United States                Office of Air Quality-
Environmental Protection      Planning and Standards
Agency                      Research Triangle Park NC 27711

Air             ~~~
EPA-45O/3-82-O2Ob
August 1984   •

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                               EPA-450/3-82-020b
Electric Arc Furnaces and Argon-Oxygen
Decarburization Vessels In Steel  Plants-
Background Information for Promulgated
                  Standards
             Emission Standards and Engineering Division
             U.S. ENVIRONMENTAL PROTECTION AGENCY
                 Office of Air and Radiation
             Office of Air Quality Planning and Standards
             Research Triangle Park, North Carolina 27711

                    August 1984

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This report has been reviewed by the Emission Standards and Engineering Division of the Office of Air
Quality Planning and Standards, EPA, and approved for publication. Mention of trade names or
commercial products is not intended to constitute 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, N.C. 27711, or from the National Technical Information Services,
5285 Port Royal Road, Springfield, Virginia 22161.

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                       ENVIRONMENTAL  PROTECTION  AGENCY

                           Background Information
                                  and Final
                       Environmental  Impact  Statement
                        for Electric  Arc  Furnaces  and
           Argon-Oxygen Decarburization  Vessels in  Steel  Plants
                                Prepared  by:
     R. Farmer
Director, Emission Standards and Engineering Division
U. S. Environmental Protection Agency
Research Triangle Park, North Carolina  27711
/  (rate)
1.  The promulgated revised standards of performance continue to  limit
    particulate matter emissions from an electric arc furnace and argon-
    oxygen decarburization vessels.  The visible emission standard  is less
    than 3 percent from a control device, less than 6 percent from  the
    shop, and less than 10 percent from the dust-handling system.
 •   Section 111 of the Clean Air Act (42 U.S.C. 7411), as amended,  directs
    the Administrator to establish standards of performance for any category
    •of new stationary source of air pollution that "... causes or
    contributes significantly to air pollution which may reasonably be
    anticipated to endanger public health or welfare."  Stee.l plants are
    located in all areas of the nation.

2.  Copies of this document have been sent to the following Federal
    Departments:  Labor, Health and Human Services, Defense, Transporta-
    tion, Agriculture, Commerce, Interior, and Energy; the National Science
    Foundation; the Council on Environmental Quality; members of the State
    and Territorial Air Pollution Program Administrators; and Association
    of Local Air Pollution Control Officials; EPA Regional Administrators;
    and other interested parties.

3.  For additional information contact:
    Mr. C.  Douglas Bell                                               .
    Standards Development Branch (MD-13)
    U. S. Environmental Protection Agency
    Research Triangle Park, North Carolina  27711
    Telephone:   (919) 541-5578

4.   Copies of this document may be obtained from:
    U. .S. EPA Library (MD-35)
    Research Triangle Park, North Carolina  27711
    Telephone:   (919) 541-2777

    National Technical Information Service
    5285 Port Royal Road
    Springfield, Virginia  22161
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                             TABLE OF CONTENTS

Section                                                             Page

1    SUMMARY	1-1

     1.1   Summary of Changes Since Proposal 	  1-2

     1.2   Summary of Impacts of Promulgated Amendments  	  1-3
           1.2.1  Alternatives to the Promulgated Action 	  1-3
           1.2.2  Environmental Impacts of the Promulgated
                  Action	1-3
           1.2.3  Energy and Economic Impacts of the Promulgated
                  Action	1-3
           1.2.4  Other Considerations 	  1-3
                  1.2.4.1  Irreversible and Irretrievable
                           Commitment of Resources	• .  .  1-3
                  1.2.4.2  Environmental  and Energy Impacts of
                           Delayed Standards 	  1-4
                  1.2.4.3  Urban and Community Impacts 	  1-4

2    SUMMARY OF PUBLIC COMMENTS  	  2-1

     2.1   Test Methodology	2-1
           2.1.1  Mass Emissions	2-1
           2.1.2  Visible Emissions	  2-11

     2.2   Emission Limits	2-17
           2.2.1  Mass Emission Standard	  2-17
           2.2.2  Visible Emission Standard	2-19

     2.3   Costs of Testing	2-26

     2.4   Miscellaneous	2-27
                                 IV

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                              LIST OF TABLES
Table



2-1  List of Commenters
Page



2-2

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                                 1.   SUMMARY

     On October  21,  1974  (39  FR  37466),  standards  of  performance  were
proposed  under Section 111 of the Clean  Air Act  to control  particulate
matter emissions from electric arc  furnaces (EAF's) in  the  steel  industry.
Standards of performance  were promulgated on September  23,  1975
(40 FR 43850), and apply  to any  facility constructed, modified, or
reconstructed after  October 21,  1974.  Under the Clean  Air  Act amendments
of 1977,  standards of performance must be reviewed every 4  years  and
revised,  if appropriate.  On  April  21, 1980, a notice was published in
the Federal Register (45  FR 26910)  announcing such a review of the
standards of performance  for  EAF's  in the steel industry.   The review
found that fugitive  emissions capture technology had improved since
promulgation of the  existing  standards of performance for EAF's.   Another
finding was that argon-oxygen decarburization (AOD) vessels are a
significant source of particulate matter emissions in specialty steel
shops.   As a result  of these  findings, additional  data were collected on
the controlled emission levels from EAF's and AOD vessels to determine
how the standards should be revised.
     Revised standards of performance were proposed on August 17-,  1983.
The period for public comment extended through October 31,  1983,  and
seven written comments were received.  A public hearing was requested  by
one individual,  but this request was later withdrawn,  and no public
hearing was held.  The comments on the proposed standards,  together with
responses to each comment, are presented in this  document.   The comments
and responses serve as the basis  for the revisions  that have been  made
to the  proposed standards.
                                    1-1

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1.1  SUMMARY OF CHANGES SINCE PROPOSAL
     In response to public comments, certain changes have been made in
the proposed standards, and the more significant changes' are summarized
below.  All changes that have been made to the regulation are explained
fully in the responses to the comments.
     For sources built between October 21, 1974, and August 17, 1983,
Section 272(a)(3)(iii), which was in the original regulation but was
changed in the proposed revisions, is reinstated in the promulgated
regulation.  The related sections 274(a)(3), (a)(4), (b), (c), (e), and
(f) of the original regulation are also reinstated.   Sections 274(b) and
(c) have been revised, and Section 274(e), (f), and (g) have been
redesignated (f), (g), and (h).   These sections require continuous
monitoring of the flow rate through each capture hood and-the pressure
in the free space inside the furnace and require that the monitored flow
rates and pressure be maintained at baseline levels established during
the most recent performance or compliance test.
     Modular, multiple-stack, negative-pressure baghouses have been
included with 'positive-pressure baghouses as control devices that may be
monitored by Reference Method 9 observations in lieu of transmissometers.
     Sections 275(i) and 275a(c) have been revised to make it clear
that, where it is possible to determine that visible emissions at
multiple sites are attributable to only one incident of the visibl-e
emissions, one set of Reference Method 9 observations from the point of
highest opacity that directly relates to the cause (or location) of the
incident will be sufficient.
     In addition, because of the Agency's continued standards development
work, several other changes have been made in the standards.   Both
Subparts AA and AAa are revised to permit either periodic monitoring and
recording of fan motor amperage and damper position or continuous moni-
toring and periodic recording of flow rates.   In Subpart AA,  if fan motor
amperage/damper position monitoring is the chosen alternative, the monthly
operational status inspections that were proposed will  be required.
Sections 275(a)(l) and 275a(a)(4) have been revised to make it clear
that only Reference Method 5 is to be used on negative-pressure fabric
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 added to Subpart AA.   This section requires that when the "baseline"
 monitored values are  outside of acceptable ranges,  these values must be
 reported semiannually.   To be consistent with Subpart AA, Subpart AAa
 has  been revised to  require establishment of these  same "baseline" values.
 Semiannual  reporting  of values outside of the specified ranges is also
 required for Subpart  AAa.   Both Subparts AA and AAa have had a provision
 added to clarify the  requirements  in Sections 275(g)(2) and 275a(h)(2)
 of acceptance by the  Administrator.   When utilizing a performance test
 method that compensates for the emissions from the  facilities not subject
 to the provisions of  the standards,  the Administrator must be notified
 of the method to be used 30 days prior to the performance test and must
 approve the method.
 1.2   SUMMARY OF  IMPACTS OF PROMULGATED AMENDMENTS
 1.2.1  Alternatives to  the Promulgated Action
      The regulatory alternatives are  discussed in Chapter 6  of Volume  I
 of the background information  document (BID)  for the  revised standards
 (EPA-450/3-82-020a).  These regulatory-alternatives reflect  the different
 levels  of emission control  that were  analyzed in determining best
 demonstrated  technology, considering  costs, nonair quality health,
 environmental, and economic impacts for  EAF's  and AOD  vessels  in steel
 plants.   These alternatives  remain the  same.
 1.2.2   Environmental  Impacts of the Promulgated Action
      The  environmental  impacts resulting.from  the revised standards are
 described in  Chapter  7  of Volume I of  the BID.  These  impacts  remain the
 same.
 1-2.3   Energy and Economic  Impacts of  the Promulgated Action
      Energy and economic impacts resulting from the standard are
 discussed in  Chapters 7 and 9, respectively, of Volume I of the BID.  No
 changes  in these  impacts have occurred since the standards were proposed.
 1.2.4  Other  Considerations
     1-2-4.1  Irreversible and Irretrievable Commitment of Resources.
The regulatory alternatives defined in Chapter 6 of Volume I of the BID
would not preclude the development of future control options nor would
they curtail any beneficial use of resources.   The alternatives do not
involve short-term environmental gains at the expense of long-term

