EPA-450/3-82-005b
Revised Standards for Basic
Oxygen Process Furnaces -
Background Information
for Promulgated Standards
Emission Standards and Engineering Division
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air, Noise, and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
December 1985
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This report has been reviewed by the Emission Standards and Engineering Division of the Office of Air Quality Planning.1
and Standards, EPA, and approved for publication. Mention of trade names or commercial products is not intended to consti- f
tute endorsement or recommendation for use. Copies of this report are available through the Library Services Office (MD-35),
U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; or, for a fee, from the National Techni- j
cat Information Services, 5285 Port Royal Road, Springfield, Virginia 22161.
Publication No. EPA-450/3-82-005b
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ENVIRONMENTAL PROTECTION AGENCY
Background Information
Final Environmental Impact Statement
Revised Standards of Performance
for Basic Oxygen Process Furnaces
Prepared by:
Jack R. Farmer
Director, Emission Standards and Engineering Division
U. S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
TDate)
The promulgated standards of performance would limit secondary
emissions of particulate matter from new, modified, and reconstructed
basic oxygen process steelmaking facilities. The final standards
implement Section 111 of the Clean Air Act (42 U.S.C. 7411) and are
based on the Administrator's determination that the previously
promulgated standards for BOPF's no longer reflect application of the
best demonstrated technology (BDT) for these facilities.
Copies of this document have been sent to the following Federal
Departments: Office of Management and Budget; Labor, Health and Human
Services, Defense, Transportation, Agriculture, Commerce, Interior, and
Energy; the National Science Foundation; the Council on Environmental
Quality; members of the State and Territorial Air Pollution Control
Adminstrators; the Association of Local Air Pollution Control
Officials; EPA Regional Administrators; and other interested parties.
For additional information contact:
Mr. Doug Bell :
Standards Development Branch (MD-13)
U. S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
Telephone: (919) 541-5578
Copies of this document may be obtained from:
U. S. EPA Library (MD-35)
Research Triangle Park, North Carolina 27711
National Technical Information Service
5285 Port Royal Road
Springfield, Virginia 22161
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TABLE OF CONTENTS
Section Page
1.0 SUMMARY 1-1
1.1 Summary of Changes Since Proposal 1-1
1.1.1 Subpart Na Rules . . ., 1-1
1.1.2 Subpart N Amendments 1-5
1.2 Summary of Impacts of Promulgated Action 1-10
1.2.1 Alternatives to Promulgated Action 1-10
1.2.2 Environmental Impacts of Promulgated Action. . 1-10
1.2.3 Energy and Economic Impacts of
Promulgated Action 1-11
1.2.4 Other Considerations 1-11
2.0 ' SUMMARY OF PUBLIC COMMENTS 2-1
2.1 Emission Data 2-1
2.1.1 Particulate Matter Test Reports 2-1
2.1.2 Teemi'ng Emission Factor ' . 2-3
2.2 Affected Facilities
2.2.1 Definition of Affected Facilities 2-3
2.2.2 Definition Clarification 2-6
2.2.3 Selection of Affected Facilities . 2-7
2.2.4 Teeming and Hot Metal Desulfurization 2-10
2.3 Best Demonstrated Technology
2.3.1 Demonstration of Operating Practices 2-12
2.3.2 Roof-mounted Electrostatic Precipitators . . . 2-13
2.3.3 Fume Suppression 2-14
2.3.4 Capture Efficiency of Auxiliary
Hooding for Bottom-Blown Furnaces 2-17
2.3.5 Capture Efficiency of Building Evacuation
Systems 2-18
2.4 Numerical Emission Limits ........ 2-18
2.4.1 Mass Standard for Secondary Emission
Collection Devices 2-18
2.4.2 Closed Hood Furnace Primary Control Device
Emission Limit 2-19
2.4.3 Allowance for Oxygen Blowing During
Bottom-Blown Vessel Turndown 2-20
2.4.4 Opacity Limit for Bottom-Blown Furnaces. . . . 2-21
IV.
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Table of Contents (concluded)
Section Page
2.5 Visible Emission Standards. ............. 2-22
2.5.1 Reference Method 9 2-22
2.5.2 Three-Minute Average 2-27
2.5.3 Alternative Mass Emission Limits 2-33
2.5.4 Ancilliary Operations 2-34
2.6 Emission Testing and Monitoring
2.6.1 Revised Test Time for Primary Emissions. . . . 2-35-
2.6.2 Revised Steel Production Cycle 2-36
2.6.3 Secondary Emissions Performance Test 2-37
2.6.4 Secondary Control Device Monitoring 2-38
2.6.5 Process Monitoring 2-39
2.6.6 Secondary Emission Steel Production
Cycle . 2-40
2.7 Equipment, Design, and Operating Specifications . . . 2-41
2.7.1 Operating Practices. 2-41
217.2 Pperating Specifications 2-43
2.7.3 Consideration of Baghouse Pressure Drop
Monitoring • • 2-44
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LIST OF TABLES
Title
2-1 List of Commenters on Proposed Standards
2-2
Hot Metal Transfer Flame Suppression Evaluation for the
BOPF New Source Performance Standard (NSPS) Revision . . .
2-3 Observer Error for 3-Minute and 6-Minute Opacity
Averaging
2-4 Standard Deviation of Error (Between-Observer Precision)
for Different Averaging Times (By Location and Smoke
Color) . .
Page
2-2
2-16
2-29
2-32
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1. SUMMARY
On January 20, 1983, the U.S. Environmental Protection Agency
(EPA) proposed standards of performance for basic oxygen process
furnaces (BOPF's) under authority of Section 111 of the Clean Air Act
(48 FR 2658). Public comments were requested on the proposal in the
Federal Register. A total of five sets of public comments were received.
Four commenters were industry representatives; also commenting was one
private environmental engineering firm. The comments that were sub-
mitted, along with responses to these comments, are summarized in this
document. The summary of comments and responses serves as the basis
for revisions made to the standards between proposal and promulgation.
1.1 SUMMARY OF CHANGES SINCE PROPOSAL
The proposed rules for BOPF's were contained in two Subparts of
40 CFR Part 60—-Subparts Na and N. The following two sections describe
the proposed and final rules.
1.1.1 Subpart Na Rules
As proposed, Subpart Na applied to secondary emissions from
top-blown and bottom-blown BOPF's and to hot metal transfer and skimming
stations. Visible emissions from the BOPF shop roof monitor or other
building openings were limited to no more than 10 percent opacity
during the operation of any top-blown BOPF, except that an opacity
greater than 10 percent but less than 20 percent could occur once per
steel production cycle. Visible emissions from the BOPF shop roof
monitor or other building openings were limited to no more than 30 per-
cent opacity during the operation of any bottom-blown BOPF, except
that an opacity greater than 30 percent but less than 60 percent could
occur twice per steel production cycle. Mass emissions of particulate
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matter exiting "a control device were limited to no more than 23 mg/dscm
(0.010 gr/dscf). The opacity of visible emissions exiting the control
device was limited to no more than 5 percent. Compliance with the
proposed visible emission standards was determined by Reference Method 9
through 3-minute averages. Compliance with the proposed mass standard
for the collection device was determined with the use of Reference
Method 5.
A roof-mounted electrostatic precipitator (RMESP) used to control
secondary emissions from an affected facility was exempted from the
mass and opacity standards for secondary emission control devices. A
device used to control both primary and secondary emissions also was
exempted from the secondary emission control device mass and opacity
standards.
A number of changes have been made to Subpart Na since proposal.
The most significant change is in the applicability of the final
standards resulting from the withdrawal of the roof monitor opacity
.standard for bottom-blown BOPF's. The rationale for this change is
discussed in Chapter 2, Section 2.4, entitled "Numerical Emission
Limits."
The final rules apply to secondary emissions of particulate
matter from top-blown BOPF's and hot metal transfer and skimming
stations used with bottom-blown or top-blown BOPF's that have been
constructed, modified, or reconstructed after January 20, 1983.
Visible emissions from shop roof monitors (or other building openings)
may not exhibit more than 10 percent opacity during the steel production
cycle of a top-blown BOPF and during hot metal transfer or skimming
for a bottom-blown BOPF, except that an opacity greater than 10 percent
but less than 20 percent may occur once per steel production cycle.
Visible emissions from the shop roof monitor during the bottom-blown
furnace cycle (i.e., the steel production cycle excluding hot metal
transfer and skimming) are not subject to the roof monitor opacity
standard. Mass emissions from a secondary emission collection device
are limited to 23 mg/dscm (0.010 gr/dscf). Control device opacity is
limited to 5 percent. These emission limits also apply to top-blown
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BOPF's and to hot metal transfer stations or skimming stations used
with a bottom-blown or a top-blown BOPF. Under the final rules, fume
suppression systems are exempt from the mass and opacity limits for
the secondary emission collection device, as is any device used to
control primary and secondary emissions. RMESP's are not exempt from
the final mass and opacity standards for secondary emission collection
devices.
Numerous clarifying changes also have been made to §60.141a,
which includes definitions for terms used in the secondary emission
standards. For example, the definition of "hot metal transfer" was
expanded to include the transfer of molten iron from the torpedo car
to the charging ladle, or from the torpedo car to an intermediate
vessel and from the intermediate vessel to the charging ladle.
Definitions proposed for "primary emissions" and "secondary emissions"
also were expanded and a new definition for "primary emission control
system" was added, as were definitions for new technologies, such as
fume suppression systems. The definition of "startup" was deleted
from the final rule because the General Provisions of 40 CFR Part 60
now include a definition for this term. Additionally, the definition
of "steel production cycle" was expanded to include preheating (when
used) and vessel turnup, as well as vessel turndown, during sampling
operations.
The monitoring requirements for the secondary emission control
system were also modified. As proposed, §60.143a required the use of
a monitoring device that continuously records the various exhaust
ventilation rates through the secondary emission control system for
each phase of each steel production cycle. The final rule specifies
that the owner or operator install, calibrate, operate, and maintain a
monitoring device that continually measures and records for each steel
production cycle the various exhaust ventilation rates or levels of
exhaust ventilation through each duct of the secondary emission control
system for each phase of each steel production cycle. The final
monitoring provisions also include a requirement for the semiannual
reporting of monitoring measurements over any 3-hour period that
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averages more than 10 percent below the average levels maintained
during the most recent performance test for demonstrating compliance
with the mass standard for secondary emission collection devices. A
similar provision also was added to require semiannual reporting if a
scrubber primary emission control device is used for secondary emission
collection. Operating requirements were also added to §60.143a for
the use of strip chart recorders. The rationale for these changes is
discussed in Chapter 2, Section 2.7, entitled "Equipment, Design, and
Operati ng Speci fi cati ons."
Several clarifying changes were made to §60.144a regarding test
methods and procedures. First, §60.144a(b)(l), which provided for the
aggregation of visible emission observations from multiple exit points,
was deleted from the final rule. A new provision was added that
provides instructions for comparing the velocity readings obtained by
Reference Method 2 to the step changes recorded by a device that
monitors the level of exhaust ventilation. The sampling requirements
for secondary emissions by Reference Method. 5 were also modified. The
proposed rule specified that the sampling for each run is to continue
for a sufficient number of steel production cycles to ensure a total
sample volume of at least 2.27 dscm (80 dscf) for each run. The final
rule increases the requirement for total sample volume to 5.67 dscm
(200 dscf). A new provision was also added that allows shorter sampling
times and smaller sample volumes, subject to approval by the Administrator,
when necessitated by process variables or other factors. This revision
is discussed in Chapter 2, Section 2.6, entitled "Emission Testing and
Monitoring."
Many of the compliance provisions proposed under §60.145a were
expanded or clarified. Sections 60.145a(a) and (b) were clarified
specifically to allow an owner or operator of a BOPF shop that normally
operates two furnaces with overlapping cycles to shut down one furnace
during compliance tests for both mass and visible emissions. A new
provision also was added that requires the owner or operator to operate
the secondary emission control system for the furnace being tested at
exhaust ventilation rates (or levels) through each duct of the system
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that are appropriate for single-furnace operation. Following the
compliance test, the owner or operator must operate the system so that
exhaust ventilation rates (or levels) through each duct of the secondary
system are no lower than 90 percent of the exhaust ventilation rates
(or levels) established for each duct during the most recent compliance
test. The rationale for this change is discussed in Chapter 2, Sec-
tion 2.7, entitled "Equipment, Design, and Operating Specifications."
Section 60.145a was also clarified to define specifically the
period for hot metal transfer or skimming visible emission observations.
For both hot metal transfer and skimming, visible emission observations
begin with the start of the operation and terminate 3 minutes after
completion of the operation. The final rules also require that for
visible emission compliance tests, all visible emission observations
are to be identified and recorded in conjunction with the starting
times and stopping times of regulated operations in the steel production
cycle. The final rules require the use of 3-minute averages for
visible emission observations by Reference Method 9.
Section 60.145a also was expanded to.include instructions for
determining compliance with the 5-percent opacity standard and the
0.010-gr/dscf concentration standard for the secondary emission collec-
tion device. To determine compliance with the opacity standard, the
owner or operator would construct consecutive 3-minute averages for
each steel production cycle. Compliance would be achieved if no
3-minute average exceeded 5 percent. To determine compliance with the
mass standard, the owner or operator would determine the concentra-
tion of particulate matter in exhaust gases exiting the secondary
emission collection device, according to Reference Method 5. Compli-
ance would be achieved if the measured value did not exceed 23 mg/dscm
(0.010 gr/dscf). Additionally, instructions for determining compli-
ance with the proposed roof monitor opacity standard for bottom-blown
furnaces were deleted from the final rules.
