facilities and which are not
duplicated under CAA. For example, a
permit will be required to address
hazardous waste storage units that hold
die waste prior to combustion. As with
all RCRA permits, the permit would
require compliance with die standards
in 40 CFR part 264 (including general
facility standards, preparedness and
prevention requirements, contingency
planning and emergency procedure
requirements, manifesting requirements,
recordkeeping and reporting
requirements, releases from solid waste
management units requirements, closure
and post-closure requirements, financial
requirements, corrective action
requirements, storage requirements,
materials handling requirements, and
air emissions standards for process
vents, equipment leaks, tanks, and
containers). The omnibus provision of
RCRA Section 3005 (c) (3), codified at
§270.32(b)(2), which provides for
additional permit conditions as
necessary at a particular site to protect
human healdi and die environment,
would also need to be addressed in the
RCRA permit, widi respect to die
combustor and other activities at die
facility. (This issue is discussed further
in die next section.) Among' other
consequences, diis means that die
current program of processing RCRA
HWC permits will continue until EPA
finalizes any program changes. It
remains a.high priority to bring all HWC
under full Part B permits as soon as
possible.
Aldiough die RCRA permit would not
need to duplicate die MACT controls
contained in a Title V permit, there will
typically be a number of waste
management activities associated with
die combustion unit that would need to
be addressed in die RCRA permit (and
not die Title V permit), such as
materials handling (feed and residues)
and combustor-specific (but not MACT-
related) waste analysis requirements
and feed restrictions. If, as under die
original proposal, die Agency decides to
retain the DRE standard in die RCRA
regulations, then DRE would also need
to be addressed in the RCRA permit.
The discussion above describes one
approach die Agency is considering for
die final rule. If diis approach were
adopted, it would establish how EPA
would implement die new MACT
standards where the Agency has -
permitting jurisdiction. However, in
many cases, states are delegated RCRA
and CAA authority. It would dierefore
be up to die state program to decide
how best to implement die MACT
standards given die particular
audiorities of the state. The approach
described today may be better suited to
provide greater flexibility for state
approaches, whether die State prefers to
.rely primarily on die MACT and Title V
permit process or die RCRA permit
process to impose the new standards.
The Agency recognizes that in many
cases facilities will already have a RCRA
permit in place.when die MACT
standards become effective. This
situation raises die question of what
happens to RCRA permit conditions
related to combustor air emissions.
From an overall standpoint it is
expected that die MACT standards will.
be more stringent than many current
RCRA regulations and permit
conditions. However, at some
individual sites, certain RCRA permit
conditions may be more stringent than
die corresponding MACT emissions
. standards. Some potential reasons why
such a situation would o'ccur are •
because die RCRA permit condition is
-------
24250
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
based on a site-specific risk evaluation
under the BIF rule or the omnibus
provision; because the MACT standard
is in a different format than the permit
condition (e.g., a mass emission rate or
removal efficiency format in a RCRA
permit vs. a concentration-based
standard for HC1 under MACT) and at
that particular site the RCRA. format-
yields more stringent control; because,
in the case of CO limits in early
incinerator permits, the RCRA permit
limit was based on levels during the
trial bum; or because the facility was
one of the lower emitters, in the
standards development MACT pool.
The Agency's overall intent is for the
MACT standards to replace the RCRA
air emissions standards for hazardous
waste combustors. Therefore, where the
Agency has permitting jurisdiction, the
RCRA air emissions permit limits for
HWCs, with the exception of site- '
specific risk-based limits, would be
deleted from RCRA permits when the
MACT standards become operational. In
the case of site-specific risk-based
limits, based either on the BIF metals
and HC1/C12 requirements or omnibus
authority, these limits would remain in
RCRA permits to satisfy the
protectiveness requirement of RCRA
section 3004 (a) and (q). As with EPA
Issued permits, in authorized states any
site-specific risk-based limits would
need to be retained where necessary to
satisfy RCRA protectiveness
requirements. Since authorized states'
are allowed to be more stringent, states
will determine, in the process of
deciding whether to delete old RCRA-
based regulations and in the permitting
process, whether to keep or delete more
stringent permit conditions which are
not based on a site-specific risk finding.
EPA would like to take comment on
the approach of placing the MACT
standards only in the .part 63
regulations, and deferring the RCRA
standards, as described above.