                                    1-3

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environmental losses, and the alternatives yield successively greater
short- and long-term environmental benefits.   Further, none of the
alternatives result in the irreversible and irretrievable commitment of
resources.  No change in these considerations has resulted since proposal
of the standards.
     1.2.4.2  Environmental and Energy Impacts of Delayed Standards.  As
discussed in Chapter 7 of Volume I of the BID, delay in the revised
standards would cause a similar delay in realizing the beneficial impacts
associated with the standard.  No changes in the potential effects of
delaying the standards have occurred since proposal of the revised
standards.
     1.2.4.3  Urban and Community .Impacts.  Urban and community impacts
of the standards are considered under economic impacts in Chapter 9 of
Volume I of the BID.  No changes in these impacts have occurred since
the standards were proposed.
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                       2.   SUMMARY OF PUBLIC COMMENTS

      A  list of commenters  and their affiliations  is presented in Table 2-1.
 Seven individuals  representing two steel  companies, two local government
 agencies,  two  trade  associations,  and one private citizen submitted
 written  comments during the public comment period.
      The comment letters often contained  several  comments.   Each comment
 is  addressed separately, and  the  commenter is  identified'by  the  appropriate
 docket number.
 2.1  TEST  METHODOLOGY
 2.1.1 Mass  Emissions
      Comment:   One commenter  (IV-D-6)  states that Reference  Method  50  is
 the most practical test method under  the  circumstances.
      Response:  No response is  necessary.
      Comment:   Commenter IV-D-4 considers  Reference Method 5D to  be
 unacceptable because the Environmental Protection Agency  (EPA) has  only
 shown that Method 5D yields results,similar to those obtained by Method 5;
 however, the EPA has not shown that Reference Method 5D is accurate and
 precise.  The commenter cites  Portland Cement v.  Ruckelshaus  (486 F.2d 375)
 and Chrysler v. DOT (472 F.2d  659) for the requirement that the test
 method used should be objective, repeatable, and precise.
     Another commenter (IV-D-7) also believes that the accuracy and
 precision of any proposed compliance sampling method should be demonstrated.
     Response:   Method 5D is an adaptation of Method 5 for the emission
 testing of positive-pressure fabric filters.  The sample collection and
 analysis procedures specified in Method 5D are identical to those in
Method 5, and,  therefore,  the Agency expects the precision of Method 5D
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 6
 7
          TABLE 2-1.   LIST OF COMMENTERS FOR THE REVISION TO THE
              NSPS FOR EAF'S AND AOD VESSELS IN STEEL PLANTS3
No.
1
2
3
4
Commenter
Steel Bar Mills Assoc.
(0. A. Dulle, Jr.)
C F & I Steel Corp.
(B. D. Egley)
National Steel Corp.
(J. G. Manda)
American Iron and Steel
Date of comment
9/2/83
10/14/83
10/28/83
10/27/83
Docket entry No.
IV-D-1
IV-D-2
IV-D-3
IV-D-4
  Institute
(E.  F. Young, Jr.)
Allegheny County (PA)         10/24/83
  Bureau of Air Pollution
  Control
(R.  J. Chleboski)-
Donald L. Shepherd            10/28/83
Illinois Environmental        10/28/83
  Protection Agency
(D.  J. Goodwin)
                                                               IV-D-5
IV-D-6
IV-D-7
aCopies of all correspondence received from commenters appear in
 Docket A-79-33.
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 to be similar to that of Method 5.   The absolute accuracy of a particulate
 emission sampling method is undeterminable, but the precision of Method 5
 results have been demonstrated over many years of testing.  Method 50 is
 discussed in greater detail on page 2-5.
      The issues of Reference Method 5D repeatability, objectivity, and
 precision were resolved during development of the emission limit for
 this regulation.   Method 50 was used as the-field test method for acquiring
 the data for this regulation,  and this method was applied to several
 different fabric  filter configurations.   (See BID,  Vol.  I, Appendix C for
 descriptions.) The precision  of the results  of these tests was  considered
 in developing the emission  limit for this  standard.
      Comment:   Commenter IV-D-4 believes  that Reference  Methods  5 and 5D
 are less appropriate than high-volume sampling for  the testing of positive-
 pressure fabric filters.  This  commenter  states that  the high-volume
 sampling method has been used predominantly to measure the emissions
 from EAF fabric filters.  However,  the EPA  has proposed  that Reference
 Method  5 or  5D should be used on positive-pressure  fabric  filters.  The
 EPA supported  this  change by presenting the results from two tests  using
 Reference Method  50 that show higher particulate  matter  concentrations
 than those obtained with the high-volume sampling method.   The commenter
 states  that  the EPA has  not clearly  shown which of these methods  is correct.
 The commenter  believes that the  high-volume sampling method  is better
 suited  to positive-pressure fabric filter exhaust conditions because  it
 is  designed  to  operate at low air velocities,  and it collects more
 sample weight  than  is collected  by Method 50.
     Two  other  commenters (IV-D-2 and  IV-D-5)  believe  that high-volume
 sampling  is  an  appropriate test  methodology for testing  positive-pressure
 fabric  filters.
     Commenter  (IV-D-5) believes that, for pressurized fabric filters
with gas  flow rates  under 100,000 acfm, high-volume sampling results in
emission  data that are about 20 percent lower than Method 5 sampling
 results.  At a  flow  rate of 100,000 acfm or greater, direct testing of
exhaust stacks becomes economical.
     Response:  The Agency proposed Method 5D  instead of high-volume
methods for sampling of positive-pressure fabric filters  for two  reasons.
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First, the Agency conducted simultaneous comparison tests using both
Method 5 equipment and high-volume samplers.  The data obtained from
these tests show that the high-volume particulate concentration results
were 70 to 85 percent lower than those indicated by the Method 5 equipment
on emissions from a positive-pressure fabric filter.  Results of other
comparisons between the two methods, both direct and indirect, also show
that high-volume sampling methods produce results lower than Method 5 or
Method 5D (docket entry IV-A-1).
     A subsequent conversation with Commenter IV-D-5, discussing a
20 percent difference between high-volume sampling and Method 5, dis-
closed that this was a subjective estimate  and was not based on any
direct comparisons (docket entry IV-E-4).
     Second, as is discussed further on page 2-5, the Agency has determined
that it is necessary to use demonstrably reliable equipment and multipoint
sampling to assure a representative collection of particulate emissions
from most emission sources, including fabric filters.  Method 5D incorporates
the multipoint sampling requirements with the use of reliable Method 5
equipment to provide a practical method for testing positive-pressure
fabric filters."
     Comment:  One commenter (IV-D-2) states that the diagrams presented
on'pages 37356 and 37357  of the  Federal Register proposal notice are
oversimplified and not typical  of the fabric  filter at .the commenter1s
facility, which has 32-compartments and does  not have a  ridge vent  roof.
     The commenter suggests using high-volume sampling as an alternative
to  Reference Method 5D, thus reducing the  number of sampling stations
 (in  the case of his fabric  filter,  from  32  to 2).   The commenter believes
that the costs of performance  testing would range from about $10,000 to
$24,000, for a Reference  Method 5 series of three test runs.  He states
 that high-volume  sampling would cost $5,000 to  $8,000.
      Another commenter  (IV-D-4)  expresses  concern that Reference Method  5D
 could be  used  by  enforcement personnel  for any  roof monitor  exhaust for
which other test  methods  have  not been  specified,  i.e.,  shop  roof  exhausts.
 Therefore,  the  commenter  recommends the high-volume sampling  method;
 alternatively,  Reference  Method 5D  should  be  forbidden  under
 40 CFR 52.12(c)(l)  for  State  implementation plan  (SIP)  enforcement.
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      Response:   As  noted in the preamble to the proposed revisions
 (48  FR 37348-9),  because the General  Provisions (40 CFR 60.8[e]) require
 that all  control  devices be testable,  some States have been requiring
 affected  facilities controlled with positive-pressure fabric filters to
 undertake the  expensive  retrofit of stacks or stack extensions  onto the
 fabric filter  for testing purposes.   This  situation was brought to the
 Agency's  attention  during development of this revised NSPS.   Reference
 Method 5D was  developed  in response to this situation to ensure the
 availability of  uniform  test procedures for positive-pressure fabric
 filters.
      Method 5D was  proposed because the Agency recognized the
 complications  involved in testing the  many different configurations of
 positive-pressure fabric filters.   The procedure  section of  Method 5D
 addresses  most of the sampling issues  for  these tests  including examples
 of the application  of the method  to multicompartment fabric  filters.
 The  requirement for multipoint sampling.for particulate  concentration  is
 necessary  to achieve representative results  because  of  the possibility
 of stratification of the gas  stream occurring  within a  positive-pressure
 fabric filter.   This stratification is  caused  by  incomplete  mixing of
 the  gas in the fabric filter  and  results in  varying  particulate
 concentrations across the  exhaust  gas  profile  of  the fabric  filter.
 Method 5D  represents a reasonable  balance  between the multipoint sampling
 requirements necessary to  achieve  representative  results  and  a
 recognition of the  practical  problems  of testing  the many different
 outlet configurations found on positive-pressure  fabric  filters.
     Method 50 is a procedure  based on  the  EPA Reference Method ..5  to
 accommodate testing of emission sites that do  not conform to  conventional
 exhaust configurations and is  appropriate  for  testing positive-pressure
 fabric  filters.  The commenter presumes that application of the high-
 volume method would reduce the number of sampling locations required for
 a test and concludes that the  costs of testing would be greatly reduced
with the use of high-volume methods.  The Agency has determined that
there  is a need for multipoint sampling and for testing a representative
 number of sampling  locations.  Use of high-volume sampling equipment
would  not preclude these  requirements.   Applying the multipoint sampling
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requirements of Method 5D to high-volume sampling may actually be more
expensive than testing with Method 5 equipment under the same require-
ments.  A greater number of samples might have to be analyzed because
more than one filter catch might be necessary for each-sample location
when using a high-volume sampling train.  Additional equipment, such as
a greater number of high-volume samplers and volume measurement devices,
might also be necessary.
     The commenter (IV-D-2) who cites the example of a 32-compartment
fabric filter with two end-vents apparently assumes that such a fabric
filter would require 32 sample locations using Method 5D.  Section 4.2.3
of Method 5 or 5D indicates that, if all 32 compartments are potential
measurement sites (i.e., no roof monitor or stack exists), 12 compartments
or 50 percent of the total number of compartments, whichever is greater,
must be tested.  For the commenter1s example, a maximum of 16 sites, not
32, need to be tested following Method 50.   However, six measurement
sites would need to be sampled per test run, in keeping with the require-
ment that the same number of sites be sampled for each test run.  It
should.be noted that, if the two end-vents comply with the stack con-
figuration requirements in Method 50; the number of test sites could be
reduced from 16 to 2.
     The basis of the commenter's estimated costs of a performance test
are not explained, and those costs presented in the proposal's preamble
are believed to be correct.  The costs to conduct a performance test
according to Reference Method 50 are explained in detail in Appendix 0
of Volume I of the BID.  These costs are based on the assumption that a
test may require between 4 to 8 person-days of field work.  The costs of
$5,000 to $8,000 include the test report.
     The applicability of Reference Method 50 was explained at proposal.
Uses of Method 50 other than on the exhaust of the positive-pressure fabric
filter were not endorsed and no data exist to support use of the Method
on other sources.
     Comment.  A commenter (IV-D-2) states that determining a velocity
profile, as required by Reference Method 2, for even a small fabric
filter such as the five-compartment fabric filter depicted in the proposal
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preamble, would be difficult because of the large area over the filter
compartments.
     Another commenter (IV-D-7) believes that Reference Method 2 yields
inaccurate measurements of the gas stream when gas velocities are very
low.
     Response:  Commenter IV-D-7 is correct about measurements of
velocities outside the range recommended by Method 2.  Section 4.3 of
Method 5D includes a provision for measuring inlet gas flow rates and
calculating average outlet gas velocities (using the known outlet area)
for use in isokinetic determinations for those sources whose outlet
velocities cannot be accurately measured using Method 2.   It is the
Agency's intent that velocity measurements be conducted at each outlet
sampling point if the velocity head exceeds 0.05 inch of water column
(in. w.c.).   However, the inlet sampling option is a reasonable
alternative when lower velocity conditions exist.   Other approaches to
measuring outlet gas velocity, such as micromanometers or special  low
velocity Pi tot tubes, may also be applied subject to advance approval by
the Administrator, as described at 40 CFR 60.8(b).
     Comment:  One commenter (IV-D-5) believes that there could be
problems calculating the gas velocity required for Reference Method 5D
sampling because leakage could occur between the inlet and outlet of the
fabric filter.  The commenter states that using the average gas velocity
at the inlet, corrected to outlet conditions as specified in Method 50,
is not as accurate as using velocity measurements  at each outlet site.
     Another commenter (IV-D-7) questions whether  it is appropriate to
accept inlet flow rate measurements to determine total  volumetric  flow.
     Commenter IV-D-2 states that Reference Method 5D is  not appropriate
for emission testing of positive-pressure fabric filters  because of
possible ambient air infiltration into the fabric  filter  and the high
costs of sampling each compartment.   As an example of problems  of  ambient
air infiltration, the commenter describes a basic  oxygen  furnace secondary
emission fabric filter at his facility where the entry level  at the
filter floor is open to the atmosphere.   The commenter states  that,  as  a
result, significant dilution of the exhaust stream occurs  at either the
top of the bags or at the exhaust portal.   On  the  other hand,  the  commenter
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also describes an EAF fabric filter with man-sized doors near the ports
where a "flue" type duct situation near the doors is unlikely to occur.
     Response:  There is no technical difficulty in using a flow balance
approach to determine fabric filter outlet air velocity, provided that
leaks of air into and out of the fabric filter structure are identified
and sealed.  The Agency addresses the issue of air leakage into or out
of the fabric filter with the note in Section 4.3 of Method 50.  This
note states:  "All sources of gas leakage into or out of the fabric
filter housing between the inlet measurement site and the outlet measure-
ment site must be blocked and made leak-tight."  This requirement would
apply when measurements at the inlet to the fabric filter are used to
calculate average gas velocity for isokinetic determinations and when
sources of ambient air in-leakage or emission leakage exist in the
housing.
     In using the words "leak-tight," it is the EPA's intent that major
air leakage sites, such as open grate floors and large access doors be
sealed adequately with relatively inexpensive plastic or fiberglass
materials.  This procedure .for preventing air in-leakage has been demon-
strated during the data collection process for this regulation.  The
positive-pressure characteristic of the fabric filters used in this
industry aids in identifying the location of most small  air leaks.
Those leaks that can be located should be sealed prior to, and for the
duration of, the test period.
     In promulgating Method 5D, the note in Section 4.3  has been moved
to the test procedures section to give it more visibility.  Also, the
note has been revised to state that the steps to block the leakages
should be taken prior to the emission measurements.
     Comment:  One commenter (IV-D-2) states that probe  supports would
be required at each sampling port because of the probe length required
to span even the smallest fabric filter module.
     Another commenter (IV-D-7) also believes that problems of probe
supports or probe rigidity should be considered in the test method.
     Response:  Rather than specify solutions in Method  5D to each
testing problem that might arise,.site specific testing  problems are
usually left to testing and shop personnel to resolve.  There are a
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 number of approaches to sampling over long traverses; for example,
 diametrically opposed sampling ports will reduce probe length by half,
 internally mounted cables or bars for probe supports will eliminate need
 for external structures, and sampling from a roof monitor or vent
 location will greatly reduce the traverse lengths.   Probe length require-
 ments did not pose problems in using Method 5D to acquire the data
 necessary to establish the NSPS for EAF's and ADD vessels in steel
 plants.
    .  Comment:   One commenter (IV-D-5) states that it is not necessary
 for the  test method to require both a volume of 160 dry standard cubic
 feet  (dscf)  and a sample weight of 50 milligrams (mg).   The commenter
 points out that emissions from some sources  are so  low that it could
 become necessary to test for up to 8 hours to collect a 50  mg sample.
 The commenter believes this amount of time is unreasonable,  especially
 for a clean  source.   The commenter believes  that the minimum sample
 volume of 160  dscf is adequate and recommends that  the  minimum sample
 weight of 50 mg be deleted.
      Response:   The Agency  agrees  with this  comment.   Proposed
 paragraph 60.275 of Subpart AA reflects this  decision,  but  proposed
 paragraph 60.275a of Subpart AAa mistakenly  included the  50  mg minimum
 catch requirement.   This  has  been  corrected  in  the  final  rulemaking  by
 amending  paragraph  60.275a  to  delete  the  50 mg  requirement.
      Comment:   Commenter  IV-D-7 questions  whether isokinetic  sampling  of
 the exhaust  gas  stream from  a  fabric  filter  i's  necessary  if  particulate
 matter emissions  are  in the  submicron range.
      Response:   Particle  size  distribution tests on  fabric filter exhausts
 have  shown that  the mass median diameter of the outlet particles is  some-
what  smaller than that of the  inlet particles, but  it is  not  necessarily
a submicron particle  size.  For emissions  from EAF operations, it is
expected  that the change  in mass median diameter from inlet to outlet
would be  very slight.  Therefore, unless  the inlet particle size
distribution is submicron, which is an unlikely occurrence for EAF and
AOD vessel emissions, the outlet particle size distribution will  probably
not be skewed toward the submicron range.   Isokinetic sampling must be
maintained to assure a representative collection of particles greater
than 2 microns.
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     Comment:   Commenter IV-D-7 questions whether the sampling probe is
heated and asks how to accomplish such heating, if necessary.
     Response:   Method 5D specifies sampling at or above the stack
temperature up to a nominal 248°F.   If Method 17 equipment is used, no
filter or probe heating is required.   Heating of the probe and filter
for Method 5 equipment is as specified in Method 5.   Heating techniques
are outlined in Method 5 reference material and include rheostat- or
thermostat-controlled nichrome wire for glass-lined probes and insulated
heating wire for metal probes.
     Comment:   Commenter IV-D-7 questions whether stack testing apparatus
can operate properly for the duration of a test, which is up to 4 hours.
     Response:   Properly designed and constructed Method 5 sampling
equipment will endure test periods much longer than 4 hours.  The parts
(usually industrial grade) that constitute the sampling train are
commonly available and, with normal operation and care, should operate
satisfactorily for indefinite periods.  The sampling periods for tests
in support of this regulation often exceeded 8 hours with few or no
equipment problems.-
     Comment:   Commenter IV-D-7 believes that design standards for
positive-pressure fabric filters should be considered in lieu of emission
testing requirements.
     Response:  Sections lll(h)(l) and (2) of the Clean Air Act require
that emission limits be established if it  is "feasible to prescribe or
enforce a standard of performance."  This  phrase 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" (Section lll[h][2]).  For this industry, feasible control
technology and test  methods exist, and,  thus,  design standards are not
permitted  in lieu of emission  limits.
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      Moreover,  in most cases,  it would not be possible to evaluate
 design  parameters alone to  predict compliance with the emission limit.
 This  is because there  are operational  parameters,  such as the timing and
 duration of  cleaning cycles or compartment air flow distribution,  that
 can affect fabric filter performance.
      Method  5D  was  proposed as a practical  emission testing  method.   It
 is appropriate  for  measuring the emission- levels from  positive-pressure
 fabric  filters,  and the costs  of testing  are  reasonable.
 2.1.2  Visible  Emissions
      Comment:   One  commenter (IV-D-4)  endorses  the use of Reference
 Method  9 as  an  alternative  to  transmissometers  for continuous  monitoring
 of positive-pressure fabric filters.   At  the  same  time, the  commenter
 believes  that continuous monitors  should  not  be required  on  modular,
 negative-pressure fabric filters  that  have  multiple  stacks.   Such  fabric
 filters  would require  multiple monitors,  which would significantly
 increase  the capital and operating costs.   Therefore,  the  commenter
 recommends that  Reference Method 9 be  allowed on both  modular,  negative-
 pressure  fabric  filters  and  positive-pressure fabric filters as an
 alternate method of continuous monitoring.
    •Response:   Two fabric  filter vendors were contacted  (docket
 entries  IV-E-1 and  IV-E-2)  for information  about current  installations
 and trends in the use  of modular, multiple-stack,   negative-pressure
 fabric filters.   The vendors confirmed the  EPA information that the
 industry trend is toward positive-pressure  fabric  filters.
     The commenter, a  representative of a trade association,  was also
 contacted (docket entry  IV-E-3), and he explained that a staff member's
 concern about possible future use of modular,  multiple-stack, negative-
 pressure fabric filters prompted the comment.   The  commenter was not
 aware of any installations of such fabric filters  or of plans for their
 use in the future.
     Although it is unlikely that modular, multiple-stack, negative-pressure
 fabric filters  will  be  used  extensively by the industry, the  Agency is
aware of three  such fabric filters in use to control emissions from
EAF's.  Therefore, it  is appropriate to permit Reference Method 9 visible
emission observations  by a certified observer  in lieu of a transmissometer
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to monitor visible emissions from such units, and Sections 273(c),
275(i), 273a(c), and 275a(c) of the regulations have been changed to
reflect this position.
     Comment:  One commenter (IV-D-5) supports the use of Reference
Method 9 visible emission observations as an alternative to transmisso-
meters.  However, the commenter does not believe that these observations
are necessary 5 days per week.   The commenter recommends making the
observations every third operating day because he believes that this
frequency is sufficient to ensure proper operation and maintenance of
positive-pressure fabric filters.
     Response:  The decision to permit Reference Method 9 visible emission
observations to monitor opacity from positive-pressure fabric filters
and modular, negative-pressure fabric filters with multiple stacks was
made because studies indicate that there are difficulties associated
with the use of one transmissometer to monitor multiple stacks or very
long path lengths (docket entry II-I-86).  The capital and operating
costs for installing multiple transmissometers, which may be necessary
in some cases, are considered to be unreasonable.  However, the Agency
continues to believe that, in general, continuous monitoring of visible
emissions from control  device stacks provides the best indication of the
status of operation and maintenance of the control device.  The require-
ment to observe visible emissions 5 days per week is based on our
engineering judgment that at least daily observations are necessary to
detect bag failure and to prevent associated excess emissions.  In view
of these considerations, requiring Reference Method 9 visible emission
observations once per day of operation for 5 days per week is reasonable
and appropriate.
     Comment:  One commenter (IV-D-4) states that the regulations allow
the use of Reference Method 9 in lieu of transmissometers for continuous
monitoring of positive-pressure fabric filters.  However, the preamble
(in two places) appears to allow no choice between visual opacity
monitoring by Reference Method 9 and continuous monitoring by a trans-
missometer on positive-pressure fabric filters.  Therefore, the commenter
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 recommends  that the preamble  be  corrected  to  reflect  the  regulation,
 which  is the appropriate position.
     Response:  The commenter is correct;  there  is  an  inconsistency
 between the proposal preamble and the  regulation.   The promulgation
 preamble will explain that, for  positive-pressure and modular,  multiple-
 stack, negative-pressure fabric  filters, it is permissible to have a
 certified visible emissions observer monitor  the opacity  of visible
 emissions in lieu of installing  a transmissometer.  Reference Method 9
 visible emission observations  must be  used to monitor the emissions from
 these  units if a transmissometer is not installed.
     Comment:  One commenter  (IV-D-4)  states that the EPA has not evaluated
 the accuracy or precision of  Method 9  for monitoring visible emissions
 from area'sources such as shop roof monitors.   The  commenter states that
 it is  essential for the EPA to establish the accuracy and precision of
 Method 9 for this type of source because (1) the method stipulates that
 the accuracy of the method must be taken into account when determining
 compliance; (2) the method provides information regarding its accuracy
 and precision only for sources of continuous emissions being discharged
                                -.
 through a stack; and (3) many variables exist which affect the accuracy
 and precision of EAF shop roof monitor opacity readings,  and these
 variables were not evaluated adequately when the EPA developed and
 adopted Method 9.   Some of the variables that must be evaluated include
 roof monitor size and geometry, air flow and velocity, orientation with
 respect to the sun,  various meteorological  factors,  fluctuations in the
 appearance of emissions, and scheduling of activities in  the shop.