1-1.2 Subpart N Amendments
Subpart N contains standards of performance that regulate primary
emissions of particulate matter from BOPF's constructed, reconstructed,
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or modified after June 11, 1973. On January 20, 1983, minor amendments
were proposed for Subpart N BOPF's constructed, reconstructed, or
modified between June 11, 1973, and January 20, 1983. These proposed
amendments did not revise the existing emission limit of 50 mg/dscm
(0.022 gr/dscf) for mass emissions of particulate matter from the
primary emission control device or the .existing opacity limit for
visible emissions exiting the primary emission control device. The
existing standard limits visible emissions exiting the primary emission
control device to an opacity of less than 10 percent, except that an
opacity greater than 10 percent but less than 20 percent may occur
once per steel production cycle. Additionally, no changes were proposed
to the existing monitoring or reporting requirements. The proposed
amendments did revise the test method instructions for sampling of
mass emissions by Reference Method 5. The existing standard required
a sampling rate of at least 0.9 dscm/hr (0.53 dscf/min); the proposed
amendments required a minimum sample volume of at least 0.9 dscm
(32 dscf). It should be noted that the minimum sample volume of
9.9 dscm (32 dscf) proposed under subparagraph (b)(l) was the result
of a Federal Register misprint; a minimum sample volume of 0.9 dscm
(32 dscf) was intended. With the exception of the sample volume
requirement, no other changes to the test methods and procedures for
determining compliance with the mass or visible emission standards
were proposed for these Subpart N BOPF's.
The proposed amendments also expanded the definition of a "basic
oxygen furnace" to exclude specifically open hearth, blast, or reverbera-
tory furnaces. No other definitional changes applicable to Subpart N
BOPF's were proposed.
A number of changes have been made since proposal to the final
standards for these Subpart N BOPF's. The proposed minimum sample
volume requirement has been increased to at least 1.5 dscm (53 dscf).
This revision is discussed in Chapter 2, Section 2.6, entitled "Emission
Testing and Monitoring." With the exception of this increased sample
volume requirement, no changes have been made to the existing test
methods and procedures for determining compliance with the mass and
opacity limits for primary emission control device by these Subpart N
BOPF's.
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Since proposal on January 20, 1983, EPA has become aware of a
difference in furnace cycle time between top-blown and bottom-blown
furnaces that may impact measured emission concentrations for those
facilities regulated under Subpart N. Bottom-blown furnaces in general
have shorter oxygen blowing periods than top-blown furnaces. The
testing provisions for those BOPF's constructed, reconstructed, or
modified after June 11, 1973, but on or before January 20, 1983, allow
testing from the beginning of the oxygen blow, or scrap preheat if
practiced, until just prior to tapping. The bulk of the particulate
emissions.occur during the oxygen blow, however. With a shorter
oxygen blowing period and roughly the same length nonblowing period as
top-blown furnaces, the bottom-blown furnaces are allowed a greater
proportion of test time during nonblowing periods, thus tending to
dilute the measured particulate concentration more than is allowed for
top-blown furnaces. To remedy this inequity due to furnace cycle
differences, EPA intends to propose revised sample period requirements
and mass standards as may be appropriate for top-blown and bottom-blown
furnaces under Subpart N as part of the 4-year NSPS review cycle.
No changes were proposed to the monitoring requirements specified
in §60.143 of the existing standards. The final rules would continue
these requirements with certain minor changes. Under §60.143(b)(2), a
monitoring device is required for the continuous measurement of the
water supply pressure to the control equipment, and the pressure
sensor or tap must be located close to the water discharge point. The
existing standards then state that the Administrator may be consulted
for approval of alternative locations for the pressure sensor or tap.
Under the final rules, alternative locations for the pressure sensor
or tap must be approved in advance by the Administrator. Also, the
word "continuous" was changed to "continually" to avoid confusion with
continuous monitoring system requirements specified under the General
Provisions of 40 CFR Part 60. Section 60.143 of the existing standards
also requires quarterly reports of all monitoring measurements over
any 3-hour period that averages more than 10 percent below the average
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levels maintained during the most recent performance test for
demonstrating compliance with the mass standards. The final standards
reduce the reporting frequency from quarterly to semiannually.
No changes to the definition for a BOPF have been made since
proposal. However, §60.141 of the final rules includes a revised
definition of "steel production cycle" for Subpart N BOPF's and a new
definition for "primary emissions." For Subpart N BOPF's (i.e.,
constructed, reconstructed, or modified after June 11, 1973, but on or
before January 20, 1983), the existing definition of "steel production
cycle" has been expanded to include sampling (vessel turndown and
turnup) operations. "Primary emissions" means particulate matter
emissions from the BOPF generated during the steel production cycle
and captured by the primary emission control system. Also, the
definition of "startup" was deleted from §60.141 because a definition
is now included in the General Provisions of 40 CFR Part 60.
Also on January 20, 1983, amendments to Subpart N were proposed
to regulate BOPF's constructed, reconstructed, or modified after
January 20, 1983. These proposed standards adjusted the mass emissions
limits and the test methods and procedures for determining compliance.
For BOPF's with a closed hood primary emission control system, the
proposed amendments limited mass emissions of particulate matter to no
more than 68 mg/dscm (0.030 gr/dscf), as measured for the primary
oxygen blow. For BOPF's with an open hood primary emission control
system, mass emissions of particulate matter were limited to no more
than 50 mg/dscm (0.022 gr/dscf), as measured for the primary oxygen
blow. The proposed amendments to the test methods and procedures for
sampling of mass emissions by Reference Method 5 specified that sampling
for each run must continue for an integral number of primary oxygen
blows with a total duration of at least 60 minutes. A minimum sample
volume requirement of 0.9 dscm (32 dscf) also was proposed.
No changes were proposed to the existing opacity standard for
primary emission control devices. Under the proposed amendments,
visible emissions from control devices for open or closed hood primary
control systems were limited to no more than 10 percent opacity,
except that an opacity greater than 10 percent but less than 20 percent
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could occur per steel production cycle. No changes to the test methods
and procedures for determining compliance with the opacity limit were
proposed.
A proposed definition for "primary oxygen blow" also was added to
§60.141. The proposed definition defined "primary oxygen blow" as the
period in the steel production cycle of a BOPF during which a high
volume of oxygen-rich gas is introduced to the bath of molten iron by
means of a lance inserted from the top of the vessel or through tuyeres
in the bottom or the bottom and sides of the vessel. Reblows were
excluded from the proposed definition, as was the introduction of
nitrogen through tuyeres in the bottom or bottom and sides of the
vessel.
The final Subpart N standards for BOPF's constructed, reconstructed,
or modified after January 20, 1983, continue the proposed requirements
with few exceptions. No changes to the adjusted limits for mass emis-
sions from open or closed hood primary control systems have been made
since proposal, although a new operational requirement has been added.
During and after any compliance test, the owner or operator must
operate the gas cleaning device during any reblow in a manner identical
to operation during the primary oxygen blow. The final rules require
these BOPF's to determine compliance with the adjusted mass emission
limits by sampling during the primary oxygen blow. No changes to the
proposed definition of "primary oxygen blow" have been made since'
proposal. Except for an increased sample volume requirement, no
changes to the Reference Method 5 test methods and procedures for
determining compliance with adjusted mass emission limits have been
made since proposal. The proposed minimum sample volume requirement
of 0.9 dscm (32 dscf) has been increased to at least 1.5 dscm (53 dscf).
This change is discussed in Chapter 2, Section 2.6, entitled "Emission
Testing and Monitoring." As proposed, shorter sampling times and
smaller sample volumes are permitted when necessitated by process
variables or other factors, subject to approval by the Administrator.
No changes have been made to the visible emission limit applied
to these BOPF's. As proposed, visible emissions from control devices
for open or closed hood primary control systems are limited to no more
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than 10 percent opacity except that an opacity greater than 10 percent
but less than 20 percent may occur once per steel production cycle.
Under the final rules, compliance with the visible emission standard
is determined according to the provisions of the existing primary
standard. However, the definition of "steel production cycle" for
these BOPF's has been revised since proposal to include specifically
sampling (vessel turndown and turnup) and deslagging operations.
BOPF's constructed, reconstructed, or modified after January 20,
1983 also are subject to the amended monitoring and reporting require-
ments. As discussed previously, §60.143 has been clarified to require
advance approval by the Administrator for alternative locations for
the monitoring device pressure sensor or tap. The final standards
also reduce the frequency of reporting requirements from quarterly to
semiannually.
1.2 SUMMARY OF IMPACTS OF PROMULGATED ACTION
1.2.1 Alternatives to Promulgated Action
The regulatory alternatives are discussed in Chapter 6 of'the
background information document (BID) for the proposed standards.
These regulatory alternatives reflect the different levels of emission
control from which one is selected that represents best demonstrated
technology (BDT), considering costs, nonair quality health, and environ-
mental and economic impacts for secondary emission control of BOPF's.
Regulatory Alternative II, the alternative selected as the basis of
the proposed secondary emission standards, was revised to account for
withdrawal of the roof monitor opacity standard for bottom-blown
furnaces. As revised, Regulatory Alternative II includes BDT controls
for top-blown furnaces and for hot metal transfer stations and skimming
stations used with bottom-blown or top-blown furnaces.
1.2.2 Environmental Impacts of Promulgated Action
The regulatory alternatives and their environmental impacts are
discussed in Chapters 6 and 7 of the BID for the proposed standards.
The environmental impacts remain unchanged since proposal. Withdrawal
of the proposed roof monitor opacity standard for secondary emissions
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from bottom-blown furnaces would not affect the environmental impacts
because impacts for the period 1981 through 1986 were based on estimates
of increased capacity projected for top-blown furnaces.
Comments received from the Office of Water indicate that the gas
cooling and conditioning system used with an electrostatic precipitator
(ESP) must be designed as a total evaporation system because the steel
industry effluent regulation (40 CFR 420, May 27, 1982) specifies no
discharge from these systems. Text from the BID for the proposed
standards also has been revised to include a further discussion of the
water pollution impact of Regulatory Alternative III if a wet or
semiwet ESP were used in lieu of other control systems. A detailed
discussion of these revisions may be found as Item IV-B-7 in Docket
No. A-79-6. With the changes noted in this docket submission, the
analysis of environmental impacts in Volume I of the BID is now con-
sidered the final environmental impact statement (EIS) for the promul-
gated standards.
1.2.3. Energy and Economic Impacts of Promulgated Actions
Energy and economic impacts are discussed in Chapters 7, 8, and 9
of the BID for the proposed standards. These estimated nationwide
impacts have remained unchanged since proposal.
Further analysis of secondary emission control technologies
indicates that the cost effectiveness of the control technologies that
can be used to comply with the standards ranges from $1,665 to $3,727
per ton of particulate matter removed for furnace emissions and from
$1,755 to $3,100 per ton of particulate matter removed for hot metal
transfer stations. In addition, new BOPF's may be able to employ
lower cost, innovative hot metal transfer controls. However, the
aggregated cost effectiveness of $2,245 per ton for secondary emission
controls has not been revised since proposal.
1.2.4 Other Considerations
1.2.4.1 Irreversible and Irretrievable Commitment of Resources.
None of the regulatory alternatives examined would result in the
irreversible or irretrievable commitment of resources in that a tradeoff
is made between short-term environmental gains at the expense of
long-term environmental losses or vice versa.
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The final regulations are standards of performance and therefore
do not require the use of any particular control technology with which
to achieve compliance. The regulatory alternative selected as the
basis of the standards (Regulatory Alternative II) would allow the
continued use of both types of primary control systems (open and
closed hood) currently favored by the industry. In addition, the
standards would not preclude the use of any other technology capable
of achieving the emission limits and would encourage the use of
innovative technology such as fume suppression systems.
1.2.4.2 Environmental and Energy Impacts of Delayed Standards.
Delay of promulgated secondary emission standards for this source
category was not considered a regulatory alternative because adequately
demonstrated control technology exists upon which the final standards
can be based. Also, construction, modification, or reconstruction of
three BOPF shops is estimated to commence during the 5-year period
following proposal of the standards. Nationwide uncontrolled secondary
and controlled primary emissions of particulate matter at these shops
would total about 3,221 Mg/yr (3,551 ton/yr) in the absence of the
proposed standards. These emissions would be in addition to the
uncontrolled secondary emissions from existing shops.
1.2.4.3 Urban and Community Impacts. The promulgated standards
will have a beneficial urban and community impact. Reduction in
particulate matter will reduce health risks for workers and the com-
munities surrounding new BOPF steelmaking facilities and improve the
overall environmental quality.
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2. SUMMARY OF PUBLIC COMMENTS
A total of five letters commenting on the proposed standards and
the background information document (BID) were received. A public
hearing was not requested during the prescribed period; consequently,
no public hearing was held. A list of the commenters, their affilia-
tions, and the U.S. Environmental Protection Agency (EPA) docket
numbers assigned to their correspondence is given in Table 2-1.