B. Permit Process Issues
As discussed above, the Agency is
considering an approach of placing the
MACT standards only in 40 CFR part 63
and using RCRA 1006(b) authority to
defer RCRA permitting to the Title V
permitting program for the air emission
standards only. This approach raises the
issues of how and when the permitting
authorities should modify existing
RCRA permits to remove the air
emission standards. The Agency's
current thinking is that the RCRA
permit should continue to apply until a
facility completes its comprehensive
performance testing and its Title V •
permit Is issued (or its existing Title V
permit Is modified to include the MACT
standards). The RCRA permit would
then be modified to remove the air
emission limitations which are covered
in the Title V permit. Another option is»
to modify the RCRA permit at the time
the facility submits their comprehensive
performance test results. However, it is
beneficial to wait until the test results
are reviewed, approved, and written
into a Title V permit before deleting any
RCRA permit conditions because of the
greater level of Agency and public
review that occurs during-the permit
process. The Agency would like to take
comment on this issue. At what point
should the RCRA permit be modified to
remove air emission standards? How
should the switch-over to the new
permitting system occur? Note that
irrespective of when the Title V permit
is issued/modified, the MACT standards
and associated operating limits become
enforceable according to the schedule in
the final rule.
After the compliance date for the final
rule, but before the RCRA permit is
modified to remove any air emission .
limitations, there will be a period where
a facility will have both a RCRA permit
that addresses air emissions and either:
(1) A precertification of compliance
document with applicable operating
conditions that they have submitted; or
(2) a Title V permit which also
addresses air emissions. Note, the RCRA
permit will continue to apply until such
time that it is modified'to remove any^
air emission limitations. The
precertification of compliance
document or Title V permit will not
automatically supersede RCRA permit
conditions as a matter of law. The more
stringent conditions will govern.
C. Omnibus and RCRA/CAA Testing
Coordination
As discussed in the preamble to the
proposed rule (61 FRat 17371), EPA
currently has a national RCRA policy of
strongly recommending to all federal
and state RCRA permit writers that,
under the omnibus provision of RCRA
section 3005(c)(3), site-specific risk
assessments (SSRAs) generally be
performed as part of the RCRA* -.
permitting process to determine
whether additional conditions are
necessary to .protect human health and
the environment The results of these
risk assessments are then used to set
protective permit conditions. Under the
new permitting scheme that the Agency
is considering (placing the MACT
standards only in 40 CFR part 63), the
Agency is considering when the RCRA
omnibus provision would continue to
be used—for example, to require a site-
specific risk assessment—and the timing
. of the RCRA omnibus finding in relation
to the Title V permit issuance/
modification.
As discussed in the NPRM, the
Agency has indicated a preference for
modifying our current policy of
recommending that a site-specific risk
assessment (SSRA) be performed during
permitting at hazardous waste
combustors in most cases (61 FR at
17372). Depending on the scope and
level of the final MACT standards, this
policy may need to be re-evaluated. For
at least some facilities, there might still
be sufficient cause to perform a SSRA
under the RCRA omnibus permitting
authority.
Thus, the Agency is also considering
the timing issue of whether a RCRA
omnibus finding would be expected to
occur at the same time as the Title V
permitting decision (or the Title V
permitting modification decision, if this
is more appropriate, since some of these
units will most likely already have Title .
V permits). The Agency expects that
many of the trial burns to support
SSRAs will already be completed prior
to the effective date of the MACT rule,
and would not need to be repeated
provided none of the resulting
emissions limitations are relaxed based
on the MACT rule. For facilities where
trial burns for risk assessments have not
been performed, a RCRA omnibus
determination as to whether a SSRA is
needed can be made in most cases
before the comprehensive test protocol
is finalized. This situation would allow
the MACT comprehensive test protocol
and RCRA trial burn plan to be
coordinated with respect to sampling
and analysis procedures and operational
protocols. However, the Agency does
not plan to hold up comprehensive
performance test approval or the Title V
permit process (modified or new
permits) to accommodate a RCRA
omnibus finding. -
If it were not possible to make the
RCRA omnibus determination in
sufficient time to allow coordinated
emissions testing, then a separate RCRA
trial burn might be necessary. This
separate test event would increase the
costs to the facility and require more
oversight by the permitting authority.
After allowing for additional time to
perform a SSRA, the findings of the risk
assessment could then be used to
establish site-specific standards which,
in turn, might require a review of the
Title V permit and its associated
operating limits/standards.
It should also be noted that if the DRE
standard is retained under RCRA (see
discussion in Section HI.A.), these same
testing coordination issues apply to DRE
testing. (At sites where SSRAs are to be
performed, it is expected that DRE
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
24251
testing and testing necessary to provide
data for SSRAs will be occurring at the
same time.) ,
We invite comment on the
workability of this approach for
achieving maximal coordination of the
RCRA trial burns and omnibus findings
with the initial MACT comprehensive
test and Title V permitting.