 Therefore,  the commenter recommends that the EPA include  an alternative
 mass emission limitation in the regulation for process fugitives as an
 option available in  the event that the opacity limit cannot be met.
     The commenter notes that there is a published method for measuring
 shop roof mass emissions:   D.  Trozzo and J. Turnage, "Method for Deter-
mining Mass Particulate Emissions from Roof Monitors," Journal  of the
 Air Pollution Control  Association,  October 1981,  Volume 31,  Number 10.'
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     Response:  The "EPA Response to Remand Ordered by U.S. Court of
Appeals for the District of Columbia in Port!and-Cement Association v.
Ruckelshaus (486 F.2d 375, June 29, 1973)", discusses in detail the
reliability and accuracy of Reference Method 9 and accompanying certifi-
cation techniques for determining compliance with visible emission
standards.  On the basis of this response, the visible emission standard
included in the NSPS for portland cement plants was affirmed by the
Court on appeal in Portland Cement Association v. Train, 513 F.2d 506.
The data gathered in responding to the remand for portland cement plants
convincingly demonstrate that individual visible emission observers can,
for single runs, read the opacity of visible emissions within an acceptable
level of precision.   The accuracy of the Method is taken into account in
the enforcement process, as provided explicitly by Reference Method 9.
     Reference Method 9 is applicable "... for the determination of
the opacity of [visible] emissions from stationary sources pursuant to .  •
Section 60.11(b) ..." (40 CFR 60 Appendix A, Method 9).  As stated in
the method:  "Many stationary sources discharge visible emissions into
the atmosphere; these emissions are usually in the shape of a plume.
This method involves the determination of plume opacity by qualified
observers."  The major factors influencing plume opacity are:   particle
characteristics (particle size distribution, particle density, 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 characteristics
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 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.   Furthermore, Method 9
indicates how various meteorological conditions are to be taken into
account.  Thus, the ability to read the opacity of visible emissions
from roof monitors is not influenced by background anymore than is the
ability to read visible emissons from stacks.
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      The geometry of stacks and roof monitors do differ.   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,  therefore,  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,  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),  which ensures  that observed opacity is  minimized.
 When  the visible  emission standards  for this  industry were developed,
 visible  emission  observations were taken from existing furnace  shops
 with  typical roof monitor designs.   Thus, the effect of path  length  on
 opacity  is taken  into  account during development of  the standards,  and
 Reference Method  9 ensures  that compliance  with  the  standards  is  determined
 by  reading plumes across the shorter path length.
    -  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  applicable  to  plumes  from stacks,
 roof  monitors,  and other points of release.
      The test program  for each specific  source type  is  designed to
 account  for the variables that affect  the visible emissions of that
 specific source.  In the test program  for the NSPS that applies to EAF's
 and ADD vessels in steel plants,  the tests covered the entire heat
 cycle, thus accounting for  fluctuations  in the appearance of emissions
 and the scheduling of relevant activities in the shop.  In addition, the
 various facilities tested covered the  range  of roof monitor sizes and
configurations  and of air flows and velocities that are expected in the
 industry (see BID, Vol. 1,  Appendix C.).
     The use of visible emission standards is technically sound and
provides the most practical  and inexpensive  means to  ensure that affected
facilities are  properly maintained and operated.   The opacity of visible
emissions exiting the shop  roof monitor is a good indicator of the
performance of  the process  and fugitive emissions capture systems.
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Therefore, shop roof monitor visible emission opacity limits were selected
as the format for this standard.  Practical methodology does not exist
to obtain measurements of mass emissions discharged from shop roof
monitors.  The shop roof mass emission testing procedures suggested by
the commenter would be more expensive than Reference Method 9 observations
and, in some cases (where there is not only low exit velocity but possibly
negative pressure and fluctuating mass concentrations), would be highly
inaccurate and unreliable.  In addition, this shop roof mass emission
measurement technique has not yet been adequately tested and evaluated.
Therefore, a mass emission limit for fugitive emissions from the shop
roof would not be consistent with the requirements of the Clean Air Act.
     Comment:  One commenter (IV-D-2) states that it is not practical to
use Reference Method 9 observations to monitor fugitive emissions from
the dust handling equipment because of the difficulty of determining at
what point in the emission plume the opacity should be read.  The commenter
suggests that it would be more appropriate to require proper operation
of'the dust handling equipment, which could include routine operational
status- inspections.
     Response:  Reference Method 9, Section 2.3, specifies that opacity
observations must be made at the point of greatest opacity in that
portion of the plume where condensed water vapor is not present.  The
plumes that result from fugitive emissions from the dust-handling equipment
associated with EAF's in the steel industry would not be expected to
contain condensed water vapor because the temperatures of such plumes
are typically about 120° to 130°F.  Thus, there should be no difficulty
in determining at what point in the visible fugitive emission plume the
opacity should be read because a certified observer only needs to look
for the point of greatest opacity.
     Comment:  One commenter (IV-D-2) states that, in some cases, it
could be necessary to perform three Reference Method 9 opacity observations
at each site of visible emissions from a fabric filter to comply with
40 CFR 60.275a(c).  The commenter cites his equipment as an example:  a
positive-pressure fabric filter with 32 compartments, each of which is
discharged into a common outlet plenum that is open to the atmosphere at
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 each  end of  the  fabric  filter.   In  addition,  a  horizontal  slot  is  located
 on the front, bottom  side  of  each compartment.   Thus,  visible emissions
 resulting  from a broken  bag in any  one  compartment  could be  seen at
 three locations.  The commenter  concludes that  Section 275a(c)  would
 require 54 minutes of Reference  Method  9 observations  for  the one  incident.
      Response:   It is not  the Agency's  intent to create unnecessary work
 for owners or operators  of affected facilities.  Thus,  Sections 275(i)
 and 275a(c)  have been revised to make it clear  that, where it is possible
 to determine that visible  emissions at  multiple sites  are  attributable
 to only one  incident of  the visible emissions,  one  set of  Reference
 Method 9 observations from the point of highest opacity that directly
 relates to the cause (or location) of the incident  will be sufficient.
'2.2  EMISSION LIMITS
 2.2.1  Mass Emission Standard
     Comment:  One commenter (IV-D-5) states  that,  in  his experience,
well-designed and -maintained positive-pressure  fabric  filters can
 control  emissions far below 0.0052 gr/dscf; however, at this time,  the
 commenter  does not recommend a more stringent standard.
     Another commenter (IV-D-6) believes that it is the EPA's policy to
 base NSPS  emission limits  on the worst  performance  of any of the sources
 selected for testing without regard to  the condition of that worst
 source and any other mitigating factors.  The commenter further believes
 that this  policy rewards sources demonstrating a poor performance record.
The commenter recommends that the Agency establish  standards that
encourage  development of control  strategies that reduce emissions as
much as  possible.  The commenter notes that Figure 4-8 of the BID
 illustrates that only one  fabric filter test on an EAF exceeded
0.0030 gr/dscf,  and he concludes that this emission level  represents the
"degree  of emission limitation .  .  .  achievable through application of
the best technological system of continuous emission reduction . .  ."as
required by the  Clean Air Act.   The commenter states that lowering  the
mass emission standard for EAF's  and AOD vessels in steel  plants from
0.0052 to 0.0030 gr/dscf would reduce particulate matter emissions  by
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about 35 percent; therefore, the commenter recommends a mass emission
standard of 0.0030 gr/dscf for these sources.
     Response:  In establishing NSPS emission limits, the condition of
sources selected for testing is not disregarded, as commenter IV-D-6
suggests.  Rather, sources that are believed to be representative of
modern practice in one or more segments of the industry to be regulated
are selected for emission testing.   Moreover,  the operational status of
the source is documented and monitored continuously during testing to
ensure that the test data reflect an emission control level representative
of best demonstrated control technology (BDT).  Standards are set so
that well-designed, -operated, and -maintained plants, using BDT, can
achieve the standards over the range of conditions likely to recur in
the industry.
     In general, the data available on well-designed and well-operated
EAF fabric filters do indicate that such fabric filters can perform to
reduce emissions below 0.0052 gr/dscf.  In fact, except for one test run
at one facility, the data collected during the revision of this standard
demonstrated that fabric filters on EAF's can achieve an emission level
of less than 0.0031 gr/dscf.  However, the Agency agrees with the recom-
mendations made by Commenter IV-D-5 that the mass standard should not be
lowered.  This is because it was determined that, to guarantee fabric
filter compliance with a 0.0031 gr/dscf standard, vendors might increase
capital costs of fabric filters as much as 25 percent (docket nos. II-E-56,
II-E-57, II-E-58, II-E-60).  This increase in costs would result from
the increased air-to-cloth ratio and other design factors needed to
assure continuous compliance with the more stringent emission limit.
Thus, the incremental cost effectiveness of the more stringent standard
could be as much as $8,000/ton, which is considered to be unreasonable.
     According to the Clean Air Act amendments of 1977, Section lll(a)(l),
"a standard of performance shall reflect the degree of emission limitation
and the percentage reduction achievable through application of the best
technological system of continuous emission reduction which (taking into
consideration the cost of achieving such emission reduction, any nonair
quality health and environmental impact, and energy requirements) the
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Administrator determines  has  been  adequately  demonstrated."   The
0.0052  gr/dscf  limit  is based on the  data  available  from  well-controlled
and -operated facilities,  and it takes  into account  the costs of  complying
with the  standards.
2.2.2   Visible  Emission Standard
     Comment:   One commenter  (IV-D-7) states  that  the  proposal  preamble
explains  neither the  increase from 0  to 6  percent  opacity in  the  visible
emission  limit  for the roof monitor,  nor the  economic, energy,  or environ-
mental  impacts  associated  with this increase.  The commenter  believes
that, because the original standard allowed up to  20 percent  opacity
during  charging "and up to  40  percent  opacity  during tapping,  this standard
effectively applied only during melting.   He  concludes that the rationale
for establishing an overall 6 percent visible emission limit  presented
in the  proposal preamble is not applicable.   The commenter draws  this
conclusion because the maximum opacity varies from 0 to 5 percent,
although  the average  opacity  from  the tested  plants only  varies from 0
to 0.2  percent.  The  commenter notes that  available control technology
can achieve 3.3.percent opacity as an upper limit.  The commenter
recognizes the practical difficulties in implementing the 0 percent
visible emission standard, and he  recommends  that  the standard be set at
4 percent opacity and an exception be developed to address any infrequent
exceedance.  Furthermore,  he believes that Section 60.11(c) of the
General Provisions already accommodates those exceedances resulting from
start-ups, shut-downs, or malfunctions.   The commenter states that he
supports a simple regulation that provides a single emission  limit, and
he suggests that it might be appropriate to consider different visible
emission limits for carbon steel  EAF,  specialty steel EAF and AOD vessels.
     Another commenter (IV-D-6) notes that Table 4-5 of the BID
demonstrates that, except for one mill melting dirty scrap, all tested
plants could comply with a 5 percent visible emission limit on all
operations.  Thus, the commenter concludes that a 5 percent visible
emission limit for all operations is achievable and required by the
Clean Air Act.
     Response:  We agree with commenter IV-D-7 that a simple regulation
with a single emission limit is appropriate for this industry.  By
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setting the level of the standard to include all the data acquired
during entire heat cycles, provisions for exceedances are not necessary.
As was explained in the proposal preamble (48 FR 37347), the visible
emission limits were selected based on the performance of the capture
and control technologies that served as the basis for Regulatory Alternative B.
The economic, energy, and environmental impacts associated with the
revised standard were presented in the proposal preamble.
     Although the impacts associated with Regulatory Alternative C are'
considered reasonable, this alternative was not considered suitable as
the basis for national standards of performance because it is based on a
closed roof configuration which may aggravate worker and equipment heat
stress problems.  Operating experience with this roof configuration is
limited in areas of the country where ambient temperatures and humidity
are high.  Because the effects of heat stress cannot be fully evaluated
at this time, Regulatory Alternative B was selected as the basis for the
proposed revised standards.
     Twenty-seven hours of opacity observations were made of shop roof
visible emissions at two shops that utilized the capture systems upon
which Regulatory Alternative B is based.   These observations show that
the maximum opacity of shop roof visible emissions is 5 percent.  Visible
emission limits for NSPS are based on achieved levels at well-operated
and -maintained facilities that have installed what is considered to be
the best demonstrated control technology.   Visible emission limits are
not based on opacity values averaged for the period of the test (see
Portland Cement v.  Train, supra).   Thus,  the visible emission level for
this industry was set at 6 percent, which includes the highest Reference
Method 9 observation plus a reasonable margin of safety.  This methodology
was approved by the Court in Portland Cement v. Train, supra.  Under
Regulatory Alternative B, exceptions for exceedances are unnecessary
because the maximum opacity recorded was 5 percent throughout the heat
cycle.  As the commenter notes, 40 CFR 60.11(c) provides an exception
for nonnormal operation.  It is not appropriate to develop separate
visible emission limits for carbon steel  and specialty steel  shops
because the EAF's in both types of shops are operated and emit particulate
matter in a similar manner, and, also, it is possible that the EAF will
be operated alone from time to time in the specialty shop.
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     The plant  that  commenter  IV-D-6  refers  to  appears  to  be Plant H.
This plant was  among those  plants  tested  in  developing  the original
standards.  Control  technology for EAF's,  particularly  for their fugitive
emissions, has  improved  since  the  original test program.   Thus,  this
plant was not used as a  basis  for  the revised standards.   For the reasons
enumerated above, we believe that  6 percent  opacity  rather than  5 percent
is the appropriate level  for the visible  emission  standard for this
industry.  The  Clean Air Act requires that the  standard be achievable
and representative of the best demonstrated  control  technology,  taking
into consideration other factors such as  reasonable  cost.   The Court
decision in National  Lime Association-v.  EPA (627  F.2d  416 [1980])
requires that the standard  must be achievable under  all conditions
expected to recur, and,  in  this industry, this  includes the  use  of dirty
scrap.
     Comment:   One commenter (IV-D-4)  states that  the EPA  has  not adequately
documented that EAF  and  AOD vessel facilities subject to the  NSPS will
be able to comply with the  6 percent  visible emission limit  from  shop
roofs during charging and tapping  (processes likely  to  cause  the  greatest
fugitive emissions).   The commenter states that only two out  of  seven
plants tested were representative of  the recommended emission  capture
system that is the basis  for the standard (closed  roof over the furnace
and open elsewhere);  four plants have totally closed roofs (representa-
tive of a more effective  capture system); and one plant has a  completely
open roof monitor (representative of a less effective capture  system).
Forty-five 6-minute opacity readings were taken during charging and 24
6-minute readings were taken during tapping at the two plants  that were
representative.   This means that the standard is based on  less than
7 hours of relevant observations.   The" commenter believes that the
number of observations made on shops with a closed roof over the  furnace
is limited,  and, therefore,  these data should not be used as a basis for
the regulatory limit.  The commenter cites National Lime Association v.
EPA,  supra,  as an example of a case in which  the EPA failed to establish
the representativeness of the tested plants and the achievability of the
standard under adverse conditions.   The commenter recommends that excep-
tions  to the opacity  limits  be allowed during charging and tapping as
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are allowed in the original NSPS or that the preamble and regulation
address emission problems that occur because of equipment malfunctions.
Furthermore, the commenter recommends that any source meeting the EPA's
suggested equipment requirement but failing the opacity standard be
allowed to demonstrate compliance based on alternate mass emission
limitations.
     The commenter also questions the validity of the correlation between
the shop roof opacity and mass emission rates.  Because these estimated
mass emission rates were used to determine the ambient air quality
impacts, the commenter doubts the accuracy of the air quality impacts
upon which the need for the proposed regulatory limit is based.
     The commenter notes that Section 60.11(e) of the General Provisions
allows a source to exceed the visible emissions standard if the mass
standard is being met.
     Response:  The commenter is correct that the data base for the
control configuration recommended for the NSPS contains tests at two
facilities (Plants J and N) that "are representative of the suggested
technology (closed roof monitors over furnace only)" [Regulatory
Alternative B].  The commenter also points out that approximately 7 hours
of Reference Method 9 observations were made for the charging and tapping
portions of the heat cycle.  The total data base includes 27 hours of
Reference Method 9 observations during the course of entire heat cycles
at plants representative of the recommended technology.  This amount of
visible emission data acquired at representative plants is, in the
EPA's judgment, an adequate data base upon which to set a standard.
National Lime Association v.  EPA, which the commenter cites, does require
that the data be from representative facilities and that the standard be
achievable.  However, the Court did not specify any quantity of data that
must be acquired before a standard can be set, and the Agency believes
that the data are sufficient to demonstrate the achievability of the
standard because worst-case conditions for this industry were included
in the test program.  The questions of achievability of the standard and
limited data were raised by the American Iron and Steel Institute at the
National Air Pollution Control Techniques Advisory Committee meeting in
July 1982, prior to proposal  of the revised standards.   In response to
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 these concerns,  Plant N was visited and tested.   Even during furnace
 upset conditions,  when the fugitive emission capture system was receiving
 furnace emissions  at a rate estimated to be,almost 10 times higher than
 it would during  normal  furnace operation,  Plant  N achieved the standard.
 The maximum 6-minute average visible emission reading over a 2-day
 period that covered many entire heat cycles  was  3.3 percent.   All  of the
 data for Alternative B  demonstrate  that the  visible emission limit of
 6  percent is achievable.
      As noted in the proposal  preamble (48 FR 37346),  although most of
 the shops in the industry are  closed roof  or are changing  to closed
 roof,  and new sources  are expected  to be located in closed roof shops,
 Alternative B was  recommended  because the  effects  of heat  stress on
 workers and equipment  in  closed roof shops in some areas of the country
 were unknown.  The  Agency did  not want to  risk causing any facility to
 incur  problems with heat  stress to  achieve compliance with the  standards.
 The  commenter represents  the major  industry  trade  association,  and  this
 association's  comments  (II-D-67 and  II-E-54)  about possible  heat stress
 problems  in  closed  roof shops  persuaded  the  Agency to conclude  that the
 standard  should  allow the  less  stringent Regulatory  Alternative B.    As
 both the  trade association and the Agency recognized, there were few
 partially open shops in existence, and,  thus,  only  limited data could be
 acquired; however,   these  data  are considered  to be sufficient to set
 standards based  on  Regulatory Alternative B which  is "worst case" in
 terms  of emissions   to the atmosphere.
     Because the 27 hours of data acquired during charging, melting, and
 tapping demonstrate that the 6 percent visible emission limit can be
 achieved with best   demonstrated control technology, the Agency no longer
 believes that exceptions to the standard are  appropriate for the charging
 and tapping portions of the EAF heat cycle.  In addition,  it is not
 necessary to include an exception for equipment malfunctions in this
 standard because the General Provisions (40 CFR 60.11[c])  already provide
 relief for exceeding the standard during start-up, shutdown, and
malfunctions.
     Finally, Section 60.11(e) is not a provision that allows
substitution of a mass emission standard for  a visible emission standard.
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Rather, Section 60.11(e) provides that owners or operators of any
affected facility from any source category that meets the mass emission
standard but does not meet the visible emission standard may apply for
an individual visible emission standard tailored to the unique circum-
stances of their facility.  This individual standard applies for the
life of the affected facility and is automatically approved upon
demonstration that:  (1) the facility is in compliance with the mass
emission standard; (2) the facility and associated air pollution control
equipment were operated and maintained in a manner to minimize the
opacity of emissions during the performance tests; (3) the performance
tests were performed under the conditions established by the Administrator;
and (4) the facility and associated air pollution control equipment were
incapable of being adjusted or operated to meet the applicable opacity
standard.  For the reasons discussed^in Section 2.1.2, page 2-14, a mass
emission standard for fugitive emissions from shop roofs is not practical
at this time.  Therefore, Section 60.11(e> is not applicable to the shop
roof standard.
     As the commenter stated, the BID, Vol. I, page 6-16, states both
that estimated fugitive emission reduction efficiencies were based on a
review of the literature (e.g., II-A-8, II-I-68, and II-I-94),
observation of furnace capture technologies at the facilities tested,
and engineering judgment, and that this methodology is reasonable.  The
Agency did riot, as the commenter concludes, attempt to correlate observed
EAF shop roof opacities with mass emission rates.  The visible emission
standard and the mass emission standard are based on achieved emission
rates.  The estimated efficiencies were used to obtain estimated emissions
reductions required to calculate cost effectiveness values of the various
regulatory alternatives.  Dispersion modeling was used to predict the
contribution of emissions from EAF's and ADD vessels to the ambient
particulate concentration.  There was no attempt to establish any
relationship between the opacity of visible emissions and ambient air
concentrations.
     Comment:  One commenter (IV-D-4) states that the deletion of
Section 272(a)(3)(iii) for sources built between October 21, 1974, and
August 17, 1983, was not explained at proposal and is inappropriate.
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 This  subsection required compliance with the shop roof opacity standard
 only  when the flow rate through each capture hood and the pressure in
 the free space inside the furnace were being measured during a perfor-
 mance test.   The flow rates and pressure established at this time became
 "baseline."   At all  other times,  these operating conditions were required
 to  be maintained at  the baseline  values or better.   The commenter
 believes that the deletion of this paragraph results in the imposition
 of  a  new and  more stringent emission limit on shops  built to comply with
 the original  NSPS because these shops will  now have  to meet the shop
 opacity  standards during all  routine EAF operations.   The commenter
 believes that this is retroactive regulation of existing sources and
 exceeds  the EPA's authority under Section 111,of the Clean Air Act.   The
 commenter recommends  reinstatement of the paragraph.
      Response:   The deletion  of Section 272(a)(3)(iii)  from the standards
 is  not considered to  be  more  stringent regulation and occurred because
 it  was believed  that  not having to continuously monitor  the flow rate
 and pressure  would relieve  some of the monitoring burden  on owners  or
 operators  of  affected facilities.   Deletion  of this  section is  less
 expensive  for, and more  convenient to,  owners  or operators;  however,
 because  of the concern expressed  by the  commenter, the regulation has
 been  amended.   Sources built  between  October  21, 1974, and  August 17,
 1983,  will again  be responsible for continuously monitoring, and main-
 taining  at baseline values, the flow  rate through each capture  hood  and
 the pressure  in the free  space  inside  the furnace.  The shop roof visible
 emission standard  will apply  only  during performance  and compliance
 tests. Section 272(a)(3)(iii) and  related Sections 274(a)(3),  (a.)(4),
 (b),  (c),  (e), and (f) of the original regulation will be reinstated.
 Sections 274(b) and (c) have  been  revised, and Sections 274(e), (f),
 and (g)  have been  redesignated  (f), (g), and (h).
     Comment:   One commenter.(IV-D-7) states that he generally agrees
with the basis (improvements  in fugitive emissions capture technology
 and increase in use of positive-pressure fabric filters) for the
 amendments (the shop roof visible emission standard and permitting
 Reference Method 9 observations in lieu of a transmissometer for
                                  2-25