For the purpose of orderly presentation, the comments have been
categorized under the following topics:
1. Emission Data
2. Affected Facilities
3. Best Demonstrated Technology
4. Numerical Emission Limits
5. Visible Emission Standards
6. Emission Testing and Monitoring
7. Equipment Design and Operating Specifications
The comments, the issues they address, and EPA's responses are
discussed in the following sections of this chapter.
2.1 EMISSION DATA
2.1.1 Comment: (IV-D-2) One commenter suggested that particulate
matter emission factor reports for tests of basic oxygen process
furnace (BOPF) hot metal charging and tapping at Republic Steel Corporation,
Kaiser Steel Company, and Inland Steel Company be included in the data
analysis of Volume I of the BID. He also believed that a report on
particulate mass and particle size measurements for the hot metal
desulfurization plant at Kaiser Steel Company should have been included.
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TABLE 2-1. LIST OF COMMENTERS ON PROPOSED STANDARDS FOR THE BOPF
NEW SOURCE PERFORMANCE STANDARD (NSPS) REVISION
Docket item number1
Commenter and affiliation
IV-D-1
IV-D-2
IV-D-3
IV-D-4
IV-D-5
E. F. Young, Jr.
American Iron and Steel Institute
1000 16th Street, N.W.
Washington, DC 20036
Date: March 15, 1983
Jim Steiner
Pape and Steiner Environmental
Services
5801 Norris Road
Bakersfield, CA 93308
Date: April 4, 1983
D. A. Woodring
Republic Steel Corporation
P.O. Box 6778
Cleveland, OH 44101
Date: April 4, 1983
David M. Anderson
Bethlehem Steel Corporation
Bethlehem, PA 18016
Date: April 4, 1983
Frank P. Partee
Compliance and Liaison Department
Ford Motor Company
One Parklane Boulevard
Dearborn, Michigan 48126
Date: April 13, 1983
The docket number for this project is A-79-6. Dockets are on file at EPA
Headquarters in Washington, DC, and at the Office of Air Quality Planning
and Standards (OAQPS) in Durham, NC.
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Response: Not all of the reports named by the commenter had been
finalized and distributed at the time emission data were being analyzed.
Emission factor data used in the BID were taken from "Particulate
Emission Factors Applicable to the Iron & Steel Industry" (EPA-450/4-
79-028), which contains material similar to that in the emission
factor reports named by the commenter (II-A-46). This earlier report
was the source for revised emission factors published in "Supplement
Number 11 for Compilation of Air Pollutant Emission Factors, Third
Edition," AP-42, published by EPA, October 1980. Information in the
test reports named by the commenter and not used in this review of the
BOPF standard will be evaluated during the next 4-year review of the
BOPF standard. The selection of emission factors used in the development
of the standards is further discussed in the response to comment
2.2.3.
2.1.2 Comment: (IV-D-2) One commenter suggested that the teeming
emission factor of 35 g/Mg (0.07 Ib/ton) of steel is based on unleaded
heats and that leaded heats have an emission factor of 0.81 Ib/ton,
72 percent of which is of inhalable particle size. He also recommended
that secondary emissions from teeming be included in the proposed
rulemaking:
Response: The commenter is correct in suggesting that an unleaded
heat emission factor was used to assess teeming emissions. While the
leaded heat emission factor is considerably larger, available informa-
tion suggests that leaded heats comprise only a small portion of the
total number of BOPF heats. In the absence of specific information to
the contrary, a determination was made that the emission factor for
unleaded heats would be more representative of normal industry practice.
The rationale for not controlling teeming at present is discussed in
the response to comment 2.2.4.
2.2 AFFECTED FACILITIES
2.2.1 Comment: (IV-D-1 and IV-D-4) Two commenters questioned the
proposed definitions of the BOPF vessel, hot metal transfer station,
and skimming station as separate, affected facilities. The commenters
believe that construction, modification, or reconstruction of a hot
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metal transfer or skimming station could subject an existing BOPF shop
to the proposed secondary emission opacity standard. They also pointed
out that because opacity readings are taken at shop openings, vents,
and monitors (where they could be intermingled with emissions from
unregulated operations in the shop), enforcement officials could
require compliance from the entire existing shop.
Response: The choice of the affected facility for this standard
is based on interpretation of Section 111 of the Act and judicial
construction of its meaning. Under Section 111, the NSPS must apply
to "new sources." "Source" is defined as "any building, structure,
facility, or installation which emits or may emit any air pollutant"
[lll(a)(3)]. Most industrial plants, however, consist of numerous
pieces or groups of equipment that emit air pollutants and that might
be viewed as "sources." The term "affected facility" is used, there-
fore, to designate the equipment, within a particular kind of plant,
which is chosen as the "source" covered by a given standard.
.When the affected facility is chosen, a decision must be made
concerning which pieces or groups of equipment are the appropriate
units for separate emission standards in the particular industrial
context involved. This decision is made by examining the situation in
light of the terms and purpose of Section 111. One major consideration
in this examination is that the use of a narrower definition results
in bringing replacement equipment under the NSPS sooner; if, for
example, an entire plant were designated as the affected facility, no
part of the plant would be covered by the standard unless the plant as
a whole is "modified." If, on the other hand, each piece of equipment
is designated as the affected facility, as each piece is replaced, the
replacement piece will be a new source subject to the standard.
Because the purpose of Section 111 is to minimize emissions by applica-
tion of the best demonstrated control technology (considering cost,
other health and environmental effects, and energy requirements) at
all new and modified sources, the presumption is that a narrower
designation of the affected facility is proper. This designation
ensures that new emission sources within plants will be brought under
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the coverage of the standard as they are installed. It was for this.
reason that the emission sources were defined as separate, affected
facilities.
As explained in 48 FR 2658, the proposed standards of performance
for secondary emissions would apply only to a BOPF, hot metal transfer
station, or skimming station that commenced construction, modification,
or reconstruction after January 20, 1983. (Note that the final rules
apply only to top-blown BOPF's and to hot metal transfer stations or
skimming stations used for bottom-blown or top-blown BOPF's.) It
should be noted that although a plant may contain both affected facil-
ities and existing, nonaffected facilities, the modification or recon-
struction of an existing, nonaffected facility would not subject any
other existing nonaffected facility to the requirements of the proposed
regulation. Only the facility constructed, modified, or reconstructed
would become subject to the standards of performance. For example,
the addition of a new furnace to an existing shop would subject only
the new furnace to the secondary emission standards; an existing hot
metal transfer or skimming station would not be affected unless it was
also modified or reconstructed. The effects of new construction,
modifications, and reconstructions on affected and nonaffected facil-
ities are discussed further in Chapter 5 of the BID for the proposed
standards.
The proposed standards also recognize that, at times, visible
emissions from the shop roof monitor (or other building openings) may
occur from unaffected facilities or unregulated ancilliary operations.
For this reason, the final rules allow the owner or operator to operate
only one furnace during compliance testing for mass and visible emission
limits. The owner or operator also may choose to suspend all unaffected
shop operations during the test. The final regulation also requires
that all visible emissions be identified in conjunction with the
starting and stopping times of regulated process operations. Conse-
quently, the use of a process observer is encouraged. A process
observer inside the shop during the testing can reduce substantially
the possibility that emissions from unaffected facilities or operations
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are included in the opacity observations. These provisions are adequate
to ensure that emissions from other operations or facilities are not
adversely incorporated in the opacity observations.
2.2.2 Comment: (IV-D-4) One commenter requested clarification of
the definitions for the affected facilities. This commenter indicated
a potential discrepancy between §60.140a(a) of the regulation, which
cites the affected facilities, and §60.142a(a), which contains the
proposed secondary emission limits. The proposed emission limits
appear to apply only to BOPF secondary emissions (i.e., emissions
escaping the BOPF primary control system). Consequently, the proposed
emission limits would not apply to hot metal transfer and skimming
stations.
Response: Under §60.140a(a), the BOPF, hot metal transfer station,
and skimming station are designated as the affected facilities subject
to the proposed secondary emissions standards. Section 60.142a specifies
the proposed emission limits for secondary emissions from affected
facilities. The hot metal transfer station and the skimming station,
as affected facilities, are subject to the proposed standards for
particulate matter under §60.142a.
The proposed standards define secondary emissions as "particulate
emissions that escape capture from the BOPF primary control system."
Hot metal transfer and skimming operations do not generally occur in
proximity to the furnace. Consequently, emissions from these operations
are not captured by the BOPF primary control system. Because these
emissions escape capture by the furnace control system, they are
considered secondary emissions. Therefore, the proposed standards for
secondary particulate matter apply to secondary emissions from the
furnace, in combination with "secondary" emissions from hot metal
transfer and skimming operations. The final rule clarifies the
definition of "secondary emissions" by specifically including emissions
from hot metal transfer and skimming. Also included in the final
definition are particulate matter emissions that escape from openings
in the primary emission control system, such as from lance hole openings,
gaps or tears in the ductwork of the primary emission control system,
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or leaks in hoods. Similar clarifying changes were also made to the
definition of "primary emissions," and new definitions for "primary
emission control system" and "secondary emission control system" also
were added to the final rule.
2.2.3 Comment: (IV-D-4) One commenter questioned the selection of
affected facilities, based on "over-stated" emission factors and, in
one case, lack of supporting data. He pointed out that the emission
factors for uncontrolled secondary emissions of particulate matter
from hot metal transfer and BOPF charging are considerably higher than
are emission factors used in two more recent reports, "Particulate
Emission Factors Applicable to the Iron and Steel Industry" (EPA-450/4-
79-028) and "Fugitive Dust Emission Factor Update for AP-42" (Draft).
The commenter also stated that uncontrolled emissions from hot metal
transfer and charging emissions from top-blown vessels are insignifi-
cant compared to BOPF primary (oxygen blowing) emissions. In addition,
the commenter questioned the legal justification for controlling
skimming emissions when no data were available regarding the magnitude
of these emissions and when no attempt was made to quantify these
emissions.
Response: The BOPF, hot metal transfer station, and skimming
station were selected for regulation in the proposed rules because
adequately demonstrated control technology exists, considering costs,
upon which the proposed standards can be based, and because these
facilities account for about 1,355 ton/yr of uncontrolled secondary
emissions of particulate matter for a typical BOPF shop operating two
272-Mg (300-ton) top-blown furnaces.
The emission factors used to estimate uncontrolled secondary
emissions were the most current factors available at the time of the
data analysis. It should be noted that AP-42 (Supplement 11) provided
one set of emission factors for selected operations. However, a
review of these emission factors revealed that they were based on
tests for bottom-blown vessels. The source of these AP-42 emission
factors was the 1979 EPA report, "Particulate Emission Factors Applic-
able to the Iron and Steel Industry" (EPA-450/4-79-028). Because this
2-7
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latter report also Included the best emission factors currently avail-
able for top-blown furnaces, these top-blown furnace emission factors
were used in the data analysis.
Uncontrolled secondary emissions from hot metal transfer at a
typical shop are estimated at 286 ton/yr for top-blown furnaces, based
on an emission factor of 0.19 Ib/ton hot metal poured. Controls
(local hooding ducted to a baghouse) are available for the hot metal
transfer station at a reasonable cost per ton of emission reduction.
For these reasons, the hot metal transfer station was selected for
control as an affected facility.
The skimming operation in new plants is generally performed at
the hot metal transfer station, or immediately adjacent to it, following
the hot metal transfer operation. No emission factor for skimming had
been reported in AP-42 or in "Particulate Emission Factors Applicable •
to the Iron and Steel Industry" at the time of the data analysis.
However, visible emissions from this operation have been observed at
two plants based on Reference Method 22 (II-A-50, II-A-51). Because
these emissions can be controlled by the same capture and collection
system as used for hot metal transfer emissions, at no significant
additional cost, the skimming station also was selected as an affected
facility.
The vast majority of BOPF secondary emissions are attributable to
the various operations comprising the steel production cycle of the
BOPF vessel. These operations include scrap charging, hot metal
charging, blowing, turndown, and tapping. No emission factors were
available at the time of the data analysis to quantify secondary
emissions from scrap charging, the primary blow, or vessel turndown.
However, visible emissions from these operations have been observed at
the roof monitors of several shops through Reference Method 22 (II-A-50,
II-A-52, II-A-53, and II-A-54).
Emission factors are available to estimate secondary emissions
from hot metal charging and tapping. Based on the highest quality
emission factor for top-blown furnaces provided in "Particulate Emission
Factors Applicable to the Iron and Steel Industry" (0.4 Ib/ton of hot
2-8
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metal poured), secondary emissions from hot metal charging are estimated
at 603 ton/yr for a typical shop. Secondary tapping emissions are
estimated at 466 ton/yr for top-blown furnaces at a typical shop,
based on the emission factor of 0.291 Ib/ton of steel as reported in
"Particulate Emission Factors Applicable to the Iron and Steel Industry."
It is true that uncontrolled secondary emissions from hot metal
transfer and charging in top-blown vessels are only about 3.5 percent
of BOPF primary (oxygen blowing) emissions. The emission factor for
the blow, 28.6 Ib/ton, can be compared to an emission factor of about
1 Ib/ton for the combined effect of uncontrolled emissions from hot
metal transfer and charging. However, uncontrolled secondary emissions
from these operations combined total about 1,355 ton/yr at a typical
shop. These are significant emissions for a typical shop and are
considered even more significant on a nationwide basis. Uncontrolled
secondary emissions of particulate matter from these operations consti-
tute a major emission source, even when considered separate operations.