Part Four: Miscellaneous Issues
/. 5000 Btu per Pound Policy for Kiln
Products
Current Agency policy exempts
cement product (clinker) from cement
kilns burning hazardous waste from
regulation as a hazardous waste
provided the fuel value of the hazardous
waste exceeds 5000 Btu per pound 6S.
This allows cement kilns to burn high-
Btu hazardous waste for energy recovery
purposes and still market the clinker
and the cement mix produced from the
clinker as commercial product free from
any Subtitle C concerns. The Agency
has already provided a clarification (53
FR 31198, August 17, 1988) that the
regulations for "waste derived
products" at § 266.20 do not apply to
products from processes using
hazardous waste (HW) fuels, unless
these processes also use hazardous
wastes as "ingredients" in a product
destined for land application (i.e., the
product must "contain" the HW as an
ingredient to be covered by § 266.20) or
burn hazardous waste for destruction.
To implement this regulation, the
Agency has used Btu values of a waste
as a proxy to. determine whether
contaminants in the HW fuels will or
will not be deemed to transfer to the
product (i.e., become ingredients). Over
time, many commenters have submitted
data and have suggested that the heat
content of a waste is an indirect and
imprecise way of identifying whether
materials should be subject to the
provisions of § 266.20 (hazardous
wastes used in a manner constituting
disposal).
"The Agency has been interested for
some time in considering whether and
how to change the existing Btu
approach. For example, 60 ER 7376
(February 7,1995) discusses a possible
exclusion of clinker from the derived-
from rule, even when cement kiln dust
68 Wastes with energy value greater than 5000 Btu
may generally be said to be burned for energy
recovery, since this is the Btu value of low grade
fuels. 48 FR 11157-59 (March 16.1983).'However,
lower energy wastes could conceivably be burned
for energy recovery in industrial furnaces, such as
cement kilns, or in industrial boilers due to these
devices' general efficiency of combustion. Id. At
11158. Thus, the 5000 Btu level is not an absolute
measure of burning for energy recovery (i.e., a rule),
particularly when industrial furnaces and industrial
boilers are involved.
is introduced in the feed. EPA has also
discussed with CKRC the narrower issue
of whether the 5000 Bui/IB energy value
level reliably predicts whether toxic
contaminants would more likely
partition to the clinker and ultimately
the cement product Some from industry
have suggested that a facility that agrees
to limit waste feed metals to their
"historic average" could be exempted
from the 5000 Btu/hr policy. The
rationale is that even if the facility took
lower Btu.waste, they would not be
taking higher quantities of metal waste
than currently, at least on the average.
This would address EPA's concern
about allowing an increase of metals in
HW fuels burned by cement kilns if the
5000 Btu restriction were abandoned.
Today, without our endorsement at '*
this time, the Agency is offering this
concept and some potential variations
•for public comment The Agency is
interested in the possible ramifications
and requests comment, particularly with
respect to limiting the concentrations of
metals in cement products from cement
kilns burning hazardous waste. To take
advantage of such a policy, a facility
would have to establish a baseline of
metals feed in .the hazardous waste (for
example, the average of the previous .
three years) and then agree to
enforceable permit conditions limiting
metals feedrate levels to that average
plus one standard deviation.'
Presumably, enforceable restrictions on
metal feed rates should control metal
partitioning to clinker and CKD much
more effectively than would the Btu
limit and ensure that these materials
would not contain an increase in toxic
metal constituents from the hazardous
waste used ,as fuel. Also, metal feed +
limits based on a historical average
would appear to be more stringent than
the current BIF metal feed limits, which*
are set on a health basis considering
direct inhalation of metals emissions.
(In other words, as discussed in earlier
sections of this notice, cement kilns are
generally feeding metals far below
allowable BIF limits.)
EPA seeks comment on allowing
cement kilns (and LWAKs) the option of
complying with the following, which is
only partly based on the suggestions
discussed with cement kiln
representatives, with some additions:
• An owner or operator of a cement
kiln burning hazardous waste would be
allowed to burn hazardous waste with
any Btu content, provided the owner or
operator agrees to enforceable hazardous
waste feed operating limits on metals of
concern (see below);
• These metals feed limits would be
set at levels that would ensure, at least
on an annual basis, that metals on a
mass basis do not increase over current
levels, which ark substantially less than
those allowable under BIF (and sources
would, of course, remain subject to
stack emission standards to control the
emission of metal HAPs);
• Feed limits would have to be
established for each of the following
twelve metals: antimony, arsenic,
barium, beryllium.'cadmium,
chromium, cobalt, lead, nickel,
selenium, thallium, and vanadium;
• Sampling and analysis would be
conducted as often as necessary to
document that the metals levels are .
below the limits and included in the
facility's waste analysis plan required
by 40 CFR 264.13; and
• Results of the analysis would have
to be available for public inspection.