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positive-pressure fabric filters) to the NSPS for EAF's in steel plants,
and, thus supports the revisions to the standards.
     Response:  No response is necessary.
2.3  COSTS OF TESTING
     Comment:  One commenter (IV-D-2) states that compliance tests and
procedures required by 40 CFR 60.275a(b) should not be required for
facilities that exhibit no visible emissions (zero opacity).  The
commenter cites 48 FR 37344, Table 3, as evidence that the average
concentration of the mass emissions is lower than the standard even when
visible emissions exhibit opacities that are as high as 2.8 percent.
Thus, the commenter believes that the expense of installing sampling
ports and platforms should only be incurred if visible emissions are
observed.  The commenter states that sampling ports are just another
source for leakage in a positive-pressure fabric filter and require
additional maintenance.
     Response:  Visible emissions of zero opacity do not necessarily
mean that the mass emission standard is being achieved by a-control
device because visible emissions do not relate directly to mass emissions
but rather to mass concentration.  This is one of the reasons that
40 CFR 60.8(a) of the General Provisions requires all new facilities to
conduct performance test(s) and to furnish the Administrator a written
report of the results of such performance test(s).  Section 60.8(e)
requires that the owner or operator of an affected facility provide
testing facilities such as sampling ports, sampling platforms, safe
access to platforms, and utilities for sampling equipment.  Because
these sampling requirements are necessary for any new facility required
to comply with any standard, these requirements are not an additional
burden to .new EAF and AOD vessel facilities as a result of this NSPS.
Sampling ports on the fabric filter inlet side can be sealed effectively
against air  leakage and ports on the outlet side cause no leakage
problems because they are downstream of the bags.  Sampling ports do not
require significant maintenance.
     Comment:  One commenter (IV-D-2) states that monitoring fabric
filters during a compliance test would be time consuming and expensive,
                                  2-26