Data are available with which to quantify these emissions and controls
are available at a reasonable cost with which to reduce these emissions.
Consequently, these operations were selected for regulation based on
their own merits.
Uncontrolled secondary emissions emanating from furnace operations
during the steel production cycle constitute the bulk of the secondary
emissions from the BOPF steelmaking process. Emission factors are
available to quantify secondary emissions from charging and tapping--
the operations wherein emissions are most likely to escape capture by
the primary hood. For top-blown furnaces, secondary emissions from
charging and tapping combined total about 1,069 ton/yr. Controls are
available for these emissions at a reasonable cost. These controls
will also capture and collect secondary emissions from some other
furnace operations at no additional cost. For these reasons, the BOPF
was selected as an affected facility under the proposed standards, as
were the hot metal transfer station and skimming station.
The affected facilities identified in the proposed rules have
been revised since proposal. Under the final rules, the affected
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facilities are the top-blown BOPF and hot-metal transfer and skimming
stations used for a bottom-blown or a top-blown BOPF. The rationale
for this change is discussed in response to comment 2.4.4.
2.2.4 Comment: (IV-D-2) One commenter disagreed that the cost of
controlling ancillary operations not subject to the proposed standards
would be highly disproportionate to the amount of particulate collected.
The commenter indicated that teeming and hot metal desulfurization
produce significant quantities of particulates compared to regulated
secondary emission sources and that the same control technology (local
hooding ducted to a baghouse) is also applicable to these unregulated
ancillary operations. These ancillary operations may be located in
proximity to the hot metal transfer station, allowing the use of one
common control system. The commenter provided uncontrolled emission
factors for hot metal desulfurization, based on a total of 10 recent
tests on torpedo cars at Kaiser Steel. He further questioned the
estimate for the quantity of emissions resulting from these unregulated
ancillary operations (8 percent of identified fugitive emissions from
BOPF shops)., This commenter recommended that tes.ts be performed to
quantify emissions from these ancillary operations and that the control
of these unregulated ancillary operations be considered under the
proposed rulemaking.
Response: As explained at 48 FR 2660 and 2661, certain ancillary
operations were not selected for regulation under the proposed secondary
emission standards. These operations include hot metal desulfurization,
dekishing, teeming, slag handling, ladle maintenance, and flux handling.
Prior to proposal of the secondary emission standards, no Reference
Method 9 visible emission data were available with which to characterize
emissions from hot metal desulfurization operations, although visible
emissions were observed at one plant according to Reference Method 22
procedures (II-A-51, II-B-51, II-B-52, and II-B-54). Consequently,
visible emission testing by Reference Method 9 was conducted at a
second plant. Mass emission test data also were collected at this
plant, but the results of the mass emission testing have been received
only recently and currently are undergoing review. It should be noted
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that the emission factors supplied by the commenter were based on this
same mass test. However, preliminary review has indicated that additional
test data are required to portray emissions from this operation accurately,
because hot metal desulfurization methods vary widely from plant to
plant and may not be applied to all types of metal produced. For
these reasons, this operation was not selected for control under the
proposed standards at present. Rather than delay promulgation of the
proposed standards to incorporate an evaluation of hot metal desulfuri-
zation, control of these emissions will be considered during the next
4-year review of the primary and secondary emissions standards.
Remaining ancillary operations not directly associated with the
BOPF vessel (other than hot metal transfer and skimming) include
teeming, dekishing, slag handling, ladle maintenance, and flux handling.
Except for teeming, no emission factors are available to quantify
uncontrolled particulate matter emissions from these operations,
although low-level visible emissions from these operations have been
observed. . Based on a review of the estimate contained in the preamble
(that ancillary .operations contribute about 8 percent of total BOPF
fugitive emissions at a typical shop), it is agreed that particulate
emissions from these sources may be greater than previously estimated.
However, the lack of quantitative emission data, coupled with the
absence of good demonstrated control technology, prevented the selection
of these operations for control at present. Should additional data
become available, these operations will also.be evaluated during the
next 4-year review of the primary and secondary standards.
For teeming operations, AP-42 (Supplement 11) reported an emission
factor of 0.07 Ib/ton of steel, applicable to both top- and bottom-
blown furnaces. Based on this emission factor, uncontrolled secondary
emissions of a typical shop are estimated at 112 ton/yr. Even though
these emissions are not insignificant, observations of visible emissions
did not indicate measurable levels at BOPF shop roof monitors. Although
controls are used for teeming of leaded steel, leaded steel represents
a relatively small percentage of total steel production. Application
of these controls on the scale required to fit teeming of all steel
produced needs further study before a decision to regulate can be
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made. Furthermore, many BOPF shops are installing continuous casting
facilities. The general trend is toward this energy and labor saving
production step that will reduce the amount of steel teemed (IV-J-1).
For the above reasons, teeming was not selected as an emission source
for .regulation at present. However, this operation also will be
reviewed and considered for control during the next 4-year review of
the primary and secondary standards.
2.3 BEST DEMONSTRATED TECHNOLOGY (BDT)
2.3.1 Comment: (IV-D-2) One commenter disagreed with the preamble
statement (p. 2661) that certain operating practices (e.g., clean
scrap, slow pouring, careful positioning of the hot metal ladle, and
proper furnace tilt angle) have been demonstrated only for top-blown
furnaces. He stated that during testing of the Republic Steel bottom-
blown furnace (Q-BOP), these practices were used and appeared to
generate few or no fugitive emissions that escaped the secondary
control system. This control was achieved despite the improper operat-
'ing condition of the control system (one fan on primary hood and one
on secondary hood, rather than two on secondary) during the test.
Consequently, roof monitor opacity reached a maximum of 15 percent but
averaged less than 10 percent over the period of hot metal addition.
However, according to the commenter, these conditions were not achieved
consistently during the test program.
Response: As the commenter pointed out, periods existed during
which the indicated operating practices were accompanied by few or no
fugitive emissions that escaped the secondary control systems. As he
also pointed out, these conditions were not achieved consistently. In
our engineering judgment, this lack of consistency indicates that the
operating practices mentioned by the commenter are not demonstrated
for bottom-blown furnaces. Therefore, the operating practices were
not included as an element of BDT upon which the proposed standard for
Q-BOP's was based. This lack of consistency was a contributing factor
to our conclusion that the Republic Steel System does not truly represent
BDT for bottom-blown controls. The rationale for withdrawal of the
proposed Q-BOP standard is discussed further in response to comment
2.4.4.
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2.3.2 Comment: (IV-D-2) One commenter questioned the conclusion
that performance of roof-mounted electrostatic precipitators (RMESP's)
may be equivalent to or better than BDT for secondary emission collec-
tion when no data were available to assess RMESP performance. The
commenter also questioned why a Japanese RMESP was not evaluated to
support the proposed standards. This commenter pointed out that a
baghouse can handle secondary emissions containing hard-to-precipitate
kish particles and significant amounts of fine particulate emitted in
large bursts more efficiently than can an RMESP. Although the commenter
supported the possible RMESP waiver for innovative technology, he
suggested that the conclusion that the RMESP may be equivalent to (or
better than) BDT at a lower cost should be verified.
Response: Section lll(j) of the Clean Air Act provides that an
owner or operator of an affected facility may request a waiver from
one or more requirements of the standards to encourage the use of the
innovative control system. Findings that the technology has not been
demonstrated adequately and that it has either a substantial likeli-
hood of achieving greater emission reduction than required by the NSPS
or of achieving equivalent emission reduction at Tower cost (including
energy and nonair environmental costs) are necessary for an owner or
operator to obtain an innovative technology waiver for other requirements
of the standard. Once a waiver has been issued, its terms must include:
(1) assurance that the source emissions will not prevent attainment
and maintenance of national ambient air quality standards (NAAQS's);
(2) assurance that the technology will function properly; (3) a time
limit for testing the technology not to exceed 7 years from issuance,
4 years from startup, or until the technology proves unworkable; and
(4) a restriction to that portion of the source on which the technology
is used. The commenter is correct in noting that no data were available
to quantify the performance, costs, and other impacts associated with
the use of RMESP's. However, as indicated in the proposed rulemaking,
there were qualitative indications that RMESP's have the potential to
be at least as efficient as, and more cost effective than, capture
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hoods ducted to a particulate collection device, which is the technology
on which the numerical standard is based. Some of this qualitative
information was obtained from RMESP's in Japan. Unfortunately, the
Japanese companies using the RMESP's would not permit the quantitative
evaluation of their control technologies.
The final rule in Subpart Na applying to visible emission opacity
from roof monitors represents the minimum level of control for secondary
emissions needed to comply and was based on data taken from plants
with best demonstrated conventional technology. Because there may be
an emission flow volume difference between the discharge of an RMESP
and the discharge of the more conventional BDT secondary systems, it
is not clear that RMESPs are necessarily equivalent to best technology.
Therefore, during any required case-by-case reviews, RMESP design will
also be considered.
Under the terms negotiated for any waiver granted, provisions
would be included to ensure that any RMESP installed to comply with
the NSPS would be designed and operated properly. Data collected
during the term of the waiver would be used to verify RMESP performance
•and costs. Should the performance and costs be demonstrated as equivalent
to or better than BDT, the inclusion of provisions specific to RMESP's
would be considered during the next 4-year review of Subpart Na.
2.3.3 Comment: (IV-D-1 and IV-D-3) Two commenters pointed out that,
while the proposed standards do not require the use of a specific
technology to meet the proposed emission limits, a steel producer
could experience difficulties in permit approval if the producer
desired to implement a technology not examined or discussed in the
preamble or BID for the proposed or promulgated rule. In this regard,
both commenters pointed to fume suppression, a relatively new technol-
ogy, which could provide the potential for eliminating or reducing the
need for particulate capture techniques. One commenter stated that
the cost to implement and operate this technology can be substantially
less than other control alternatives, with fume suppression providing
an equivalent performance. Accordingly, the commenters recommended
that this technology be examined as a viable alternative control
technique.
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Response: Before responding to the commenter's point, it is
important to note that permit approval is not required for NSPS's.
Any permit that would be required would be for State or local agencies.
It is agreed that in such cases the source may need to provide a basis
for concluding that compliance is probable. Data regarding fume
suppression were not available when Volume I of the BID was being
prepared. Since proposal, however, new information and data have been
obtained to support further the conclusion that fume suppression
systems may provide, at a lower cost, performance equivalent to that
of other control alternatives (IV-B-4). Because the standards of
performance for hot metal transfer stations are expressed as numerical
emission limits, an owner or operator may choose to install a fume
suppression system to control hot metal transfer emissions so long as
it can achieve compliance with the numerical limit.
Suppression techniques reduce iron oxide fuming above molten
metal or slag baths by inhibiting oxidation of the iron at the surface
of the bath. Oxidation is inhibited by blanketing the bath surface
with flame, steam, wet sand, or wet slag. To date, these techniques
have been applied experimentally to: (1) blast furnace iron tapping,
(2) blast furnace slag tapping, (3) open hearth tapping, (4) electric
furnace tapping, (5) hot metal transfer, (6) BOPF charging, (7) BOPF
tapping, and (8) BOPF lance hole emissions.
Preliminary data quantifying the performance of flame suppression
on a BOPF hot metal transfer station at U.S. Steel's Gary plant indicate
that opacity is reduced significantly with the use of flame suppression.
These data are provided in Table 2-2. Thus, while these techniques
are not yet demonstrated for other portions of the BOPF production
cycle, it appears that flame suppression (one of the several fume
suppression techniques) is capable of achieving emission reduction at
least equal to requirements of the proposed regulation during hot
metal transfer.
Moreover, because flame suppression eliminates the need for
capture and control devices, emission reductions may be achieved at
costs significantly below those of the BDT on which the standards are
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TABLE 2-2. HOT METAL TRANSFER FLAME SUPPRESSION EVALUATION
Number of 15-second
readings >20 percent
opacity observed per
hot metal transfer
0
1 to 5
6 to 10
11 to 15
16 to 20
>20
Percentage
No. 1
Without
flame sup-
pression
54.3
11.4
14.3
11.4
5.7
2.9
of total hot metal transfers observed
BOPF shop
With
flame supr
pression
96.0
4.0
0
0
0
0
No. 2 BOPF shop
Without
flame sup-
pression
68.3
15.1
8.6
4.3
2.6
1.1
With
flame sup-;
pression
89.2
5.6
5.2
0
0
0
Based on 70 hot metal
""Based on 50 hot metal
'Based on 65 hot metal
Based on 85 hot metal
transfers observed.
transfers observed.
transfers observed.
transfers observed.
based. The cost effectiveness of fume suppression applied to hot
metal transfer emissions is estimated at $633/ton of particulate
matter removed. Depending on the control scenario applied, this can
be compared to a cost effectiveness of $l,755/ton for a baghouse
collecting furnace secondary and hot metal transfer emissions and
$3,104-ton for a baghouse collecting only hot metal transfer emissions.
As described in the response to comment 2.3.2, for the purposes
of this NSPS, an innovative technology waiver may be granted to an
owner or operator desiring to install a fume suppression system to
meet the standards.