Also, the Agency is considering a
variation of this option, under which
kiln operators would have to achieve
specified percentage reductions of the
total quantity (on an aggregate basis) of
the following metals in their wastes •
combusted: antimony, arsenic, barium,
beryllium, cadmium, chromium, cobalt,
lead, nickel, selenium, thallium, and
vanadium. EPA chose these particular
metals based on their potentially high
human health and ecological risk in
conjunction with their significant
tendencies to persist in the environment
and accumulate in living tissue. If
generators reduce metals in wastes over
time, holding kilns to the average of the
past three years may actually allow
increased burning of certain metal-
bearing streams. This is because other
streams may contain less metals. In
contrast, commitments to reducing
metals below baseline limits would
ensure that progress continues in waste
minimization. EPA requests comments
on this option, including information
about: (1) The prevalence and
distribution throughout industry sectors
of waste streams bearing these metals
sent to combustion, and (2)
opportunities for generators to reduce
these metals in wastes sent to
combustion by means of source
reduction during generation.
EPA requests comment on the impact
of imposing limits on metals
concentration on waste streams
combusted in cement kilns. EPA raises
these questions:
• How much hazardous waste now
sent to cement kilns for energy recovery
would be likely to meet such metal level
limitations?
« Of the fraction of wastes that would
"fail" a metals limit, would generators
of waste now sent to cement kilns
reduce metals concentrations in these
wastes, using waste minimization and
pollution prevention, so that cement
-------
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
24253
that might result from physical
processing. Given that a sand appears
Integral to foundry operations and TRUs
can greatly Improve the efficiency of
sand use, EPA could conclude that even
without any rule changes, foundry
operators may be eligible for a variance
from the RCRA definition of solid waste
under the variance provisions found at
40 CFR 260.30(b), 260.31(b), and 260.33.
Under these variance provisions, EPA
(or an authorized State) may grant a
variance from the definition of solid
waste for materials that are.reclaimed
and then used as feedstock within the
original production process in which
the materials were generated if the
reclamation process is an essential part
of the production process. This
evaluation is guided by a number of
criteria found at § 260.31 (b). While
foundries certainly can and do operate -
without thermally processing their
sands, and so TRUs are not literally
"essential", as summarized above the
units do in fact greatly increase
efficiency of sand use, which is an
essential raw material of foundry
operations. Also, the TRUs are
physically proximate, and integrated
into the foundry's operations. Emissions
from the TRUs are often ducted into
emission control devices used for the
foundries' main production activities.
As such, the Agency could view sands
being processed In TRUs as potentially
eligible for the variance under
260.31 (b) ™. EPA (or the State) would
70 The Agency notes that, typically, a variance
from the definition of solid waste under 260.31 (b)
•would apply at the point of generation (e.g., in this
case, the point where the spent sands are removed
from the casting forms). Also, typically, when such
a variance is granted, the variance is only
applicable to those secondary materials that meet
the conditions of the variance (e.g., the variance
would not include secondary materials that are not
reused in the production process).
The normal and efficient flow of materials at
faculties with a TRU may involve the processing of
all of the spentsand generated. However, after
recovery of the sand, insubstantial amounts of
: sands that are processed by the TRU may be found
to be unusable again as foundry sand, and so may
be discarded. While treatment and disposal of the
spent foundry sand is clearly not the intent of the
TRU, "treatment and disposal" would be the
regulatory status of any hazardous secondary
material that is processed such that it is no longer
hazardous and then discarded, given the most
straightforward reading of die regulations.
Nevertheless, the Agency believes that because
the TRU is typically integrated into the facility's
operation*, and the flow of spent foundry sand into
the TRU becomes a standard operating procedure,
the incidental discard of an insubstantial amount of
spent foundry sand should not overshadow the
baste purpose of § 260.31 (b) to grant a variance from
the definition of solid waste to materials that are
reclaimed and reused in the production process,
where such reclamation is, in effect, an integral step
in the Cow of production. Thus, the Agency asserts
that, assuming all other conditions of the
S 260.31 (b) variance are met, the fact that a
relatively Insignificant amount of spent foundry
still have to weigh the factors in
paragraph (b) on a case-by-case basis to
determine if the variance should be
granted. For example, paragraph (b) (3)'
requires an examination of how the
sands are handled to ensure that losses
are minimized before reclamation. Also,
paragraph (b)(8) allows consideration of
"other factors" as appropriate, and in
this case, air emissions controls for the
TRU would be appropriately considered
before granting a variance. As discussed
above, controls may be installed as paijp
of the MACT process, or simply due to *
state or local air pollution laws. The
Agency would expect that as a
minimum, emissions of paniculate
matter would have to be limited to
control lead emissions, and given the
organic binder compounds being
introduced to the units, limits on and
continuous monitoring of indicators of
efficient combustion, such as CO and/or
HC, would seem appropriate. Under this
approach, the Agency might or might
not develop special standards for TRUs •
under RCRA or the CAA. The case-by-
case approach might enable EPA and
the States to oversee the units without
the need for federal standards.