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 especially in the case of his 32-compartment fabric filter where each
 compartment would have to be checked for its sequence in the cleaning
 cycle,  damper positions,  broken bags,  etc.
      Response:   As explained in Section 2.1.1,  the maximum number of
 sampling sites  would be 16 for this fabric  filter.   Acquiring information
 on control  device conditions may be time consuming; however, this is
 part of any performance test and is essential  in evaluating the test
 results.   The Agency is aware of the time and  expense involved in testing
 the fabric filter,  and, therefore,  every attempt was made to simplify
 testing procedures  for a  multi-compartment  fabric filter.   The costs of
 testing were included in  the economic  analyses  of the standard.
      Comment:   One  commenter (IV-0-3)  states that the test log required
 by 40 CFR  60 Sections 275(c) and 275a(d), Item  23,  repeats all  of the
'information  required by Items  1 through  22  in these sections and,  thus,
 is unnecessary.   Furthermore,  the commenter believes that maintaining
 the log during  testing  could require the  use of an  additional  person,
 thereby increasing  the  cost  of testing.
      Response:  There is  sufficient information to  evaluate  the  testing
 procedure and accuracy  in  Items  1 through 22 to be  included  in the test
 reports  required  under  Sections  60.275 (c)  and  60.275a(d).   Therefore,   -
 item  23  (test log)  is not  necessary and has been  deleted.  Item  7 has
 also  been changed to  include test times, as well  as  test dates.
 2.4   MISCELLANEOUS
      Comment:  One commenter (IV-D-4) states that the requirement to
monitor the pressure  in the  free  space within the EAF is unnecessary.
The commenter states  that the quality of steel  produced is dependent
upon  furnace pressure, and the commenter does not believe that the EPA
has authority to require monitoring of operating parameters that do not
relate directly to control devices.   The commenter believes that it is
the owner or operator's obligation to control  emissions to the EPA-
specified limits and that he should be  allowed  to choose how to adjust
process  operations to achieve this objective.   Therefore, the commenter
recommends that the EPA delete the requirement  that EAF free space pres-
sure be  monitored/recorded.
                                  2-27