Under the negotiated terms of an innovative technology waiver,
the owner or operator would be granted an extended time period to meet
the visible emission standard. Fume suppression systems are exempt
from the mass and opacity emission limits for secondary emission
control devices because use of the fume suppression technique eliminates
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the need for other capture and collection equipment. Provisions would
be included in any waiver agreement to ensure that a fume suppression
system installed to meet the NSPS would be designed and operated
properly. Data collected during the term of the waiver would be used
to document the performance and costs of fume suppression for particulate
emission control. Should the performance and costs be equivalent to
or better than BDT, the inclusion of provisions specific to fume
suppression systems may be considered during the next 4-year review of
Subpart Na.
The final standards also contain a definition for fume suppression
systems. A fume suppression system is defined as "the equipment
comprising any system used to inhibit the generation of emissions from
steelmaking facilities by means of an inert gas, flame, or steam blanket
applied to the surface of molten iron or steel."
2.3.4 Comment: (IV-D-2) One commenter questioned the estimated
capture efficiency of 90 percent or more for auxiliary hooding and the
application of this estimated capture efficiency to bottom-blown
furnaces. He referred to tests conducted on the Republic Steel Q-BOP,
stating that: (1) this furnace did not have an auxiliary hood for
tapping, and the secondary control system demonstrated much less than
90 percent capture for tapping emissions; (2) at least seven mechanical
failure incidents occurred during the test (bell damper problems); and
(3) a capture effectiveness of 90 percent or more was demonstrated
on occasion (emphasis added by commenter) for hot metal addition
emissions. This commenter indicated that the preamble incorrectly
implied (p. 2661) that 90 percent capture had been demonstrated on a
continual basis at the time of the test program.
Response: The commenter's concern that 90 percent capture is not
continually attained rests on his observations during testing at the
Republic Steel Q-BOP. He correctly points out that the Republic
facility has no tapping hood.
The last two sentences of the Federal Register notice paragraph
to which the commenter refers are, "An enclosure with hoods located
over the charging and tapping areas may achieve a capture effectiveness
of 90 percent or better. This control system has been demonstrated
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for both top and bottom blown furnaces" (emphasis added). The
first sentence is meant to imply that there is a possibility rather
than a probability of 90 percent capture given sufficient hooding.
Because the Republic facility has no tapping hood, a capture efficiency
of less than 90 percent would be expected. The last sentence of the
paragraph is meant as a summarizing sentence for the entire paragraph
rather than as a continuation of the preceding sentence. The selection
of the Republic system as BDT for bottom-blown furnaces is further
discussed in the response to comment 2.4.4.
2.3.5 Comment: (IV-D-2) One commenter, in referring to the preamble
discussion of the capture efficiency of building evacuation systems
(p. 2661), asked if the system discussed (the roof monitor evacuation
system with baghouse controls at the No. 2 BOPF shop of Inland Steel,
East Chicago) handles only a portion of the total shop emissions
(i.e., those generated by the most recent furnace installation) or if
it handles emissions from the entire building.
Response: The capture system in question is a partial building
evacuation system applied only to the furnace charging aisle. A
curtain wall is installed between the charging aisle and the furnace
aisle to prevent substantial movement of charging emissions to the
furnace aisle. The system is used in conjunction with local hoods
within the furnace enclosure. Visual observation shows that the
evacuation rate for this partial building evacuation system (130 acms
or 275,000 acfm) is less than is required to prevent leakage from the
enclosed portion of the building even with the assistance of the local
hoods. For this reason, the Inland facility was not considered BDT
for secondary emission control.
2.4 NUMERICAL EMISSION LIMITS
2.4.1 Comment (IV-D-2) One commenter asserted that the proposed mass
emission standard for secondary emission collection devices (0.010 gr/
dscf) did not reflect the performance of baghouses, which was selected
as BDT for this application. The commenter argued that a properly
designed, operated, and maintained baghouse controlling emissions from
hot metal transfer, skimming, and other operations can achieve an
outlet emission rate of 0.005 gr/dscf.
2-18
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Response: The numerical emission limit of 0.010 gr/dscf proposed
for secondary emission collection devices is based on the data available
at proposal. The data base for the emission limit, as proposed,
includes data from hot metal transfer, partial building evacuation for
BOPF's, and full-cycle data for electric arc furnaces (EAF's). Other
operations that generate secondary BOPF emissions are not included in
the data base. While the commenter correctly states that certain
operations can be controlled to achieve an emission rate of 0.005 gr/
dscf, control of all pertinent operations has not been demonstrated
adequately at that level.
The data supporting the proposed standard do not support a lower
limit. It is agreed that new data, coupled with the transfer of
technology from EAF's, might support the lower limit recommended by
the commenter. However, without the benefit of public comment and
because it is hot clear whether other data reflect technology different
from the data on which the 0.010-gr/dscf limit is based, the final
rules do not revise the standard for secondary emission collection.
devices. Revising the standard to reflect tHe higher performance
level will be considered during the next 4-year review of Subparts N
and Na.
2.4.2 Comment: (IV-D-2) One commenter believes the numerical emissio'n
limit for the proposed revision to the existing particulate standard
for a closed hood furnace primary control device outlet should not be
raised to 68 mg/dscm (0.030 gr/dscf). The commenter stated that two
of three plants tested emitted particulates at or below the current
standard of 50 mg/dscm (0.022 gr/dscf) and one plant was found to be
just above the standard at 55 mg/dscm (0.024 gr/dscf). The commenter
asked why the proposed standard was raised to 68 mg/dscm (0.030 gr/dscm)
when the majority of the plants tested (two out of three) met the
existing standard.
Response: Selection of numerical emission limits must take into
account variability of control system performance and performance
measurements. Without accounting for this variability, the plants
using BDT, even those used as the basis for the standard, could fre-
quently be found to be violating the standard. One means of taking
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this variability into account is to use a statistical analysis approach.
Statistical analysis was used to aid in the selection of the proposed
revised standard, 68 mg/dscm (0.030 gr/dscf). The means and standard
deviations of the three test averages were computed for comparison,
after which an upper 95-percent prediction limit was computed based on
the standard deviation computed for the 15 individual test runs. The
numerical emission limit selected, 68 mg/dscm, was just above the
upper 95-percent prediction limit, 66 mg/dscm. Although the proposed
numerical limit is less stringent than the original, it nevertheless
requires application of BDT.
Data presented in Table 4-12 of the BID suggest that a lower
concentration limit for open hood furnaces may be possible. These
data show performance levels better than performance measured during
testing to support the existing NSPS limit of 50 mg/dscm (0.022 gr/dscf).
Determination of the equipment design, operating criteria, and process
variables responsible for producing lower emission concentrations from
the open hood furnaces will be examined during the next 4-year NSPS
review for consideration of a change in the concentration limit.'
2.4.3 Comment: (IV-D-1) One commenter pointed to unique problems
with Q-BOP's (bottom-blown furnaces) when certain grades of metallurgical
steel are made. Oxygen blowing as the vessel is turned down is required
for these types of steel, which results in emissions even greater than
during nitrogen blowing during typical vessel turndown. For this
reason, the commenter recommended that this issue be addressed and
that increased opacity limits for Q-BOP's be allowed when metallurgical
grades of steel that require oxygen blowing during vessel turndown are
made.
Response: The issue raised by the commenter, although not specif-
ically mentioned in the BID, was addressed during testing of the
Republic Steel Q-BOP system. Metallurgical steels with oxygen blowing
during turndown were made during some of the heats made during the
test periods. The opacity readings from these heats have been sum-
marized in the BID and have been considered part of the data base used
to propose the opacity limit for bottom-blown vessels. The impact of
oxygen blowing during turndown was adequately considered during analysis
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of this data base. The Republic system as the basis of the proposed
Q-BOP standard is further discussed in the response to the following
comment.
2.4.4 Comment: (IV-D-2) One commenter criticized the selection of
the proposed opacity limits for Q-BOP (bottom-blown) vessels. This
commenter stated that the proposed 60-percent opacity limit does not
reflect BDT because the Republic Steel Q-BOP system (upon which the
proposed emission limit is based) is inadequate for the following
reasons: (1) failure of the system to achieve 90 percent capture
effectiveness consistently during the testing program because of
secondary emission control system mechanical (bell damper) failures;
(2) poor design; and (3) poor maintenance. Rather, he recommended a
bottom-blown regulatory alternative consisting of an enclosure with
local hot metal addition (HMA) and tapping hoods exhausted to a baghouse
(or equivalent device) that can handle 600,000 acfm or the gas volumes
handled by the Bethlehem and J&L plants.
Response: The opacity limit proposed for bottom-blown vessels
was consistent with data for bottom-blown furnaces that were-available
at proposal. The effect of the commenter1s recommendation would be the
establishment of an emission limit at a level that has not been observed
in practice for bottom-blown furnaces. It is agreed that the performance
of controls on other sources, such as top-blown furnaces, suggests
that better performance should be achievable for bottom-blown furnaces
and raises doubt as to whether the proposed limits reflect the perform-
ance of BDT. The commenter also correctly implied that capture and
control of emissions from these vessels have not been demonstrated at
a level consistent with top-blown vessels. A more stringent limit
based on transfer of technology was not considered warranted in the
case of bottom-blown vessels because of the wide range of conditions
under which the vessels operate and the correspondingly wide range of
emissions from the vessels (see the preceding comment and response as
an example).
Based on this comment and further review, it has been determined
that better control will likely become available before the next
4-year review of the primary and secondary standards, and that the
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proposed opacity standard, if promulgated, would probably not reflect
BDT. In particular, it should be noted that revised State opacity
regulations adopted pursuant to the requirements of 40 CFR Part 52 are
much more stringent than the proposed standard. Because of these
findings, the proposed roof-monitor opacity limit for bottom-blown
vessels is being withdrawn from the final rules.
The requirement for limiting the opacity of visible emissions
produced by hot metal transfer and skimming in bottom-blown furnace
shops, however, is being retained. There are no significant process
differences between hot metal transfer and skimming in bottom-blown
furnace shops as opposed to top-blown furnace shops. Likewise,
equipment used to perform these processes is not necessarily different
in bottom-blown versus top-blown shops. Therefore, there is no reason
to believe that any significant difference should exist in emission
potential, either controlled or uncontrolled. For the above reasons,
the roof monitor opacity limit for hot metal transfer and skimming in
top-blown furnace shops is extended to apply to hot metal transfer and
skimming in bottom-blown furnace shops. The .provisions of Subpart Na,
§60.145a, allow the owner or operator of an affected facility to
suspend shop operations not subject to Subpart Na during compliance
testing. These provisions are a means of avoiding interference from
bottom-blown furnace emissions during compliance testing of hot metal
transfer and skimming operations. By similar reasoning, the proposed
concentration and opacity standards for secondary emission collection
devices in bottom-blown furnace shops also are retained.
2.5 VISIBLE EMISSION STANDARDS
2.5.1 Comment: (IV-D-3, IV-D-4) Two commenters opposed a provision
of the proposed standards [at §60.144a(b)(3)] that changes the way
Method 9 visible emission data from BOPF shops are analyzed. The
commenters noted that Method 9 requires an opacity value to consist of
the average of 24 consecutive visible emission observations taken at
15-second intervals and that the proposed standards alter this
requirement to produce an opacity value based on an average of 12
consecutive visible emission observations.
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Both commenters contended that the public was not afforded suffi-
cient opportunity to comment on the proposed changes. One commenter
concluded that the changes constitute ad hoc rulemaking and noted that
such procedures have been invalidated by Conner Hanna Coke Corp. v.
Costle, 464 F. Supp. 1295 (W.D.N.Y. 1979). The commenter believes
that "The 'Conner Hanna1 Court decision clearly demonstrates that the
test method used to evaluate compliance with a regulation is as impor-
tant as the regulation itself. Merely specifying the test method is
not enough when the accuracy and precision of the method are unknown
in the prescribed application."
The commenters also believe that the proposed 3-minute average
contradicts previously articulated policy about how Method 9 should be
used. In support of this, one commenter noted that "In previous
instances, EPA has suggested that there is no known basis for altering
the procedures and methodology established under Method 9. For example,
on November 24, 1982, while reconsidering the Illinois State implemen-
tation plan (SIP), the Administrator stated:
' ' •
'There is no means, using Method 9, to account for plumes,
less than 6 minutes in duration (noncontiguous). There is
also no means, using the averaging techniques of Method 9,
to account for exemption periods other than 6 minutes or for
aggregation of any duration. (47 FR 5300, 5302).'"
The second commenter noted that "In the past, EPA has recognized
that [Method 9] cannot be used for intermittent non-stack sources."
Response: Examining first the question of whether the public has
had opportunity to comment on the proposed changes, we conclude that
both the general public and steelmaking facilities with BOPF's have
had ample opportunity to participate in and comment on the proposed
changes. Prior to proposal, representatives of public interest groups
and steel companies were provided several opportunities to comment on
the 3-minute average. For example, the 3-minute average was discussed
at the National Air Pollution Control Techniques Advisory Committee
(NAPCTAC) meetings of December 2-3, 1980, and September 22-23, 1981
(II-C-24, II-E-23). The 3-minute average was also discussed at two
meetings held with representatives of the American Iron and Steel
Institute (AISI) November 12, 1980 (II-E-15), and September 17, 1981
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(II-E-25). Review drafts were specifically provided to AISI for
distribution to member companies September 4, 1981 (II-C-40), and
November 12, 1981 (II-C-42). In no case were written comments provided
by industry representatives or other interested parties prior to
proposal. At proposal, the preamble to the regulations discussed
testing and data reduction procedures used to establish the visible
emission standards and the procedures that would be followed to deter-
mine compliance (48 FR 2662). Comments received on these procedures
are being taken into account in this rulemaking.