III. -Status of Caseous Fuels Generated
From Hazardous Waste Management
Activities
The proposed rule included a
proposed exclusion from subtitle C
jurisdiction for certain synthetic gas
fuels derived from hazardous waste
treatment activities (61 FR at 17465).
Some commenters stated that synthesis
gas fuels are beyond EPA's regulatory
authority because they are uncontained
gases, and further stated that EPA had rf
failed to set out any explanation for its
potential-jurisdiction over these
synthesis gas fuels (which jurisdiction
EPA proposed to relinquish provided
the syngas met designated
specifications).
The type of syngas discussed in the
proposal results from thermal reaction
of hazardous wastes, which reaction is
optimized to break organic bonds and
reformulate the organics into hydrogen
gas arid carbon monoxide. Id. This
resulting gas can.be used as a fuel at
manufacturing facilities.
EPA has broad statutory authority to
regulate fuels produced from hazardous
wastes. RCRA section 3004(q)(l): see
also Horsehead Resource Development
Co. v. Browner, 16 F. 3d 1246, 1262
(D.C. Cir. 1994) (broadly construing this
authority). The fact that syngas (by
definition) is a gas, rather than a solid
or liquid,, does not appear to raise
jurisdictional issues. It is still produced
from the hazardous wastes that are
being processed thermally. See
§261.2(c)(2)(A) and (B) (defining such
materials as solid wastes). EPA believes
its authority to be clear under these
provisions, but will consider further
comment on the issue.7.1
TV. Regulatory Flexibility Analysis
The Regulatory Flexibility Act (RFA)
of 1980 requires Federal agencies to
consider impacts on "small entities"
throughout the regulatory process.
Section 603 of the RFA calls for an
initial screening analysis to be
performed to determine whether small
entities will be adversely affected by the
regulation. If affected small entities are
identified, regulatory alternatives must
be considered to mitigate the potential
impacts. Small entities, as described in
the Act, are only those "businesses,
organizations and. governmental
jurisdictions subject to regulation."
In preparation of the proposed rule,
EPA used information from Dunn &
Bradstreet, the American .Business
Directory and .other sources to identify
" small businesses. Based on the number
of employees and annual sales
information, EPA identified 13 firms
which may be small entities. That.
analysis also determined that the
proposed rule was unlikely to result in
detrimental impacts to small businesses.
This conclusion was derived from two
important findings:
First, few combustion units are owned
by businesses that meet the SBA
definition. Among those that are •
considered small (based on number of
employees), over one-third were found
to have gross sales in excess of $50
million per year. Furthermore, available
data indicate an ongoing industry trend
toward consolidation, or market exit'
Second, small entities impacted by
the rule, were found to be those that
currently burn very little hazardous
waste, and hence face very high cost per
ton burned. These on-site facilities are
likely to discontinue burning hazardous
waste and dispose off-site, rather than
comply with the proposed rule. Based
on available data, EPA found that the
incremental cost of alternative disposal
associated with discontinued burning of
such waste would not exceed 0.10 to
0.20 percent of annual corporate gross
revenues. Furthermore, currently viable
commercial small business facilities
affected by the proposal were found to
remain profitable. •
sand is discarded would not negate a variance
granted to spent foundry sand, or require a
treatment permit for the TRU.
7i See also 50 FR 49164. 49171 (Nov. 25,1985);
52 FR 16982,17021 (May 6,1987): and 56 FR 7134,
7203-04 (Feb. 21,1991) which discuss this
question, although inconclusively;
-------
24254
Federal Register / Vol. 62, No. 85 / Friday, May 2, 1997 / Proposed Rules
The above findings indicate that the
proposed rule is expected,to have
overall negligible impacts on small
entities. The Agency is currently
refining and expanding its analysis of
small entities and makes no conclusions
beyond those presented for the
Proposal.
Dated: April 22, 1997.
Elizabeth Cotsworth,
Acting Director, Office of Solid Waste.
[FR Doc. 97-11155 Filed 5-1-97; 8:45 am]
BILLING CODE 6560-50-P
-------
------- |