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     The commenter also questions what improvement in air quality can be
expected as a result of other monitoring requirements, such as those
stated in Section 60.274a(c) that requires the owner or operator to
perform monthly operational inspections of capture equipment and record
the deficiencies noted.  The commenter believes that the owner or
operator should be allowed to determine the frequency and type of
inspection and maintenance program that is most efficient for his
operation.
     Response:  Electric arc furnace facilities use pressure monitors
inside the furnace to measure the pressure in the free space because
this pressure is a critical parameter in steel production and, thus, is
routinely monitored and recorded at every facility.  This regulation
does not specify any pressure to be maintained, only that the pressure
be monitored and recorded.  The Agency may require monitoring of
parameters that indicate proper operation and maintenance, whether or
not they relate directly to control devices.  Records of the pressure
enable enforcement personnel to compare the pressure with the baseline-
pressure established during the performance test.  This parameter is an
indicator of the proper operation and maintenance and relates to
effectiveness of emission capture.
     The requirement that the capture equipment be visually inspected
and that all deficiencies be noted and corrected is critical to ensure
proper operation of the capture equipment at the levels observed during
the performance test.  The once per month frequency for inspections has
been determined to be reasonable.  The owner or operator may, of course,
increase the frequency of inspections.
     Comment:  One commenter (IV-D-4) states that the definitions of an
EAF affected facility in the BID, Vol. I, and in Section 271a(a) of the
regulation are not the same.  Also, the definitions presented do not
include all of the necessary equipment (such as cranes, ladles, additive
systems, etc.) for the production of molten steel.  The commenter recom-
mends that an EAF shop be defined as one which consists of all equipment
that must be required to produce molten steel.  The commenter states
that the BID does not make it clear that no one particular equipment
change would necessarily constitute reconstruction.  Thus, the commenter
recommends deletion of the specific equipment listing.
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      Response:   The affected facility definition in Section 271a(a) and
 the  identification  of components  (48 FR 37349 and BID Vol.  I,  page 5-3)
 that would  be  examined in  determinations of modification and
 reconstruction are  not the same.   Section 271a(a) defines the  EAF to
 which the proposed  regulation is  applicable.   On the other hand,  the
 proposal preamble and the  BID identify the components that can affect
 the  rate of emissions and,  thus,  compliance.   These definitions provide
 information appropriate to the specific context,  and there is  no  incon-
 sistency.   In  general,  modifications  are "any physical  or operational
 change to an existing facility which  results  in  an increase in the
 emission rate  to the  atmosphere of any pollutant to which a standard
 applies ..."  (40  CFR  60.14[a]).   Reconstruction means  the replacement
 of components  of an existing  facility  to such an  extent  that:   (1)  the
 fixed capital  cost  of the  new components exceeds  50 percent of the  fixed
 capital cost that would be  required to construct  a comparable  entirely
 new  facility,  and (2) it is technologically and  economically feasible to
 meet  the applicable standards  set  forth  in this part  (see 40 CFR
 60.15[a] and [b]).  Because it  can change the emission rate  or costs of
 control, for purposes of modification  and reconstruction  determinations,  '
 the emission control  equipment  is  included in  the  definition relating to
 these determinations.   However, the control equipment does  not  itself
 create emissions and, thus, is  not considered  to be part of  the affected
 facility for purposes of the  regulation.
     The commenter  requests that the definition of  the affected facility
 be expanded  to include  items  in a shop such as ladles, cranes,  and
 additive systems.   Available  information suggests  that ancillary equipment
 does not cause or contribute to emissions (see 48  FR 37340) or change
 the emission rate from an EAF and, thus, is not appropriate for inclusion
 in the definition of an EAF affected facility.  If the commenter1s
 additions were identified as affected facilities, they would be separate
 affected facilities.  The EAF is the practical integral  emission source
 and is, therefore,  the unit to which the proposed regulation applies. '
The Agency believes  that the terms EAF and shop in Section 271a(a)
 should remain as defined.
                                  2-29