In addition to the information provided in the forums noted
above, an analysis of the effects of the proposed changes on the
scientific reliability of Method 9 was included in the docket that
accompanied the proposed rule (II-B-92). The information in this
analysis demonstrates that the precision and accuracy of the proposed
changes to the Method 9 data reduction procedure for visible emission
observations of BOPF's are equivalent to the precision and accuracy in
the current Method. (This analysis is discussed in detail in the
response to comment 2.5-2.) Moreover, no new data or information on
the visible emission standards that contradicts the findings of our
analysis was included with the public comments. Therefore, the public
has been provided sufficient opportunity to comment on the proposed
performance testing and data analysis procedures.
We note that in citing the Illinois SIP reconsideration, the
commenter suggested that statements about the use of Method 9 in its
present form should limit how the Method might be modified. This
suggestion, however, is without merit. Rather, the validity of modifi-
cations to standards and test methods (and the relationship between
these) set forth in 40 CFR 60 must be evaluated and must be supported
on their own merits.
As to the question of whether Reference Method 9 can be used for
intermittent nonstack sources, it should be noted that since its
promulgation December 23, 1971 (36 FR 24895), Method 9 has been amended
to observe visible emissions from both control device exhaust stacks
and nonstack sources (39 FR 39872, November 12, 1974). (See, for
example, Subparts AA and BB.) Indeed, the Method, at paragraph 2.1,
2-24
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specifically includes procedures to be used in determining visible
emissions from nonstack sources such as roof monitors. Often, both
control devices and nonstack sources such as roof monitors intermittently
emit plumes of varying opacity; i.e., visible emissions vary with
process or control device operation and are observed only during part
of the time the emission source is operating. Reference Method 9 can
be applied accurately to both categories of emission points by following
the procedures of paragraph 2.1 and by recording visible emission
observations of zero percent opacity when no visible emissions are
evident.
The passage from Method 9 cited by the Court in Conner Hanna does
not state that Method 9 is inappropriate for characterizing visible
emissions from all points of intermittent emissions:
EPA recognizes that certain types of opacity violations that
are intermittent in nature require a different approach in
applying the opacity standards. ... (39 FR 39873)
The passage cited by the Court indicates that Method 9 (with the
6-minute averaging technique) may hot characterize the performance of
capture or control technologies adequately in certain cases. This can
be illustrated by the hypothetical example of a source that exhibits
zero opacity for 23 out of 24 readings and 25 percent on the 24th
reading. On a 6-minute average basis, the opacity would be calculated
as 1 percent. On a 15-second basis, opacity would simply be 23 periods
of zero and 1 period of 25 percent. It is obvious that this latter
method of presenting the visible emission data is much more descriptive
of the emission characteristics in this case than is the 6-minute
1-percent opacity average. In the broader context, this hypothetical
example illustrates how shorter averaging periods more accurately
reflect the character of short-duration plumes. (It also shows how
general opacity standards that are commonly used in SIP's do not
account for plumes of short duration.) For this reason, a shorter
averaging time and a higher numerical visible emission standard were
proposed for BOPF's. A 6-minute averaging period could have been
selected to analyze BOPF visible emission data. If this option had
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been selected and implemented, the numerical level of the standard
would have been about one-half the numerical level proposed in conjunc-
tion with the 3-minute averaging period. However, BOPF secondary
emissions are typically of short duration, and a 3-minute averaging
period more closely characterizes the performance of the capture
systems used to control the emissions than a 6-minute averaging period.
Finally, it is agreed that the test method used to determine
compliance with a standard is very important in establishing the
stringency or effect of a standard. For this reason, the basis for
the standard, including not only the data base but also both the test
method used to develop the data base and the test method used for
compliance, must be considered in establishing a standard. This is
discussed further in response to comment 2.5.2.
In conclusion, it is noteworthy that this proposed rulemaking
does not affect Method 9 data reduction procedures or application of
Method 9 to all sources regulated in 40 CFR Part 60. Rather, it only
establishes procedures for BOPF's that commence construction, modifica-
tion, or reconstruction after January 20, 1983. Use of a 3-min,ute
average was proposed in paragraph 2.5, "lest Methods and Procedures"
in Subpart Na, rather than as amendments to Reference Method 9. Ihis
was done because 3-minute average opacity values are considered appro-
priate for and are intended to be applicable only for BOPF shop emissions.
In this way, Method 9 as it applies to other sources is not affected
by this ralemaking. Ihis approach is consistent with the intended use
of the test methods in Appendix A (40 CFR Part 60). Ihe intent is
detailed in the introduction to Appendix A, which states, in part:
Within each standard of performance, a section titled 'lest
Methods and Procedures' is provided to (1) identify the test
methods applicable to the facility subject to the respective
standard and (2) identify any special instructions or condi-
tions to be followed when applying a method to the respective
facility. Such instructions . . . are to be used either in
addition to, or as a substitute for, procedures in a reference
method.
Iherefore, it is appropriate to alter—after analysis and public
comment—the data reduction procedures for BOPF visible emission
observations within the provisions of Subpart Na.
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2:5.2 Comment: (IV-D-1, IV-D-3, IV-D-4, and IV-D-5) Several commenters
questioned the scientific reliability of the proposed 3-minute averages
for Reference Method 9 opacity computations of visible emissions from
BOPF's. The commenters contended that the modified averaging procedure
will produce average opacity values that are less accurate and more
subject to error than the 6-minute opacity values. The commenters
stated that the proposed secondary standards require the improper use
of Reference Method 9 for observing roof monitor visible emissions
because the method was promulgated originally for observation of
stacks, with specified data reduction procedures for 6-minute averages.
The commenters stated that quantitative conclusions regarding the
accuracy of the method were valid only for emissions from stacks. One
commenter also maintained that modifications to Method 9 should be
thoroughly evaluated to determine the accuracy and precision of any
deviations and recommended that Method 9, unmodified, be used for the
proposed regulation or that the proposed roof monitor opacity standard
be deleted until an appropriate method is developed. One commenter
further asserted that .the proposed changes are not supported by any
analysis of the effects of the changes on the scientific reliability
of Method 9.
Response: We share the commenters1 concerns that knowledge of
the precision and accuracy of a test method—and consideration of
these factors for the public record—is important in developing and
enforcing standards. Prior to responding to these concerns, it is
appropriate to review the general procedure followed to establish a
standard of performance and to understand the role of the test method
to establish and determine compliance with the standard. Typically, a
standard is expressed as a numerical emission limit that quantifies
the performance of BDT for emission control. A data base is gathered
to establish an emission limit that is achievable for the emission
source being regulated. The data base is obtained with either an
existing or new test method that has been devised for the pollutant
and source being regulated. If the method used to develop the data
base differs from the method that would be used to determine compliance,
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the mathematical relationship between these methods must be known. In
either case, the test method is proposed and promulgated according to
the procedures outlined in §307(d) of the Clean Air Act as amended and
is found either in Appendix A or in the subparts of 40 CFR Part 60.
In the proposed and final standards, the accuracy and precision of the
test method are documented and considered carefully.
When the visible emission standards were developed for BOPF's, a
large number of visible emission observations were gathered according
to the procedures of Reference Method 9. These data, which consist of
more than 100 hours of observations, indicate that plumes from the
roof monitors of BOPF shops are of short duration and that the perform-
ance of BDT for controlling these emissions is best characterized with
an average opacity value based on a shorter, 3-minute averaging period
instead of the 6-minute averaging period specified in the data reduction
procedures contained in paragraph 2.5 of the reference method.
Therefore, a visible emission standard was proposed that would be
based on the BOPF visible emission data base and on average opacity
values calculated from 12 consecutive 15-second visible emission
observations recorded by following the procedures of Reference Method 9.
The proposed and final performance test procedures are also based on
observing and recording visible emissions with Reference Method 9 and
on calculating a 3-minute opacity average from the visible emission
data.
Before 3-minute rather than 6-minute averages were proposed, the
question of whether 3-minute averages are less accurate or precise
than 6-minute averages was addressed. (Note that the accuracy and
precision of 6-minute averages have been established and are not an
issue here.) This involved analyzing and comparing the frequency of
occurrence of differences between Method 9 observations (observer
mean) and mean values calculated from transmissometer readings (instru-
ment mean) for both 3- and 6-minute averaging periods. This analysis,
which was included in the docket prior to proposal (II-B-92), is based
on a July 1976 report that also was included in the docket prior to
proposal (II-A-22). The results of this analysis are summarized in
Table 2-3.
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TABLE 2-3. OBSERVER ERROR FOR 3-MINUTE AND 6-MINUTE OPACITY AVERAGING9
(percent of total observations)
Source
Smoke generator,
3-minute average
Opacity range , %
0-5 5-10 10-15
36.5 1.9 0.0
6-minute average
Opacity range, %
0-5 5-10 10 -
35.3 0.8 0.0
15
black smoke
Smoke generator, 36.0 8.0 0.3
white smoke
Riverbend Steam 41.7 5.2 1.0
Station
31.8
43.8
7.1
4.2
0.0
1.0
Observer error is defined as deviation of observed average opacity from
reference (transmissometer) average opacity.
SOURCE: "Examining the Properties of Qualified Observer Opacity Readings
Averaged over Intervals of Less than Six Minutes," Research
Triangle Institute, July 1976 (II-A-22).
The results are reported as the percentage of the total number of
measurements that fall within a particular range of observer error.
For example, 36.5 percent of the total number of 3-minute averages
calculated for the smoke generator black smoke had an observer error
of between 0 and 5 percent opacity. Note that only positive errors
are reported in the table. Examination of this table reveals that the
distribution of errors for 3-minute averaging is about the same as for
6-minute averaging (e.g., for generator black smoke, 36.5 percent of
the calculated 3-minute averages had an observer error of 0 to 5 percent
opacity as compared to 35.3 percent of the calculated 6-minute averages).
Thus, the average opacities calculated on a 3-minute basis are no more
subject to error than the average opacities calculated on a 6-minute
basis.
With regard to the applicability of Method 9 to plumes from both
stacks and roof monitors, a review of opacity theory demonstrates that
quantitative conclusions about the accuracy and precision are equally
valid for each.
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The major factors influencing plume opacity are: particle charac-
teristics (particle size distribution, particle density, and refractive
index), particulate concentration, the background against which the
emissions are viewed, the observer's position relative to the sun, and
the light path length through the emission plume. Particle character-
istics and particulate concentration are determined by the process
operation and the emission control technology. In the steel industry,
plumes are released at elevated points such as stacks and roof monitors.
As a result, the background for reading the opacity of visible emissions
is the same for both types of sources, generally consisting of sky,
horizon, or other structures. Thus, the ability to read opacity of
visible emissions from roof monitors compared to the ability to read
visible emissions from stacks is not influenced by background.
While the geometry of stacks and roof monitors does differ,
Reference Method 9 explicitly accounts for opacity readings from roof
monitors. Stacks are generally circular and, as a result, the path
length through the plume is essentially the same in all directions.
Roof monitors tend to be rectangular with a long and short dimension.
The light path length through the plume is different depending on
whether the observer sights along the long dimension or the short
dimension. When the opacity of visible emissions from roof monitors
is read, paragraph 2.1 of Reference Method 9 specifically requires
that observations be taken approximately perpendicular to the long
dimension of the roof monitor (i.e., across the short dimension of the
plume), which ensures that observed opacity is minimized. When the
visible emission standards for BOPF's were developed, visible emission
observations were taken from existing furnace shops with typical roof
monitor designs. We have no data or other information that indicates
that future roof monitor designs would be modified to cause plume path
length, and thus observed opacity, to increase. Thus, the effect of
path length on opacity was taken into account during development of
the standards, and paragraph 2.1 of Reference Method 9 ensures that
compliance with the standards is determined by reading plumes across
the shorter path length.
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The position of the visible emission observer with respect to the
sun and the plume does affect perceived opacity due to the light-
scattering effects of plumes. However, this light-scattering inter-
ference is nullified as the observer is positioned with his back to
the sun as described in paragraph 2.1 of the Reference Method. This
paragraph provides explicit instructions that position the observer
with respect to both stacks and rectangular openings such as roof
monitors. Thus, the effect of position on opacity is taken into
account during development of visible emission standards.
The ability to read the opacity of visible emissions, therefore,
does not depend on whether these emissions are released from stacks or
roof monitors. Reference Method 9 is as applicable to plumes from
roof monitors as it is to plumes from stacks.
After proposal of Subpart Na, statistical analyses of visible
emission observations recently taken from roof monitors and stacks
were performed to validate this conclusion further. These analyses
are summarized in a memorandum entitled "Opacity Error for Different
Averaging Times" -(IV-B-6), which reports the results of statistical
analyses of visible emissions from fugitive emission' sources. The
fugitive emission data were obtained mostly from iron and steel sources
with BOPF shops and roof monitors being major contributors to the data
base.
One statistical analysis examined the precision of observations
of the opacity of a fugitive emission plume made simultaneously by two
visible emission observers. For average opacity values calculated
with a 6-minute averaging period, the standard deviation was 2.1
percent opacity with 93 percent of the runs having a difference between
observer readings less than or equal to 7.5 percent opacity. For
average opacity values calculated with a 3-minute averaging period,
the standard deviation was essentially the same--2.4 percent opacity
with 92 percent of the runs having a difference between observer
readings less than or equal to 7.5 percent opacity. This analysis of
visible emission observations of fugitive emissions therefore supports
the conclusion that between-observer precision is the same for average
opacity values calculated with 3- and 6-minute averaging periods.
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Table 2-4, taken from the same memorandum, can be used to compare
the between-observer precision of fugitive emission observations with
that of stack emission observations. The stack standard deviations
range from 4.3 to 9.8 percent for 3- and 6-minute averages compared to
the 2.1 percent and 2.4 percent reported above for the fugitive sources.
Thus, it is concluded that the variability between observers in reading
opacity from roof monitors is similar to that between observers reading
opacity from stacks.
TABLE 2-4. STANDARD DEVIATION OF ERROR (BETWEEN-
OBSERVER PRECISION) FOR DIFFERENT AVERAGING TIMES
(BY LOCATION AND SMOKE COLOR)
Error standard deviation (percent opacity)
Averagi ng
time
6 minutes
3 minutes'
Riverbend3
White
5.0
5.1
Florida lb
Black
6.7
6.8
White
6.5
6:8
Florida 2C
Black
9.3
9.8
White
6.4
7.0
RTPd
Black
4.3
4.7
White
5.9
6.2
Fossil-fuel-fired electric utility.
Smoke generator—continuous plume.
°Smoke generator—slowly changing plume.
Smoke generator—rapidly changing plume.
SOURCE: "Memorandum, P. Piserchia and J. Crowder, Research Triangle
Institute, to K. Foster and B. Burton, EPA:SSCD, September 8,
1983, Opacity Error for Different Averaging Times. (IV-B-6).
In summary then, analyses performed both before and after proposal
of the visible emission standard demonstrate the scientific reliability
of the 3-minute averageing technique. These analyses show that average
opacities calculated on a 3-minute basis are no more subject to error
than opacities calculated on a 6-minute basis. Therefore, the 3-minute
averaging technique is retained in the final standards.
2.5.3 Comment: (IV-D-1 and IV-D-4) Two commenters recommended the
inclusion of alternative mass emission limits in the proposed standard
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for roof monitors as allowed under 40 CFR 60.ll(e). One commenter
stated that a recently published procedure would allow measurement of
mass particulate emissions from roof monitors. It was recommended
that if process fugitive emissions fail to meet visible emission
limits, the source should be allowed, as an alternative, to comply
with measured mass emission rate estimates on which the visible emission
limit is based. However, the second commenter pointed out that the
option available under 40 CFR 60.11(e) is not available to BOPF shop
roof emissions because the standards do not contain mass emission
limits or a means for allowing the exemption.
This commenter believes that the need for such an exemption is
recognized by the EPA:
In the preamble of the proposal (p. 2666), EPA states that "Because
of wide differences in operating procedures, such as the length
of the steel production cycle, control technologies, vessel
capacities, and other operating parameters between BOPF shops, a
single emission rate that is uniformly applicable to the industry
or a specific type of vessel is not practicable." This same
difference applies to visible emissions and highlights the need
for alternative limits. .
Response: Measurements of mass emission rates from roof monitors
have been performed and reported in published technical literature on
several occasions. However, research to verify the accuracy and
precision of a test method based on this concept would be necessary
and costly. In contrast, as discussed in the response to comment
2.5.2, the use of Reference Method 9 to determine the opacity of
fugitive particulate matter emissions is accurate, reliable, and
relatively simple for ensuring not only the installation of BDT, but
also the proper operation and maintenance of BDT.
Turning now to the comment about alternative opacity provisions
of §60.11(e), the commenter is correct in noting that they do not
apply to visible emission standards for BOPF's. In this instance and
similar instances in other NSPS's, the standard of performance is
expressed in terms of opacity without an accompanying mass emission
standard. In these instances, the visible emission standard is adequate
to ensure that BDT is installed and properly operated and maintained.
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Section 60.11(e) applies to, and was intended to cover, situations
where both mass and visible emission standards are needed to charac-
terize the performance of BDT. In these situations, the mass emission
standards are, in effect, the primary standards used to quantify the
performance of BDT. The visible emission standards in these situations
are established to provide a timely and inexpensive procedure to
ensure that BDT is properly operated and maintained. Thus, in these
situations, visible emission standards are established at a numerical
level that is no more stringent than their associated mass emission
standards. Section 60.11(e) was established to achieve this intent by
providing a means through which a source may obtain a higher ad hoc
visible emission standard when the source demonstrates compliance with
the mass emission standard but is not in compliance with the visible
emission standard.
In summary, the visible emission standards for BOPF's are adequate
to reflect performance of BDT. Thus, for these standards—as with
other single performance standards (e.g., S02, NO )--there is no basis
}\
for allowing case-byrcase relaxations of the standards.
2.5.4 Comment: (IV-D-2) One commenter suggested that visible emission
data presented under "Emission Testing" for Bethlehem Steel Corporation,
Kaiser Steel Company, and J&L Steel Corporation may be misleadingly
high because of the contributions from ancillary operations.
Response: The purpose of the roof monitor visible emissions
standard is to ensure proper operation and maintenance of devices used
to capture fugitive emissions from charging, tapping, hot metal transfer,
hot metal skimming, and furnace operations. The data collected in
support of the proposed standards were based on combined emissions
escaping capture from the above sources and ancillary operations such
as ladle repair, skull burning, and teeming that occurred randomly
during the test program. However, the contribution of these ancillary
operation emissions to observed roof monitor opacity was minimal. The
reason that visible emissions from nonaffected facilities were included
is that it is difficult during normal shop operations to isolate the
affected facilities from nonaffected facilities. However, the intention
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is not to regulate existing facilities by_this means. This is evident
from the provisions of §60.145a of the final rules, which permit shop
operations not subject to Subpart Na to be suspended during compliance
testing (for both mass and visible emissions).
As noted in the proposed rulemaking (p. 2668), Method 9 readings
were taken for top-blown furnaces during the operation of these unaffected
facilities. Because the visible emission standard is based on these
data, compliance can be demonstrated while these operations continue.
This permits compliance testing without the disruption of normal shop
operations. However, the regulation does permit the shutdown of
unaffected operations so that compliance can be based only on emissions
from affected operations.
2.6 EMISSION TESTING AND MONITORING
2.6.1 Comment: (IV-D-4) One commenter stated that the reduced
testing time for top-blown BOPF primary emissions is a strong disin-
centive for owners to modernize existing top-blown BOPF equipment
because, then, the existing gas-cleaning device may also have to be
improved. The commenter also noted that effects of primary gas-cleaning
system operating parameter modification on secondary emissions were
not addressed. The commenter recommended that the primary emission
standard for top-blown BOPF's specified in §60.144(b)(2) be limited to
newly constructed furnaces and that the effects of primary gas-cleaning
system changes on secondary emissions be addressed.
Response: The intent is not to discourage the modernization of
existing BOPF equipment. Modernization taking the form of modifications
not increasing total particulate emissions and not exceeding the
reconstruction fixed capital cost limitation of 40 CFR 60.15 may be
made without subjecting the facility to the requirements of §60.144(b)(2);
40 CFR 60.14(e) also lists some physical or operational changes that
are not considered modifications, irrespective of any changes in the
emission rates. Beyond this, however, the intent of Section 111 is to
require new, modified, or reconstructed facilities to apply BDT.
The commenter1s assertion that changes in the primary control
system operating parameters may affect secondary emissions is correct.
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Fugitive emissions from furnace operations, not captured by the primary
hood, may increase or decrease depending on the changes in primary
control device operating parameters. However, the modification or
reconstruction that makes the facility subject to §60.144(b)(2) also
causes the facility to be subject to Subpart Na for control of secon-
dary emissions. Compliance with both provisions of the regulation may
be achieved in a number of ways, some of which do not require changes
in the primary system operating parameters that would adversely affect
secondary furnace emissions. It is up to the owner or operator of the
facility to select the most economical means of achieving compliance
for the particular situation.
2.6.2 Comment: (IV-D-2) One commenter cited §60.144(b)(l) of the
primary standard, which states, "A cycle shall start at the beginning
of either the scrap preheat or the oxygen blow and shall terminate
immediately prior to tapping." The commenter believes a contradiction
exists between this section and a statement under "Review of the
Primary Standard" that says reblows would not be considered part of
the primary oxygen blow under the proposed revision. He also indicated
that the minimum sample volume of 32 dscf for §§60.144(b)(l) and (2)
proposed for the primary standard (Subpart N) is too small and recom-
mended a minimum volume of 60 dscf.
Response: The paragraph on page 2669 of the Federal Register
proposal notice referring to reblows not being considered part of the
primary oxygen blow refers to the proposed revisions to existing
Subpart N for primary emissions from BOPF's. It is the intent that
the revisions discussed under "Review of the Primary Standard," which
require mass testing only during the primary blow, apply only to
facilities that commence construction, modifications, or reconstruction
after January 20, 1983, as stated in §60.144(b)(2). Affected facilities
commencing construction, modifications, or reconstruction on or before
January 20, 1983, must sample in accordance with the provisions as
described in §60.144(b)(l), which require testing during the steel
production cycle, including reblows. Therefore, no contradiction
exists.
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As a result of a review of the proposed minimum sample volume
specified in §60.144(b)(l) and 60.144(b)(2) of the primary standard,
the required minimum sample volume has been increased from 0.9 dscm
(32 dscf) to 1.5 dscm (53 dscf). The minimum sample volume was revised
to provide an allowance for a 50-mg particulate catch on the sampling
train filter, taking into account collection of particulate matter in
:the nozzle and on the walls of the sampling probe. This increase in
minimum sample volume is needed to maintain test precision. The
minimum sample volume was not increased to 60 dscf because 1.5 dscm
(53 dscf) was judged to be sufficient to provide the 50-mg particulate
catch without unnecessarily increasing the test length and the cost of
performance testing. These revised sample volume requirements are
applicable to facilities constructed, modified, or reconstructed after
January 20, 1983, and to existing affected facilities subject to
Subpart N (i.e., those BOPF's constructed, modified, or reconstructed
after June 11, 1973, but on or before January 20, 1983). As proposed,
shorter sampling times and smaller sample volumes would be allowed,
subject to approval by the Administrator, when necessitated by process
variables or other factors,
2.6.3 Comment: (IV-D-2) One commenter suggested that performance
tests for secondary mass emission limitations should be performed only
during portions of the production cycle that include a specific secon-
dary emission activity;, e.g., hot metal charging. The commenter
stated that inclusion of other low-emitting portions of the production
cycle, such as scrap charge, dilutes the sample. To accommodate his
suggested change, the commenter recommended the use of a high-volume
Method 5 sampler to compensate for the difficulty of obtaining sufficient
sample from operations of such short durations. If high-volume Method 5
samplers are not required, the commenter recommended that the minimum
sampling volume be increased from 80 dscf to 160 dscf to minimize
sample recovery errors and to maintain reasonable precision from test
to test.
Response: The possibility of sampling the secondary emission
controls system only during the occurrence of high-emission operations,
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such as hot metal charging, tapping, and hot metal transfer, was con-
sidered during the development of the proposed standard. However,
most of the test data available on particulate concentrations at the
outlet from fabric filters serving secondary emission sources were not
obtained in this manner, but rather by sampling over both high- and
low-emitting portions of the cycle.
Because the secondary emission operations of hot metal transfer
and skimming may occur independently of furnace operations and be
ducted to the same secondary control device, limiting emission testing
to just the typically high-emitting secondary operations unnecessarily
complicates the performance tests. For both of these reasons, sampling
was proposed over the entire steel production cycle. Because it is
believed that sampling over the entire steel production cycle is
appropriate, no further consideration was given to the use of high-
volume Method 5 sampling trains. However, the minimum required sampling
volume for each sample run has been increased from 2.27 dscm (80 dscf)
to 5.67 dscm (200 dscf). This change has been made to ensure that
adequate particulate matter is sampled to maintain test precision.- A
new provision was also added to the final rules, which allows shorter
sampling times and lower sample volumes when necessitated by process
variables or other factors, subject to approval by the Administrator.
In regard to Method 5, it should be recognized that a new Method
5d was proposed recently for use with positive-pressure baghouses
(48 FR 37354, August 17, 1983). Although the final standards cannot
require the use of Method 5d until the Method is promulgated, owners
and operators of positive-pressure baghouses may choose to take advantage
of §60.13(i) of the NSPS General Provisions, which allows the use of
alternative test methods.
2.6.4 Comment: (IV-D-2) One commenter stated that if it is agreed
that emissions from the secondary control device should be sampled
only during high-emitting portions of the production cycle, EPA Refer-
ence Method 2 should be revised. The basis for this comment is that
velocity readings provided by noncontinuous sampling would not yield
accurate flow rate data. The commenter believes that accurate flow
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rate data, while not essential to the proposed concentration standard,
will be necessary to calculate emission rates for State or local
agency standards. The commenter also recommended a continuous flow
rate monitoring device to assist in determination of mass emission
rates.
Response: For the reasons stated in the response to the previous
comment, disagreement exists concerning the commenter1s view that
secondary emission sampling should be conducted only during high-emitting
portions of the steel production cycle. It is believed that velocity
readings obtained continuously during Method 5 sampling will provide
an adequate basis for estimating the mass emission rate from the
secondary control device over the entire production cycle. The proposed
regulation would not preclude State or local agencies from adopting
their own requirements for flow rate measurements needed to determine
compliance with their emission standards.