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     With respect to deleting the paragraph containing examples of
equipment that might be examined in reconstruction considerations
(48 FR 37349), the preamble clearly states that no one of the changes
would constitute reconstruction, and, thus, no ambiguity exists that
would create the enforcement problem the commenter anticipates. The
equipment list merely suggests items to consider in making a
reconstruction determination.
     Comment:  One commenter (IV-D-2) states that there may be a carbon
monoxide (CO) hazard that would require use of airpacks by testing
personnel during either in-stack or high-volume testing.
     Response:  Of the 19 plants providing the test data used in
developing the data base to support the revised NSPS, 8 plants were
tested for CO; of those 8, only 4 had measurable CO in the gas downstream
of the collectors.  In none of the tests was it necessary that test
personnel use airpacks.  However, if a situation arises where CO is a
test hazard, the test personnel would be expected to use appropriate
equipment for which the costs would be negligible.
     Comment:  One commenter (IV-D-5) notes that jet pulse fabric filters
have not been given consideration in developing the revised standards
for EAF's and AOD's in steel plants.  The commenter states that the use
of these fabric filters is popular, and, therefore, he believes they
should be investigated.
     Response:  "Jet pulse" refers to a pulse-jet fabric filter cleaning
method.  At present, fabric filters using a reverse air flow cleaning
mechanism are typical on EAF's and AOD vessels in steel plants.  Of 21
plants visited during development of the original and the revised NSPS,
14 had fabric filters with a reverse air flow cleaning mechanism, 6 used
a shaker type mechanism, and only 1 used a pulse-jet cleaning mechanism.
The one fabric filter utilizing a pulse-jet cleaning mechanism was
tested during development of the revised standards and achieved the
standard even during furnace upset conditions.
     In summary, the pulse-jet fabric filter has been investigated and
can be used to comply with the proposed particulate mass emission limit.
This standard of performance is expressed as an emission limit to permit
the EAF owner or operator to select a control device of his own choosing
that will comply with the standard.
                                  2-30