The monitoring provisions of §60.143a require the owner or operator
to install a monitoring device or devices to continually monitor and
record the various rates or levels of exhaust ventilation through each
duct,of the secondary emission control system for each phase of each
steel production cycle. The monitoring and recording of ventilation
rates or levels will ensure proper operation and maintenance of the
secondary emission capture system. Other revisions made to the monitor-
ing requirements since proposal are discussed in the response to
comment 2.7.3. The commenter's suggestion that the continuous flow
rate monitor can be used to determine volumetric flow rate during a
stack test and subsequent calculation of mass emission rate may be
useful to State or local agencies with mass emission rates rather than
concentration standards.
2.6.5 Comment: (IV-D-2) One commenter agreed that process monitoring
should be required during all compliance testing but believed a list
of process variables and control device variables that could affect
the results of a test should be included for use during testing.
Response: We agree that such a list would be helpful to monitor
the process and control device operations properly during performance
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testing. However, the variety of emission control system designs and
the variation of process equipment and operations in plants make the
development of a universally applicable and comprehensive list a
difficult task. Furthermore, the use of a universally applicable list
suggests that information may be requested from a plant that will not
be useful in its specific case, therefore increasing the associated
testing burden for the owner or operator of this facility. For these
reasons, it was decided not to publish a list of recommended or required
process and control device variables to be monitored.
2.6.6 Comment: (IV-D-2) One commenter suggested that the steel
production cycle should not be used to characterize BOPF secondary
visible emissions from hot metal charging, tapping, hot metal transfer,
and skimming. The commenter suggested using those individual operations
as the basis for characterization. He stated that this would provide
more realistic data on the effectiveness of controls for these specific
operations, rather than the visible emission effects of unregulated
.ancillary operations.
Response: In the initial analyses of roof monitor visible emission
test data, the characterization of the data on the individual operation
basis was considered, as suggested by the commenters. Other approaches
to characterizing the data were considered as well. Use of the steel
production cycle as the basis for characterization was selected for
two reasons. One reason was that the secondary emission control
systems may be used to control emissions from several secondary sources,
especially in newer plants when closed hood primary control systems
are selected. With such a secondary system, several secondary process
operations may occur simultaneously, sometimes related to two furnace
vessels, hampering the effort to obtain visible emission data for
separate secondary emission processes. The second reason was that
roof monitor visible emissions lag behind the actual process operation
that generates them. Determining when to cease observations because
all emissions from the particular secondary operations have left the
roof monitor is difficult. The fact that five potential secondary
emission sources exist, including puffing emissions escaping the
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primary hood, compounds this problem. Using the steel production
cycle to characterize these secondary emissions minimizes or eliminates
the above difficulties.
The commenter's point about the effect of unregulated ancillary
operations on observed secondary visible emissons from regulated
sources is addressed in the response to comment 2.5.4.
2.7 EQUIPMENT, DESIGN, AND OPERATING SPECIFICATIONS
2.7.1 Comment: (IV-D-2) One commenter agreed with the preamble
(p. 2661) that the use of operating practices conducive to lesser fume
generation is very important in reducing secondary emissions. These
practices include the use of clean scrap, slow pouring techniques,
careful positioning of the hot metal ladle, and proper furnace tilt
angle. However, this commenter questioned why these practices are not
required by the proposed standards to ensure successful secondary
emissions control.
Response: Section lll(h)(l) of the Clean Air Act provides that,
"If in the judgment of the Administrator, it is not feasible to prescribe
or enforce a standard of performance., he may instead promulgate a
design, equipment, work practice, or operational standard, or combina-
tion thereof, which reflects the best technological system of continuous
emission reduction that (considering the cost of achieving such emission
reduction and any nonair quality health and environmental impact and
energy requirements) the Administrator determines has been adequately
demonstrated . . . ."
The phrase "not feasible to prescribe or enforce" means "any
situation in which the Administrator determines that (A) a pollutant
or pollutants cannot be emitted through a conveyance designed and
constructed to emit or capture such pollutant, or that any requirement
for, or use of, such a conveyance would be inconsistent with any
Federal, State, or local law, or (B) the application of measurement
methodology to a particular class of sources is not practicable due to
technological or economic limitations" [lll(h)(l)-(2)].
As explained at 48 FR 2658, the proposed standards of performance
were based on BDT for BOPF's and hot metal transfer and skimming
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stations. For secondary emissions from a top-blown furnace, the open
hood primary emission control system that also controls secondary
emissions was selected as BDT. For hot metal transfer and skimming
stations, local hooding ducted to a baghouse was selected as BDT.
For each affected facility, particulate matter can be captured
via the primary or secondary hood. Measurement methodology (Reference
Method 5) is available to ascertain the concentration of particulate
matter at the outlet of the collection device. Because it is feasible
to prescribe and enforce a standard of performance for this source
category, an emission limit format was selected for BOPF collection
devices in lieu of specifying work practice or equipment, design, and
operational requirements. Opacity limits are also included as a
supplement to the concentration limits because visible emissions act
as a good indicator of the secondary emission control system performance
and as an indicator of proper operation and maintenance of the device.
While it is true that the application of these practices is
conducive to lesser fume generation, the total impact of these practices
on resulting emission reductions for all types of BOPF's is not clear.
Many of the work practices were observed at the J&L/Aliquippa and
Bethlehem/Bethlehem shops, both of which use a primary hood to control
secondary emissions from top-blown furnaces. Application of these
practices appeared beneficial in secondary emission control for these
systems. However, it is not clear that these practices resulted in a
significant impact on secondary emission control at the top-blown/closed
hood system at Kaiser/Fontana.
Because the impact of these practices on the secondary control
system for each type of furnace or control system cannot be fully
quantified in terms of the resulting emission reductions, the standard
does not require their application to supplement the secondary emission
control afforded by the application of BDT. Consequently, the imple-
mentation of these practices may not be necessary to achieve the
emission limits, whether concentration or opacity. This should not
imply that any good operating practices consistent with minimizing
emissions should not be applied to the extent practicable, as required
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under §60.11(d). For example, these practices may have a significant
impact for open hood primary systems used to control secondary emissions;
and although the degree of impact on other types of systems is unclear,
the application of these practices is encouraged for each BOPF facility,
whether or not subject to the standards of performance.
2.7.2 Comment: (IV-D-2) One commenter agreed with the preamble
(p. 2661) that a separate capture and collection system is necessary
for a closed hood primary system controlling secondary emissions from
the furnace in order for the closed hood system to achieve a control
efficiency similar to that of the open hood system. The proposed
capture system for closed hood systems consists of a furnace enclosure
evacuated by auxiliary hooding ducted to a high-efficiency collection
device, such as a baghouse. The commenter recommended that minimum
guidelines for hood size and extensions and for fan evacuation capacity
be established, based on data from existing systems that meet the
proposed standards.
Response: As explained in the response to comment 2.7.1, a
numerical emission limit was selected as the format of the standard in
lieu of work practices or equipment, design, and operating specifications.
This approach offers certain advantages compared to equipment and
design specifications (e.g., hood size and fan evacuation capacity)
because any equipment capable of meeting the emission limits can be
used to achieve compliance. In addition, the operating parameters of
the equipment can be tailored to meet the needs of the particular
facility. Designs and operating specifications for secondary emission
control systems are expected to vary according to the type of vessel
and the differences in operating parameters and procedures among
existing shops. For example, shop structure could influence the size
or location of auxiliary hooding. Also, fan evacuation capacity
specifications may vary, depending on the amount of dilution air
entrained into the system. Because of the differences in design and
operating parameters among BOPF shops, the establishment of equipment
and design specifications based on data from existing shops could
limit the flexibility needed by BOPF owners and operators, particularly
2-43
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in retrofit situations. For these reasons, equipment, design, or
operational requirements are not included in the promulgated standards.
2.7.3 Comment: (IV-D-2) This commenter agreed that the exhaust
ventilation rate is an important monitoring parameter to determine if
the secondary capture system is operating effectively. However, he
suggested that a baghouse pressure drop monitoring device also be
considered. The addition of this device would ensure that the baghouse
is being properly cleaned and is working at the design air-to-cloth
ratio for the effective removal of captured emissions.
Response: As explained at 48 FR 2667, Clean Air Act requirements
relating to the operation and maintenance of a source are generally
included in new source standards of performance in the form of monitor-
ing requirements. The operating parameters selected for monitoring
requirements should be related to the performance of the emission
control system and should be parameters that can be monitored without
an unreasonable burden on the owner or operator.
Both exhaust ventilation rate and baghouse pressure drop are
considered good indicators of the effectiveness of the secondary
emission control system. However, a drop in exhaust ventilation rate
is the better indicator of the control system performance, while
baghouse pressure drop is the better indicator of the performance of
the collection device. Exhaust ventilation rate or level was selected
as the monitoring parameter because it provides a better indicator of
overall secondary emission control system performance.
In regard to the secondary emission collection device, however,
the opacity limit of 5 percent serves to supplement the monitoring
requirement for exhaust ventilation rate or level. The opacity limit
is also a good indicator of the effectiveness of the secondary emission
collection device because degredation in baghouse performance will
result in increased opacity. The monitoring of exhaust ventilation
rate or level, coupled with the opacity limit, would provide a good
indication of both the control system performance and the effective-
ness of the collection device. Consequently, it appears unnecessary
to require the continual monitoring and recording of both exhaust
2-44
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ventilation rate and baghouse pressure drop. Also, most new baghouse
systems are equipped with pressure drop indicators. Although these
indicators do not provide a continual record, they are considered
sufficient to signal potential operating or maintenance needs for a
baghouse before increased opacity results.
Review of the requirement for monitoring of exhaust ventilation
rate as the secondary emissions monitoring parameter resulted in an
examination of new monitoring systems for application to BOPF's. New,
inexpensive systems are now available that allow the owner or operator
to measure and record changes in the level of exhaust ventilation
through the system. The cost of the entire monitoring and recording
system is estimated at less than $2,000, with backpurge, for each
installation. For this reason, the final regulation was modified to
require the monitoring and recording of the various exhaust rates or
the monitoring and recording of the exhaust levels through each duct
of the system.
The compliance provisions were also expanded in the final rules
to require that during compliance testing of a single furnace at a
shop that normally operates two furnaces with overlapping cycles, the
owner or operator must maintain an exhaust ventilation rate or level
in each duct of the secondary emission control system that is appropriate
for single-furnace operation. After the compliance test, the owner or
operator must maintain for each duct exhaust ventilation rates or
levels that are no lower than 90 percent of the values established
during the most recent compliance test. Monitoring records indicating
lower rates (or levels) through the ducts may indicate improper operation
or maintenance of the system. The owner or operator must also report,
on a semiannual basis, all measurements over any 3-hour period that
average more than 10 percent below the average levels maintained
during the most recent compliance test for determining compliance with
the mass standard for secondary emission collection devices. A similar
provision requiring semiannual reporting also was added to the final
standards for monitoring results of scrubber pressure drop. This
requirement would apply if a scrubber primary emission control device
were used to collect secondary emissions.
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Other revisions to the monitoring requirements since proposal
include the use of the term "continual" monitoring rather than "con-
tinuous" monitoring to avoid confusion with the type of continuous
monitoring system defined under §60.2 of NSPS General Provisions.
Also, a new provision was added to the final standards that requires
the owner or operator to place the monitoring device (or devices) at
capture points for the secondary emission control system; alternative
locations for the monitoring device(s) must be approved in advance by
the Administrator. The final standards also include a provision for
the use of -a strip chart recorder, the most common form of recordkeeping.
This provision would require that if a strip chart recorder is used,
it must be operated at a minimum chart speed of 3.8 cm/hr (1.5 in./hr).
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-450/3'-.R3-nngh
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Revised Standards for Basic Oxygen Process
Furnaces—Background Information for
Promulgated Standards
5. REPORT DATE
December 1985
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING'ORGANIZATION NAME AND ADDRESS
Environmental Protection Agency
Office of Air Quality Planning and Standards
Emission Standards and Engineering Division
, Research Triangle Park, North Carolina 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-3056
12. SPONSORING AGENCY NAME AND ADDRESS
:DAA for Air Quality Planning and Standards
Office of Air, Noise, and Radiation
United States Environmental Protection Agency
'Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/200/04
15. SUPPLEMENTARY NOTES
_A New Source Performance Standard for secondary emissions of
participate matter from basic oxygen process furnace (BOPF) steelmaking
shops is oeing promulgated under authority of Section 111 of the Clean
Air Act. This final action is applicable to.secondary emissions from
•;any top-blown BOPF arid to any hot metal transfer station or skimming '
:station used for a bottom-blown or top-blown BOPF, for which constructicn,
reconstruction, or modification commenced after January 20, 1983. The
purpose of the final standard is to minimize BOPF secondary particulate
.emissions to the level attainable with the best demonstrated technolocry
.Amendments to the existing BOPF primary standard (40 CFR 60 140
Subpart N) are also being promulgated. These amendments to Subpart N
.apply to primary emissions from BOPF's constructed, reconstructed, or
• reconstruct^.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Air Pollution
Pollution Control
Standards of Performance
Basic Oxygen Process Furnaces
Opacity
Particulates
Air Pollution Control
13 B
Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
65
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77) PREVIOUS EDITION IS-OBSOLETE
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