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     Comment:  One commenter (IV-D-3) requests that the word "daily" 'be
deleted from 40 CFR 60 Sections 273(c) and 273a(c) and that the words
"Method 9" in these sections be replaced with "Section 275(i) [275a(c)]
of this subpart."  The commenter recommends these changes to make it
clear that Reference Method 9 visible emission observations are required
for not more than 5 days per week.
     Response:   Use of "daily" is confusing and,  thus, the commenter's
suggested change to the regulation has been made.
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                                    TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
 1. REPORT NO.
  EPA-450/3-82-020b
                                                            3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
  Electric Arc  Furnaces and Argon-Oxygen Decarburization
  Vessels in Steel  Plants—Background  Information for
  Promul-gated Standards of Performance
             5. REPORT DATE
              August  1984
             6. PERFORMING ORGANIZATION CODE
7, AUTHOR(S)
                                                            8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
  Office of Air  Quality  Planning and Standards
  U.  S. Environmental  Protection Agency
  Research Triangle  Park, North Carolina   27711
             10. PROGRAM ELEMENT NO.
             11. CONTRACT/GRANT NO.
                                                               68-02-3059
12. SPONSORING AGENCY NAME AND ADDRESS
  Director for Air  Quality Planning and  Standards
  Office of Air and Radiation
  U.  S. Environmental  Protection Agency
  Research Triangle Park,  North Carolina  27711
             13. TYPE OF REPORT AND PERIOD COVERED
             14. SPONSORING AGENCY CODE
                EPA/200/04
15. SUPPLEMENTARY NOTES
16. A8ST1
        \CT
       Standards o.f  performance for the control  of particulate matter emissions from
  electric arc furnaces  and argon-oxygen decarburization vessels  at  new, modified, or
;  reconstructed steel  plants are being promulgated under the authority of Sections 111,
  114,  and 301(a) of the Clean Air Act, as''amended.   These standards  would apply to
  those affected facilities that commence construction on or after August 17, 1983, the
  date  of original proposal.  This document contains a summary of the public comments
  on  the proposed revised standards and the EPA's responses, as well  as summary economic
  and environmental  impact statements.
 7.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
                                              b.lDENTlFIERS/OPEN ENDED TERMS
                                                                         c.  COSATI Field/Group
  Air Pollution
  Pollution Control
  Standards of Performance
  Steel  Plants
  Particulate Matter
Air Pollution  Control
 8. DISTRIBUTION STATEMENT
  Unlimited
                                              19. SECURITY CLASS (ThisReport)
                                               Unclassified
                          21. NO. OF PAGES

                                38
                                              20. SECURITY CLASS (Thispage)
                                               Unclassified
                          22. PRICE
EPA Form 2220—1 (Rev. 4—77)   PREVIOUS EDITION is OBSOLETE

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